Diff: SHA1.cpp

Revision:

0:7a1237bd2d13

Child:

1:14a7cea431aa

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SHA1.cpp	Sat Sep 07 23:47:28 2013 +0000
@@ -0,0 +1,235 @@
+#include "SHA1.h"
+#include <string.h>
+
+static uint32_t f(uint8_t t, uint32_t B, uint32_t C, uint32_t D)
+{
+    if(t <= 19)
+        return (B & C) | ((~B) & D);
+    else if(t <= 39)
+        return B ^ C ^ D;
+    else if(t <= 59)
+        return (B & C) | (B & D) | (C & D);
+    else if(t <= 79)
+        return B ^ C ^ D;
+    
+    return 0;
+}
+
+static uint32_t K(uint8_t t)
+{
+    if(t <= 19)
+      return 0x5A827999;
+    else if(t <= 39)
+      return 0x6ED9EBA1;
+    else if(t <= 59)
+      return 0x8F1BBCDC;
+    else if(t <= 79)
+      return 0xCA62C1D6;
+    
+    return 0;
+}
+
+static uint32_t rotLeft(uint32_t w, uint8_t n)
+{
+    return (w << n) | (w >> (32-n));
+}
+
+static const uint32_t H0 = 0x67452301;
+static const uint32_t H1 = 0xEFCDAB89;
+static const uint32_t H2 = 0x98BADCFE;
+static const uint32_t H3 = 0x10325476;
+static const uint32_t H4 = 0xC3D2E1F0;
+static const uint32_t MASK = 0x0000000F;
+
+
+SHA1::SHA1():
+HashAlgorithm(),
+h0(H0),
+h1(H1),
+h2(H2),
+h3(H3),
+h4(H4),
+totalBufferLength(0),
+buffer(),
+bufferLength(0)
+{
+}
+
+uint8_t SHA1::outputSize() const
+{
+    return 20;
+}
+
+void SHA1::add(uint8_t *in, uint32_t length)
+{
+    if(length < 64-bufferLength)
+    {
+        memcpy(&buffer[bufferLength], in, length);
+        bufferLength += length;
+        totalBufferLength += length;
+        return;
+    }
+    int offset = 64-bufferLength;
+    memcpy(&buffer[bufferLength], in, offset);
+    computeBlock(&h0,&h1,&h2,&h3,&h4, buffer);
+    while(length-offset > 64)
+    {
+        memcpy(buffer, &in[offset], 64);
+        computeBlock(&h0,&h1,&h2,&h3,&h4, buffer);
+        offset += 64;
+    }
+    if(offset > length)
+        offset -= 64;
+    bufferLength = length - offset;
+    memcpy(buffer, &in[offset], bufferLength);
+    totalBufferLength += length;
+}
+
+void SHA1::computeDigest(uint8_t *digest)
+{
+    uint16_t padding;
+    if(totalBufferLength % 64 < 56)
+        padding = 56 - (totalBufferLength % 64);
+    else
+        padding = 56 + (64 - (totalBufferLength % 64));
+    uint8_t val = 0x80;
+    add(&val, 1);
+    val = 0;
+    for(int i = 0; i < padding-1; ++i)
+        add(&val,1);
+    totalBufferLength -= padding;
+    uint64_t lengthBit = totalBufferLength * 8;
+    uint32_t lengthBitLow = lengthBit;
+    uint32_t lengthBitHigh = lengthBit >> 32;
+    uint8_t l[4];
+
+    l[0] = lengthBitHigh >> 24;
+    l[1] = lengthBitHigh >> 16;
+    l[2] = lengthBitHigh >> 8;
+    l[3] = lengthBitHigh;
+    add(l, 4);
+    l[0] = lengthBitLow >> 24;
+    l[1] = lengthBitLow >> 16;
+    l[2] = lengthBitLow >> 8;
+    l[3] = lengthBitLow;
+    add(l, 4);
+
+    digest[0] = h0 >> 24;
+    digest[1] = h0 >> 16;
+    digest[2] = h0 >> 8;
+    digest[3] = h0;
+    digest[4] = h1 >> 24;
+    digest[5] = h1 >> 16;
+    digest[6] = h1 >> 8;
