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authorlloyd <[email protected]>2014-01-10 03:41:59 +0000
committerlloyd <[email protected]>2014-01-10 03:41:59 +0000
commit6894dca64c04936d07048c0e8cbf7e25858548c3 (patch)
tree5d572bfde9fe667dab14e3f04b5285a85d8acd95 /src/lib/pubkey/ecdsa/ecdsa.cpp
parent9efa3be92442afb3d0b69890a36c7f122df18eda (diff)
Move lib into src
Diffstat (limited to 'src/lib/pubkey/ecdsa/ecdsa.cpp')
-rw-r--r--src/lib/pubkey/ecdsa/ecdsa.cpp97
1 files changed, 97 insertions, 0 deletions
diff --git a/src/lib/pubkey/ecdsa/ecdsa.cpp b/src/lib/pubkey/ecdsa/ecdsa.cpp
new file mode 100644
index 000000000..6ff082649
--- /dev/null
+++ b/src/lib/pubkey/ecdsa/ecdsa.cpp
@@ -0,0 +1,97 @@
+/*
+* ECDSA implemenation
+* (C) 2007 Manuel Hartl, FlexSecure GmbH
+* 2007 Falko Strenzke, FlexSecure GmbH
+* 2008-2010 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/ecdsa.h>
+#include <botan/keypair.h>
+
+namespace Botan {
+
+bool ECDSA_PrivateKey::check_key(RandomNumberGenerator& rng,
+ bool strong) const
+ {
+ if(!public_point().on_the_curve())
+ return false;
+
+ if(!strong)
+ return true;
+
+ return KeyPair::signature_consistency_check(rng, *this, "EMSA1(SHA-1)");
+ }
+
+ECDSA_Signature_Operation::ECDSA_Signature_Operation(const ECDSA_PrivateKey& ecdsa) :
+ base_point(ecdsa.domain().get_base_point()),
+ order(ecdsa.domain().get_order()),
+ x(ecdsa.private_value()),
+ mod_order(order)
+ {
+ }
+
+secure_vector<byte>
+ECDSA_Signature_Operation::sign(const byte msg[], size_t msg_len,
+ RandomNumberGenerator& rng)
+ {
+ rng.add_entropy(msg, msg_len);
+
+ BigInt m(msg, msg_len);
+
+ BigInt r = 0, s = 0;
+
+ while(r == 0 || s == 0)
+ {
+ // This contortion is necessary for the tests
+ BigInt k;
+ k.randomize(rng, order.bits());
+
+ while(k >= order)
+ k.randomize(rng, order.bits() - 1);
+
+ PointGFp k_times_P = base_point * k;
+ r = mod_order.reduce(k_times_P.get_affine_x());
+ s = mod_order.multiply(inverse_mod(k, order), mul_add(x, r, m));
+ }
+
+ secure_vector<byte> output(2*order.bytes());
+ r.binary_encode(&output[output.size() / 2 - r.bytes()]);
+ s.binary_encode(&output[output.size() - s.bytes()]);
+ return output;
+ }
+
+ECDSA_Verification_Operation::ECDSA_Verification_Operation(const ECDSA_PublicKey& ecdsa) :
+ base_point(ecdsa.domain().get_base_point()),
+ public_point(ecdsa.public_point()),
+ order(ecdsa.domain().get_order())
+ {
+ }
+
+bool ECDSA_Verification_Operation::verify(const byte msg[], size_t msg_len,
+ const byte sig[], size_t sig_len)
+ {
+ if(sig_len != order.bytes()*2)
+ return false;
+
+ BigInt e(msg, msg_len);
+
+ BigInt r(sig, sig_len / 2);
+ BigInt s(sig + sig_len / 2, sig_len / 2);
+
+ if(r <= 0 || r >= order || s <= 0 || s >= order)
+ return false;
+
+ BigInt w = inverse_mod(s, order);
+
+ PointGFp R = w * multi_exponentiate(base_point, e,
+ public_point, r);
+
+ if(R.is_zero())
+ return false;
+
+ return (R.get_affine_x() % order == r);
+ }
+
+}