lws_hex_from_byte_array

include/libwebsockets/lws-misc.h

@@ -309,6 +309,19 @@ lws_json_simple_strcmp(const char *buf, size_t len, const char *name, const char
 LWS_VISIBLE LWS_EXTERN int
 lws_hex_to_byte_array(const char *h, uint8_t *dest, int max);
 
+/**
+ * lws_hex_from_byte_array(): render byte array as hex char string
+ *
+ * \param src: incoming binary source array
+ * \param slen: length of src in bytes
+ * \param dest: array to fill with hex chars representing src
+ * \param len: max extent of dest
+ *
+ * This converts binary data of length slen at src, into a hex string at dest
+ * of maximum length len.  Even if truncated, the result will be NUL-terminated.
+ */
+LWS_VISIBLE LWS_EXTERN void
+lws_hex_from_byte_array(const uint8_t *src, size_t slen, char *dest, size_t len);
 
 /**
  * lws_hex_random(): generate len - 1 or - 2 characters of random ascii hex

lib/core/libwebsockets.c

@@ -155,6 +155,22 @@ lws_hex_to_byte_array(const char *h, uint8_t *dest, int max)
 
 static char *hexch = "0123456789abcdef";
 
+void
+lws_hex_from_byte_array(const uint8_t *src, size_t slen, char *dest, size_t len)
+{
+	char *end = &dest[len - 1];
+
+	while (slen-- && dest != end) {
+		uint8_t b = *src++;
+		*dest++ = hexch[b >> 4];
+		if (dest == end)
+			break;
+		*dest++ = hexch[b & 0xf];
+	}
+
+	*dest = '\0';
+}
+
 int
 lws_hex_random(struct lws_context *context, char *dest, size_t len)
 {