=head1 NAME
+openssl-enc,
enc - symmetric cipher routines
=head1 SYNOPSIS
-B<openssl enc -ciphername>
+B<openssl enc -I<cipher>>
[B<-help>]
[B<-ciphers>]
[B<-in filename>]
[B<-pass arg>]
[B<-e>]
[B<-d>]
-[B<-a/-base64>]
+[B<-a>]
+[B<-base64>]
[B<-A>]
[B<-k password>]
[B<-kfile filename>]
[B<-nosalt>]
[B<-z>]
[B<-md digest>]
+[B<-iter count>]
+[B<-pbkdf2>]
[B<-p>]
[B<-P>]
[B<-bufsize number>]
[B<-nopad>]
[B<-debug>]
[B<-none>]
+[B<-rand file...>]
+[B<-writerand file>]
[B<-engine id>]
+B<openssl> I<[cipher]> [B<...>]
+
=head1 DESCRIPTION
The symmetric cipher commands allow data to be encrypted or decrypted
=item B<-in filename>
-the input filename, standard input by default.
+The input filename, standard input by default.
=item B<-out filename>
-the output filename, standard output by default.
+The output filename, standard output by default.
=item B<-pass arg>
-
the password source. For more information about the format of B<arg>
+
The password source. For more information about the format of B<arg>
see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
=item B<-e>
-encrypt the input data: this is the default.
+Encrypt the input data: this is the default.
=item B<-d>
-decrypt the input data.
+Decrypt the input data.
=item B<-a>
-base64 process the data. This means that if encryption is taking place
+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.
=item B<-base64>
-same as B<-a>
+Same as B<-a>
=item B<-A>
-if the B<-a> option is set then base64 process the data on one line.
+If the B<-a> option is set then base64 process the data on one line.
=item B<-k password>
-the password to derive the key from. This is for compatibility with previous
+The password to derive the key from. This is for compatibility with previous
versions of OpenSSL. Superseded by the B<-pass> argument.
=item B<-kfile filename>
-read the password to derive the key from the first line of B<filename>.
+Read the password to derive the key from the first line of B<filename>.
This is for compatibility with previous versions of OpenSSL. Superseded by
the B<-pass> argument.
Use the specified digest to create the key from the passphrase.
The default algorithm is sha-256.
+=item B<-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.
+
+=item B<-pbkdf2>
+
+Use PBKDF2 algorithm with default iteration count unless otherwise specified.
+
=item B<-nosalt>
-don't use a salt in the key derivation routines. This option B<SHOULD NOT> be
+Don't use a salt in the key derivation routines. This option B<SHOULD NOT> be
used except for test purposes or compatibility with ancient versions of
OpenSSL.
=item B<-salt>
-use salt (randomly generated or provide with B<-S> option) when
-encrypting (this is the default).
+Use salt (randomly generated or provide with B<-S> option) when
+encrypting, this is the default.
=item B<-S salt>
-the actual salt to use: this must be represented as a string of hex digits.
+The actual salt to use: this must be represented as a string of hex digits.
=item B<-K key>
-the actual key to use: this must be represented as a string comprised only
+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 B<-iv> option. When both a key and a password are specified, the
key given with the B<-K> option will be used and the IV generated from the
-password will be taken. It probably does not make much sense to specify
-both key and password.
+password will be taken. It does not make much sense to specify both key
+and password.
=item B<-iv IV>
-the actual IV to use: this must be represented as a string comprised only
+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 B<-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.
=item B<-p>
-print out the key and IV used.
+Print out the key and IV used.
=item B<-P>
-print out the key and IV used then immediately exit: don't do any encryption
+Print out the key and IV used then immediately exit: don't do any encryption
or decryption.
=item B<-bufsize number>
-set the buffer size for I/O
+Set the buffer size for I/O.
=item B<-nopad>
-disable standard block padding
+Disable standard block padding.
=item B<-debug>
-debug the BIOs used for I/O.
+Debug the BIOs used for I/O.
=item B<-z>
Use NULL cipher (no encryption or decryption of input).
+=item B<-rand file...>
+
+A file or files containing random data used to seed the random number
+generator.
+Multiple files can be specified separated by an OS-dependent character.
