pandemonium_engine/thirdparty/mbedtls/library/arc4.c

181 lines
3.7 KiB
C

/*
* An implementation of the ARCFOUR algorithm
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
/*
* The ARCFOUR algorithm was publicly disclosed on 94/09.
*
* http://groups.google.com/group/sci.crypt/msg/10a300c9d21afca0
*/
#include "common.h"
#if defined(MBEDTLS_ARC4_C)
#include "mbedtls/arc4.h"
#include "mbedtls/platform_util.h"
#include <string.h>
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_ARC4_ALT)
void mbedtls_arc4_init(mbedtls_arc4_context *ctx)
{
memset(ctx, 0, sizeof(mbedtls_arc4_context));
}
void mbedtls_arc4_free(mbedtls_arc4_context *ctx)
{
if (ctx == NULL) {
return;
}
mbedtls_platform_zeroize(ctx, sizeof(mbedtls_arc4_context));
}
/*
* ARC4 key schedule
*/
void mbedtls_arc4_setup(mbedtls_arc4_context *ctx, const unsigned char *key,
unsigned int keylen)
{
int i, j, a;
unsigned int k;
unsigned char *m;
ctx->x = 0;
ctx->y = 0;
m = ctx->m;
for (i = 0; i < 256; i++) {
m[i] = (unsigned char) i;
}
j = k = 0;
for (i = 0; i < 256; i++, k++) {
if (k >= keylen) {
k = 0;
}
a = m[i];
j = (j + a + key[k]) & 0xFF;
m[i] = m[j];
m[j] = (unsigned char) a;
}
}
/*
* ARC4 cipher function
*/
int mbedtls_arc4_crypt(mbedtls_arc4_context *ctx, size_t length, const unsigned char *input,
unsigned char *output)
{
int x, y, a, b;
size_t i;
unsigned char *m;
x = ctx->x;
y = ctx->y;
m = ctx->m;
for (i = 0; i < length; i++) {
x = (x + 1) & 0xFF; a = m[x];
y = (y + a) & 0xFF; b = m[y];
m[x] = (unsigned char) b;
m[y] = (unsigned char) a;
output[i] = (unsigned char)
(input[i] ^ m[(unsigned char) (a + b)]);
}
ctx->x = x;
ctx->y = y;
return 0;
}
#endif /* !MBEDTLS_ARC4_ALT */
#if defined(MBEDTLS_SELF_TEST)
/*
* ARC4 tests vectors as posted by Eric Rescorla in sep. 1994:
*
* http://groups.google.com/group/comp.security.misc/msg/10a300c9d21afca0
*/
static const unsigned char arc4_test_key[3][8] =
{
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
};
static const unsigned char arc4_test_pt[3][8] =
{
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
};
static const unsigned char arc4_test_ct[3][8] =
{
{ 0x75, 0xB7, 0x87, 0x80, 0x99, 0xE0, 0xC5, 0x96 },
{ 0x74, 0x94, 0xC2, 0xE7, 0x10, 0x4B, 0x08, 0x79 },
{ 0xDE, 0x18, 0x89, 0x41, 0xA3, 0x37, 0x5D, 0x3A }
};
/*
* Checkup routine
*/
int mbedtls_arc4_self_test(int verbose)
{
int i, ret = 0;
unsigned char ibuf[8];
unsigned char obuf[8];
mbedtls_arc4_context ctx;
mbedtls_arc4_init(&ctx);
for (i = 0; i < 3; i++) {
if (verbose != 0) {
mbedtls_printf(" ARC4 test #%d: ", i + 1);
}
memcpy(ibuf, arc4_test_pt[i], 8);
mbedtls_arc4_setup(&ctx, arc4_test_key[i], 8);
mbedtls_arc4_crypt(&ctx, 8, ibuf, obuf);
if (memcmp(obuf, arc4_test_ct[i], 8) != 0) {
if (verbose != 0) {
mbedtls_printf("failed\n");
}
ret = 1;
goto exit;
}
if (verbose != 0) {
mbedtls_printf("passed\n");
}
}
if (verbose != 0) {
mbedtls_printf("\n");
}
exit:
mbedtls_arc4_free(&ctx);
return ret;
}
#endif /* MBEDTLS_SELF_TEST */
#endif /* MBEDTLS_ARC4_C */