Add a helper function for converting an M of N script address to a transaction

src/libckpool.c

@@ -1503,7 +1503,7 @@ static const int b58tobin_tbl[] = {
 	47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57
 };
 
-/* b58bin should always be at least 25 bytes long and already checked to be
+/* b58bin should always be at least 21 bytes long and already checked to be
  * valid. */
 void b58tobin(char *b58bin, const char *b58)
 {
@@ -1619,9 +1619,8 @@ char *http_base64(const char *src)
 
 void address_to_pubkeytxn(char *pkh, const char *addr)
 {
-	char b58bin[25];
+	char b58bin[25] = {};
 
-	memset(b58bin, 0, 25);
 	b58tobin(b58bin, addr);
 	pkh[0] = 0x76;
 	pkh[1] = 0xa9;
@@ -1631,6 +1630,16 @@ void address_to_pubkeytxn(char *pkh, const char *addr)
 	pkh[24] = 0xac;
 }
 
+void address_to_scripttxn(char *pkh, const char *addr)
+{
+	char b58bin[23] = {};
+
+	b58tobin(b58bin, addr);
+	pkh[0] = 0xa9;
+	memcpy(&pkh[1], &b58bin[1], 20);
+	pkh[22] = 0x87;
+}
+
 /*  For encoding nHeight into coinbase, return how many bytes were used */
 int ser_number(uchar *s, int32_t val)
 {

src/libckpool.h

@@ -537,6 +537,7 @@ int safecmp(const char *a, const char *b);
 bool cmdmatch(const char *buf, const char *cmd);
 
 void address_to_pubkeytxn(char *pkh, const char *addr);
+void address_to_scripttxn(char *pkh, const char *addr);
 int ser_number(uchar *s, int32_t val);
 int get_sernumber(uchar *s);
 bool fulltest(const uchar *hash, const uchar *target);