Re: [PATCH] crypto: af_alg - Add af_alg_restrict sysctl, defaulting to 1

[Eric Biggers <ebiggers@kernel.org>]

On Tue, Jun 23, 2026 at 02:28:17PM -0700, Rosen Penev wrote:
> > +static const struct af_alg_allowlist_entry hash_allowlist[] = {
> > +       { "cmac(aes)", true }, /* iwd, bluez */
> > +       { "hmac(md5)", true }, /* iwd */
> > +       { "hmac(sha1)", true }, /* iwd */
> > +       { "hmac(sha224)", true }, /* iwd */
> > +       { "hmac(sha256)", true }, /* iwd */
> > +       { "hmac(sha384)", true }, /* iwd */
> > +       { "hmac(sha512)", true }, /* iwd, sha512hmac */
> > +       { "md4", true }, /* iwd */
> > +       { "md5", true }, /* iwd */
> > +       { "sha1", false }, /* iwd, iproute2 < 7.0 */
> > +       { "sha224", true }, /* iwd */
> > +       { "sha256", true }, /* iwd */
> > +       { "sha384", true }, /* iwd */
> > +       { "sha512", true }, /* iwd */
> > +       {},
> In OpenWrt, https://gitlab.com/linux-afs/kafs-client and strongswan
> seem to be the other users of the user API. I haven't looked into what
> they need.

[Please trim your replies, thanks!]

https://gitlab.com/linux-afs/kafs-client uses AF_ALG only for
"hmac(md5)", which I already put on the privileged allowlist due to iwd
also using it.  So it would still work by default with the current
patch, unless it needs to use it unprivileged.

(FWIW, a use of a single obsolete algorithm like this is also a good
candidate for just replacing with local code...)

https://github.com/strongswan/strongswan already supports userspace
crypto libraries.

- Eric