Doug Anson
mbed TLS library
Dependents: HTTPClient-SSL WS_SERVER
Diff: polarssl/ssl_srv.c
- Revision:
- 0:137634ff4186
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/polarssl/ssl_srv.c Thu Jun 11 03:27:03 2015 +0000
@@ -0,0 +1,3628 @@
+/*
+ * SSLv3/TLSv1 server-side functions
+ *
+ * Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#if !defined(POLARSSL_CONFIG_FILE)
+#include "polarssl/config.h"
+#else
+#include POLARSSL_CONFIG_FILE
+#endif
+
+#if defined(POLARSSL_SSL_SRV_C)
+
+#include "polarssl/debug.h"
+#include "polarssl/ssl.h"
+
+#include <string.h>
+
+#if defined(POLARSSL_ECP_C)
+#include "polarssl/ecp.h"
+#endif
+
+#if defined(POLARSSL_PLATFORM_C)
+#include "polarssl/platform.h"
+#else
+#include <stdlib.h>
+#define polarssl_malloc malloc
+#define polarssl_free free
+#endif
+
+#if defined(POLARSSL_HAVE_TIME)
+#include <time.h>
+#endif
+
+#if defined(POLARSSL_SSL_SESSION_TICKETS)
+/* Implementation that should never be optimized out by the compiler */
+static void polarssl_zeroize( void *v, size_t n ) {
+ volatile unsigned char *p = v; while( n-- ) *p++ = 0;
+}
+
+/*
+ * Serialize a session in the following format:
+ * 0 . n-1 session structure, n = sizeof(ssl_session)
+ * n . n+2 peer_cert length = m (0 if no certificate)
+ * n+3 . n+2+m peer cert ASN.1
+ *
+ * Assumes ticket is NULL (always true on server side).
+ */
+static int ssl_save_session( const ssl_session *session,
+ unsigned char *buf, size_t buf_len,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+ size_t left = buf_len;
+#if defined(POLARSSL_X509_CRT_PARSE_C)
+ size_t cert_len;
+#endif /* POLARSSL_X509_CRT_PARSE_C */
+
+ if( left < sizeof( ssl_session ) )
+ return( -1 );
+
+ memcpy( p, session, sizeof( ssl_session ) );
+ p += sizeof( ssl_session );
+ left -= sizeof( ssl_session );
+
+#if defined(POLARSSL_X509_CRT_PARSE_C)
+ if( session->peer_cert == NULL )
+ cert_len = 0;
+ else
+ cert_len = session->peer_cert->raw.len;
+
+ if( left < 3 + cert_len )
+ return( -1 );
+
+ *p++ = (unsigned char)( cert_len >> 16 & 0xFF );
+ *p++ = (unsigned char)( cert_len >> 8 & 0xFF );
+ *p++ = (unsigned char)( cert_len & 0xFF );
+
+ if( session->peer_cert != NULL )
+ memcpy( p, session->peer_cert->raw.p, cert_len );
+
+ p += cert_len;
+#endif /* POLARSSL_X509_CRT_PARSE_C */
+
+ *olen = p - buf;
+
+ return( 0 );
+}
+
+/*
+ * Unserialise session, see ssl_save_session()
+ */
+static int ssl_load_session( ssl_session *session,
+ const unsigned char *buf, size_t len )
+{
+ const unsigned char *p = buf;
+ const unsigned char * const end = buf + len;
+#if defined(POLARSSL_X509_CRT_PARSE_C)
+ size_t cert_len;
+#endif /* POLARSSL_X509_CRT_PARSE_C */
+
+ if( p + sizeof( ssl_session ) > end )
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+ memcpy( session, p, sizeof( ssl_session ) );
+ p += sizeof( ssl_session );
+
+#if defined(POLARSSL_X509_CRT_PARSE_C)
+ if( p + 3 > end )
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+ cert_len = ( p[0] << 16 ) | ( p[1] << 8 ) | p[2];
+ p += 3;
+
+ if( cert_len == 0 )
+ {
+ session->peer_cert = NULL;
+ }
+ else
+ {
+ int ret;
+
+ if( p + cert_len > end )
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+ session->peer_cert = polarssl_malloc( sizeof( x509_crt ) );
+
+ if( session->peer_cert == NULL )
+ return( POLARSSL_ERR_SSL_MALLOC_FAILED );
+
+ x509_crt_init( session->peer_cert );
+
+ if( ( ret = x509_crt_parse_der( session->peer_cert,
+ p, cert_len ) ) != 0 )
+ {
+ x509_crt_free( session->peer_cert );
+ polarssl_free( session->peer_cert );
+ session->peer_cert = NULL;
+ return( ret );
+ }
+
+ p += cert_len;
+ }
+#endif /* POLARSSL_X509_CRT_PARSE_C */
+
+ if( p != end )
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+ return( 0 );
+}
+
+/*
+ * Create session ticket, secured as recommended in RFC 5077 section 4:
+ *
+ * struct {
+ * opaque key_name[16];
+ * opaque iv[16];
+ * opaque encrypted_state<0..2^16-1>;
+ * opaque mac[32];
+ * } ticket;
+ *
+ * (the internal state structure differs, however).
+ */
+static int ssl_write_ticket( ssl_context *ssl, size_t *tlen )
+{
+ int ret;
+ unsigned char * const start = ssl->out_msg + 10;
+ unsigned char *p = start;
+ unsigned char *state;
+ unsigned char iv[16];
+ size_t clear_len, enc_len, pad_len, i;
+
+ *tlen = 0;
+
+ if( ssl->ticket_keys == NULL )
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+ /* Write key name */
+ memcpy( p, ssl->ticket_keys->key_name, 16 );
+ p += 16;
+
+ /* Generate and write IV (with a copy for aes_crypt) */
+ if( ( ret = ssl->f_rng( ssl->p_rng, p, 16 ) ) != 0 )
+ return( ret );
+ memcpy( iv, p, 16 );
+ p += 16;
+
+ /*
+ * Dump session state
+ *
+ * After the session state itself, we still need room for 16 bytes of
+ * padding and 32 bytes of MAC, so there's only so much room left
+ */
+ state = p + 2;
+ if( ssl_save_session( ssl->session_negotiate, state,
+ SSL_MAX_CONTENT_LEN - ( state - ssl->out_ctr ) - 48,
+ &clear_len ) != 0 )
+ {
+ return( POLARSSL_ERR_SSL_CERTIFICATE_TOO_LARGE );
+ }
+ SSL_DEBUG_BUF( 3, "session ticket cleartext", state, clear_len );
+
+ /* Apply PKCS padding */
+ pad_len = 16 - clear_len % 16;
+ enc_len = clear_len + pad_len;
+ for( i = clear_len; i < enc_len; i++ )
+ state[i] = (unsigned char) pad_len;
+
+ /* Encrypt */
+ if( ( ret = aes_crypt_cbc( &ssl->ticket_keys->enc, AES_ENCRYPT,
+ enc_len, iv, state, state ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ /* Write length */
+ *p++ = (unsigned char)( ( enc_len >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( enc_len ) & 0xFF );
+ p = state + enc_len;
+
+ /* Compute and write MAC( key_name + iv + enc_state_len + enc_state ) */
+ sha256_hmac( ssl->ticket_keys->mac_key, 16, start, p - start, p, 0 );
+ p += 32;
+
+ *tlen = p - start;
+
+ SSL_DEBUG_BUF( 3, "session ticket structure", start, *tlen );
+
+ return( 0 );
+}
+
+/*
+ * Load session ticket (see ssl_write_ticket for structure)
+ */
+static int ssl_parse_ticket( ssl_context *ssl,
+ unsigned char *buf,
+ size_t len )
+{
+ int ret;
+ ssl_session session;
+ unsigned char *key_name = buf;
+ unsigned char *iv = buf + 16;
+ unsigned char *enc_len_p = iv + 16;
+ unsigned char *ticket = enc_len_p + 2;
+ unsigned char *mac;
+ unsigned char computed_mac[32];
+ size_t enc_len, clear_len, i;
+ unsigned char pad_len, diff;
+
+ SSL_DEBUG_BUF( 3, "session ticket structure", buf, len );
+
+ if( len < 34 || ssl->ticket_keys == NULL )
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+ enc_len = ( enc_len_p[0] << 8 ) | enc_len_p[1];
+ mac = ticket + enc_len;
+
+ if( len != enc_len + 66 )
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+ /* Check name, in constant time though it's not a big secret */
+ diff = 0;
+ for( i = 0; i < 16; i++ )
+ diff |= key_name[i] ^ ssl->ticket_keys->key_name[i];
+ /* don't return yet, check the MAC anyway */
+
+ /* Check mac, with constant-time buffer comparison */
+ sha256_hmac( ssl->ticket_keys->mac_key, 16, buf, len - 32,
+ computed_mac, 0 );
+
+ for( i = 0; i < 32; i++ )
+ diff |= mac[i] ^ computed_mac[i];
+
+ /* Now return if ticket is not authentic, since we want to avoid
+ * decrypting arbitrary attacker-chosen data */
+ if( diff != 0 )
+ return( POLARSSL_ERR_SSL_INVALID_MAC );
+
+ /* Decrypt */
+ if( ( ret = aes_crypt_cbc( &ssl->ticket_keys->dec, AES_DECRYPT,
+ enc_len, iv, ticket, ticket ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ /* Check PKCS padding */
+ pad_len = ticket[enc_len - 1];
+
+ ret = 0;
+ for( i = 2; i < pad_len; i++ )
+ if( ticket[enc_len - i] != pad_len )
+ ret = POLARSSL_ERR_SSL_BAD_INPUT_DATA;
+ if( ret != 0 )
+ return( ret );
+
+ clear_len = enc_len - pad_len;
+
+ SSL_DEBUG_BUF( 3, "session ticket cleartext", ticket, clear_len );
+
+ /* Actually load session */
+ if( ( ret = ssl_load_session( &session, ticket, clear_len ) ) != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "failed to parse ticket content" ) );
+ ssl_session_free( &session );
+ return( ret );
+ }
+
+#if defined(POLARSSL_HAVE_TIME)
+ /* Check if still valid */
+ if( (int) ( time( NULL) - session.start ) > ssl->ticket_lifetime )
+ {
+ SSL_DEBUG_MSG( 1, ( "session ticket expired" ) );
+ ssl_session_free( &session );
+ return( POLARSSL_ERR_SSL_SESSION_TICKET_EXPIRED );
+ }
+#endif
+
+ /*
+ * Keep the session ID sent by the client, since we MUST send it back to
+ * inform him we're accepting the ticket (RFC 5077 section 3.4)
+ */
+ session.length = ssl->session_negotiate->length;
+ memcpy( &session.id, ssl->session_negotiate->id, session.length );
+
+ ssl_session_free( ssl->session_negotiate );
+ memcpy( ssl->session_negotiate, &session, sizeof( ssl_session ) );
+
+ /* Zeroize instead of free as we copied the content */
+ polarssl_zeroize( &session, sizeof( ssl_session ) );
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_SESSION_TICKETS */
+
+#if defined(POLARSSL_SSL_SERVER_NAME_INDICATION)
+/*
+ * Wrapper around f_sni, allowing use of ssl_set_own_cert() but
+ * making it act on ssl->hanshake->sni_key_cert instead.
