Mercurial > dropbear
view libtomcrypt/src/ciphers/aes/aes.c @ 404:a588558bfc94
Fix potential null pointer dereference found by Klokwork
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Sat, 03 Feb 2007 09:58:14 +0000 |
parents | 1b9e69c058d2 |
children | 0cbe8f6dbf9e |
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://libtomcrypt.org */ /* AES implementation by Tom St Denis * * Derived from the Public Domain source code by --- * rijndael-alg-fst.c * * @version 3.0 (December 2000) * * Optimised ANSI C code for the Rijndael cipher (now AES) * * @author Vincent Rijmen <[email protected]> * @author Antoon Bosselaers <[email protected]> * @author Paulo Barreto <[email protected]> --- */ /** @file aes.c Implementation of AES */ #include "tomcrypt.h" #ifdef RIJNDAEL #ifndef ENCRYPT_ONLY #define SETUP rijndael_setup #define ECB_ENC rijndael_ecb_encrypt #define ECB_DEC rijndael_ecb_decrypt #define ECB_DONE rijndael_done #define ECB_TEST rijndael_test #define ECB_KS rijndael_keysize #if 0 const struct ltc_cipher_descriptor rijndael_desc = { "rijndael", 6, 16, 32, 16, 10, SETUP, ECB_ENC, ECB_DEC, ECB_TEST, ECB_DONE, ECB_KS, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; #endif const struct ltc_cipher_descriptor aes_desc = { "aes", 6, 16, 32, 16, 10, SETUP, ECB_ENC, ECB_DEC, ECB_TEST, ECB_DONE, ECB_KS, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; #else #define SETUP rijndael_enc_setup #define ECB_ENC rijndael_enc_ecb_encrypt #define ECB_KS rijndael_enc_keysize #define ECB_DONE rijndael_enc_done const struct ltc_cipher_descriptor rijndael_enc_desc = { "rijndael", 6, 16, 32, 16, 10, SETUP, ECB_ENC, NULL, NULL, ECB_DONE, ECB_KS, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; const struct ltc_cipher_descriptor aes_enc_desc = { "aes", 6, 16, 32, 16, 10, SETUP, ECB_ENC, NULL, NULL, ECB_DONE, ECB_KS, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; #endif #include "aes_tab.c" static ulong32 setup_mix(ulong32 temp) { return (Te4_3[byte(temp, 2)]) ^ (Te4_2[byte(temp, 1)]) ^ (Te4_1[byte(temp, 0)]) ^ (Te4_0[byte(temp, 3)]); } #ifndef ENCRYPT_ONLY #ifdef LTC_SMALL_CODE static ulong32 setup_mix2(ulong32 temp) { return Td0(255 & Te4[byte(temp, 3)]) ^ Td1(255 & Te4[byte(temp, 2)]) ^ Td2(255 & Te4[byte(temp, 1)]) ^ Td3(255 & Te4[byte(temp, 0)]); } #endif #endif /** Initialize the AES (Rijndael) block cipher @param key The symmetric key you wish to pass @param keylen The key length in bytes @param num_rounds The number of rounds desired (0 for default) @param skey The key in as scheduled by this function. @return CRYPT_OK if successful */ int SETUP(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) { int i, j; ulong32 temp, *rk; #ifndef ENCRYPT_ONLY ulong32 *rrk; #endif LTC_ARGCHK(key != NULL); LTC_ARGCHK(skey != NULL); if (keylen != 16 && keylen != 24 && keylen != 32) { return CRYPT_INVALID_KEYSIZE; } if (num_rounds != 0 && num_rounds != (10 + ((keylen/8)-2)*2)) { return CRYPT_INVALID_ROUNDS; } skey->rijndael.Nr = 10 + ((keylen/8)-2)*2; /* setup the forward key */ i = 0; rk = skey->rijndael.eK; LOAD32H(rk[0], key ); LOAD32H(rk[1], key + 4); LOAD32H(rk[2], key + 8); LOAD32H(rk[3], key + 12); if (keylen == 16) { j = 44; for (;;) { temp = rk[3]; rk[4] = rk[0] ^ setup_mix(temp) ^ rcon[i]; rk[5] = rk[1] ^ rk[4]; rk[6] = rk[2] ^ rk[5]; rk[7] = rk[3] ^ rk[6]; if (++i == 10) { break; } rk += 4; } } else if (keylen == 24) { j = 52; LOAD32H(rk[4], key + 16); LOAD32H(rk[5], key + 20); for (;;) { #ifdef _MSC_VER temp = skey->rijndael.eK[rk - skey->rijndael.eK + 5]; #else temp = rk[5]; #endif rk[ 6] = rk[ 0] ^ setup_mix(temp) ^ rcon[i]; rk[ 7] = rk[ 1] ^ rk[ 6]; rk[ 8] = rk[ 2] ^ rk[ 7]; rk[ 9] = rk[ 3] ^ rk[ 8]; if (++i == 8) { break; } rk[10] = rk[ 4] ^ rk[ 9]; rk[11] = rk[ 5] ^ rk[10]; rk += 6; } } else if (keylen == 32) { j = 60; LOAD32H(rk[4], key + 16); LOAD32H(rk[5], key + 20); LOAD32H(rk[6], key + 24); LOAD32H(rk[7], key + 28); for (;;) { #ifdef _MSC_VER temp = skey->rijndael.eK[rk - skey->rijndael.eK + 7]; #else temp = rk[7]; #endif rk[ 8] = rk[ 0] ^ setup_mix(temp) ^ rcon[i]; rk[ 9] = rk[ 1] ^ rk[ 8]; rk[10] = rk[ 2] ^ rk[ 9]; rk[11] = rk[ 3] ^ rk[10]; if (++i == 7) { break; } temp = rk[11]; rk[12] = rk[ 4] ^ setup_mix(RORc(temp, 8)); rk[13] = rk[ 5] ^ rk[12]; rk[14] = rk[ 6] ^ rk[13]; rk[15] = rk[ 7] ^ rk[14]; rk += 8; } } else { /* this can't happen */ return CRYPT_ERROR; } #ifndef ENCRYPT_ONLY /* setup the inverse key now */ rk = skey->rijndael.dK; rrk = skey->rijndael.eK + j - 4; /* apply the inverse MixColumn transform to all round keys but the first and the last: */ /* copy first */ *rk++ = *rrk++; *rk++ = *rrk++; *rk++ = *rrk++; *rk = *rrk; rk -= 3; rrk -= 3; for (i = 1; i < skey->rijndael.Nr; i++) { rrk -= 4; rk += 4; #ifdef LTC_SMALL_CODE temp = rrk[0]; rk[0] = setup_mix2(temp); temp = rrk[1]; rk[1] = setup_mix2(temp); temp = rrk[2]; rk[2] = setup_mix2(temp); temp = rrk[3]; rk[3] = setup_mix2(temp); #else temp = rrk[0]; rk[0] = Tks0[byte(temp, 3)] ^ Tks1[byte(temp, 2)] ^ Tks2[byte(temp, 1)] ^ Tks3[byte(temp, 0)]; temp = rrk[1]; rk[1] = Tks0[byte(temp, 3)] ^ Tks1[byte(temp, 2)] ^ Tks2[byte(temp, 1)] ^ Tks3[byte(temp, 0)]; temp = rrk[2]; rk[2] = Tks0[byte(temp, 3)] ^ Tks1[byte(temp, 2)] ^ Tks2[byte(temp, 1)] ^ Tks3[byte(temp, 0)]; temp = rrk[3]; rk[3] = Tks0[byte(temp, 3)] ^ Tks1[byte(temp, 2)] ^ Tks2[byte(temp, 1)] ^ Tks3[byte(temp, 0)]; #endif } /* copy last */ rrk -= 4; rk += 4; *rk++ = *rrk++; *rk++ = *rrk++; *rk++ = *rrk++; *rk = *rrk; #endif /* ENCRYPT_ONLY */ return CRYPT_OK; } /** Encrypts a block of text with AES @param pt The input plaintext (16 