+++ /dev/null
-/* 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.
- */
-#include "tomcrypt.h"
-
-/**
- @file sober128_stream.c
- Implementation of SOBER-128 by Tom St Denis.
- Based on s128fast.c reference code supplied by Greg Rose of QUALCOMM.
-*/
-
-#ifdef LTC_SOBER128
-
-#define __LTC_SOBER128TAB_C__
-#include "sober128tab.c"
-
-/* don't change these... */
-#define N 17
-#define FOLD N /* how many iterations of folding to do */
-#define INITKONST 0x6996c53a /* value of KONST to use during key loading */
-#define KEYP 15 /* where to insert key words */
-#define FOLDP 4 /* where to insert non-linear feedback */
-
-#define B(x,i) ((unsigned char)(((x) >> (8*i)) & 0xFF))
-
-static ulong32 BYTE2WORD(unsigned char *b)
-{
- ulong32 t;
- LOAD32L(t, b);
- return t;
-}
-
-static void XORWORD(ulong32 w, const unsigned char *in, unsigned char *out)
-{
- ulong32 t;
- LOAD32L(t, in);
- t ^= w;
- STORE32L(t, out);
-}
-
-/* give correct offset for the current position of the register,
- * where logically R[0] is at position "zero".
- */
-#define OFF(zero, i) (((zero)+(i)) % N)
-
-/* step the LFSR */
-/* After stepping, "zero" moves right one place */
-#define STEP(R,z) \
- R[OFF(z,0)] = R[OFF(z,15)] ^ R[OFF(z,4)] ^ (R[OFF(z,0)] << 8) ^ Multab[(R[OFF(z,0)] >> 24) & 0xFF];
-
-static void cycle(ulong32 *R)
-{
- ulong32 t;
- int i;
-
- STEP(R,0);
- t = R[0];
- for (i = 1; i < N; ++i) {
- R[i-1] = R[i];
- }
- R[N-1] = t;
-}
-
-/* Return a non-linear function of some parts of the register.
- */
-#define NLFUNC(c,z) \
-{ \
- t = c->R[OFF(z,0)] + c->R[OFF(z,16)]; \
- t ^= Sbox[(t >> 24) & 0xFF]; \
- t = RORc(t, 8); \
- t = ((t + c->R[OFF(z,1)]) ^ c->konst) + c->R[OFF(z,6)]; \
- t ^= Sbox[(t >> 24) & 0xFF]; \
- t = t + c->R[OFF(z,13)]; \
-}
-
-static ulong32 nltap(sober128_state *c)
-{
- ulong32 t;
- NLFUNC(c, 0);
- return t;
-}
-
-/* Save the current register state
- */
-static void s128_savestate(sober128_state *c)
-{
- int i;
- for (i = 0; i < N; ++i) {
- c->initR[i] = c->R[i];
- }
-}
-
-/* initialise to previously saved register state
- */
-static void s128_reloadstate(sober128_state *c)
-{
- int i;
-
- for (i = 0; i < N; ++i) {
- c->R[i] = c->initR[i];
- }
-}
-
-/* Initialise "konst"
- */
-static void s128_genkonst(sober128_state *c)
-{
- ulong32 newkonst;
-
- do {
- cycle(c->R);
- newkonst = nltap(c);
- } while ((newkonst & 0xFF000000) == 0);
- c->konst = newkonst;
-}
-
-/* Load key material into the register
- */
-#define ADDKEY(k) \
- c->R[KEYP] += (k);
-
-#define XORNL(nl) \
- c->R[FOLDP] ^= (nl);
-
-/* nonlinear diffusion of register for key */
-#define DROUND(z) STEP(c->R,z); NLFUNC(c,(z+1)); c->R[OFF((z+1),FOLDP)] ^= t;
-static void s128_diffuse(sober128_state *c)
-{
- ulong32 t;
- /* relies on FOLD == N == 17! */
- DROUND(0);
- DROUND(1);
- DROUND(2);
- DROUND(3);
- DROUND(4);
- DROUND(5);
- DROUND(6);
- DROUND(7);
- DROUND(8);
- DROUND(9);
- DROUND(10);
- DROUND(11);
- DROUND(12);
- DROUND(13);
- DROUND(14);
- DROUND(15);
- DROUND(16);
-}
-
-/**
- Initialize an Sober128 context (only the key)
- @param c [out] The destination of the Sober128 state
- @param key The secret key
- @param keylen The length of the secret key (octets)
- @return CRYPT_OK if successful
-*/
-int sober128_stream_setup(sober128_state *c, const unsigned char *key, unsigned long keylen)
-{
- ulong32 i, k;
-
- LTC_ARGCHK(c != NULL);
- LTC_ARGCHK(key != NULL);
- LTC_ARGCHK(keylen > 0);
-
- /* keylen must be multiple of 4 bytes */
- if ((keylen & 3) != 0) {
- return CRYPT_INVALID_KEYSIZE;
- }
-
- /* Register initialised to Fibonacci numbers */
- c->R[0] = 1;
