X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/a3bd24b5dc0e562c36f681106915cf37cfbe548f..33443e7caa26da1563402d548e0a871d53ccc23a:/common/crapto1/crypto1.c

diff --git a/common/crapto1/crypto1.c b/common/crapto1/crypto1.c
new file mode 100644
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--- /dev/null
+++ b/common/crapto1/crypto1.c
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+/*  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);
+}