| /* |
| * Copyright(C) 2006 Cameron Rich |
| * |
| * This library is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Lesser General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public License |
| * along with this library; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| /** |
| * AES implementation - this is a small code version. There are much faster |
| * versions around but they are much larger in size (i.e. they use large |
| * submix tables). |
| */ |
| |
| #include <string.h> |
| #include "crypto.h" |
| |
| /* all commented out in skeleton mode */ |
| #ifndef CONFIG_SSL_SKELETON_MODE |
| |
| #define rot1(x) (((x) << 24) | ((x) >> 8)) |
| #define rot2(x) (((x) << 16) | ((x) >> 16)) |
| #define rot3(x) (((x) << 8) | ((x) >> 24)) |
| |
| /* |
| * This cute trick does 4 'mul by two' at once. Stolen from |
| * Dr B. R. Gladman <brg@gladman.uk.net> but I'm sure the u-(u>>7) is |
| * a standard graphics trick |
| * The key to this is that we need to xor with 0x1b if the top bit is set. |
| * a 1xxx xxxx 0xxx 0xxx First we mask the 7bit, |
| * b 1000 0000 0000 0000 then we shift right by 7 putting the 7bit in 0bit, |
| * c 0000 0001 0000 0000 we then subtract (c) from (b) |
| * d 0111 1111 0000 0000 and now we and with our mask |
| * e 0001 1011 0000 0000 |
| */ |
| #define mt 0x80808080 |
| #define ml 0x7f7f7f7f |
| #define mh 0xfefefefe |
| #define mm 0x1b1b1b1b |
| #define mul2(x,t) ((t)=((x)&mt), \ |
| ((((x)+(x))&mh)^(((t)-((t)>>7))&mm))) |
| |
| #define inv_mix_col(x,f2,f4,f8,f9) (\ |
| (f2)=mul2(x,f2), \ |
| (f4)=mul2(f2,f4), \ |
| (f8)=mul2(f4,f8), \ |
| (f9)=(x)^(f8), \ |
| (f8)=((f2)^(f4)^(f8)), \ |
| (f2)^=(f9), \ |
| (f4)^=(f9), \ |
| (f8)^=rot3(f2), \ |
| (f8)^=rot2(f4), \ |
| (f8)^rot1(f9)) |
| |
| /* some macros to do endian independent byte extraction */ |
| #define n2l(c,l) l=ntohl(*c); c++ |
| #define l2n(l,c) *c++=htonl(l) |
| |
| /* |
| * AES S-box |
| */ |
| static const uint8_t aes_sbox[256] = |
| { |
| 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, |
| }; |
| |
| /* |
| * AES is-box |
| */ |
| static const uint8_t aes_isbox[256] = |
| { |
| 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 unsigned char Rcon[30]= |
| { |
| 0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80, |
| 0x1b,0x36,0x6c,0xd8,0xab,0x4d,0x9a,0x2f, |
| 0x5e,0xbc,0x63,0xc6,0x97,0x35,0x6a,0xd4, |
| 0xb3,0x7d,0xfa,0xef,0xc5,0x91, |
| }; |
| |
| /* Perform doubling in Galois Field GF(2^8) using the irreducible polynomial |
| x^8+x^4+x^3+x+1 */ |
| static unsigned char AES_xtime(uint32_t x) |
| { |
| return x = (x&0x80) ? (x<<1)^0x1b : x<<1; |
| } |
| |
| /** |
| * Set up AES with the key/iv and cipher size. |
| */ |
| void AES_set_key(AES_CTX *ctx, const uint8_t *key, |
| const uint8_t *iv, AES_MODE mode) |
| { |
| int i, ii; |
| uint32_t *W, tmp, tmp2; |
| const unsigned char *ip; |
| int words; |
| |
| switch (mode) |
| { |
| case AES_MODE_128: |
| i = 10; |
| words = 4; |
| break; |
| |
| case AES_MODE_256: |
| i = 14; |
| words = 8; |
| break; |
| |
| default: /* fail silently */ |
| return; |
| } |
| |
| ctx->rounds = i; |
| ctx->key_size = words; |
| W = ctx->ks; |
| for (i = 0; i < words; i+=2) |
| { |
| W[i+0]= ((uint32_t)key[ 0]<<24)| |
| ((uint32_t)key[ 1]<<16)| |
| ((uint32_t)key[ 2]<< 8)| |
