ENC(1SSL)							      OpenSSL								 ENC(1SSL)

NAME

       openssl-enc, enc - symmetric cipher routines

SYNOPSIS

       openssl enc -cipher [-help] [-ciphers] [-in filename] [-out filename] [-pass arg] [-e] [-d] [-a] [-base64] [-A] [-k password] [-kfile
       filename] [-K key] [-iv IV] [-S salt] [-salt] [-nosalt] [-z] [-md digest] [-iter count] [-pbkdf2] [-p] [-P] [-bufsize number] [-nopad]
       [-debug] [-none] [-rand file...]  [-writerand file] [-engine id]

       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

       -help
	   Print out a usage message.

       -ciphers
	   List 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 the PASS PHRASE ARGUMENTS section in openssl(1).

       -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 Superseded by the -pass argument.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	   Superseded by the -pass argument.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 default iteration count unless otherwise specified.

       -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.

       -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.

       -debug
	   Debug the BIOs used for I/O.

       -z  Compress or decompress clear text using zlib before encryption or after decryption. This option exists only if OpenSSL with compiled
	   with zlib or zlib-dynamic option.

       -none
	   Use NULL cipher (no encryption or decryption of input).

       -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 ; for MS-Windows, , for OpenVMS, and : for all others.

       [-writerand file]
	   Writes random data to the specified file upon exit.	This can be used with a subsequent -rand flag.

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 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 -engine options can only be used for hardware-assisted
       implementations of ciphers which are supported by the OpenSSL core or another engine specified in the configuration file.

       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 -salt option should ALWAYS be used if the key is being derived from a password unless you want compatibility with previous versions of
       OpenSSL.

       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.

       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.

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 of the enc command run with the -ciphers option (that is openssl enc -ciphers) produces a list of ciphers,
       supported by your version of OpenSSL, including ones provided by configured engines.

       The enc program does not support authenticated encryption modes like CCM and GCM, and will not support such modes in the future.  The enc
       interface by necessity must begin streaming output (e.g., to standard output when -out is not used) before the authentication tag could be
       validated, leading to the usage of 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 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 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, 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

	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

	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>

BUGS

       The -A option when used with large files doesn't work properly.

       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.

COPYRIGHT

       Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (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 <https://www.openssl.org/source/license.html>.

1.1.1a								    2018-12-18								 ENC(1SSL)