=pod

=head1 NAME

openssl - OpenSSL command line tool

=head1 SYNOPSIS

B<openssl>
I<command>
[ I<command_opts> ... ]
[ I<command_args> ... ]

B<openssl>
B<list>
B<-standard-commands> |
B<-digest-commands> |
B<-cipher-commands> |
B<-cipher-algorithms> |
B<-digest-algorithms> |
B<-mac-algorithms> |
B<-public-key-algorithms>

B<openssl> B<no->I<XXX> [ I<arbitrary options> ]

=head1 DESCRIPTION

OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer (SSL
v2/v3) and Transport Layer Security (TLS v1) network protocols and related
cryptography standards required by them.

The B<openssl> program is a command line tool for using the various
cryptography functions of OpenSSL's B<crypto> library from the shell.
It can be used for

 o  Creation and management of private keys, public keys and parameters
 o  Public key cryptographic operations
 o  Creation of X.509 certificates, CSRs and CRLs
 o  Calculation of Message Digests and Message Authentication Codes
 o  Encryption and Decryption with Ciphers
 o  SSL/TLS Client and Server Tests
 o  Handling of S/MIME signed or encrypted mail
 o  Timestamp requests, generation and verification

=head1 COMMAND SUMMARY

The B<openssl> program provides a rich variety of sub-commands (I<command> in
the SYNOPSIS above), each of which often has a wealth of options and arguments
(I<command_opts> and I<command_args> in the SYNOPSIS).

Detailed documentation and use cases for most standard subcommands are available
(e.g., L<x509(1)> or L<openssl-x509(1)>).

Many commands use an external configuration file for some or all of their
arguments and have a B<-config> option to specify that file.
The environment variable B<OPENSSL_CONF> can be used to specify
the location of the file.
If the environment variable is not specified, then the file is named
F<openssl.cnf> in the default certificate storage area, whose value
depends on the configuration flags specified when the OpenSSL
was built.

The list options B<-standard-commands>, B<-digest-commands>,
and B<-cipher-commands> output a list (one entry per line) of the names
of all standard commands, message digest commands, or cipher commands,
respectively, that are available.

The list parameters B<-cipher-algorithms>, B<-digest-algorithms>,
and B<-mac-algorithms> list all cipher, message digest, and message
authentication code names, one entry per line. Aliases are listed as:

 from => to

The list parameter B<-public-key-algorithms> lists all supported public
key algorithms.

The command B<no->I<XXX> tests whether a command of the
specified name is available.  If no command named I<XXX> exists, it
returns 0 (success) and prints B<no->I<XXX>; otherwise it returns 1
and prints I<XXX>.  In both cases, the output goes to B<stdout> and
nothing is printed to B<stderr>.  Additional command line arguments
are always ignored.  Since for each cipher there is a command of the
same name, this provides an easy way for shell scripts to test for the
availability of ciphers in the B<openssl> program.  (B<no->I<XXX> is
not able to detect pseudo-commands such as B<quit>,
B<list>, or B<no->I<XXX> itself.)

=head2 Standard Sub-commands

=over 4

=item B<asn1parse>

Parse an ASN.1 sequence.

=item B<ca>

Certificate Authority (CA) Management.

=item B<ciphers>

Cipher Suite Description Determination.

=item B<cms>

CMS (Cryptographic Message Syntax) utility.

=item B<crl>

Certificate Revocation List (CRL) Management.

=item B<crl2pkcs7>

CRL to PKCS#7 Conversion.

=item B<dgst>

Message Digest calculation. MAC calculations are superseded by
L<openssl-mac(1)>.

=item B<dh>

Diffie-Hellman Parameter Management.
Obsoleted by L<openssl-dhparam(1)>.

=item B<dhparam>

Generation and Management of Diffie-Hellman Parameters. Superseded by
L<openssl-genpkey(1)> and L<openssl-pkeyparam(1)>.

=item B<dsa>

DSA Data Management.

=item B<dsaparam>

DSA Parameter Generation and Management. Superseded by
L<openssl-genpkey(1)> and L<openssl-pkeyparam(1)>.

=item B<ec>

EC (Elliptic curve) key processing.

=item B<ecparam>

EC parameter manipulation and generation.

=item B<enc>

Encoding with Ciphers.

=item B<engine>

Engine (loadable module) information and manipulation.

=item B<errstr>

Error Number to Error String Conversion.