+ */
+static int ssl_sni_wrapper( ssl_context *ssl,
+ const unsigned char* name, size_t len )
+{
+ int ret;
+ ssl_key_cert *key_cert_ori = ssl->key_cert;
+
+ ssl->key_cert = NULL;
+ ret = ssl->f_sni( ssl->p_sni, ssl, name, len );
+ ssl->handshake->sni_key_cert = ssl->key_cert;
+
+ ssl->key_cert = key_cert_ori;
+
+ return( ret );
+}
+
+static int ssl_parse_servername_ext( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ int ret;
+ size_t servername_list_size, hostname_len;
+ const unsigned char *p;
+
+ SSL_DEBUG_MSG( 3, ( "parse ServerName extension" ) );
+
+ servername_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
+ if( servername_list_size + 2 != len )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ p = buf + 2;
+ while( servername_list_size > 0 )
+ {
+ hostname_len = ( ( p[1] << 8 ) | p[2] );
+ if( hostname_len + 3 > servername_list_size )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ if( p[0] == TLS_EXT_SERVERNAME_HOSTNAME )
+ {
+ ret = ssl_sni_wrapper( ssl, p + 3, hostname_len );
+ if( ret != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_sni_wrapper", ret );
+ ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL,
+ SSL_ALERT_MSG_UNRECOGNIZED_NAME );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ return( 0 );
+ }
+
+ servername_list_size -= hostname_len + 3;
+ p += hostname_len + 3;
+ }
+
+ if( servername_list_size != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_SERVER_NAME_INDICATION */
+
+static int ssl_parse_renegotiation_info( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ int ret;
+
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
+ {
+ /* Check verify-data in constant-time. The length OTOH is no secret */
+ if( len != 1 + ssl->verify_data_len ||
+ buf[0] != ssl->verify_data_len ||
+ safer_memcmp( buf + 1, ssl->peer_verify_data,
+ ssl->verify_data_len ) != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
+
+ if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+ return( ret );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ }
+ else
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+ {
+ if( len != 1 || buf[0] != 0x0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
+
+ if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+ return( ret );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
+ }
+
+ return( 0 );
+}
+
+#if defined(POLARSSL_SSL_PROTO_TLS1_2) && \
+ defined(POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED)
+static int ssl_parse_signature_algorithms_ext( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ size_t sig_alg_list_size;
+ const unsigned char *p;
+ const unsigned char *end = buf + len;
+ const int *md_cur;
+
+
+ sig_alg_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
+ if( sig_alg_list_size + 2 != len ||
+ sig_alg_list_size % 2 != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /*
+ * For now, ignore the SignatureAlgorithm part and rely on offered
+ * ciphersuites only for that part. To be fixed later.
+ *
+ * So, just look at the HashAlgorithm part.
+ */
+ for( md_cur = md_list(); *md_cur != POLARSSL_MD_NONE; md_cur++ ) {
+ for( p = buf + 2; p < end; p += 2 ) {
+ if( *md_cur == (int) ssl_md_alg_from_hash( p[0] ) ) {
+ ssl->handshake->sig_alg = p[0];
+ goto have_sig_alg;
+ }
+ }
+ }
+
+ /* Some key echanges do not need signatures at all */
+ SSL_DEBUG_MSG( 3, ( "no signature_algorithm in common" ) );
+ return( 0 );
+
+have_sig_alg:
+ SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: %d",
+ ssl->handshake->sig_alg ) );
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_PROTO_TLS1_2 &&
+ POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED */
+
+#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
+static int ssl_parse_supported_elliptic_curves( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ size_t list_size, our_size;
+ const unsigned char *p;
+ const ecp_curve_info *curve_info, **curves;
+
+ list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
+ if( list_size + 2 != len ||
+ list_size % 2 != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /* Should never happen unless client duplicates the extension */
+ if( ssl->handshake->curves != NULL )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /* Don't allow our peer to make us allocate too much memory,
+ * and leave room for a final 0 */
+ our_size = list_size / 2 + 1;
+ if( our_size > POLARSSL_ECP_DP_MAX )
+ our_size = POLARSSL_ECP_DP_MAX;
+
+ if( ( curves = polarssl_malloc( our_size * sizeof( *curves ) ) ) == NULL )
+ return( POLARSSL_ERR_SSL_MALLOC_FAILED );
+
+ /* explicit void pointer cast for buggy MS compiler */
+ memset( (void *) curves, 0, our_size * sizeof( *curves ) );
+ ssl->handshake->curves = curves;
+
+ p = buf + 2;
+ while( list_size > 0 && our_size > 1 )
+ {
+ curve_info = ecp_curve_info_from_tls_id( ( p[0] << 8 ) | p[1] );
+
+ if( curve_info != NULL )
+ {
+ *curves++ = curve_info;
+ our_size--;
+ }
+
+ list_size -= 2;
+ p += 2;
+ }
+
+ return( 0 );
+}
+
+static int ssl_parse_supported_point_formats( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ size_t list_size;
+ const unsigned char *p;
+
+ list_size = buf[0];
+ if( list_size + 1 != len )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ p = buf + 2;
+ while( list_size > 0 )
+ {
+ if( p[0] == POLARSSL_ECP_PF_UNCOMPRESSED ||
+ p[0] == POLARSSL_ECP_PF_COMPRESSED )
+ {
+ ssl->handshake->ecdh_ctx.point_format = p[0];
+ SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
+ return( 0 );
+ }
+
+ list_size--;
+ p++;
+ }
+
+ return( 0 );
+}
+#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */
+
+#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
+static int ssl_parse_max_fragment_length_ext( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ if( len != 1 || buf[0] >= SSL_MAX_FRAG_LEN_INVALID )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->session_negotiate->mfl_code = buf[0];
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */
+
+#if defined(POLARSSL_SSL_TRUNCATED_HMAC)
+static int ssl_parse_truncated_hmac_ext( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ if( len != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ((void) buf);
+
+ if( ssl->trunc_hmac == SSL_TRUNC_HMAC_ENABLED )
+ ssl->session_negotiate->trunc_hmac = SSL_TRUNC_HMAC_ENABLED;
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_TRUNCATED_HMAC */
+
+#if defined(POLARSSL_SSL_ENCRYPT_THEN_MAC)
+static int ssl_parse_encrypt_then_mac_ext( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ if( len != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ((void) buf);
+
+ if( ssl->encrypt_then_mac == SSL_ETM_ENABLED &&
+ ssl->minor_ver != SSL_MINOR_VERSION_0 )
+ {
+ ssl->session_negotiate->encrypt_then_mac = SSL_ETM_ENABLED;
+ }
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_ENCRYPT_THEN_MAC */
+
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+static int ssl_parse_extended_ms_ext( ssl_context *ssl,
+ const unsigned char *buf,
+ size_t len )
+{
+ if( len != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ((void) buf);
+
+ if( ssl->extended_ms == SSL_EXTENDED_MS_ENABLED &&
+ ssl->minor_ver != SSL_MINOR_VERSION_0 )
+ {
+ ssl->handshake->extended_ms = SSL_EXTENDED_MS_ENABLED;
+ }
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
+#if defined(POLARSSL_SSL_SESSION_TICKETS)
+static int ssl_parse_session_ticket_ext( ssl_context *ssl,
+ unsigned char *buf,
+ size_t len )
+{
+ int ret;
+
+ if( ssl->session_tickets == SSL_SESSION_TICKETS_DISABLED )
+ return( 0 );
+
+ /* Remember the client asked us to send a new ticket */
+ ssl->handshake->new_session_ticket = 1;
+
+ SSL_DEBUG_MSG( 3, ( "ticket length: %d", len ) );
+
+ if( len == 0 )
+ return( 0 );
+
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
+ {
+ SSL_DEBUG_MSG( 3, ( "ticket rejected: renegotiating" ) );
+ return( 0 );
+ }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+
+ /*
+ * Failures are ok: just ignore the ticket and proceed.
+ */
+ if( ( ret = ssl_parse_ticket( ssl, buf, len ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_parse_ticket", ret );
+ return( 0 );
+ }
+
+ SSL_DEBUG_MSG( 3, ( "session successfully restored from ticket" ) );
+
+ ssl->handshake->resume = 1;
+
+ /* Don't send a new ticket after all, this one is OK */
+ ssl->handshake->new_session_ticket = 0;
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_SESSION_TICKETS */
+
+#if defined(POLARSSL_SSL_ALPN)
+static int ssl_parse_alpn_ext( ssl_context *ssl,
+ const unsigned char *buf, size_t len )
+{
+ size_t list_len, cur_len, ours_len;
+ const unsigned char *theirs, *start, *end;
+ const char **ours;
+
+ /* If ALPN not configured, just ignore the extension */
+ if( ssl->alpn_list == NULL )
+ return( 0 );
+
+ /*
+ * opaque ProtocolName<1..2^8-1>;
+ *
+ * struct {
+ * ProtocolName protocol_name_list<2..2^16-1>
+ * } ProtocolNameList;
+ */
+
+ /* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */
+ if( len < 4 )
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+
+ list_len = ( buf[0] << 8 ) | buf[1];
+ if( list_len != len - 2 )
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+
+ /*
+ * Use our order of preference
+ */
+ start = buf + 2;
+ end = buf + len;
+ for( ours = ssl->alpn_list; *ours != NULL; ours++ )
+ {
+ ours_len = strlen( *ours );
+ for( theirs = start; theirs != end; theirs += cur_len )
+ {
+ /* If the list is well formed, we should get equality first */
+ if( theirs > end )
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+
+ cur_len = *theirs++;
+
+ /* Empty strings MUST NOT be included */
+ if( cur_len == 0 )
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+
+ if( cur_len == ours_len &&
+ memcmp( theirs, *ours, cur_len ) == 0 )
+ {
+ ssl->alpn_chosen = *ours;
+ return( 0 );
+ }
+ }
+ }
+
+ /* If we get there, no match was found */
+ ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL,
+ SSL_ALERT_MSG_NO_APPLICATION_PROTOCOL );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+}
+#endif /* POLARSSL_SSL_ALPN */
+
+/*
+ * Auxiliary functions for ServerHello parsing and related actions
+ */
+
+#if defined(POLARSSL_X509_CRT_PARSE_C)
+/*
+ * Return 0 if the given key uses one of the acceptable curves, -1 otherwise
+ */
+#if defined(POLARSSL_ECDSA_C)
+static int ssl_check_key_curve( pk_context *pk,
+ const ecp_curve_info **curves )
+{
+ const ecp_curve_info **crv = curves;
+ ecp_group_id grp_id = pk_ec( *pk )->grp.id;
+
+ while( *crv != NULL )
+ {
+ if( (*crv)->grp_id == grp_id )
+ return( 0 );
+ crv++;
+ }
+
+ return( -1 );
+}
+#endif /* POLARSSL_ECDSA_C */
+
+/*
+ * Try picking a certificate for this ciphersuite,
+ * return 0 on success and -1 on failure.
+ */
+static int ssl_pick_cert( ssl_context *ssl,
+ const ssl_ciphersuite_t * ciphersuite_info )
+{
+ ssl_key_cert *cur, *list, *fallback = NULL;
+ pk_type_t pk_alg = ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
+ int flags;
+
+#if defined(POLARSSL_SSL_SERVER_NAME_INDICATION)
+ if( ssl->handshake->sni_key_cert != NULL )
+ list = ssl->handshake->sni_key_cert;
+ else
+#endif
+ list = ssl->handshake->key_cert;
+
+ if( pk_alg == POLARSSL_PK_NONE )
+ return( 0 );
+
+ SSL_DEBUG_MSG( 3, ( "ciphersuite requires certificate" ) );
+
+ for( cur = list; cur != NULL; cur = cur->next )
+ {
+ SSL_DEBUG_CRT( 3, "candidate certificate chain, certificate",
+ cur->cert );
+
+ if( ! pk_can_do( cur->key, pk_alg ) )
+ {
+ SSL_DEBUG_MSG( 3, ( "certificate mismatch: key type" ) );
+ continue;
+ }
+
+ /*
+ * This avoids sending the client a cert it'll reject based on
+ * keyUsage or other extensions.
+ *
+ * It also allows the user to provision different certificates for
+ * different uses based on keyUsage, eg if they want to avoid signing
+ * and decrypting with the same RSA key.
+ */
+ if( ssl_check_cert_usage( cur->cert, ciphersuite_info,
+ SSL_IS_SERVER, &flags ) != 0 )
+ {
+ SSL_DEBUG_MSG( 3, ( "certificate mismatch: "
+ "(extended) key usage extension" ) );
+ continue;
+ }
+
+#if defined(POLARSSL_ECDSA_C)
+ if( pk_alg == POLARSSL_PK_ECDSA &&
+ ssl_check_key_curve( cur->key, ssl->handshake->curves ) != 0 )
+ {
+ SSL_DEBUG_MSG( 3, ( "certificate mismatch: elliptic curve" ) );
+ continue;
+ }
+#endif
+
+ /*
+ * Try to select a SHA-1 certificate for pre-1.2 clients, but still
+ * present them a SHA-higher cert rather than failing if it's the only
+ * one we got that satisfies the other conditions.
