some dropbear bugs

Togg togg at togg.de
Tue Aug 24 14:46:40 WST 2004


Hi all,

I am testing 0.44test2 and have some problems.

1. Failed reading '/etc/dropbear/dropbear_dss_host_key', disabling DSS

I generated the dss key with dropbear_key but dropbear does not accept it.
Rsa key is accepted though.
strace:

open("/etc/dropbear/dropbear_rsa_host_key", O_RDONLY) = 3
read(3,
"\0\0\0\7ssh-rsa\0\0\0\3\1\0\1\0\0\0\203\0\256\35\343A\373\346\231\252p\221\
275\247\247\356/\274^\323/&F*s\204\257f\254L\277)\210\37oD\30\313\3359H\2067
read(3, "", 1173)                       = 0
close(3)                                = 0
open("/etc/dropbear/dropbear_dss_host_key", O_RDONLY) = 3
read(3,
"\0\0\0\7ssh-dss\0\0\0\201\0\261\'z(\206\231\367v+\312[\36\312e\227y\374\207
\5\10\5\2\225\377\35Xd\367eQN>V\335\5\7I\367TB\210\253\236\4\265\200%\31Hp\0
read(3, "", 1140)                       = 0
close(3)                                = 0
write(2, "Failed reading \'/etc/dropbear/dropbear_dss_host_key\', disabling
DSS\n", 68Failed reading '/etc/dropbear/dropbear_dss_host_key', disabling
DSS
) = 68
-----------------------

2. I can't login to dropbear server: failed to open any pty

I have configured devfs so I only have /dev/pty/{m0 .. m255}. I am not
involved in pty/pts so a no glue what is going on here.
Please give me a hint :)

CONFIG_UNIX98_PTY is enabled in kernel. And I also have a /dev/ptmx on my
target system (I am crosscompiling for arm)
In config.h after ./configure I have HAVE_OPENPTY 1 and USE_DEV_PTMX
undefined. How can I force using PTMX - which may help me?

	
...
[pid  8562] open("/dev/ptyZa", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/dev/ptyp826", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file
or directory)
[pid  8562] open("/dev/ptyZb", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/dev/ptyp827", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file
or directory)
[pid  8562] open("/dev/ptyZc", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/dev/ptyp828", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file
or directory)
[pid  8562] open("/dev/ptyZd", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/dev/ptyp829", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file
or directory)
[pid  8562] open("/dev/ptyZe", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/dev/ptyp830", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file
or directory)
[pid  8562] open("/dev/ptyZf", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/dev/ptyp831", O_RDWR|O_NOCTTY) = -1 ENOENT (No such file
or directory)
[pid  8562] brk(0x4f000)                = 0x4f000
[pid  8562] time([9664])                = 9664
[pid  8562] open("/etc/config/TZ", O_RDONLY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/etc/config/TZ", O_RDONLY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/etc/config/TZ", O_RDONLY) = -1 ENOENT (No such file or
directory)
[pid  8562] getpid()                    = 8562
[pid  8562] rt_sigaction(SIGPIPE, {0x401164d4, [], 0x4000000}, {SIG_IGN}, 8)
= 0
[pid  8562] send(3, "<84>Jan  1 03:41:04 dropbear[8562]: failed to open any
/dev/pty?? devices", 73, 0) = 73
[pid  8562] rt_sigaction(SIGPIPE, {SIG_IGN}, NULL, 8) = 0
[pid  8562] select(6, [5], [], NULL, {20, 0}) = 1 (in [5], left {20, 0})
[pid  8562] gettimeofday({9664, 164996}, NULL) = 0
[pid  8562] read(5, "\0\210l\2249\33\236*\24\263m\340\22J\341\311", 16) = 16
[pid  8562] read(5,
"\216\3\5B\20\271\271\325\225\264\276i\226!A\373b\355u\314\262\245\300\364\2
03_.wp\36\366u\367l\373\303", 36) = 36
[pid  8562] time([9664])                = 9664
[pid  8562] open("/etc/config/TZ", O_RDONLY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/etc/config/TZ", O_RDONLY) = -1 ENOENT (No such file or
directory)
[pid  8562] open("/etc/config/TZ", O_RDONLY) = -1 ENOENT (No such file or
directory)
[pid  8562] getpid()                    = 8562
[pid  8562] rt_sigaction(SIGPIPE, {0x401164d4, [], 0x4000000}, {SIG_IGN}, 8)
= 0
[pid  8562] send(3, "<84>Jan  1 03:41:04 dropbear[8562]: no pty was
allocated, couldn\'t execute", 74, 0) = 74
-----------------------

3. dbclient segfaults if home/.ssh is not writeable. Dbclient tries to write
an known_host file. It should be specifiable if or if not such a file should
be written.


Regards,
Togg





More information about the Dropbear mailing list