NODE 953eb36aRe: Signing ascii text
John W Noerenberg <jwn2@qualcomm.com>Wed, 23 Dec 92 09:08:22 PST
At 11:31 PM 12/22/92 -0400, Yanek Martinson wrote:
>> (e.g., email messages, etc). Is there a convention for the end of line
>> sequence that is to be used for the copy of the file that is run through
>> the hash function? If there isn't, then the file hash will depend on the
>
>Canonical Text has a CR and LF at the end of each line. This is
>documented in some RFC. All (most?) protocols used on internet such
>as smtp, finger, etc, use this format. The possible justification
>is that an extra linefeed or a carriage return is not as bad as a missing
>one.
Which RFC are you referring to? While it is true that 821, 822 (and other
RFC's which are concerned with email messages) define the end of line as a
CRLF, I'm not aware of an RFC which defines canonical text. The style of
late has been to define a line "as described in rfc822" or some such. But
I don't recall any rfc which defines canonical text spanning session-layer
(or higher) protocols. Is there one?
john noerenberg
jwn2@qualcomm.com
noerenberg.j (Applelink)
===========================================================
Do not uselessly lament your luck that is giving way, your work that has
failed, your life's plans that have all ended in despair. Like a man long
prepared, like a man of courage, bid her farewell, the Alexandria that
leaves you.
-- "The God Abandons Anthony", Constantine Peter Cavafy [1911]
===========================================================
NODE 281d2966Re: Signing ascii text
yanek@novavax.nova.edu (Yanek Martinson)Wed, 23 Dec 92 14:31:14 PST
> >Canonical Text has a CR and LF at the end of each line.
> Which RFC are you referring to?
I am not aware of any single RFC that defines this, but every RFC
that I have read, if it mentions end-of-line at all, it is defined
as, or assumed to be, a carriage return followed by a newline.
Even in cases where the native representation is different, it
is converted to this format before transmission through the net,
and then converted back. This is in some RFC-s referred to
as "internet tradition", or "NetAscii".
This is similar to the Network Byte Order. No matter what order
your machine stores bytes (little/big endian), it gets converted
to one standard format.
It is also referred to as "NVT Standard".
The only mention of a different end of line convention is in
relation to EBCDIC, which has an explicit newline <NL> character.
Here are excerpts from various RFCs that deal with, or mention,
use of CRLF at the end of lines:
Request For Comments: 1078 SRI-NIC
TCP Port Service Multiplexer (TCPMUX)
A TCP client connects to a foreign host on TCP port 1. It sends the
service name followed by a carriage-return line-feed <CRLF>.
acknowledgment, immediately followed by an optional message of
explanation, terminated with a <CRLF>. If the reply was positive,
Request for Comments: 1123 R. Braden, Editor
Requirements for Internet Hosts -- Application and Support
To allow interoperability between arbitrary Telnet clients
and servers, the Telnet protocol defined a standard
representation for a line terminator. Since the ASCII
character set includes no explicit end-of-line character,
systems have chosen various representations, e.g., CR, LF,
and the sequence CR LF. The Telnet protocol chose the CR
LF sequence as the standard for network transmission.
Request for Comments: 1184 D. Borman, Editor
Telnet Linemode Option
line should be transmitted with "CR LF" as the line terminator. When
responsible for doing all output processing. Specificly, it should
send "CR LF" when it wants the "newline" function
Request for Comments: 1204 D. Lee
Message Posting Protocol (MPP)
USER <SP> <username> <CRLF>
PASS <SP> <password> <CRLF>
DATA <CRLF>
NOOP <CRLF>
QUIT <CRLF>
354 Enter mail, end with <CRLF>.<CRLF>
Request for Comments: 1288 Center for Discrete Mathematics and
The Finger User Information Protocol
Any data transferred MUST be in ASCII format, with no parity, and
with lines ending in CRLF (ASCII 13 followed by ASCII 10).
Request for Comments: 1312 Crynwr Software
Message Send Protocol 2
New lines should be represented using the usual
Netascii CR + LF. (Following the Internet tradition,
a server should probably be prepared to accept a
message in which some other end-of-line convention is
followed, but a conforming client must use CR + LF.)
NWG/RFC# 561 AKB KP RST JEW 5-SEP-73 11:19 18516
Standardizing Network Mail Headers RFC 561 / NIC 18516
Formal Syntax:
<mailtext> ::= <header> <CRLF> <message>
<headeritem> ::= <item> <CRLF>
<message> ::= <line> <CRLF> ! <line> <CRLF> <message>
<line> ::= a string containing any of the 128 ASCII
characters except CR and LF
<word> ::= a string containing any of the 128 ASCII
characters except CR, LF, and SP
<CRLF> ::= CR LF
<SP> ::= space
RFC 821
SIMPLE MAIL TRANSFER PROTOCOL
MAIL <SP> FROM:<reverse-path> <CRLF>
RCPT <SP> TO:<forward-path> <CRLF>
DATA <CRLF>
SEND <SP> FROM:<reverse-path> <CRLF>
SOML <SP> FROM:<reverse-path> <CRLF>
SAML <SP> FROM:<reverse-path> <CRLF>
HELO <SP> <domain> <CRLF>
QUIT <CRLF>
The SMTP commands define the mail transfer or the mail system
function requested by the user. SMTP commands are character
strings terminated by <CRLF>. The command codes themselves are
alphabetic characters terminated by <SP> if parameters follow
and <CRLF> otherwise.
RFC # 822
STANDARD FOR THE FORMAT OF
ARPA INTERNET TEXT MESSAGES
A message consists of header fields and, optionally, a body.
The body is simply a sequence of lines containing ASCII charac-
ters. It is separated from the headers by a null line (i.e., a
line with nothing preceding the CRLF).
field = field-name ":" [ field-body ] CRLF
field-body = field-body-contents
[CRLF LWSP-char field-body]
Each header field may be represented on exactly one line con-
sisting of the name of the field and its body, and terminated
by a CRLF;
Request for Comments: 959 J. Reynolds
FILE TRANSFER PROTOCOL (FTP)
In accordance with the NVT standard, the <CRLF> sequence
should be used where necessary to denote the end of a line
of text. (See the discussion of file structure at the end
process will interpret appropriately. <CRLF>, in exactly
this sequence, also denotes end-of-line.
the FTP implementation should use the end-of-line sequence,
<CRLF> for ASCII, or <NL> for EBCDIC text files, as the
For the purpose of standardized transfer, the sending host will
translate its internal end of line or end of record denotation
into the representation prescribed by the transfer mode and file
structure, and the receiving host will perform the inverse
translation to its internal denotation.
End-of-line in an ASCII or EBCDIC file with no
record structure should be indicated by <CRLF> or <NL>,
respectively.
information. The data will be transferred in ASCII or
EBCDIC type over the data connection as valid pathname
strings separated by <CRLF> or <NL>. (Again the user must
Request for Comments: 977 Phil Lapsley (U.C. Berkeley)
Network News Transfer Protocol
Each command line must be terminated by a CR-LF (Carriage Return -
Line Feed) pair.
that indicates that text will follow. Text is sent as a series of
successive lines of textual matter, each terminated with CR-LF pair.
--
Yanek Martinson mthvax.cs.miami.edu!safe0!yanek uunet!medexam!yanek
this address preferred -->> yanek@novavax.nova.edu <<-- this address preferred
Phone (305) 765-6300 daytime FAX: (305) 765-6708 1321 N 65 Way/Hollywood
(305) 963-1931 evenings (305) 981-9812 Florida, 33024-5819