1 files changed, 120 insertions, 0 deletions
diff --git a/crypto/crypto.c b/crypto/crypto.c
new file mode 100644
index 00000000..a7530356
--- /dev/null
+++ b/crypto/crypto.c
@@ -0,0 +1,120 @@
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "crypto.h"
+
+#ifdef LTC_DES
+
+static int urandom_fd;
+
+static const unsigned char odd_parity[256] = {
+		1,  1,  2,  2,  4,  4,  7,  7,  8,  8, 11, 11, 13, 13, 14, 14,
+	 16, 16, 19, 19, 21, 21, 22, 22, 25, 25, 26, 26, 28, 28, 31, 31,
+	 32, 32, 35, 35, 37, 37, 38, 38, 41, 41, 42, 42, 44, 44, 47, 47,
+	 49, 49, 50, 50, 52, 52, 55, 55, 56, 56, 59, 59, 61, 61, 62, 62,
+	 64, 64, 67, 67, 69, 69, 70, 70, 73, 73, 74, 74, 76, 76, 79, 79,
+	 81, 81, 82, 82, 84, 84, 87, 87, 88, 88, 91, 91, 93, 93, 94, 94,
+	 97, 97, 98, 98,100,100,103,103,104,104,107,107,109,109,110,110,
+	112,112,115,115,117,117,118,118,121,121,122,122,124,124,127,127,
+	128,128,131,131,133,133,134,134,137,137,138,138,140,140,143,143,
+	145,145,146,146,148,148,151,151,152,152,155,155,157,157,158,158,
+	161,161,162,162,164,164,167,167,168,168,171,171,173,173,174,174,
+	176,176,179,179,181,181,182,182,185,185,186,186,188,188,191,191,
+	193,193,194,194,196,196,199,199,200,200,203,203,205,205,206,206,
+	208,208,211,211,213,213,214,214,217,217,218,218,220,220,223,223,
+	224,224,227,227,229,229,230,230,233,233,234,234,236,236,239,239,
+	241,241,242,242,244,244,247,247,248,248,251,251,253,253,254,254
+};
+
+void DES_set_odd_parity(DES_cblock *key)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(DES_cblock); i++)
+		(*key)[i] =  odd_parity[(*key)[i]];
+}
+
+int DES_check_key_parity(const_DES_cblock *key)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(DES_cblock); i++) {
+		if ((*key)[i] != odd_parity[(*key)[i]])
+			return 0;
+	}
+
+	return 1;
+}
+
+static const DES_cblock weak_keys[] = {
+	/* weak keys */
+	{0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
+	{0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
+	{0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E},
+	{0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
+	/* semi-weak keys */
+	{0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
+	{0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
+	{0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
+	{0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
+	{0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
+	{0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
+	{0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
+	{0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
+	{0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
+	{0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
+	{0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
+	{0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}
+};
+
+int DES_is_weak_key(const_DES_cblock *key)
+{
+	int i;
+
+	for (i = 0; i < sizeof(weak_keys); i++)
+		if (!memcmp(weak_keys[i], key, sizeof(DES_cblock)))
+			return 1;
+
+	return 0;
+}
+
+int DES_set_key_checked(const_DES_cblock *key, DES_key_schedule *schedule)
+{
+	if (!DES_check_key_parity(key))
+		return -1;
+
+	if (DES_is_weak_key(key))
+		return -2;
+
+	return des_setup((const unsigned char *)key, 8, 0, schedule);
+}
+
+int DES_random_key(DES_cblock *ret)
+{
+	while (1) {
+		read(urandom_fd, ret, sizeof(DES_cblock));
+		if (DES_is_weak_key(ret))
+			continue;
+		break;
+	}
+
+	DES_set_odd_parity(ret);
+
+	return 0;
+}
+
+void DES_ecb_encrypt(const_DES_cblock *input, DES_cblock *output, DES_key_schedule *ks, int enc)
+{
+	if (enc == DES_ENCRYPT)
+		des_ecb_encrypt((const unsigned char *) input, (unsigned char *) output, ks);
+	else
+	if (enc == DES_DECRYPT)
+		des_ecb_decrypt((const unsigned char *) input, (unsigned char *) output, ks);
+	des_done(ks);
+}
+
+static void __attribute__((constructor)) init(void)
+{
+	urandom_fd = open("/dev/urandom", O_RDONLY);
+}
+#endif