--- /dev/null
+/* crypto1.c
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ as published by the Free Software Foundation; either version 2
+ of the License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ MA 02110-1301, US
+
+ Copyright (C) 2008-2008 bla <blapost@gmail.com>
+*/
+#include "crapto1.h"
+#include <stdlib.h>
+
+#define SWAPENDIAN(x)\
+ (x = (x >> 8 & 0xff00ff) | (x & 0xff00ff) << 8, x = x >> 16 | x << 16)
+
+#if defined(__arm__)
+void crypto1_create(struct Crypto1State *s, uint64_t key)
+{
+#else
+struct Crypto1State * crypto1_create(uint64_t key)
+{
+ struct Crypto1State *s = malloc(sizeof(*s));
+#endif
+ int i;
+
+ for(i = 47;s && i > 0; i -= 2) {
+ s->odd = s->odd << 1 | BIT(key, (i - 1) ^ 7);
+ s->even = s->even << 1 | BIT(key, i ^ 7);
+ }
+#if defined(__arm__)
+ return;
+#else
+ return s;
+#endif
+}
+#if defined(__arm__)
+void crypto1_destroy(struct Crypto1State *state)
+{
+ state->odd = 0;
+ state->even = 0;
+}
+#else
+void crypto1_destroy(struct Crypto1State *state)
+{
+ free(state);
+}
+#endif
+void crypto1_get_lfsr(struct Crypto1State *state, uint64_t *lfsr)
+{
+ int i;
+ for(*lfsr = 0, i = 23; i >= 0; --i) {
+ *lfsr = *lfsr << 1 | BIT(state->odd, i ^ 3);
+ *lfsr = *lfsr << 1 | BIT(state->even, i ^ 3);
+ }
+}
+uint8_t crypto1_bit(struct Crypto1State *s, uint8_t in, int is_encrypted)
+{
+ uint32_t feedin;
+ uint32_t tmp;
+ uint8_t ret = filter(s->odd);
+
+ feedin = ret & !!is_encrypted;
+ feedin ^= !!in;
+ feedin ^= LF_POLY_ODD & s->odd;
+ feedin ^= LF_POLY_EVEN & s->even;
+ s->even = s->even << 1 | parity(feedin);
+
+ tmp = s->odd;
+ s->odd = s->even;
+ s->even = tmp;
+
+ return ret;
+}
+uint8_t crypto1_byte(struct Crypto1State *s, uint8_t in, int is_encrypted)
+{
+ uint8_t i, ret = 0;
+
+ for (i = 0; i < 8; ++i)
+ ret |= crypto1_bit(s, BIT(in, i), is_encrypted) << i;
+
+ return ret;
+}
+uint32_t crypto1_word(struct Crypto1State *s, uint32_t in, int is_encrypted)
+{
+ uint32_t i, ret = 0;
+
+ for (i = 0; i < 4; ++i, in <<= 8)
+ ret = ret << 8 | crypto1_byte(s, in >> 24, is_encrypted);
+
+ return ret;
+}
+
+/* prng_successor
+ * helper used to obscure the keystream during authentication
+ */
+uint32_t prng_successor(uint32_t x, uint32_t n)
+{
+ SWAPENDIAN(x);
+ while(n--)
+ x = x >> 1 | (x >> 16 ^ x >> 18 ^ x >> 19 ^ x >> 21) << 31;
+
+ return SWAPENDIAN(x);
+}