summaryrefslogtreecommitdiff
path: root/axTLS/src/crypto/aes.c
diff options
context:
space:
mode:
Diffstat (limited to 'axTLS/src/crypto/aes.c')
-rw-r--r--axTLS/src/crypto/aes.c457
1 files changed, 457 insertions, 0 deletions
diff --git a/axTLS/src/crypto/aes.c b/axTLS/src/crypto/aes.c
new file mode 100644
index 0000000..9b07e27
--- /dev/null
+++ b/axTLS/src/crypto/aes.c
@@ -0,0 +1,457 @@
+/*
+ * 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 "os_port.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&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