Doug Anson
mbed TLS library
Dependents: HTTPClient-SSL WS_SERVER
Diff: polarssl/x509_crt.c
- Revision:
- 0:137634ff4186
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/polarssl/x509_crt.c Thu Jun 11 03:27:03 2015 +0000
@@ -0,0 +1,2158 @@
+/*
+ * X.509 certificate parsing and verification
+ *
+ * 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.
+ */
+/*
+ * The ITU-T X.509 standard defines a certificate format for PKI.
+ *
+ * http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)
+ * http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)
+ * http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)
+ *
+ * http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf
+ * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
+ */
+
+#if !defined(POLARSSL_CONFIG_FILE)
+#include "polarssl/config.h"
+#else
+#include POLARSSL_CONFIG_FILE
+#endif
+
+#if defined(POLARSSL_X509_CRT_PARSE_C)
+
+#include "polarssl/x509_crt.h"
+#include "polarssl/oid.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#if defined(POLARSSL_PEM_PARSE_C)
+#include "polarssl/pem.h"
+#endif
+
+#if defined(POLARSSL_PLATFORM_C)
+#include "polarssl/platform.h"
+#else
+#include <stdlib.h>
+#define polarssl_free free
+#define polarssl_malloc malloc
+#define polarssl_snprintf snprintf
+#endif
+
+#if defined(POLARSSL_THREADING_C)
+#include "polarssl/threading.h"
+#endif
+
+#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+#include <windows.h>
+#else
+#include <time.h>
+#endif
+
+#if defined(POLARSSL_FS_IO)
+#include <stdio.h>
+#if !defined(_WIN32) || defined(EFIX64) || defined(EFI32)
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#endif /* !_WIN32 || EFIX64 || EFI32 */
+#endif
+
+/* 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;
+}
+
+/*
+ * Version ::= INTEGER { v1(0), v2(1), v3(2) }
+ */
+static int x509_get_version( unsigned char **p,
+ const unsigned char *end,
+ int *ver )
+{
+ int ret;
+ size_t len;
+
+ if( ( ret = asn1_get_tag( p, end, &len,
+ ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 0 ) ) != 0 )
+ {
+ if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ {
+ *ver = 0;
+ return( 0 );
+ }
+
+ return( ret );
+ }
+
+ end = *p + len;
+
+ if( ( ret = asn1_get_int( p, end, ver ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_VERSION + ret );
+
+ if( *p != end )
+ return( POLARSSL_ERR_X509_INVALID_VERSION +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ return( 0 );
+}
+
+/*
+ * Validity ::= SEQUENCE {
+ * notBefore Time,
+ * notAfter Time }
+ */
+static int x509_get_dates( unsigned char **p,
+ const unsigned char *end,
+ x509_time *from,
+ x509_time *to )
+{
+ int ret;
+ size_t len;
+
+ if( ( ret = asn1_get_tag( p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_DATE + ret );
+
+ end = *p + len;
+
+ if( ( ret = x509_get_time( p, end, from ) ) != 0 )
+ return( ret );
+
+ if( ( ret = x509_get_time( p, end, to ) ) != 0 )
+ return( ret );
+
+ if( *p != end )
+ return( POLARSSL_ERR_X509_INVALID_DATE +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ return( 0 );
+}
+
+/*
+ * X.509 v2/v3 unique identifier (not parsed)
+ */
+static int x509_get_uid( unsigned char **p,
+ const unsigned char *end,
+ x509_buf *uid, int n )
+{
+ int ret;
+
+ if( *p == end )
+ return( 0 );
+
+ uid->tag = **p;
+
+ if( ( ret = asn1_get_tag( p, end, &uid->len,
+ ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | n ) ) != 0 )
+ {
+ if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ return( 0 );
+
+ return( ret );
+ }
+
+ uid->p = *p;
+ *p += uid->len;
+
+ return( 0 );
+}
+
+static int x509_get_basic_constraints( unsigned char **p,
+ const unsigned char *end,
+ int *ca_istrue,
+ int *max_pathlen )
+{
+ int ret;
+ size_t len;
+
+ /*
+ * BasicConstraints ::= SEQUENCE {
+ * cA BOOLEAN DEFAULT FALSE,
+ * pathLenConstraint INTEGER (0..MAX) OPTIONAL }
+ */
+ *ca_istrue = 0; /* DEFAULT FALSE */
+ *max_pathlen = 0; /* endless */
+
+ if( ( ret = asn1_get_tag( p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ if( *p == end )
+ return( 0 );
+
+ if( ( ret = asn1_get_bool( p, end, ca_istrue ) ) != 0 )
+ {
+ if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ ret = asn1_get_int( p, end, ca_istrue );
+
+ if( ret != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ if( *ca_istrue != 0 )
+ *ca_istrue = 1;
+ }
+
+ if( *p == end )
+ return( 0 );
+
+ if( ( ret = asn1_get_int( p, end, max_pathlen ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ if( *p != end )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ (*max_pathlen)++;
+
+ return( 0 );
+}
+
+static int x509_get_ns_cert_type( unsigned char **p,
+ const unsigned char *end,
+ unsigned char *ns_cert_type)
+{
+ int ret;
+ x509_bitstring bs = { 0, 0, NULL };
+
+ if( ( ret = asn1_get_bitstring( p, end, &bs ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ if( bs.len != 1 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_INVALID_LENGTH );
+
+ /* Get actual bitstring */
+ *ns_cert_type = *bs.p;
+ return( 0 );
+}
+
+static int x509_get_key_usage( unsigned char **p,
+ const unsigned char *end,
+ unsigned char *key_usage)
+{
+ int ret;
+ x509_bitstring bs = { 0, 0, NULL };
+
+ if( ( ret = asn1_get_bitstring( p, end, &bs ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ if( bs.len < 1 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_INVALID_LENGTH );
+
+ /* Get actual bitstring */
+ *key_usage = *bs.p;
+ return( 0 );
+}
+
+/*
+ * ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
+ *
+ * KeyPurposeId ::= OBJECT IDENTIFIER
+ */
+static int x509_get_ext_key_usage( unsigned char **p,
+ const unsigned char *end,
+ x509_sequence *ext_key_usage)
+{
+ int ret;
+
+ if( ( ret = asn1_get_sequence_of( p, end, ext_key_usage, ASN1_OID ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ /* Sequence length must be >= 1 */
+ if( ext_key_usage->buf.p == NULL )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_INVALID_LENGTH );
+
+ return( 0 );
+}
+
+/*
+ * SubjectAltName ::= GeneralNames
+ *
+ * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
+ *
+ * GeneralName ::= CHOICE {
+ * otherName [0] OtherName,
+ * rfc822Name [1] IA5String,
+ * dNSName [2] IA5String,
+ * x400Address [3] ORAddress,
+ * directoryName [4] Name,
+ * ediPartyName [5] EDIPartyName,
+ * uniformResourceIdentifier [6] IA5String,
+ * iPAddress [7] OCTET STRING,
+ * registeredID [8] OBJECT IDENTIFIER }
+ *
+ * OtherName ::= SEQUENCE {
+ * type-id OBJECT IDENTIFIER,
+ * value [0] EXPLICIT ANY DEFINED BY type-id }
+ *
+ * EDIPartyName ::= SEQUENCE {
+ * nameAssigner [0] DirectoryString OPTIONAL,
+ * partyName [1] DirectoryString }
+ *
+ * NOTE: we only parse and use dNSName at this point.
