/** * \file pkcs5.c * * \brief PKCS#5 functions * * \author Mathias Olsson * * 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) */ /* * PKCS#5 includes PBKDF2 and more * * http://tools.ietf.org/html/rfc2898 (Specification) * http://tools.ietf.org/html/rfc6070 (Test vectors) */ #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #if defined(MBEDTLS_PKCS5_C) #include "mbedtls/pkcs5.h" #include "mbedtls/asn1.h" #include "mbedtls/cipher.h" #include "mbedtls/oid.h" #include #include static int pkcs5_parse_pbkdf2_params( const mbedtls_asn1_buf *params, mbedtls_asn1_buf *salt, int *iterations, int *keylen, mbedtls_md_type_t *md_type ) { int ret; mbedtls_asn1_buf prf_alg_oid; unsigned char *p = params->p; const unsigned char *end = params->p + params->len; if( params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ); /* * PBKDF2-params ::= SEQUENCE { * salt OCTET STRING, * iterationCount INTEGER, * keyLength INTEGER OPTIONAL * prf AlgorithmIdentifier DEFAULT algid-hmacWithSHA1 * } * */ if( ( ret = mbedtls_asn1_get_tag( &p, end, &salt->len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ) return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret ); salt->p = p; p += salt->len; if( ( ret = mbedtls_asn1_get_int( &p, end, iterations ) ) != 0 ) return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret ); if( p == end ) return( 0 ); if( ( ret = mbedtls_asn1_get_int( &p, end, keylen ) ) != 0 ) { if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret ); } if( p == end ) return( 0 ); if( ( ret = mbedtls_asn1_get_alg_null( &p, end, &prf_alg_oid ) ) != 0 ) return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret ); if( MBEDTLS_OID_CMP( MBEDTLS_OID_HMAC_SHA1, &prf_alg_oid ) != 0 ) return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE ); *md_type = MBEDTLS_MD_SHA1; if( p != end ) return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + MBEDTLS_ERR_ASN1_LENGTH_MISMATCH ); return( 0 ); } int mbedtls_pkcs5_pbes2( const mbedtls_asn1_buf *pbe_params, int mode, const unsigned char *pwd, size_t pwdlen, const unsigned char *data, size_t datalen, unsigned char *output ) { int ret, iterations = 0, keylen = 0; unsigned char *p, *end; mbedtls_asn1_buf kdf_alg_oid, enc_scheme_oid, kdf_alg_params, enc_scheme_params; mbedtls_asn1_buf salt; mbedtls_md_type_t md_type = MBEDTLS_MD_SHA1; unsigned char key[32], iv[32]; size_t olen = 0; const mbedtls_md_info_t *md_info; const mbedtls_cipher_info_t *cipher_info; mbedtls_md_context_t md_ctx; mbedtls_cipher_type_t cipher_alg; mbedtls_cipher_context_t cipher_ctx; p = pbe_params->p; end = p + pbe_params->len; /* * PBES2-params ::= SEQUENCE { * keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}}, * encryptionScheme AlgorithmIdentifier {{PBES2-Encs}} * } */ if( pbe_params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ); if( ( ret = mbedtls_asn1_get_alg( &p, end, &kdf_alg_oid, &kdf_alg_params ) ) != 0 ) return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret ); /* Only PBKDF2 supported at the moment */ if( MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS5_PBKDF2, &kdf_alg_oid ) != 0 ) return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE ); if( ( ret = pkcs5_parse_pbkdf2_params( &kdf_alg_params, &salt, &iterations, &keylen, &md_type ) ) != 0 ) { return( ret ); } md_info = mbedtls_md_info_from_type( md_type ); if( md_info == NULL ) return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE ); if( ( ret = mbedtls_asn1_get_alg( &p, end, &enc_scheme_oid, &enc_scheme_params ) ) != 0 ) { return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret ); } if( mbedtls_oid_get_cipher_alg( &enc_scheme_oid, &cipher_alg ) != 0 ) return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE ); cipher_info = mbedtls_cipher_info_from_type( cipher_alg ); if( cipher_info == NULL ) return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE ); /* * The value of keylen from pkcs5_parse_pbkdf2_params() is ignored * since it is optional and we don't know if it was set or not */ keylen = cipher_info->key_bitlen / 8; if( enc_scheme_params.tag != MBEDTLS_ASN1_OCTET_STRING || enc_scheme_params.len != cipher_info->iv_size ) { return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT ); } mbedtls_md_init( &md_ctx ); mbedtls_cipher_init( &cipher_ctx ); memcpy( iv, enc_scheme_params.p, enc_scheme_params.len ); if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 1 ) ) != 0 ) goto exit; if( ( ret = mbedtls_pkcs5_pbkdf2_hmac( &md_ctx, pwd, pwdlen, salt.p, salt.len, iterations, keylen, key ) ) != 0 ) { goto exit; } if( ( ret = mbedtls_cipher_setup( &cipher_ctx, cipher_info ) ) != 0 ) goto exit; if( ( ret = mbedtls_cipher_setkey( &cipher_ctx, key, 8 * keylen, (mbedtls_operation_t) mode ) ) != 0 ) goto exit; if( ( ret = mbedtls_cipher_crypt( &cipher_ctx, iv, enc_scheme_params.len, data, datalen, output, &olen ) ) != 0 ) ret = MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH; exit: mbedtls_md_free( &md_ctx ); mbedtls_cipher_free( &cipher_ctx ); return( ret ); } int mbedtls_pkcs5_pbkdf2_hmac( mbedtls_md_context_t *ctx, const unsigned char *password, size_t plen, const unsigned char *salt, size_t slen, unsigned int iteration_count, uint32_t key_length, unsigned char *output ) { int ret, j; unsigned int i; unsigned char md1[MBEDTLS_MD_MAX_SIZE]; unsigned char work[MBEDTLS_MD_MAX_SIZE]; unsigned char md_size = mbedtls_md_get_size( ctx->md_info ); size_t use_len; unsigned char *out_p = output; unsigned char counter[4]; memset( counter, 0, 4 ); counter[3] = 1; if( iteration_count > 0xFFFFFFFF ) return( MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA ); while( key_length ) { /* U1 ends up in work */ if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 ) return( ret ); if( ( ret = mbedtls_md_hmac_update( ctx, salt, slen ) ) != 0 ) return( ret ); if( ( ret = mbedtls_md_hmac_update( ctx, counter, 4 ) ) != 0 ) return( ret ); if( ( ret = mbedtls_md_hmac_finish( ctx, work ) ) != 0 ) return( ret ); memcpy( md1, work, md_size ); for( i = 1; i < iteration_count; i++ ) { /* U2 ends up in md1 */ if( ( ret = mbedtls_md_hmac_starts( ctx, password, plen ) ) != 0 ) return( ret ); if( ( ret = mbedtls_md_hmac_update( ctx, md1, md_size ) ) != 0 ) return( ret ); if( ( ret = mbedtls_md_hmac_finish( ctx, md1 ) ) != 0 ) return( ret ); /* U1 xor U2 */ for( j = 0; j < md_size; j++ ) work[j] ^= md1[j]; } use_len = ( key_length < md_size ) ? key_length : md_size; memcpy( out_p, work, use_len ); key_length -= (uint32_t) use_len; out_p += use_len; for( i = 4; i > 0; i-- ) if( ++counter[i - 1] != 0 ) break; } return( 0 ); } #endif /* MBEDTLS_PKCS5_C */