+    digest[7] = h1;
+    digest[8] = h2 >> 24;
+    digest[9] = h2 >> 16;
+    digest[10] = h2 >> 8;
+    digest[11] = h2;
+    digest[12] = h3 >> 24;
+    digest[13] = h3 >> 16;
+    digest[14] = h3 >> 8;
+    digest[15] = h3;
+    digest[16] = h4 >> 24;
+    digest[17] = h4 >> 16;
+    digest[18] = h4 >> 8;
+    digest[19] = h4;
+    
+    // reset state
+    h0 = H0;
+    h1 = H1;
+    h2 = H2;
+    h3 = H3;
+    h4 = H4;
+    totalBufferLength = 0;
+    bufferLength = 0;
+}
+
+void SHA1::computeBlock(uint32_t *h02, uint32_t *h12, uint32_t *h22, uint32_t *h32, uint32_t *h42, uint8_t *buffer)
+{
+    uint32_t w[16];
+    for(int j = 0; j < 16; ++j)
+        w[j] = (buffer[j*4] << 24) | (buffer[j*4+1] << 16) | (buffer[j*4+2] << 8) | buffer[j*4+3];
+    
+    uint32_t a = *h02, b = *h12, c = *h22, d = *h32, e = *h42;
+    for(uint8_t t = 0; t < 80; ++t)
+    {
+        uint32_t s = t & MASK;
+        if(t >= 16)
+        {
+            w[s%16] = w[((s + 13) & MASK)%16] ^ w[((s + 8) & MASK)%16] ^ w[((s + 2) & MASK)%16] ^ w[s%16];
+            w[s%16] = rotLeft(w[s%16], 1);
+        }
+        
+        uint32_t temp = rotLeft(a, 5) + f(t, b, c, d) + e + w[s%16] + K(t);
+        e = d;
+        d = c;
+        c = rotLeft(b,30);
+        b = a;
+        a = temp;
+    }
+    *h02 += a;
+    *h12 += b;
+    *h22 += c;
+    *h32 += d;
+    *h42 += e;
+}
+
+
+
+/* method 2 */
+void SHA1::computeDigest(uint8_t *digest, uint8_t *in, uint32_t length)
+{
+    uint16_t padding;
+    if(length % 64 < 56)
+        padding = 56 - (length % 64);
+    else
+        padding = 56 + (64 - (length % 64));
+    uint32_t totalLength = length + padding + 8;
+    uint8_t *buffer = new uint8_t[totalLength];
+    memcpy(buffer, in, length);
+    buffer[length] = 0x80;
+    memset(&buffer[length+1], 0, padding-1);
+    uint64_t lengthBit = length * 8;
+    uint32_t lengthBitLow = lengthBit;
+    uint32_t lengthBitHigh = lengthBit >> 32;
+    uint8_t l[4];
+    l[0] = lengthBitLow >> 24;
+    l[1] = lengthBitLow >> 16;
+    l[2] = lengthBitLow >> 8;
+    l[3] = lengthBitLow;
+    memcpy(&buffer[length+padding+4], l, 4);
+    l[0] = lengthBitHigh >> 24;
+    l[1] = lengthBitHigh >> 16;
+    l[2] = lengthBitHigh >> 8;
+    l[3] = lengthBitHigh;
+    memcpy(&buffer[length+padding], l, 4);
+    
+    uint32_t h0 = H0, h1 = H1, h2 = H2, h3 = H3, h4 = H4;
+    for(int i = 0; i < totalLength/64;  ++i)
+        computeBlock(&h0,&h1,&h2,&h3,&h4, &buffer[64*i]);
+
+    delete[] buffer;
+    
+    digest[0] = h0 >> 24;
+    digest[1] = h0 >> 16;
+    digest[2] = h0 >> 8;
+    digest[3] = h0;
+    digest[4] = h1 >> 24;
+    digest[5] = h1 >> 16;
+    digest[6] = h1 >> 8;
+    digest[7] = h1;
+    digest[8] = h2 >> 24;
+    digest[9] = h2 >> 16;
+    digest[10] = h2 >> 8;
+    digest[11] = h2;
+    digest[12] = h3 >> 24;
+    digest[13] = h3 >> 16;
+    digest[14] = h3 >> 8;
+    digest[15] = h3;
+    digest[16] = h4 >> 24;
+    digest[17] = h4 >> 16;
+    digest[18] = h4 >> 8;
+    digest[19] = h4;
+}
+