Provided by: openssl_1.1.1-1ubuntu2_amd64 bug

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 Superseded by the -pass argument.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 Superseded by the -pass argument.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
        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

        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

        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

        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 triple DES in CBC mode using a prompted password:

        openssl des3 -salt -in file.txt -out file.des3

       Decrypt a file using a supplied password:

        openssl des3 -d -salt -in file.des3 -out file.txt -k mypassword

       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

       Base64 decode a file then decrypt it:

        openssl bf -d -salt -a -in file.bf -out file.txt

       Decrypt some data using a supplied 40 bit RC4 key:

        openssl rc4-40 -in file.rc4 -out file.txt -K 0102030405

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>.