bytes) @param ct The output ciphertext (16 bytes) @param skey The key as scheduled */ #ifdef LTC_CLEAN_STACK static void _rijndael_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) #else void ECB_ENC(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) #endif { ulong32 s0, s1, s2, s3, t0, t1, t2, t3, *rk; int Nr, r; LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LTC_ARGCHK(skey != NULL); Nr = skey->rijndael.Nr; rk = skey->rijndael.eK; /* * map byte array block to cipher state * and add initial round key: */ LOAD32H(s0, pt ); s0 ^= rk[0]; LOAD32H(s1, pt + 4); s1 ^= rk[1]; LOAD32H(s2, pt + 8); s2 ^= rk[2]; LOAD32H(s3, pt + 12); s3 ^= rk[3]; #ifdef LTC_SMALL_CODE for (r = 0; ; r++) { rk += 4; t0 = Te0(byte(s0, 3)) ^ Te1(byte(s1, 2)) ^ Te2(byte(s2, 1)) ^ Te3(byte(s3, 0)) ^ rk[0]; t1 = Te0(byte(s1, 3)) ^ Te1(byte(s2, 2)) ^ Te2(byte(s3, 1)) ^ Te3(byte(s0, 0)) ^ rk[1]; t2 = Te0(byte(s2, 3)) ^ Te1(byte(s3, 2)) ^ Te2(byte(s0, 1)) ^ Te3(byte(s1, 0)) ^ rk[2]; t3 = Te0(byte(s3, 3)) ^ Te1(byte(s0, 2)) ^ Te2(byte(s1, 1)) ^ Te3(byte(s2, 0)) ^ rk[3]; if (r == Nr-2) { break; } s0 = t0; s1 = t1; s2 = t2; s3 = t3; } rk += 4; #else /* * Nr - 1 full rounds: */ r = Nr >> 1; for (;;) { t0 = Te0(byte(s0, 3)) ^ Te1(byte(s1, 2)) ^ Te2(byte(s2, 1)) ^ Te3(byte(s3, 0)) ^ rk[4]; t1 = Te0(byte(s1, 3)) ^ Te1(byte(s2, 2)) ^ Te2(byte(s3, 1)) ^ Te3(byte(s0, 0)) ^ rk[5]; t2 = Te0(byte(s2, 3)) ^ Te1(byte(s3, 2)) ^ Te2(byte(s0, 1)) ^ Te3(byte(s1, 0)) ^ rk[6]; t3 = Te0(byte(s3, 3)) ^ Te1(byte(s0, 2)) ^ Te2(byte(s1, 1)) ^ Te3(byte(s2, 0)) ^ rk[7]; rk += 8; if (--r == 0) { break; } s0 = Te0(byte(t0, 3)) ^ Te1(byte(t1, 2)) ^ Te2(byte(t2, 1)) ^ Te3(byte(t3, 0)) ^ rk[0]; s1 = Te0(byte(t1, 3)) ^ Te1(byte(t2, 2)) ^ Te2(byte(t3, 1)) ^ Te3(byte(t0, 0)) ^ rk[1]; s2 = Te0(byte(t2, 3)) ^ Te1(byte(t3, 2)) ^ Te2(byte(t0, 1)) ^ Te3(byte(t1, 0)) ^ rk[2]; s3 = Te0(byte(t3, 3)) ^ Te1(byte(t0, 2)) ^ Te2(byte(t1, 1)) ^ Te3(byte(t2, 0)) ^ rk[3]; } #endif /* * apply last round and * map cipher state to byte array block: */ s0 = (Te4_3[byte(t0, 3)]) ^ (Te4_2[byte(t1, 2)]) ^ (Te4_1[byte(t2, 1)]) ^ (Te4_0[byte(t3, 0)]) ^ rk[0]; STORE32H(s0, ct); s1 = (Te4_3[byte(t1, 3)]) ^ (Te4_2[byte(t2, 2)]) ^ (Te4_1[byte(t3, 1)]) ^ (Te4_0[byte(t0, 0)]) ^ rk[1]; STORE32H(s1, ct+4); s2 = (Te4_3[byte(t2, 3)]) ^ (Te4_2[byte(t3, 2)]) ^ (Te4_1[byte(t0, 1)]) ^ (Te4_0[byte(t1, 0)]) ^ rk[2]; STORE32H(s2, ct+8); s3 = (Te4_3[byte(t3, 3)]) ^ (Te4_2[byte(t0, 2)]) ^ (Te4_1[byte(t1, 1)]) ^ (Te4_0[byte(t2, 0)]) ^ rk[3]; STORE32H(s3, ct+12); } #ifdef LTC_CLEAN_STACK void ECB_ENC(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) { _rijndael_ecb_encrypt(pt, ct, skey); burn_stack(sizeof(unsigned long)*8 + sizeof(unsigned long*) + sizeof(int)*2); } #endif #ifndef ENCRYPT_ONLY /** Decrypts a block of text with AES @param ct