New "i15" implementation of big integers (faster, and constant-time, on ARM Cortex...

[BearSSL] / src / ec / ecdsa_i15_sign_asn1.c

diff --git a/src/ec/ecdsa_i15_sign_asn1.c b/src/ec/ecdsa_i15_sign_asn1.c
new file mode 100644 (file)
index 0000000..ab4a283
--- /dev/null
+++ b/src/ec/ecdsa_i15_sign_asn1.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+#define ORDER_LEN   ((BR_MAX_EC_SIZE + 7) >> 3)
+
+/* see bearssl_ec.h */
+size_t
+br_ecdsa_i15_sign_asn1(const br_ec_impl *impl,
+       const br_hash_class *hf, const void *hash_value,
+       const br_ec_private_key *sk, void *sig)
+{
+       unsigned char rsig[(ORDER_LEN << 1) + 12];
+       size_t sig_len;
+
+       sig_len = br_ecdsa_i15_sign_raw(impl, hf, hash_value, sk, rsig);
+       if (sig_len == 0) {
+               return 0;
+       }
+       sig_len = br_ecdsa_raw_to_asn1(rsig, sig_len);
+       memcpy(sig, rsig, sig_len);
+       return sig_len;
+}