+ */
+static int x509_get_subject_alt_name( unsigned char **p,
+ const unsigned char *end,
+ x509_sequence *subject_alt_name )
+{
+ int ret;
+ size_t len, tag_len;
+ asn1_buf *buf;
+ unsigned char tag;
+ asn1_sequence *cur = subject_alt_name;
+
+ /* Get main sequence tag */
+ if( ( ret = asn1_get_tag( p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ if( *p + len != end )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ while( *p < end )
+ {
+ if( ( end - *p ) < 1 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ tag = **p;
+ (*p)++;
+ if( ( ret = asn1_get_len( p, end, &tag_len ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ if( ( tag & ASN1_CONTEXT_SPECIFIC ) != ASN1_CONTEXT_SPECIFIC )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
+
+ /* Skip everything but DNS name */
+ if( tag != ( ASN1_CONTEXT_SPECIFIC | 2 ) )
+ {
+ *p += tag_len;
+ continue;
+ }
+
+ /* Allocate and assign next pointer */
+ if( cur->buf.p != NULL )
+ {
+ if( cur->next != NULL )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS );
+
+ cur->next = polarssl_malloc( sizeof( asn1_sequence ) );
+
+ if( cur->next == NULL )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_MALLOC_FAILED );
+
+ memset( cur->next, 0, sizeof( asn1_sequence ) );
+ cur = cur->next;
+ }
+
+ buf = &(cur->buf);
+ buf->tag = tag;
+ buf->p = *p;
+ buf->len = tag_len;
+ *p += buf->len;
+ }
+
+ /* Set final sequence entry's next pointer to NULL */
+ cur->next = NULL;
+
+ if( *p != end )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ return( 0 );
+}
+
+/*
+ * X.509 v3 extensions
+ *
+ * TODO: Perform all of the basic constraints tests required by the RFC
+ * TODO: Set values for undetected extensions to a sane default?
+ *
+ */
+static int x509_get_crt_ext( unsigned char **p,
+ const unsigned char *end,
+ x509_crt *crt )
+{
+ int ret;
+ size_t len;
+ unsigned char *end_ext_data, *end_ext_octet;
+
+ if( ( ret = x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
+ {
+ if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ return( 0 );
+
+ return( ret );
+ }
+
+ while( *p < end )
+ {
+ /*
+ * Extension ::= SEQUENCE {
+ * extnID OBJECT IDENTIFIER,
+ * critical BOOLEAN DEFAULT FALSE,
+ * extnValue OCTET STRING }
+ */
+ x509_buf extn_oid = {0, 0, NULL};
+ int is_critical = 0; /* DEFAULT FALSE */
+ int ext_type = 0;
+
+ if( ( ret = asn1_get_tag( p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ end_ext_data = *p + len;
+
+ /* Get extension ID */
+ extn_oid.tag = **p;
+
+ if( ( ret = asn1_get_tag( p, end, &extn_oid.len, ASN1_OID ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ extn_oid.p = *p;
+ *p += extn_oid.len;
+
+ if( ( end - *p ) < 1 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ /* Get optional critical */
+ if( ( ret = asn1_get_bool( p, end_ext_data, &is_critical ) ) != 0 &&
+ ( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ /* Data should be octet string type */
+ if( ( ret = asn1_get_tag( p, end_ext_data, &len,
+ ASN1_OCTET_STRING ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret );
+
+ end_ext_octet = *p + len;
+
+ if( end_ext_octet != end_ext_data )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ /*
+ * Detect supported extensions
+ */
+ ret = oid_get_x509_ext_type( &extn_oid, &ext_type );
+
+ if( ret != 0 )
+ {
+ /* No parser found, skip extension */
+ *p = end_ext_octet;
+
+#if !defined(POLARSSL_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION)
+ if( is_critical )
+ {
+ /* Data is marked as critical: fail */
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
+ }
+#endif
+ continue;
+ }
+
+ /* Forbid repeated extensions */
+ if( ( crt->ext_types & ext_type ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS );
+
+ crt->ext_types |= ext_type;
+
+ switch( ext_type )
+ {
+ case EXT_BASIC_CONSTRAINTS:
+ /* Parse basic constraints */
+ if( ( ret = x509_get_basic_constraints( p, end_ext_octet,
+ &crt->ca_istrue, &crt->max_pathlen ) ) != 0 )
+ return( ret );
+ break;
+
+ case EXT_KEY_USAGE:
+ /* Parse key usage */
+ if( ( ret = x509_get_key_usage( p, end_ext_octet,
+ &crt->key_usage ) ) != 0 )
+ return( ret );
+ break;
+
+ case EXT_EXTENDED_KEY_USAGE:
+ /* Parse extended key usage */
+ if( ( ret = x509_get_ext_key_usage( p, end_ext_octet,
+ &crt->ext_key_usage ) ) != 0 )
+ return( ret );
+ break;
+
+ case EXT_SUBJECT_ALT_NAME:
+ /* Parse subject alt name */
+ if( ( ret = x509_get_subject_alt_name( p, end_ext_octet,
+ &crt->subject_alt_names ) ) != 0 )
+ return( ret );
+ break;
+
+ case EXT_NS_CERT_TYPE:
+ /* Parse netscape certificate type */
+ if( ( ret = x509_get_ns_cert_type( p, end_ext_octet,
+ &crt->ns_cert_type ) ) != 0 )
+ return( ret );
+ break;
+
+ default:
+ return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE );
+ }
+ }
+
+ if( *p != end )
+ return( POLARSSL_ERR_X509_INVALID_EXTENSIONS +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ return( 0 );
+}
+
+/*
+ * Parse and fill a single X.509 certificate in DER format
+ */
+static int x509_crt_parse_der_core( x509_crt *crt, const unsigned char *buf,
+ size_t buflen )
+{
+ int ret;
+ size_t len;
+ unsigned char *p, *end, *crt_end;
+ x509_buf sig_params1, sig_params2;
+
+ memset( &sig_params1, 0, sizeof( x509_buf ) );
+ memset( &sig_params2, 0, sizeof( x509_buf ) );
+
+ /*
+ * Check for valid input
+ */
+ if( crt == NULL || buf == NULL )
+ return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
+
+ p = polarssl_malloc( len = buflen );
+
+ if( p == NULL )
+ return( POLARSSL_ERR_X509_MALLOC_FAILED );
+
+ memcpy( p, buf, buflen );
+
+ crt->raw.p = p;
+ crt->raw.len = len;
+ end = p + len;
+
+ /*
+ * Certificate ::= SEQUENCE {
+ * tbsCertificate TBSCertificate,
+ * signatureAlgorithm AlgorithmIdentifier,
+ * signatureValue BIT STRING }
+ */
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_INVALID_FORMAT );
+ }
+
+ if( len > (size_t) ( end - p ) )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_INVALID_FORMAT +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+ }
+ crt_end = p + len;
+
+ /*
+ * TBSCertificate ::= SEQUENCE {
+ */
+ crt->tbs.p = p;
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_INVALID_FORMAT + ret );
+ }
+
+ end = p + len;
+ crt->tbs.len = end - crt->tbs.p;
+
+ /*
+ * Version ::= INTEGER { v1(0), v2(1), v3(2) }
+ *
+ * CertificateSerialNumber ::= INTEGER
+ *
+ * signature AlgorithmIdentifier
+ */
+ if( ( ret = x509_get_version( &p, end, &crt->version ) ) != 0 ||
+ ( ret = x509_get_serial( &p, end, &crt->serial ) ) != 0 ||
+ ( ret = x509_get_alg( &p, end, &crt->sig_oid1,
+ &sig_params1 ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+
