Start parsing RSASSA-PSS parameters
diff --git a/library/x509.c b/library/x509.c
index 9915518..45dcea0 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -138,6 +138,92 @@
}
/*
+ * RSASSA-PSS-params ::= SEQUENCE {
+ * hashAlgorithm [0] HashAlgorithm DEFAULT sha1Identifier,
+ * maskGenAlgorithm [1] MaskGenAlgorithm DEFAULT mgf1SHA1Identifier,
+ * saltLength [2] INTEGER DEFAULT 20,
+ * trailerField [3] INTEGER DEFAULT 1 }
+ * -- Note that the tags in this Sequence are explicit.
+ */
+int x509_get_rsassa_pss_params( const x509_buf *params,
+ md_type_t *md_alg,
+ int *salt_len,
+ int *trailer_field )
+{
+ int ret;
+ unsigned char *p;
+ const unsigned char *end;
+ size_t len;
+ x509_buf alg_id;
+
+ /* First set everything to defaults */
+ *md_alg = POLARSSL_MD_SHA1;
+ *salt_len = 20;
+ *trailer_field = 1;
+
+ /* Make sure params is a SEQUENCE and setup bounds */
+ if( params->tag != ( ASN1_CONSTRUCTED | ASN1_SEQUENCE ) )
+ return( POLARSSL_ERR_X509_INVALID_ALG +
+ POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
+
+ p = (unsigned char *) params->p;
+ end = p + params->len;
+
+ if( p == end )
+ return( 0 );
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 0 ) ) == 0 )
+ {
+ /* HashAlgorithm ::= AlgorithmIdentifier (without parameters) */
+ // TODO: WIP
+ }
+ else if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ return( POLARSSL_ERR_X509_INVALID_ALG + ret );
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 1 ) ) == 0 )
+ {
+ /* MaskGenAlgorithm ::= AlgorithmIdentifier */
+ // TODO: WIP
+ }
+ else if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ return( POLARSSL_ERR_X509_INVALID_ALG + ret );
+
+ if( p == end )
+ return( 0 );
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 2 ) ) == 0 )
+ {
+ /* salt_len */
+ if( ( ret = asn1_get_int( &p, p + len, salt_len ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_ALG + ret );
+ }
+ else if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ return( POLARSSL_ERR_X509_INVALID_ALG + ret );
+
+ if( p == end )
+ return( 0 );
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 3 ) ) == 0 )
+ {
+ /* trailer_field */
+ if( ( ret = asn1_get_int( &p, p + len, trailer_field ) ) != 0 )
+ return( POLARSSL_ERR_X509_INVALID_ALG + ret );
+ }
+ else if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ return( POLARSSL_ERR_X509_INVALID_ALG + ret );
+
+ if( p != end )
+ return( POLARSSL_ERR_X509_INVALID_ALG +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ return( 0 );
+}
+
+/*
* AttributeTypeAndValue ::= SEQUENCE {
* type AttributeType,
* value AttributeValue }