Adding src/libsecp256k1/ecdsa.cpp

CMakeLists.txt

@@ -66,7 +66,11 @@ if (${EC_LIB} STREQUAL "libsecp256k1")
 	# Note: this is a big hack to get cmake to not export this library.
 	# Must be a better way, but works so cba.
 	LIST(APPEND LIB_PRIVATE_INCLUDE $<BUILD_INTERFACE:$<TARGET_PROPERTY:secp256k1,INCLUDE_DIRECTORIES>>)
-	LIST(APPEND LIB_SOURCE src/libsecp256k1/ec.cpp $<TARGET_OBJECTS:secp256k1>)
+	LIST(APPEND LIB_SOURCE
+		$<TARGET_OBJECTS:secp256k1>
+		src/libsecp256k1/ec.cpp
+		src/libsecp256k1/ecdsa.cpp
+	)
 
 elseif (${EC_LIB} STREQUAL "openssl")
 	LIST(APPEND LIB_SOURCE

src/libsecp256k1/ecdsa.cpp

@@ -0,0 +1,93 @@
+/**
+ * MIT License
+ *
+ * Copyright (c) 2019-2021 EOS Sw/eden
+ *
+ * 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 <secp256k1.h>
+#include <secp256k1_recovery.h>
+#include <libeosio/ec.hpp>
+#include "rng.h"
+
+namespace libeosio {
+
+extern secp256k1_context* ctx;
+
+int is_canonical(const unsigned char *d) {
+	return !(d[1] & 0x80)
+		&& !(d[1] == 0 && !(d[2] & 0x80))
+		&& !(d[33] & 0x80)
+		&& !(d[33] == 0 && !(d[34] & 0x80));
+}
+
+static int extended_nonce_function( unsigned char *nonce32, const unsigned char *msg32,
+                                        const unsigned char *key32, const unsigned char* algo16,
+                                        void* data, unsigned int attempt ) {
+	return secp256k1_nonce_function_rfc6979(nonce32, msg32, key32, algo16, nullptr, *(unsigned int*) data);
+}
+
+int ecdsa_sign(const ec_privkey_t& key, const sha256_t* digest, ec_signature_t& sig) {
+
+	for (unsigned int counter = 1; counter < 25; counter++) {
+
+		int v = 0;
+		secp256k1_ecdsa_recoverable_signature s;
+
+		if (!secp256k1_ecdsa_sign_recoverable(ctx, &s, digest->data, key.data(), extended_nonce_function, &counter)) {
+			return -1;
+		}
+
+		secp256k1_ecdsa_recoverable_signature_serialize_compact(ctx, sig.data() + 1, &v, &s);
+
+		if (is_canonical(sig.data())) {
+			sig[0] = 27 + 4 + v;
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+int ecdsa_verify(const sha256_t* digest, const ec_signature_t& sig, const ec_pubkey_t& key) {
+
+	secp256k1_ecdsa_signature ec_sig;
+	secp256k1_ecdsa_recoverable_signature ec_rec_sig;
+	secp256k1_pubkey pubkey;
+	int recid;
+
+	recid = sig.at(0) - 27 - 4;
+
+	// Parse signature
+	if (!secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &ec_rec_sig, sig.data() + 1, recid)) {
+		return -1;
+	}
+
+	// Parse public key
+	if (!secp256k1_ec_pubkey_parse(ctx, &pubkey, key.data(), key.size())) {
+		return -1;
+	}
+
+	// Verify
+	secp256k1_ecdsa_recoverable_signature_convert(ctx, &ec_sig, &ec_rec_sig);
+	return secp256k1_ecdsa_verify(ctx, &ec_sig, digest->data, &pubkey) > 0 ? 0 : -1;
+}
+
+
+} // namespace libeosio