+ crt->version++;
+
+ if( crt->version > 3 )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_UNKNOWN_VERSION );
+ }
+
+ if( ( ret = x509_get_sig_alg( &crt->sig_oid1, &sig_params1,
+ &crt->sig_md, &crt->sig_pk,
+ &crt->sig_opts ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+
+ /*
+ * issuer Name
+ */
+ crt->issuer_raw.p = p;
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_INVALID_FORMAT + ret );
+ }
+
+ if( ( ret = x509_get_name( &p, p + len, &crt->issuer ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+
+ crt->issuer_raw.len = p - crt->issuer_raw.p;
+
+ /*
+ * Validity ::= SEQUENCE {
+ * notBefore Time,
+ * notAfter Time }
+ *
+ */
+ if( ( ret = x509_get_dates( &p, end, &crt->valid_from,
+ &crt->valid_to ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+
+ /*
+ * subject Name
+ */
+ crt->subject_raw.p = p;
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_INVALID_FORMAT + ret );
+ }
+
+ if( len && ( ret = x509_get_name( &p, p + len, &crt->subject ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+
+ crt->subject_raw.len = p - crt->subject_raw.p;
+
+ /*
+ * SubjectPublicKeyInfo
+ */
+ if( ( ret = pk_parse_subpubkey( &p, end, &crt->pk ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+
+ /*
+ * issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
+ * -- If present, version shall be v2 or v3
+ * subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
+ * -- If present, version shall be v2 or v3
+ * extensions [3] EXPLICIT Extensions OPTIONAL
+ * -- If present, version shall be v3
+ */
+ if( crt->version == 2 || crt->version == 3 )
+ {
+ ret = x509_get_uid( &p, end, &crt->issuer_id, 1 );
+ if( ret != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+ }
+
+ if( crt->version == 2 || crt->version == 3 )
+ {
+ ret = x509_get_uid( &p, end, &crt->subject_id, 2 );
+ if( ret != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+ }
+
+#if !defined(POLARSSL_X509_ALLOW_EXTENSIONS_NON_V3)
+ if( crt->version == 3 )
+ {
+#endif
+ ret = x509_get_crt_ext( &p, end, crt );
+ if( ret != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+#if !defined(POLARSSL_X509_ALLOW_EXTENSIONS_NON_V3)
+ }
+#endif
+
+ if( p != end )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_INVALID_FORMAT +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+ }
+
+ end = crt_end;
+
+ /*
+ * }
+ * -- end of TBSCertificate
+ *
+ * signatureAlgorithm AlgorithmIdentifier,
+ * signatureValue BIT STRING
+ */
+ if( ( ret = x509_get_alg( &p, end, &crt->sig_oid2, &sig_params2 ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+
+ if( crt->sig_oid1.len != crt->sig_oid2.len ||
+ memcmp( crt->sig_oid1.p, crt->sig_oid2.p, crt->sig_oid1.len ) != 0 ||
+ sig_params1.len != sig_params2.len ||
+ ( sig_params1.len != 0 &&
+ memcmp( sig_params1.p, sig_params2.p, sig_params1.len ) != 0 ) )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_SIG_MISMATCH );
+ }
+
+ if( ( ret = x509_get_sig( &p, end, &crt->sig ) ) != 0 )
+ {
+ x509_crt_free( crt );
+ return( ret );
+ }
+
+ if( p != end )
+ {
+ x509_crt_free( crt );
+ return( POLARSSL_ERR_X509_INVALID_FORMAT +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+ }
+
+ return( 0 );
+}
+
+/*
+ * Parse one X.509 certificate in DER format from a buffer and add them to a
+ * chained list
+ */
+int x509_crt_parse_der( x509_crt *chain, const unsigned char *buf,
+ size_t buflen )
+{
+ int ret;
+ x509_crt *crt = chain, *prev = NULL;
+
+ /*
+ * Check for valid input
+ */
+ if( crt == NULL || buf == NULL )
+ return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
+
+ while( crt->version != 0 && crt->next != NULL )
+ {
+ prev = crt;
+ crt = crt->next;
+ }
+
+ /*
+ * Add new certificate on the end of the chain if needed.
+ */
+ if( crt->version != 0 && crt->next == NULL )
+ {
+ crt->next = polarssl_malloc( sizeof( x509_crt ) );
+
+ if( crt->next == NULL )
+ return( POLARSSL_ERR_X509_MALLOC_FAILED );
+
+ prev = crt;
+ x509_crt_init( crt->next );
+ crt = crt->next;
+ }
+
+ if( ( ret = x509_crt_parse_der_core( crt, buf, buflen ) ) != 0 )
+ {
+ if( prev )
+ prev->next = NULL;
+
+ if( crt != chain )
+ polarssl_free( crt );
+
+ return( ret );
+ }
+
+ return( 0 );
+}
+
+/*
+ * Parse one or more PEM certificates from a buffer and add them to the chained
+ * list
+ */
+int x509_crt_parse( x509_crt *chain, const unsigned char *buf, size_t buflen )
+{
+ int success = 0, first_error = 0, total_failed = 0;
+ int buf_format = X509_FORMAT_DER;
+
+ /*
+ * Check for valid input
+ */
+ if( chain == NULL || buf == NULL )
+ return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
+
+ /*
+ * Determine buffer content. Buffer contains either one DER certificate or
+ * one or more PEM certificates.
+ */
+#if defined(POLARSSL_PEM_PARSE_C)
+ if( strstr( (const char *) buf, "-----BEGIN CERTIFICATE-----" ) != NULL )
+ buf_format = X509_FORMAT_PEM;
+#endif
+
+ if( buf_format == X509_FORMAT_DER )
+ return x509_crt_parse_der( chain, buf, buflen );
+
+#if defined(POLARSSL_PEM_PARSE_C)
+ if( buf_format == X509_FORMAT_PEM )
+ {
+ int ret;
+ pem_context pem;
+
+ while( buflen > 0 )
+ {
+ size_t use_len;
+ pem_init( &pem );
+
+ ret = pem_read_buffer( &pem,
+ "-----BEGIN CERTIFICATE-----",
+ "-----END CERTIFICATE-----",
+ buf, NULL, 0, &use_len );
+
+ if( ret == 0 )
+ {
+ /*
+ * Was PEM encoded
+ */
+ buflen -= use_len;
+ buf += use_len;
+ }
+ else if( ret == POLARSSL_ERR_PEM_BAD_INPUT_DATA )
+ {
+ return( ret );
+ }
+ else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+ {
+ pem_free( &pem );
+
+ /*
+ * PEM header and footer were found
+ */
+ buflen -= use_len;
+ buf += use_len;
+
+ if( first_error == 0 )
+ first_error = ret;
+
+ total_failed++;
+ continue;
+ }
+ else
+ break;
+
+ ret = x509_crt_parse_der( chain, pem.buf, pem.buflen );
+
+ pem_free( &pem );
+
+ if( ret != 0 )
+ {
+ /*
+ * Quit parsing on a memory error
+ */
+ if( ret == POLARSSL_ERR_X509_MALLOC_FAILED )
+ return( ret );
+
+ if( first_error == 0 )
+ first_error = ret;
+
+ total_failed++;
+ continue;
+ }
+
+ success = 1;
+ }
+ }
+#endif /* POLARSSL_PEM_PARSE_C */
+
+ if( success )
+ return( total_failed );
+ else if( first_error )
+ return( first_error );
+ else
+ return( POLARSSL_ERR_X509_CERT_UNKNOWN_FORMAT );
+}
+
+#if defined(POLARSSL_FS_IO)
+/*
+ * Load one or more certificates and add them to the chained list
+ */
+int x509_crt_parse_file( x509_crt *chain, const char *path )
+{
+ int ret;
+ size_t n;
+ unsigned char *buf;
+
+ if( ( ret = pk_load_file( path, &buf, &n ) ) != 0 )
+ return( ret );
+
+ ret = x509_crt_parse( chain, buf, n );
+
