Diff: cipher/AES.cpp

Revision:

7:2dbbdfb08123

Parent:

2:473bac39ae7c

Child:

8:a090264e9b2d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cipher/AES.cpp	Sat Sep 14 18:21:32 2013 +0000
@@ -0,0 +1,294 @@
+#include "AES.h"
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static const uint8_t sbox[] =
+{
+   0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
+   0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
+   0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
+   0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
+   0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
+   0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
+   0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
+   0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
+   0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
+   0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
+   0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
+   0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
+   0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
+   0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
+   0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
+   0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16
+};
+
+static const uint8_t inv_s[] = 
+{
+   0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
+   0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
+   0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
+   0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
+   0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
+   0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
+   0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
+   0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
+   0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
+   0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
+   0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
+   0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
+   0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
+   0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
+   0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
+   0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D
+};
+
+
+static const uint32_t rcon[10]=
+{
+    0x01000000, 0x02000000, 0x04000000, 0x08000000,
+    0x10000000, 0x20000000, 0x40000000, 0x80000000,
+    0x1B000000, 0x36000000
+};
+
+AES::AES(const AES_TYPE t, uint8_t *key):
+state()
+{
+    switch(t)
+    {
+        case AES_128:
+            nr = 10;
+            nk = 4;
+        break;
+        
+        case AES_192:
+            nr = 12;
+            nk = 6;
+        break;
+        
+        case AES_256:
+            nr = 14;
+            nk = 8;
+        break;
+    }
+    
+    keyExpansion(key);
+}
+
+void AES::keyExpansion(uint8_t *key)
+{
+    uint32_t temp;
+    int i = 0;
+    
+    while(i < nk)
+    {
+        w[i] = (key[4*i] << 24) + (key[4*i+1] << 16) + (key[4*i+2] << 8) + key[4*i+3];
+        i++;
+    }
+    i = nk;
+    while(i < 4*(nr+1))
+    {
+        temp = w[i-1];
+        if(i % nk == 0)
+        {
+            temp = rotWord(temp);
+            temp = subWord(temp);
+            temp ^= rcon[i/nk-1];
+        }
+        else if(nk > 6 && i % nk == 4)
+            temp = subWord(temp);
+        w[i] = w[i-nk] ^ temp;
+        i++;
+    }
+}
+
+uint32_t AES::rotWord(uint32_t w)
+{
+    return (w << 8) + (w >> 24);
+}
+
+uint32_t AES::invRotWord(uint32_t w)
+{
+    return (w >> 8) + (w << 24);
+}
+
+uint32_t AES::subWord(uint32_t w)
+{
+    uint32_t out = 0;
+    for(int i = 0; i < 4; ++i)
+    {
+        uint8_t temp = (w & 0xFF);
+        out |= (sbox[temp] << (8*i));
+        w = (w >> 8);
+    }
+    return out;
+}
+
+void AES::subBytes()
+{
+    for(int i = 0; i < 16; ++i)
+        state[i] = sbox[state[i]];
+}
+
