Fix build with clang 15: get rid of the 30-year old PROTO_LIST

hack to deal with some prehistoric compilers. Switch public
API to use char *, not unsigned char *, which is kinda pointless.
Also make arguments const where appropriate.

md5.c

@@ -60,13 +60,11 @@ documentation and/or software.
 #define S43 15
 #define S44 21
 
-static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));
-static void Encode PROTO_LIST
-  ((unsigned char *, UINT4 *, unsigned int));
-static void Decode PROTO_LIST
-  ((UINT4 *, unsigned char *, unsigned int));
-static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
-static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));
+static void MD5Transform(UINT4 [4], const unsigned char [64]);
+static void Encode(unsigned char *, UINT4 *, unsigned int);
+static void Decode(UINT4 *, const unsigned char *, unsigned int);
+static void MD5_memcpy(POINTER, POINTER, unsigned int);
+static void MD5_memset(POINTER, int, unsigned int);
 
 static unsigned char PADDING[64] = {
   0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
@@ -130,7 +128,7 @@ void MD5Init (MD5_CTX *context)
    unsigned char *input - input block
    unsigned int inputLen - length of input block
  */
-void MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
+void MD5Update (MD5_CTX *context, const char *input, unsigned int inputLen)
 {
   unsigned int i, index, partLen;
 
@@ -154,7 +152,7 @@ void MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
  MD5Transform (context->state, context->buffer);
 
  for (i = partLen; i + 63 < inputLen; i += 64)
-   MD5Transform (context->state, &input[i]);
+   MD5Transform (context->state, (const unsigned char *)(&input[i]));
 
  index = 0;
   }
@@ -172,7 +170,7 @@ void MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
   unsigned char digest[16] - message digest
   MD5_CTX *context - context
  */
-void MD5Final (unsigned char digest[16], MD5_CTX *context)
+void MD5Final (char digest[16], MD5_CTX *context)
 {
   unsigned char bits[8];
   unsigned int index, padLen;
@@ -184,13 +182,13 @@ void MD5Final (unsigned char digest[16], MD5_CTX *context)
 */
   index = (unsigned int)((context->count[0] >> 3) & 0x3f);
   padLen = (index < 56) ? (56 - index) : (120 - index);
-  MD5Update (context, PADDING, padLen);
+  MD5Update (context, (const char *)PADDING, padLen);
 
   /* Append length (before padding) */
-  MD5Update (context, bits, 8);
+  MD5Update (context, (const char *)bits, 8);
 
   /* Store state in digest */
-  Encode (digest, context->state, 16);
+  Encode ((unsigned char *)digest, context->state, 16);
 
   /* Zeroize sensitive information.
 */
@@ -199,7 +197,7 @@ void MD5Final (unsigned char digest[16], MD5_CTX *context)
 
 /* MD5 basic transformation. Transforms state based on block.
  */
-static void MD5Transform (UINT4 state[4], unsigned char block[64])
+static void MD5Transform (UINT4 state[4], const unsigned char block[64])
 {
   UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 
@@ -305,7 +303,7 @@ static void Encode (unsigned char *output, UINT4 *input, unsigned int len)
 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
   a multiple of 4.
  */
-static void Decode (UINT4 *output, unsigned char *input, unsigned int len)
+static void Decode (UINT4 *output, const unsigned char *input, unsigned int len)
 {
   unsigned int i, j;
 

md5.h

@@ -42,9 +42,8 @@ typedef struct {
   unsigned char buffer[64];                         /* input buffer */
 } MD5_CTX;
 
-void MD5Init PROTO_LIST ((MD5_CTX *));
-void MD5Update PROTO_LIST
-  ((MD5_CTX *, unsigned char *, unsigned int));
-void MD5Final PROTO_LIST ((unsigned char [16], MD5_CTX *));
+void MD5Init(MD5_CTX *);
+void MD5Update(MD5_CTX *, const char *, unsigned int);
+void MD5Final(char [16], MD5_CTX *);
 