| ((uint32_t)key[ 3] ); |
| W[i+1]= ((uint32_t)key[ 4]<<24)| |
| ((uint32_t)key[ 5]<<16)| |
| ((uint32_t)key[ 6]<< 8)| |
| ((uint32_t)key[ 7] ); |
| key += 8; |
| } |
| |
| ip = Rcon; |
| ii = 4 * (ctx->rounds+1); |
| for (i = words; i<ii; i++) |
| { |
| tmp = W[i-1]; |
| |
| if ((i % words) == 0) |
| { |
| tmp2 =(uint32_t)aes_sbox[(tmp )&0xff]<< 8; |
| tmp2|=(uint32_t)aes_sbox[(tmp>> 8)&0xff]<<16; |
| tmp2|=(uint32_t)aes_sbox[(tmp>>16)&0xff]<<24; |
| tmp2|=(uint32_t)aes_sbox[(tmp>>24) ]; |
| tmp=tmp2^(((unsigned int)*ip)<<24); |
| ip++; |
| } |
| |
| if ((words == 8) && ((i % words) == 4)) |
| { |
| tmp2 =(uint32_t)aes_sbox[(tmp )&0xff] ; |
| tmp2|=(uint32_t)aes_sbox[(tmp>> 8)&0xff]<< 8; |
| tmp2|=(uint32_t)aes_sbox[(tmp>>16)&0xff]<<16; |
| tmp2|=(uint32_t)aes_sbox[(tmp>>24) ]<<24; |
| tmp=tmp2; |
| } |
| |
| W[i]=W[i-words]^tmp; |
| } |
| |
| /* copy the iv across */ |
| memcpy(ctx->iv, iv, 16); |
| } |
| |
| /** |
| * Change a key for decryption. |
| */ |
| void AES_convert_key(AES_CTX *ctx) |
| { |
| int i; |
| uint32_t *k,w,t1,t2,t3,t4; |
| |
| k = ctx->ks; |
| k += 4; |
| |
| for (i=ctx->rounds*4; i>4; i--) |
| { |
| w= *k; |
| w = inv_mix_col(w,t1,t2,t3,t4); |
| *k++ =w; |
| } |
| } |
| |
| #if 0 |
| /** |
| * Encrypt a byte sequence (with a block size 16) using the AES cipher. |
| */ |
| void AES_cbc_encrypt(AES_CTX *ctx, const uint8_t *msg, uint8_t *out, int length) |
| { |
| uint32_t tin0, tin1, tin2, tin3; |
| uint32_t tout0, tout1, tout2, tout3; |
| uint32_t tin[4]; |
| uint32_t *iv = (uint32_t *)ctx->iv; |
| uint32_t *msg_32 = (uint32_t *)msg; |
| uint32_t *out_32 = (uint32_t *)out; |
| |
| n2l(iv, tout0); |
| n2l(iv, tout1); |
| n2l(iv, tout2); |
| n2l(iv, tout3); |
| iv -= 4; |
| |
| for (length -= 16; length >= 0; length -= 16) |
| { |
| n2l(msg_32, tin0); |
| n2l(msg_32, tin1); |
| n2l(msg_32, tin2); |
| n2l(msg_32, tin3); |
| tin[0] = tin0^tout0; |
| tin[1] = tin1^tout1; |
| tin[2] = tin2^tout2; |
| tin[3] = tin3^tout3; |
| |
| AES_encrypt(ctx, tin); |
| |
| tout0 = tin[0]; |
| l2n(tout0, out_32); |
| tout1 = tin[1]; |
| l2n(tout1, out_32); |
| tout2 = tin[2]; |
| l2n(tout2, out_32); |
| tout3 = tin[3]; |
| l2n(tout3, out_32); |
| } |
| |
| l2n(tout0, iv); |
| l2n(tout1, iv); |
| l2n(tout2, iv); |
| l2n(tout3, iv); |
| } |
| |
| /** |
| * Decrypt a byte sequence (with a block size 16) using the AES cipher. |
| */ |
| void AES_cbc_decrypt(AES_CTX *ctx, const uint8_t *msg, uint8_t *out, int length) |
| { |
| uint32_t tin0, tin1, tin2, tin3; |
| uint32_t xor0,xor1,xor2,xor3; |
| uint32_t tout0,tout1,tout2,tout3; |
| uint32_t data[4]; |
| uint32_t *iv = (uint32_t *)ctx->iv; |
| uint32_t *msg_32 = (uint32_t *)msg; |
| uint32_t *out_32 = (uint32_t *)out; |
| |
| n2l(iv ,xor0); |
| n2l(iv, xor1); |
| n2l(iv, xor2); |
| n2l(iv, xor3); |
| iv -= 4; |
| |
| for (length-=16; length >= 0; length -= 16) |
| { |
| n2l(msg_32, tin0); |
| n2l(msg_32, tin1); |
| n2l(msg_32, tin2); |
| n2l(msg_32, tin3); |
| |
| data[0] = tin0; |
| data[1] = tin1; |
| data[2] = tin2; |
| data[3] = tin3; |
| |
| AES_decrypt(ctx, data); |
| |
| tout0 = data[0]^xor0; |
| tout1 = data[1]^xor1; |
| tout2 = data[2]^xor2; |
| tout3 = data[3]^xor3; |
| |
| xor0 = tin0; |
| xor1 = tin1; |
| xor2 = tin2; |
| xor3 = tin3; |
| |
| l2n(tout0, out_32); |
| l2n(tout1, out_32); |
