static void do_arcfour_random(struct randomness *r, UINT32 length, UINT8 *dst) { #if ALLOCA_68K_BUG ALLOCA_START(alloca_ref); #endif CAST(arcfour_random, self, r); self->staging_count += RANDOM_POLL_FAST(self->super.poller, self->staging_area); if (self->staging_count > STAGE_THRESHOLD) { /* Pour the collected randomness into the pool */ UINT8 *buf = alloca(self->staging_area->hash_size); verbose("do_arcfour_random: Pouring staging area into pool.\n"); /* Get some data out of the pool, in order to keep any entropy * there. */ arcfour_stream(&self->pool, self->staging_area->hash_size, buf); HASH_UPDATE(self->staging_area, self->staging_area->hash_size, buf); HASH_DIGEST(self->staging_area, buf); arcfour_set_key(&self->pool, self->staging_area->hash_size, buf); self->staging_count = 0; } arcfour_stream(&self->pool, length, dst); #if ALLOCA_68K_BUG ALLOCA_FREE(alloca_ref); #endif }
int main (int argc, char *argv[]) { arcfour_context ctx; /* Test vector from Cryptlib via Libgcrypt labeled there: "from the State/Commerce Department". */ static char key_1[] = { 0x61, 0x8A, 0x63, 0xD2, 0xFB }; static char plaintext_1[] = { 0xDC, 0xEE, 0x4C, 0xF9, 0x2C }; static const char ciphertext_1[] = { 0xF1, 0x38, 0x29, 0xC9, 0xDE }; char scratch[16]; arcfour_setkey (&ctx, key_1, sizeof (key_1)); arcfour_stream (&ctx, plaintext_1, scratch, sizeof (plaintext_1)); if (memcmp (scratch, ciphertext_1, sizeof (ciphertext_1))) { size_t i; printf ("expected:\n"); for (i = 0; i < 5; i++) printf ("%02x ", scratch[i] & 0xFF); printf ("\ncomputed:\n"); for (i = 0; i < 5; i++) printf ("%02x ", ciphertext_1[i] & 0xFF); printf ("\n"); return 1; } /* decrypt */ arcfour_setkey (&ctx, key_1, sizeof (key_1)); arcfour_stream (&ctx, scratch, scratch, sizeof (plaintext_1)); if (memcmp (scratch, plaintext_1, sizeof (plaintext_1))) { size_t i; printf ("expected:\n"); for (i = 0; i < 5; i++) printf ("%02x ", plaintext_1[i] & 0xFF); printf ("\ncomputed:\n"); for (i = 0; i < 5; i++) printf ("%02x ", scratch[i] & 0xFF); printf ("\n"); return 1; } return 0; }
static void do_arcfour_random_slow(struct randomness *r, UINT32 length, UINT8 *dst) { #if ALLOCA_68K_BUG ALLOCA_START(alloca_ref); #endif CAST(arcfour_random, self, r); unsigned count = RANDOM_POLL_SLOW(self->super.poller, self->staging_area); debug("arcfour_random: entropy estimate for initialization: %i bits.\n", count); if (count < STAGE_THRESHOLD) { const struct exception low_entropy = STATIC_EXCEPTION(EXC_RANDOMNESS_LOW_ENTROPY, "Could not get enough entropy from the environment."); EXCEPTION_RAISE(self->e, &low_entropy); } else self->super.super.quality = 1; { /* Initialize the pool. */ UINT8 *buf = alloca(self->staging_area->hash_size); verbose("do_arcfour_random_slow: Initalizing randomness pool.\n"); HASH_DIGEST(self->staging_area, buf); arcfour_set_key(&self->pool, self->staging_area->hash_size, buf); self->staging_count = 0; } self->super.super.random = do_arcfour_random; arcfour_stream(&self->pool, length, dst); #if ALLOCA_68K_BUG ALLOCA_FREE(alloca_ref); #endif }
Gc_rc gc_cipher_decrypt_inline (gc_cipher_handle handle, size_t len, char *data) { _gc_cipher_ctx *ctx = handle; switch (ctx->alg) { #ifdef GNULIB_GC_ARCTWO case GC_ARCTWO40: switch (ctx->mode) { case GC_ECB: arctwo_decrypt (&ctx->arctwoContext, data, data, len); break; case GC_CBC: for (; len >= ARCTWO_BLOCK_SIZE; len -= ARCTWO_BLOCK_SIZE, data += ARCTWO_BLOCK_SIZE) { char tmpIV[ARCTWO_BLOCK_SIZE]; size_t i; memcpy (tmpIV, data, ARCTWO_BLOCK_SIZE); arctwo_decrypt (&ctx->arctwoContext, data, data, ARCTWO_BLOCK_SIZE); for (i = 0; i < ARCTWO_BLOCK_SIZE; i++) data[i] ^= ctx->arctwoIV[i]; memcpy (ctx->arctwoIV, tmpIV, ARCTWO_BLOCK_SIZE); } break; default: return GC_INVALID_CIPHER; } break; #endif #ifdef GNULIB_GC_ARCFOUR case GC_ARCFOUR128: case GC_ARCFOUR40: arcfour_stream (&ctx->arcfourContext, data, data, len); break; #endif #ifdef GNULIB_GC_DES case GC_DES: for (; len >= 8; len -= 8, data += 8) gl_des_ecb_decrypt (&ctx->desContext, data, data); break; #endif #ifdef GNULIB_GC_RIJNDAEL case GC_AES128: case GC_AES192: case GC_AES256: { int nblocks; nblocks = rijndaelBlockDecrypt (&ctx->aesContext, &ctx->aesDecKey, data, 8 * len, data); if (nblocks < 0) return GC_INVALID_CIPHER; } break; #endif default: return GC_INVALID_CIPHER; } return GC_OK; }