From 03b4be77e50c01cd0463089e68bbe673362a897b Mon Sep 17 00:00:00 2001 From: johannst Date: Mon, 29 Aug 2022 20:27:58 +0000 Subject: deploy: 8de64474ded169db55cdd34be9c020ed13c4e5e7 --- linux/coredump.html | 2 +- linux/cryptsetup.html | 251 ++++++++++++++++++++++++++++++++++++++++++++++++ linux/index.html | 3 +- linux/ptrace_scope.html | 6 +- linux/systemd.html | 2 +- 5 files changed, 258 insertions(+), 6 deletions(-) create mode 100644 linux/cryptsetup.html (limited to 'linux') diff --git a/linux/coredump.html b/linux/coredump.html index 741ef90..957d1f1 100644 --- a/linux/coredump.html +++ b/linux/coredump.html @@ -75,7 +75,7 @@ diff --git a/linux/cryptsetup.html b/linux/cryptsetup.html new file mode 100644 index 0000000..0824407 --- /dev/null +++ b/linux/cryptsetup.html @@ -0,0 +1,251 @@ + + + + + + cryptsetup - Notes + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ +
+ + + + + + + +
+
+

cryptsetup(8)

+
cryptsetup <action> [opts] <action args>
+
+action:
+    open <dev> <name> --type <type>    Open (decrypt) <dev> and map with <name>.
+                                       Mapped as /dev/mapper/<name>.
+                                       Type: {luks,plain,tcrypt,bitlk}
+    close <name>                       Close existing mapping <name>.
+    status <name>                      Print status for mapping <name>.
+
+    luksFormat <dev>                   Create new LUKS partition and set initial passphrase.
+                                       (Keyslot 0)
+    luksAddKey <dev>                   Add a new passphrase.
+    luksRemoveKey <dev>                Remove existing passphrase.
+    luksChangeKey <dev>                Change existing passphrase.
+    lusDump <dev>                      Dump LUKS header for device.
+
+

Example: Create LUKS encrypted disk.

+

For this example we use a file as backing storage and set it up as +loop(4) device. The loop device can be replaced by any block +device file.

+
+

Optional: Overwrite existing data on disk.
+sudo dd if=/dev/urandom of=/dev/sdX bs=1M

+
+

First create the backing file and setup the loop device.

+
# Create 100MB file.
+dd if=/dev/zero of=blkfile bs=1M count=100
+
+# Attach file to first free (-f) loop device
+sudo losetup -f ./blkfile
+# List loop devices.
+sudo losetup -l
+# NAME       SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE              DIO LOG-SEC
+# /dev/loop0         0      0         0  0 /home/johannst/blkfile   0     512
+
+

Create a new LUKS partition and format new filesystem.

+
# Initialize LUKS partition and set initial passphrase.
+sudo cryptsetup luksFormat /dev/loop0
+
+file blkfile
+# blkfile: LUKS encrypted file, ver 2 [, , sha256] UUID: 8...
+
+# Open (decrypt) the LUKS device, it will be mapped under /dev/mapper/loop0.
+sudo cryptsetup open --type luks /dev/loop0 loop0
+
+# Format partition with new filesystem.
+sudo mkfs.vfat /dev/mapper/loop0
+
+lsblk -f
+# NAME        FSTYPE    FSVER LABEL  UUID  FSAVAIL FSUSE% MOUNTPOINTS
+# loop0       crypto_LU 2            8...
+# └─loop0     vfat      FAT16        D...    83.8M     0% /home/johannst/mnt
+
+# Close (re-encrypt) LUKS device.
+sudo cryptsetup close loop0
+
+

Example: Using an existing LUKS device.

+
# Open (decrypt) the LUKS device, it will be mapped under /dev/mapper/loop0.
+sudo cryptsetup open --type luks /dev/loop0 loop0
+
+# Mount filesystem.
+sudo mount /dev/mapper/loop0 <mntpoint>
+
+# Use disk ...
+
+# Unmount filesystem.
+sudo umount <mntpoint>
+
+# Close (re-encrypt) LUKS device.
+sudo cryptsetup close loop0
+
+ +
+ + +
+
+ + + +
+ + + + + + + + + + + + diff --git a/linux/index.html b/linux/index.html index eec2957..1afccc2 100644 --- a/linux/index.html +++ b/linux/index.html @@ -75,7 +75,7 @@ @@ -142,6 +142,7 @@
  • systemd
  • coredump
  • ptrace_scope
    • +
  • cryptsetup
    • diff --git a/linux/ptrace_scope.html b/linux/ptrace_scope.html index 7c6d13b..8ed72d6 100644 --- a/linux/ptrace_scope.html +++ b/linux/ptrace_scope.html @@ -75,7 +75,7 @@ @@ -160,7 +160,7 @@ -
    @@ -172,7 +172,7 @@ - diff --git a/linux/systemd.html b/linux/systemd.html index e1a7a03..1dfaea2 100644 --- a/linux/systemd.html +++ b/linux/systemd.html @@ -75,7 +75,7 @@ -- cgit v1.2.3