view libtomcrypt/src/ciphers/aes/aes.c @ 1790:42745af83b7d

Introduce extra delay before closing unauthenticated sessions To make it harder for attackers, introduce a delay to keep an unauthenticated session open a bit longer, thus blocking a connection slot until after the delay. Without this, while there is a limit on the amount of attempts an attacker can make at the same time (MAX_UNAUTH_PER_IP), the time taken by dropbear to handle one attempt is still short and thus for each of the allowed parallel attempts many attempts can be chained one after the other. The attempt rate is then: "MAX_UNAUTH_PER_IP / <process time of one attempt>". With the delay, this rate becomes: "MAX_UNAUTH_PER_IP / UNAUTH_CLOSE_DELAY".
author Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
date Wed, 15 Feb 2017 13:53:04 +0100
parents 1ff2a1034c52
children
line wrap: on
line source

/* 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.
 */

/* 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 LTC_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, 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, 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, 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, NULL, NULL, NULL, NULL, NULL, NULL, NULL
};

#endif

#define __LTC_AES_TAB_C__
#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;
    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) {
        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) {
        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) {
        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 */
       /* coverity[dead_error_line] */
       return CRYPT_ERROR;
    }

#ifndef ENCRYPT_ONLY
    /* setup the inverse key now */
    rk   = skey->rijndael.dK;
    rrk  = skey->rijndael.eK + (28 + keylen) - 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
  @return CRYPT_OK if successful
*/
#ifdef LTC_CLEAN_STACK
static int _rijndael_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
#else
int 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);

    return CRYPT_OK;
}

#ifdef LTC_CLEAN_STACK
int ECB_ENC(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
{
   int err = _rijndael_ecb_encrypt(pt, ct, skey);
   burn_stack(sizeof(unsigned long)*8 + sizeof(unsigned long*) + sizeof(int)*2);
   return err;
}
#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
  @return CRYPT_OK if successful
*/
#ifdef LTC_CLEAN_STACK
static int _rijndael_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
#else
int 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);

    return CRYPT_OK;
}


#ifdef LTC_CLEAN_STACK
int ECB_DEC(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
{
   int err = _rijndael_ecb_decrypt(ct, pt, skey);
   burn_stack(sizeof(unsigned long)*8 + sizeof(unsigned long*) + sizeof(int)*2);
   return err;
}
#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 (compare_testvector(tmp[0], 16, tests[i].ct, 16, "AES Encrypt", i) ||
          compare_testvector(tmp[1], 16, tests[i].pt, 16, "AES Decrypt", i)) {
        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)
{
  LTC_UNUSED_PARAM(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


/* ref:         $Format:%D$ */
/* git commit:  $Format:%H$ */
/* commit time: $Format:%ai$ */