1E4CRYPT(8) System Manager's Manual E4CRYPT(8)
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6 e4crypt - ext4 file system encryption utility
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9 e4crypt add_key -S [ -k keyring ] [-v] [-q] [ -p pad ] [ path ... ]
10 e4crypt new_session
11 e4crypt get_policy path ...
12 e4crypt set_policy [ -p pad ] policy path ...
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15 e4crypt performs encryption management for ext4 file systems.
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18 e4crypt add_key [-vq] [-S salt ] [-k keyring ] [ -p pad ] [ path ... ]
19 Prompts the user for a passphrase and inserts it into the speci‐
20 fied keyring. If no keyring is specified, e4crypt will use the
21 session keyring if it exists or the user session keyring if it
22 does not.
23 The salt argument is interpreted in a number of different ways,
25 depending on how its prefix value. If the first two characters
26 are "s:", then the rest of the argument will be used as an text
27 string and used as the salt value. If the first two characters
28 are "0x", then the rest of the argument will be parsed as a hex
29 string as used as the salt. If the first characters are "f:"
30 then the rest of the argument will be interpreted as a filename
31 from which the salt value will be read. If the string begins
32 with a '/' character, it will similarly be treated as filename.
33 Finally, if the salt argument can be parsed as a valid UUID,
34 then the UUID value will be used as a salt value.
35 The keyring argument specifies the keyring to which the key
37 should be added.
38 The pad value specifies the number of bytes of padding will be
40 added to directory names for obfuscation purposes. Valid pad
41 values are 4, 8, 16, and 32.
42 If one or more directory paths are specified, e4crypt will try
44 to set the policy of those directories to use the key just added
45 by the add_key command. If a salt was explicitly specified,
46 then it will be used to derive the encryption key of those di‐
47 rectories. Otherwise a directory-specific default salt will be
48 used.
49 e4crypt get_policy path ...
51 Print the policy for the directories specified on the command
52 line.
53 e4crypt new_session
55 Give the invoking process (typically a shell) a new session
56 keyring, discarding its old session keyring.
57 e4crypt set_policy [ -p pad ] policy path ...
59 Sets the policy for the directories specified on the command
60 line. All directories must be empty to set the policy; if the
61 directory already has a policy established, e4crypt will vali‐
62 date that the policy matches what was specified. A policy is an
63 encryption key identifier consisting of 16 hexadecimal charac‐
64 ters.
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67 Written by Michael Halcrow <mhalcrow@google.com>, Ildar Muslukhov <mus‐
68 lukhovi@gmail.com>, and Theodore Ts'o <tytso@mit.edu>
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71 keyctl(1), mke2fs(8), mount(8).
72E2fsprogs version 1.46.5 December 2021 E4CRYPT(8)