OpenSSH 8.1 was released on 2019-10-09. It is available from the mirrors listed at https://www.openssh.com/. OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support. Once again, we would like to thank the OpenSSH community for their continued support of the project, especially those who contributed code or patches, reported bugs, tested snapshots or donated to the project. More information on donations may be found at: http://www.openssh.com/donations.html Security ======== * ssh(1), sshd(8), ssh-add(1), ssh-keygen(1): an exploitable integer overflow bug was found in the private key parsing code for the XMSS key type. This key type is still experimental and support for it is not compiled by default. No user-facing autoconf option exists in portable OpenSSH to enable it. This bug was found by Adam Zabrocki and reported via SecuriTeam's SSD program. * ssh(1), sshd(8), ssh-agent(1): add protection for private keys at rest in RAM against speculation and memory side-channel attacks like Spectre, Meltdown and Rambleed. This release encrypts private keys when they are not in use with a symmetric key that is derived from a relatively large "prekey" consisting of random data (currently 16KB). Potentially-incompatible changes ================================ This release includes a number of changes that may affect existing configurations: * ssh-keygen(1): when acting as a CA and signing certificates with an RSA key, default to using the rsa-sha2-512 signature algorithm. Certificates signed by RSA keys will therefore be incompatible with OpenSSH versions prior to 7.2 unless the default is overridden (using "ssh-keygen -t ssh-rsa -s ..."). Changes since OpenSSH 8.0 ========================= This release is focused on bug-fixing. New Features ------------ * ssh(1): Allow %n to be expanded in ProxyCommand strings * ssh(1), sshd(8): Allow prepending a list of algorithms to the default set by starting the list with the '^' character, E.g. "HostKeyAlgorithms ^ssh-ed25519" * ssh-keygen(1): add an experimental lightweight signature and verification ability. Signatures may be made using regular ssh keys held on disk or stored in a ssh-agent and verified against an authorized_keys-like list of allowed keys. Signatures embed a namespace that prevents confusion and attacks between different usage domains (e.g. files vs email). * ssh-keygen(1): print key comment when extracting public key from a private key. bz#3052 * ssh-keygen(1): accept the verbose flag when searching for host keys in known hosts (i.e. "ssh-keygen -vF host") to print the matching host's random-art signature too. bz#3003 * All: support PKCS8 as an optional format for storage of private keys to disk. The OpenSSH native key format remains the default, but PKCS8 is a superior format to PEM if interoperability with non-OpenSSH software is required, as it may use a less insecure key derivation function than PEM's. Bugfixes -------- * ssh(1): if a PKCS#11 token returns no keys then try to login and refetch them. Based on patch from Jakub Jelen; bz#2430 * ssh(1): produce a useful error message if the user's shell is set incorrectly during "match exec" processing. bz#2791 * sftp(1): allow the maximum uint32 value for the argument passed to -b which allows better error messages from later validation. bz#3050 * ssh(1): avoid pledge sandbox violations in some combinations of remote forwarding, connection multiplexing and ControlMaster. * ssh-keyscan(1): include SHA2-variant RSA key algorithms in KEX proposal; allows ssh-keyscan to harvest keys from servers that disable old SHA1 ssh-rsa. bz#3029 * sftp(1): print explicit "not modified" message if a file was requested for resumed download but was considered already complete. bz#2978 * sftp(1): fix a typo and make move right to the closest end of a word just like moves left to the closest beginning of a word. * sshd(8): cap the number of permitopen/permitlisten directives allowed to appear on a single authorized_keys line. * All: fix a number of memory leaks (one-off or on exit paths). * Regression tests: a number of fixes and improvements, including fixes to the interop tests, adding the ability to run most tests on builds that disable OpenSSL support, better support for running tests under Valgrind and a number of bug-fixes. * ssh(1), sshd(8): check for convtime() refusing to accept times that resolve to LONG_MAX Reported by Kirk Wolf bz2977 * ssh(1): slightly more instructive error message when the user specifies multiple -J options on the command-line. bz3015 * ssh-agent(1): process agent requests for RSA certificate private keys using correct signature algorithm when requested. bz3016 * sftp(1): check for user@host when parsing sftp target. This allows user@[1.2.3.4] to work without a path. bz#2999 * sshd(8): enlarge format buffer size for certificate serial number so the log message can record any 64-bit integer without truncation. bz#3012 * sshd(8): for PermitOpen violations add the remote host and port to be able to more easily ascertain the source of the request. Add the same logging for PermitListen violations which where not previously logged at all. * scp(1), sftp(1): use the correct POSIX format style for left justification for the transfer progress meter. bz#3002 * sshd(8) when examining a configuration using sshd -T, assume any attribute not provided by -C does not match, which allows it to work when sshd_config contains a Match directive with or without -C. bz#2858 * ssh(1), ssh-keygen(1): downgrade PKCS#11 "provider returned no slots" warning from log level error to debug. This is common when attempting to enumerate keys on smartcard readers with no cards plugged in. bz#3058 * ssh(1), ssh-keygen(1): do not unconditionally log in to PKCS#11 tokens. Avoids spurious PIN prompts for keys not selected for authentication in ssh(1) and when listing public keys available in a token using ssh-keygen(1). bz#3006 Portability ----------- * ssh(1): fix SIGWINCH delivery of Solaris for multiplexed sessions bz#3030 * ssh(1), sshd(8): fix typo that prevented detection of Linux VRF * sshd(8): add no-op implementation of pam_putenv to avoid build breakage on platforms where the PAM implementation lacks this function (e.g. HP-UX). bz#3008 * sftp-server(8): fix Solaris privilege sandbox from preventing the legacy sftp rename operation from working (was refusing to allow hard links to files owned by other users). bz#3036 * All: add a proc_pidinfo()-based closefrom() for OS X to avoid the need to brute-force close all high-numbered file descriptors. bz#3049 * sshd(8): in the Linux seccomp-bpf sandbox, allow mprotect(2) with PROT_(READ|WRITE|NONE) only. This syscall is used by some hardened heap allocators. Github PR#142 * sshd(8): in the Linux seccomp-bpf sandbox, allow the s390-specific ioctl for ECC hardware support. * All: use "doc" man page format if the mandoc(1) tool is present on the system. Previously configure would not select the "doc" man page format if mandoc was present but nroff was not. * sshd(8): don't install duplicate STREAMS modules on Solaris; check if STREAMS modules are already installed on a pty before installing since when compiling with XPG>=4 they will likely be installed already. Prevents hangs and duplicate lines on the terminal. bz#2945 and bz#2998, Checksums: ========== - SHA1 (openssh-8.1.tar.gz) = bf7b0c65a7c0afa5ba9c787f345b8a24fa459add - SHA256 (openssh-8.1.tar.gz) = vamkKxZTFfgxQXSxGeJ1vbuot0H3Vx9bNBgrvChSrFg= - SHA1 (openssh-8.1p1.tar.gz) = c44b96094869f177735ae053d92bd5fcab1319de - SHA256 (openssh-8.1p1.tar.gz) = AvXb7zg10HU1VvlzzVe0wZtrH2zSTANEXiOsd8obk/8= Please note that the SHA256 signatures are base64 encoded and not hexadecimal (which is the default for most checksum tools). The PGP key used to sign the releases is available as RELEASE_KEY.asc from the mirror sites. Reporting Bugs: =============== - Please read http://www.openssh.com/report.html Security bugs should be reported directly to openssh@openssh.com