Patch from: https://github.com/nondeterministic/mailfilter/pull/7
Bug: https://bugs.gentoo.org/870625

From c8ce051933c29561bdc57de782d0445f1513100d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Holger=20Hoffst=C3=A4tte?= <holger@applied-asynchrony.com>
Date: Wed, 14 Sep 2022 18:49:20 +0200
Subject: [PATCH] Fix warnings about incorrect prototypes & use standard memcpy/memset
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Clang-15 rightfully complains about function definitions without proper
prototypes. Also replace handrolled memcpy/memset with standard
C library calls.

Signed-off-by: Holger Hoffstätte <holger@applied-asynchrony.com>
---
 src/md5c.c | 47 +++++++++++------------------------------------
 1 file changed, 11 insertions(+), 36 deletions(-)

diff --git a/src/md5c.c b/src/md5c.c
index 2c2c564..ae5ec8d 100644
--- a/src/md5c.c
+++ b/src/md5c.c
@@ -24,6 +24,7 @@ documentation and/or software.
  */
 
 #include "md5.h"
+#include <string.h>
 
 /* Constants for MD5Transform routine.
  */
@@ -94,8 +95,7 @@ Rotation is separate from addition to prevent recomputation.
 
 /* MD5 initialization. Begins an MD5 operation, writing a new context.
  */
-void MD5Init (context)
-MD5_CTX *context;                                        /* context */
+void MD5Init (MD5_CTX *context)
 {
   context->count[0] = context->count[1] = 0;
   /* Load magic initialization constants.
@@ -110,10 +110,7 @@ MD5_CTX *context;                                        /* context */
   operation, processing another message block, and updating the
   context.
  */
-void MD5Update (context, input, inputLen)
-MD5_CTX *context;                                        /* context */
-unsigned char *input;                                /* input block */
-unsigned int inputLen;                     /* length of input block */
+void MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
 {
   unsigned int i, index, partLen;
 
@@ -152,9 +149,7 @@ unsigned int inputLen;                     /* length of input block */
 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
   the message digest and zeroizing the context.
  */
-void MD5Final (digest, context)
-unsigned char digest[16];                         /* message digest */
-MD5_CTX *context;                                       /* context */
+void MD5Final (unsigned char digest[16], MD5_CTX *context)
 {
   unsigned char bits[8];
   unsigned int index, padLen;
@@ -180,9 +175,7 @@ MD5_CTX *context;                                       /* context */
 
 /* MD5 basic transformation. Transforms state based on block.
  */
-static void MD5Transform (state, block)
-uint32_t state[4];
-unsigned char block[64];
+static void MD5Transform (uint32_t state[4], unsigned char block[64])
 {
   uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 
@@ -272,10 +265,7 @@ unsigned char block[64];
 /* Encodes input (uint32_t) into output (unsigned char). Assumes len is
   a multiple of 4.
  */
-static void Encode (output, input, len)
-unsigned char *output;
-uint32_t *input;
-unsigned int len;
+static void Encode (unsigned char *output, uint32_t *input, unsigned int len)
 {
   unsigned int i, j;
 
@@ -290,10 +280,7 @@ unsigned int len;
 /* Decodes input (unsigned char) into output (uint32_t). Assumes len is
   a multiple of 4.
  */
-static void Decode (output, input, len)
-uint32_t *output;
-unsigned char *input;
-unsigned int len;
+static void Decode (uint32_t *output, unsigned char *input, unsigned int len)
 {
   unsigned int i, j;
 
@@ -305,26 +292,14 @@ unsigned int len;
 /* Note: Replace "for loop" with standard memcpy if possible.
  */
 
-static void MD5_memcpy (output, input, len)
-POINTER output;
-POINTER input;
-unsigned int len;
+static void MD5_memcpy (POINTER output, POINTER input, unsigned int len)
 {
-  unsigned int i;
-
-  for (i = 0; i < len; i++)
-  output[i] = input[i];
+  memcpy(output, input, len);
 }
 
 /* Note: Replace "for loop" with standard memset if possible.
  */
-static void MD5_memset (output, value, len)
-POINTER output;
-int value;
-unsigned int len;
+static void MD5_memset (POINTER output, int value, unsigned int len)
 {
-  unsigned int i;
-
-  for (i = 0; i < len; i++)
- ((char *)output)[i] = (char)value;
+  memset(output, value, len);
 }