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authorDamien Miller <djm@mindrot.org>2010-08-31 22:41:14 +1000
committerDamien Miller <djm@mindrot.org>2010-08-31 22:41:14 +1000
commiteb8b60e320cdade9f4c07e2abacfb92c52e01348 (patch)
tree4e5bc25790566402e5b7ae00cefd2c57e867ef09 /PROTOCOL
parentda108ece6843f1268aa36d7c8ed0030dc53acd15 (diff)
- djm@cvs.openbsd.org 2010/08/31 11:54:45
[PROTOCOL PROTOCOL.agent PROTOCOL.certkeys auth2-jpake.c authfd.c] [authfile.c buffer.h dns.c kex.c kex.h key.c key.h monitor.c] [monitor_wrap.c myproposal.h packet.c packet.h pathnames.h readconf.c] [ssh-add.1 ssh-add.c ssh-agent.1 ssh-agent.c ssh-keygen.1 ssh-keygen.c] [ssh-keyscan.1 ssh-keyscan.c ssh-keysign.8 ssh.1 ssh.c ssh2.h] [ssh_config.5 sshconnect.c sshconnect2.c sshd.8 sshd.c sshd_config.5] [uuencode.c uuencode.h bufec.c kexecdh.c kexecdhc.c kexecdhs.c ssh-ecdsa.c] Implement Elliptic Curve Cryptography modes for key exchange (ECDH) and host/user keys (ECDSA) as specified by RFC5656. ECDH and ECDSA offer better performance than plain DH and DSA at the same equivalent symmetric key length, as well as much shorter keys. Only the mandatory sections of RFC5656 are implemented, specifically the three REQUIRED curves nistp256, nistp384 and nistp521 and only ECDH and ECDSA. Point compression (optional in RFC5656 is NOT implemented). Certificate host and user keys using the new ECDSA key types are supported. Note that this code has not been tested for interoperability and may be subject to change. feedback and ok markus@
Diffstat (limited to 'PROTOCOL')
-rw-r--r--PROTOCOL45
1 files changed, 31 insertions, 14 deletions
diff --git a/PROTOCOL b/PROTOCOL
index 5fc31ead..5d2a7118 100644
--- a/PROTOCOL
+++ b/PROTOCOL
@@ -12,7 +12,9 @@ are individually implemented as extensions described below.
The protocol used by OpenSSH's ssh-agent is described in the file
PROTOCOL.agent
-1. transport: Protocol 2 MAC algorithm "umac-64@openssh.com"
+1. Transport protocol changes
+
+1.1. transport: Protocol 2 MAC algorithm "umac-64@openssh.com"
This is a new transport-layer MAC method using the UMAC algorithm
(rfc4418). This method is identical to the "umac-64" method documented
@@ -20,7 +22,7 @@ in:
http://www.openssh.com/txt/draft-miller-secsh-umac-01.txt
-2. transport: Protocol 2 compression algorithm "zlib@openssh.com"
+1.2. transport: Protocol 2 compression algorithm "zlib@openssh.com"
This transport-layer compression method uses the zlib compression
algorithm (identical to the "zlib" method in rfc4253), but delays the
@@ -31,14 +33,27 @@ The method is documented in:
http://www.openssh.com/txt/draft-miller-secsh-compression-delayed-00.txt
-3. transport: New public key algorithms "ssh-rsa-cert-v00@openssh.com" and
- "ssh-dsa-cert-v00@openssh.com"
+1.3. transport: New public key algorithms "ssh-rsa-cert-v00@openssh.com",
+ "ssh-dsa-cert-v00@openssh.com",
+ "ecdsa-sha2-nistp256-cert-v01@openssh.com",
+ "ecdsa-sha2-nistp384-cert-v01@openssh.com" and
+ "ecdsa-sha2-nistp521-cert-v01@openssh.com"
-OpenSSH introduces two new public key algorithms to support certificate
+OpenSSH introduces new public key algorithms to support certificate
authentication for users and hostkeys. These methods are documented in
the file PROTOCOL.certkeys
-4. connection: Channel write close extension "eow@openssh.com"
+1.4. transport: Elliptic Curve cryptography
+
+OpenSSH supports ECC key exchange and public key authentication as
+specified in RFC5656. Only the ecdsa-sha2-nistp256, ecdsa-sha2-nistp384
+and ecdsa-sha2-nistp521 curves over GF(p) are supported. Elliptic
+curve points encoded using point compression are NOT accepted or
+generated.
