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authorVadim Dashevskiy <watcherhd@gmail.com>2012-05-15 10:38:20 +0000
committerVadim Dashevskiy <watcherhd@gmail.com>2012-05-15 10:38:20 +0000
commit48540940b6c28bb4378abfeb500ec45a625b37b6 (patch)
tree2ef294c0763e802f91d868bdef4229b6868527de /plugins/CryptoPP/crypto/emsa2.cpp
parent5c350913f011e119127baeb32a6aedeb4f0d33bc (diff)
initial commit
git-svn-id: http://svn.miranda-ng.org/main/trunk@2 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
Diffstat (limited to 'plugins/CryptoPP/crypto/emsa2.cpp')
-rw-r--r--plugins/CryptoPP/crypto/emsa2.cpp34
1 files changed, 34 insertions, 0 deletions
diff --git a/plugins/CryptoPP/crypto/emsa2.cpp b/plugins/CryptoPP/crypto/emsa2.cpp
new file mode 100644
index 0000000000..43974358f6
--- /dev/null
+++ b/plugins/CryptoPP/crypto/emsa2.cpp
@@ -0,0 +1,34 @@
+// emsa2.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+#include "emsa2.h"
+
+#ifndef CRYPTOPP_IMPORTS
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void EMSA2Pad::ComputeMessageRepresentative(RandomNumberGenerator &rng,
+ const byte *recoverableMessage, size_t recoverableMessageLength,
+ HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
+ byte *representative, size_t representativeBitLength) const
+{
+ assert(representativeBitLength >= MinRepresentativeBitLength(hashIdentifier.second, hash.DigestSize()));
+
+ if (representativeBitLength % 8 != 7)
+ throw PK_SignatureScheme::InvalidKeyLength("EMSA2: EMSA2 requires a key length that is a multiple of 8");
+
+ size_t digestSize = hash.DigestSize();
+ size_t representativeByteLength = BitsToBytes(representativeBitLength);
+
+ representative[0] = messageEmpty ? 0x4b : 0x6b;
+ memset(representative+1, 0xbb, representativeByteLength-digestSize-4); // pad with 0xbb
+ byte *afterP2 = representative+representativeByteLength-digestSize-3;
+ afterP2[0] = 0xba;
+ hash.Final(afterP2+1);
+ representative[representativeByteLength-2] = *hashIdentifier.first;
+ representative[representativeByteLength-1] = 0xcc;
+}
+
+NAMESPACE_END
+
+#endif