SYNOPSIS
openssl enc
[-cipher]
[
openssl cipher ...
DESCRIPTION
The symmetric cipher commands allow data to be encrypted or decrypted using various block and stream ciphers using keys based on passwords or explicitly provided. Base64 encoding or decoding can also be performed either by itself or in addition to the encryption or decryption.
OPTIONS
- -cipher
-
The cipher to use.
-help -
Print out a usage message.
-list -
List all supported ciphers.
-ciphers -
Alias of
-list to display all supported ciphers. -in filename-
The input filename, standard input by default.
-out filename-
The output filename, standard output by default.
-pass arg-
The password source. For more information about the format of arg see openssl passphrase-options.
-e -
Encrypt the input data: this is the default.
-d -
Decrypt the input data.
-a -
Base64 process the data. This means that if encryption is taking place the data is base64 encoded after encryption. If decryption is set then the input data is base64 decoded before being decrypted.
-base64 -
Same as
-a -A -
If the
-a option is set then base64 process the data on one line. -k password-
The password to derive the key from. This is for compatibility with previous versions of OpenSSL. Superseded by the
-pass argument. -kfile filename-
Read the password to derive the key from the first line of filename. This is for compatibility with previous versions of OpenSSL. Superseded by the
-pass argument. -md digest-
Use the specified digest to create the key from the passphrase. The default algorithm is sha-256.
-iter count-
Use a given number of iterations on the password in deriving the encryption key. High values increase the time required to brute- force the resulting file. This option enables the use of PBKDF2 algorithm to derive the key.
-pbkdf2 -
Use PBKDF2 algorithm with a default iteration count of 10000 unless otherwise specified by the
-iter command line option. -saltlen -
Set the salt length to use when using the
-pbkdf2 option. For compatibility reasons, the default is 8 bytes. The maximum value is currently 16 bytes. If the-pbkdf2 option is not used, then this option is ignored and a fixed salt length of 8 is used. The salt length used when encrypting must also be used when decrypting. -nosalt -
Don't use a salt in the key derivation routines. This option SHOULD NOT be used except for test purposes or compatibility with ancient versions of OpenSSL.
-salt -
Use salt (randomly generated or provide with
-S option) when encrypting, this is the default. -S salt-
The actual salt to use: this must be represented as a string of hex digits. If this option is used while encrypting, the same exact value will be needed again during decryption. This salt may be truncated or zero padded to match the salt length (See
-saltlen ). -K key-
The actual key to use: this must be represented as a string comprised only of hex digits. If only the key is specified, the IV must additionally specified using the
-iv option. When both a key and a password are specified, the key given with the-K option will be used and the IV generated from the password will be taken. It does not make much sense to specify both key and password. -iv IV-
The actual IV to use: this must be represented as a string comprised only of hex digits. When only the key is specified using the
-K option, the IV must explicitly be defined. When a password is being specified using one of the other options, the IV is generated from this password. -p -
Print out the key and IV used.
-P -
Print out the key and IV used then immediately exit: don't do any encryption or decryption.
-bufsize number-
Set the buffer size for I/O.
-nopad -
Disable standard block padding.
-v -
Verbose print; display some statistics about I/O and buffer sizes.
-debug -
Debug the BIOs used for I/O.
-z -
Compress or decompress encrypted data using zlib after encryption or before decryption. This option exists only if OpenSSL was compiled with the zlib or zlib-dynamic option.
-none -
Use NULL cipher (no encryption or decryption of input).
-rand files-writerand file-
See Random State Options in openssl for details.
-provider name-provider-path path-propquery propq-
See Provider Options in openssl for details.
-engine id-
See Engine Options in openssl for details. This option is deprecated.
NOTES
The program can be called either as openssl cipher or openssl enc -cipher. The first form doesn't work with engine-provided ciphers, because this form is processed before the configuration file is read and any ENGINEs loaded. Use the openssl list command to get a list of supported ciphers.
Engines which provide entirely new encryption algorithms (such as the ccgost
engine which provides gost89 algorithm) should be configured in the
configuration file. Engines specified on the command line using
When the enc command lists supported ciphers, ciphers provided by engines, specified in the configuration files are listed too.
