/src/libtomcrypt/src/ciphers/xtea.c

Source (jump to first uncovered line)
/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */

/**
  @file xtea.c
  Implementation of eXtended TEA, Tom St Denis
*/
#include "tomcrypt_private.h"

#ifdef LTC_XTEA

const struct ltc_cipher_descriptor xtea_desc =
{
    "xtea",
    1,
    16, 16, 8, 32,
    &xtea_setup,
    &xtea_ecb_encrypt,
    &xtea_ecb_decrypt,
    &xtea_test,
    &xtea_done,
    &xtea_keysize,
    NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
};

int xtea_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
{
   ulong32 x, sum, K[4];

   LTC_ARGCHK(key != NULL);
   LTC_ARGCHK(skey != NULL);

   /* check arguments */
   if (keylen != 16) {
      return CRYPT_INVALID_KEYSIZE;
   }

   if (num_rounds != 0 && num_rounds != 32) {
      return CRYPT_INVALID_ROUNDS;
   }

   /* load key */
   LOAD32H(K[0], key+0);
   LOAD32H(K[1], key+4);
   LOAD32H(K[2], key+8);
   LOAD32H(K[3], key+12);

   for (x = sum = 0; x < 32; x++) {
       skey->xtea.A[x] = (sum + K[sum&3]) & 0xFFFFFFFFUL;
       sum = (sum + 0x9E3779B9UL) & 0xFFFFFFFFUL;
       skey->xtea.B[x] = (sum + K[(sum>>11)&3]) & 0xFFFFFFFFUL;
   }

#ifdef LTC_CLEAN_STACK
   zeromem(&K, sizeof(K));
#endif

   return CRYPT_OK;
}

/**
  Encrypts a block of text with LTC_XTEA
  @param pt The input plaintext (8 bytes)
  @param ct The output ciphertext (8 bytes)
  @param skey The key as scheduled
  @return CRYPT_OK if successful
*/
int xtea_ecb_encrypt(const unsigned char *pt, unsigned char *ct, const symmetric_key *skey)
{
   ulong32 y, z;
   int r;

   LTC_ARGCHK(pt   != NULL);
   LTC_ARGCHK(ct   != NULL);
   LTC_ARGCHK(skey != NULL);

   LOAD32H(y, &pt[0]);
   LOAD32H(z, &pt[4]);
   for (r = 0; r < 32; r += 4) {
       y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r])) & 0xFFFFFFFFUL;
       z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r])) & 0xFFFFFFFFUL;

       y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+1])) & 0xFFFFFFFFUL;
       z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+1])) & 0xFFFFFFFFUL;

       y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+2])) & 0xFFFFFFFFUL;
       z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+2])) & 0xFFFFFFFFUL;

       y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+3])) & 0xFFFFFFFFUL;
       z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+3])) & 0xFFFFFFFFUL;
   }
   STORE32H(y, &ct[0]);
   STORE32H(z, &ct[4]);
   return CRYPT_OK;
}

/**
  Decrypts a block of text with LTC_XTEA
  @param ct The input ciphertext (8 bytes)
  @param pt The output plaintext (8 bytes)
  @param skey The key as scheduled
  @return CRYPT_OK if successful
*/
int xtea_ecb_decrypt(const unsigned char *ct, unsigned char *pt, const symmetric_key *skey)
{
   ulong32 y, z;
   int r;

   LTC_ARGCHK(pt   != NULL);
   LTC_ARGCHK(ct   != NULL);
   LTC_ARGCHK(skey != NULL);

   LOAD32H(y, &ct[0]);
   LOAD32H(z, &ct[4]);
   for (r = 31; r >= 0; r -= 4) {
       z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r])) & 0xFFFFFFFFUL;
       y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r])) & 0xFFFFFFFFUL;

       z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-1])) & 0xFFFFFFFFUL;
       y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-1])) & 0xFFFFFFFFUL;

       z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-2])) & 0xFFFFFFFFUL;
       y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-2])) & 0xFFFFFFFFUL;

       z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-3])) & 0xFFFFFFFFUL;
       y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-3])) & 0xFFFFFFFFUL;
   }
   STORE32H(y, &pt[0]);
   STORE32H(z, &pt[4]);
   return CRYPT_OK;
}

