Date: Sat, 28 Dec 2019 23:58:44 -0600 From: Clay Daniels <clay.daniels.jr@gmail.com> To: "freebsd-questions@freebsd.org" <freebsd-questions@freebsd.org> Subject: Re: Reading nvram efi variables Message-ID: <CAGLDxTUNwJFpo8RLnrgZTY7LYN539vYCRd0%2BwpEfMYQ0uxoPSQ@mail.gmail.com> In-Reply-To: <CAGLDxTUZoXhWHFXBy4qoYjWPUk%2B3nf%2Bp1xpk1U6mU80=5Y4Z_g@mail.gmail.com> References: <CAGLDxTUZoXhWHFXBy4qoYjWPUk%2B3nf%2Bp1xpk1U6mU80=5Y4Z_g@mail.gmail.com>
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Actually I intended to write it as a binary file with the -b option: root@bsd13:/bootkeys # efivar -n 8be4df61-93ca-11d2-aa0d-00e098032b8c-dbxDefault -b > dbx root@bsd13:/bootkeys # hexdump -C dbx 00000000 26 16 c4 c1 4c 50 92 40 ac a9 41 f9 36 93 43 28 |&...LP.@ ..A.6.C(| 00000010 8c 0e 00 00 00 00 00 00 30 00 00 00 bd 9a fa 77 |........0......w| 00000020 59 03 32 4d bd 60 28 f4 e7 8f 78 4b 80 b4 d9 69 |Y.2M.`(...xK...i| 00000030 31 bf 0d 02 fd 91 a6 1e 19 d1 4f 1d a4 52 e6 6d |1.........O..R.m| 00000040 b2 40 8c a8 60 4d 41 1f 92 65 9f 0a bd 9a fa 77 |.@..`MA..e.....w| 00000050 59 03 32 4d bd 60 28 f4 e7 8f 78 4b f5 2f 83 a3 |Y.2M.`(...xK./..| 00000060 fa 9c fb d6 92 0f 72 28 24 db e4 03 45 34 d2 5b |......r($...E4.[| 00000070 85 07 24 6b 3b 95 7d ac 6e 1b ce 7a bd 9a fa 77 |..$k;.}.n..z...w| ~ 00000ec0 9c a5 44 e6 bb 78 0a 2c 78 90 1d 3f b3 37 38 76 |..D..x.,x..?.78v| 00000ed0 85 11 a3 06 17 af a0 1d 38 62 65 34 64 66 36 31 |........8be4df61| 00000ee0 2d 39 33 63 61 2d 31 31 64 32 2d 61 61 30 64 2d |-93ca-11d2-aa0d-| 00000ef0 30 30 65 30 39 38 30 33 32 62 38 63 2d 64 62 78 |00e098032b8c-dbx| 00000f00 44 65 66 61 75 6c 74 0a 0a |Default..| 00000f09 root@bsd13:/bootkeys # On Sat, Dec 28, 2019 at 11:46 PM Clay Daniels <clay.daniels.jr@gmail.com> wrote: > The efivar command will list efi variables using: > # efivar -l > ~ > 8be4df61-93ca-11d2-aa0d-00e098032b8c-dbxDefault > 8be4df61-93ca-11d2-aa0d-00e098032b8c-dbDefault > 8be4df61-93ca-11d2-aa0d-00e098032b8c-KEKDefault > 8be4df61-93ca-11d2-aa0d-00e098032b8c-PKDefault > ~ > (There are a lot more but these secure boot keys are the ones of interest > to me) > > I can write them to a file with: > # efivar -n 8be4df61-93ca-11d2-aa0d-00e098032b8c-dbxDefault > dbx > > I can sort of read it with hexdump: > root@bsd13:/bootkeys # hexdump -C dbx > 00000000 38 62 65 34 64 66 36 31 2d 39 33 63 61 2d 31 31 > |8be4df61-93ca-11| > 00000010 64 32 2d 61 61 30 64 2d 30 30 65 30 39 38 30 33 > |d2-aa0d-00e09803| > 00000020 32 62 38 63 2d 64 62 78 44 65 66 61 75 6c 74 0a > |2b8c-dbxDefault.