1 files changed, 73 insertions, 0 deletions
diff --git a/src/lib-smtp/smtp-server-cmd-vrfy.c b/src/lib-smtp/smtp-server-cmd-vrfy.c
new file mode 100644
index 0000000..6eb2ae8
--- /dev/null
+++ b/src/lib-smtp/smtp-server-cmd-vrfy.c
@@ -0,0 +1,73 @@
+/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "smtp-syntax.h"
+
+#include "smtp-server-private.h"
+
+/* VRFY command */
+
+void smtp_server_cmd_vrfy(struct smtp_server_cmd_ctx *cmd,
+			  const char *params)
+{
+	struct smtp_server_connection *conn = cmd->conn;
+	struct smtp_server_command *command = cmd->cmd;
+	const struct smtp_server_callbacks *callbacks = conn->callbacks;
+	const char *param, *error;
+	int ret;
+
+	/* vrfy = "VRFY" SP String CRLF */
+	ret = smtp_string_parse(params, &param, &error);
+	if (ret < 0) {
+		smtp_server_reply(cmd, 501, "5.5.4",
+				  "Invalid string parameter: %s", error);
+		return;
+	} else if (ret == 0) {
+		smtp_server_reply(cmd, 501, "5.5.4", "Invalid parameters");
+		return;
+	}
+
+	smtp_server_command_ref(command);
+	if (callbacks != NULL && callbacks->conn_cmd_vrfy != NULL) {
+		/* specific implementation of VRFY command */
+		ret = callbacks->conn_cmd_vrfy(conn->context, cmd, param);
+		if (ret <= 0) {
+			i_assert(ret == 0 ||
+				 smtp_server_command_is_replied(command));
+			/* command is waiting for external event or it failed */
+			smtp_server_command_unref(&command);
+			return;
+		}
+	}
+
+	/* RFC 5321, Section 3.5.3:
+
+	   A server MUST NOT return a 250 code in response to a VRFY or EXPN
+	   command unless it has actually verified the address. In particular,
+	   a server MUST NOT return 250 if all it has done is to verify that the
+	   syntax given is valid. In that case, 502 (Command not implemented)
+	   or 500 (Syntax error, command unrecognized) SHOULD be returned. As
+	   stated elsewhere, implementation (in the sense of actually validating
+	   addresses and returning information) of VRFY and EXPN are strongly
+	   recommended. Hence, implementations that return 500 or 502 for VRFY
+	   are not in full compliance with this specification.
+
+	   There may be circumstances where an address appears to be valid but
+	   cannot reasonably be verified in real time, particularly when a
+	   server is acting as a mail exchanger for another server or domain.
+	   "Apparent validity", in this case, would normally involve at least
+	   syntax checking and might involve verification that any domains
+	   specified were ones to which the host expected to be able to relay
+	   mail. In these situations, reply code 252 SHOULD be returned.
+	 */
+	if (!smtp_server_command_is_replied(command))
+		smtp_server_cmd_vrfy_reply_default(cmd);
+	smtp_server_command_unref(&command);
+}
+
+void smtp_server_cmd_vrfy_reply_default(struct smtp_server_cmd_ctx *cmd)
+{
+	i_assert(cmd->cmd->reg->func == smtp_server_cmd_vrfy);
+
+	smtp_server_reply(cmd, 252, "2.3.3", "Try RCPT instead");
+}