| /* |
| * 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_mpi T; |
| |
| mbedtls_mpi_init( &T ); |
| |
| /* Export E */ |
| if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL, NULL, NULL, &T ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( p, start, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| /* Export N */ |
| if ( ( ret = mbedtls_rsa_export( rsa, &T, NULL, NULL, NULL, NULL ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( p, start, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| end_of_export: |
| |
| mbedtls_mpi_free( &T ); |
| if( ret < 0 ) |
| return( ret ); |
| |
| 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_mpi T; /* Temporary holding the exported parameters */ |
| mbedtls_rsa_context *rsa = mbedtls_pk_rsa( *key ); |
| |
| /* |
| * Export the parameters one after another to avoid simultaneous copies. |
| */ |
| |
| mbedtls_mpi_init( &T ); |
| |
| /* Export QP */ |
| if( ( ret = mbedtls_rsa_export_crt( rsa, NULL, NULL, &T ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| /* Export DQ */ |
| if( ( ret = mbedtls_rsa_export_crt( rsa, NULL, &T, NULL ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| /* Export DP */ |
| if( ( ret = mbedtls_rsa_export_crt( rsa, &T, NULL, NULL ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| /* Export Q */ |
| if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL, |
| &T, NULL, NULL ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| /* Export P */ |
| if ( ( ret = mbedtls_rsa_export( rsa, NULL, &T, |
| NULL, NULL, NULL ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| /* Export D */ |
| if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL, |
| NULL, &T, NULL ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| /* Export E */ |
| if ( ( ret = mbedtls_rsa_export( rsa, NULL, NULL, |
| NULL, NULL, &T ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| /* Export N */ |
| if ( ( ret = mbedtls_rsa_export( rsa, &T, NULL, |
| NULL, NULL, NULL ) ) != 0 || |
| ( ret = mbedtls_asn1_write_mpi( &c, buf, &T ) ) < 0 ) |
| goto end_of_export; |
| len += ret; |
| |
| end_of_export: |
| |
| mbedtls_mpi_free( &T ); |
| if( ret < 0 ) |
| return( ret ); |
| |
| 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 */ |