In ssh, when an agent fails to return a RSA-SHA2 signature when
requested and falls back to RSA-SHA1 instead, retry the signature to
ensure that the public key algorithm sent in the SSH_MSG_USERAUTH
matches the one in the signature itself.
In sshd, strictly enforce that the public key algorithm sent in the
SSH_MSG_USERAUTH message matches what appears in the signature.
Make the sshd_config PubkeyAcceptedKeyTypes and
HostbasedAcceptedKeyTypes options control accepted signature algorithms
(previously they selected supported key types). This allows these
options to ban RSA-SHA1 in favour of RSA-SHA2.
Add new signature algorithms "rsa-sha2-256-cert-v01@openssh.com" and
"rsa-sha2-512-cert-v01@openssh.com" to force use of RSA-SHA2 signatures
with certificate keys.
feedback and ok markus@
OpenBSD-Commit-ID: c6e9f6d45eed8962ad502d315d7eaef32c419dde
pass negotiated signing algorithm though to
sshkey_verify() and check that the negotiated algorithm matches the type in
the signature (only matters for RSA SHA1/SHA2 sigs). ok markus@
OpenBSD-Commit-ID: 735fb15bf4adc060d3bee9d047a4bcaaa81b1af9
remove post-SSHv1 removal dead code from rsa.c and merge
the remaining bit that it still used into ssh-rsa.c; ok markus
Upstream-ID: ac8a048d24dcd89594b0052ea5e3404b473bfa2f
Refuse RSA keys <1024 bits in length. Improve reporting
for keys that do not meet this requirement. ok markus@
Upstream-ID: b385e2a7b13b1484792ee681daaf79e1e203df6c
implement SHA2-{256,512} for RSASSA-PKCS1-v1_5 signatures
(user and host auth) based on draft-rsa-dsa-sha2-256-03.txt and
draft-ssh-ext-info-04.txt; with & ok djm@
Upstream-ID: cf82ce532b2733e5c4b34bb7b7c94835632db309
openssh_RSA_verify return type is int, so don't make it
size_t within the function itself with only negative numbers or zero assigned
to it. bz#2460
Upstream-ID: b6e794b0c7fc4f9f329509263c8668d35f83ea55
Disables and removes dependency on OpenSSL. Many features don't
work and the set of crypto options is greatly restricted. This
will only work on system with native arc4random or /dev/urandom.
Considered highly experimental for now.
[Makefile.in auth-bsdauth.c auth-chall.c auth-options.c auth-rsa.c
[auth2-none.c auth2-pubkey.c authfile.c authfile.h cipher-3des1.c
[cipher-chachapoly.c cipher-chachapoly.h cipher.c cipher.h
[digest-libc.c digest-openssl.c digest.h dns.c entropy.c hmac.h
[hostfile.c key.c key.h krl.c monitor.c packet.c rsa.c rsa.h
[ssh-add.c ssh-agent.c ssh-dss.c ssh-ecdsa.c ssh-ed25519.c
[ssh-keygen.c ssh-pkcs11-client.c ssh-pkcs11-helper.c ssh-pkcs11.c
[ssh-rsa.c sshbuf-misc.c sshbuf.h sshconnect.c sshconnect1.c
[sshconnect2.c sshd.c sshkey.c sshkey.h
[openbsd-compat/openssl-compat.c openbsd-compat/openssl-compat.h]
New key API: refactor key-related functions to be more library-like,
existing API is offered as a set of wrappers.
with and ok markus@
Thanks also to Ben Hawkes, David Tomaschik, Ivan Fratric, Matthew
Dempsky and Ron Bowes for a detailed review a few months ago.
NB. This commit also removes portable OpenSSH support for OpenSSL
<0.9.8e.
[digest.c digest.h hostfile.c kex.c kex.h kexc25519.c kexc25519c.c]
[kexc25519s.c kexdh.c kexecdh.c kexecdhc.c kexecdhs.c kexgex.c kexgexc.c]
[kexgexs.c key.c key.h roaming_client.c roaming_common.c schnorr.c]
[schnorr.h ssh-dss.c ssh-ecdsa.c ssh-rsa.c sshconnect2.c]
Introduce digest API and use it to perform all hashing operations
rather than calling OpenSSL EVP_Digest* directly. Will make it easier
to build a reduced-feature OpenSSH without OpenSSL in future;
feedback, ok markus@
[auth2-hostbased.c auth2-pubkey.c compat.c compat.h ssh-rsa.c]
[sshconnect.c sshconnect2.c sshd.c]
refuse RSA keys from old proprietary clients/servers that use the
obsolete RSA+MD5 signature scheme. it will still be possible to connect
with these clients/servers but only DSA keys will be accepted, and we'll
deprecate them entirely in a future release. ok markus@
[ssh-dss.c ssh-ecdsa.c ssh-rsa.c]
make the original RSA and DSA signing/verification code look more like
the ECDSA/Ed25519 ones: use key_type_plain() when checking the key type
rather than tediously listing all variants, use __func__ for debug/
error messages
[auth-options.c auth1.c auth2.c bufaux.c buffer.h kex.c key.c packet.c]
[packet.h ssh-dss.c ssh-rsa.c]
Add buffer_get_cstring() and related functions that verify that the
string extracted from the buffer contains no embedded \0 characters*
This prevents random (possibly malicious) crap from being appended to
strings where it would not be noticed if the string is used with
a string(3) function.