+ polarssl_zeroize( buf, n + 1 );
+ polarssl_free( buf );
+
+ return( ret );
+}
+
+#if defined(POLARSSL_THREADING_PTHREAD)
+static threading_mutex_t readdir_mutex = PTHREAD_MUTEX_INITIALIZER;
+#endif
+
+int x509_crt_parse_path( x509_crt *chain, const char *path )
+{
+ int ret = 0;
+#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+ int w_ret;
+ WCHAR szDir[MAX_PATH];
+ char filename[MAX_PATH];
+ char *p;
+ int len = (int) strlen( path );
+
+ WIN32_FIND_DATAW file_data;
+ HANDLE hFind;
+
+ if( len > MAX_PATH - 3 )
+ return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
+
+ memset( szDir, 0, sizeof(szDir) );
+ memset( filename, 0, MAX_PATH );
+ memcpy( filename, path, len );
+ filename[len++] = '\\';
+ p = filename + len;
+ filename[len++] = '*';
+
+ w_ret = MultiByteToWideChar( CP_ACP, 0, filename, len, szDir,
+ MAX_PATH - 3 );
+ if( w_ret == 0 )
+ return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
+
+ hFind = FindFirstFileW( szDir, &file_data );
+ if( hFind == INVALID_HANDLE_VALUE )
+ return( POLARSSL_ERR_X509_FILE_IO_ERROR );
+
+ len = MAX_PATH - len;
+ do
+ {
+ memset( p, 0, len );
+
+ if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
+ continue;
+
+ w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName,
+ lstrlenW( file_data.cFileName ),
+ p, len - 1,
+ NULL, NULL );
+ if( w_ret == 0 )
+ return( POLARSSL_ERR_X509_FILE_IO_ERROR );
+
+ w_ret = x509_crt_parse_file( chain, filename );
+ if( w_ret < 0 )
+ ret++;
+ else
+ ret += w_ret;
+ }
+ while( FindNextFileW( hFind, &file_data ) != 0 );
+
+ if( GetLastError() != ERROR_NO_MORE_FILES )
+ ret = POLARSSL_ERR_X509_FILE_IO_ERROR;
+
+ FindClose( hFind );
+#else /* _WIN32 */
+ int t_ret;
+ struct stat sb;
+ struct dirent *entry;
+ char entry_name[255];
+ DIR *dir = opendir( path );
+
+ if( dir == NULL )
+ return( POLARSSL_ERR_X509_FILE_IO_ERROR );
+
+#if defined(POLARSSL_THREADING_PTHREAD)
+ if( ( ret = polarssl_mutex_lock( &readdir_mutex ) ) != 0 )
+ return( ret );
+#endif
+
+ while( ( entry = readdir( dir ) ) != NULL )
+ {
+ polarssl_snprintf( entry_name, sizeof entry_name, "%s/%s", path, entry->d_name );
+
+ if( stat( entry_name, &sb ) == -1 )
+ {
+ closedir( dir );
+ ret = POLARSSL_ERR_X509_FILE_IO_ERROR;
+ goto cleanup;
+ }
+
+ if( !S_ISREG( sb.st_mode ) )
+ continue;
+
+ // Ignore parse errors
+ //
+ t_ret = x509_crt_parse_file( chain, entry_name );
+ if( t_ret < 0 )
+ ret++;
+ else
+ ret += t_ret;
+ }
+ closedir( dir );
+
+cleanup:
+#if defined(POLARSSL_THREADING_PTHREAD)
+ if( polarssl_mutex_unlock( &readdir_mutex ) != 0 )
+ ret = POLARSSL_ERR_THREADING_MUTEX_ERROR;
+#endif
+
+#endif /* _WIN32 */
+
+ return( ret );
+}
+#endif /* POLARSSL_FS_IO */
+
+#if defined(_MSC_VER) && !defined snprintf && !defined(EFIX64) && \
+ !defined(EFI32)
+#include <stdarg.h>
+
+#if !defined vsnprintf
+#define vsnprintf _vsnprintf
+#endif // vsnprintf
+
+/*
+ * Windows _snprintf and _vsnprintf are not compatible to linux versions.
+ * Result value is not size of buffer needed, but -1 if no fit is possible.
+ *
+ * This fuction tries to 'fix' this by at least suggesting enlarging the
+ * size by 20.
+ */
+static int compat_snprintf( char *str, size_t size, const char *format, ... )
+{
+ va_list ap;
+ int res = -1;
+
+ va_start( ap, format );
+
+ res = vsnprintf( str, size, format, ap );
+
+ va_end( ap );
+
+ // No quick fix possible
+ if( res < 0 )
+ return( (int) size + 20 );
+
+ return( res );
+}
+
+#define snprintf compat_snprintf
+#endif /* _MSC_VER && !snprintf && !EFIX64 && !EFI32 */
+
+#define POLARSSL_ERR_DEBUG_BUF_TOO_SMALL -2
+
+#define SAFE_SNPRINTF() \
+{ \
+ if( ret == -1 ) \
+ return( -1 ); \
+ \
+ if( (unsigned int) ret > n ) { \
+ p[n - 1] = '\0'; \
+ return( POLARSSL_ERR_DEBUG_BUF_TOO_SMALL ); \
+ } \
+ \
+ n -= (unsigned int) ret; \
+ p += (unsigned int) ret; \
+}
+
+static int x509_info_subject_alt_name( char **buf, size_t *size,
+ const x509_sequence *subject_alt_name )
+{
+ size_t i;
+ size_t n = *size;
+ char *p = *buf;
+ const x509_sequence *cur = subject_alt_name;
+ const char *sep = "";
+ size_t sep_len = 0;
+
+ while( cur != NULL )
+ {
+ if( cur->buf.len + sep_len >= n )
+ {
+ *p = '\0';
+ return( POLARSSL_ERR_DEBUG_BUF_TOO_SMALL );
+ }
+
+ n -= cur->buf.len + sep_len;
+ for( i = 0; i < sep_len; i++ )
+ *p++ = sep[i];
+ for( i = 0; i < cur->buf.len; i++ )
+ *p++ = cur->buf.p[i];
+
+ sep = ", ";
+ sep_len = 2;
+
+ cur = cur->next;
+ }
+
+ *p = '\0';
+
+ *size = n;
+ *buf = p;
+
+ return( 0 );
+}
+
+#define PRINT_ITEM(i) \
+ { \
+ ret = polarssl_snprintf( p, n, "%s" i, sep ); \
+ SAFE_SNPRINTF(); \
+ sep = ", "; \
+ }
+
+#define CERT_TYPE(type,name) \
+ if( ns_cert_type & type ) \
+ PRINT_ITEM( name );
+
+static int x509_info_cert_type( char **buf, size_t *size,
+ unsigned char ns_cert_type )
+{
+ int ret;
+ size_t n = *size;
+ char *p = *buf;
+ const char *sep = "";
+
+ CERT_TYPE( NS_CERT_TYPE_SSL_CLIENT, "SSL Client" );
+ CERT_TYPE( NS_CERT_TYPE_SSL_SERVER, "SSL Server" );
+ CERT_TYPE( NS_CERT_TYPE_EMAIL, "Email" );
+ CERT_TYPE( NS_CERT_TYPE_OBJECT_SIGNING, "Object Signing" );
+ CERT_TYPE( NS_CERT_TYPE_RESERVED, "Reserved" );
+ CERT_TYPE( NS_CERT_TYPE_SSL_CA, "SSL CA" );
+ CERT_TYPE( NS_CERT_TYPE_EMAIL_CA, "Email CA" );
+ CERT_TYPE( NS_CERT_TYPE_OBJECT_SIGNING_CA, "Object Signing CA" );
+
+ *size = n;
+ *buf = p;
+
+ return( 0 );
+}
+
+#define KEY_USAGE(code,name) \
+ if( key_usage & code ) \
+ PRINT_ITEM( name );
+
+static int x509_info_key_usage( char **buf, size_t *size,
+ unsigned char key_usage )
+{
+ int ret;
+ size_t n = *size;
+ char *p = *buf;
+ const char *sep = "";
+
+ KEY_USAGE( KU_DIGITAL_SIGNATURE, "Digital Signature" );
+ KEY_USAGE( KU_NON_REPUDIATION, "Non Repudiation" );
+ KEY_USAGE( KU_KEY_ENCIPHERMENT, "Key Encipherment" );
+ KEY_USAGE( KU_DATA_ENCIPHERMENT, "Data Encipherment" );
+ KEY_USAGE( KU_KEY_AGREEMENT, "Key Agreement" );
+ KEY_USAGE( KU_KEY_CERT_SIGN, "Key Cert Sign" );
+ KEY_USAGE( KU_CRL_SIGN, "CRL Sign" );
+
+ *size = n;
+ *buf = p;
+
+ return( 0 );
+}
+
+static int x509_info_ext_key_usage( char **buf, size_t *size,
+ const x509_sequence *extended_key_usage )
+{
+ int ret;
+ const char *desc;
+ size_t n = *size;
+ char *p = *buf;
+ const x509_sequence *cur = extended_key_usage;
+ const char *sep = "";
+
+ while( cur != NULL )
+ {
+ if( oid_get_extended_key_usage( &cur->buf, &desc ) != 0 )
+ desc = "???";
+
+ ret = polarssl_snprintf( p, n, "%s%s", sep, desc );
+ SAFE_SNPRINTF();
+
+ sep = ", ";
+
+ cur = cur->next;
+ }
+
+ *size = n;
+ *buf = p;
+
+ return( 0 );
+}
+
+/*
+ * Return an informational string about the certificate.
