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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/dh/dh.cpp
parent9efa3be92442afb3d0b69890a36c7f122df18eda (diff)
Move lib into src
Diffstat (limited to 'src/lib/pubkey/dh/dh.cpp')
-rw-r--r--src/lib/pubkey/dh/dh.cpp98
1 files changed, 98 insertions, 0 deletions
diff --git a/src/lib/pubkey/dh/dh.cpp b/src/lib/pubkey/dh/dh.cpp
new file mode 100644
index 000000000..55d53518a
--- /dev/null
+++ b/src/lib/pubkey/dh/dh.cpp
@@ -0,0 +1,98 @@
+/*
+* Diffie-Hellman
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/dh.h>
+#include <botan/numthry.h>
+#include <botan/workfactor.h>
+
+namespace Botan {
+
+/*
+* DH_PublicKey Constructor
+*/
+DH_PublicKey::DH_PublicKey(const DL_Group& grp, const BigInt& y1)
+ {
+ group = grp;
+ y = y1;
+ }
+
+/*
+* Return the public value for key agreement
+*/
+std::vector<byte> DH_PublicKey::public_value() const
+ {
+ return unlock(BigInt::encode_1363(y, group_p().bytes()));
+ }
+
+/*
+* Create a DH private key
+*/
+DH_PrivateKey::DH_PrivateKey(RandomNumberGenerator& rng,
+ const DL_Group& grp,
+ const BigInt& x_arg)
+ {
+ group = grp;
+ x = x_arg;
+
+ if(x == 0)
+ {
+ const BigInt& p = group_p();
+ x.randomize(rng, 2 * dl_work_factor(p.bits()));
+ }
+
+ if(y == 0)
+ y = power_mod(group_g(), x, group_p());
+
+ if(x == 0)
+ gen_check(rng);
+ else
+ load_check(rng);
+ }
+
+/*
+* Load a DH private key
+*/
+DH_PrivateKey::DH_PrivateKey(const AlgorithmIdentifier& alg_id,
+ const secure_vector<byte>& key_bits,
+ RandomNumberGenerator& rng) :
+ DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_42)
+ {
+ if(y == 0)
+ y = power_mod(group_g(), x, group_p());
+
+ load_check(rng);
+ }
+
+/*
+* Return the public value for key agreement
+*/
+std::vector<byte> DH_PrivateKey::public_value() const
+ {
+ return DH_PublicKey::public_value();
+ }
+
+DH_KA_Operation::DH_KA_Operation(const DH_PrivateKey& dh,
+ RandomNumberGenerator& rng) :
+ p(dh.group_p()), powermod_x_p(dh.get_x(), p)
+ {
+ BigInt k(rng, p.bits() - 1);
+ blinder = Blinder(k, powermod_x_p(inverse_mod(k, p)), p);
+ }
+
+secure_vector<byte> DH_KA_Operation::agree(const byte w[], size_t w_len)
+ {
+ BigInt input = BigInt::decode(w, w_len);
+
+ if(input <= 1 || input >= p - 1)
+ throw Invalid_Argument("DH agreement - invalid key provided");
+
+ BigInt r = blinder.unblind(powermod_x_p(blinder.blind(input)));
+
+ return BigInt::encode_1363(r, p.bytes());
+ }
+
+}