+void AES::invSubBytes()
+{
+    for(int i = 0; i < 16; ++i)
+        state[i] = inv_s[state[i]];
+}
+
+void AES::shiftRows()
+{
+    for(int r = 0; r < 4; ++r)
+    {   
+        uint32_t temp = (state[r] << 24) + (state[r+4] << 16) + (state[r+8] << 8) + state[r+12];
+        int i = r;
+        while(i > 0)
+        {
+            temp = rotWord(temp);
+            --i;
+        }
+        state[r] = temp >> 24;
+        state[r+4] = temp >> 16;
+        state[r+8] = temp >> 8;
+        state[r+12] = temp;
+    }
+}
+
+void AES::invShiftRows()
+{
+    for(int r = 0; r < 4; ++r)
+    {
+        uint32_t temp = (state[r] << 24) + (state[r+4] << 16) + (state[r+8] << 8) + state[r+12];
+        int i = r;
+        while(i > 0)
+        {
+            temp = invRotWord(temp);
+            --i;
+        }
+        state[r] = temp >> 24;
+        state[r+4] = temp >> 16;
+        state[r+8] = temp >> 8;
+        state[r+12] = temp;
+    }
+}
+
+/* Multiply two numbers in the GF(2^8) finite field defined 
+ * by the polynomial x^8 + x^4 + x^3 + x + 1 */
+uint8_t gmul(uint8_t a, uint8_t b) 
+{
+    uint8_t p = 0;
+    uint8_t counter;
+    uint8_t carry;
+    for (counter = 0; counter < 8; counter++) {
+        if (b & 1) 
+            p ^= a;
+        carry = (a & 0x80);
+        a <<= 1;
+        if (carry) 
+            a ^= 0x001B; /* what x^8 is modulo x^8 + x^4 + x^3 + x^2 + 1 */
+        b >>= 1;
+    }
+    return p;
+}
+
+void AES::mul(uint8_t *r) 
+{
+    uint8_t tmp[4];
+    memcpy(tmp, r, 4);
+    r[0] = gmul(tmp[0],2) ^ gmul(tmp[1],3) ^ tmp[2] ^ tmp[3];
+    r[1] = tmp[0] ^ gmul(tmp[1],2) ^ gmul(tmp[2],3) ^ tmp[3];
+    r[2] = tmp[0] ^ tmp[1] ^ gmul(tmp[2],2) ^ gmul(tmp[3],3);
+    r[3] = gmul(tmp[0],3) ^ tmp[1] ^ tmp[2] ^ gmul(tmp[3],2);
+}
+
+void AES::invMul(uint8_t *r)
+{
+    uint8_t tmp[4];
+    memcpy(tmp, r, 4);
+    r[0] = gmul(tmp[0],0x0e) ^ gmul(tmp[1],0x0b) ^ gmul(tmp[2],0x0d) ^ gmul(tmp[3],9);
+    r[1] = gmul(tmp[0],9) ^ gmul(tmp[1],0x0e) ^ gmul(tmp[2],0x0b) ^ gmul(tmp[3],0x0d);
+    r[2] = gmul(tmp[0],0x0d) ^ gmul(tmp[1],9) ^ gmul(tmp[2],0x0e) ^ gmul(tmp[3],0x0b);
+    r[3] = gmul(tmp[0],0x0b) ^ gmul(tmp[1],0x0d) ^ gmul(tmp[2],9) ^ gmul(tmp[3],0x0e);
+}
+
+void AES::mixColumns()
+{
+    for(int c = 0; c < 4; ++c)
+        mul(&state[4*c]);
+}
+
+void AES::invMixColumns()
+{
+    for(int c = 0; c < 4; ++c)
+        invMul(&state[4*c]);
+}
+
+void AES::addRoundKey(int round)
+{
+    for(int c = 0; c < 4; ++c)
+    {
+        uint32_t temp = (state[4*c] << 24) + (state[4*c+1] << 16) + (state[4*c+2] << 8) + state[4*c+3];
+        temp ^= w[round*4+c];
+        state[4*c] = temp >> 24;
+        state[4*c+1] = temp >> 16;
+        state[4*c+2] = temp >> 8;
+        state[4*c+3] = temp;
+    }
+}
+
+void AES::decryptBlock(uint8_t *out, uint8_t *in)
+{
+    memcpy(state,in,16);
+    
+    addRoundKey(nr);
+    
+    for(int round = nr-1; round > 0; --round)
+    {
+        invShiftRows();
+        invSubBytes();
+        addRoundKey(round);
+        invMixColumns();
+    }
+    invShiftRows();
+    invSubBytes();
+    addRoundKey(0);
+    
+    memcpy(out, state, 16);
+}
+
+void AES::encryptBlock(uint8_t *out, uint8_t *in)
+{
+    memcpy(state,in,16);
+    
+    addRoundKey(0);
+    
+    for(int round = 1; round < nr; ++round)
+    {
+        subBytes();
+        shiftRows();
+        mixColumns();
+        addRoundKey(round);
+    }
+    subBytes();
+    shiftRows();
+    addRoundKey(nr);
+    
+    memcpy(out, state, 16);
+}
+
+void AES::encrypt(uint8_t *out, uint8_t *in, uint32_t length)
+{
+    for(uint32_t i = 0; i < length; i+=16)
+        encryptBlock(&out[i], &in[i]);
+}
+
+void AES::decrypt(uint8_t *out, uint8_t *in, uint32_t length)
+{
+    for(uint32_t i = 0; i < length; i+=16)
+        decryptBlock(&out[i], &in[i]);
+}
+
+uint32_t AES::getBlockSize() const
+{
+    return 16;
+}