/**
  Performs a self-test of the LTC_XTEA block cipher
  @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
*/
int xtea_test(void)
{
 #ifndef LTC_TEST
    return CRYPT_NOP;
 #else
    static const struct {
        unsigned char key[16], pt[8], ct[8];
    } tests[] = {
       {
         { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
         { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
         { 0xde, 0xe9, 0xd4, 0xd8, 0xf7, 0x13, 0x1e, 0xd9 }
       }, {
         { 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02,
           0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04 },
         { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
         { 0xa5, 0x97, 0xab, 0x41, 0x76, 0x01, 0x4d, 0x72 }
       }, {
         { 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04,
           0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x06 },
         { 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02 },
         { 0xb1, 0xfd, 0x5d, 0xa9, 0xcc, 0x6d, 0xc9, 0xdc }
       }, {
         { 0x78, 0x69, 0x5a, 0x4b, 0x3c, 0x2d, 0x1e, 0x0f,
           0xf0, 0xe1, 0xd2, 0xc3, 0xb4, 0xa5, 0x96, 0x87 },
         { 0xf0, 0xe1, 0xd2, 0xc3, 0xb4, 0xa5, 0x96, 0x87 },
         { 0x70, 0x4b, 0x31, 0x34, 0x47, 0x44, 0xdf, 0xab }
       }, {
         { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
           0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
         { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
         { 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 }
       }, {
         { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
           0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
         { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
         { 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 }
       }, {
         { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
           0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
         { 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f },
         { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
       }, {
         { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
         { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
         { 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 }
       }, {
         { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
         { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
         { 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d }
       }, {
         { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
           0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
         { 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 },
         { 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
       }
    };
   unsigned char tmp[2][8];
   symmetric_key skey;
   int i, err, y;
   for (i = 0; i < (int)(sizeof(tests)/sizeof(tests[0])); i++) {
       zeromem(&skey, sizeof(skey));
       if ((err = xtea_setup(tests[i].key, 16, 0, &skey)) != CRYPT_OK)  {
          return err;
       }
       xtea_ecb_encrypt(tests[i].pt, tmp[0], &skey);
       xtea_ecb_decrypt(tmp[0], tmp[1], &skey);

       if (compare_testvector(tmp[0], 8, tests[i].ct, 8, "XTEA Encrypt", i) != 0 ||
             compare_testvector(tmp[1], 8, tests[i].pt, 8, "XTEA Decrypt", i) != 0) {
          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 < 8; y++) tmp[0][y] = 0;
      for (y = 0; y < 1000; y++) xtea_ecb_encrypt(tmp[0], tmp[0], &skey);
      for (y = 0; y < 1000; y++) xtea_ecb_decrypt(tmp[0], tmp[0], &skey);
      for (y = 0; y < 8; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
   } /* for */

   return CRYPT_OK;
 #endif
}

/** Terminate the context
   @param skey    The scheduled key
*/
void xtea_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 xtea_keysize(int *keysize)
{
   LTC_ARGCHK(keysize != NULL);
   if (*keysize < 16) {
      return CRYPT_INVALID_KEYSIZE;
   }
   *keysize = 16;
   return CRYPT_OK;
}


