ubuntu:openssl:encrypt_a_file
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Table of Contents
Ubuntu - OpenSSL - Encrypt a file
Get a list of ciphers that OpenSSL supports
openssl enc -list
returns:
Supported ciphers: -aes-128-cbc -aes-128-cfb -aes-128-cfb1 -aes-128-cfb8 -aes-128-ctr -aes-128-ecb -aes-128-ofb -aes-192-cbc -aes-192-cfb -aes-192-cfb1 -aes-192-cfb8 -aes-192-ctr -aes-192-ecb -aes-192-ofb -aes-256-cbc -aes-256-cfb -aes-256-cfb1 -aes-256-cfb8 -aes-256-ctr -aes-256-ecb -aes-256-ofb -aes128 -aes128-wrap -aes192 -aes192-wrap -aes256 -aes256-wrap -aria-128-cbc -aria-128-cfb -aria-128-cfb1 -aria-128-cfb8 -aria-128-ctr -aria-128-ecb -aria-128-ofb -aria-192-cbc -aria-192-cfb -aria-192-cfb1 -aria-192-cfb8 -aria-192-ctr -aria-192-ecb -aria-192-ofb -aria-256-cbc -aria-256-cfb -aria-256-cfb1 -aria-256-cfb8 -aria-256-ctr -aria-256-ecb -aria-256-ofb -aria128 -aria192 -aria256 -bf -bf-cbc -bf-cfb -bf-ecb -bf-ofb -blowfish -camellia-128-cbc -camellia-128-cfb -camellia-128-cfb1 -camellia-128-cfb8 -camellia-128-ctr -camellia-128-ecb -camellia-128-ofb -camellia-192-cbc -camellia-192-cfb -camellia-192-cfb1 -camellia-192-cfb8 -camellia-192-ctr -camellia-192-ecb -camellia-192-ofb -camellia-256-cbc -camellia-256-cfb -camellia-256-cfb1 -camellia-256-cfb8 -camellia-256-ctr -camellia-256-ecb -camellia-256-ofb -camellia128 -camellia192 -camellia256 -cast -cast-cbc -cast5-cbc -cast5-cfb -cast5-ecb -cast5-ofb -chacha20 -des -des-cbc -des-cfb -des-cfb1 -des-cfb8 -des-ecb -des-ede -des-ede-cbc -des-ede-cfb -des-ede-ecb -des-ede-ofb -des-ede3 -des-ede3-cbc -des-ede3-cfb -des-ede3-cfb1 -des-ede3-cfb8 -des-ede3-ecb -des-ede3-ofb -des-ofb -des3 -des3-wrap -desx -desx-cbc -id-aes128-wrap -id-aes128-wrap-pad -id-aes192-wrap -id-aes192-wrap-pad -id-aes256-wrap -id-aes256-wrap-pad -id-smime-alg-CMS3DESwrap -rc2 -rc2-128 -rc2-40 -rc2-40-cbc -rc2-64 -rc2-64-cbc -rc2-cbc -rc2-cfb -rc2-ecb -rc2-ofb -rc4 -rc4-40 -seed -seed-cbc -seed-cfb -seed-ecb -seed-ofb -sm4 -sm4-cbc -sm4-cfb -sm4-ctr -sm4-ecb -sm4-ofb
Encode a file using aes256
openssl enc -aes256 -salt -in test1.txt -out test1.enc
NOTE: The -salt option should ALWAYS be used if the key is being derived from a password.
Without the -salt option it is possible to perform efficient dictionary attacks on the password and to attack stream cipher encrypted data.
The reason for this is that without the salt the same password always generates the same encryption key.
When the salt is being used the first eight bytes of the encrypted data are reserved for the salt: it is generated at random when encrypting a file and read from the encrypted file when it is decrypted.
Decode a file that was encrypted using aes256
openssl enc -aes256 -d -in test1.enc -out test2.txt
ubuntu/openssl/encrypt_a_file.1611937170.txt.gz · Last modified: 2021/01/29 16:19 by peter