+ */
+ if( ssl->minor_ver < SSL_MINOR_VERSION_3 &&
+ cur->cert->sig_md != POLARSSL_MD_SHA1 )
+ {
+ if( fallback == NULL )
+ fallback = cur;
+ {
+ SSL_DEBUG_MSG( 3, ( "certificate not preferred: "
+ "sha-2 with pre-TLS 1.2 client" ) );
+ continue;
+ }
+ }
+
+ /* If we get there, we got a winner */
+ break;
+ }
+
+ if( cur == NULL )
+ cur = fallback;
+
+
+ /* Do not update ssl->handshake->key_cert unless the is a match */
+ if( cur != NULL )
+ {
+ ssl->handshake->key_cert = cur;
+ SSL_DEBUG_CRT( 3, "selected certificate chain, certificate",
+ ssl->handshake->key_cert->cert );
+ return( 0 );
+ }
+
+ return( -1 );
+}
+#endif /* POLARSSL_X509_CRT_PARSE_C */
+
+/*
+ * Check if a given ciphersuite is suitable for use with our config/keys/etc
+ * Sets ciphersuite_info only if the suite matches.
+ */
+static int ssl_ciphersuite_match( ssl_context *ssl, int suite_id,
+ const ssl_ciphersuite_t **ciphersuite_info )
+{
+ const ssl_ciphersuite_t *suite_info;
+
+ suite_info = ssl_ciphersuite_from_id( suite_id );
+ if( suite_info == NULL )
+ {
+ SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( POLARSSL_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ SSL_DEBUG_MSG( 3, ( "trying ciphersuite: %s", suite_info->name ) );
+
+ if( suite_info->min_minor_ver > ssl->minor_ver ||
+ suite_info->max_minor_ver < ssl->minor_ver )
+ {
+ SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: version" ) );
+ return( 0 );
+ }
+
+ if( ssl->arc4_disabled == SSL_ARC4_DISABLED &&
+ suite_info->cipher == POLARSSL_CIPHER_ARC4_128 )
+ {
+ SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: rc4" ) );
+ return( 0 );
+ }
+
+#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
+ if( ssl_ciphersuite_uses_ec( suite_info ) &&
+ ( ssl->handshake->curves == NULL ||
+ ssl->handshake->curves[0] == NULL ) )
+ {
+ SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: "
+ "no common elliptic curve" ) );
+ return( 0 );
+ }
+#endif
+
+#if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED)
+ /* If the ciphersuite requires a pre-shared key and we don't
+ * have one, skip it now rather than failing later */
+ if( ssl_ciphersuite_uses_psk( suite_info ) &&
+ ssl->f_psk == NULL &&
+ ( ssl->psk == NULL || ssl->psk_identity == NULL ||
+ ssl->psk_identity_len == 0 || ssl->psk_len == 0 ) )
+ {
+ SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no pre-shared key" ) );
+ return( 0 );
+ }
+#endif
+
+#if defined(POLARSSL_X509_CRT_PARSE_C)
+ /*
+ * Final check: if ciphersuite requires us to have a
+ * certificate/key of a particular type:
+ * - select the appropriate certificate if we have one, or
+ * - try the next ciphersuite if we don't
+ * This must be done last since we modify the key_cert list.
+ */
+ if( ssl_pick_cert( ssl, suite_info ) != 0 )
+ {
+ SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: "
+ "no suitable certificate" ) );
+ return( 0 );
+ }
+#endif
+
+ *ciphersuite_info = suite_info;
+ return( 0 );
+}
+
+#if defined(POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
+static int ssl_parse_client_hello_v2( ssl_context *ssl )
+{
+ int ret, got_common_suite;
+ unsigned int i, j;
+ size_t n;
+ unsigned int ciph_len, sess_len, chal_len;
+ unsigned char *buf, *p;
+ const int *ciphersuites;
+ const ssl_ciphersuite_t *ciphersuite_info;
+
+ SSL_DEBUG_MSG( 2, ( "=> parse client hello v2" ) );
+
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
+ {
+ SSL_DEBUG_MSG( 1, ( "client hello v2 illegal for renegotiation" ) );
+
+ if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+ return( ret );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+
+ buf = ssl->in_hdr;
+
+ SSL_DEBUG_BUF( 4, "record header", buf, 5 );
+
+ SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d",
+ buf[2] ) );
+ SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d",
+ ( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) );
+ SSL_DEBUG_MSG( 3, ( "client hello v2, max. version: [%d:%d]",
+ buf[3], buf[4] ) );
+
+ /*
+ * SSLv2 Client Hello
+ *
+ * Record layer:
+ * 0 . 1 message length
+ *
+ * SSL layer:
+ * 2 . 2 message type
+ * 3 . 4 protocol version
+ */
+ if( buf[2] != SSL_HS_CLIENT_HELLO ||
+ buf[3] != SSL_MAJOR_VERSION_3 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF;
+
+ if( n < 17 || n > 512 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->major_ver = SSL_MAJOR_VERSION_3;
+ ssl->minor_ver = ( buf[4] <= ssl->max_minor_ver )
+ ? buf[4] : ssl->max_minor_ver;
+
+ if( ssl->minor_ver < ssl->min_minor_ver )
+ {
+ SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum"
+ " [%d:%d] < [%d:%d]",
+ ssl->major_ver, ssl->minor_ver,
+ ssl->min_major_ver, ssl->min_minor_ver ) );
+
+ ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL,
+ SSL_ALERT_MSG_PROTOCOL_VERSION );
+ return( POLARSSL_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
+ }
+
+ ssl->handshake->max_major_ver = buf[3];
+ ssl->handshake->max_minor_ver = buf[4];
+
+ if( ( ret = ssl_fetch_input( ssl, 2 + n ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
+ return( ret );
+ }
+
+ ssl->handshake->update_checksum( ssl, buf + 2, n );
+
+ buf = ssl->in_msg;
+ n = ssl->in_left - 5;
+
+ /*
+ * 0 . 1 ciphersuitelist length
+ * 2 . 3 session id length
+ * 4 . 5 challenge length
+ * 6 . .. ciphersuitelist
+ * .. . .. session id
+ * .. . .. challenge
+ */
+ SSL_DEBUG_BUF( 4, "record contents", buf, n );
+
+ ciph_len = ( buf[0] << 8 ) | buf[1];
+ sess_len = ( buf[2] << 8 ) | buf[3];
+ chal_len = ( buf[4] << 8 ) | buf[5];
+
+ SSL_DEBUG_MSG( 3, ( "ciph_len: %d, sess_len: %d, chal_len: %d",
+ ciph_len, sess_len, chal_len ) );
+
+ /*
+ * Make sure each parameter length is valid
+ */
+ if( ciph_len < 3 || ( ciph_len % 3 ) != 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ if( sess_len > 32 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ if( chal_len < 8 || chal_len > 32 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ if( n != 6 + ciph_len + sess_len + chal_len )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
+ buf + 6, ciph_len );
+ SSL_DEBUG_BUF( 3, "client hello, session id",
+ buf + 6 + ciph_len, sess_len );
+ SSL_DEBUG_BUF( 3, "client hello, challenge",
+ buf + 6 + ciph_len + sess_len, chal_len );
+
+ p = buf + 6 + ciph_len;
+ ssl->session_negotiate->length = sess_len;
+ memset( ssl->session_negotiate->id, 0,
+ sizeof( ssl->session_negotiate->id ) );
+ memcpy( ssl->session_negotiate->id, p, ssl->session_negotiate->length );
+
+ p += sess_len;
+ memset( ssl->handshake->randbytes, 0, 64 );
+ memcpy( ssl->handshake->randbytes + 32 - chal_len, p, chal_len );
+
+ /*
+ * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
+ */
+ for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 )
+ {
+ if( p[0] == 0 && p[1] == 0 && p[2] == SSL_EMPTY_RENEGOTIATION_INFO )
+ {
+ SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation == SSL_RENEGOTIATION )
+ {
+ SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV "
+ "during renegotiation" ) );
+
+ if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+ return( ret );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+ ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
+ break;
+ }
+ }
+
+#if defined(POLARSSL_SSL_FALLBACK_SCSV)
+ for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 )
+ {
+ if( p[0] == 0 &&
+ p[1] == (unsigned char)( ( SSL_FALLBACK_SCSV >> 8 ) & 0xff ) &&
+ p[2] == (unsigned char)( ( SSL_FALLBACK_SCSV ) & 0xff ) )
+ {
+ SSL_DEBUG_MSG( 3, ( "received FALLBACK_SCSV" ) );
+
+ if( ssl->minor_ver < ssl->max_minor_ver )
+ {
+ SSL_DEBUG_MSG( 1, ( "inapropriate fallback" ) );
+
+ ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL,
+ SSL_ALERT_MSG_INAPROPRIATE_FALLBACK );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ break;
+ }
+ }
+#endif /* POLARSSL_SSL_FALLBACK_SCSV */
+
+ got_common_suite = 0;
+ ciphersuites = ssl->ciphersuite_list[ssl->minor_ver];
+ ciphersuite_info = NULL;
+#if defined(POLARSSL_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
+ for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
+ {
+ for( i = 0; ciphersuites[i] != 0; i++ )
+#else
+ for( i = 0; ciphersuites[i] != 0; i++ )
+ {
+ for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
+#endif
+ {
+ if( p[0] != 0 ||
+ p[1] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) ||
+ p[2] != ( ( ciphersuites[i] ) & 0xFF ) )
+ continue;
+
+ got_common_suite = 1;
+
+ if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
+ &ciphersuite_info ) ) != 0 )
+ return( ret );
+
+ if( ciphersuite_info != NULL )
+ goto have_ciphersuite_v2;
+ }
+ }
+
+ if( got_common_suite )
+ {
+ SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, "
+ "but none of them usable" ) );
+ return( POLARSSL_ERR_SSL_NO_USABLE_CIPHERSUITE );
+ }
+ else
+ {
+ SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) );
+ return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN );
+ }
+
+have_ciphersuite_v2:
+ SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) );
+
+ ssl->session_negotiate->ciphersuite = ciphersuites[i];
+ ssl->transform_negotiate->ciphersuite_info = ciphersuite_info;
+ ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info );
+
+ /*
+ * SSLv2 Client Hello relevant renegotiation security checks
+ */
+ if( ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION &&
+ ssl->allow_legacy_renegotiation == SSL_LEGACY_BREAK_HANDSHAKE )
+ {
+ SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
+
+ if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+ return( ret );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->in_left = 0;
+ ssl->state++;
+
+ SSL_DEBUG_MSG( 2, ( "<= parse client hello v2" ) );
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */
+
+static int ssl_parse_client_hello( ssl_context *ssl )
+{
+ int ret, got_common_suite;
+ unsigned int i, j;
+ size_t n;
+ unsigned int ciph_len, sess_len;
+ unsigned int comp_len;
+ unsigned int ext_len = 0;
+ unsigned char *buf, *p, *ext;
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ int renegotiation_info_seen = 0;
+#endif
+ int handshake_failure = 0;
+ const int *ciphersuites;
+ const ssl_ciphersuite_t *ciphersuite_info;
+
+ SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) );
+
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
+#endif
+ {
+ if( ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
+ return( ret );
+ }
+ }
+
+ buf = ssl->in_hdr;
+
+#if defined(POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
+ if( ( buf[0] & 0x80 ) != 0 )
+ return ssl_parse_client_hello_v2( ssl );
+#endif
+
+ SSL_DEBUG_BUF( 4, "record header", buf, 5 );
+
+ SSL_DEBUG_MSG( 3, ( "client hello v3, message type: %d",
+ buf[0] ) );
+ SSL_DEBUG_MSG( 3, ( "client hello v3, message len.: %d",
+ ( buf[3] << 8 ) | buf[4] ) );
+ SSL_DEBUG_MSG( 3, ( "client hello v3, protocol ver: [%d:%d]",
+ buf[1], buf[2] ) );
+
+ /*
+ * SSLv3/TLS Client Hello
+ *
+ * Record layer:
+ * 0 . 0 message type
+ * 1 . 2 protocol version
+ * 3 . 4 message length
+ */
+