#endif




Coverage Report

Created: 2024-11-21 07:03

Line	Count	Source (jump to first uncovered line)
1		/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
2		/* SPDX-License-Identifier: Unlicense */
3
4		/**
5		@file xtea.c
6		Implementation of eXtended TEA, Tom St Denis
7		*/
8		#include "tomcrypt_private.h"
9
10		#ifdef LTC_XTEA
11
12		const struct ltc_cipher_descriptor xtea_desc =
13		{
14		"xtea",
15		1,
16		16, 16, 8, 32,
17		&xtea_setup,
18		&xtea_ecb_encrypt,
19		&xtea_ecb_decrypt,
20		&xtea_test,
21		&xtea_done,
22		&xtea_keysize,
23		NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
24		};
25
26		int xtea_setup(const unsigned char key, int keylen, int num_rounds, symmetric_key skey)
27	2	{
28	2	ulong32 x, sum, K[4];
29
30	2	LTC_ARGCHK(key != NULL);
31	2	LTC_ARGCHK(skey != NULL);
32
33		/* check arguments */
34	2	if (keylen != 16) {
35	2	return CRYPT_INVALID_KEYSIZE;
36	2	}
37
38	0	if (num_rounds != 0 && num_rounds != 32) {
39	0	return CRYPT_INVALID_ROUNDS;
40	0	}
41
42		/* load key */
43	0	LOAD32H(K[0], key+0);
44	0	LOAD32H(K[1], key+4);
45	0	LOAD32H(K[2], key+8);
46	0	LOAD32H(K[3], key+12);
47
48	0	for (x = sum = 0; x < 32; x++) {
49	0	skey->xtea.A[x] = (sum + K[sum&3]) & 0xFFFFFFFFUL;
50	0	sum = (sum + 0x9E3779B9UL) & 0xFFFFFFFFUL;
51	0	skey->xtea.B[x] = (sum + K[(sum>>11)&3]) & 0xFFFFFFFFUL;
52	0	}
53
54		#ifdef LTC_CLEAN_STACK
55		zeromem(&K, sizeof(K));
56		#endif
57
58	0	return CRYPT_OK;
59	0	}
60
61		/**
62		Encrypts a block of text with LTC_XTEA
63		@param pt The input plaintext (8 bytes)
64		@param ct The output ciphertext (8 bytes)
65		@param skey The key as scheduled
66		@return CRYPT_OK if successful
67		*/
68		int xtea_ecb_encrypt(const unsigned char pt, unsigned char ct, const symmetric_key *skey)
69	0	{
70	0	ulong32 y, z;
71	0	int r;
72
73	0	LTC_ARGCHK(pt != NULL);
74	0	LTC_ARGCHK(ct != NULL);
75	0	LTC_ARGCHK(skey != NULL);
76
77	0	LOAD32H(y, &pt[0]);
78	0	LOAD32H(z, &pt[4]);
79	0	for (r = 0; r < 32; r += 4) {
80	0	y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r])) & 0xFFFFFFFFUL;
81	0	z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r])) & 0xFFFFFFFFUL;
82
83	0	y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+1])) & 0xFFFFFFFFUL;
84	0	z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+1])) & 0xFFFFFFFFUL;
85
86	0	y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+2])) & 0xFFFFFFFFUL;
87	0	z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+2])) & 0xFFFFFFFFUL;
88
89	0	y = (y + ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r+3])) & 0xFFFFFFFFUL;
90	0	z = (z + ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r+3])) & 0xFFFFFFFFUL;
91	0	}
92	0	STORE32H(y, &ct[0]);
93	0	STORE32H(z, &ct[4]);
94	0	return CRYPT_OK;
95	0	}
96
97		/**
98		Decrypts a block of text with LTC_XTEA
99		@param ct The input ciphertext (8 bytes)
100		@param pt The output plaintext (8 bytes)
101		@param skey The key as scheduled
102		@return CRYPT_OK if successful
103		*/
104		int xtea_ecb_decrypt(const unsigned char ct, unsigned char pt, const symmetric_key *skey)
105	0	{
106	0	ulong32 y, z;
107	0	int r;
108
109	0	LTC_ARGCHK(pt != NULL);
110	0	LTC_ARGCHK(ct != NULL);
111	0	LTC_ARGCHK(skey != NULL);
112
113	0	LOAD32H(y, &ct[0]);
114	0	LOAD32H(z, &ct[4]);
115	0	for (r = 31; r >= 0; r -= 4) {
116	0	z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r])) & 0xFFFFFFFFUL;
117	0	y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r])) & 0xFFFFFFFFUL;
118
119	0	z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-1])) & 0xFFFFFFFFUL;
120	0	y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-1])) & 0xFFFFFFFFUL;
121
122	0	z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-2])) & 0xFFFFFFFFUL;
123	0	y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-2])) & 0xFFFFFFFFUL;
124
125	0	z = (z - ((((y<<4)^(y>>5)) + y) ^ skey->xtea.B[r-3])) & 0xFFFFFFFFUL;
126	0	y = (y - ((((z<<4)^(z>>5)) + z) ^ skey->xtea.A[r-3])) & 0xFFFFFFFFUL;
127	0	}
128	0	STORE32H(y, &pt[0]);
129	0	STORE32H(z, &pt[4]);
130	0	return CRYPT_OK;
131	0	}
132
133		/**
134		Performs a self-test of the LTC_XTEA block cipher
135		@return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
136		*/
137		int xtea_test(void)
138	0	{
139		#ifndef LTC_TEST
