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-rw-r--r--embeddedcryptopp/hmac.cpp86
1 files changed, 86 insertions, 0 deletions
diff --git a/embeddedcryptopp/hmac.cpp b/embeddedcryptopp/hmac.cpp
new file mode 100644
index 0000000..d4a649c
--- /dev/null
+++ b/embeddedcryptopp/hmac.cpp
@@ -0,0 +1,86 @@
+// hmac.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+
+#ifndef CRYPTOPP_IMPORTS
+
+#include "hmac.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void HMAC_Base::UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &)
+{
+ AssertValidKeyLength(keylength);
+
+ Restart();
+
+ HashTransformation &hash = AccessHash();
+ unsigned int blockSize = hash.BlockSize();
+
+ if (!blockSize)
+ throw InvalidArgument("HMAC: can only be used with a block-based hash function");
+
+ m_buf.resize(2*AccessHash().BlockSize() + AccessHash().DigestSize());
+
+ if (keylength <= blockSize)
+ memcpy(AccessIpad(), userKey, keylength);
+ else
+ {
+ AccessHash().CalculateDigest(AccessIpad(), userKey, keylength);
+ keylength = hash.DigestSize();
+ }
+
+ assert(keylength <= blockSize);
+ memset(AccessIpad()+keylength, 0, blockSize-keylength);
+
+ for (unsigned int i=0; i<blockSize; i++)
+ {
+ AccessOpad()[i] = AccessIpad()[i] ^ 0x5c;
+ AccessIpad()[i] ^= 0x36;
+ }
+}
+
+void HMAC_Base::KeyInnerHash()
+{
+ assert(!m_innerHashKeyed);
+ HashTransformation &hash = AccessHash();
+ hash.Update(AccessIpad(), hash.BlockSize());
+ m_innerHashKeyed = true;
+}
+
+void HMAC_Base::Restart()
+{
+ if (m_innerHashKeyed)
+ {
+ AccessHash().Restart();
+ m_innerHashKeyed = false;
+ }
+}
+
+void HMAC_Base::Update(const byte *input, size_t length)
+{
+ if (!m_innerHashKeyed)
+ KeyInnerHash();
+ AccessHash().Update(input, length);
+}
+
+void HMAC_Base::TruncatedFinal(byte *mac, size_t size)
+{
+ ThrowIfInvalidTruncatedSize(size);
+
+ HashTransformation &hash = AccessHash();
+
+ if (!m_innerHashKeyed)
+ KeyInnerHash();
+ hash.Final(AccessInnerHash());
+
+ hash.Update(AccessOpad(), hash.BlockSize());
+ hash.Update(AccessInnerHash(), hash.DigestSize());
+ hash.TruncatedFinal(mac, size);
+
+ m_innerHashKeyed = false;
+}
+
+NAMESPACE_END
+
+#endif