On Wednesday, 11 April 2018 21:39:30 BST Ben Mezger wrote: > Greetings, > > I have enabled module signature verification on my kernel, and it does > seem to be enabled upon boot: > > $ dmesg | grep -i 'x.*509' > [ 1.259988] Asymmetric key parser 'x509' registered > [ 1.811026] Loading compiled-in X.509 certificates > [ 1.813833] Loaded X.509 cert 'Build time autogenerated kernel key: > 77e716fc52a6293567d953cd24a5977e55b41a5e' > > and doing a cat /proc/keys seems to show the key enabled: > > $ cat /proc/keys > ... > 37c67374 I------ 1 perm 1f030000 0 0 asymmetri Build time > autogenerated kernel key: 77e716fc52a6293567d953cd24a5977e55b41a5e: > X509.rsa 55b41a5e [] > ... > > However, if I do a modinfo to see the key on a module, it seems empty: > > $modinfo ntfs > filename: /lib/modules/4.9.76-gentoo-r1/kernel/fs/ntfs/ntfs.ko > license: GPL > version: 2.1.32 > description: NTFS 1.2/3.x driver - Copyright (c) 2001-2014 Anton > Altaparmakov and Tuxera Inc. > author: Anton Altaparmakov <an...@tuxera.com> > alias: fs-ntfs > srcversion: 0D7ACE93F603E9350827FB8 > depends: > intree: Y > vermagic: 4.9.76-gentoo-r1 SMP mod_unload > signat: PKCS#7 > signer: > sig_key: > sig_hashalgo: md4
I am getting a similar output with later source kernel than yours:
# modinfo ntfs
filename: /lib/modules/4.15.17-gentoo/kernel/fs/ntfs/ntfs.ko.gz
license: GPL
version: 2.1.32
description: NTFS 1.2/3.x driver - Copyright (c) 2001-2014 Anton
Altaparmakov and Tuxera Inc.
author: Anton Altaparmakov <an...@tuxera.com>
alias: fs-ntfs
srcversion: B6DF5EBF4EF8B063988F5CB
depends:
retpoline: Y
intree: Y
name: ntfs
vermagic: 4.15.17-gentoo SMP preempt mod_unload
signat: PKCS#7
signer:
sig_key:
sig_hashalgo: md4
Which I find quite confusing. Not only the keys are not shown, but the
sig_hashalgo is md4 (cracked since 1995) instead of the SHA512 I had specified
in my kernel .config.
> And hex dump does show me the digital signature appended at the end:
>
> $ hexdump -C /lib64/modules/4.9.76-gentoo-r1/kernel/fs/ntfs/ntfs.ko| tail
> 0004e8c0 e3 dd 54 9d 5e f1 1a 12 56 47 4e 54 91 b9 fa ce
> |..T.^...VGNT....| 0004e8d0 e6 01 db 37 eb 83 f3 77 10 f0 b5 f8 11 fd 4e
> 86 |...7...w......N.| 0004e8e0 6c 81 8a 61 c2 15 6d 5a 35 93 8b 33 c0 32
> 2f e4 |l..a..mZ5..3.2/.| 0004e8f0 8c 15 71 de c8 c5 39 58 cc e8 65 e1 be
> 36 e6 02 |..q...9X..e..6..| 0004e900 b0 75 b5 a2 73 d8 4d 22 e7 2f 53 1f
> 42 fb ee 58 |.u..s.M"./S.B..X| 0004e910 f2 65 44 13 26 30 7b 31 1c 58 12
> 5a f2 5d b1 45 |.eD.&0{1.X.Z.].E| 0004e920 3a f0 a5 79 74 f4 00 00 02 00
> 00 00 00 00 00 00 |:..yt...........| 0004e930 02 9e 7e 4d 6f 64 75 6c 65
> 20 73 69 67 6e 61 74 |..~Module signat| 0004e940 75 72 65 20 61 70 70 65
> 6e 64 65 64 7e 0a |ure appended~.| 0004e94e
>
> My question is: why doesn't modinfo show me the key fingerprint?
I don't know the answer, but would be interested to find out. I have only
used kernel autogenerated keys to do this, so I can't attest if the result is
the same when creating own keys manually.
--
Regards,
Mick
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