- c->R[1] = 1;
- for (i = 2; i < N; ++i) {
- c->R[i] = c->R[i-1] + c->R[i-2];
- }
- c->konst = INITKONST;
-
- for (i = 0; i < keylen; i += 4) {
- k = BYTE2WORD((unsigned char *)&key[i]);
- ADDKEY(k);
- cycle(c->R);
- XORNL(nltap(c));
- }
-
- /* also fold in the length of the key */
- ADDKEY(keylen);
-
- /* now diffuse */
- s128_diffuse(c);
- s128_genkonst(c);
- s128_savestate(c);
- c->nbuf = 0;
-
- return CRYPT_OK;
-}
-
-/**
- Set IV to the Sober128 state
- @param c The Sober12820 state
- @param iv The IV data to add
- @param ivlen The length of the IV (must be 12)
- @return CRYPT_OK on success
- */
-int sober128_stream_setiv(sober128_state *c, const unsigned char *iv, unsigned long ivlen)
-{
- ulong32 i, k;
-
- LTC_ARGCHK(c != NULL);
- LTC_ARGCHK(iv != NULL);
- LTC_ARGCHK(ivlen > 0);
-
- /* ok we are adding an IV then... */
- s128_reloadstate(c);
-
- /* ivlen must be multiple of 4 bytes */
- if ((ivlen & 3) != 0) {
- return CRYPT_INVALID_KEYSIZE;
- }
-
- for (i = 0; i < ivlen; i += 4) {
- k = BYTE2WORD((unsigned char *)&iv[i]);
- ADDKEY(k);
- cycle(c->R);
- XORNL(nltap(c));
- }
-
- /* also fold in the length of the key */
- ADDKEY(ivlen);
-
- /* now diffuse */
- s128_diffuse(c);
- c->nbuf = 0;
-
- return CRYPT_OK;
-}
-
-/* XOR pseudo-random bytes into buffer
- */
-#define SROUND(z) STEP(c->R,z); NLFUNC(c,(z+1)); XORWORD(t, in+(z*4), out+(z*4));
-
-/**
- Encrypt (or decrypt) bytes of ciphertext (or plaintext) with Sober128
- @param c The Sober128 state
- @param in The plaintext (or ciphertext)
- @param inlen The length of the input (octets)
- @param out [out] The ciphertext (or plaintext), length inlen
- @return CRYPT_OK if successful
-*/
-int sober128_stream_crypt(sober128_state *c, const unsigned char *in, unsigned long inlen, unsigned char *out)
-{
- ulong32 t;
-
- if (inlen == 0) return CRYPT_OK; /* nothing to do */
- LTC_ARGCHK(out != NULL);
- LTC_ARGCHK(c != NULL);
-
- /* handle any previously buffered bytes */
- while (c->nbuf != 0 && inlen != 0) {
- *out++ = *in++ ^ (unsigned char)(c->sbuf & 0xFF);
- c->sbuf >>= 8;
- c->nbuf -= 8;
- --inlen;
- }
-
-#ifndef LTC_SMALL_CODE
- /* do lots at a time, if there's enough to do */
- while (inlen >= N*4) {
- SROUND(0);
- SROUND(1);
- SROUND(2);
- SROUND(3);
- SROUND(4);
- SROUND(5);
- SROUND(6);
- SROUND(7);
- SROUND(8);
- SROUND(9);
- SROUND(10);
- SROUND(11);
- SROUND(12);
- SROUND(13);
- SROUND(14);
- SROUND(15);
- SROUND(16);
- out += 4*N;
- in += 4*N;
- inlen -= 4*N;
- }
-#endif
-
- /* do small or odd size buffers the slow way */
- while (4 <= inlen) {
- cycle(c->R);
- t = nltap(c);
- XORWORD(t, in, out);
- out += 4;
- in += 4;
- inlen -= 4;
- }
-
- /* handle any trailing bytes */
- if (inlen != 0) {
- cycle(c->R);
- c->sbuf = nltap(c);
- c->nbuf = 32;
- while (c->nbuf != 0 && inlen != 0) {
- *out++ = *in++ ^ (unsigned char)(c->sbuf & 0xFF);
- c->sbuf >>= 8;
- c->nbuf -= 8;
- --inlen;
- }
- }
-
- return CRYPT_OK;
-}
-
-int sober128_stream_keystream(sober128_state *c, unsigned char *out, unsigned long outlen)
-{
- if (outlen == 0) return CRYPT_OK; /* nothing to do */
- LTC_ARGCHK(out != NULL);
- XMEMSET(out, 0, outlen);
- return sober128_stream_crypt(c, out, outlen, out);
-}
-
-/**
- Terminate and clear Sober128 state
- @param c The Sober128 state
- @return CRYPT_OK on success
-*/
-int sober128_stream_done(sober128_state *c)
-{
- LTC_ARGCHK(c != NULL);
- XMEMSET(c, 0, sizeof(sober128_state));
- return CRYPT_OK;
-}
-
-#endif
-
-/* ref: $Format:%D$ */
-/* git commit: $Format:%H$ */
-/* commit time: $Format:%ai$ */
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