Illegal instruction in AES ciphers on WinChip C6

[Dick Streefland]

Binary package hint: openssl

Some ciphers from openssl-0.9.8k-7ubuntu8 in Ubuntu 10.04 terminate with an Illegal instruction signal (SIGILL) when running on a WinChip C6 processor:

$ cat openssl.sh
#!/bin/sh
for c in `openssl list-cipher-commands`
do
        echo $c
        echo -n Hello | openssl enc -$c -K 0 -iv 0 > /dev/null
done
$ openssl.sh
aes-128-cbc
Illegal instruction
aes-128-ecb
Illegal instruction
aes-192-cbc
Illegal instruction
aes-192-ecb
Illegal instruction
aes-256-cbc
Illegal instruction
aes-256-ecb
Illegal instruction
base64
bf
bf-cbc
bf-cfb
bf-ecb
bf-ofb
cast
cast-cbc
cast5-cbc
cast5-cfb
cast5-ecb
cast5-ofb
des
des-cbc
des-cfb
des-ecb
des-ede
des-ede-cbc
des-ede-cfb
des-ede-ofb
des-ede3
des-ede3-cbc
des-ede3-cfb
des-ede3-ofb
des-ofb
des3
desx
rc2
rc2-40-cbc
rc2-64-cbc
rc2-cbc
rc2-cfb
rc2-ecb
rc2-ofb
rc4
rc4-40

I'm using a default kernel:

$ uname -a
Linux vdr 2.6.32-22-386 #36-Ubuntu SMP Fri Jun 4 00:27:09 UTC 2010 i586 GNU/Linux

This is the CPU info:

$ cat /proc/cpuinfo
processor : 0
vendor_id : CentaurHauls
cpu family : 5
model : 4
model name : WinChip C6
stepping : 1
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu de msr mce cx8 mmx centaur_mcr up
bogomips : 399.48
clflush size : 32
cache_alignment : 32
address sizes : 32 bits physical, 32 bits virtual
power management:

I ran into this when I couldn't access this machine via ssh 4.7p1, because this version selects the aes128-cbc cipher by default. Ssh immediately terminates with "Connection closed by ...".

[Oibaf (oibaf)]

Can you check if this 12 years old bug is still the case on a currently supported Ubuntu release?
https://wiki.ubuntu.com/Releases

[Dick Streefland (dick-streefland)]

No, I can't check because I don't have the hardware anymore.

[Launchpad Janitor (janitor)]

[Expired for openssl (Ubuntu) because there has been no activity for 60 days.]