| > 00000030 30 30 30 30 3a 20 32 36 20 31 36 20 63 34 20 63 |0000: 26 16 > c4 c| > 00000040 31 20 34 63 20 35 30 20 39 32 20 34 30 20 61 63 |1 4c 50 92 40 > ac| > 00000050 20 61 39 20 34 31 20 66 39 20 33 36 20 39 33 20 | a9 41 f9 36 > 93 | > 00000060 34 33 20 32 38 20 0a 30 30 31 30 3a 20 38 63 20 |43 28 .0010: > 8c | > 00000070 30 65 20 30 30 20 30 30 20 30 30 20 30 30 20 30 |0e 00 00 00 > 00 0| > 00000080 30 20 30 30 20 33 30 20 30 30 20 30 30 20 30 30 |0 00 30 00 00 > 00| > 00000090 20 62 64 20 39 61 20 66 61 20 37 37 20 0a 30 30 | bd 9a fa 77 > .00| > 000000a0 32 30 3a 20 35 39 20 30 33 20 33 32 20 34 64 20 |20: 59 03 32 > 4d | > 000000b0 62 64 20 36 30 20 32 38 20 66 34 20 65 37 20 38 |bd 60 28 f4 > e7 8| > 000000c0 66 20 37 38 20 34 62 20 38 30 20 62 34 20 64 39 |f 78 4b 80 b4 > d9| > 000000d0 20 36 39 20 0a 30 30 33 30 3a 20 33 31 20 62 66 | 69 .0030: 31 > bf| > 000000e0 20 30 64 20 30 32 20 66 64 20 39 31 20 61 36 20 | 0d 02 fd 91 > a6 | > 000000f0 31 65 20 31 39 20 64 31 20 34 66 20 31 64 20 61 |1e 19 d1 4f > 1d a| > 00000100 34 20 35 32 20 65 36 20 36 64 20 0a 30 30 34 30 |4 52 e6 6d > .0040| > 00000110 3a 20 62 32 20 34 30 20 38 63 20 61 38 20 36 30 |: b2 40 8c a8 > 60| > 00000120 20 34 64 20 34 31 20 31 66 20 39 32 20 36 35 20 | 4d 41 1f 92 > 65 | > 00000130 39 66 20 30 61 20 62 64 20 39 61 20 66 61 20 37 |9f 0a bd 9a > fa 7| > 00000140 37 20 0a 30 30 35 30 3a 20 35 39 20 30 33 20 33 |7 .0050: 59 > 03 3| > 00000150 32 20 34 64 20 62 64 20 36 30 20 32 38 20 66 34 |2 4d bd 60 28 > f4| > 00000160 20 65 37 20 38 66 20 37 38 20 34 62 20 66 35 20 | e7 8f 78 4b > f5 | > 00000170 32 66 20 38 33 20 61 33 20 0a 30 30 36 30 3a 20 |2f 83 a3 > .0060: | > 00000180 66 61 20 39 63 20 66 62 20 64 36 20 39 32 20 30 |fa 9c fb d6 > 92 0| > 00000190 66 20 37 32 20 32 38 20 32 34 20 64 62 20 65 34 |f 72 28 24 db > e4| > 000001a0 20 30 33 20 34 35 20 33 34 20 64 32 20 35 62 20 | 03 45 34 d2 > 5b | > 000001b0 0a 30 30 37 30 3a 20 38 35 20 30 37 20 32 34 20 |.0070: 85 07 > 24 | > 000001c0 36 62 20 33 62 20 39 35 20 37 64 20 61 63 20 36 |6b 3b 95 7d > ac 6| > 000001d0 65 20 31 62 20 63 65 20 37 61 20 62 64 20 39 61 |e 1b ce 7a bd > 9a| > 000001e0 20 66 61 20 37 37 20 0a 30 30 38 30 3a 20 35 39 | fa 77 .0080: > 59| > 000001f0 20 30 33 20 33 32 20 34 64 20 62 64 20 36 30 20 | 03 32 4d bd > 60 | > 00000200 32 38 20 66 34 20 65 37 20 38 66 20 37 38 20 34 |28 f4 e7 8f > 78 4| > ~ > 00003300 63 20 37 38 20 39 30 20 31 64 20 33 66 20 62 33 |c 78 90 1d 3f > b3| > 00003310 20 33 37 20 33 38 20 37 36 20 0a 30 65 64 30 3a | 37 38 76 > .0ed0:| > 00003320 20 38 35 20 31 31 20 61 33 20 30 36 20 31 37 20 | 85 11 a3 06 > 17 | > 00003330 61 66 20 61 30 20 31 64 20 0a 0a |af a0 1d ..| > 0000333b > root@bsd13:/bootkeys # > > Does anyone have a way to get any more real information out of these files > in more humanly readable form? > > Clay >
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