+ /* According to RFC 5246 Appendix E.1, the version here is typically
+ * "{03,00}, the lowest version number supported by the client, [or] the
+ * value of ClientHello.client_version", so the only meaningful check here
+ * is the major version shouldn't be less than 3 */
+ if( buf[0] != SSL_MSG_HANDSHAKE ||
+ buf[1] < SSL_MAJOR_VERSION_3 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ n = ( buf[3] << 8 ) | buf[4];
+
+ if( n < 45 || n > SSL_MAX_CONTENT_LEN )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
+#endif
+ {
+ if( ( ret = ssl_fetch_input( ssl, 5 + n ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
+ return( ret );
+ }
+ }
+
+ buf = ssl->in_msg;
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
+ n = ssl->in_msglen;
+ else
+#endif
+ n = ssl->in_left - 5;
+
+ ssl->handshake->update_checksum( ssl, buf, n );
+
+ /*
+ * SSL layer:
+ * 0 . 0 handshake type
+ * 1 . 3 handshake length
+ * 4 . 5 protocol version
+ * 6 . 9 UNIX time()
+ * 10 . 37 random bytes
+ * 38 . 38 session id length
+ * 39 . 38+x session id
+ * 39+x . 40+x ciphersuitelist length
+ * 41+x . 40+y ciphersuitelist
+ * 41+y . 41+y compression alg length
+ * 42+y . 41+z compression algs
+ * .. . .. extensions
+ */
+ SSL_DEBUG_BUF( 4, "record contents", buf, n );
+
+ SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d",
+ buf[0] ) );
+ SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d",
+ ( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) );
+ SSL_DEBUG_MSG( 3, ( "client hello v3, max. version: [%d:%d]",
+ buf[4], buf[5] ) );
+
+ /*
+ * Check the handshake type and protocol version
+ */
+ if( buf[0] != SSL_HS_CLIENT_HELLO )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->major_ver = buf[4];
+ ssl->minor_ver = buf[5];
+
+ ssl->handshake->max_major_ver = ssl->major_ver;
+ ssl->handshake->max_minor_ver = ssl->minor_ver;
+
+ if( ssl->major_ver < ssl->min_major_ver ||
+ ssl->minor_ver < ssl->min_minor_ver )
+ {
+ SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum"
+ " [%d:%d] < [%d:%d]",
+ ssl->major_ver, ssl->minor_ver,
+ ssl->min_major_ver, ssl->min_minor_ver ) );
+
+ ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL,
+ SSL_ALERT_MSG_PROTOCOL_VERSION );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
+ }
+
+ if( ssl->major_ver > ssl->max_major_ver )
+ {
+ ssl->major_ver = ssl->max_major_ver;
+ ssl->minor_ver = ssl->max_minor_ver;
+ }
+ else if( ssl->minor_ver > ssl->max_minor_ver )
+ ssl->minor_ver = ssl->max_minor_ver;
+
+ memcpy( ssl->handshake->randbytes, buf + 6, 32 );
+
+ /*
+ * Check the handshake message length
+ */
+ if( buf[1] != 0 || n != (unsigned int) 4 + ( ( buf[2] << 8 ) | buf[3] ) )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /*
+ * Check the session length
+ */
+ sess_len = buf[38];
+
+ if( sess_len > 32 || sess_len > n - 42 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ ssl->session_negotiate->length = sess_len;
+ memset( ssl->session_negotiate->id, 0,
+ sizeof( ssl->session_negotiate->id ) );
+ memcpy( ssl->session_negotiate->id, buf + 39,
+ ssl->session_negotiate->length );
+
+ /*
+ * Check the ciphersuitelist length
+ */
+ ciph_len = ( buf[39 + sess_len] << 8 )
+ | ( buf[40 + sess_len] );
+
+ if( ciph_len < 2 || ( ciph_len % 2 ) != 0 || ciph_len > n - 42 - sess_len )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /*
+ * Check the compression algorithms length
+ */
+ comp_len = buf[41 + sess_len + ciph_len];
+
+ if( comp_len < 1 || comp_len > 16 ||
+ comp_len > n - 42 - sess_len - ciph_len )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /*
+ * Check the extension length
+ */
+ if( n > 42 + sess_len + ciph_len + comp_len )
+ {
+ ext_len = ( buf[42 + sess_len + ciph_len + comp_len] << 8 )
+ | ( buf[43 + sess_len + ciph_len + comp_len] );
+
+ if( ( ext_len > 0 && ext_len < 4 ) ||
+ n != 44 + sess_len + ciph_len + comp_len + ext_len )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ SSL_DEBUG_BUF( 3, "Ext", buf + 44 + sess_len + ciph_len + comp_len, ext_len);
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ }
+
+ ssl->session_negotiate->compression = SSL_COMPRESS_NULL;
+#if defined(POLARSSL_ZLIB_SUPPORT)
+ for( i = 0; i < comp_len; ++i )
+ {
+ if( buf[42 + sess_len + ciph_len + i] == SSL_COMPRESS_DEFLATE )
+ {
+ ssl->session_negotiate->compression = SSL_COMPRESS_DEFLATE;
+ break;
+ }
+ }
+#endif
+
+ SSL_DEBUG_BUF( 3, "client hello, random bytes",
+ buf + 6, 32 );
+ SSL_DEBUG_BUF( 3, "client hello, session id",
+ buf + 38, sess_len );
+ SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
+ buf + 41 + sess_len, ciph_len );
+ SSL_DEBUG_BUF( 3, "client hello, compression",
+ buf + 42 + sess_len + ciph_len, comp_len );
+
+ /*
+ * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
+ */
+ for( i = 0, p = buf + 41 + sess_len; i < ciph_len; i += 2, p += 2 )
+ {
+ if( p[0] == 0 && p[1] == SSL_EMPTY_RENEGOTIATION_INFO )
+ {
+ SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation == SSL_RENEGOTIATION )
+ {
+ SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV during renegotiation" ) );
+
+ if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+ return( ret );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ renegotiation_info_seen = 1;
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+ ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
+ break;
+ }
+ }
+
+#if defined(POLARSSL_SSL_FALLBACK_SCSV)
+ for( i = 0, p = buf + 41 + sess_len; i < ciph_len; i += 2, p += 2 )
+ {
+ if( p[0] == (unsigned char)( ( SSL_FALLBACK_SCSV >> 8 ) & 0xff ) &&
+ p[1] == (unsigned char)( ( SSL_FALLBACK_SCSV ) & 0xff ) )
+ {
+ SSL_DEBUG_MSG( 0, ( "received FALLBACK_SCSV" ) );
+
+ if( ssl->minor_ver < ssl->max_minor_ver )
+ {
+ SSL_DEBUG_MSG( 0, ( "inapropriate fallback" ) );
+
+ ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL,
+ SSL_ALERT_MSG_INAPROPRIATE_FALLBACK );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ break;
+ }
+ }
+#endif /* POLARSSL_SSL_FALLBACK_SCSV */
+
+ ext = buf + 44 + sess_len + ciph_len + comp_len;
+
+ while( ext_len )
+ {
+ unsigned int ext_id = ( ( ext[0] << 8 )
+ | ( ext[1] ) );
+ unsigned int ext_size = ( ( ext[2] << 8 )
+ | ( ext[3] ) );
+
+ if( ext_size + 4 > ext_len )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ switch( ext_id )
+ {
+#if defined(POLARSSL_SSL_SERVER_NAME_INDICATION)
+ case TLS_EXT_SERVERNAME:
+ SSL_DEBUG_MSG( 3, ( "found ServerName extension" ) );
+ if( ssl->f_sni == NULL )
+ break;
+
+ ret = ssl_parse_servername_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_SSL_SERVER_NAME_INDICATION */
+
+ case TLS_EXT_RENEGOTIATION_INFO:
+ SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ renegotiation_info_seen = 1;
+#endif
+
+ ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+
+#if defined(POLARSSL_SSL_PROTO_TLS1_2) && \
+ defined(POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED)
+ case TLS_EXT_SIG_ALG:
+ SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation == SSL_RENEGOTIATION )
+ break;
+#endif
+
+ ret = ssl_parse_signature_algorithms_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_SSL_PROTO_TLS1_2 &&
+ POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED */
+
+#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
+ case TLS_EXT_SUPPORTED_ELLIPTIC_CURVES:
+ SSL_DEBUG_MSG( 3, ( "found supported elliptic curves extension" ) );
+
+ ret = ssl_parse_supported_elliptic_curves( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+
+ case TLS_EXT_SUPPORTED_POINT_FORMATS:
+ SSL_DEBUG_MSG( 3, ( "found supported point formats extension" ) );
+ ssl->handshake->cli_exts |= TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT;
+
+ ret = ssl_parse_supported_point_formats( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */
+
+#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
+ case TLS_EXT_MAX_FRAGMENT_LENGTH:
+ SSL_DEBUG_MSG( 3, ( "found max fragment length extension" ) );
+
+ ret = ssl_parse_max_fragment_length_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */
+
+#if defined(POLARSSL_SSL_TRUNCATED_HMAC)
+ case TLS_EXT_TRUNCATED_HMAC:
+ SSL_DEBUG_MSG( 3, ( "found truncated hmac extension" ) );
+
+ ret = ssl_parse_truncated_hmac_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_SSL_TRUNCATED_HMAC */
+
+#if defined(POLARSSL_SSL_ENCRYPT_THEN_MAC)
+ case TLS_EXT_ENCRYPT_THEN_MAC:
+ SSL_DEBUG_MSG( 3, ( "found encrypt then mac extension" ) );
+
+ ret = ssl_parse_encrypt_then_mac_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_SSL_ENCRYPT_THEN_MAC */
+
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+ case TLS_EXT_EXTENDED_MASTER_SECRET:
+ SSL_DEBUG_MSG( 3, ( "found extended master secret extension" ) );
+
+ ret = ssl_parse_extended_ms_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
+#if defined(POLARSSL_SSL_SESSION_TICKETS)
+ case TLS_EXT_SESSION_TICKET:
+ SSL_DEBUG_MSG( 3, ( "found session ticket extension" ) );
+
+ ret = ssl_parse_session_ticket_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_SSL_SESSION_TICKETS */
+
+#if defined(POLARSSL_SSL_ALPN)
+ case TLS_EXT_ALPN:
+ SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
+
+ ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size );
+ if( ret != 0 )
+ return( ret );
+ break;
+#endif /* POLARSSL_SSL_SESSION_TICKETS */
+
+ default:
+ SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
+ ext_id ) );
+ }
+
+ ext_len -= 4 + ext_size;
+ ext += 4 + ext_size;
+
+ if( ext_len > 0 && ext_len < 4 )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+ }
+
+ /*
+ * Renegotiation security checks
+ */
+ if( ssl->secure_renegotiation != SSL_SECURE_RENEGOTIATION &&
+ ssl->allow_legacy_renegotiation == SSL_LEGACY_BREAK_HANDSHAKE )
+ {
+ SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
+ handshake_failure = 1;
+ }
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ else if( ssl->renegotiation == SSL_RENEGOTIATION &&
+ ssl->secure_renegotiation == SSL_SECURE_RENEGOTIATION &&
+ renegotiation_info_seen == 0 )
+ {
+ SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) );
+ handshake_failure = 1;
+ }
+ else if( ssl->renegotiation == SSL_RENEGOTIATION &&
+ ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION &&
+ ssl->allow_legacy_renegotiation == SSL_LEGACY_NO_RENEGOTIATION )
+ {
+ SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) );
+ handshake_failure = 1;
+ }
+ else if( ssl->renegotiation == SSL_RENEGOTIATION &&
+ ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION &&
+ renegotiation_info_seen == 1 )
+ {
+ SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
+ handshake_failure = 1;
+ }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+
+ if( handshake_failure == 1 )
+ {
+ if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+ return( ret );
+
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+ }
+
+ /*
+ * Search for a matching ciphersuite
+ * (At the end because we need information from the EC-based extensions
+ * and certificate from the SNI callback triggered by the SNI extension.)
