| /* |
| * Public Key layer for writing key files and structures |
| * |
| * Copyright The Mbed TLS Contributors |
| * 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. |
| */ |
| |
| #include "common.h" |
| |
| #if defined(MBEDTLS_PK_WRITE_C) |
| |
| #include "mbedtls/pk.h" |
| #include "mbedtls/asn1write.h" |
| #include "mbedtls/oid.h" |
| #include "mbedtls/platform_util.h" |
| #include "mbedtls/error.h" |
| |
| #include <string.h> |
| |
| #if defined(MBEDTLS_RSA_C) |
| #include "mbedtls/rsa.h" |
| #endif |
| #if defined(MBEDTLS_ECP_C) |
| #include "mbedtls/bignum.h" |
| #include "mbedtls/ecp.h" |
| #include "mbedtls/platform_util.h" |
| #endif |
| #if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECP_C) |
| #include "pkwrite.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_USE_PSA_CRYPTO) |
| #include "psa/crypto.h" |
| #include "mbedtls/psa_util.h" |
| #endif |
| #include "mbedtls/platform.h" |
| |
| #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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| 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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| 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 = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| 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 ); |
| } |
| |
| /* |
| * privateKey OCTET STRING -- always of length ceil(log2(n)/8) |
| */ |
| static int pk_write_ec_private( unsigned char **p, unsigned char *start, |
| mbedtls_ecp_keypair *ec ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| size_t byte_length = ( ec->grp.pbits + 7 ) / 8; |
| unsigned char tmp[MBEDTLS_ECP_MAX_BYTES]; |
| |
| ret = mbedtls_ecp_write_key( ec, tmp, byte_length ); |
| if( ret != 0 ) |
| goto exit; |
| ret = mbedtls_asn1_write_octet_string( p, start, tmp, byte_length ); |
| |
| exit: |
| mbedtls_platform_zeroize( tmp, byte_length ); |
| return( ret ); |
| } |
| #endif /* MBEDTLS_ECP_C */ |
| |
| int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start, |
| const mbedtls_pk_context *key ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| 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 |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_OPAQUE ) |
| { |
| size_t buffer_size; |
| mbedtls_svc_key_id_t* key_id = (mbedtls_svc_key_id_t*) key->pk_ctx; |
| |
| if ( *p < start ) |
| return( MBEDTLS_ERR_PK_BAD_INPUT_DATA ); |
| |
| buffer_size = (size_t)( *p - start ); |
| if ( psa_export_public_key( *key_id, start, buffer_size, &len ) |
| != PSA_SUCCESS ) |
| { |
| return( MBEDTLS_ERR_PK_BAD_INPUT_DATA ); |
| } |
| else |
| { |
| *p -= len; |
| memmove( *p, start, len ); |
| } |
| } |
| else |
| #endif /* MBEDTLS_USE_PSA_CRYPTO */ |
| return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE ); |
| |
| return( (int) len ); |
| } |
| |
| int mbedtls_pk_write_pubkey_der( const mbedtls_pk_context *key, unsigned char *buf, size_t size ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *c; |
| size_t len = 0, par_len = 0, oid_len; |
| mbedtls_pk_type_t pk_type; |
| const char *oid; |
| |
| if( size == 0 ) |
| return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| 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 ) ); |
| |
| pk_type = mbedtls_pk_get_type( key ); |
| #if defined(MBEDTLS_ECP_C) |
| if( pk_type == MBEDTLS_PK_ECKEY ) |
| { |
| MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, mbedtls_pk_ec( *key ) ) ); |
| } |
| #endif |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| if( pk_type == MBEDTLS_PK_OPAQUE ) |
| { |
| psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; |
| psa_key_type_t key_type; |
| mbedtls_svc_key_id_t key_id; |
| psa_ecc_family_t curve; |
| size_t bits; |
| |
| key_id = *((mbedtls_svc_key_id_t*) key->pk_ctx ); |
| if( PSA_SUCCESS != psa_get_key_attributes( key_id, &attributes ) ) |
| return( MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED ); |
| key_type = psa_get_key_type( &attributes ); |
| bits = psa_get_key_bits( &attributes ); |
| psa_reset_key_attributes( &attributes ); |
| |
| if( PSA_KEY_TYPE_IS_ECC_KEY_PAIR( key_type ) ) |
| { |
| curve = PSA_KEY_TYPE_ECC_GET_FAMILY( key_type ); |
| if( curve == 0 ) |
| return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE ); |
| |
| ret = mbedtls_psa_get_ecc_oid_from_id( curve, bits, |
| &oid, &oid_len ); |
| if( ret != 0 ) |
| return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE ); |
| |
| /* Write EC algorithm parameters; that's akin |
| * to pk_write_ec_param() above. */ |
| MBEDTLS_ASN1_CHK_ADD( par_len, mbedtls_asn1_write_oid( &c, buf, |
| oid, |
| oid_len ) ); |
| |
| /* The rest of the function works as for legacy EC contexts. */ |
| pk_type = MBEDTLS_PK_ECKEY; |
| } |
| else if( PSA_KEY_TYPE_IS_RSA( key_type ) ) |
| { |
| /* The rest of the function works as for legacy RSA contexts. */ |
| pk_type = MBEDTLS_PK_RSA; |
| } |
| else |
| { |
| return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE ); |
| } |
| } |
| #endif /* MBEDTLS_USE_PSA_CRYPTO */ |
| |
| if( ( ret = mbedtls_oid_get_oid_by_pk_alg( pk_type, &oid, |
| &oid_len ) ) != 0 ) |
| { |
| return( ret ); |
| } |
| |
| 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( const mbedtls_pk_context *key, unsigned char *buf, size_t size ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *c; |
| size_t len = 0; |
| |
| if( size == 0 ) |
| return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); |
| |
| c = buf + size; |
| |
| #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 */ |
| MBEDTLS_ASN1_CHK_ADD( len, pk_write_ec_private( &c, buf, ec ) ); |
| |
| /* 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" |
| |
| #define PUB_DER_MAX_BYTES \ |
| ( MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES > MBEDTLS_PK_ECP_PUB_DER_MAX_BYTES ? \ |
| MBEDTLS_PK_RSA_PUB_DER_MAX_BYTES : MBEDTLS_PK_ECP_PUB_DER_MAX_BYTES ) |
| #define PRV_DER_MAX_BYTES \ |
| ( MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES > MBEDTLS_PK_ECP_PRV_DER_MAX_BYTES ? \ |
| MBEDTLS_PK_RSA_PRV_DER_MAX_BYTES : MBEDTLS_PK_ECP_PRV_DER_MAX_BYTES ) |
| |
| int mbedtls_pk_write_pubkey_pem( const mbedtls_pk_context *key, unsigned char *buf, size_t size ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| 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( const mbedtls_pk_context *key, unsigned char *buf, size_t size ) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| 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 */ |