+ */
+#define BEFORE_COLON 18
+#define BC "18"
+int x509_crt_info( char *buf, size_t size, const char *prefix,
+ const x509_crt *crt )
+{
+ int ret;
+ size_t n;
+ char *p;
+ char key_size_str[BEFORE_COLON];
+
+ p = buf;
+ n = size;
+
+ ret = polarssl_snprintf( p, n, "%scert. version : %d\n",
+ prefix, crt->version );
+ SAFE_SNPRINTF();
+ ret = polarssl_snprintf( p, n, "%sserial number : ",
+ prefix );
+ SAFE_SNPRINTF();
+
+ ret = x509_serial_gets( p, n, &crt->serial );
+ SAFE_SNPRINTF();
+
+ ret = polarssl_snprintf( p, n, "\n%sissuer name : ", prefix );
+ SAFE_SNPRINTF();
+ ret = x509_dn_gets( p, n, &crt->issuer );
+ SAFE_SNPRINTF();
+
+ ret = polarssl_snprintf( p, n, "\n%ssubject name : ", prefix );
+ SAFE_SNPRINTF();
+ ret = x509_dn_gets( p, n, &crt->subject );
+ SAFE_SNPRINTF();
+
+ ret = polarssl_snprintf( p, n, "\n%sissued on : " \
+ "%04d-%02d-%02d %02d:%02d:%02d", prefix,
+ crt->valid_from.year, crt->valid_from.mon,
+ crt->valid_from.day, crt->valid_from.hour,
+ crt->valid_from.min, crt->valid_from.sec );
+ SAFE_SNPRINTF();
+
+ ret = polarssl_snprintf( p, n, "\n%sexpires on : " \
+ "%04d-%02d-%02d %02d:%02d:%02d", prefix,
+ crt->valid_to.year, crt->valid_to.mon,
+ crt->valid_to.day, crt->valid_to.hour,
+ crt->valid_to.min, crt->valid_to.sec );
+ SAFE_SNPRINTF();
+
+ ret = polarssl_snprintf( p, n, "\n%ssigned using : ", prefix );
+ SAFE_SNPRINTF();
+
+ ret = x509_sig_alg_gets( p, n, &crt->sig_oid1, crt->sig_pk,
+ crt->sig_md, crt->sig_opts );
+ SAFE_SNPRINTF();
+
+ /* Key size */
+ if( ( ret = x509_key_size_helper( key_size_str, BEFORE_COLON,
+ pk_get_name( &crt->pk ) ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ ret = polarssl_snprintf( p, n, "\n%s%-" BC "s: %d bits", prefix, key_size_str,
+ (int) pk_get_size( &crt->pk ) );
+ SAFE_SNPRINTF();
+
+ /*
+ * Optional extensions
+ */
+
+ if( crt->ext_types & EXT_BASIC_CONSTRAINTS )
+ {
+ ret = polarssl_snprintf( p, n, "\n%sbasic constraints : CA=%s", prefix,
+ crt->ca_istrue ? "true" : "false" );
+ SAFE_SNPRINTF();
+
+ if( crt->max_pathlen > 0 )
+ {
+ ret = polarssl_snprintf( p, n, ", max_pathlen=%d", crt->max_pathlen - 1 );
+ SAFE_SNPRINTF();
+ }
+ }
+
+ if( crt->ext_types & EXT_SUBJECT_ALT_NAME )
+ {
+ ret = polarssl_snprintf( p, n, "\n%ssubject alt name : ", prefix );
+ SAFE_SNPRINTF();
+
+ if( ( ret = x509_info_subject_alt_name( &p, &n,
+ &crt->subject_alt_names ) ) != 0 )
+ return( ret );
+ }
+
+ if( crt->ext_types & EXT_NS_CERT_TYPE )
+ {
+ ret = polarssl_snprintf( p, n, "\n%scert. type : ", prefix );
+ SAFE_SNPRINTF();
+
+ if( ( ret = x509_info_cert_type( &p, &n, crt->ns_cert_type ) ) != 0 )
+ return( ret );
+ }
+
+ if( crt->ext_types & EXT_KEY_USAGE )
+ {
+ ret = polarssl_snprintf( p, n, "\n%skey usage : ", prefix );
+ SAFE_SNPRINTF();
+
+ if( ( ret = x509_info_key_usage( &p, &n, crt->key_usage ) ) != 0 )
+ return( ret );
+ }
+
+ if( crt->ext_types & EXT_EXTENDED_KEY_USAGE )
+ {
+ ret = polarssl_snprintf( p, n, "\n%sext key usage : ", prefix );
+ SAFE_SNPRINTF();
+
+ if( ( ret = x509_info_ext_key_usage( &p, &n,
+ &crt->ext_key_usage ) ) != 0 )
+ return( ret );
+ }
+
+ ret = polarssl_snprintf( p, n, "\n" );
+ SAFE_SNPRINTF();
+
+ return( (int) ( size - n ) );
+}
+
+struct x509_crt_verify_string {
+ int code;
+ const char *string;
+};
+
+static const struct x509_crt_verify_string x509_crt_verify_strings[] = {
+ { BADCERT_EXPIRED, "The certificate validity has expired" },
+ { BADCERT_REVOKED, "The certificate has been revoked (is on a CRL)" },
+ { BADCERT_CN_MISMATCH, "The certificate Common Name (CN) does not match with the expected CN" },
+ { BADCERT_NOT_TRUSTED, "The certificate is not correctly signed by the trusted CA" },
+ { BADCRL_NOT_TRUSTED, "The CRL is not correctly signed by the trusted CA" },
+ { BADCRL_EXPIRED, "The CRL is expired" },
+ { BADCERT_MISSING, "Certificate was missing" },
+ { BADCERT_SKIP_VERIFY, "Certificate verification was skipped" },
+ { BADCERT_OTHER, "Other reason (can be used by verify callback)" },
+ { BADCERT_FUTURE, "The certificate validity starts in the future" },
+ { BADCRL_FUTURE, "The CRL is from the future" },
+ { BADCERT_KEY_USAGE, "Usage does not match the keyUsage extension" },
+ { BADCERT_EXT_KEY_USAGE, "Usage does not match the extendedKeyUsage extension" },
+ { BADCERT_NS_CERT_TYPE, "Usage does not match the nsCertType extension" },
+ { 0, NULL }
+};
+
+int x509_crt_verify_info( char *buf, size_t size, const char *prefix,
+ int flags )
+{
+ int ret;
+ const struct x509_crt_verify_string *cur;
+ char *p = buf;
+ size_t n = size;
+
+ for( cur = x509_crt_verify_strings; cur->string != NULL ; cur++ )
+ {
+ if( ( flags & cur->code ) == 0 )
+ continue;
+
+ ret = polarssl_snprintf( p, n, "%s%s\n", prefix, cur->string );
+ SAFE_SNPRINTF();
+ flags ^= cur->code;
+ }
+
+ if( flags != 0 )
+ {
+ ret = polarssl_snprintf( p, n, "%sUnknown reason "
+ "(this should not happen)\n", prefix );
+ SAFE_SNPRINTF();
+ }
+
+ return( (int) ( size - n ) );
+}
+
+#if defined(POLARSSL_X509_CHECK_KEY_USAGE)
+int x509_crt_check_key_usage( const x509_crt *crt, int usage )
+{
+ if( ( crt->ext_types & EXT_KEY_USAGE ) != 0 &&