140		return CRYPT_NOP;
141		#else
142	0	static const struct {
143	0	unsigned char key[16], pt[8], ct[8];
144	0	} tests[] = {
145	0	{
146	0	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
147	0	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
148	0	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
149	0	{ 0xde, 0xe9, 0xd4, 0xd8, 0xf7, 0x13, 0x1e, 0xd9 }
150	0	}, {
151	0	{ 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02,
152	0	0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04 },
153	0	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
154	0	{ 0xa5, 0x97, 0xab, 0x41, 0x76, 0x01, 0x4d, 0x72 }
155	0	}, {
156	0	{ 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04,
157	0	0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x06 },
158	0	{ 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x02 },
159	0	{ 0xb1, 0xfd, 0x5d, 0xa9, 0xcc, 0x6d, 0xc9, 0xdc }
160	0	}, {
161	0	{ 0x78, 0x69, 0x5a, 0x4b, 0x3c, 0x2d, 0x1e, 0x0f,
162	0	0xf0, 0xe1, 0xd2, 0xc3, 0xb4, 0xa5, 0x96, 0x87 },
163	0	{ 0xf0, 0xe1, 0xd2, 0xc3, 0xb4, 0xa5, 0x96, 0x87 },
164	0	{ 0x70, 0x4b, 0x31, 0x34, 0x47, 0x44, 0xdf, 0xab }
165	0	}, {
166	0	{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
167	0	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
168	0	{ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
169	0	{ 0x49, 0x7d, 0xf3, 0xd0, 0x72, 0x61, 0x2c, 0xb5 }
170	0	}, {
171	0	{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
172	0	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
173	0	{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
174	0	{ 0xe7, 0x8f, 0x2d, 0x13, 0x74, 0x43, 0x41, 0xd8 }
175	0	}, {
176	0	{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
177	0	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f },
178	0	{ 0x5a, 0x5b, 0x6e, 0x27, 0x89, 0x48, 0xd7, 0x7f },
179	0	{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
180	0	}, {
181	0	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
182	0	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
183	0	{ 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48 },
184	0	{ 0xa0, 0x39, 0x05, 0x89, 0xf8, 0xb8, 0xef, 0xa5 }
185	0	}, {
186	0	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
187	0	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
188	0	{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 },
189	0	{ 0xed, 0x23, 0x37, 0x5a, 0x82, 0x1a, 0x8c, 0x2d }
190	0	}, {
191	0	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
192	0	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
193	0	{ 0x70, 0xe1, 0x22, 0x5d, 0x6e, 0x4e, 0x76, 0x55 },
194	0	{ 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41 }
195	0	}
196	0	};
197	0	unsigned char tmp[2][8];
198	0	symmetric_key skey;
199	0	int i, err, y;
200	0	for (i = 0; i < (int)(sizeof(tests)/sizeof(tests[0])); i++) {
201	0	zeromem(&skey, sizeof(skey));
202	0	if ((err = xtea_setup(tests[i].key, 16, 0, &skey)) != CRYPT_OK) {
203	0	return err;
204	0	}
205	0	xtea_ecb_encrypt(tests[i].pt, tmp[0], &skey);
206	0	xtea_ecb_decrypt(tmp[0], tmp[1], &skey);
207
208	0	if (compare_testvector(tmp[0], 8, tests[i].ct, 8, "XTEA Encrypt", i) != 0 \|\|
209	0	compare_testvector(tmp[1], 8, tests[i].pt, 8, "XTEA Decrypt", i) != 0) {
210	0	return CRYPT_FAIL_TESTVECTOR;
211	0	}
212
213		/* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
214	0	for (y = 0; y < 8; y++) tmp[0][y] = 0;
215	0	for (y = 0; y < 1000; y++) xtea_ecb_encrypt(tmp[0], tmp[0], &skey);
216	0	for (y = 0; y < 1000; y++) xtea_ecb_decrypt(tmp[0], tmp[0], &skey);
217	0	for (y = 0; y < 8; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
218	0	} /* for */
219
220	0	return CRYPT_OK;
221	0	#endif
222	0	}
223
224		/** Terminate the context
225		@param skey The scheduled key
226		*/
227		void xtea_done(symmetric_key *skey)
228	0	{
229	0	LTC_UNUSED_PARAM(skey);
230	0	}
231
232		/**
233		Gets suitable key size
234		@param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable.
235		@return CRYPT_OK if the input key size is acceptable.
236		*/
237		int xtea_keysize(int *keysize)
238	0	{
239	0	LTC_ARGCHK(keysize != NULL);
240	0	if (*keysize < 16) {
241	0	return CRYPT_INVALID_KEYSIZE;
242	0	}
243	0	*keysize = 16;
244	0	return CRYPT_OK;
245	0	}
246
247
248		#endif
249
250
251