sandbox
mbedtls ported to mbed-classic
Fork of
mbedtls
by 
Christopher Haster
Diff: source/pkwrite.c
- Revision:
- 1:24750b9ad5ef
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/source/pkwrite.c Fri Jan 22 16:44:49 2016 -0600
@@ -0,0 +1,439 @@
+/*
+ * Public Key layer for writing key files and structures
+ *
+ * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_PK_WRITE_C)
+
+#include "mbedtls/pk.h"
+#include "mbedtls/asn1write.h"
+#include "mbedtls/oid.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_RSA_C)
+#include "mbedtls/rsa.h"
+#endif
+#if defined(MBEDTLS_ECP_C)
+#include "mbedtls/ecp.h"
+#endif
+#if defined(MBEDTLS_ECDSA_C)
+#include "mbedtls/ecdsa.h"
+#endif
+#if defined(MBEDTLS_PEM_WRITE_C)
+#include "mbedtls/pem.h"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdlib.h>
+#define mbedtls_calloc calloc
+#define mbedtls_free free
+#endif
+
+#if defined(MBEDTLS_RSA_C)
+/*
+ * RSAPublicKey ::= SEQUENCE {
+ * modulus INTEGER, -- n
+ * publicExponent INTEGER -- e
+ * }
+ */
+static int pk_write_rsa_pubkey( unsigned char **p, unsigned char *start,
+ mbedtls_rsa_context *rsa )
+{
+ int ret;
+ size_t len = 0;
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( p, start, &rsa->E ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( p, start, &rsa->N ) );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_CONSTRUCTED |
+ MBEDTLS_ASN1_SEQUENCE ) );
+
+ return( (int) len );
+}
+#endif /* MBEDTLS_RSA_C */
+
+#if defined(MBEDTLS_ECP_C)
+/*
+ * EC public key is an EC point
+ */
+static int pk_write_ec_pubkey( unsigned char **p, unsigned char *start,
+ mbedtls_ecp_keypair *ec )
+{
+ int ret;
+ size_t len = 0;
+ unsigned char buf[MBEDTLS_ECP_MAX_PT_LEN];
+
+ if( ( ret = mbedtls_ecp_point_write_binary( &ec->grp, &ec->Q,
+ MBEDTLS_ECP_PF_UNCOMPRESSED,
+ &len, buf, sizeof( buf ) ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ if( *p < start || (size_t)( *p - start ) < len )
+ return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+
+ *p -= len;
+ memcpy( *p, buf, len );
+
+ return( (int) len );
+}
+
+/*
+ * ECParameters ::= CHOICE {
+ * namedCurve OBJECT IDENTIFIER
+ * }
+ */
+static int pk_write_ec_param( unsigned char **p, unsigned char *start,
+ mbedtls_ecp_keypair *ec )
+{
+ int ret;
+ size_t len = 0;
+ const char *oid;
+ size_t oid_len;
+
+ if( ( ret = mbedtls_oid_get_oid_by_ec_grp( ec->grp.id, &oid, &oid_len ) ) != 0 )
+ return( ret );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
+
+ return( (int) len );
+}
+#endif /* MBEDTLS_ECP_C */
+
+int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
+ const mbedtls_pk_context *key )
+{
+ int ret;
+ size_t len = 0;
+
+#if defined(MBEDTLS_RSA_C)
+ if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
+ MBEDTLS_ASN1_CHK_ADD( len, pk_write_rsa_pubkey( p, start, mbedtls_pk_rsa( *key ) ) );
+ else
+#endif
+#if defined(MBEDTLS_ECP_C)
+ if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
+ MBEDTLS_ASN1_CHK_ADD( len, pk_write_ec_pubkey( p, start, mbedtls_pk_ec( *key ) ) );
+ else
+#endif
+ return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
+
+ return( (int) len );
+}
+
+int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
+{
+ int ret;
+ unsigned char *c;
+ size_t len = 0, par_len = 0, oid_len;
+ const char *oid;
+
+ c = buf + size;
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, key ) );
+
+ if( c - buf < 1 )
+ return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+
+ /*
+ * SubjectPublicKeyInfo ::= SEQUENCE {
+ * algorithm AlgorithmIdentifier,
+ * subjectPublicKey BIT STRING }
+ */
+ *--c = 0;
+ len += 1;
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );
+
+ if( ( ret = mbedtls_oid_get_oid_by_pk_alg( mbedtls_pk_get_type( key ),
+ &oid, &oid_len ) ) != 0 )
+ {
+ return( ret );
+ }
+
