Mercurial > dropbear
view libtomcrypt/src/ciphers/rc5.c @ 1156:a8f4dade70e5
avoid getpass when not used
some systems (like android's bionic) do not provide getpass. you can
disable ENABLE_CLI_PASSWORD_AUTH & ENABLE_CLI_INTERACT_AUTH to avoid
its use (and rely on pubkey auth), but the link still fails because
the support file calls getpass. do not define this func if both of
those auth methods are not used.
author | Mike Frysinger <vapier@gentoo.org> |
---|---|
date | Wed, 21 Oct 2015 22:39:55 +0800 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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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.com */ /** @file rc5.c RC5 code by Tom St Denis */ #include "tomcrypt.h" #ifdef RC5 const struct ltc_cipher_descriptor rc5_desc = { "rc5", 2, 8, 128, 8, 12, &rc5_setup, &rc5_ecb_encrypt, &rc5_ecb_decrypt, &rc5_test, &rc5_done, &rc5_keysize, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; static const ulong32 stab[50] = { 0xb7e15163UL, 0x5618cb1cUL, 0xf45044d5UL, 0x9287be8eUL, 0x30bf3847UL, 0xcef6b200UL, 0x6d2e2bb9UL, 0x0b65a572UL, 0xa99d1f2bUL, 0x47d498e4UL, 0xe60c129dUL, 0x84438c56UL, 0x227b060fUL, 0xc0b27fc8UL, 0x5ee9f981UL, 0xfd21733aUL, 0x9b58ecf3UL, 0x399066acUL, 0xd7c7e065UL, 0x75ff5a1eUL, 0x1436d3d7UL, 0xb26e4d90UL, 0x50a5c749UL, 0xeedd4102UL, 0x8d14babbUL, 0x2b4c3474UL, 0xc983ae2dUL, 0x67bb27e6UL, 0x05f2a19fUL, 0xa42a1b58UL, 0x42619511UL, 0xe0990ecaUL, 0x7ed08883UL, 0x1d08023cUL, 0xbb3f7bf5UL, 0x5976f5aeUL, 0xf7ae6f67UL, 0x95e5e920UL, 0x341d62d9UL, 0xd254dc92UL, 0x708c564bUL, 0x0ec3d004UL, 0xacfb49bdUL, 0x4b32c376UL, 0xe96a3d2fUL, 0x87a1b6e8UL, 0x25d930a1UL, 0xc410aa5aUL, 0x62482413UL, 0x007f9dccUL }; /** Initialize the RC5 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 */ #ifdef LTC_CLEAN_STACK static int _rc5_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) #else int rc5_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) #endif { ulong32 L[64], *S, A, B, i, j, v, s, t, l; LTC_ARGCHK(skey != NULL); LTC_ARGCHK(key != NULL); /* test parameters */ if (num_rounds == 0) { num_rounds = rc5_desc.default_rounds; } if (num_rounds < 12 || num_rounds > 24) { return CRYPT_INVALID_ROUNDS; } /* key must be between 64 and 1024 bits */ if (keylen < 8 || keylen > 128) { return CRYPT_INVALID_KEYSIZE; } skey->rc5.rounds = num_rounds; S = skey->rc5.K; /* copy the key into the L array */ for (A = i = j = 0; i < (ulong32)keylen; ) { A = (A << 8) | ((ulong32)(key[i++] & 255)); if ((i & 3) == 0) { L[j++] = BSWAP(A); A = 0; } } if ((keylen & 3) != 0) { A <<= (ulong32)((8 * (4 - (keylen&3)))); L[j++] = BSWAP(A); } /* setup the S array */ t = (ulong32)(2 * (num_rounds + 1)); XMEMCPY(S, stab, t * sizeof(*S)); /* mix buffer */ s = 3 * MAX(t, j); l = j; for (A = B = i = j = v = 0; v < s; v++) { A = S[i] = ROLc(S[i] + A + B, 3); B = L[j] = ROL(L[j] + A + B, (A+B)); if (++i == t) { i = 0; } if (++j == l) { j = 0; } } return CRYPT_OK; } #ifdef LTC_CLEAN_STACK int rc5_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) { int x; x = _rc5_setup(key, keylen, num_rounds, skey); burn_stack(sizeof(ulong32) * 122 + sizeof(int)); return x; } #endif /** Encrypts a block of text with RC5 @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 */ #ifdef LTC_CLEAN_STACK static int _rc5_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) #else int rc5_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) #endif { ulong32 A, B, *K; int r; LTC_ARGCHK(skey != NULL); LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LOAD32L(A, &pt[0]); LOAD32L(B, &pt[4]); A += skey->rc5.K[0]; B += skey->rc5.K[1]; K = skey->rc5.K + 2; if ((skey->rc5.rounds & 1) == 0) { for (r = 0; r < skey->rc5.rounds; r += 2) { A = ROL(A ^ B, B) + K[0]; B = ROL(B ^ A, A) + K[1]; A = ROL(A ^ B, B) + K[2]; B = ROL(B ^ A, A) + K[3]; K += 4; } } else { for (r = 0; r < skey->rc5.rounds; r++) { A = ROL(A ^ B, B) + K[0]; B = ROL(B ^ A, A) + K[1]; K += 2; } } STORE32L(A, &ct[0]); STORE32L(B, &ct[4]); return CRYPT_OK; } #ifdef LTC_CLEAN_STACK int rc5_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey) { int err = _rc5_ecb_encrypt(pt, ct, skey); burn_stack(sizeof(ulong32) * 2 + sizeof(int)); return err; } #endif /** Decrypts a block of text with RC5 @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 */ #ifdef LTC_CLEAN_STACK static int _rc5_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) #else int rc5_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) #endif { ulong32 A, B, *K; int r; LTC_ARGCHK(skey != NULL); LTC_ARGCHK(pt != NULL); LTC_ARGCHK(ct != NULL); LOAD32L(A, &ct[0]); LOAD32L(B, &ct[4]); K = skey->rc5.K + (skey->rc5.rounds << 1); if ((skey->rc5.rounds & 1) == 0) { K -= 2; for (r = skey->rc5.rounds - 1; r >= 0; r -= 2) { B = ROR(B - K[3], A) ^ A; A = ROR(A - K[2], B) ^ B; B = ROR(B - K[1], A) ^ A; A = ROR(A - K[0], B) ^ B; K -= 4; } } else { for (r = skey->rc5.rounds - 1; r >= 0; r--) { B = ROR(B - K[1], A) ^ A; A = ROR(A - K[0], B) ^ B; K -= 2; } } A -= skey->rc5.K[0]; B -= skey->rc5.K[1]; STORE32L(A, &pt[0]); STORE32L(B, &pt[4]); return CRYPT_OK; } #ifdef LTC_CLEAN_STACK int rc5_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey) { int err = _rc5_ecb_decrypt(ct, pt, skey); burn_stack(sizeof(ulong32) * 2 + sizeof(int)); return err; } #endif /** Performs a self-test of the RC5 block cipher @return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled */ int rc5_test(void) { #ifndef LTC_TEST return CRYPT_NOP; #else static const struct { unsigned char key[16], pt[8], ct[8]; } tests[] = { { { 0x91, 0x5f, 0x46, 0x19, 0xbe, 0x41, 0xb2, 0x51, 0x63, 0x55, 0xa5, 0x01, 0x10, 0xa9, 0xce, 0x91 }, { 0x21, 0xa5, 0xdb, 0xee, 0x15, 0x4b, 0x8f, 0x6d }, { 0xf7, 0xc0, 0x13, 0xac, 0x5b, 0x2b, 0x89, 0x52 } }, { { 0x78, 0x33, 0x48, 0xe7, 0x5a, 0xeb, 0x0f, 0x2f, 0xd7, 0xb1, 0x69, 0xbb, 0x8d, 0xc1, 0x67, 0x87 }, { 0xF7, 0xC0, 0x13, 0xAC, 0x5B, 0x2B, 0x89, 0x52 }, { 0x2F, 0x42, 0xB3, 0xB7, 0x03, 0x69, 0xFC, 0x92 } }, { { 0xDC, 0x49, 0xdb, 0x13, 0x75, 0xa5, 0x58, 0x4f, 0x64, 0x85, 0xb4, 0x13, 0xb5, 0xf1, 0x2b, 0xaf }, { 0x2F, 0x42, 0xB3, 0xB7, 0x03, 0x69, 0xFC, 0x92 }, { 0x65, 0xc1, 0x78, 0xb2, 0x84, 0xd1, 0x97, 0xcc } } }; unsigned char tmp[2][8]; int x, y, err; symmetric_key key; for (x = 0; x < (int)(sizeof(tests) / sizeof(tests[0])); x++) { /* setup key */ if ((err = rc5_setup(tests[x].key, 16, 12, &key)) != CRYPT_OK) { return err; } /* encrypt and decrypt */ rc5_ecb_encrypt(tests[x].pt, tmp[0], &key); rc5_ecb_decrypt(tmp[0], tmp[1], &key); /* compare */ if (XMEMCMP(tmp[0], tests[x].ct, 8) != 0 || XMEMCMP(tmp[1], tests[x].pt, 8) != 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++) rc5_ecb_encrypt(tmp[0], tmp[0], &key); for (y = 0; y < 1000; y++) rc5_ecb_decrypt(tmp[0], tmp[0], &key); for (y = 0; y < 8; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR; } return CRYPT_OK; #endif } /** Terminate the context @param skey The scheduled key */ void rc5_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 rc5_keysize(int *keysize) { LTC_ARGCHK(keysize != NULL); if (*keysize < 8) { return CRYPT_INVALID_KEYSIZE; } else if (*keysize > 128) { *keysize = 128; } return CRYPT_OK; } #endif /* $Source: /cvs/libtom/libtomcrypt/src/ciphers/rc5.c,v $ */ /* $Revision: 1.12 $ */ /* $Date: 2006/11/08 23:01:06 $ */