A password will be prompted for to derive the key and IV if necessary.
The
Without the
When the salt is generated at random (that means when encrypting using
a passphrase without explicit salt given using
Some of the ciphers do not have large keys and others have security implications if not used correctly. A beginner is advised to just use a strong block cipher, such as AES, in CBC mode.
All the block ciphers normally use PKCS#5 padding, also known as standard block padding. This allows a rudimentary integrity or password check to be performed. However since the chance of random data passing the test is better than 1 in 256 it isn't a very good test.
If padding is disabled then the input data must be a multiple of the cipher block length.
All RC2 ciphers have the same key and effective key length.
Blowfish and RC5 algorithms use a 128 bit key.
Please note that OpenSSL 3.0 changed the effect of the
When using OpenSSL 3.0 or later to decrypt data that was encrypted with
an explicit salt under OpenSSL 1.1.1 do not use the
SUPPORTED CIPHERS
Note that some of these ciphers can be disabled at compile time and
some are available only if an appropriate engine is configured in the
configuration file. The output when invoking this command with the
This command does not support authenticated encryption modes like CCM
and GCM, and will not support such modes in the future. This is due to
having to begin streaming output (e.g., to standard output when
When enc is used with key wrapping modes the input data cannot be
streamed, meaning it must be processed in a single pass. Consequently,
the input data size must be less than the buffer size (
base64 Base 64 bf-cbc Blowfish in CBC mode bf Alias for bf-cbc blowfish Alias for bf-cbc bf-cfb Blowfish in CFB mode bf-ecb Blowfish in ECB mode bf-ofb Blowfish in OFB mode cast-cbc CAST in CBC mode cast Alias for cast-cbc cast5-cbc CAST5 in CBC mode cast5-cfb CAST5 in CFB mode cast5-ecb CAST5 in ECB mode cast5-ofb CAST5 in OFB mode chacha20 ChaCha20 algorithm des-cbc DES in CBC mode des Alias for des-cbc des-cfb DES in CFB mode des-ofb DES in OFB mode des-ecb DES in ECB mode des-ede-cbc Two key triple DES EDE in CBC mode des-ede Two key triple DES EDE in ECB mode des-ede-cfb Two key triple DES EDE in CFB mode des-ede-ofb Two key triple DES EDE in OFB mode des-ede3-cbc Three key triple DES EDE in CBC mode des-ede3 Three key triple DES EDE in ECB mode des3 Alias for des-ede3-cbc des-ede3-cfb Three key triple DES EDE CFB mode des-ede3-ofb Three key triple DES EDE in OFB mode desx DESX algorithm. gost89 GOST 28147-89 in CFB mode (provided by ccgost engine) gost89-cnt GOST 28147-89 in CNT mode (provided by ccgost engine) idea-cbc IDEA algorithm in CBC mode idea same as idea-cbc idea-cfb IDEA in CFB mode idea-ecb IDEA in ECB mode idea-ofb IDEA in OFB mode rc2-cbc 128 bit RC2 in CBC mode rc2 Alias for rc2-cbc rc2-cfb 128 bit RC2 in CFB mode rc2-ecb 128 bit RC2 in ECB mode rc2-ofb 128 bit RC2 in OFB mode rc2-64-cbc 64 bit RC2 in CBC mode rc2-40-cbc 40 bit RC2 in CBC mode rc4 128 bit RC4 rc4-64 64 bit RC4 rc4-40 40 bit RC4 rc5-cbc RC5 cipher in CBC mode rc5 Alias for rc5-cbc rc5-cfb RC5 cipher in CFB mode rc5-ecb RC5 cipher in ECB mode rc5-ofb RC5 cipher in OFB mode seed-cbc SEED cipher in CBC mode seed Alias for seed-cbc seed-cfb SEED cipher in CFB mode seed-ecb SEED cipher in ECB mode seed-ofb SEED cipher in OFB