1 files changed, 109 insertions, 0 deletions
diff --git a/src/utils/common/sign.c b/src/utils/common/sign.c
new file mode 100644
index 0000000..f8e9f29
--- /dev/null
+++ b/src/utils/common/sign.c
@@ -0,0 +1,109 @@
+/*  Copyright (C) 2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <string.h>
+
+#include "utils/common/sign.h"
+#include "libknot/errcode.h"
+#include "libknot/tsig-op.h"
+
+int sign_context_init_tsig(sign_context_t *ctx, const knot_tsig_key_t *key)
+{
+	if (!ctx || !key) {
+		return KNOT_EINVAL;
+	}
+
+	size_t digest_size = dnssec_tsig_algorithm_size(key->algorithm);
+	if (digest_size == 0) {
+		return KNOT_EINVAL;
+	}
+
+	uint8_t *digest = calloc(1, digest_size);
+	if (!digest) {
+		return KNOT_ENOMEM;
+	}
+
+	ctx->digest_size = digest_size;
+	ctx->digest = digest;
+	ctx->tsig_key = key;
+
+	return KNOT_EOK;
+}
+
+void sign_context_deinit(sign_context_t *ctx)
+{
+	if (!ctx) {
+		return;
+	}
+
+	free(ctx->digest);
+
+	memset(ctx, 0, sizeof(*ctx));
+}
+
+int sign_packet(knot_pkt_t *pkt, sign_context_t *sign_ctx)
+{
+	if (pkt == NULL || sign_ctx == NULL || sign_ctx->digest == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	uint8_t *wire = pkt->wire;
+	size_t  *wire_size = &pkt->size;
+	size_t  max_size = pkt->max_size;
+
+	int ret = knot_pkt_reserve(pkt, knot_tsig_wire_size(sign_ctx->tsig_key));
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	return knot_tsig_sign(wire, wire_size, max_size, NULL, 0,
+	                      sign_ctx->digest, &sign_ctx->digest_size,
+	                      sign_ctx->tsig_key, 0, 0);
+}
+
+int verify_packet(const knot_pkt_t *pkt, const sign_context_t *sign_ctx)
+{
+	if (pkt == NULL || sign_ctx == NULL || sign_ctx->digest == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	const uint8_t *wire = pkt->wire;
+	const size_t  *wire_size = &pkt->size;
+
+	if (pkt->tsig_rr == NULL) {
+		return KNOT_ENOTSIG;
+	}
+
+	int ret = knot_tsig_client_check(pkt->tsig_rr, wire, *wire_size,
+	                                 sign_ctx->digest, sign_ctx->digest_size,
+	                                 sign_ctx->tsig_key, 0);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	switch (knot_tsig_rdata_error(pkt->tsig_rr)) {
+	case KNOT_RCODE_BADSIG:
+		return KNOT_TSIG_EBADSIG;
+	case KNOT_RCODE_BADKEY:
+		return KNOT_TSIG_EBADKEY;
+	case KNOT_RCODE_BADTIME:
+		return KNOT_TSIG_EBADTIME;
+	case KNOT_RCODE_BADTRUNC:
+		return KNOT_TSIG_EBADTRUNC;
+	default:
+		return KNOT_EOK;
+	}
+}