293 lines
8.2 KiB
C
293 lines
8.2 KiB
C
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
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*
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* LibTomCrypt is a library that provides various cryptographic
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* algorithms in a highly modular and flexible manner.
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*
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* The library is free for all purposes without any express
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* guarantee it works.
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*
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* Tom St Denis, tomstdenis@gmail.com, http://libtom.org
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*/
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/**
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@file aes.c
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Implementation of AES
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*/
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#include "tomcrypt_private.h"
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#ifdef LTC_RIJNDAEL
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#include "mbtls_aes.h"
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static __thread mbedtls_aes_context ctx_encrypt;
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#ifndef ENCRYPT_ONLY
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static __thread mbedtls_aes_context ctx_decrypt;
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#define SETUP rijndael_setup
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#define ECB_ENC rijndael_ecb_encrypt
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#define ECB_DEC rijndael_ecb_decrypt
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#define ECB_DONE rijndael_done
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#define ECB_TEST rijndael_test
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#define ECB_KS rijndael_keysize
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const struct ltc_cipher_descriptor rijndael_desc =
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{
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"rijndael",
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6,
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16, 32, 16, 10,
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SETUP, ECB_ENC, ECB_DEC, ECB_TEST, ECB_DONE, ECB_KS,
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NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
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};
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const struct ltc_cipher_descriptor aes_desc =
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{
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"aes",
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6,
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16, 32, 16, 10,
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SETUP, ECB_ENC, ECB_DEC, ECB_TEST, ECB_DONE, ECB_KS,
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NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
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};
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#else
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#define SETUP rijndael_enc_setup
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#define ECB_ENC rijndael_enc_ecb_encrypt
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#define ECB_KS rijndael_enc_keysize
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#define ECB_DONE rijndael_enc_done
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const struct ltc_cipher_descriptor rijndael_enc_desc =
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{
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"rijndael",
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6,
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16, 32, 16, 10,
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SETUP, ECB_ENC, NULL, NULL, ECB_DONE, ECB_KS,
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NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
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};
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const struct ltc_cipher_descriptor aes_enc_desc =
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{
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"aes",
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6,
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16, 32, 16, 10,
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SETUP, ECB_ENC, NULL, NULL, ECB_DONE, ECB_KS,
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NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
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};
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#endif
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/**
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Initialize the AES (Rijndael) block cipher
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@param key The symmetric key you wish to pass
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@param keylen The key length in bytes
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@param num_rounds The number of rounds desired (0 for default)
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@param skey The key in as scheduled by this function.
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@return CRYPT_OK if successful
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*/
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int SETUP(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
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{
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LTC_ARGCHK(key != NULL);
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LTC_ARGCHK(skey != NULL);
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if (keylen != 16 && keylen != 24 && keylen != 32) {
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return CRYPT_INVALID_KEYSIZE;
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}
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if (num_rounds != 0 && num_rounds != (10 + ((keylen/8)-2)*2)) {
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return CRYPT_INVALID_ROUNDS;
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}
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mbedtls_aes_init(&ctx_encrypt);
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if (mbedtls_aes_setkey_enc(&ctx_encrypt, key, keylen*8) != 0)
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return CRYPT_INVALID_KEYSIZE;
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memcpy(skey->rijndael.eK, ctx_encrypt.buf, sizeof(skey->rijndael.eK));
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#ifndef ENCRYPT_ONLY
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mbedtls_aes_init(&ctx_decrypt);
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if (mbedtls_aes_setkey_dec(&ctx_decrypt, key, keylen*8) != 0)
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return CRYPT_INVALID_KEYSIZE;
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memcpy(skey->rijndael.dK, ctx_decrypt.buf, sizeof(skey->rijndael.dK));
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#endif
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skey->rijndael.Nr = ctx_encrypt.nr;
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return CRYPT_OK;
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}
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/**
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Encrypts a block of text with AES
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@param pt The input plaintext (16 bytes)
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@param ct The output ciphertext (16 bytes)
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@param skey The key as scheduled
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@return CRYPT_OK if successful
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*/
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#ifdef LTC_CLEAN_STACK
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static int s_rijndael_ecb_encrypt(const unsigned char *pt, unsigned char *ct, const symmetric_key *skey)
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#else
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int ECB_ENC(const unsigned char *pt, unsigned char *ct, const symmetric_key *skey)
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#endif
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{
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LTC_ARGCHK(pt != NULL);
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LTC_ARGCHK(ct != NULL);
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LTC_ARGCHK(skey != NULL);
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ctx_encrypt.nr = skey->rijndael.Nr;
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memset(ctx_encrypt.buf, 0, sizeof(ctx_encrypt.buf));
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memcpy(ctx_encrypt.buf, skey->rijndael.eK, sizeof(skey->rijndael.eK));
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return mbedtls_aes_crypt_ecb(&ctx_encrypt, MBEDTLS_AES_ENCRYPT, pt, ct) == 0 ? CRYPT_OK : CRYPT_ERROR;
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}
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#ifdef LTC_CLEAN_STACK
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int ECB_ENC(const unsigned char *pt, unsigned char *ct, const symmetric_key *skey)
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{
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return s_rijndael_ecb_encrypt(pt, ct, skey);
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}
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#endif
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#ifndef ENCRYPT_ONLY
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/**
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Decrypts a block of text with AES
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@param ct The input ciphertext (16 bytes)