| l2n(tout2, out_32); |
| l2n(tout3, out_32); |
| } |
| |
| l2n(xor0, iv); |
| l2n(xor1, iv); |
| l2n(xor2, iv); |
| l2n(xor3, iv); |
| } |
| #endif |
| |
| /** |
| * Encrypt a single block (16 bytes) of data |
| */ |
| void AES_encrypt(const AES_CTX *ctx, uint32_t *data) |
| { |
| /* To make this code smaller, generate the sbox entries on the fly. |
| * This will have a really heavy effect upon performance. |
| */ |
| uint32_t tmp[4]; |
| uint32_t tmp1, old_a0, a0, a1, a2, a3, row; |
| int curr_rnd; |
| int rounds = ctx->rounds; |
| const uint32_t *k = ctx->ks; |
| |
| /* Pre-round key addition */ |
| for (row = 0; row < 4; row++) |
| { |
| data[row] ^= *(k++); |
| } |
| |
| /* Encrypt one block. */ |
| for (curr_rnd = 0; curr_rnd < rounds; curr_rnd++) |
| { |
| /* Perform ByteSub and ShiftRow operations together */ |
| for (row = 0; row < 4; row++) |
| { |
| a0 = (uint32_t)aes_sbox[(data[row%4]>>24)&0xFF]; |
| a1 = (uint32_t)aes_sbox[(data[(row+1)%4]>>16)&0xFF]; |
| a2 = (uint32_t)aes_sbox[(data[(row+2)%4]>>8)&0xFF]; |
| a3 = (uint32_t)aes_sbox[(data[(row+3)%4])&0xFF]; |
| |
| /* Perform MixColumn iff not last round */ |
| if (curr_rnd < (rounds - 1)) |
| { |
| tmp1 = a0 ^ a1 ^ a2 ^ a3; |
| old_a0 = a0; |
| |
| a0 ^= tmp1 ^ AES_xtime(a0 ^ a1); |
| a1 ^= tmp1 ^ AES_xtime(a1 ^ a2); |
| a2 ^= tmp1 ^ AES_xtime(a2 ^ a3); |
| a3 ^= tmp1 ^ AES_xtime(a3 ^ old_a0); |
| |
| } |
| |
| tmp[row] = ((a0 << 24) | (a1 << 16) | (a2 << 8) | a3); |
| } |
| |
| /* KeyAddition - note that it is vital that this loop is separate from |
| the MixColumn operation, which must be atomic...*/ |
| for (row = 0; row < 4; row++) |
| { |
| data[row] = tmp[row] ^ *(k++); |
| } |
| } |
| } |
| |
| /** |
| * Decrypt a single block (16 bytes) of data |
| */ |
| void AES_decrypt(const AES_CTX *ctx, uint32_t *data) |
| { |
| uint32_t tmp[4]; |
| uint32_t xt0,xt1,xt2,xt3,xt4,xt5,xt6; |
| uint32_t a0, a1, a2, a3, row; |
| int curr_rnd; |
| int rounds = ctx->rounds; |
| uint32_t *k = (uint32_t*)ctx->ks + ((rounds+1)*4); |
| |
| /* pre-round key addition */ |
| for (row=4; row > 0;row--) |
| { |
| data[row-1] ^= *(--k); |
| } |
| |
| /* Decrypt one block */ |
| for (curr_rnd=0; curr_rnd < rounds; curr_rnd++) |
| { |
| /* Perform ByteSub and ShiftRow operations together */ |
| for (row = 4; row > 0; row--) |
| { |
| a0 = aes_isbox[(data[(row+3)%4]>>24)&0xFF]; |
| a1 = aes_isbox[(data[(row+2)%4]>>16)&0xFF]; |
| a2 = aes_isbox[(data[(row+1)%4]>>8)&0xFF]; |
| a3 = aes_isbox[(data[row%4])&0xFF]; |
| |
| /* Perform MixColumn iff not last round */ |
| if (curr_rnd<(rounds-1)) |
| { |
| /* The MDS cofefficients (0x09, 0x0B, 0x0D, 0x0E) |
| are quite large compared to encryption; this |
| operation slows decryption down noticeably. */ |
| xt0 = AES_xtime(a0^a1); |
| xt1 = AES_xtime(a1^a2); |
| xt2 = AES_xtime(a2^a3); |
| xt3 = AES_xtime(a3^a0); |
| xt4 = AES_xtime(xt0^xt1); |
| xt5 = AES_xtime(xt1^xt2); |
| xt6 = AES_xtime(xt4^xt5); |
| |
| xt0 ^= a1^a2^a3^xt4^xt6; |
| xt1 ^= a0^a2^a3^xt5^xt6; |
| xt2 ^= a0^a1^a3^xt4^xt6; |
| xt3 ^= a0^a1^a2^xt5^xt6; |
| tmp[row-1] = ((xt0<<24)|(xt1<<16)|(xt2<<8)|xt3); |
| } |
| else |
| tmp[row-1] = ((a0<<24)|(a1<<16)|(a2<<8)|a3); |
| } |
| |
| for (row = 4; row > 0; row--) |
| { |
| data[row-1] = tmp[row-1] ^ *(--k); |
| } |
| } |
| } |
| |
| #endif |
