cbor: introduce cbor_serialize_byte_stringl

sys/cbor/cbor.c

@@ -404,8 +404,9 @@ static size_t decode_bytes(const cbor_stream_t *s, size_t offset, char *out, siz
 }
 
 /* A zero copy version of decode_bytes.
-   Will not null termiante input, but tell you the size of what you read.
+   Will not null termiante input, but will tell you the size of what you read.
-   Great for reading byte strings which could contain nulls inside
+   Great for reading byte strings which could contain nulls inside of unknown size
+   without forced copies.
 */
 static size_t decode_bytes_no_copy(const cbor_stream_t *s, size_t offset, unsigned char **out, size_t *length)
 {
@@ -640,6 +641,11 @@ size_t cbor_serialize_byte_string(cbor_stream_t *stream, const char *val)
     return encode_bytes(CBOR_BYTES, stream, val, strlen(val));
 }
 
+size_t cbor_serialize_byte_stringl(cbor_stream_t *stream, const char *val, size_t length)
+{
+    return encode_bytes(CBOR_BYTES, stream, val, length);
+}
+
 size_t cbor_deserialize_unicode_string(const cbor_stream_t *stream, size_t offset, char *val,
                                        size_t length)
 {

sys/include/cbor.h

@@ -365,6 +365,16 @@ size_t cbor_deserialize_double(const cbor_stream_t *stream, size_t offset,
  */
 size_t cbor_serialize_byte_string(cbor_stream_t *stream, const char *val);
 
+/**
+ * @brief Serializes an arbitrary byte string
+ *
+ * @param[out] stream   The destination stream for serializing the byte stream
+ * @param[in] val       The arbitrary byte string which may include null bytes
+ * @param[in] length    The size of the byte string in bytes
+ *
+ * @return Number of bytes written to stream @p stream
+ */
+size_t cbor_serialize_byte_stringl(cbor_stream_t *stream, const char *val, size_t length);
 
 /**
  * @brief Deserialize bytes from @p stream to @p val