mode sm4-cbc SM4 cipher in CBC mode sm4 Alias for sm4-cbc sm4-cfb SM4 cipher in CFB mode sm4-ctr SM4 cipher in CTR mode sm4-ecb SM4 cipher in ECB mode sm4-ofb SM4 cipher in OFB mode aes-[128|192|256]-cbc 128/192/256 bit AES in CBC mode aes[128|192|256] Alias for aes-[128|192|256]-cbc aes-[128|192|256]-cfb 128/192/256 bit AES in 128 bit CFB mode aes-[128|192|256]-cfb1 128/192/256 bit AES in 1 bit CFB mode aes-[128|192|256]-cfb8 128/192/256 bit AES in 8 bit CFB mode aes-[128|192|256]-ctr 128/192/256 bit AES in CTR mode aes-[128|192|256]-ecb 128/192/256 bit AES in ECB mode aes-[128|192|256]-ofb 128/192/256 bit AES in OFB mode aes-[128|192|256]-wrap key wrapping using 128/192/256 bit AES aes-[128|192|256]-wrap-pad key wrapping with padding using 128/192/256 bit AES aria-[128|192|256]-cbc 128/192/256 bit ARIA in CBC mode aria[128|192|256] Alias for aria-[128|192|256]-cbc aria-[128|192|256]-cfb 128/192/256 bit ARIA in 128 bit CFB mode aria-[128|192|256]-cfb1 128/192/256 bit ARIA in 1 bit CFB mode aria-[128|192|256]-cfb8 128/192/256 bit ARIA in 8 bit CFB mode aria-[128|192|256]-ctr 128/192/256 bit ARIA in CTR mode aria-[128|192|256]-ecb 128/192/256 bit ARIA in ECB mode aria-[128|192|256]-ofb 128/192/256 bit ARIA in OFB mode camellia-[128|192|256]-cbc 128/192/256 bit Camellia in CBC mode camellia[128|192|256] Alias for camellia-[128|192|256]-cbc camellia-[128|192|256]-cfb 128/192/256 bit Camellia in 128 bit CFB mode camellia-[128|192|256]-cfb1 128/192/256 bit Camellia in 1 bit CFB mode camellia-[128|192|256]-cfb8 128/192/256 bit Camellia in 8 bit CFB mode camellia-[128|192|256]-ctr 128/192/256 bit Camellia in CTR mode camellia-[128|192|256]-ecb 128/192/256 bit Camellia in ECB mode camellia-[128|192|256]-ofb 128/192/256 bit Camellia in OFB mode
EXAMPLES
Just base64 encode a binary file:
openssl base64 -in file.bin -out file.b64
Decode the same file
openssl base64 -d -in file.b64 -out file.bin
Encrypt a file using AES-128 using a prompted password and PBKDF2 key derivation:
openssl enc -aes128 -pbkdf2 -in file.txt -out file.aes128
Decrypt a file using a supplied password:
openssl enc -aes128 -pbkdf2 -d -in file.aes128 -out file.txt \
-pass pass:password
Encrypt a file then base64 encode it (so it can be sent via mail for example) using AES-256 in CTR mode and PBKDF2 key derivation:
openssl enc -aes-256-ctr -pbkdf2 -a -in file.txt -out file.aes256
Base64 decode a file then decrypt it using a password supplied in a file:
openssl enc -aes-256-ctr -pbkdf2 -d -a -in file.aes256 -out file.txt \
-pass file:passfile
AES key wrapping:
openssl enc -e -a -id-aes128-wrap-pad -K 000102030405060708090A0B0C0D0E0F -in file.bin
or
openssl aes128-wrap-pad -e -a -K 000102030405060708090A0B0C0D0E0F -in file.bin
BUGS
The
There should be an option to allow an iteration count to be included.
The enc program only supports a fixed number of algorithms with certain parameters. So if, for example, you want to use RC2 with a 76 bit key or RC4 with an 84 bit key you can't use this program.
HISTORY
The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0.
The
The
The
COPYRIGHT
Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or here: OpenSSL.
AVAILABILITY
PTC MKS Toolkit for System Administrators
PTC MKS Toolkit for Developers
PTC MKS Toolkit for Interoperability
PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition
PTC MKS Toolkit 10.5 Documentation Build 40.