+ */
+ got_common_suite = 0;
+ ciphersuites = ssl->ciphersuite_list[ssl->minor_ver];
+ ciphersuite_info = NULL;
+#if defined(POLARSSL_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
+ for( j = 0, p = buf + 41 + sess_len; j < ciph_len; j += 2, p += 2 )
+ {
+ for( i = 0; ciphersuites[i] != 0; i++ )
+#else
+ for( i = 0; ciphersuites[i] != 0; i++ )
+ {
+ for( j = 0, p = buf + 41 + sess_len; j < ciph_len; j += 2, p += 2 )
+#endif
+ {
+ if( p[0] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) ||
+ p[1] != ( ( ciphersuites[i] ) & 0xFF ) )
+ continue;
+
+ got_common_suite = 1;
+
+ if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
+ &ciphersuite_info ) ) != 0 )
+ return( ret );
+
+ if( ciphersuite_info != NULL )
+ goto have_ciphersuite;
+ }
+ }
+
+ if( got_common_suite )
+ {
+ SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, "
+ "but none of them usable" ) );
+ ssl_send_fatal_handshake_failure( ssl );
+ return( POLARSSL_ERR_SSL_NO_USABLE_CIPHERSUITE );
+ }
+ else
+ {
+ SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) );
+ ssl_send_fatal_handshake_failure( ssl );
+ return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN );
+ }
+
+have_ciphersuite:
+ SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) );
+
+ ssl->session_negotiate->ciphersuite = ciphersuites[i];
+ ssl->transform_negotiate->ciphersuite_info = ciphersuite_info;
+ ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info );
+
+ ssl->in_left = 0;
+ ssl->state++;
+
+ SSL_DEBUG_MSG( 2, ( "<= parse client hello" ) );
+
+ return( 0 );
+}
+
+#if defined(POLARSSL_SSL_TRUNCATED_HMAC)
+static void ssl_write_truncated_hmac_ext( ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+
+ if( ssl->session_negotiate->trunc_hmac == SSL_TRUNC_HMAC_DISABLED )
+ {
+ *olen = 0;
+ return;
+ }
+
+ SSL_DEBUG_MSG( 3, ( "server hello, adding truncated hmac extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC ) & 0xFF );
+
+ *p++ = 0x00;
+ *p++ = 0x00;
+
+ *olen = 4;
+}
+#endif /* POLARSSL_SSL_TRUNCATED_HMAC */
+
+#if defined(POLARSSL_SSL_ENCRYPT_THEN_MAC)
+static void ssl_write_encrypt_then_mac_ext( ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+ const ssl_ciphersuite_t *suite = NULL;
+ const cipher_info_t *cipher = NULL;
+
+ if( ssl->session_negotiate->encrypt_then_mac == SSL_EXTENDED_MS_DISABLED ||
+ ssl->minor_ver == SSL_MINOR_VERSION_0 )
+ {
+ *olen = 0;
+ return;
+ }
+
+ /*
+ * RFC 7366: "If a server receives an encrypt-then-MAC request extension
+ * from a client and then selects a stream or Authenticated Encryption
+ * with Associated Data (AEAD) ciphersuite, it MUST NOT send an
+ * encrypt-then-MAC response extension back to the client."
+ */
+ if( ( suite = ssl_ciphersuite_from_id(
+ ssl->session_negotiate->ciphersuite ) ) == NULL ||
+ ( cipher = cipher_info_from_type( suite->cipher ) ) == NULL ||
+ cipher->mode != POLARSSL_MODE_CBC )
+ {
+ *olen = 0;
+ return;
+ }
+
+ SSL_DEBUG_MSG( 3, ( "server hello, adding encrypt then mac extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_ENCRYPT_THEN_MAC >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_ENCRYPT_THEN_MAC ) & 0xFF );
+
+ *p++ = 0x00;
+ *p++ = 0x00;
+
+ *olen = 4;
+}
+#endif /* POLARSSL_SSL_ENCRYPT_THEN_MAC */
+
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+static void ssl_write_extended_ms_ext( ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+
+ if( ssl->handshake->extended_ms == SSL_EXTENDED_MS_DISABLED ||
+ ssl->minor_ver == SSL_MINOR_VERSION_0 )
+ {
+ *olen = 0;
+ return;
+ }
+
+ SSL_DEBUG_MSG( 3, ( "server hello, adding extended master secret "
+ "extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_EXTENDED_MASTER_SECRET ) & 0xFF );
+
+ *p++ = 0x00;
+ *p++ = 0x00;
+
+ *olen = 4;
+}
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
+#if defined(POLARSSL_SSL_SESSION_TICKETS)
+static void ssl_write_session_ticket_ext( ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+
+ if( ssl->handshake->new_session_ticket == 0 )
+ {
+ *olen = 0;
+ return;
+ }
+
+ SSL_DEBUG_MSG( 3, ( "server hello, adding session ticket extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_SESSION_TICKET ) & 0xFF );
+
+ *p++ = 0x00;
+ *p++ = 0x00;
+
+ *olen = 4;
+}
+#endif /* POLARSSL_SSL_SESSION_TICKETS */
+
+static void ssl_write_renegotiation_ext( ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+
+ if( ssl->secure_renegotiation != SSL_SECURE_RENEGOTIATION )
+ {
+ *olen = 0;
+ return;
+ }
+
+ SSL_DEBUG_MSG( 3, ( "server hello, secure renegotiation extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_RENEGOTIATION_INFO ) & 0xFF );
+
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
+ {
+ *p++ = 0x00;
+ *p++ = ( ssl->verify_data_len * 2 + 1 ) & 0xFF;
+ *p++ = ssl->verify_data_len * 2 & 0xFF;
+
+ memcpy( p, ssl->peer_verify_data, ssl->verify_data_len );
+ p += ssl->verify_data_len;
+ memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
+ p += ssl->verify_data_len;
+
+ *olen = 5 + ssl->verify_data_len * 2;
+ }
+ else
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+ {
+ *p++ = 0x00;
+ *p++ = 0x01;
+ *p++ = 0x00;
+
+ *olen = 5;
+ }
+}
+
+#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
+static void ssl_write_max_fragment_length_ext( ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+
+ if( ssl->session_negotiate->mfl_code == SSL_MAX_FRAG_LEN_NONE )
+ {
+ *olen = 0;
+ return;
+ }
+
+ SSL_DEBUG_MSG( 3, ( "server hello, max_fragment_length extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_MAX_FRAGMENT_LENGTH ) & 0xFF );
+
+ *p++ = 0x00;
+ *p++ = 1;
+
+ *p++ = ssl->session_negotiate->mfl_code;
+
+ *olen = 5;
+}
+#endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */
+
+#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
+static void ssl_write_supported_point_formats_ext( ssl_context *ssl,
+ unsigned char *buf,
+ size_t *olen )
+{
+ unsigned char *p = buf;
+ ((void) ssl);
+
+ if( ( ssl->handshake->cli_exts &
+ TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT ) == 0 )
+ {
+ *olen = 0;
+ return;
+ }
+
+ SSL_DEBUG_MSG( 3, ( "server hello, supported_point_formats extension" ) );
+
+ *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF );
+
+ *p++ = 0x00;
+ *p++ = 2;
+
+ *p++ = 1;
+ *p++ = POLARSSL_ECP_PF_UNCOMPRESSED;
+
+ *olen = 6;
+}
+#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */
+
+#if defined(POLARSSL_SSL_ALPN )
+static void ssl_write_alpn_ext( ssl_context *ssl,
+ unsigned char *buf, size_t *olen )
+{
+ if( ssl->alpn_chosen == NULL )
+ {
+ *olen = 0;
+ return;
+ }
+
+ SSL_DEBUG_MSG( 3, ( "server hello, adding alpn extension" ) );
+
+ /*
+ * 0 . 1 ext identifier
+ * 2 . 3 ext length
+ * 4 . 5 protocol list length
+ * 6 . 6 protocol name length
+ * 7 . 7+n protocol name
+ */
+ buf[0] = (unsigned char)( ( TLS_EXT_ALPN >> 8 ) & 0xFF );
+ buf[1] = (unsigned char)( ( TLS_EXT_ALPN ) & 0xFF );
+
+ *olen = 7 + strlen( ssl->alpn_chosen );
+
+ buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF );
+ buf[3] = (unsigned char)( ( ( *olen - 4 ) ) & 0xFF );
+
+ buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF );
+ buf[5] = (unsigned char)( ( ( *olen - 6 ) ) & 0xFF );
+
+ buf[6] = (unsigned char)( ( ( *olen - 7 ) ) & 0xFF );
+
+ memcpy( buf + 7, ssl->alpn_chosen, *olen - 7 );
+}
+#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */
+
+static int ssl_write_server_hello( ssl_context *ssl )
+{
+#if defined(POLARSSL_HAVE_TIME)
+ time_t t;
+#endif
+ int ret;
+ size_t olen, ext_len = 0, n;
+ unsigned char *buf, *p;
+
+ SSL_DEBUG_MSG( 2, ( "=> write server hello" ) );
+
+ if( ssl->f_rng == NULL )
+ {
+ SSL_DEBUG_MSG( 1, ( "no RNG provided") );
+ return( POLARSSL_ERR_SSL_NO_RNG );
+ }
+
+ /*
+ * 0 . 0 handshake type
+ * 1 . 3 handshake length
+ * 4 . 5 protocol version
+ * 6 . 9 UNIX time()
+ * 10 . 37 random bytes
+ */
+ buf = ssl->out_msg;
+ p = buf + 4;
+
+ *p++ = (unsigned char) ssl->major_ver;
+ *p++ = (unsigned char) ssl->minor_ver;
+
+ SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]",
+ buf[4], buf[5] ) );
+
+#if defined(POLARSSL_HAVE_TIME)
+ t = time( NULL );
+ *p++ = (unsigned char)( t >> 24 );
+ *p++ = (unsigned char)( t >> 16 );
+ *p++ = (unsigned char)( t >> 8 );
+ *p++ = (unsigned char)( t );
+
+ SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) );
+#else
+ if( ( ret = ssl->f_rng( ssl->p_rng, p, 4 ) ) != 0 )
+ return( ret );
+
+ p += 4;
+#endif /* POLARSSL_HAVE_TIME */
+
+ if( ( ret = ssl->f_rng( ssl->p_rng, p, 28 ) ) != 0 )
+ return( ret );
+
+ p += 28;
+
+ memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 );
+
+ SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 );
+
+ /*
+ * Resume is 0 by default, see ssl_handshake_init().
+ * It may be already set to 1 by ssl_parse_session_ticket_ext().
+ * If not, try looking up session ID in our cache.
+ */
+ if( ssl->handshake->resume == 0 &&
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+ ssl->renegotiation == SSL_INITIAL_HANDSHAKE &&
+#endif
+ ssl->session_negotiate->length != 0 &&
+ ssl->f_get_cache != NULL &&
+ ssl->f_get_cache( ssl->p_get_cache, ssl->session_negotiate ) == 0 )
+ {
+ SSL_DEBUG_MSG( 3, ( "session successfully restored from cache" ) );
+ ssl->handshake->resume = 1;
+ }
+
+ if( ssl->handshake->resume == 0 )
+ {
+ /*
+ * New session, create a new session id,
+ * unless we're about to issue a session ticket
+ */
+ ssl->state++;
+
+#if defined(POLARSSL_HAVE_TIME)
+ ssl->session_negotiate->start = time( NULL );
+#endif
+
+#if defined(POLARSSL_SSL_SESSION_TICKETS)
+ if( ssl->handshake->new_session_ticket != 0 )
+ {
+ ssl->session_negotiate->length = n = 0;
+ memset( ssl->session_negotiate->id, 0, 32 );
+ }
+ else
+#endif /* POLARSSL_SSL_SESSION_TICKETS */
+ {
+ ssl->session_negotiate->length = n = 32;
+ if( ( ret = ssl->f_rng( ssl->p_rng, ssl->session_negotiate->id,
+ n ) ) != 0 )
+ return( ret );
+ }
+ }
+ else
+ {
+ /*
+ * Resuming a session
+ */
+ n = ssl->session_negotiate->length;
+ ssl->state = SSL_SERVER_CHANGE_CIPHER_SPEC;
+
+ if( ( ret = ssl_derive_keys( ssl ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_derive_keys", ret );
+ return( ret );
+ }
+ }
+
+ /*
+ * 38 . 38 session id length
+ * 39 . 38+n session id
+ * 39+n . 40+n chosen ciphersuite
+ * 41+n . 41+n chosen compression alg.