+ ( crt->key_usage & usage ) != usage )
+ return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
+
+ return( 0 );
+}
+#endif
+
+#if defined(POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE)
+int x509_crt_check_extended_key_usage( const x509_crt *crt,
+ const char *usage_oid,
+ size_t usage_len )
+{
+ const x509_sequence *cur;
+
+ /* Extension is not mandatory, absent means no restriction */
+ if( ( crt->ext_types & EXT_EXTENDED_KEY_USAGE ) == 0 )
+ return( 0 );
+
+ /*
+ * Look for the requested usage (or wildcard ANY) in our list
+ */
+ for( cur = &crt->ext_key_usage; cur != NULL; cur = cur->next )
+ {
+ const x509_buf *cur_oid = &cur->buf;
+
+ if( cur_oid->len == usage_len &&
+ memcmp( cur_oid->p, usage_oid, usage_len ) == 0 )
+ {
+ return( 0 );
+ }
+
+ if( OID_CMP( OID_ANY_EXTENDED_KEY_USAGE, cur_oid ) )
+ return( 0 );
+ }
+
+ return( POLARSSL_ERR_X509_BAD_INPUT_DATA );
+}
+#endif /* POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE */
+
+#if defined(POLARSSL_X509_CRL_PARSE_C)
+/*
+ * Return 1 if the certificate is revoked, or 0 otherwise.
+ */
+int x509_crt_revoked( const x509_crt *crt, const x509_crl *crl )
+{
+ const x509_crl_entry *cur = &crl->entry;
+
+ while( cur != NULL && cur->serial.len != 0 )
+ {
+ if( crt->serial.len == cur->serial.len &&
+ memcmp( crt->serial.p, cur->serial.p, crt->serial.len ) == 0 )
+ {
+ if( x509_time_expired( &cur->revocation_date ) )
+ return( 1 );
+ }
+
+ cur = cur->next;
+ }
+
+ return( 0 );
+}
+
+/*
+ * Check that the given certificate is valid according to the CRL.
+ */
+static int x509_crt_verifycrl( x509_crt *crt, x509_crt *ca,
+ x509_crl *crl_list)
+{
+ int flags = 0;
+ unsigned char hash[POLARSSL_MD_MAX_SIZE];
+ const md_info_t *md_info;
+
+ if( ca == NULL )
+ return( flags );
+
+ /*
+ * TODO: What happens if no CRL is present?
+ * Suggestion: Revocation state should be unknown if no CRL is present.
+ * For backwards compatibility this is not yet implemented.
+ */
+
+ while( crl_list != NULL )
+ {
+ if( crl_list->version == 0 ||
+ crl_list->issuer_raw.len != ca->subject_raw.len ||
+ memcmp( crl_list->issuer_raw.p, ca->subject_raw.p,
+ crl_list->issuer_raw.len ) != 0 )
+ {
+ crl_list = crl_list->next;
+ continue;
+ }
+
+ /*
+ * Check if the CA is configured to sign CRLs
+ */
+#if defined(POLARSSL_X509_CHECK_KEY_USAGE)
+ if( x509_crt_check_key_usage( ca, KU_CRL_SIGN ) != 0 )
+ {
+ flags |= BADCRL_NOT_TRUSTED;
+ break;
+ }
+#endif
+
+ /*
+ * Check if CRL is correctly signed by the trusted CA
+ */
+ md_info = md_info_from_type( crl_list->sig_md );
+ if( md_info == NULL )
+ {
+ /*
+ * Cannot check 'unknown' hash
+ */
+ flags |= BADCRL_NOT_TRUSTED;
+ break;
+ }
+
+ md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash );
+
+ if( pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
+ crl_list->sig_md, hash, md_info->size,
+ crl_list->sig.p, crl_list->sig.len ) != 0 )
+ {
+ flags |= BADCRL_NOT_TRUSTED;
+ break;
+ }
+
+ /*
+ * Check for validity of CRL (Do not drop out)
+ */
+ if( x509_time_expired( &crl_list->next_update ) )
+ flags |= BADCRL_EXPIRED;
+
+ if( x509_time_future( &crl_list->this_update ) )
+ flags |= BADCRL_FUTURE;
+
+ /*
+ * Check if certificate is revoked
+ */
+ if( x509_crt_revoked( crt, crl_list ) )
+ {
+ flags |= BADCERT_REVOKED;
+ break;
+ }
+
+ crl_list = crl_list->next;
+ }
+ return( flags );
+}
+#endif /* POLARSSL_X509_CRL_PARSE_C */
+
+/*
+ * Like memcmp, but case-insensitive and always returns -1 if different
+ */
+static int x509_memcasecmp( const void *s1, const void *s2, size_t len )
+{
+ size_t i;
+ unsigned char diff;
+ const unsigned char *n1 = s1, *n2 = s2;
+
+ for( i = 0; i < len; i++ )
+ {
+ diff = n1[i] ^ n2[i];
+
+ if( diff == 0 )
+ continue;
+
+ if( diff == 32 &&
+ ( ( n1[i] >= 'a' && n1[i] <= 'z' ) ||
+ ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) )
+ {
+ continue;
+ }
+
+ return( -1 );
+ }
+
+ return( 0 );
+}
+
+/*
+ * Return 1 if match, 0 if not
+ * TODO: inverted return value!
+ */
+static int x509_wildcard_verify( const char *cn, x509_buf *name )
+{
+ size_t i;
+ size_t cn_idx = 0, cn_len = strlen( cn );
+
+ if( name->len < 3 || name->p[0] != '*' || name->p[1] != '.' )
+ return( 0 );
+
+ for( i = 0; i < cn_len; ++i )
+ {
+ if( cn[i] == '.' )
+ {
+ cn_idx = i;
+ break;
+ }
+ }
+
+ if( cn_idx == 0 )
+ return( 0 );
+
+ if( cn_len - cn_idx == name->len - 1 &&
+ x509_memcasecmp( name->p + 1, cn + cn_idx, name->len - 1 ) == 0 )
+ {
+ return( 1 );
+ }
+
+ return( 0 );
+}
+
+/*
+ * Compare two X.509 strings, case-insensitive, and allowing for some encoding
+ * variations (but not all).
+ *
+ * Return 0 if equal, -1 otherwise.
+ */
+static int x509_string_cmp( const x509_buf *a, const x509_buf *b )
+{
+ if( a->tag == b->tag &&
+ a->len == b->len &&
+ memcmp( a->p, b->p, b->len ) == 0 )
+ {
+ return( 0 );
+ }
+
+ if( ( a->tag == ASN1_UTF8_STRING || a->tag == ASN1_PRINTABLE_STRING ) &&
+ ( b->tag == ASN1_UTF8_STRING || b->tag == ASN1_PRINTABLE_STRING ) &&
+ a->len == b->len &&
+ x509_memcasecmp( a->p, b->p, b->len ) == 0 )
+ {
+ return( 0 );
+ }
+
+ return( -1 );
+}
+
+/*
+ * Compare two X.509 Names (aka rdnSequence).