Use the new API in a few sensitive places.
* actually, we allow a single one at the end of the string for now because
we don't know how many deployed implementations get this wrong, but don't
count on this to remain indefinitely.
[ssh-rsa.c]
more timing paranoia - compare all parts of the expected decrypted
data before returning. AFAIK not exploitable in the SSH protocol.
"groovy" deraadt@
[auth-rsa.c channels.c jpake.c key.c misc.c misc.h monitor.c]
[packet.c ssh-rsa.c]
implement a timing_safe_cmp() function to compare memory without leaking
timing information by short-circuiting like memcmp() and use it for
some of the more sensitive comparisons (though nothing high-value was
readily attackable anyway); "looks ok" markus@
[PROTOCOL.certkeys auth-options.c auth-options.h auth-rsa.c]
[auth2-pubkey.c authfd.c key.c key.h myproposal.h ssh-add.c]
[ssh-agent.c ssh-dss.c ssh-keygen.1 ssh-keygen.c ssh-rsa.c]
[sshconnect.c sshconnect2.c sshd.c]
revised certificate format ssh-{dss,rsa}-cert-v01@openssh.com with the
following changes:
move the nonce field to the beginning of the certificate where it can
better protect against chosen-prefix attacks on the signature hash
Rename "constraints" field to "critical options"
Add a new non-critical "extensions" field
Add a serial number
The older format is still support for authentication and cert generation
(use "ssh-keygen -t v00 -s ca_key ..." to generate a v00 certificate)
ok markus@
- djm@cvs.openbsd.org 2010/02/26 20:29:54
[PROTOCOL PROTOCOL.agent PROTOCOL.certkeys addrmatch.c auth-options.c]
[auth-options.h auth.h auth2-pubkey.c authfd.c dns.c dns.h hostfile.c]
[hostfile.h kex.h kexdhs.c kexgexs.c key.c key.h match.h monitor.c]
[myproposal.h servconf.c servconf.h ssh-add.c ssh-agent.c ssh-dss.c]
[ssh-keygen.1 ssh-keygen.c ssh-rsa.c ssh.1 ssh.c ssh2.h sshconnect.c]
[sshconnect2.c sshd.8 sshd.c sshd_config.5]
Add support for certificate key types for users and hosts.
OpenSSH certificate key types are not X.509 certificates, but a much
simpler format that encodes a public key, identity information and
some validity constraints and signs it with a CA key. CA keys are
regular SSH keys. This certificate style avoids the attack surface
of X.509 certificates and is very easy to deploy.
Certified host keys allow automatic acceptance of new host keys
when a CA certificate is marked as sh/known_hosts.
see VERIFYING HOST KEYS in ssh(1) for details.
Certified user keys allow authentication of users when the signing
CA key is marked as trusted in authorized_keys. See "AUTHORIZED_KEYS
FILE FORMAT" in sshd(8) for details.
Certificates are minted using ssh-keygen(1), documentation is in
the "CERTIFICATES" section of that manpage.
Documentation on the format of certificates is in the file
PROTOCOL.certkeys
feedback and ok markus@
[buffer.c channels.c deattack.c misc.c scp.c session.c sftp-client.c]
[sftp-server.c ssh-agent.c ssh-rsa.c xmalloc.c xmalloc.h auth-pam.c]
[uidswap.c]
change OpenSSH's xrealloc() function from being xrealloc(p, new_size)
to xrealloc(p, new_nmemb, new_itemsize).
realloc is particularly prone to integer overflows because it is
almost always allocating "n * size" bytes, so this is a far safer
API; ok deraadt@
[channels.c monitor.c session.c session.h ssh-agent.c ssh-keygen.c]
[ssh-rsa.c ssh.c sshlogin.c]
annoying spacing fixes getting in the way of real diffs
[ssh-rsa.c]
make sure the signature has at least the expected length (don't
insist on len == hlen + oidlen, since this breaks some smartcards)
bugzilla #592; ok djm@