+ * 42+n . 43+n extensions length
+ * 44+n . 43+n+m extensions
+ */
+ *p++ = (unsigned char) ssl->session_negotiate->length;
+ memcpy( p, ssl->session_negotiate->id, ssl->session_negotiate->length );
+ p += ssl->session_negotiate->length;
+
+ SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
+ SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n );
+ SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
+ ssl->handshake->resume ? "a" : "no" ) );
+
+ *p++ = (unsigned char)( ssl->session_negotiate->ciphersuite >> 8 );
+ *p++ = (unsigned char)( ssl->session_negotiate->ciphersuite );
+ *p++ = (unsigned char)( ssl->session_negotiate->compression );
+
+ SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %s",
+ ssl_get_ciphersuite_name( ssl->session_negotiate->ciphersuite ) ) );
+ SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: 0x%02X",
+ ssl->session_negotiate->compression ) );
+
+ /*
+ * First write extensions, then the total length
+ */
+ ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+
+#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
+ ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(POLARSSL_SSL_TRUNCATED_HMAC)
+ ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(POLARSSL_SSL_ENCRYPT_THEN_MAC)
+ ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+ ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(POLARSSL_SSL_SESSION_TICKETS)
+ ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C)
+ ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+#if defined(POLARSSL_SSL_ALPN)
+ ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
+ ext_len += olen;
+#endif
+
+ SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %d", ext_len ) );
+
+ if( ext_len > 0 )
+ {
+ *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( ext_len ) & 0xFF );
+ p += ext_len;
+ }
+
+ ssl->out_msglen = p - buf;
+ ssl->out_msgtype = SSL_MSG_HANDSHAKE;
+ ssl->out_msg[0] = SSL_HS_SERVER_HELLO;
+
+ ret = ssl_write_record( ssl );
+
+ SSL_DEBUG_MSG( 2, ( "<= write server hello" ) );
+
+ return( ret );
+}
+
+#if !defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) && \
+ !defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
+ !defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
+ !defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+static int ssl_write_certificate_request( ssl_context *ssl )
+{
+ const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
+
+ SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
+
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
+ {
+ SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
+ ssl->state++;
+ return( 0 );
+ }
+
+ SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( POLARSSL_ERR_SSL_INTERNAL_ERROR );
+}
+#else
+static int ssl_write_certificate_request( ssl_context *ssl )
+{
+ int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
+ const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
+ size_t dn_size, total_dn_size; /* excluding length bytes */
+ size_t ct_len, sa_len; /* including length bytes */
+ unsigned char *buf, *p;
+ const x509_crt *crt;
+
+ SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
+
+ ssl->state++;
+
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ||
+ ssl->authmode == SSL_VERIFY_NONE )
+ {
+ SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
+ return( 0 );
+ }
+
+ /*
+ * 0 . 0 handshake type
+ * 1 . 3 handshake length
+ * 4 . 4 cert type count
+ * 5 .. m-1 cert types
+ * m .. m+1 sig alg length (TLS 1.2 only)
+ * m+1 .. n-1 SignatureAndHashAlgorithms (TLS 1.2 only)
+ * n .. n+1 length of all DNs
+ * n+2 .. n+3 length of DN 1
+ * n+4 .. ... Distinguished Name #1
+ * ... .. ... length of DN 2, etc.
+ */
+ buf = ssl->out_msg;
+ p = buf + 4;
+
+ /*
+ * Supported certificate types
+ *
+ * ClientCertificateType certificate_types<1..2^8-1>;
+ * enum { (255) } ClientCertificateType;
+ */
+ ct_len = 0;
+
+#if defined(POLARSSL_RSA_C)
+ p[1 + ct_len++] = SSL_CERT_TYPE_RSA_SIGN;
+#endif
+#if defined(POLARSSL_ECDSA_C)
+ p[1 + ct_len++] = SSL_CERT_TYPE_ECDSA_SIGN;
+#endif
+
+ p[0] = (unsigned char) ct_len++;
+ p += ct_len;
+
+ sa_len = 0;
+#if defined(POLARSSL_SSL_PROTO_TLS1_2)
+ /*
+ * Add signature_algorithms for verify (TLS 1.2)
+ *
+ * SignatureAndHashAlgorithm supported_signature_algorithms<2..2^16-2>;
+ *
+ * struct {
+ * HashAlgorithm hash;
+ * SignatureAlgorithm signature;
+ * } SignatureAndHashAlgorithm;
+ *
+ * enum { (255) } HashAlgorithm;
+ * enum { (255) } SignatureAlgorithm;
+ */
+ if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
+ {
+ /*
+ * Only use current running hash algorithm that is already required
+ * for requested ciphersuite.
+ */
+ ssl->handshake->verify_sig_alg = SSL_HASH_SHA256;
+
+ if( ssl->transform_negotiate->ciphersuite_info->mac ==
+ POLARSSL_MD_SHA384 )
+ {
+ ssl->handshake->verify_sig_alg = SSL_HASH_SHA384;
+ }
+
+ /*
+ * Supported signature algorithms
+ */
+#if defined(POLARSSL_RSA_C)
+ p[2 + sa_len++] = ssl->handshake->verify_sig_alg;
+ p[2 + sa_len++] = SSL_SIG_RSA;
+#endif
+#if defined(POLARSSL_ECDSA_C)
+ p[2 + sa_len++] = ssl->handshake->verify_sig_alg;
+ p[2 + sa_len++] = SSL_SIG_ECDSA;
+#endif
+
+ p[0] = (unsigned char)( sa_len >> 8 );
+ p[1] = (unsigned char)( sa_len );
+ sa_len += 2;
+ p += sa_len;
+ }
+#endif /* POLARSSL_SSL_PROTO_TLS1_2 */
+
+ /*
+ * DistinguishedName certificate_authorities<0..2^16-1>;
+ * opaque DistinguishedName<1..2^16-1>;
+ */
+ p += 2;
+ crt = ssl->ca_chain;
+
+ total_dn_size = 0;
+ while( crt != NULL && crt->version != 0 )
+ {
+ if( p - buf > 4096 )
+ break;
+
+ dn_size = crt->subject_raw.len;
+ *p++ = (unsigned char)( dn_size >> 8 );
+ *p++ = (unsigned char)( dn_size );
+ memcpy( p, crt->subject_raw.p, dn_size );
+ p += dn_size;
+
+ SSL_DEBUG_BUF( 3, "requested DN", p, dn_size );
+
+ total_dn_size += 2 + dn_size;
+ crt = crt->next;
+ }
+
+ ssl->out_msglen = p - buf;
+ ssl->out_msgtype = SSL_MSG_HANDSHAKE;
+ ssl->out_msg[0] = SSL_HS_CERTIFICATE_REQUEST;
+ ssl->out_msg[4 + ct_len + sa_len] = (unsigned char)( total_dn_size >> 8 );
+ ssl->out_msg[5 + ct_len + sa_len] = (unsigned char)( total_dn_size );
+
+ ret = ssl_write_record( ssl );
+
+ SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) );
+
+ return( ret );
+}
+#endif /* !POLARSSL_KEY_EXCHANGE_RSA_ENABLED &&
+ !POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED &&
+ !POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
+ !POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+
+#if defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+static int ssl_get_ecdh_params_from_cert( ssl_context *ssl )
+{
+ int ret;
+
+ if( ! pk_can_do( ssl_own_key( ssl ), POLARSSL_PK_ECKEY ) )
+ {
+ SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
+ return( POLARSSL_ERR_SSL_PK_TYPE_MISMATCH );
+ }
+
+ if( ( ret = ecdh_get_params( &ssl->handshake->ecdh_ctx,
+ pk_ec( *ssl_own_key( ssl ) ),
+ POLARSSL_ECDH_OURS ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ecdh_get_params" ), ret );
+ return( ret );
+ }
+
+ return( 0 );
+}
+#endif /* POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
+ POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
+
+static int ssl_write_server_key_exchange( ssl_context *ssl )
+{
+ int ret;
+ size_t n = 0;
+ const ssl_ciphersuite_t *ciphersuite_info =
+ ssl->transform_negotiate->ciphersuite_info;
+
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+ unsigned char *p = ssl->out_msg + 4;
+ unsigned char *dig_signed = p;
+ size_t dig_signed_len = 0, len;
+ ((void) dig_signed);
+ ((void) dig_signed_len);
+#endif
+
+ SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) );
+
+#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK )
+ {
+ SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) );
+ ssl->state++;
+ return( 0 );
+ }
+#endif
+
+#if defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA )
+ {
+ ssl_get_ecdh_params_from_cert( ssl );
+
+ SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) );
+ ssl->state++;
+ return( 0 );
+ }
+#endif
+
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
+ {
+ /* TODO: Support identity hints */
+ *(p++) = 0x00;
+ *(p++) = 0x00;
+
+ n += 2;
+ }
+#endif /* POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
+
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
+ {
+ /*
+ * Ephemeral DH parameters:
+ *
+ * struct {
+ * opaque dh_p<1..2^16-1>;
+ * opaque dh_g<1..2^16-1>;
+ * opaque dh_Ys<1..2^16-1>;
+ * } ServerDHParams;
+ */
+ if( ( ret = mpi_copy( &ssl->handshake->dhm_ctx.P, &ssl->dhm_P ) ) != 0 ||
+ ( ret = mpi_copy( &ssl->handshake->dhm_ctx.G, &ssl->dhm_G ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "mpi_copy", ret );
+ return( ret );
+ }
+
+ if( ( ret = dhm_make_params( &ssl->handshake->dhm_ctx,
+ (int) mpi_size( &ssl->handshake->dhm_ctx.P ),
+ p, &len, ssl->f_rng, ssl->p_rng ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "dhm_make_params", ret );
+ return( ret );
+ }
+
+ dig_signed = p;
+ dig_signed_len = len;
+
+ p += len;
+ n += len;
+
+ SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X );
+ SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
+ SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
+ SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
+ }
+#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
+
+#if defined(POLARSSL_KEY_EXCHANGE__SOME__ECDHE_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
+ {
+ /*
+ * Ephemeral ECDH parameters:
+ *
+ * struct {
+ * ECParameters curve_params;
+ * ECPoint public;
+ * } ServerECDHParams;
+ */
+ const ecp_curve_info **curve = NULL;
+#if defined(POLARSSL_SSL_SET_CURVES)
+ const ecp_group_id *gid;
+
+ /* Match our preference list against the offered curves */
+ for( gid = ssl->curve_list; *gid != POLARSSL_ECP_DP_NONE; gid++ )
+ for( curve = ssl->handshake->curves; *curve != NULL; curve++ )
+ if( (*curve)->grp_id == *gid )
+ goto curve_matching_done;
+
+curve_matching_done:
+#else
+ curve = ssl->handshake->curves;
+#endif
+
+ if( *curve == NULL )
+ {
+ SSL_DEBUG_MSG( 1, ( "no matching curve for ECDHE" ) );
+ return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN );
+ }
+
+ SSL_DEBUG_MSG( 2, ( "ECDHE curve: %s", (*curve)->name ) );
+
+ if( ( ret = ecp_use_known_dp( &ssl->handshake->ecdh_ctx.grp,
+ (*curve)->grp_id ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecp_use_known_dp", ret );
+ return( ret );
+ }
+
+ if( ( ret = ecdh_make_params( &ssl->handshake->ecdh_ctx, &len,
+ p, SSL_MAX_CONTENT_LEN - n,
+ ssl->f_rng, ssl->p_rng ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_make_params", ret );
+ return( ret );
+ }
+
+ dig_signed = p;
+ dig_signed_len = len;
+
+ p += len;
+ n += len;
+
+ SSL_DEBUG_ECP( 3, "ECDH: Q ", &ssl->handshake->ecdh_ctx.Q );
+ }
+#endif /* POLARSSL_KEY_EXCHANGE__SOME__ECDHE_ENABLED */
+
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA )
+ {
+ size_t signature_len = 0;
+ unsigned int hashlen = 0;
+ unsigned char hash[64];
+ md_type_t md_alg = POLARSSL_MD_NONE;
+
+ /*
+ * Choose hash algorithm. NONE means MD5 + SHA1 here.
