Add |RC4_options| to decrepit.

I've no idea who thought that this function was a good idea in the first
place, but including it in decrepit makes supporting nmap easier.

Change-Id: I7433cda6a6ddf1cc545126edf779625e9fc70ada
Reviewed-on: https://boringssl-review.googlesource.com/7401
Reviewed-by: David Benjamin <davidben@google.com>

decrepit/CMakeLists.txt

@@ -4,6 +4,7 @@ add_subdirectory(cast)
 add_subdirectory(des)
 add_subdirectory(dsa)
 add_subdirectory(evp)
+add_subdirectory(rc4)
 add_subdirectory(rsa)
 add_subdirectory(x509)
 add_subdirectory(xts)
@@ -17,6 +18,7 @@ add_library(
   $<TARGET_OBJECTS:des_decrepit>
   $<TARGET_OBJECTS:dsa_decrepit>
   $<TARGET_OBJECTS:evp_decrepit>
+  $<TARGET_OBJECTS:rc4_decrepit>
   $<TARGET_OBJECTS:rsa_decrepit>
   $<TARGET_OBJECTS:x509>
   $<TARGET_OBJECTS:xts>

decrepit/rc4/CMakeLists.txt

@@ -0,0 +1,9 @@
+include_directories(../../include)
+
+add_library(
+  rc4_decrepit
+
+  OBJECT
+
+  rc4_decrepit.c
+)

decrepit/rc4/rc4_decrepit.c

@@ -0,0 +1,62 @@
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to.  The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *    "This product includes cryptographic software written by
+ *     Eric Young (eay@cryptsoft.com)"
+ *    The word 'cryptographic' can be left out if the rouines from the library
+ *    being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ *    the apps directory (application code) you must include an acknowledgement:
+ *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed.  i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.] */
+
+#include <openssl/rc4.h>
+
+
+const char *RC4_options(void) {
+  return "rc4(ptr,int)";
+}

include/openssl/rc4.h

@@ -83,6 +83,12 @@ OPENSSL_EXPORT void RC4(RC4_KEY *key, size_t len, const uint8_t *in,
                         uint8_t *out);
 
 
+/* Deprecated functions. */
+
+/* RC4_options returns the string "rc4(ptr,int)". */
+OPENSSL_EXPORT const char *RC4_options(void);
+
+
 #if defined(__cplusplus)
 }  /* extern C */
 #endif