=item B<gendh>

Generation of Diffie-Hellman Parameters.
Obsoleted by L<openssl-dhparam(1)>.

=item B<gendsa>

Generation of DSA Private Key from Parameters. Superseded by
L<openssl-genpkey(1)> and L<openssl-pkey(1)>.

=item B<genpkey>

Generation of Private Key or Parameters.

=item B<genrsa>

Generation of RSA Private Key. Superseded by L<openssl-genpkey(1)>.

=item B<info>

Display diverse information built into the OpenSSL libraries.

=item B<kdf>

Key Derivation Functions.

=item B<mac>

Message Authentication Code Calculation.

=item B<nseq>

Create or examine a Netscape certificate sequence.

=item B<ocsp>

Online Certificate Status Protocol utility.

=item B<passwd>

Generation of hashed passwords.

=item B<pkcs12>

PKCS#12 Data Management.

=item B<pkcs7>

PKCS#7 Data Management.

=item B<pkcs8>

PKCS#8 format private key conversion tool.

=item B<pkey>

Public and private key management.

=item B<pkeyparam>

Public key algorithm parameter management.

=item B<pkeyutl>

Public key algorithm cryptographic operation utility.

=item B<prime>

Compute prime numbers.

=item B<rand>

Generate pseudo-random bytes.

=item B<rehash>

Create symbolic links to certificate and CRL files named by the hash values.

=item B<req>

PKCS#10 X.509 Certificate Signing Request (CSR) Management.

=item B<rsa>

RSA key management.

=item B<rsautl>

RSA utility for signing, verification, encryption, and decryption. Superseded
by  L<openssl-pkeyutl(1)>.

=item B<s_client>

This implements a generic SSL/TLS client which can establish a transparent
connection to a remote server speaking SSL/TLS. It's intended for testing
purposes only and provides only rudimentary interface functionality but
internally uses mostly all functionality of the OpenSSL B<ssl> library.

=item B<s_server>

This implements a generic SSL/TLS server which accepts connections from remote
clients speaking SSL/TLS. It's intended for testing purposes only and provides
only rudimentary interface functionality but internally uses mostly all
functionality of the OpenSSL B<ssl> library.  It provides both an own command
line oriented protocol for testing SSL functions and a simple HTTP response
facility to emulate an SSL/TLS-aware webserver.

=item B<s_time>

SSL Connection Timer.

=item B<sess_id>

SSL Session Data Management.

=item B<smime>

S/MIME mail processing.

=item B<speed>

Algorithm Speed Measurement.

=item B<spkac>

SPKAC printing and generating utility.

=item B<srp>

Maintain SRP password file.

=item B<storeutl>

Utility to list and display certificates, keys, CRLs, etc.

=item B<ts>

Time Stamping Authority tool (client/server).

=item B<verify>

X.509 Certificate Verification.

=item B<version>

OpenSSL Version Information.

=item B<x509>

X.509 Certificate Data Management.

=back

=head2 Message Digest Commands

=over 4

=item B<blake2b512>

BLAKE2b-512 Digest

=item B<blake2s256>

BLAKE2s-256 Digest

=item B<md2>

MD2 Digest

=item B<md4>

MD4 Digest

=item B<md5>

MD5 Digest

=item B<mdc2>

MDC2 Digest

=item B<rmd160>

RMD-160 Digest

=item B<sha1>

SHA-1 Digest

=item B<sha224>

SHA-2 224 Digest

=item B<sha256>

SHA-2 256 Digest

=item B<sha384>

SHA-2 384 Digest

=item B<sha512>

SHA-2 512 Digest

=item B<sha3-224>

SHA-3 224 Digest

=item B<sha3-256>

SHA-3 256 Digest

=item B<sha3-384>

SHA-3 384 Digest

=item B<sha3-512>

SHA-3 512 Digest

=item B<shake128>

SHA-3 SHAKE128 Digest

=item B<shake256>

SHA-3 SHAKE256 Digest

=item B<sm3>

SM3 Digest

=back

=head2 Encoding and Cipher Commands

The following aliases provide convenient access to the most used encodings
and ciphers.

Depending on how OpenSSL was configured and built, not all ciphers listed
here may be present. See L<openssl-enc(1)> for more information and command
usage.