+#if defined(MBEDTLS_ECP_C)
+ if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
+ {
+ MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, mbedtls_pk_ec( *key ) ) );
+ }
+#endif
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, buf, oid, oid_len,
+ par_len ) );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
+ MBEDTLS_ASN1_SEQUENCE ) );
+
+ return( (int) len );
+}
+
+int mbedtls_pk_write_key_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
+{
+ int ret;
+ unsigned char *c = buf + size;
+ size_t len = 0;
+
+#if defined(MBEDTLS_RSA_C)
+ if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
+ {
+ mbedtls_rsa_context *rsa = mbedtls_pk_rsa( *key );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->QP ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->DQ ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->DP ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->Q ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->P ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->D ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->E ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &rsa->N ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 0 ) );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
+ MBEDTLS_ASN1_SEQUENCE ) );
+ }
+ else
+#endif /* MBEDTLS_RSA_C */
+#if defined(MBEDTLS_ECP_C)
+ if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
+ {
+ mbedtls_ecp_keypair *ec = mbedtls_pk_ec( *key );
+ size_t pub_len = 0, par_len = 0;
+
+ /*
+ * RFC 5915, or SEC1 Appendix C.4
+ *
+ * ECPrivateKey ::= SEQUENCE {
+ * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
+ * privateKey OCTET STRING,
+ * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
+ * publicKey [1] BIT STRING OPTIONAL
+ * }
+ */
+
+ /* publicKey */
+ MBEDTLS_ASN1_CHK_ADD( pub_len, pk_write_ec_pubkey( &c, buf, ec ) );
+
+ if( c - buf < 1 )
+ return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+ *--c = 0;
+ pub_len += 1;
+
+ MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) );
+ MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_BIT_STRING ) );
+
+ MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_len( &c, buf, pub_len ) );
+ MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_asn1_write_tag( &c, buf,
+ MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) );
+ len += pub_len;
+
+ /* parameters */
+ MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, ec ) );
+
+ MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_len( &c, buf, par_len ) );
+ MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_tag( &c, buf,
+ MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) );
+ len += par_len;
+
+ /* privateKey: write as MPI then fix tag */
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, buf, &ec->d ) );
+ *c = MBEDTLS_ASN1_OCTET_STRING;
+
+ /* version */
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, 1 ) );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED |
+ MBEDTLS_ASN1_SEQUENCE ) );
+ }
+ else
+#endif /* MBEDTLS_ECP_C */
+ return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
+
+ return( (int) len );
+}
+
+#if defined(MBEDTLS_PEM_WRITE_C)
+
+#define PEM_BEGIN_PUBLIC_KEY "-----BEGIN PUBLIC KEY-----\n"
+#define PEM_END_PUBLIC_KEY "-----END PUBLIC KEY-----\n"
+
+#define PEM_BEGIN_PRIVATE_KEY_RSA "-----BEGIN RSA PRIVATE KEY-----\n"
+#define PEM_END_PRIVATE_KEY_RSA "-----END RSA PRIVATE KEY-----\n"
+#define PEM_BEGIN_PRIVATE_KEY_EC "-----BEGIN EC PRIVATE KEY-----\n"
+#define PEM_END_PRIVATE_KEY_EC "-----END EC PRIVATE KEY-----\n"
+
+/*
+ * Max sizes of key per types. Shown as tag + len (+ content).
+ */
+
+#if defined(MBEDTLS_RSA_C)
+/*
+ * RSA public keys:
+ * SubjectPublicKeyInfo ::= SEQUENCE { 1 + 3
+ * algorithm AlgorithmIdentifier, 1 + 1 (sequence)
