Use C functions for RC4 public API.

Rather than having public API switch between C and assembly, always
use C functions as entry points, which then call an assembly
implementation (if available). This makes it significantly easier
to deal with symbol aliasing/namespaces and it also means we
benefit from vulnerability prevention provided by the C compiler.

Rename the assembly generated functions from RC4() to rc4_internal()
and RC4_set_key() to rc4_set_key_internal(). Always include rc4.c
and change it to use defines that are similar to those used in BN.

ok beck@ joshua@ tb@

1 files changed, 29 insertions, 5 deletions

diff --git a/src/lib/libcrypto/rc4/rc4.c b/src/lib/libcrypto/rc4/rc4.c
index bbf7c3ae4e..8ff8191a51 100644
--- a/src/lib/libcrypto/rc4/rc4.c
+++ b/src/lib/libcrypto/rc4/rc4.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rc4.c,v 1.8 2024/03/27 12:54:42 jsing Exp $ */
+/* $OpenBSD: rc4.c,v 1.9 2024/03/28 01:49:29 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -68,8 +68,13 @@
  * Date: Wed, 14 Sep 1994 06:35:31 GMT
  */
 
-void
-RC4(RC4_KEY *key, size_t len, const unsigned char *indata,
+#ifdef HAVE_RC4_INTERNAL
+void rc4_internal(RC4_KEY *key, size_t len, const unsigned char *indata,
+    unsigned char *outdata);
+
+#else
+static void
+rc4_internal(RC4_KEY *key, size_t len, const unsigned char *indata,
     unsigned char *outdata)
 {
         RC4_INT *d;
@@ -251,9 +256,14 @@ RC4(RC4_KEY *key, size_t len, const unsigned char *indata,
         key->x = x;
         key->y = y;
 }
+#endif
 
-void
-RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
+#ifdef HAVE_RC4_SET_KEY_INTERNAL
+void rc4_set_key_internal(RC4_KEY *key, int len, const unsigned char *data);
+
+#else
+static void
+rc4_set_key_internal(RC4_KEY *key, int len, const unsigned char *data)
 {
         RC4_INT tmp;
         int id1, id2;
@@ -281,3 +291,17 @@ RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
                 SK_LOOP(d, i + 3);
         }
 }
+#endif
+
+void
+RC4(RC4_KEY *key, size_t len, const unsigned char *indata,
+    unsigned char *outdata)
+{
+        rc4_internal(key, len, indata, outdata);
+}
+
+void
+RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
+{
+        rc4_set_key_internal(key, len, data);
+}