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