+ * + 1 + 1 + 9 (rsa oid)
+ * + 1 + 1 (params null)
+ * subjectPublicKey BIT STRING } 1 + 3 + (1 + below)
+ * RSAPublicKey ::= SEQUENCE { 1 + 3
+ * modulus INTEGER, -- n 1 + 3 + MPI_MAX + 1
+ * publicExponent INTEGER -- e 1 + 3 + MPI_MAX + 1
+ * }
+ */
+#define RSA_PUB_DER_MAX_BYTES 38 + 2 * MBEDTLS_MPI_MAX_SIZE
+
+/*
+ * RSA private keys:
+ * RSAPrivateKey ::= SEQUENCE { 1 + 3
+ * version Version, 1 + 1 + 1
+ * modulus INTEGER, 1 + 3 + MPI_MAX + 1
+ * publicExponent INTEGER, 1 + 3 + MPI_MAX + 1
+ * privateExponent INTEGER, 1 + 3 + MPI_MAX + 1
+ * prime1 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
+ * prime2 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
+ * exponent1 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
+ * exponent2 INTEGER, 1 + 3 + MPI_MAX / 2 + 1
+ * coefficient INTEGER, 1 + 3 + MPI_MAX / 2 + 1
+ * otherPrimeInfos OtherPrimeInfos OPTIONAL 0 (not supported)
+ * }
+ */
+#define MPI_MAX_SIZE_2 MBEDTLS_MPI_MAX_SIZE / 2 + \
+ MBEDTLS_MPI_MAX_SIZE % 2
+#define RSA_PRV_DER_MAX_BYTES 47 + 3 * MBEDTLS_MPI_MAX_SIZE \
+ + 5 * MPI_MAX_SIZE_2
+
+#else /* MBEDTLS_RSA_C */
+
+#define RSA_PUB_DER_MAX_BYTES 0
+#define RSA_PRV_DER_MAX_BYTES 0
+
+#endif /* MBEDTLS_RSA_C */
+
+#if defined(MBEDTLS_ECP_C)
+/*
+ * EC public keys:
+ * SubjectPublicKeyInfo ::= SEQUENCE { 1 + 2
+ * algorithm AlgorithmIdentifier, 1 + 1 (sequence)
+ * + 1 + 1 + 7 (ec oid)
+ * + 1 + 1 + 9 (namedCurve oid)
+ * subjectPublicKey BIT STRING 1 + 2 + 1 [1]
+ * + 1 (point format) [1]
+ * + 2 * ECP_MAX (coords) [1]
+ * }
+ */
+#define ECP_PUB_DER_MAX_BYTES 30 + 2 * MBEDTLS_ECP_MAX_BYTES
+
+/*
+ * EC private keys:
+ * ECPrivateKey ::= SEQUENCE { 1 + 2
+ * version INTEGER , 1 + 1 + 1
+ * privateKey OCTET STRING, 1 + 1 + ECP_MAX
+ * parameters [0] ECParameters OPTIONAL, 1 + 1 + (1 + 1 + 9)
+ * publicKey [1] BIT STRING OPTIONAL 1 + 2 + [1] above
+ * }
+ */
+#define ECP_PRV_DER_MAX_BYTES 29 + 3 * MBEDTLS_ECP_MAX_BYTES
+
+#else /* MBEDTLS_ECP_C */
+
+#define ECP_PUB_DER_MAX_BYTES 0
+#define ECP_PRV_DER_MAX_BYTES 0
+
+#endif /* MBEDTLS_ECP_C */
+
+#define PUB_DER_MAX_BYTES RSA_PUB_DER_MAX_BYTES > ECP_PUB_DER_MAX_BYTES ? \
+ RSA_PUB_DER_MAX_BYTES : ECP_PUB_DER_MAX_BYTES
+#define PRV_DER_MAX_BYTES RSA_PRV_DER_MAX_BYTES > ECP_PRV_DER_MAX_BYTES ? \
+ RSA_PRV_DER_MAX_BYTES : ECP_PRV_DER_MAX_BYTES
+
+int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
+{
+ int ret;
+ unsigned char output_buf[PUB_DER_MAX_BYTES];
+ size_t olen = 0;
+
+ if( ( ret = mbedtls_pk_write_pubkey_der( key, output_buf,
+ sizeof(output_buf) ) ) < 0 )
+ {
+ return( ret );
+ }
+
+ if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_PUBLIC_KEY, PEM_END_PUBLIC_KEY,
+ output_buf + sizeof(output_buf) - ret,
+ ret, buf, size, &olen ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ return( 0 );
+}
+
+int mbedtls_pk_write_key_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
+{
+ int ret;
+ unsigned char output_buf[PRV_DER_MAX_BYTES];
+ const char *begin, *end;
+ size_t olen = 0;
+
+ if( ( ret = mbedtls_pk_write_key_der( key, output_buf, sizeof(output_buf) ) ) < 0 )
+ return( ret );
+
+#if defined(MBEDTLS_RSA_C)
+ if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
+ {
+ begin = PEM_BEGIN_PRIVATE_KEY_RSA;
+ end = PEM_END_PRIVATE_KEY_RSA;
+ }
+ else
+#endif
+#if defined(MBEDTLS_ECP_C)
+ if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
+ {
+ begin = PEM_BEGIN_PRIVATE_KEY_EC;
+ end = PEM_END_PRIVATE_KEY_EC;
+ }
+ else
+#endif
+ return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
+
+ if( ( ret = mbedtls_pem_write_buffer( begin, end,
+ output_buf + sizeof(output_buf) - ret,
+ ret, buf, size, &olen ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ return( 0 );
+}
+#endif /* MBEDTLS_PEM_WRITE_C */
+
+#endif /* MBEDTLS_PK_WRITE_C */