Added function for DS algorithm length calculation.

- Copied from descriptor.c

src/common/descriptor.c

@@ -36,6 +36,15 @@ static knot_lookup_table_t dns_classes[] = {
 	{ 0, NULL }
 };
 
+/*! \brief DS digest lengths. */
+enum knot_ds_algorithm_len
+{
+	KNOT_DS_DIGEST_LEN_SHA1 = 20,	/* 20B - RFC 3658 */
+	KNOT_DS_DIGEST_LEN_SHA256 = 32,	/* 32B - RFC 4509 */
+	KNOT_DS_DIGEST_LEN_GOST = 32,	/* 32B - RFC 5933 */
+	KNOT_DS_DIGEST_LEN_SHA384 = 48	/* 48B - RFC 6605 */
+};
+
 /*!
  * \brief RR type descriptors.
  */
@@ -282,3 +291,20 @@ int knot_rrtype_is_metatype(const uint16_t type)
 	        type == KNOT_RRTYPE_ANY);
 }
 
+
+size_t knot_ds_digest_length(uint8_t algorithm)
+{
+	switch (algorithm) {
+		case KNOT_DS_ALG_SHA1:
+			return KNOT_DS_DIGEST_LEN_SHA1;
+		case KNOT_DS_ALG_SHA256:
+			return KNOT_DS_DIGEST_LEN_SHA256;
+		case KNOT_DS_ALG_GOST:
+			return KNOT_DS_DIGEST_LEN_GOST;
+		case KNOT_DS_ALG_SHA384:
+			return KNOT_DS_DIGEST_LEN_SHA384;
+		default:
+			return 0;
+	}
+}
+

src/common/descriptor.h

@@ -115,6 +115,38 @@ enum knot_rdata_wireformat {
 	KNOT_RDATA_WF_END                =   0,
 };
 
+/*! \brief Constants for DNSSEC algorithm types.
+ *
+ * Source: http://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xml
+ */
+enum knot_dnssec_algorithm
+{
+	KNOT_DNSSEC_ALG_RSAMD5 = 1,
+	KNOT_DNSSEC_ALG_DH = 2,
+	KNOT_DNSSEC_ALG_DSA = 3,
+	KNOT_DNSSEC_ALG_RSASHA1 = 5,
+	KNOT_DNSSEC_ALG_DSA_NSEC3_SHA1 = 6,
+	KNOT_DNSSEC_ALG_RSASHA1_NSEC3_SHA1 = 7,
+	KNOT_DNSSEC_ALG_RSASHA256 = 8,
+	KNOT_DNSSEC_ALG_RSASHA512 = 10,
+	KNOT_DNSSEC_ALG_ECC_GOST = 12,
+	KNOT_DNSSEC_ALG_ECDSAP256SHA256 = 13,
+	KNOT_DNSSEC_ALG_ECDSAP384SHA384 = 14
+};
+
+/*! \brief Constants for DNSSEC algorithm types.
+ *
+ * Source: http://www.iana.org/assignments/ds-rr-types/ds-rr-types.xml
+ */
+enum knot_ds_algorithm
+{
+	KNOT_DS_ALG_SHA1 = 1,	/* 20B - RFC 3658 */
+	KNOT_DS_ALG_SHA256 = 2,	/* 32B - RFC 4509 */
+	KNOT_DS_ALG_GOST = 3,	/* 32B - RFC 5933 */
+	KNOT_DS_ALG_SHA384 = 4	/* 48B - RFC 6605 */
+};
+
+
 /*!
  * \brief Structure describing rdata.
  */
@@ -235,6 +267,14 @@ int descriptor_item_is_remainder(const int item);
  */
 int knot_rrtype_is_metatype(const uint16_t type);
 
+/*!
+ * \brief Return length of DS digest for given algorithm.
+ *
+ * \param algorithm Algorithm code to be used
+ *
+ * \retval Digest length for given algorithm. 
+ */
+size_t knot_ds_digest_length(uint8_t algorithm);
 #endif // _KNOT_DESCRIPTOR_NEW_H_
 
 /*! @} */