+ *
+ * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
+ * we sometimes return unequal when the full algorithm would return equal,
+ * but never the other way. (In particular, we don't do Unicode normalisation
+ * or space folding.)
+ *
+ * Return 0 if equal, -1 otherwise.
+ */
+static int x509_name_cmp( const x509_name *a, const x509_name *b )
+{
+ /* Avoid recursion, it might not be optimised by the compiler */
+ while( a != NULL || b != NULL )
+ {
+ if( a == NULL || b == NULL )
+ return( -1 );
+
+ /* type */
+ if( a->oid.tag != b->oid.tag ||
+ a->oid.len != b->oid.len ||
+ memcmp( a->oid.p, b->oid.p, b->oid.len ) != 0 )
+ {
+ return( -1 );
+ }
+
+ /* value */
+ if( x509_string_cmp( &a->val, &b->val ) != 0 )
+ return( -1 );
+
+ /* structure of the list of sets */
+ if( a->next_merged != b->next_merged )
+ return( -1 );
+
+ a = a->next;
+ b = b->next;
+ }
+
+ /* a == NULL == b */
+ return( 0 );
+}
+
+/*
+ * Check if 'parent' is a suitable parent (signing CA) for 'child'.
+ * Return 0 if yes, -1 if not.
+ *
+ * top means parent is a locally-trusted certificate
+ * bottom means child is the end entity cert
+ */
+static int x509_crt_check_parent( const x509_crt *child,
+ const x509_crt *parent,
+ int top, int bottom )
+{
+ int need_ca_bit;
+
+ /* Parent must be the issuer */
+ if( x509_name_cmp( &child->issuer, &parent->subject ) != 0 )
+ return( -1 );
+
+ /* Parent must have the basicConstraints CA bit set as a general rule */
+ need_ca_bit = 1;
+
+ /* Exception: v1/v2 certificates that are locally trusted. */
+ if( top && parent->version < 3 )
+ need_ca_bit = 0;
+
+ /* Exception: self-signed end-entity certs that are locally trusted. */
+ if( top && bottom &&
+ child->raw.len == parent->raw.len &&
+ memcmp( child->raw.p, parent->raw.p, child->raw.len ) == 0 )
+ {
+ need_ca_bit = 0;
+ }
+
+ if( need_ca_bit && ! parent->ca_istrue )
+ return( -1 );
+
+#if defined(POLARSSL_X509_CHECK_KEY_USAGE)
+ if( need_ca_bit &&
+ x509_crt_check_key_usage( parent, KU_KEY_CERT_SIGN ) != 0 )
+ {
+ return( -1 );
+ }
+#endif
+
+ return( 0 );
+}
+
+static int x509_crt_verify_top(
+ x509_crt *child, x509_crt *trust_ca,
+ x509_crl *ca_crl, int path_cnt, int *flags,
+ int (*f_vrfy)(void *, x509_crt *, int, int *),
+ void *p_vrfy )
+{
+ int ret;
+ int ca_flags = 0, check_path_cnt;
+ unsigned char hash[POLARSSL_MD_MAX_SIZE];
+ const md_info_t *md_info;
+
+ if( x509_time_expired( &child->valid_to ) )
+ *flags |= BADCERT_EXPIRED;
+
+ if( x509_time_future( &child->valid_from ) )
+ *flags |= BADCERT_FUTURE;
+
+ /*
+ * Child is the top of the chain. Check against the trust_ca list.
+ */
+ *flags |= BADCERT_NOT_TRUSTED;
+
+ md_info = md_info_from_type( child->sig_md );
+ if( md_info == NULL )
+ {
+ /*
+ * Cannot check 'unknown', no need to try any CA
+ */
+ trust_ca = NULL;
+ }
+ else
+ md( md_info, child->tbs.p, child->tbs.len, hash );
+
+ for( /* trust_ca */ ; trust_ca != NULL; trust_ca = trust_ca->next )
+ {
+ if( x509_crt_check_parent( child, trust_ca, 1, path_cnt == 0 ) != 0 )
+ continue;
+
+ check_path_cnt = path_cnt + 1;
+
+ /*
+ * Reduce check_path_cnt to check against if top of the chain is
+ * the same as the trusted CA
+ */
+ if( child->subject_raw.len == trust_ca->subject_raw.len &&
+ memcmp( child->subject_raw.p, trust_ca->subject_raw.p,
+ child->issuer_raw.len ) == 0 )
+ {
+ check_path_cnt--;
+ }
+
+ if( trust_ca->max_pathlen > 0 &&
+ trust_ca->max_pathlen < check_path_cnt )
+ {
+ continue;
+ }
+
+ if( pk_verify_ext( child->sig_pk, child->sig_opts, &trust_ca->pk,
+ child->sig_md, hash, md_info->size,
+ child->sig.p, child->sig.len ) != 0 )
+ {
+ continue;
+ }
+
+ /*
+ * Top of chain is signed by a trusted CA
+ */
+ *flags &= ~BADCERT_NOT_TRUSTED;
+ break;
+ }
+
+ /*
+ * If top of chain is not the same as the trusted CA send a verify request
+ * to the callback for any issues with validity and CRL presence for the
+ * trusted CA certificate.