+The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
+all others.
+
+=item [B<-writerand file>]
+
+Writes random data to the specified I<file> upon exit.
+This can be used with a subsequent B<-rand> flag.
+
=back
=head1 NOTES
-The program can be called either as B<openssl ciphername> or
-B<openssl enc -ciphername>. But the first form doesn't work with
+The program can be called either as B<openssl cipher> or
+B<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 B<list> command to get a list of supported ciphers.
-Engines which provide entirely new encryption algorithms (such as ccgost
+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 in the command line using -engine
+configuration file. Engines specified on the command line using -engine
options can only be used for hardware-assisted implementations of
-ciphers, which are supported by OpenSSL core or other engine, specified
+ciphers which are supported by the OpenSSL core or another engine specified
in the configuration file.
-When enc command lists supported ciphers, ciphers provided by engines,
+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.
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 in CBC mode such as bf or des3.
+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.
+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.
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 of the B<enc> command run with
-unsupported options (for example B<openssl enc -help>) includes a
+the B<-ciphers> option (that is B<openssl enc -ciphers>) produces a
list of ciphers, supported by your version of OpenSSL, including
ones provided by configured engines.
The B<enc> program does not support authenticated encryption modes
-like CCM and GCM. The utility does not store or retrieve the
-authentication tag.
+like CCM and GCM, and will not support such modes in the future.
+The B<enc> interface by necessity must begin streaming output (e.g.,
+to standard output when B<-out> is not used) before the authentication
+tag could be validated, leading to the usage of B<enc> in pipelines
+that begin processing untrusted data and are not capable of rolling
+back upon authentication failure. The AEAD modes currently in common
+use also suffer from catastrophic failure of confidentiality and/or
+integrity upon reuse of key/iv/nonce, and since B<enc> places the
+entire burden of key/iv/nonce management upon the user, the risk of
+exposing AEAD modes is too great to allow. These key/iv/nonce
+management issues also affect other modes currently exposed in B<enc>,
+but the failure modes are less extreme in these cases, and the
+functionality cannot be removed with a stable release branch.
+For bulk encryption of data, whether using authenticated encryption
+modes or other modes, L<cms(1)> is recommended, as it provides a
+standard data format and performs the needed key/iv/nonce management.
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
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 CBC mode
+ des-cfb DES in CFB mode
des-ofb DES in OFB mode
des-ecb DES in ECB 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
+ 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
+
=head1 EXAMPLES
Just base64 encode a binary file:
openssl base64 -d -in file.b64 -out file.bin
-Encrypt a file using triple DES in CBC mode using a prompted password:
+Encrypt a file using AES-128 using a prompted password
+and PBKDF2 key derivation:
- openssl des3 -salt -in file.txt -out file.des3
+ openssl enc -aes128 -pbkdf2 -in file.txt -out file.aes128
Decrypt a file using a supplied password:
- openssl des3 -d -salt -in file.des3 -out file.txt -k mypassword
+ 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 Blowfish in CBC mode:
-
- openssl bf -a -salt -in file.txt -out file.bf
+using AES-256 in CTR mode and PBKDF2 key derivation:
-Base64 decode a file then decrypt it:
+ openssl enc -aes-256-ctr -pbkdf2 -a -in file.txt -out file.aes256
- openssl bf -d -salt -a -in file.bf -out file.txt
+Base64 decode a file then decrypt it using a password supplied in a file:
-Decrypt some data using a supplied 40 bit RC4 key:
-
- openssl rc4-40 -in file.rc4 -out file.txt -K 0102030405
+ openssl enc -aes-256-ctr -pbkdf2 -d -a -in file.aes256 -out file.txt \
+ -pass file:<passfile>
=head1 BUGS
The B<-A> option when used with large files doesn't work properly.
-There should be an option to allow an iteration count to be included.
-
The B<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.
=head1 HISTORY
-The default digest was changed from MD5 to SHA256 in Openssl 1.1.
+The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0.
=head1 COPYRIGHT
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
-Licensed under the OpenSSL license (the "License"). You may not use
+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 at
L<https://www.openssl.org/source/license.html>.
projects / openssl.git / blobdiff