Is it ok to make RFC822 messages that use LF and not CRLF?

Question

The RFC822/RFC2822 standard says that "Header fields are lines composed of a field name, followed by a colon (':'), followed by a field body, and terminated by CRLF".

But I see at least one RFC822 MIME parser that auto-normalizes payloads that use LF ("\n") into CRLF ("\r\n") before proceeding with parsing.

How safe is it to use an RFC822 format for serializing data that may have been hand-edited in places to use LF instead of CRLF? Would it be safe to send this data around to different programs & expect them to be able to parse it with various RFC822 parser libraries?

It would be nice to be able to hand edit some of the RFC822 representations if necessary, and inserting CRLF is a hassle in editors on *nix. — dan, Oct 01 '13 at 19:56

score 1 · Accepted Answer · answered Oct 01 '13 at 20:00

1

In the general case, not safe at all. Be conservative in what you send / generate.

Having said that, most Unix tools expect locally stored email files to use local line ending conventions. RFC5322 really only codifies the format used on the wire.

answered Oct 01 '13 at 20:00

tripleee

175,061
34
275
318

It looks like MTAs like Postfix strip the CRs before it saves email to a user account in /var/mail/file or into mbox format. – dan Oct 01 '13 at 20:04

Is it ok to make RFC822 messages that use LF and not CRLF?

1 Answers1