+ */
+ if( trust_ca != NULL &&
+ ( child->subject_raw.len != trust_ca->subject_raw.len ||
+ memcmp( child->subject_raw.p, trust_ca->subject_raw.p,
+ child->issuer_raw.len ) != 0 ) )
+ {
+#if defined(POLARSSL_X509_CRL_PARSE_C)
+ /* Check trusted CA's CRL for the chain's top crt */
+ *flags |= x509_crt_verifycrl( child, trust_ca, ca_crl );
+#else
+ ((void) ca_crl);
+#endif
+
+ if( x509_time_expired( &trust_ca->valid_to ) )
+ ca_flags |= BADCERT_EXPIRED;
+
+ if( x509_time_future( &trust_ca->valid_from ) )
+ ca_flags |= BADCERT_FUTURE;
+
+ if( NULL != f_vrfy )
+ {
+ if( ( ret = f_vrfy( p_vrfy, trust_ca, path_cnt + 1,
+ &ca_flags ) ) != 0 )
+ {
+ return( ret );
+ }
+ }
+ }
+
+ /* Call callback on top cert */
+ if( NULL != f_vrfy )
+ {
+ if( ( ret = f_vrfy( p_vrfy, child, path_cnt, flags ) ) != 0 )
+ return( ret );
+ }
+
+ *flags |= ca_flags;
+
+ return( 0 );
+}
+
+static int x509_crt_verify_child(
+ x509_crt *child, x509_crt *parent, x509_crt *trust_ca,
+ x509_crl *ca_crl, int path_cnt, int *flags,
+ int (*f_vrfy)(void *, x509_crt *, int, int *),
+ void *p_vrfy )
+{
+ int ret;
+ int parent_flags = 0;
+ unsigned char hash[POLARSSL_MD_MAX_SIZE];
+ x509_crt *grandparent;
+ const md_info_t *md_info;
+
+ /* path_cnt is 0 for the first intermediate CA */
+ if( 1 + path_cnt > POLARSSL_X509_MAX_INTERMEDIATE_CA )
+ {
+ *flags |= BADCERT_NOT_TRUSTED;
+ return( POLARSSL_ERR_X509_CERT_VERIFY_FAILED );
+ }
+
+ if( x509_time_expired( &child->valid_to ) )
+ *flags |= BADCERT_EXPIRED;
+
+ if( x509_time_future( &child->valid_from ) )
+ *flags |= BADCERT_FUTURE;
+
+ md_info = md_info_from_type( child->sig_md );
+ if( md_info == NULL )
+ {
+ /*
+ * Cannot check 'unknown' hash
+ */
+ *flags |= BADCERT_NOT_TRUSTED;
+ }
+ else
+ {
+ md( md_info, child->tbs.p, child->tbs.len, hash );
+
+ if( pk_verify_ext( child->sig_pk, child->sig_opts, &parent->pk,
+ child->sig_md, hash, md_info->size,
+ child->sig.p, child->sig.len ) != 0 )
+ {
+ *flags |= BADCERT_NOT_TRUSTED;
+ }
+ }
+
+#if defined(POLARSSL_X509_CRL_PARSE_C)
+ /* Check trusted CA's CRL for the given crt */
+ *flags |= x509_crt_verifycrl(child, parent, ca_crl);
+#endif
+
+ /* Look for a grandparent upwards the chain */
+ for( grandparent = parent->next;
+ grandparent != NULL;
+ grandparent = grandparent->next )
+ {
+ if( x509_crt_check_parent( parent, grandparent,
+ 0, path_cnt == 0 ) == 0 )
+ break;
+ }
+
+ /* Is our parent part of the chain or at the top? */
+ if( grandparent != NULL )
+ {
+ ret = x509_crt_verify_child( parent, grandparent, trust_ca, ca_crl,
+ path_cnt + 1, &parent_flags, f_vrfy, p_vrfy );
+ if( ret != 0 )
+ return( ret );
+ }
+ else
+ {
+ ret = x509_crt_verify_top( parent, trust_ca, ca_crl,
+ path_cnt + 1, &parent_flags, f_vrfy, p_vrfy );
+ if( ret != 0 )
+ return( ret );
+ }
+
+ /* child is verified to be a child of the parent, call verify callback */
+ if( NULL != f_vrfy )
+ if( ( ret = f_vrfy( p_vrfy, child, path_cnt, flags ) ) != 0 )
+ return( ret );
+
+ *flags |= parent_flags;
+
+ return( 0 );
+}
+
+/*
+ * Verify the certificate validity
+ */
+int x509_crt_verify( x509_crt *crt,
+ x509_crt *trust_ca,
+ x509_crl *ca_crl,
+ const char *cn, int *flags,
+ int (*f_vrfy)(void *, x509_crt *, int, int *),
+ void *p_vrfy )
+{
+ size_t cn_len;
+ int ret;
+ int pathlen = 0;
+ x509_crt *parent;
+ x509_name *name;
+ x509_sequence *cur = NULL;
+
+ *flags = 0;
+
+ if( cn != NULL )
+ {
+ name = &crt->subject;
+ cn_len = strlen( cn );
+
+ if( crt->ext_types & EXT_SUBJECT_ALT_NAME )
+ {
+ cur = &crt->subject_alt_names;
+
+ while( cur != NULL )
+ {
+ if( cur->buf.len == cn_len &&
+ x509_memcasecmp( cn, cur->buf.p, cn_len ) == 0 )
+ break;
+
+ if( cur->buf.len > 2 &&
+ memcmp( cur->buf.p, "*.", 2 ) == 0 &&
+ x509_wildcard_verify( cn, &cur->buf ) )
+ break;
+
+ cur = cur->next;
+ }
+
+ if( cur == NULL )
+ *flags |= BADCERT_CN_MISMATCH;
+ }
+ else
+ {
+ while( name != NULL )
+ {
+ if( OID_CMP( OID_AT_CN, &name->oid ) )
+ {
+ if( name->val.len == cn_len &&
+ x509_memcasecmp( name->val.p, cn, cn_len ) == 0 )
+ break;
+
+ if( name->val.len > 2 &&
+ memcmp( name->val.p, "*.", 2 ) == 0 &&
+ x509_wildcard_verify( cn, &name->val ) )
+ break;
+ }
+
+ name = name->next;
+ }
+
+ if( name == NULL )
+ *flags |= BADCERT_CN_MISMATCH;
+ }
+ }
+
+ /* Look for a parent upwards the chain */
+ for( parent = crt->next; parent != NULL; parent = parent->next )
+ {
+ if( x509_crt_check_parent( crt, parent, 0, pathlen == 0 ) == 0 )
+ break;
+ }
+
+ /* Are we part of the chain or at the top? */
+ if( parent != NULL )
+ {
+ ret = x509_crt_verify_child( crt, parent, trust_ca, ca_crl,
+ pathlen, flags, f_vrfy, p_vrfy );
+ if( ret != 0 )
+ return( ret );
+ }
+ else
+ {
+ ret = x509_crt_verify_top( crt, trust_ca, ca_crl,
+ pathlen, flags, f_vrfy, p_vrfy );
+ if( ret != 0 )
+ return( ret );
+ }
+
+ if( *flags != 0 )
+ return( POLARSSL_ERR_X509_CERT_VERIFY_FAILED );
+
+ return( 0 );
+}
+
+/*
+ * Initialize a certificate chain
+ */
+void x509_crt_init( x509_crt *crt )
+{
+ memset( crt, 0, sizeof(x509_crt) );
+}
+
+/*
+ * Unallocate all certificate data
+ */
+void x509_crt_free( x509_crt *crt )
+{
+ x509_crt *cert_cur = crt;
+ x509_crt *cert_prv;
+ x509_name *name_cur;
+ x509_name *name_prv;
+ x509_sequence *seq_cur;
+ x509_sequence *seq_prv;
+
+ if( crt == NULL )
+ return;
+
+ do
+ {
+ pk_free( &cert_cur->pk );
+
+#if defined(POLARSSL_X509_RSASSA_PSS_SUPPORT)
+ polarssl_free( cert_cur->sig_opts );
+#endif
+
+ name_cur = cert_cur->issuer.next;
+ while( name_cur != NULL )
+ {
+ name_prv = name_cur;
+ name_cur = name_cur->next;
+ polarssl_zeroize( name_prv, sizeof( x509_name ) );
+ polarssl_free( name_prv );
+ }
+
+ name_cur = cert_cur->subject.next;
+ while( name_cur != NULL )
+ {
+ name_prv = name_cur;
+ name_cur = name_cur->next;
+ polarssl_zeroize( name_prv, sizeof( x509_name ) );
+ polarssl_free( name_prv );
+ }
+
+ seq_cur = cert_cur->ext_key_usage.next;
+ while( seq_cur != NULL )
+ {
+ seq_prv = seq_cur;
+ seq_cur = seq_cur->next;
+ polarssl_zeroize( seq_prv, sizeof( x509_sequence ) );
+ polarssl_free( seq_prv );
+ }
+
+ seq_cur = cert_cur->subject_alt_names.next;
+ while( seq_cur != NULL )
+ {
+ seq_prv = seq_cur;
+ seq_cur = seq_cur->next;
+ polarssl_zeroize( seq_prv, sizeof( x509_sequence ) );
+ polarssl_free( seq_prv );
+ }
+
+ if( cert_cur->raw.p != NULL )
+ {
+ polarssl_zeroize( cert_cur->raw.p, cert_cur->raw.len );
+ polarssl_free( cert_cur->raw.p );
+ }
+
+ cert_cur = cert_cur->next;
+ }
+ while( cert_cur != NULL );
+
+ cert_cur = crt;
+ do
+ {
+ cert_prv = cert_cur;
+ cert_cur = cert_cur->next;
+
+ polarssl_zeroize( cert_prv, sizeof( x509_crt ) );
+ if( cert_prv != crt )
+ polarssl_free( cert_prv );
+ }
+ while( cert_cur != NULL );
+}
+
+#endif /* POLARSSL_X509_CRT_PARSE_C */
+