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Diffstat (limited to 'libs/nixio/axTLS/crypto/aes.c')
| -rw-r--r-- | libs/nixio/axTLS/crypto/aes.c | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/libs/nixio/axTLS/crypto/aes.c b/libs/nixio/axTLS/crypto/aes.c new file mode 100644 index 000000000..038a45bd8 --- /dev/null +++ b/libs/nixio/axTLS/crypto/aes.c @@ -0,0 +1,456 @@ +/* + * Copyright (c) 2007, Cameron Rich + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of the axTLS project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * 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)) + +/* + * 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, +}; + +/* ----- static functions ----- */ +static void AES_encrypt(const AES_CTX *ctx, uint32_t *data); +static void AES_decrypt(const AES_CTX *ctx, uint32_t *data); + +/* 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; + } +} + +/** + * 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) +{ + int i; + uint32_t tin[4], tout[4], iv[4]; + + memcpy(iv, ctx->iv, AES_IV_SIZE); + for (i = 0; i < 4; i++) + tout[i] = ntohl(iv[i]); + + for (length -= AES_BLOCKSIZE; length >= 0; length -= AES_BLOCKSIZE) + { + uint32_t msg_32[4]; + uint32_t out_32[4]; + memcpy(msg_32, msg, AES_BLOCKSIZE); + msg += AES_BLOCKSIZE; + + for (i = 0; i < 4; i++) + tin[i] = ntohl(msg_32[i])^tout[i]; + + AES_encrypt(ctx, tin); + + for (i = 0; i < 4; i++) + { + tout[i] = tin[i]; + out_32[i] = htonl(tout[i]); + } + + memcpy(out, out_32, AES_BLOCKSIZE); + out += AES_BLOCKSIZE; + } + + for (i = 0; i < 4; i++) + iv[i] = htonl(tout[i]); + memcpy(ctx->iv, iv, AES_IV_SIZE); +} + +/** + * 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) +{ + int i; + uint32_t tin[4], xor[4], tout[4], data[4], iv[4]; + + memcpy(iv, ctx->iv, AES_IV_SIZE); + for (i = 0; i < 4; i++) + xor[i] = ntohl(iv[i]); + + for (length -= 16; length >= 0; length -= 16) + { + uint32_t msg_32[4]; + uint32_t out_32[4]; + memcpy(msg_32, msg, AES_BLOCKSIZE); + msg += AES_BLOCKSIZE; + + for (i = 0; i < 4; i++) + { + tin[i] = ntohl(msg_32[i]); + data[i] = tin[i]; + } + + AES_decrypt(ctx, data); + + for (i = 0; i < 4; i++) + { + tout[i] = data[i]^xor[i]; + xor[i] = tin[i]; + out_32[i] = htonl(tout[i]); + } + + memcpy(out, out_32, AES_BLOCKSIZE); + out += AES_BLOCKSIZE; + } + + for (i = 0; i < 4; i++) + iv[i] = htonl(xor[i]); + memcpy(ctx->iv, iv, AES_IV_SIZE); +} + +/** + * Encrypt a single block (16 bytes) of data + */ +static 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 + */ +static 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; + const uint32_t *k = 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 |