74 lines
2.3 KiB
Markdown
74 lines
2.3 KiB
Markdown
# luks_pkcs
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### Acknowledgment
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It has been tested on a debian laptop and a mobian pinephone.
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The smartcard generation come from inspired by https://github.com/swoopla/smartcard-luks .
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The OSK-SDL parts are inspired by Mobian package https://salsa.debian.org/DebianOnMobile-team/osk-sdl.
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### The general steps:
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* Erase and initialize card
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* Create public/private key pair on smartcard
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* Create key file and add it to a LUKS key slot
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* Encrypt key file using public key from smartcard
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* Modify initramfs to use smartcard to decrypt the encrypted keyfile
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* Modify decrypt_opensc script to swicth between smartcard and luks password and add osk-sdl support for touchscreen device
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### The details:
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1. Install smartcard middleware
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```sudo apt-get install pcscd opensc```
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2. Erase smartcard
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```pkcs15-init -E```
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3. Initialize smartcard
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```pkcs15-init --create-pkcs15 -p pkcs15+onepin --pin 1234 --puk 4321```
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4. Create public/private key pair on smartcard
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```pkcs15-init -G rsa/2048 -i 01 -a 01 -u decrypt --pin 1234```
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5. Create a random key file and add it to a LUKS key slot
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```sudo touch /root/rootkey```
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```sudo chmod 600 /root/rootkey```
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```sudo dd if=/dev/random of=/root/rootkey bs=1 count=245 #change to urandom if you can't wait```
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```sudo cryptsetup luksAddKey /dev/sda2 /root/rootkey```
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6. Export the public key from smartcard
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```pkcs15-tool --read-public-key 01 -o public_key_rsa2048.pem```
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7. Encrypt key file using public key
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```sudo openssl rsautl -encrypt -pubin -inkey public_key_rsa2048.pem -in /root/rootkey -out /root/rootkey.enc```
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```sudo rm /root/rootkey```
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8. Edit crypttab. This change sends the encrypted key file as a param to the keyscript
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This should be of the form:
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```mapped_device_name source_block_device key_file luks,keyscript=decrypt_pkcs```
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For example:
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```sda2_crypt UUID=d332ecc5-ce8b-4900-a04a-a79abd029d6d /root/rootkey.enc luks,keyscript=decrypt_pkcs```
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9. Install the cryptsetup script and the initramfs-tool hook
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```sudo cp decrypt_pkcs /lib/cryptsetup/script/ ```
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```sudo cp decrypt_pkcs_hook /etc/initramfs-tools/hooks && chmod +x /etc/initramfs-tools/hooks/decrypt_pkcs_hook ```
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```sudo update-initramfs -u```
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10. Test smartcard (without USB Key)
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11. Test LUKS Password (without Smartcard)
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