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Ed Maste 8c22023ca5 ssh: disable RSA/SHA-1 signatures
From OpenSSH 8.8p1's release notes:

---

Potentially-incompatible changes
================================

This release disables RSA signatures using the SHA-1 hash algorithm
by default. This change has been made as the SHA-1 hash algorithm is
cryptographically broken, and it is possible to create chosen-prefix
hash collisions for <USD$50K [1]

For most users, this change should be invisible and there is
no need to replace ssh-rsa keys. OpenSSH has supported RFC8332
RSA/SHA-256/512 signatures since release 7.2 and existing ssh-rsa keys
will automatically use the stronger algorithm where possible.

Incompatibility is more likely when connecting to older SSH
implementations that have not been upgraded or have not closely tracked
improvements in the SSH protocol. For these cases, it may be necessary
to selectively re-enable RSA/SHA1 to allow connection and/or user
authentication via the HostkeyAlgorithms and PubkeyAcceptedAlgorithms
options. For example, the following stanza in ~/.ssh/config will enable
RSA/SHA1 for host and user authentication for a single destination host:

    Host old-host
        HostkeyAlgorithms +ssh-rsa
	PubkeyAcceptedAlgorithms +ssh-rsa

We recommend enabling RSA/SHA1 only as a stopgap measure until legacy
implementations can be upgraded or reconfigured with another key type
(such as ECDSA or Ed25519).

[1] "SHA-1 is a Shambles: First Chosen-Prefix Collision on SHA-1 and
    Application to the PGP Web of Trust" Leurent, G and Peyrin, T
    (2020) https://eprint.iacr.org/2020/014.pdf

---

Relnotes:	Yes
Sponsored by:	The FreeBSD Foundation
2021-12-19 11:03:45 -05:00
.cirrus-ci Cirrus-CI: add some timing info on pkg install failure 2021-08-04 15:02:00 -04:00
.github [skip ci] fix syntax in CODEOWNERS 2021-07-22 10:58:54 -06:00
bin sh: Avoid some headers when NO_HISTORY is set. 2021-11-24 17:53:39 -08:00
cddl dtrace: Disable getf() as it is broken on FreeBSD 2021-12-17 13:10:22 -05:00
contrib Merge bmake-20211212 2021-12-18 10:09:14 -08:00
crypto ssh: disable RSA/SHA-1 signatures 2021-12-19 11:03:45 -05:00
etc Add idle priority scheduling privilege group to MAC/priority 2021-12-10 04:54:48 +02:00
gnu libdialog: Bump shared library version to 10. 2021-10-27 09:30:24 -07:00
include sched.h: Use pid_t type for pid argument 2021-12-17 08:22:21 +02:00
kerberos5 pkgbase: Create a FreeBSD-kerberos package 2021-09-07 10:23:14 +02:00
lib Move ve_check_hash prototype to libsecureboot-priv.h 2021-12-18 16:34:58 -08:00
libexec hostapd: Fix wlan interfaces not UP/RUNNING 2021-12-14 06:18:37 -08:00
release release: riscv64 - increase GENERICSD image size 2021-12-15 15:26:22 -05:00
rescue Retire synchronous PPP kernel driver sppp(4). 2021-10-22 11:41:36 -07:00
sbin fsutil: forward declare struct fstab 2021-12-15 19:38:28 -07:00
secure OpenSSL: Merge OpenSSL 1.1.1m 2021-12-14 16:03:52 -05:00
share Update dirdeps.mk et al to 20211212 versions 2021-12-18 13:37:07 -08:00
stand loader.efi: Do not use as frame buffer BLT-only GOPs. 2021-12-16 11:44:34 -05:00
sys inet6: fix a LOR between rip and rawinp 2021-12-19 14:43:04 +00:00
targets Retire obsolete iscsi_initiator(4) 2021-10-26 16:17:35 -04:00
tests tests: Add some regression tests for a couple of KERN_PROC_* sysctls 2021-12-17 13:10:52 -05:00
tools test-includes: update badfiles.inc 2021-12-17 12:38:36 +01:00
usr.bin After-import bmake-20211212 2021-12-18 10:14:39 -08:00
usr.sbin bhyve: Only snapshot initialized VirtIO queues 2021-12-17 13:06:53 -05:00
.arcconfig Remove history.immutable from .arcconfig 2021-04-13 12:36:25 +01:00
.arclint arc lint: ignore /tests/ in chmod 2017-12-19 03:38:06 +00:00
.cirrus.yml Cirrus-CI: build with LLVM 13 package 2021-11-18 09:57:33 -05:00
.clang-format clang-format: Add bitset loop macros 2021-09-21 12:08:01 -04:00
.gitattributes Add a basic clang-format configuration file 2019-06-07 15:23:52 +00:00
.gitignore gitignore: Add .clangd and .ccls-cache 2021-06-04 16:56:08 +08:00
COPYRIGHT copyrights: Happy New Year 2021 2020-12-31 10:29:44 -05:00
LOCKS LOCKS: update current locks 2018-06-09 03:08:04 +00:00
MAINTAINERS Remove myself from bhyve maintenance; ENOTIME. 2021-11-19 07:09:30 +10:00
Makefile Import bmake-20211212 2021-12-17 23:27:22 -08:00
Makefile.inc1 test-includes: Build a library instead of a binary 2021-12-15 15:35:24 -07:00
Makefile.libcompat libcompat: Remove MIPS from list of compat libraries 2021-12-09 08:22:51 -07:00
Makefile.sys.inc AUTO_OBJ: For all top-level targets enforce using an OBJDIR. 2017-12-05 21:29:47 +00:00
ObsoleteFiles.inc man: Remove obsolete meteor.4 2021-12-18 14:56:16 +01:00
README.md README.md: update gnu directory description 2021-12-17 08:45:31 -05:00
RELNOTES RELNOTES: Note support for KTLS RX for TLS 1.3. 2021-12-14 11:02:45 -08:00
UPDATING Test various header files to ensure they can be included by themselves. 2021-12-14 20:25:37 -07:00

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