From 5c62b6eebed4e33bbbcd4b01f7aff38196673370 Mon Sep 17 00:00:00 2001
From: Stephan Bosch <stephan.bosch@dovecot.fi>
Date: Thu, 12 Apr 2018 16:13:08 +0200
Subject: [PATCH] lib-mail: message-address: Make the parser allow paths that
 omit `<' and `>'.

This is a syntax violation, but we allow it to account for a rather wide
selection of software that does not follow the standards.
---
 src/lib-mail/message-address.c      | 17 +++++++++++++----
 src/lib-mail/test-message-address.c | 11 +++++++++--
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/lib-mail/message-address.c b/src/lib-mail/message-address.c
index f7b383468d..a9456f613c 100644
--- a/src/lib-mail/message-address.c
+++ b/src/lib-mail/message-address.c
@@ -393,10 +393,19 @@ static int parse_path(struct message_address_parser_context *ctx)
 
 	if (rfc822_skip_lwsp(&ctx->parser) <= 0)
 		return -1;
-	if (*ctx->parser.data != '<')
-		return -1;
-	if ((ret=parse_angle_addr(ctx, TRUE)) < 0 ||
-	    (ret=rfc822_skip_lwsp(&ctx->parser)) < 0 ||
+	if (*ctx->parser.data != '<') {
+		/* Cope with paths that omit < and >. This is a syntax
+		   violation, but we allow it to account for a rather wide
+		   selection of software that does not follow the standards.
+		 */
+		if ((ret=parse_local_part(ctx)) > 0 &&
+		    *ctx->parser.data == '@') {
+			ret = parse_domain(ctx);
+		}
+	} else {
+		ret = parse_angle_addr(ctx, TRUE);
+	}
+	if (ret < 0 || (ret=rfc822_skip_lwsp(&ctx->parser)) < 0 ||
 	    ctx->parser.data != ctx->parser.end ||
 	    (ctx->addr.mailbox != NULL &&
 	     (ctx->addr.domain == NULL || *ctx->addr.domain == '\0')) ||
diff --git a/src/lib-mail/test-message-address.c b/src/lib-mail/test-message-address.c
index da0b0b23bf..c0adc5dc16 100644
--- a/src/lib-mail/test-message-address.c
+++ b/src/lib-mail/test-message-address.c
@@ -355,6 +355,10 @@ static void test_message_address_path(void)
 		  { NULL, NULL, NULL, "user", "domain", FALSE } },
 		{ "  <user@domain>  ", "<user@domain>",
 		  { NULL, NULL, NULL, "user", "domain", FALSE } },
+		{ "user@domain", "<user@domain>",
+		  { NULL, NULL, NULL, "user", "domain", FALSE } },
+		{ "  user@domain  ", "<user@domain>",
+		  { NULL, NULL, NULL, "user", "domain", FALSE } },
 		{ "<\"user\"@domain>", "<user@domain>",
 		  { NULL, NULL, NULL, "user", "domain", FALSE } },
 		{ "<\"user name\"@domain>", NULL,
@@ -405,8 +409,6 @@ static void test_message_address_path_invalid(void)
 		" < ",
 		">",
 		" > ",
-		"user@domain",
-		"  user@domain  ",
 		"<user@domain",
 		"  <user@domain  ",
 		"user@domain>",
@@ -414,8 +416,13 @@ static void test_message_address_path_invalid(void)
 		"<user>",
 		"<@route@route2:user>",
 		"<@domain>",
+		"@domain",
+		"  @domain  ",
 		"<user@>",
+		"user@",
+		"  user@  ",
 		"<user@domain>bladiebla",
+		"user@domain@"
 	};
 	const struct message_address *addr;
 	unsigned int i;