check user names carefully for null-termination and characters.
something (a power glitch, i believe) added a lot of junk to my
/adm/keys file:

ladd# 8.keyfs
name 0 bad: [00][11][30][11][5b][31][0c][00][00][00][00][00][00][00][00][00][00][00][00][00][00][00][00][00][00][00][00][00]
name 1 no termination: [0c][30])[5d]P[33][08]`u[5b]+[64]:[50][5b][33]zB[5b]2t[5d][60][75][5b]k[62][5d]
name 2 no termination: f[00][06][30][5d][5b]T[36][5d]S<[30]\QF׼[5b][35][04][5d]UB[33]vq[5b][35]
name 3 no termination: ֲ~[00][30]ev[5b][33][30][5d][65][76]MEP->[33][33][5d]>=[30][5d]kK[05]
name 4 no termination: ֲ~[00][30]ev[5b][33][30][5d][65][76]MEP->[33][33][5d]>=[30][5d]kK[05]
name 6 no termination: P[17]DJ[5d]|[4a]"C<$5[5b][c[5d]0L[0d][03]*[5b][0c][62][5d][5b]N4
name 7 no termination: [50]i[30]F\gaIX[1c][5c][67]u[0c][09][1e][31][15][5d][5b][35][63][05]ۦ؁j
name 9 no termination: [1b]2[62][5d]0[5b]sӖ5[35]:[5d]Q[5b]U[11][5d]OD[-6a]ZX:[35][5d][3a][5b]
name 10 no termination: [5b][35][62][1e][5b][33][35][16][[03][1c][01]:[31][14][1d][5b]_f[5d][5b][33][0a][5d][5b][33][35][5d]
name 12 no termination: ~[00]r[30]X>[5b][1e]%@[58]oOq[62][5d]ƳA@[25][40]g[35][38][05]%_
name 14 no termination: [1e][31]o[5d][5b]Ę5Y[17][0f]H$[5b][08][62][1b]H[-68]P[59][5b][31][14][5d][5b]\[66]
4 keys read