1 files changed, 21 insertions, 0 deletions
diff --git a/arcfour.c b/arcfour.c
index 87f4959f..795a2d77 100644
--- a/arcfour.c
+++ b/arcfour.c
@@ -69,3 +69,24 @@ arcfour128_set_key(struct arcfour_ctx *ctx, const uint8_t *key)
 {
   arcfour_set_key (ctx, ARCFOUR128_KEY_SIZE, key);
 }
+
+void
+arcfour_crypt(struct arcfour_ctx *ctx,
+	      size_t length, uint8_t *dst,
+	      const uint8_t *src)
+{
+  register uint8_t i, j;
+  register int si, sj;
+
+  i = ctx->i; j = ctx->j;
+  while(length--)
+    {
+      i++; i &= 0xff;
+      si = ctx->S[i];
+      j += si; j &= 0xff;
+      sj = ctx->S[i] = ctx->S[j];
+      ctx->S[j] = si;
+      *dst++ = *src++ ^ ctx->S[ (si + sj) & 0xff ];
+    }
+  ctx->i = i; ctx->j = j;
+}