diff --git a/library/pem.c b/library/pem.c index 8dd86a4ac..5303adcc4 100644 --- a/library/pem.c +++ b/library/pem.c @@ -82,31 +82,33 @@ static int pem_get_iv( const unsigned char *s, unsigned char *iv, return( 0 ); } -static void pem_pbkdf1( unsigned char *key, size_t keylen, - unsigned char *iv, - const unsigned char *pwd, size_t pwdlen ) +static int pem_pbkdf1( unsigned char *key, size_t keylen, + unsigned char *iv, + const unsigned char *pwd, size_t pwdlen ) { mbedtls_md5_context md5_ctx; unsigned char md5sum[16]; size_t use_len; + int ret; mbedtls_md5_init( &md5_ctx ); /* * key[ 0..15] = MD5(pwd || IV) */ - mbedtls_md5_starts( &md5_ctx ); - mbedtls_md5_update( &md5_ctx, pwd, pwdlen ); - mbedtls_md5_update( &md5_ctx, iv, 8 ); - mbedtls_md5_finish( &md5_ctx, md5sum ); + if( ( ret = mbedtls_md5_starts_ext( &md5_ctx ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md5_update_ext( &md5_ctx, pwd, pwdlen ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md5_update_ext( &md5_ctx, iv, 8 ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md5_finish_ext( &md5_ctx, md5sum ) ) != 0 ) + goto exit; if( keylen <= 16 ) { memcpy( key, md5sum, keylen ); - - mbedtls_md5_free( &md5_ctx ); - mbedtls_zeroize( md5sum, 16 ); - return; + goto exit; } memcpy( key, md5sum, 16 ); @@ -114,11 +116,16 @@ static void pem_pbkdf1( unsigned char *key, size_t keylen, /* * key[16..23] = MD5(key[ 0..15] || pwd || IV]) */ - mbedtls_md5_starts( &md5_ctx ); - mbedtls_md5_update( &md5_ctx, md5sum, 16 ); - mbedtls_md5_update( &md5_ctx, pwd, pwdlen ); - mbedtls_md5_update( &md5_ctx, iv, 8 ); - mbedtls_md5_finish( &md5_ctx, md5sum ); + if( ( ret = mbedtls_md5_starts_ext( &md5_ctx ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md5_update_ext( &md5_ctx, md5sum, 16 ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md5_update_ext( &md5_ctx, pwd, pwdlen ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md5_update_ext( &md5_ctx, iv, 8 ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md5_finish_ext( &md5_ctx, md5sum ) ) != 0 ) + goto exit; use_len = 16; if( keylen < 32 ) @@ -126,53 +133,66 @@ static void pem_pbkdf1( unsigned char *key, size_t keylen, memcpy( key + 16, md5sum, use_len ); +exit: mbedtls_md5_free( &md5_ctx ); mbedtls_zeroize( md5sum, 16 ); + + return( ret ); } #if defined(MBEDTLS_DES_C) /* * Decrypt with DES-CBC, using PBKDF1 for key derivation */ -static void pem_des_decrypt( unsigned char des_iv[8], - unsigned char *buf, size_t buflen, - const unsigned char *pwd, size_t pwdlen ) +static int pem_des_decrypt( unsigned char des_iv[8], + unsigned char *buf, size_t buflen, + const unsigned char *pwd, size_t pwdlen ) { mbedtls_des_context des_ctx; unsigned char des_key[8]; + int ret; mbedtls_des_init( &des_ctx ); - pem_pbkdf1( des_key, 8, des_iv, pwd, pwdlen ); + if( ( ret = pem_pbkdf1( des_key, 8, des_iv, pwd, pwdlen ) ) != 0 ) + goto exit; mbedtls_des_setkey_dec( &des_ctx, des_key ); mbedtls_des_crypt_cbc( &des_ctx, MBEDTLS_DES_DECRYPT, buflen, des_iv, buf, buf ); +exit: mbedtls_des_free( &des_ctx ); mbedtls_zeroize( des_key, 8 ); + + return( ret ); } /* * Decrypt with 3DES-CBC, using PBKDF1 for key derivation */ -static void pem_des3_decrypt( unsigned char des3_iv[8], - unsigned char *buf, size_t buflen, - const unsigned char *pwd, size_t pwdlen ) +static int pem_des3_decrypt( unsigned char des3_iv[8], + unsigned char *buf, size_t buflen, + const unsigned char *pwd, size_t pwdlen ) { mbedtls_des3_context des3_ctx; unsigned char des3_key[24]; + int ret; mbedtls_des3_init( &des3_ctx ); - pem_pbkdf1( des3_key, 24, des3_iv, pwd, pwdlen ); + if( ( ret = pem_pbkdf1( des3_key, 24, des3_iv, pwd, pwdlen ) ) != 0 ) + goto exit; mbedtls_des3_set3key_dec( &des3_ctx, des3_key ); mbedtls_des3_crypt_cbc( &des3_ctx, MBEDTLS_DES_DECRYPT, buflen, des3_iv, buf, buf ); +exit: mbedtls_des3_free( &des3_ctx ); mbedtls_zeroize( des3_key, 24 ); + + return( ret ); } #endif /* MBEDTLS_DES_C */ @@ -180,23 +200,28 @@ static void pem_des3_decrypt( unsigned char des3_iv[8], /* * Decrypt with AES-XXX-CBC, using PBKDF1 for key derivation */ -static void pem_aes_decrypt( unsigned char aes_iv[16], unsigned int keylen, - unsigned char *buf, size_t buflen, - const unsigned char *pwd, size_t pwdlen ) +static int pem_aes_decrypt( unsigned char aes_iv[16], unsigned int keylen, + unsigned char *buf, size_t buflen, + const unsigned char *pwd, size_t pwdlen ) { mbedtls_aes_context aes_ctx; unsigned char aes_key[32]; + int ret; mbedtls_aes_init( &aes_ctx ); - pem_pbkdf1( aes_key, keylen, aes_iv, pwd, pwdlen ); + if( ( ret = pem_pbkdf1( aes_key, keylen, aes_iv, pwd, pwdlen ) ) != 0 ) + goto exit; mbedtls_aes_setkey_dec( &aes_ctx, aes_key, keylen * 8 ); mbedtls_aes_crypt_cbc( &aes_ctx, MBEDTLS_AES_DECRYPT, buflen, aes_iv, buf, buf ); +exit: mbedtls_aes_free( &aes_ctx ); mbedtls_zeroize( aes_key, keylen ); + + return( ret ); } #endif /* MBEDTLS_AES_C */ @@ -345,22 +370,30 @@ int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const return( MBEDTLS_ERR_PEM_PASSWORD_REQUIRED ); } + ret = 0; + #if defined(MBEDTLS_DES_C) if( enc_alg == MBEDTLS_CIPHER_DES_EDE3_CBC ) - pem_des3_decrypt( pem_iv, buf, len, pwd, pwdlen ); + ret = pem_des3_decrypt( pem_iv, buf, len, pwd, pwdlen ); else if( enc_alg == MBEDTLS_CIPHER_DES_CBC ) - pem_des_decrypt( pem_iv, buf, len, pwd, pwdlen ); + ret = pem_des_decrypt( pem_iv, buf, len, pwd, pwdlen ); #endif /* MBEDTLS_DES_C */ #if defined(MBEDTLS_AES_C) if( enc_alg == MBEDTLS_CIPHER_AES_128_CBC ) - pem_aes_decrypt( pem_iv, 16, buf, len, pwd, pwdlen ); + ret = pem_aes_decrypt( pem_iv, 16, buf, len, pwd, pwdlen ); else if( enc_alg == MBEDTLS_CIPHER_AES_192_CBC ) - pem_aes_decrypt( pem_iv, 24, buf, len, pwd, pwdlen ); + ret = pem_aes_decrypt( pem_iv, 24, buf, len, pwd, pwdlen ); else if( enc_alg == MBEDTLS_CIPHER_AES_256_CBC ) - pem_aes_decrypt( pem_iv, 32, buf, len, pwd, pwdlen ); + ret = pem_aes_decrypt( pem_iv, 32, buf, len, pwd, pwdlen ); #endif /* MBEDTLS_AES_C */ + if( ret != 0 ) + { + mbedtls_free( buf ); + return( ret ); + } + /* * The result will be ASN.1 starting with a SEQUENCE tag, with 1 to 3 * length bytes (allow 4 to be sure) in all known use cases.