int mbedtls_ecies_read_hmac(unsigned char **p, const unsigned char *end,
mbedtls_md_type_t *hmac_type, unsigned char **hmac, size_t *hmac_len)
{
int result = 0;
size_t len = 0;
mbedtls_asn1_buf hmac_alg;
if (hmac_type == NULL || hmac == NULL)
{
return MBEDTLS_ERR_ECIES_BAD_INPUT_DATA;
}
INVOKE_AND_CHECK(result,
mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)
);
INVOKE_AND_CHECK(result,
mbedtls_asn1_get_alg_null(p, end, &hmac_alg)
);
INVOKE_AND_CHECK(result,
mbedtls_oid_get_md_alg(&hmac_alg, hmac_type)
);
INVOKE_AND_CHECK(result,
mbedtls_asn1_get_tag(p, end, hmac_len, MBEDTLS_ASN1_OCTET_STRING)
);
*hmac = *p;
*p += *hmac_len;
return result;
}
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 );
}
/* Get an algorithm identifier without parameters (eg for signatures)
*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL }
*/
int mbedtls_x509_get_alg_null( unsigned char **p, const unsigned char *end,
mbedtls_x509_buf *alg )
{
int ret;
if( ( ret = mbedtls_asn1_get_alg_null( p, end, alg ) ) != 0 )
return( MBEDTLS_ERR_X509_INVALID_ALG + ret );
return( 0 );
}
