On 2026/09/30 09:59, Mikolaj Kucharski wrote: > Hi. > > I'm trying to remove some old IPs from `~/.ssh/known_hosts` file. > > $ ssh-keygen -R <ip-addr> > /home/user123/.ssh/known_hosts:846: invalid line > # Host <ip-addr> found: line 859 > # Host <ip-addr> found: line 860 > # Host <ip-addr> found: line 861 > /home/user123/.ssh/known_hosts is not a valid known_hosts file. > Not replacing existing known_hosts file because of errors
It is expected that lines with unknown algorithm types (here [email protected]) trigger this in ssh-keygen -R. It is annoying though. (my usage of ssh-keygen -R is usually "ssh-keygen -R user@host" from <esc> _ to copy in the last word from the ssh command, "dammit", and edit to remove the username...) > $ echo $? > 1 > > $ sed -ne '846p' < ~/.ssh/known_hosts | sed -e 's/^[^[:blank:]]*/<redacted>/' > | tr A-Z . > <redacted> [email protected] > .....3.za.1tb..z...0...k.j.1..l.b3.lbn.za.5jb20.....c8emx..yw7u8d.w..v.......iu.crc7.4f.m3xn.eq.n.+.azg.0.a1.y...0smu.8io..f..z.ap45..w...t.v1b.s.wocgy1...6.d..xr9c...1g...a.+.t..8f.3x9h...6..p..03nlg....ve.06y..740c...qlw05k1.440a..0.5jb.3.3./j.8.0./4.htq.r+i....h8z.f.j...w.ly.je.kk..cwe+1w..g.v.4..3l....9mmor.h.q/...lyv6d..+s.o.7l..de+..+2o...i.vo.4.k.w.i.b.9v.1...ey.nhym.7ak.6.jbh.e.+g.3na9.xlz.cy...02k9..a...73.t..gfs7p..3c.h9.7xn.qv.0.c.....n.q../....uq.0l7p.2ypsr7kt.04.kh....../dni...d3qq.bcjj..vj5.9i.3..um1u.m5.hejh.6t3trpwxj.us.sfs..31.ma.ipq.0z61sg.pqg06z.4+.b8.qv..z.po.e.6q3.+..grr.+0...9..y3.e3.4.e.hna.j7a/...t.38g....loj...w.6el.j6fwnle..i0gt28cms...jy....2.y..p+0ob3i9.g.gwrf.x.8.gvcoko3.7...2.n9o.he4rjb/va5...822..696vhrq44.4..3.w.j/1..+..dzyv.7r...pj...tj9..r..kqrr..h.o.i....c4c..6..i0u...6oda.g...oqkx...24..l6....air.0....g..4pd8gwy...u.9.w.w...6./v/.o.a.9..zcyrsd4..24.qg...iw8.h.t.a...g...votd78...0.....w.h1......190.05.e/..n..jkp.jsh.nz.lh.f.v.6.m.5am.41z.qa43z...s.zhn/.h8t.avecu.ih.iwm..f+..wk.zzcpl.mjs./.t.7/.t..wfo.l...hr.g2jqi..4.f.cxrn/gc21.52..fg40..j.dm.l6plec.4u..ux9..ym.0.22r.j.n.c.54ll..wnf..cdh1..l..s.wvab.l....v.5.c+v10/7gc.9..15.o3m..i3...7.zx..61....6h..h..ys2i.p..h.m533..../31.n9....h.41mha350...psv0..7d2...7.7.wlx.9i..2r...h2.x.j.8.0.7.n.....zch.pe1l..o2s2..6eo..tio.7...7wyn.uf/s/3..42b.y.b.l.k9.h.m.z.kn7..7.8eu...c9.f8.qge9i7sehw.kza8rn7m31nc...f..n8.r.9kl.k.3.aidd.kk.94f/gvjj.otw..m4.cwk3..sxy.n+cjo..11v/..+h.3vqd.lxg.v.6j.j.1hxv...y....8yk..1.sq.c8up./.csu.+z.9n....w..a1y..i.nm5x/y.os/..pj...oc6a....drb.3...u.9p..si..3.q.2xn..g.1lif.0..lxh.4m68..quh.p.3b5x....ub.c.k.v...f/mz6..i5yo..7+gea./j.fmk.pd.1g..32+pmdp....qrxgj..qiajferw8a./fuw.+.tru..j.0mb.t4.ffw2.e2x.oi...j..3d..sd7.b/..+7.h..j3.8..74.6.j.tepa.n.j.......l.z4.r.q09x.c.k1.dsnjvvb.gvw.13/.8..qm..s.....j..z..3..e8.pw.+sc1 > > Would that be expected behaviour? I understand that > [email protected] is removed (or renamed) from (in) OpenSSH, > but not sure does it qualify as a bug. > > Unless the line 846 is really malformed? It's typical SSH pubkey line, > similar to the one in: > > /etc/ssh/ssh_host_mldsa44_ed25519_key.pub that tr(1) makes it hard to grasp the format of the line and makes it look like some binary junk, but based on what you say, this chunk is just a regular b64-encoded string and not malformed
