1 // SPDX-License-Identifier: BSD-2-Clause
2 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
3  *
4  * LibTomCrypt is a library that provides various cryptographic
5  * algorithms in a highly modular and flexible manner.
6  *
7  * The library is free for all purposes without any express
8  * guarantee it works.
9  */
10 
11 /* The implementation is based on:
12  * "Extending the Salsa20 nonce", https://cr.yp.to/snuffle/xsalsa-20081128.pdf
13  * "Salsa20 specification", http://cr.yp.to/snuffle/spec.pdf
14  * and salsa20-ref.c version 20051118
15  * Public domain from D. J. Bernstein
16  */
17 
18 #include "tomcrypt.h"
19 
20 #ifdef LTC_XSALSA20
21 
22 #if defined(LTC_SHA256) && defined(LTC_TEST)
_sha256(unsigned char * hash,const unsigned char * data,const int datalen)23 static int _sha256(unsigned char *hash, const unsigned char *data, const int datalen) {
24    hash_state md;
25    sha256_init(&md);
26    sha256_process(&md, data, datalen);
27    sha256_done(&md, hash);
28    return CRYPT_OK;
29 }
30 #endif
31 
xsalsa20_test(void)32 int xsalsa20_test(void)
33 {
34 #ifndef LTC_TEST
35    return CRYPT_NOP;
36 #else
37 
38     /***************************************************************************
39      * verify a round trip:
40      */
41     {
42         const unsigned char key[]   = {0x1b,0x27,0x55,0x64,0x73,0xe9,0x85,0xd4,0x62,0xcd,0x51,0x19,0x7a,0x9a,0x46,0xc7,0x60,0x09,0x54,0x9e,0xac,0x64,0x74,0xf2,0x06,0xc4,0xee,0x08,0x44,0xf6,0x83,0x89};
43         const unsigned char nonce[] = {0x69,0x69,0x6e,0xe9,0x55,0xb6,0x2b,0x73,0xcd,0x62,0xbd,0xa8,0x75,0xfc,0x73,0xd6,0x82,0x19,0xe0,0x03,0x6b,0x7a,0x0b,0x37};
44         const void *msg             = "Kilroy was here!";
45         unsigned char msglen = 17;                  /* includes trailing NULL */
46         int rounds = 20;
47         unsigned char ciphertext[17];
48         unsigned char msg2[17];
49         salsa20_state st;
50         int err;
51 
52         if ((err = xsalsa20_setup(&st, key, 32, nonce, 24, rounds)) != CRYPT_OK)  return err;
53         if ((err = salsa20_crypt(&st, msg, msglen, ciphertext))     != CRYPT_OK)  return err;
54         if ((err = salsa20_done(&st))                               != CRYPT_OK)  return err;
55 
56         if ((err = xsalsa20_setup(&st, key, 32, nonce, 24, rounds)) != CRYPT_OK)  return err;
57         if ((err = salsa20_crypt(&st, ciphertext, msglen, msg2))    != CRYPT_OK)  return err;
58         if ((err = salsa20_done(&st))                               != CRYPT_OK)  return err;
59 
60         if (compare_testvector(msg, msglen, msg2, msglen, "XSALSA20-TV1", 1))  return CRYPT_FAIL_TESTVECTOR;
61 
62 
63         /* round trip with two single function calls */
64         if ((err = xsalsa20_memory(key, sizeof(key), 20, nonce, sizeof(nonce), msg, msglen, ciphertext))  != CRYPT_OK)                return err;
65         if ((err = xsalsa20_memory(key, sizeof(key), 20, nonce, sizeof(nonce), ciphertext, msglen, msg2)) != CRYPT_OK)                return err;
66         if (compare_testvector(msg, msglen, msg2, msglen, "XSALSA20-TV2", 1))  return CRYPT_FAIL_TESTVECTOR;
67     }
68 
69 #ifdef LTC_SHA256
70    /***************************************************************************
71     * verify correct generation of a keystream
72     */
73    {
74        const unsigned char key[]        = {0x1b,0x27,0x55,0x64,0x73,0xe9,0x85,0xd4,0x62,0xcd,0x51,0x19,0x7a,0x9a,0x46,0xc7,0x60,0x09,0x54,0x9e,0xac,0x64,0x74,0xf2,0x06,0xc4,0xee,0x08,0x44,0xf6,0x83,0x89};
75        const unsigned char nonce[]      = {0x69,0x69,0x6e,0xe9,0x55,0xb6,0x2b,0x73,0xcd,0x62,0xbd,0xa8,0x75,0xfc,0x73,0xd6,0x82,0x19,0xe0,0x03,0x6b,0x7a,0x0b,0x37};
76        const unsigned char expecthash[] = {0x6a,0x60,0x57,0x65,0x27,0xe0,0x00,0x51,0x6d,0xb0,0xda,0x60,0x46,0x20,0xf6,0xd0,0x95,0x65,0x45,0x39,0xf4,0x86,0x83,0x43,0x64,0xdf,0xd9,0x5a,0x6f,0x3f,0xbe,0xb7};
77        int rounds = 20;
78        unsigned char keystream[91101];
79        unsigned long keystreamlen = 91101;
80        unsigned char hash[32];
81        salsa20_state st;
82        int err;
83 
84        if ((err = xsalsa20_setup(&st, key, 32, nonce, 24, rounds))   != CRYPT_OK)  return err;
85        if ((err = salsa20_keystream(&st, keystream, keystreamlen))   != CRYPT_OK)  return err;
86        if ((err = salsa20_done(&st))                                 != CRYPT_OK)  return err;
87        if ((err = _sha256(hash, keystream, keystreamlen))            != CRYPT_OK)  return err;
88        if (compare_testvector(hash, sizeof(hash), expecthash, sizeof(expecthash),   "XSALSA20-TV3", 1))  return CRYPT_FAIL_TESTVECTOR;
89    }
90 #endif
91 
92    return CRYPT_OK;
93 
94 #endif
95 }
96 
97 #endif
98 
99 /* ref:         $Format:%D$ */
100 /* git commit:  $Format:%H$ */
101 /* commit time: $Format:%ai$ */
102