The input ciphertext (16 bytes) @param pt The output plaintext (16 bytes) @param skey The key as scheduled */ #ifdef LTC_CLEAN_STACK static void _rijndael_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) #else void ECB_DEC(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) #endif { ulong32 s0, s1, s2, s3, t0, t1, t2, t3, *rk; int Nr, r; LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LTC_ARGCHK(skey != NULL); Nr = skey->rijndael.Nr; rk = skey->rijndael.dK; /* * map byte array block to cipher state * and add initial round key: */ LOAD32H(s0, ct ); s0 ^= rk[0]; LOAD32H(s1, ct + 4); s1 ^= rk[1]; LOAD32H(s2, ct + 8); s2 ^= rk[2]; LOAD32H(s3, ct + 12); s3 ^= rk[3]; #ifdef LTC_SMALL_CODE for (r = 0; ; r++) { rk += 4; t0 = Td0(byte(s0, 3)) ^ Td1(byte(s3, 2)) ^ Td2(byte(s2, 1)) ^ Td3(byte(s1, 0)) ^ rk[0]; t1 = Td0(byte(s1, 3)) ^ Td1(byte(s0, 2)) ^ Td2(byte(s3, 1)) ^ Td3(byte(s2, 0)) ^ rk[1]; t2 = Td0(byte(s2, 3)) ^ Td1(byte(s1, 2)) ^ Td2(byte(s0, 1)) ^ Td3(byte(s3, 0)) ^ rk[2]; t3 = Td0(byte(s3, 3)) ^ Td1(byte(s2, 2)) ^ Td2(byte(s1, 1)) ^ Td3(byte(s0, 0)) ^ rk[3]; if (r == Nr-2) { break; } s0 = t0; s1 = t1; s2 = t2; s3 = t3; } rk += 4; #else /* * Nr - 1 full rounds: */ r = Nr >> 1; for (;;) { t0 = Td0(byte(s0, 3)) ^ Td1(byte(s3, 2)) ^ Td2(byte(s2, 1)) ^ Td3(byte(s1, 0)) ^ rk[4]; t1 = Td0(byte(s1, 3)) ^ Td1(byte(s0, 2)) ^ Td2(byte(s3, 1)) ^ Td3(byte(s2, 0)) ^ rk[5]; t2 = Td0(byte(s2, 3)) ^ Td1(byte(s1, 2)) ^ Td2(byte(s0, 1)) ^ Td3(byte(s3, 0)) ^ rk[6]; t3 = Td0(byte(s3, 3)) ^ Td1(byte(s2, 2)) ^ Td2(byte(s1, 1)) ^ Td3(byte(s0, 0)) ^ rk[7]; rk += 8; if (--r == 0) { break; } s0 = Td0(byte(t0, 3)) ^ Td1(byte(t3, 2)) ^ Td2(byte(t2, 1)) ^ Td3(byte(t1, 0)) ^ rk[0]; s1 = Td0(byte(t1, 3)) ^ Td1(byte(t0, 2)) ^ Td2(byte(t3, 1)) ^ Td3(byte(t2, 0)) ^ rk[1]; s2 = Td0(byte(t2, 3)) ^ Td1(byte(t1, 2)) ^ Td2(byte(t0, 1)) ^ Td3(byte(t3, 0)) ^ rk[2]; s3 = Td0(byte(t3, 3)) ^ Td1(byte(t2, 2)) ^ Td2(byte(t1, 1)) ^ Td3(byte(t0, 0)) ^ rk[3]; } #endif /* * apply last round and * map cipher state to byte array block: */ s0 = (Td4[byte(t0, 3)] & 0xff000000) ^ (Td4[byte(t3, 2)] & 0x00ff0000) ^ (Td4[byte(t2, 1)] & 0x0000ff00) ^ (Td4[byte(t1, 0)] & 0x000000ff) ^ rk[0]; STORE32H(s0, pt); s1 = (Td4[byte(t1, 3)] & 0xff000000) ^ (Td4[byte(t0, 2)] & 0x00ff0000) ^ (Td4[byte(t3, 1)] & 0x0000ff00) ^ (Td4[byte(t2, 0)] & 0x000000ff) ^ rk[1]; STORE32H(s1, pt+4); s2 = (Td4[byte(t2, 3)] & 0xff000000) ^ (Td4[byte(t1, 2)] & 0x00ff0000) ^ (Td4[byte(t0, 1)] & 0x0000ff00) ^ (Td4[byte(t3, 0)] & 0x000000ff) ^ rk[2]; STORE32H(s2, pt+8); s3 = (Td4[byte(t3, 3)] & 0xff000000) ^ (Td4[byte(t2, 2)] & 0x00ff0000) ^ (Td4[byte(t1, 1)] & 0x0000ff00) ^ (Td4[byte(t0, 0)] & 0x000000ff) ^ rk[3]; STORE32H(s3, pt+12); } #ifdef LTC_CLEAN_STACK void