--- name: "efisecdb" section: "1" platform: "linux" package: "efivar" version: "39-2" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/efisecdb" --- # efisecdb(1) utility for managing UEFI signature lists ## NAME **efisecdb** - utility for managing UEFI signature lists ## SYNOPSIS **efisecdb** \[**-s** *SORT*\] \[**-i** *file* \[**-i** *file*\] ...\] \[**-g** *guid* ⟨**-a** \| **-r**⟩ ⟨\[**-t** *hash-type*\] **-h** *hash* \| **-c** *file*⟩ \[**-g** *guid* ⟨**-a** \| **-r**⟩ ⟨\[**-t** *hash-type*\] **-h** *hash* \| **-c** *file*⟩\] ...\] ⟨**-d** \[**-A**\] \| **-o** *file* \| **-L**⟩ ## DESCRIPTION **efisecdb** is a command line utility for management of UEFI signature lists in detached files. That is, it's for command line generation and management of files in the format of KEK, DB, and DBX. Operation occurs in three phases: - 1\. Loading of security databases specified with **--input** - 2\. Left-to-right processing of other options, using **--hash-type,** **--owner-guid,** **--add,** and **--remove** as state to build selectors to add or remove hashes and certificates specified by **--hash** and **--certificate**. - 3\. Generation of output The accumulated state is persistent; once an Owner GUID, Add or Delete operation, or hash type are specified, they need only be present again to change the operations that follow. Operations are added to the list to process when **-h** *hash* or **-c** *cert* are specified, and are processed in the order they appear. Additionally, at least one **-g** argument and either **--add** or **--remove** must appear before the first use of **-h** *hash* or **-c** *cert*. ## OPTIONS - ⟨**-s** \| **--sort**⟩ ⟨*all* \| *data* \| *none* \| *type*⟩ Sort by data after sorting and grouping entry types, entry data, no sorting, or by entry type - ⟨**-s** \| **--sort**⟩ ⟨*ascending* \| *descending*⟩ Sort in ascending or descending order - **-i** *file* \| **--infile** *file* Read EFI Security Database from *file* - **-g** *guid* \| **--owner-guid** *guid* Use the specified GUID or symbolic refrence (i.e. {empty}) for forthcoming addition and removal operations - **-a** \| **--add** \| **-r** \| **--remove** Select *add* or *remove* for forthcoming operations - **-t** *hash-type* \| **--hash-type** *hash-type* Select *hash-type* for forthcoming addition and removal operations (default *sha256*) Use hash-type *help* to list supported hash types. - **-h** *hash* \| **--hash** *hash* Add or remove the specified hash - **-c** *file* \| **--certificate** *file* Add or remove the specified certificate - **-d** \| **--dump** Produce a hex dump of the output - **-A** \| **--annotate** Annotate the hex dump produced by **--dump** - **-o** *file* \| **--outfile** *file* Write EFI Security Database to *file* - **-L** \| **--list-guids** List the well known guids The output is tab delimited: GUID short\_name desription ## EXAMPLES ### Dumping the current system's *DBX* database with annotations ``` host:~$ efisecdb -d -A -i /sys/firmware/efi/efivars/dbx-d719b2cb-3d3a-4596-a3bc-dad00e67656f 00000000 26 16 c4 c1 4c 50 92 40 ac a9 41 f9 36 93 43 28 |&...LP.@..A.6.C(| esl[0].signature_type = {sha256} 00000010 60 00 00 00 |....| esl[0].signature_list_size = 96 00000014 00 00 00 00 |....| esl[0].signature_header_size = 0 00000018 30 00 00 00 |0...| esl[0].signature_size = 48 0000001c esl[0].signature_header (end:0x0000001c) 0000001c bd 9a fa 77 |...w| esl[0].signature[0].owner = {microsoft} 00000020 59 03 32 4d bd 60 28 f4 e7 8f 78 4b |Y.2M.`(...xK| 0000002c fe cf b2 32 |...2| esl[0].signature[0].data (end:0x0000004c) 00000030 d1 2e 99 4b 6d 48 5d 2c 71 67 72 8a a5 52 59 84 |...KmH],qgr..RY.| 00000040 ad 5c a6 1e 75 16 22 1f 07 9a 14 36 |...u."....6| 0000004c bd 9a fa 77 |...w| esl[0].signature[1].owner = {microsoft} 00000050 59 03 32 4d bd 60 28 f4 e7 8f 78 4b |Y.2M.`(...xK| 0000005c fe 63 a8 4f |.c.O| esl[0].signature[1].data (end:0x0000007c) 00000060 78 2c c9 d3 fc f2 cc f9 fc 11 fb d0 37 60 87 87 |x,..........7`..| 00000070 58 d2 62 85 ed 12 66 9b dc 6e 6d 01 |X.b...f..nm.| 0000007c ``` ### Building a new EFI Security Database for use as *KEK*, replacing one certificate. ``` # Figure out the original cert... the easy way host:~$ strings KEK-* | grep microsoft.*crt Dhttp://www.microsoft.com/pki/certs/MicCorThiParMarRoo_2010-10-05.crt0 # Find it, because --export isn't implemented yet host:~$ wget \ --user-agent='Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko' \ http://www.microsoft.com/pki/certs/MicCorThiParMarRoo_2010-10-05.crt --2020-06-04 20:41:27-- http://www.microsoft.com/pki/certs/MicCorThiParMarRoo_2010-10-05.crt Resolving www.microsoft.com (www.microsoft.com)... 2600:141b:800:287::356e, 2600:141b:800:2a0::356e, 23.43.254.254 Connecting to www.microsoft.com (www.microsoft.com)|2600:141b:800:287::356e|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 1539 (1.5K) [application/octet-stream] Saving to: ‘MicCorThiParMarRoo_2010-10-05.crt’ MicCorThiParMarRoo_ 100%[===================>] 1.50K --.-KB/s in 0s 2020-06-04 20:41:27 (177 MB/s) - ‘MicCorThiParMarRoo_2010-10-05.crt’ saved [1539/1539] # Pick a GUID-like object, any GUID-like object... host:~$ uuidgen aab3960c-501e-485e-ac59-62805970a3dd # Remove the old KEK entry and add a different one host:~$ efisecdb -i KEK-8be4df61-93ca-11d2-aa0d-00e098032b8c \ -g {microsoft} -r -c MicCorThiParMarRoo_2010-10-05.crt \ -g aab3960c-501e-485e-ac59-62805970a3dd -a -c pjkek.cer \ -o newkek.bin ``` ### Searching the list of well-known GUIDs ``` host:~$ efisecdb -L | grep shim {605dab50-e046-4300-abb6-3dd810dd8b23} {shim} shim ``` ## STANDARDS UEFI Specification Working Group, *Unified Extensible Firmware Interface (UEFI) Specification Version 2.8*, *Unified Extensible Firmware Interface Forum*, https://uefi.org/specifications , March 2019. ## SEE ALSO [authvar(1)](/authvar/1.md), [efikeygen(1)](/efikeygen/1.md), [pesign(1)](/pesign/1.md) ## AUTHORS Peter Jones ## BUGS **efisecdb** is currently lacking several useful features: - **•** positional exporting of certificates - **•** **--dump** and **--annotate** do not adjust the output width for the terminal - **•** certificates can't be specified for removal by their *ToBeSigned* hash