+
+2. Connection protocol changes
+
+2.1. connection: Channel write close extension "eow@openssh.com"
The SSH connection protocol (rfc4254) provides the SSH_MSG_CHANNEL_EOF
message to allow an endpoint to signal its peer that it will send no
@@ -77,8 +92,8 @@ message is only sent to OpenSSH peers (identified by banner).
Other SSH implementations may be whitelisted to receive this message
upon request.
-5. connection: disallow additional sessions extension
- "no-more-sessions@openssh.com"
+2.2. connection: disallow additional sessions extension
+ "no-more-sessions@openssh.com"
Most SSH connections will only ever request a single session, but a
attacker may abuse a running ssh client to surreptitiously open
@@ -105,7 +120,7 @@ of this message, the no-more-sessions request is only sent to OpenSSH
servers (identified by banner). Other SSH implementations may be
whitelisted to receive this message upon request.
-6. connection: Tunnel forward extension "tun@openssh.com"
+2.3. connection: Tunnel forward extension "tun@openssh.com"
OpenSSH supports layer 2 and layer 3 tunnelling via the "tun@openssh.com"
channel type. This channel type supports forwarding of network packets
@@ -166,7 +181,9 @@ The contents of the "data" field for layer 2 packets is:
The "frame" field contains an IEEE 802.3 Ethernet frame, including
header.
-7. sftp: Reversal of arguments to SSH_FXP_SYMLINK
+3. SFTP protocol changes
+
+3.1. sftp: Reversal of arguments to SSH_FXP_SYMLINK
When OpenSSH's sftp-server was implemented, the order of the arguments
to the SSH_FXP_SYMLINK method was inadvertently reversed. Unfortunately,
@@ -179,7 +196,7 @@ SSH_FXP_SYMLINK as follows:
string targetpath
string linkpath
-8. sftp: Server extension announcement in SSH_FXP_VERSION
+3.2. sftp: Server extension announcement in SSH_FXP_VERSION
OpenSSH's sftp-server lists the extensions it supports using the
standard extension announcement mechanism in the SSH_FXP_VERSION server
@@ -200,7 +217,7 @@ ever changed in an incompatible way. The server MAY advertise the same
extension with multiple versions (though this is unlikely). Clients MUST
check the version number before attempting to use the extension.
-9. sftp: Extension request "posix-rename@openssh.com"
+3.3. sftp: Extension request "posix-rename@openssh.com"
This operation provides a rename operation with POSIX semantics, which
are different to those provided by the standard SSH_FXP_RENAME in
@@ -217,7 +234,7 @@ rename(oldpath, newpath) and will respond with a SSH_FXP_STATUS message.
This extension is advertised in the SSH_FXP_VERSION hello with version
"1".
-10. sftp: Extension requests "statvfs@openssh.com" and
+3.4. sftp: Extension requests "statvfs@openssh.com" and
"fstatvfs@openssh.com"
These requests correspond to the statvfs and fstatvfs POSIX system
@@ -258,4 +275,4 @@ The values of the f_flag bitmask are as follows:
Both the "statvfs@openssh.com" and "fstatvfs@openssh.com" extensions are
advertised in the SSH_FXP_VERSION hello with version "2".
-$OpenBSD: PROTOCOL,v 1.15 2010/02/26 20:29:54 djm Exp $
+$OpenBSD: PROTOCOL,v 1.16 2010/08/31 11:54:45 djm Exp $