 #endif /* MD5_H */

md5global.h

@@ -10,11 +10,6 @@ The following makes PROTOTYPES default to 0 if it has not already
 #ifndef MD5GLOBAL_H
 #define MD5GLOBAL_H
 
-
-#ifndef PROTOTYPES
-#define PROTOTYPES 0
-#endif
-
 /* POINTER defines a generic pointer type */
 typedef unsigned char *POINTER;
 
@@ -24,14 +19,4 @@ typedef unsigned short int UINT2;
 /* UINT4 defines a four byte word */
 typedef unsigned int UINT4;
 
-/* PROTO_LIST is defined depending on how PROTOTYPES is defined above.
-If using PROTOTYPES, then PROTO_LIST returns the list, otherwise it
-  returns an empty list.
- */
-#if PROTOTYPES
-#define PROTO_LIST(list) list
-#else
-#define PROTO_LIST(list) ()
-#endif
-
 #endif /* MD5GLOBAL_H */

md5utils.c

@@ -46,7 +46,7 @@
 void MD5StringArray(char *dest, str src[], unsigned int size)
 {
 	MD5_CTX context;
-	unsigned char digest[16];
+	char digest[16];
 	int i, len;
 	char *tmp;
 
@@ -77,8 +77,8 @@ int MD5File(char *dest, const char *file_name)
 
 	MD5_CTX context;
 	FILE *input;
-	unsigned char buffer[32768];
-	unsigned char hash[16];
+	char buffer[32768];
+	char hash[16];
 	unsigned int counter, size;
 
 	struct stat stats;

modules/proto_smpp/smpp.c

@@ -1547,7 +1547,7 @@ static int recv_smpp_msg(smpp_header_t *header, smpp_deliver_sm_t *body,
 
 	if (body->data_coding == SMPP_CODING_UCS2) {
 		memset(sms_body,0,2*MAX_SMS_CHARACTERS);
-		body_str.len = string2hex((unsigned char *)body->short_message,
+		body_str.len = string2hex((char *)body->short_message,
 		body->sm_length,sms_body);
 
 		body_str.s = sms_body;

modules/sip_i/sip_i.c

@@ -759,7 +759,7 @@ int get_param_pval(int isup_params_idx, int subfield_idx, int byte_idx,
 		} else {	/* else print param as hex representation */
 			pv_tr_res_buf[0] = '0';
 			pv_tr_res_buf[1] = 'x';
-			string2hex(p->val, p->len, pv_tr_res_buf + 2);
+			string2hex((const char *)p->val, p->len, pv_tr_res_buf + 2);
 			res->flags = PV_VAL_STR;
 			res->rs.len = 2 * p->len + 2;
 			res->rs.s = pv_tr_res_buf;
@@ -856,7 +856,7 @@ int get_param_pval_str(int isup_params_idx, int subfield_idx,
 	/* no aliases, print whole param as hex */
 	pv_tr_res_buf[0] = '0';
 	pv_tr_res_buf[1] = 'x';
-	string2hex(p->val, p->len, pv_tr_res_buf + 2);
+	string2hex((const char *)p->val, p->len, pv_tr_res_buf + 2);
 	res->flags = PV_VAL_STR;
 	res->rs.len = 2 * p->len + 2;
 	res->rs.s = pv_tr_res_buf;

strcommon.c

@@ -138,7 +138,7 @@ int unescape_xml(char *dst, const char *src, int src_len)
 void compute_md5(char *dst, const char *src, int src_len)
 {
 	MD5_CTX context;
-	unsigned char digest[16];
+	char digest[16];
 	MD5Init (&context);
   	MD5Update (&context, src, src_len);
 	MD5Final (digest, &context);

ut.h

@@ -433,7 +433,7 @@ inline static int hexstr2int(char *c, int len, unsigned int *val)
 
 /* double output length assumed ; does NOT zero-terminate */
 inline static int string2hex(
-	/* input */ unsigned char *str, int len,
+	/* input */ const char *str, int len,
 	/* output */ char *hex )
 {
 	int orig_len;