p7zip/CPP/7zip/Crypto/Pbkdf2HmacSha1.cpp
2017-10-11 12:35:36 +02:00

98 lines
2.0 KiB
C++

// Pbkdf2HmacSha1.cpp
#include "StdAfx.h"
#include "../../../C/CpuArch.h"
#include "HmacSha1.h"
namespace NCrypto {
namespace NSha1 {
void Pbkdf2Hmac(const Byte *pwd, size_t pwdSize,
const Byte *salt, size_t saltSize,
UInt32 numIterations,
Byte *key, size_t keySize)
{
CHmac baseCtx;
baseCtx.SetKey(pwd, pwdSize);
for (UInt32 i = 1; keySize != 0; i++)
{
CHmac ctx = baseCtx;
ctx.Update(salt, saltSize);
Byte u[kDigestSize];
SetBe32(u, i);
ctx.Update(u, 4);
ctx.Final(u, kDigestSize);
const unsigned curSize = (keySize < kDigestSize) ? (unsigned)keySize : kDigestSize;
unsigned s;
for (s = 0; s < curSize; s++)
key[s] = u[s];
for (UInt32 j = numIterations; j > 1; j--)
{
ctx = baseCtx;
ctx.Update(u, kDigestSize);
ctx.Final(u, kDigestSize);
for (s = 0; s < curSize; s++)
key[s] ^= u[s];
}
key += curSize;
keySize -= curSize;
}
}
void Pbkdf2Hmac32(const Byte *pwd, size_t pwdSize,
const UInt32 *salt, size_t saltSize,
UInt32 numIterations,
UInt32 *key, size_t keySize)
{
CHmac32 baseCtx;
baseCtx.SetKey(pwd, pwdSize);
for (UInt32 i = 1; keySize != 0; i++)
{
CHmac32 ctx = baseCtx;
ctx.Update(salt, saltSize);
UInt32 u[kNumDigestWords];
u[0] = i;
ctx.Update(u, 1);
ctx.Final(u, kNumDigestWords);
// Speed-optimized code start
ctx = baseCtx;
ctx.GetLoopXorDigest(u, numIterations - 1);
// Speed-optimized code end
const unsigned curSize = (keySize < kNumDigestWords) ? (unsigned)keySize : kNumDigestWords;
unsigned s;
for (s = 0; s < curSize; s++)
key[s] = u[s];
/*
// Default code start
for (UInt32 j = numIterations; j > 1; j--)
{
ctx = baseCtx;
ctx.Update(u, kNumDigestWords);
ctx.Final(u, kNumDigestWords);
for (s = 0; s < curSize; s++)
key[s] ^= u[s];
}
// Default code end
*/
key += curSize;
keySize -= curSize;
}
}
}}