+ */
+#if defined(POLARSSL_SSL_PROTO_TLS1_2)
+ if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
+ {
+ md_alg = ssl_md_alg_from_hash( ssl->handshake->sig_alg );
+
+ if( md_alg == POLARSSL_MD_NONE )
+ {
+ SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( POLARSSL_ERR_SSL_INTERNAL_ERROR );
+ }
+ }
+ else
+#endif /* POLARSSL_SSL_PROTO_TLS1_2 */
+#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \
+ defined(POLARSSL_SSL_PROTO_TLS1_1)
+ if( ciphersuite_info->key_exchange ==
+ POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA )
+ {
+ md_alg = POLARSSL_MD_SHA1;
+ }
+ else
+#endif
+ {
+ md_alg = POLARSSL_MD_NONE;
+ }
+
+ /*
+ * Compute the hash to be signed
+ */
+#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \
+ defined(POLARSSL_SSL_PROTO_TLS1_1)
+ if( md_alg == POLARSSL_MD_NONE )
+ {
+ md5_context md5;
+ sha1_context sha1;
+
+ md5_init( &md5 );
+ sha1_init( &sha1 );
+
+ /*
+ * digitally-signed struct {
+ * opaque md5_hash[16];
+ * opaque sha_hash[20];
+ * };
+ *
+ * md5_hash
+ * MD5(ClientHello.random + ServerHello.random
+ * + ServerParams);
+ * sha_hash
+ * SHA(ClientHello.random + ServerHello.random
+ * + ServerParams);
+ */
+ md5_starts( &md5 );
+ md5_update( &md5, ssl->handshake->randbytes, 64 );
+ md5_update( &md5, dig_signed, dig_signed_len );
+ md5_finish( &md5, hash );
+
+ sha1_starts( &sha1 );
+ sha1_update( &sha1, ssl->handshake->randbytes, 64 );
+ sha1_update( &sha1, dig_signed, dig_signed_len );
+ sha1_finish( &sha1, hash + 16 );
+
+ hashlen = 36;
+
+ md5_free( &md5 );
+ sha1_free( &sha1 );
+ }
+ else
+#endif /* POLARSSL_SSL_PROTO_SSL3 || POLARSSL_SSL_PROTO_TLS1 || \
+ POLARSSL_SSL_PROTO_TLS1_1 */
+#if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \
+ defined(POLARSSL_SSL_PROTO_TLS1_2)
+ if( md_alg != POLARSSL_MD_NONE )
+ {
+ md_context_t ctx;
+ const md_info_t *md_info = md_info_from_type( md_alg );
+
+ md_init( &ctx );
+
+ /* Info from md_alg will be used instead */
+ hashlen = 0;
+
+ /*
+ * digitally-signed struct {
+ * opaque client_random[32];
+ * opaque server_random[32];
+ * ServerDHParams params;
+ * };
+ */
+ if( ( ret = md_init_ctx( &ctx, md_info ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "md_init_ctx", ret );
+ return( ret );
+ }
+
+ md_starts( &ctx );
+ md_update( &ctx, ssl->handshake->randbytes, 64 );
+ md_update( &ctx, dig_signed, dig_signed_len );
+ md_finish( &ctx, hash );
+ md_free( &ctx );
+ }
+ else
+#endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 || \
+ POLARSSL_SSL_PROTO_TLS1_2 */
+ {
+ SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( POLARSSL_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen != 0 ? hashlen :
+ (unsigned int) ( md_info_from_type( md_alg ) )->size );
+
+ /*
+ * Make the signature
+ */
+ if( ssl_own_key( ssl ) == NULL )
+ {
+ SSL_DEBUG_MSG( 1, ( "got no private key" ) );
+ return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED );
+ }
+
+#if defined(POLARSSL_SSL_PROTO_TLS1_2)
+ if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
+ {
+ *(p++) = ssl->handshake->sig_alg;
+ *(p++) = ssl_sig_from_pk( ssl_own_key( ssl ) );
+
+ n += 2;
+ }
+#endif /* POLARSSL_SSL_PROTO_TLS1_2 */
+
+ if( ( ret = pk_sign( ssl_own_key( ssl ), md_alg, hash, hashlen,
+ p + 2 , &signature_len,
+ ssl->f_rng, ssl->p_rng ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "pk_sign", ret );
+ return( ret );
+ }
+
+ *(p++) = (unsigned char)( signature_len >> 8 );
+ *(p++) = (unsigned char)( signature_len );
+ n += 2;
+
+ SSL_DEBUG_BUF( 3, "my signature", p, signature_len );
+
+ p += signature_len;
+ n += signature_len;
+ }
+#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) ||
+ POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+
+ ssl->out_msglen = 4 + n;
+ ssl->out_msgtype = SSL_MSG_HANDSHAKE;
+ ssl->out_msg[0] = SSL_HS_SERVER_KEY_EXCHANGE;
+
+ ssl->state++;
+
+ if( ( ret = ssl_write_record( ssl ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_write_record", ret );
+ return( ret );
+ }
+
+ SSL_DEBUG_MSG( 2, ( "<= write server key exchange" ) );
+
+ return( 0 );
+}
+
+static int ssl_write_server_hello_done( ssl_context *ssl )
+{
+ int ret;
+
+ SSL_DEBUG_MSG( 2, ( "=> write server hello done" ) );
+
+ ssl->out_msglen = 4;
+ ssl->out_msgtype = SSL_MSG_HANDSHAKE;
+ ssl->out_msg[0] = SSL_HS_SERVER_HELLO_DONE;
+
+ ssl->state++;
+
+ if( ( ret = ssl_write_record( ssl ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_write_record", ret );
+ return( ret );
+ }
+
+ SSL_DEBUG_MSG( 2, ( "<= write server hello done" ) );
+
+ return( 0 );
+}
+
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
+static int ssl_parse_client_dh_public( ssl_context *ssl, unsigned char **p,
+ const unsigned char *end )
+{
+ int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
+ size_t n;
+
+ /*
+ * Receive G^Y mod P, premaster = (G^Y)^X mod P
+ */
+ if( *p + 2 > end )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ n = ( (*p)[0] << 8 ) | (*p)[1];
+ *p += 2;
+
+ if( *p + n > end )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ if( ( ret = dhm_read_public( &ssl->handshake->dhm_ctx, *p, n ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "dhm_read_public", ret );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
+ }
+
+ *p += n;
+
+ SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
+
+ return( ret );
+}
+#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
+
+#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)
+static int ssl_parse_encrypted_pms( ssl_context *ssl,
+ const unsigned char *p,
+ const unsigned char *end,
+ size_t pms_offset )
+{
+ int ret;
+ size_t len = pk_get_len( ssl_own_key( ssl ) );
+ unsigned char *pms = ssl->handshake->premaster + pms_offset;
+ unsigned char fake_pms[48], peer_pms[48];
+ unsigned char mask;
+ size_t i, diff, peer_pmslen;
+
+ if( ! pk_can_do( ssl_own_key( ssl ), POLARSSL_PK_RSA ) )
+ {
+ SSL_DEBUG_MSG( 1, ( "got no RSA private key" ) );
+ return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED );
+ }
+
+ /*
+ * Decrypt the premaster using own private RSA key
+ */
+#if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \
+ defined(POLARSSL_SSL_PROTO_TLS1_2)
+ if( ssl->minor_ver != SSL_MINOR_VERSION_0 )
+ {
+ if( *p++ != ( ( len >> 8 ) & 0xFF ) ||
+ *p++ != ( ( len ) & 0xFF ) )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+ }
+#endif
+
+ if( p + len != end )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ /*
+ * Protection against Bleichenbacher's attack: invalid PKCS#1 v1.5 padding
+ * must not cause the connection to end immediately; instead, send a
+ * bad_record_mac later in the handshake.
+ * Also, avoid data-dependant branches here to protect against
+ * timing-based variants.
+ */
+ ret = ssl->f_rng( ssl->p_rng, fake_pms, sizeof( fake_pms ) );
+ if( ret != 0 )
+ return( ret );
+
+ ret = pk_decrypt( ssl_own_key( ssl ), p, len,
+ peer_pms, &peer_pmslen,
+ sizeof( peer_pms ),
+ ssl->f_rng, ssl->p_rng );
+
+ diff = (size_t) ret;
+ diff |= peer_pmslen ^ 48;
+ diff |= peer_pms[0] ^ ssl->handshake->max_major_ver;
+ diff |= peer_pms[1] ^ ssl->handshake->max_minor_ver;
+
+#if defined(POLARSSL_SSL_DEBUG_ALL)
+ if( diff != 0 )
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+#endif
+
+ if( sizeof( ssl->handshake->premaster ) < pms_offset ||
+ sizeof( ssl->handshake->premaster ) - pms_offset < 48 )
+ {
+ SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( POLARSSL_ERR_SSL_INTERNAL_ERROR );
+ }
+ ssl->handshake->pmslen = 48;
+
+ mask = ( diff | - diff ) >> ( sizeof( size_t ) * 8 - 1 );
+ mask = (unsigned char)( - ( ret != 0 ) ); /* mask = diff ? 0xff : 0x00 */
+ for( i = 0; i < ssl->handshake->pmslen; i++ )
+ pms[i] = ( mask & fake_pms[i] ) | ( (~mask) & peer_pms[i] );
+
+ return( 0 );
+}
+#endif /* POLARSSL_KEY_EXCHANGE_RSA_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED */
+
+#if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED)
+static int ssl_parse_client_psk_identity( ssl_context *ssl, unsigned char **p,
+ const unsigned char *end )
+{
+ int ret = 0;
+ size_t n;
+
+ if( ssl->f_psk == NULL &&
+ ( ssl->psk == NULL || ssl->psk_identity == NULL ||
+ ssl->psk_identity_len == 0 || ssl->psk_len == 0 ) )
+ {
+ SSL_DEBUG_MSG( 1, ( "got no pre-shared key" ) );
+ return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED );
+ }
+
+ /*
+ * Receive client pre-shared key identity name
+ */
+ if( *p + 2 > end )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ n = ( (*p)[0] << 8 ) | (*p)[1];
+ *p += 2;
+
+ if( n < 1 || n > 65535 || *p + n > end )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ if( ssl->f_psk != NULL )
+ {
+ if( ssl->f_psk( ssl->p_psk, ssl, *p, n ) != 0 )
+ ret = POLARSSL_ERR_SSL_UNKNOWN_IDENTITY;
+ }
+ else
+ {
+ /* Identity is not a big secret since clients send it in the clear,
+ * but treat it carefully anyway, just in case */
+ if( n != ssl->psk_identity_len ||
+ safer_memcmp( ssl->psk_identity, *p, n ) != 0 )
+ {
+ ret = POLARSSL_ERR_SSL_UNKNOWN_IDENTITY;
+ }
+ }
+
+ if( ret == POLARSSL_ERR_SSL_UNKNOWN_IDENTITY )
+ {
+ SSL_DEBUG_BUF( 3, "Unknown PSK identity", *p, n );
+ if( ( ret = ssl_send_alert_message( ssl,
+ SSL_ALERT_LEVEL_FATAL,
+ SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ return( POLARSSL_ERR_SSL_UNKNOWN_IDENTITY );
+ }
+
+ *p += n;
+
+ return( 0 );
+}
+#endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */
+
+static int ssl_parse_client_key_exchange( ssl_context *ssl )
+{
+ int ret;
+ const ssl_ciphersuite_t *ciphersuite_info;
+
+ ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
+
+ SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) );
+
+ if( ( ret = ssl_read_record( ssl ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_read_record", ret );
+ return( ret );
+ }
+
+ if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ if( ssl->in_msg[0] != SSL_HS_CLIENT_KEY_EXCHANGE )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA )
+ {
+ unsigned char *p = ssl->in_msg + 4;
+ unsigned char *end = ssl->in_msg + ssl->in_hslen;
+
+ if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ssl_parse_client_dh_public" ), ret );
+ return( ret );
+ }
+
+ if( p != end )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ ssl->handshake->pmslen = POLARSSL_PREMASTER_SIZE;
+
+ if( ( ret = dhm_calc_secret( &ssl->handshake->dhm_ctx,
+ ssl->handshake->premaster,
+ &ssl->handshake->pmslen,
+ ssl->f_rng, ssl->p_rng ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "dhm_calc_secret", ret );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS );
+ }
+
+ SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K );
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED */
+#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
+ defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA )
+ {
+ if( ( ret = ecdh_read_public( &ssl->handshake->ecdh_ctx,
+ ssl->in_msg + 4, ssl->in_hslen - 4 ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_read_public", ret );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
+ }
+
+ SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
+
+ if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
+ &ssl->handshake->pmslen,
+ ssl->handshake->premaster,
+ POLARSSL_MPI_MAX_SIZE,
+ ssl->f_rng, ssl->p_rng ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_calc_secret", ret );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS );
+ }
+
+ SSL_DEBUG_MPI( 3, "ECDH: z ", &ssl->handshake->ecdh_ctx.z );
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
+ POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
+#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK )
+ {
+ unsigned char *p = ssl->in_msg + 4;