ECB_DEC(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) { _rijndael_ecb_decrypt(ct, pt, skey); burn_stack(sizeof(unsigned long)*8 + sizeof(unsigned long*) + sizeof(int)*2); } #endif /** Performs a self-test of the AES block cipher @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled */ int ECB_TEST(void) { #ifndef LTC_TEST return CRYPT_NOP; #else int err; static const struct { int keylen; unsigned char key[32], pt[16], ct[16]; } tests[] = { { 16, { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f }, { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff }, { 0x69, 0xc4, 0xe0, 0xd8, 0x6a, 0x7b, 0x04, 0x30, 0xd8, 0xcd, 0xb7, 0x80, 0x70, 0xb4, 0xc5, 0x5a } }, { 24, { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 }, { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff }, { 0xdd, 0xa9, 0x7c, 0xa4, 0x86, 0x4c, 0xdf, 0xe0, 0x6e, 0xaf, 0x70, 0xa0, 0xec, 0x0d, 0x71, 0x91 } }, { 32, { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f }, { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff }, { 0x8e, 0xa2, 0xb7, 0xca, 0x51, 0x67, 0x45, 0xbf, 0xea, 0xfc, 0x49, 0x90, 0x4b, 0x49, 0x60, 0x89 } } }; symmetric_key key; unsigned char tmp[2][16]; int i, y; for (i = 0; i < (int)(sizeof(tests)/sizeof(tests[0])); i++) { zeromem(&key, sizeof(key)); if ((err = rijndael_setup(tests[i].key, tests[i].keylen, 0, &key)) != CRYPT_OK) { return err; } rijndael_ecb_encrypt(tests[i].pt, tmp[0], &key); rijndael_ecb_decrypt(tmp[0], tmp[1], &key); if (memcmp(tmp[0], tests[i].ct, 16) || memcmp(tmp[1], tests[i].pt, 16)) { #if 0 printf("\n\nTest %d failed\n", i); if (memcmp(tmp[0], tests[i].ct, 16)) { printf("CT: "); for (i = 0; i < 16; i++) { printf("%02x ", tmp[0][i]); } printf("\n"); } else { printf("PT: "); for (i = 0; i < 16; i++) { printf("%02x ", tmp[1][i]); } printf("\n"); } #endif return CRYPT_FAIL_TESTVECTOR; } /* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */ for (y = 0; y < 16; y++) tmp[0][y] = 0; for (y = 0; y < 1000; y++) rijndael_ecb_encrypt(tmp[0], tmp[0], &key); for (y = 0; y < 1000; y++) rijndael_ecb_decrypt(tmp[0], tmp[0], &key); for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR; } return CRYPT_OK; #endif } #endif /* ENCRYPT_ONLY */ /** Terminate the context @param skey The scheduled key */ void ECB_DONE(symmetric_key *skey) { } /** Gets suitable key size @param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable. @return CRYPT_OK if the input key size is acceptable. */ int ECB_KS(int *keysize) { LTC_ARGCHK(keysize != NULL); if (*keysize < 16) return CRYPT_INVALID_KEYSIZE; if (*keysize < 24) { *keysize = 16; return CRYPT_OK; } else if (*keysize < 32) { *keysize = 24; return CRYPT_OK; } else { *keysize = 32; return CRYPT_OK; } } #endif /* $Source: /cvs/libtom/libtomcrypt/src/ciphers/aes/aes.c,v $ */ /* $Revision: 1.8 $ */ /* $Date: 2005/05/05 14:35:58 $ */