mbed TLS Build
Dependents: Encrypt_Decrypt1 mbed_blink_tls encrypt encrypt
Diff: library/pkwrite.c
- Revision:
- 0:cdf462088d13
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/library/pkwrite.c Thu Jan 05 00:18:44 2017 +0000 @@ -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 */