+ unsigned char *end = ssl->in_msg + ssl->in_hslen;
+
+ if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
+ return( ret );
+ }
+
+ if( p != end )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ if( ( ret = ssl_psk_derive_premaster( ssl,
+ ciphersuite_info->key_exchange ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_psk_derive_premaster", ret );
+ return( ret );
+ }
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_PSK_ENABLED */
+#if defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK )
+ {
+ unsigned char *p = ssl->in_msg + 4;
+ unsigned char *end = ssl->in_msg + ssl->in_hslen;
+
+ if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
+ return( ret );
+ }
+
+ if( ( ret = ssl_parse_encrypted_pms( ssl, p, end, 2 ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ssl_parse_encrypted_pms" ), ret );
+ return( ret );
+ }
+
+ if( ( ret = ssl_psk_derive_premaster( ssl,
+ ciphersuite_info->key_exchange ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_psk_derive_premaster", ret );
+ return( ret );
+ }
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED */
+#if defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
+ {
+ unsigned char *p = ssl->in_msg + 4;
+ unsigned char *end = ssl->in_msg + ssl->in_hslen;
+
+ if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
+ return( ret );
+ }
+ if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ssl_parse_client_dh_public" ), ret );
+ return( ret );
+ }
+
+ if( p != end )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
+ }
+
+ if( ( ret = ssl_psk_derive_premaster( ssl,
+ ciphersuite_info->key_exchange ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_psk_derive_premaster", ret );
+ return( ret );
+ }
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */
+#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
+ {
+ unsigned char *p = ssl->in_msg + 4;
+ unsigned char *end = ssl->in_msg + ssl->in_hslen;
+
+ if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
+ return( ret );
+ }
+
+ if( ( ret = ecdh_read_public( &ssl->handshake->ecdh_ctx,
+ p, end - p ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ecdh_read_public", ret );
+ return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
+ }
+
+ SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
+
+ if( ( ret = ssl_psk_derive_premaster( ssl,
+ ciphersuite_info->key_exchange ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_psk_derive_premaster", ret );
+ return( ret );
+ }
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
+#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED)
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA )
+ {
+ if( ( ret = ssl_parse_encrypted_pms( ssl,
+ ssl->in_msg + 4,
+ ssl->in_msg + ssl->in_hslen,
+ 0 ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, ( "ssl_parse_parse_encrypted_pms_secret" ), ret );
+ return( ret );
+ }
+ }
+ else
+#endif /* POLARSSL_KEY_EXCHANGE_RSA_ENABLED */
+ {
+ SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( POLARSSL_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ if( ( ret = ssl_derive_keys( ssl ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_derive_keys", ret );
+ return( ret );
+ }
+
+ ssl->state++;
+
+ SSL_DEBUG_MSG( 2, ( "<= parse client key exchange" ) );
+
+ return( 0 );
+}
+
+#if !defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) && \
+ !defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) && \
+ !defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
+ !defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+static int ssl_parse_certificate_verify( ssl_context *ssl )
+{
+ const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
+
+ SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
+
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
+ {
+ SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
+ ssl->state++;
+ return( 0 );
+ }
+
+ SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( POLARSSL_ERR_SSL_INTERNAL_ERROR );
+}
+#else
+static int ssl_parse_certificate_verify( ssl_context *ssl )
+{
+ int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE;
+ size_t sa_len, sig_len;
+ unsigned char hash[48];
+ unsigned char *hash_start = hash;
+ size_t hashlen;
+#if defined(POLARSSL_SSL_PROTO_TLS1_2)
+ pk_type_t pk_alg;
+#endif
+ md_type_t md_alg;
+ const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
+
+ SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
+
+ if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ||
+ ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
+ {
+ SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
+ ssl->state++;
+ return( 0 );
+ }
+
+ if( ssl->session_negotiate->peer_cert == NULL )
+ {
+ SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
+ ssl->state++;
+ return( 0 );
+ }
+
+ ssl->handshake->calc_verify( ssl, hash );
+
+ if( ( ret = ssl_read_record( ssl ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_read_record", ret );
+ return( ret );
+ }
+
+ ssl->state++;
+
+ if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
+ }
+
+ if( ssl->in_msg[0] != SSL_HS_CERTIFICATE_VERIFY )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
+ }
+
+ /*
+ * 0 . 0 handshake type
+ * 1 . 3 handshake length
+ * 4 . 5 sig alg (TLS 1.2 only)
+ * 4+n . 5+n signature length (n = sa_len)
+ * 6+n . 6+n+m signature (m = sig_len)
+ */
+
+#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \
+ defined(POLARSSL_SSL_PROTO_TLS1_1)
+ if( ssl->minor_ver != SSL_MINOR_VERSION_3 )
+ {
+ sa_len = 0;
+
+ md_alg = POLARSSL_MD_NONE;
+ hashlen = 36;
+
+ /* For ECDSA, use SHA-1, not MD-5 + SHA-1 */
+ if( pk_can_do( &ssl->session_negotiate->peer_cert->pk,
+ POLARSSL_PK_ECDSA ) )
+ {
+ hash_start += 16;
+ hashlen -= 16;
+ md_alg = POLARSSL_MD_SHA1;
+ }
+ }
+ else
+#endif /* POLARSSL_SSL_PROTO_SSL3 || POLARSSL_SSL_PROTO_TLS1 ||
+ POLARSSL_SSL_PROTO_TLS1_1 */
+#if defined(POLARSSL_SSL_PROTO_TLS1_2)
+ if( ssl->minor_ver == SSL_MINOR_VERSION_3 )
+ {
+ sa_len = 2;
+
+ /*
+ * Hash
+ */
+ if( ssl->in_msg[4] != ssl->handshake->verify_sig_alg )
+ {
+ SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg"
+ " for verify message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
+ }
+
+ md_alg = ssl_md_alg_from_hash( ssl->handshake->verify_sig_alg );
+
+ /* Info from md_alg will be used instead */
+ hashlen = 0;
+
+ /*
+ * Signature
+ */
+ if( ( pk_alg = ssl_pk_alg_from_sig( ssl->in_msg[5] ) )
+ == POLARSSL_PK_NONE )
+ {
+ SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg"
+ " for verify message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
+ }
+
+ /*
+ * Check the certificate's key type matches the signature alg
+ */
+ if( ! pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) )
+ {
+ SSL_DEBUG_MSG( 1, ( "sig_alg doesn't match cert key" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
+ }
+ }
+ else
+#endif /* POLARSSL_SSL_PROTO_TLS1_2 */
+ {
+ SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( POLARSSL_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ sig_len = ( ssl->in_msg[4 + sa_len] << 8 ) | ssl->in_msg[5 + sa_len];
+
+ if( sa_len + sig_len + 6 != ssl->in_hslen )
+ {
+ SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
+ return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
+ }
+
+ if( ( ret = pk_verify( &ssl->session_negotiate->peer_cert->pk,
+ md_alg, hash_start, hashlen,
+ ssl->in_msg + 6 + sa_len, sig_len ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "pk_verify", ret );
+ return( ret );
+ }
+
+ SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) );
+
+ return( ret );
+}
+#endif /* !POLARSSL_KEY_EXCHANGE_RSA_ENABLED &&
+ !POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED &&
+ !POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED */
+
+#if defined(POLARSSL_SSL_SESSION_TICKETS)
+static int ssl_write_new_session_ticket( ssl_context *ssl )
+{
+ int ret;
+ size_t tlen;
+ uint32_t lifetime = (uint32_t) ssl->ticket_lifetime;
+
+ SSL_DEBUG_MSG( 2, ( "=> write new session ticket" ) );
+
+ ssl->out_msgtype = SSL_MSG_HANDSHAKE;
+ ssl->out_msg[0] = SSL_HS_NEW_SESSION_TICKET;
+
+ /*
+ * struct {
+ * uint32 ticket_lifetime_hint;
+ * opaque ticket<0..2^16-1>;
+ * } NewSessionTicket;
+ *
+ * 4 . 7 ticket_lifetime_hint (0 = unspecified)
+ * 8 . 9 ticket_len (n)
+ * 10 . 9+n ticket content
+ */
+
+ ssl->out_msg[4] = ( lifetime >> 24 ) & 0xFF;
+ ssl->out_msg[5] = ( lifetime >> 16 ) & 0xFF;
+ ssl->out_msg[6] = ( lifetime >> 8 ) & 0xFF;
+ ssl->out_msg[7] = ( lifetime ) & 0xFF;
+
+ if( ( ret = ssl_write_ticket( ssl, &tlen ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_write_ticket", ret );
+ tlen = 0;
+ }
+
+ ssl->out_msg[8] = (unsigned char)( ( tlen >> 8 ) & 0xFF );
+ ssl->out_msg[9] = (unsigned char)( ( tlen ) & 0xFF );
+
+ ssl->out_msglen = 10 + tlen;
+
+ /*
+ * Morally equivalent to updating ssl->state, but NewSessionTicket and
+ * ChangeCipherSpec share the same state.
+ */
+ ssl->handshake->new_session_ticket = 0;
+
+ if( ( ret = ssl_write_record( ssl ) ) != 0 )
+ {
+ SSL_DEBUG_RET( 1, "ssl_write_record", ret );
+ return( ret );
+ }
+
+ SSL_DEBUG_MSG( 2, ( "<= write new session ticket" ) );
+
+ return( 0 );
+}
+#endif /* POLARSSL_SSL_SESSION_TICKETS */
+
+/*
+ * SSL handshake -- server side -- single step
+ */
+int ssl_handshake_server_step( ssl_context *ssl )
+{
+ int ret = 0;
+
+ if( ssl->state == SSL_HANDSHAKE_OVER )
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+
+ SSL_DEBUG_MSG( 2, ( "server state: %d", ssl->state ) );
+
+ if( ( ret = ssl_flush_output( ssl ) ) != 0 )
+ return( ret );
+
+ switch( ssl->state )
+ {
+ case SSL_HELLO_REQUEST:
+ ssl->state = SSL_CLIENT_HELLO;
+ break;
+
+ /*
+ * <== ClientHello
+ */
+ case SSL_CLIENT_HELLO:
+ ret = ssl_parse_client_hello( ssl );
+ break;
+
+ /*
+ * ==> ServerHello
+ * Certificate
+ * ( ServerKeyExchange )
+ * ( CertificateRequest )
+ * ServerHelloDone
+ */
+ case SSL_SERVER_HELLO:
+ ret = ssl_write_server_hello( ssl );
+ break;
+
+ case SSL_SERVER_CERTIFICATE:
+ ret = ssl_write_certificate( ssl );
+ break;
+
+ case SSL_SERVER_KEY_EXCHANGE:
+ ret = ssl_write_server_key_exchange( ssl );
+ break;
+
+ case SSL_CERTIFICATE_REQUEST:
+ ret = ssl_write_certificate_request( ssl );
+ break;
+
+ case SSL_SERVER_HELLO_DONE:
+ ret = ssl_write_server_hello_done( ssl );
+ break;
+
+ /*
+ * <== ( Certificate/Alert )
+ * ClientKeyExchange
+ * ( CertificateVerify )
+ * ChangeCipherSpec
+ * Finished
+ */
+ case SSL_CLIENT_CERTIFICATE:
+ ret = ssl_parse_certificate( ssl );
+ break;
+
+ case SSL_CLIENT_KEY_EXCHANGE:
+ ret = ssl_parse_client_key_exchange( ssl );
+ break;
+
+ case SSL_CERTIFICATE_VERIFY:
+ ret = ssl_parse_certificate_verify( ssl );
+ break;
+
+ case SSL_CLIENT_CHANGE_CIPHER_SPEC:
+ ret = ssl_parse_change_cipher_spec( ssl );
+ break;
+
+ case SSL_CLIENT_FINISHED:
+ ret = ssl_parse_finished( ssl );
+ break;
+
+ /*
+ * ==> ( NewSessionTicket )
+ * ChangeCipherSpec
+ * Finished
+ */
+ case SSL_SERVER_CHANGE_CIPHER_SPEC:
+#if defined(POLARSSL_SSL_SESSION_TICKETS)
+ if( ssl->handshake->new_session_ticket != 0 )
+ ret = ssl_write_new_session_ticket( ssl );
+ else
+#endif
+ ret = ssl_write_change_cipher_spec( ssl );
+ break;
+
+ case SSL_SERVER_FINISHED:
+ ret = ssl_write_finished( ssl );
+ break;
+
+ case SSL_FLUSH_BUFFERS:
+ SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
+ ssl->state = SSL_HANDSHAKE_WRAPUP;
+ break;
+
+ case SSL_HANDSHAKE_WRAPUP:
+ ssl_handshake_wrapup( ssl );
+ break;
+
+ default:
+ SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
+ return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
+ }
+
+ return( ret );
+}
+#endif /* POLARSSL_SSL_SRV_C */
+