Add support for full signature verification

[onak.git] / rsa.c

diff --git a/rsa.c b/rsa.c
new file mode 100644 (file)
index 0000000..ceb81e1
--- /dev/null
+++ b/rsa.c
@@ -0,0 +1,79 @@
+/*
+ * rsa.c - routines to check RSA hash signature combos not present in libnettle
+ *
+ * Copyright 2019 Jonathan McDowell <noodles@earth.li>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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 <https://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+
+#include <nettle/ripemd160.h>
+#include <nettle/rsa.h>
+#include <nettle/sha.h>
+
+#include "rsa.h"
+
+const uint8_t ripemd160_prefix[] = { 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
+       0x2B, 0x24, 0x03, 0x02, 0x01,
+       0x05, 0x00,
+       0x04, 0x14
+};
+
+const uint8_t sha224_prefix[] = { 0x30, 0x2D, 0x30, 0x0d, 0x06, 0x09,
+       0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
+       0x05, 0x00,
+       0x04, 0x1c
+};
+
+const uint8_t sha384_prefix[] = { 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
+       0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
+       0x05, 0x00,
+       0x04, 0x3
+};
+
+int rsa_ripemd160_verify_digest(const struct rsa_public_key *key,
+                        const uint8_t *digest,
+                        const mpz_t s)
+{
+       uint8_t buf[sizeof(ripemd160_prefix) + RIPEMD160_DIGEST_SIZE];
+
+       memcpy(buf, ripemd160_prefix, sizeof(ripemd160_prefix));
+       memcpy(buf + sizeof(ripemd160_prefix), digest, RIPEMD160_DIGEST_SIZE);
+
+       return rsa_pkcs1_verify(key, sizeof(buf), buf, s);
+}
+
+int rsa_sha224_verify_digest(const struct rsa_public_key *key,
+                        const uint8_t *digest,
+                        const mpz_t s)
+{
+       uint8_t buf[sizeof(sha224_prefix) + SHA224_DIGEST_SIZE];
+
+       memcpy(buf, sha224_prefix, sizeof(sha224_prefix));
+       memcpy(buf + sizeof(sha224_prefix), digest, SHA224_DIGEST_SIZE);
+
+       return rsa_pkcs1_verify(key, sizeof(buf), buf, s);
+}
+
+int rsa_sha384_verify_digest(const struct rsa_public_key *key,
+                        const uint8_t *digest,
+                        const mpz_t s)
+{
+       uint8_t buf[sizeof(sha384_prefix) + SHA384_DIGEST_SIZE];
+
+       memcpy(buf, sha384_prefix, sizeof(sha384_prefix));
+       memcpy(buf + sizeof(sha384_prefix), digest, SHA384_DIGEST_SIZE);
+
+       return rsa_pkcs1_verify(key, sizeof(buf), buf, s);
+}