+++ /dev/null
-/* LibTomCrypt, modular cryptographic library -- Tom St Denis
- *
- * LibTomCrypt is a library that provides various cryptographic
- * algorithms in a highly modular and flexible manner.
- *
- * The library is free for all purposes without any express
- * guarantee it works.
- */
-
-#include "tomcrypt.h"
-
-#ifdef LTC_RC4_STREAM
-
-/**
- Initialize an RC4 context (only the key)
- @param st [out] The destination of the RC4 state
- @param key The secret key
- @param keylen The length of the secret key (8 - 256 bytes)
- @return CRYPT_OK if successful
-*/
-int rc4_stream_setup(rc4_state *st, const unsigned char *key, unsigned long keylen)
-{
- unsigned char tmp, *s;
- int x, y;
- unsigned long j;
-
- LTC_ARGCHK(st != NULL);
- LTC_ARGCHK(key != NULL);
- LTC_ARGCHK(keylen >= 5); /* 40-2048 bits */
-
- s = st->buf;
- for (x = 0; x < 256; x++) {
- s[x] = x;
- }
-
- for (j = x = y = 0; x < 256; x++) {
- y = (y + s[x] + key[j++]) & 255;
- if (j == keylen) {
- j = 0;
- }
- tmp = s[x]; s[x] = s[y]; s[y] = tmp;
- }
- st->x = 0;
- st->y = 0;
-
- return CRYPT_OK;
-}
-
-/**
- Encrypt (or decrypt) bytes of ciphertext (or plaintext) with RC4
- @param st The RC4 state
- @param in The plaintext (or ciphertext)
- @param inlen The length of the input (octets)
- @param out [out] The ciphertext (or plaintext), length inlen
- @return CRYPT_OK if successful
-*/
-int rc4_stream_crypt(rc4_state *st, const unsigned char *in, unsigned long inlen, unsigned char *out)
-{
- unsigned char x, y, *s, tmp;
-
- LTC_ARGCHK(st != NULL);
- LTC_ARGCHK(in != NULL);
- LTC_ARGCHK(out != NULL);
-
- x = st->x;
- y = st->y;
- s = st->buf;
- while (inlen--) {
- x = (x + 1) & 255;
- y = (y + s[x]) & 255;
- tmp = s[x]; s[x] = s[y]; s[y] = tmp;
- tmp = (s[x] + s[y]) & 255;
- *out++ = *in++ ^ s[tmp];
- }
- st->x = x;
- st->y = y;
- return CRYPT_OK;
-}
-
-/**
- Generate a stream of random bytes via RC4
- @param st The RC420 state
- @param out [out] The output buffer
- @param outlen The output length
- @return CRYPT_OK on success
- */
-int rc4_stream_keystream(rc4_state *st, unsigned char *out, unsigned long outlen)
-{
- if (outlen == 0) return CRYPT_OK; /* nothing to do */
- LTC_ARGCHK(out != NULL);
- XMEMSET(out, 0, outlen);
- return rc4_stream_crypt(st, out, outlen, out);
-}
-
-/**
- Terminate and clear RC4 state
- @param st The RC4 state
- @return CRYPT_OK on success
-*/
-int rc4_stream_done(rc4_state *st)
-{
- LTC_ARGCHK(st != NULL);
- XMEMSET(st, 0, sizeof(rc4_state));
- return CRYPT_OK;
-}
-
-#endif
-
-/* ref: $Format:%D$ */
-/* git commit: $Format:%H$ */
-/* commit time: $Format:%ai$ */