Bug-Debian: http://bugs.debian.org/584162
Reported-By: Christoph Biedl <debian.axhn@manchmal.in-ulm.de>
Forwarded: not-needed
Reviewed-By: Anibal Monsalve Salazar <anibal@debian.org>
Last-Update: 2014-08-15

From: "Daniel Richard G." <skunk@iSKUNK.ORG>
Subject: Re: ssmtp: Partial loss of message body, sending message to wrong recipicients
Date: Thu, 19 Jun 2014 14:44:30 -0400

Attached is a patch against the original 2.64 source that should address
this bug, and hopefully not break anything. An overview of my changes:

* Added code to standarise() to drop the trailing '\r' if the line
  originally ended with "\r\n".

* Added a check to header_parse() that effectively converts an "\r\n" in
  the input into '\n'.

* Added a conditional so that header_parse() doesn't pass the empty
  string to header_save()---a behavior I observed in testing, at the end
  of a header block with "\r\n" line endings.

* Simplified the last if(in_header) conditional in header_parse(),
  because it erroneously assumes that if in_header == True, then c could
  have some value other than EOF. (See the condition on the previous
  "while" loop, and the lack of any other way to exit said loop.)

  header_parse() will now properly grab a header if fed a message
  without a body (i.e. no "\n\n" ending the header block), although this
  code will still drop a header if there is no newline at the end.

Christoph, thank you for your excellent analysis, and the test cases. I
made use of them, and with my changes sSMTP appears to do the right
thing.

Debian patch from: https://sources.debian.net/patches/ssmtp/2.64-8/

Upstream-Status: Backport [debian]

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>

Index: ssmtp-2.64/ssmtp.c
===================================================================
--- ssmtp-2.64.orig/ssmtp.c
+++ ssmtp-2.64/ssmtp.c
@@ -375,6 +375,12 @@ bool_t standardise(char *str, bool_t *li
 	if((p = strchr(str, '\n'))) {
 		*p = (char)NULL;
 		*linestart = True;
+
+		/* If the line ended in "\r\n", then drop the '\r' too */
+		sl = strlen(str);
+		if(sl >= 1 && str[sl - 1] == '\r') {
+			str[sl - 1] = (char)NULL;
+		}
 	}
 	return(leadingdot);
 }
@@ -768,6 +774,14 @@ void header_parse(FILE *stream)
 		}
 		len++;
 
+		if(l == '\r' && c == '\n') {
+			/* Properly handle input that already has "\r\n"
+			   line endings; see https://bugs.debian.org/584162 */
+			l = (len >= 2 ? *(q - 2) : '\n');
+			q--;
+			len--;
+		}
+
 		if(l == '\n') {
 			switch(c) {
 				case ' ':
@@ -790,7 +804,9 @@ void header_parse(FILE *stream)
 						if((q = strrchr(p, '\n'))) {
 							*q = (char)NULL;
 						}
-						header_save(p);
+						if(len > 0) {
+							header_save(p);
+						}
 
 						q = p;
 						len = 0;
@@ -800,35 +816,12 @@ void header_parse(FILE *stream)
 
 		l = c;
 	}
-	if(in_header) {
-		if(l == '\n') {
-			switch(c) {
-				case ' ':
-				case '\t':
-						/* Must insert '\r' before '\n's embedded in header
-						   fields otherwise qmail won't accept our mail
-						   because a bare '\n' violates some RFC */
-						
-						*(q - 1) = '\r';	/* Replace previous \n with \r */
-						*q++ = '\n';		/* Insert \n */
-						len++;
-						
-						break;
-
-				case '\n':
-						in_header = False;
-
-				default:
-						*q = (char)NULL;
-						if((q = strrchr(p, '\n'))) {
-							*q = (char)NULL;
-						}
-						header_save(p);
-
-						q = p;
-						len = 0;
-			}
+	if(in_header && l == '\n') {
+		/* Got EOF while reading the header */
+		if((q = strrchr(p, '\n'))) {
+			*q = (char)NULL;
 		}
+		header_save(p);
 	}
 	(void)free(p);
 }
