net: tls_credentials_shell: Add credential buffer load argument

doc/connectivity/networking/api/tls_credentials_shell.rst

@@ -15,7 +15,11 @@ Buffer Credential (``buf``)
 
 Buffer data incrementally into the credential buffer so that it can be added using the :ref:`tls_credentials_shell_add_cred` command.
 
-Alternatively, clear the credential buffer.
+Alternatively:
+
+   - Clear the credential buffer.
+
+   - Load credential directly to the credential buffer, ending with ``Ctrl + c``.
 
 Usage
 -----
@@ -28,6 +32,14 @@ To append ``<DATA>`` to the credential buffer, use:
 
 Use this as many times as needed to load the full credential into the credential buffer, then use the :ref:`tls_credentials_shell_add_cred` command to store it.
 
+To load ``<DATA>`` directly to the credential buffer, use:
+
+.. code-block:: shell
+
+   cred buf load
+   <DATA>
+   Ctrl + c
+
 To clear the credential buffer, use:
 
 .. code-block:: shell

subsys/net/lib/tls_credentials/tls_credentials_shell.c

@@ -152,10 +152,9 @@ static bool cred_buf_clear(void)
 }
 
 /* Parse a (possibly incomplete) chunk into the credential buffer */
-static int cred_buf_write(char *chunk)
+static int cred_buf_write(char *chunk, size_t chunk_len)
 {
 	char *writehead = cred_buf + cred_written;
-	size_t chunk_len = strlen(chunk);
 
 	/* Verify that there is room for the incoming chunk */
 	if ((writehead + chunk_len) >= (cred_buf + sizeof(cred_buf) - 1)) {
@@ -327,7 +326,8 @@ static void shell_clear_cred_buf(const struct shell *sh)
 /* Write data into the credential buffer, with shell feedback. */
 static int shell_write_cred_buf(const struct shell *sh, char *chunk)
 {
-	int res = cred_buf_write(chunk);
+	size_t chunk_len = strlen(chunk);
+	int res = cred_buf_write(chunk, chunk_len);
 
 	/* Report results. */
 
@@ -515,6 +515,37 @@ static int tls_cred_cmd_add(const struct shell *sh, size_t argc, char *argv[])
 	return err;
 }
 
+#define ASCII_CTRL_C 0x03
+
+static void tls_cred_cmd_load_bypass(const struct shell *sh, uint8_t *data, size_t len)
+{
+	bool escape = false;
+	int res;
+
+	for (size_t i = 0; i < len; i++) {
+		if (data[i] == ASCII_CTRL_C) {
+			len = i > 1 ? i - 1 : 0;
+			escape = true;
+			break;
+		}
+	}
+
+	res = cred_buf_write(data, len);
+	if (res == -ENOMEM) {
+		shell_set_bypass(sh, NULL);
+		shell_fprintf(sh, SHELL_ERROR, "Not enough room in credential buffer for "
+					       "provided data. Increase "
+					       "CONFIG_TLS_CREDENTIALS_SHELL_CRED_BUF_SIZE.\n");
+		shell_clear_cred_buf(sh);
+		return;
+	}
+
+	if (escape) {
+		shell_set_bypass(sh, NULL);
+		shell_fprintf(sh, SHELL_NORMAL, "Stored %d bytes.\n", cred_written);
+	}
+}
+
 /* Buffers credential data into the credential buffer. */
 static int tls_cred_cmd_buf(const struct shell *sh, size_t argc, char *argv[])
 {
@@ -524,6 +555,13 @@ static int tls_cred_cmd_buf(const struct shell *sh, size_t argc, char *argv[])
 		return 0;
 	}
 
+	if (strcmp(argv[1], "load") == 0) {
+		shell_clear_cred_buf(sh);
+
+		shell_set_bypass(sh, tls_cred_cmd_load_bypass);
+		return 0;
+	}
+
 	/* Otherwise, assume provided arg is base64 and attempt to write it into the credential
 	 * buffer.
 	 */