mirror of
git://git.gnupg.org/gnupg.git
synced 2024-10-31 20:08:43 +01:00
0ebd23fa76
Migrated the gpg regression tests. Some changes tp the gpg code to fix bugs and for the use in testing. make distcheck works now with gpg enabled.
109 lines
4.3 KiB
Plaintext
109 lines
4.3 KiB
Plaintext
GnuPG and OpenPGP
|
|
=================
|
|
|
|
See RFC2440 for a description of OpenPGP. We have an annotated version
|
|
of this RFC online: http://www.gnupg.org/rfc2440.html
|
|
|
|
|
|
|
|
Compatibility Notes
|
|
===================
|
|
GnuPG (>=1.0.3) is in compliance with RFC2440 despite these exceptions:
|
|
|
|
* (9.2) states that IDEA SHOULD be implemented. This is not done
|
|
due to patent problems.
|
|
|
|
|
|
All MAY features are implemented with this exception:
|
|
|
|
* multi-part armored messages are not supported.
|
|
MIME (rfc2015) should be used instead.
|
|
|
|
Most of the OPTIONAL stuff is implemented.
|
|
|
|
There are a couple of options which can be used to override some
|
|
RFC requirements. This is always mentioned with the description
|
|
of that options.
|
|
|
|
A special format of partial packet length exists for v3 packets
|
|
which can be considered to be in compliance with RFC1991; this
|
|
format is only created if a special option is active.
|
|
|
|
GnuPG uses a S2K mode of 101 for GNU extensions to the secret key
|
|
protection algorithms. This number is not defined in OpenPGP, but
|
|
given the fact that this number is in a range which used at many
|
|
other places in OpenPGP for private/experimenat algorithm identifiers,
|
|
this should be not a so bad choice. The 3 bytes "GNU" are used
|
|
to identify this as a GNU extension - see the file DETAILS for a
|
|
definition of the used data formats.
|
|
|
|
|
|
|
|
Some Notes on OpenPGP / PGP Compatibility:
|
|
==========================================
|
|
|
|
* PGP 5.x does not accept V4 signatures for anything other than
|
|
key material. The GnuPG option --force-v3-sigs mimics this
|
|
behavior.
|
|
|
|
* PGP 5.x does not recognize the "five-octet" lengths in
|
|
new-format headers or in signature subpacket lengths.
|
|
|
|
* PGP 5.0 rejects an encrypted session key if the keylength
|
|
differs from the S2K symmetric algorithm. This is a bug in its
|
|
validation function.
|
|
|
|
* PGP 5.0 does not handle multiple one-pass signature headers and
|
|
trailers. Signing one will compress the one-pass signed literal
|
|
and prefix a V3 signature instead of doing a nested one-pass
|
|
signature.
|
|
|
|
* When exporting a private key, PGP 2.x generates the header
|
|
"BEGIN PGP SECRET KEY BLOCK" instead of "BEGIN PGP PRIVATE KEY
|
|
BLOCK". All previous versions ignore the implied data type, and
|
|
look directly at the packet data type.
|
|
|
|
* In a clear-signed signature, PGP 5.0 will figure out the correct
|
|
hash algorithm if there is no "Hash:" header, but it will reject
|
|
a mismatch between the header and the actual algorithm used. The
|
|
"standard" (i.e. Zimmermann/Finney/et al.) version of PGP 2.x
|
|
rejects the "Hash:" header and assumes MD5. There are a number
|
|
of enhanced variants of PGP 2.6.x that have been modified for
|
|
SHA-1 signatures.
|
|
|
|
* PGP 5.0 can read an RSA key in V4 format, but can only recognize
|
|
it with a V3 keyid, and can properly use only a V3 format RSA
|
|
key.
|
|
|
|
* Neither PGP 5.x nor PGP 6.0 recognize ElGamal Encrypt and Sign
|
|
keys. They only handle ElGamal Encrypt-only keys.
|
|
|
|
|
|
Parts of this document are taken from:
|
|
======================================
|
|
|
|
OpenPGP Message Format
|
|
draft-ietf-openpgp-formats-07.txt
|
|
|
|
|
|
Copyright 1998 by The Internet Society. All Rights Reserved.
|
|
|
|
This document and translations of it may be copied and furnished to
|
|
others, and derivative works that comment on or otherwise explain it
|
|
or assist in its implementation may be prepared, copied, published
|
|
and distributed, in whole or in part, without restriction of any
|
|
kind, provided that the above copyright notice and this paragraph
|
|
are included on all such copies and derivative works. However, this
|
|
document itself may not be modified in any way, such as by removing
|
|
the copyright notice or references to the Internet Society or other
|
|
Internet organizations, except as needed for the purpose of
|
|
developing Internet standards in which case the procedures for
|
|
copyrights defined in the Internet Standards process must be
|
|
followed, or as required to translate it into languages other than
|
|
English.
|
|
|
|
The limited permissions granted above are perpetual and will not be
|
|
revoked by the Internet Society or its successors or assigns.
|
|
|
|
|