Keep only base/extractor.[cc|h].

base/security/rc4.c

-// Copyright 2005-2009 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// ========================================================================
-
-#include "rc4.h"
-
-#include <inttypes.h>
-
-void RC4_setKey(RC4_CTX* ctx, const uint8_t* key, int len) {
-  uint8_t* S = ctx->S;
-  int i, j;
-
-  for (i = 0; i < 256; ++i) {
-    S[i] = i;
-  }
-
-  j = 0;
-  for (i = 0; i < 256; ++i) {
-    uint8_t tmp;
-
-    j = (j + S[i] + key[i % len]) & 255;
-
-    tmp = S[i];
-    S[i] = S[j];
-    S[j] = tmp;
-  }
-
-  ctx->i = 0;
-  ctx->j = 0;
-}
-
-void RC4_crypt(RC4_CTX* ctx,
-               const uint8_t *in,
-               uint8_t* out,
-               int len) {
-  uint8_t i = ctx->i;
-  uint8_t j = ctx->j;
-  uint8_t* S = ctx->S;
-
-  int n;
-
-  for (n = 0; n < len; ++n) {
-    uint8_t tmp;
-
-    i = (i + 1) & 255;
-    j = (j + S[i]) & 255;
-
-    tmp = S[i];
-    S[i] = S[j];
-    S[j] = tmp;
-
-    if (in) {
-      if (out) {
-        out[n] = in[n] ^ S[(S[i] + S[j]) & 255];
-      }
-    } else {
-      if (out) {
-        out[n] = S[(S[i] + S[j]) & 255];
-      }
-    }
-  }
-
-  ctx->i = i;
-  ctx->j = j;
-}
-
-void RC4_discard(RC4_CTX* ctx, int len) {
-  RC4_crypt(ctx, 0, 0, len);
-}
-
-void RC4_stream(RC4_CTX* ctx, uint8_t* out, int len) {
-  RC4_crypt(ctx, 0, out, len);
-}