Add a helper function for safely checking if a buffer matches a command

src/libckpool.c

@@ -1081,6 +1081,22 @@ int safecmp(const char *a, const char *b)
 	return (strcmp(a, b));
 }
 
+/* Returns whether there is a case insensitive match of buf to cmd, safely
+ * handling NULL or zero length strings. */
+bool cmdmatch(const char *buf, const char *cmd)
+{
+	int cmdlen, buflen;
+
+	if (!buf)
+		return false;
+	buflen = strlen(buf);
+	if (!buflen)
+		return false;
+	cmdlen = strlen(cmd);
+	if (buflen < cmdlen)
+		return false;
+	return !strncasecmp(buf, cmd, cmdlen);
+}
 
 static const char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 

src/libckpool.h

@@ -415,6 +415,7 @@ bool _hex2bin(void *p, const void *vhexstr, size_t len, const char *file, const
 char *http_base64(const char *src);
 void b58tobin(char *b58bin, const char *b58);
 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);
 int ser_number(uchar *s, int32_t val);