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@param pt The output plaintext (16 bytes)
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@param skey The key as scheduled
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@return CRYPT_OK if successful
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*/
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#ifdef LTC_CLEAN_STACK
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static int s_rijndael_ecb_decrypt(const unsigned char *ct, unsigned char *pt, const symmetric_key *skey)
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#else
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int ECB_DEC(const unsigned char *ct, unsigned char *pt, const symmetric_key *skey)
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#endif
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{
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LTC_ARGCHK(pt != NULL);
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LTC_ARGCHK(ct != NULL);
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LTC_ARGCHK(skey != NULL);
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ctx_decrypt.nr = skey->rijndael.Nr;
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memset(ctx_decrypt.buf, 0, sizeof(ctx_decrypt.buf));
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memcpy(ctx_decrypt.buf, skey->rijndael.dK, sizeof(skey->rijndael.dK));
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return mbedtls_aes_crypt_ecb(&ctx_decrypt, MBEDTLS_AES_DECRYPT, ct, pt) == 0 ? CRYPT_OK : CRYPT_ERROR;
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}
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#ifdef LTC_CLEAN_STACK
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int ECB_DEC(const unsigned char *ct, unsigned char *pt, const symmetric_key *skey)
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{
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return s_rijndael_ecb_decrypt(ct, pt, skey);
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}
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#endif
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/**
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Performs a self-test of the AES block cipher
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@return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
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*/
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int ECB_TEST(void)
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{
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#ifndef LTC_TEST
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return CRYPT_NOP;
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#else
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int err;
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static const struct {
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int keylen;
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unsigned char key[32], pt[16], ct[16];
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} tests[] = {
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{ 16,
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{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
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0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
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{ 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
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0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff },
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{ 0x69, 0xc4, 0xe0, 0xd8, 0x6a, 0x7b, 0x04, 0x30,
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0xd8, 0xcd, 0xb7, 0x80, 0x70, 0xb4, 0xc5, 0x5a }
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}, {
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24,
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{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
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0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
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0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 },
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{ 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
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0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff },
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{ 0xdd, 0xa9, 0x7c, 0xa4, 0x86, 0x4c, 0xdf, 0xe0,
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0x6e, 0xaf, 0x70, 0xa0, 0xec, 0x0d, 0x71, 0x91 }
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}, {
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32,
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{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
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0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
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0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
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0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f },
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{ 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
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0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff },
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{ 0x8e, 0xa2, 0xb7, 0xca, 0x51, 0x67, 0x45, 0xbf,
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0xea, 0xfc, 0x49, 0x90, 0x4b, 0x49, 0x60, 0x89 }
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}
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};
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symmetric_key key;
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unsigned char tmp[2][16];
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int i, y;
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for (i = 0; i < (int)(sizeof(tests)/sizeof(tests[0])); i++) {
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zeromem(&key, sizeof(key));
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if ((err = rijndael_setup(tests[i].key, tests[i].keylen, 0, &key)) != CRYPT_OK) {
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return err;
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}
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rijndael_ecb_encrypt(tests[i].pt, tmp[0], &key);
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rijndael_ecb_decrypt(tmp[0], tmp[1], &key);
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if (compare_testvector(tmp[0], 16, tests[i].ct, 16, "AES Encrypt", i) ||
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compare_testvector(tmp[1], 16, tests[i].pt, 16, "AES Decrypt", i)) {
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return CRYPT_FAIL_TESTVECTOR;
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}
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/* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
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for (y = 0; y < 16; y++) tmp[0][y] = 0;
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for (y = 0; y < 1000; y++) rijndael_ecb_encrypt(tmp[0], tmp[0], &key);
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for (y = 0; y < 1000; y++) rijndael_ecb_decrypt(tmp[0], tmp[0], &key);
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for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
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}
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return CRYPT_OK;
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#endif
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}
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#endif /* ENCRYPT_ONLY */
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/** Terminate the context
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@param skey The scheduled key
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*/
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void ECB_DONE(symmetric_key *skey)
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{
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mbedtls_aes_free(&ctx_encrypt);
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#ifndef ENCRYPT_ONLY
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mbedtls_aes_free(&ctx_decrypt);
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#endif
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}
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/**
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Gets suitable key size
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@param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable.
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@return CRYPT_OK if the input key size is acceptable.
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*/
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int ECB_KS(int *keysize)
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{
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LTC_ARGCHK(keysize != NULL);
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if (*keysize < 16) {
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return CRYPT_INVALID_KEYSIZE;
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}
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if (*keysize < 24) {
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*keysize = 16;
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return CRYPT_OK;
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}
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if (*keysize < 32) {
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*keysize = 24;
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return CRYPT_OK;
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}
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*keysize = 32;
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return CRYPT_OK;
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}
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#endif
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