=over 4

=item B<aes128>, B<aes-128-cbc>, B<aes-128-cfb>, B<aes-128-ctr>, B<aes-128-ecb>, B<aes-128-ofb>

AES-128 Cipher

=item B<aes192>, B<aes-192-cbc>, B<aes-192-cfb>, B<aes-192-ctr>, B<aes-192-ecb>, B<aes-192-ofb>

AES-192 Cipher

=item B<aes256>, B<aes-256-cbc>, B<aes-256-cfb>, B<aes-256-ctr>, B<aes-256-ecb>, B<aes-256-ofb>

AES-256 Cipher

=item B<aria128>, B<aria-128-cbc>, B<aria-128-cfb>, B<aria-128-ctr>, B<aria-128-ecb>, B<aria-128-ofb>

Aria-128 Cipher

=item B<aria192>, B<aria-192-cbc>, B<aria-192-cfb>, B<aria-192-ctr>, B<aria-192-ecb>, B<aria-192-ofb>

Aria-192 Cipher

=item B<aria256>, B<aria-256-cbc>, B<aria-256-cfb>, B<aria-256-ctr>, B<aria-256-ecb>, B<aria-256-ofb>

Aria-256 Cipher

=item B<base64>

Base64 Encoding

=item B<bf>, B<bf-cbc>, B<bf-cfb>, B<bf-ecb>, B<bf-ofb>

Blowfish Cipher

=item B<camellia128>, B<camellia-128-cbc>, B<camellia-128-cfb>, B<camellia-128-ctr>, B<camellia-128-ecb>, B<camellia-128-ofb>

Camellia-128 Cipher

=item B<camellia192>, B<camellia-192-cbc>, B<camellia-192-cfb>, B<camellia-192-ctr>, B<camellia-192-ecb>, B<camellia-192-ofb>

Camellia-192 Cipher

=item B<camellia256>, B<camellia-256-cbc>, B<camellia-256-cfb>, B<camellia-256-ctr>, B<camellia-256-ecb>, B<camellia-256-ofb>

Camellia-256 Cipher

=item B<cast>, B<cast-cbc>

CAST Cipher

=item B<cast5-cbc>, B<cast5-cfb>, B<cast5-ecb>, B<cast5-ofb>

CAST5 Cipher

=item B<chacha20>

Chacha20 Cipher

=item B<des>, B<des-cbc>, B<des-cfb>, B<des-ecb>, B<des-ede>, B<des-ede-cbc>, B<des-ede-cfb>, B<des-ede-ofb>, B<des-ofb>

DES Cipher

=item B<des3>, B<desx>, B<des-ede3>, B<des-ede3-cbc>, B<des-ede3-cfb>, B<des-ede3-ofb>

Triple-DES Cipher

=item B<idea>, B<idea-cbc>, B<idea-cfb>, B<idea-ecb>, B<idea-ofb>

IDEA Cipher

=item B<rc2>, B<rc2-cbc>, B<rc2-cfb>, B<rc2-ecb>, B<rc2-ofb>

RC2 Cipher

=item B<rc4>

RC4 Cipher

=item B<rc5>, B<rc5-cbc>, B<rc5-cfb>, B<rc5-ecb>, B<rc5-ofb>

RC5 Cipher

=item B<seed>, B<seed-cbc>, B<seed-cfb>, B<seed-ecb>, B<seed-ofb>

SEED Cipher

=item B<sm4>, B<sm4-cbc>, B<sm4-cfb>, B<sm4-ctr>, B<sm4-ecb>, B<sm4-ofb>

SM4 Cipher

=back

=head1 OPTIONS

Details of which options are available depend on the specific command.
This section describes some common options with common behavior.

=head2 Common Options

=over 4

=item B<-help>

Provides a terse summary of all options.
If an option takes an argument, the "type" of argument is also given.

=item B<-->

This terminates the list of options. It is mostly useful if any filename
parameters start with a minus sign:

 openssl verify [flags...] -- -cert1.pem...

=back

=head2 Format Options

Several OpenSSL commands can take input or generate output in a variety
of formats. The list of acceptable formats, and the default, is
described in each command documentation.  The list of formats is
described below. Both uppercase and lowercase are accepted.

=over 4

=item B<DER>

A binary format, encoded or parsed according to Distinguished Encoding Rules
(DER) of the ASN.1 data language.

=item B<ENGINE>

Used to specify that the cryptographic material is in an OpenSSL B<engine>.
An engine must be configured or specified using the B<-engine> option.
In addition, the B<-input> flag can be used to name a specific object in
the engine.
A password, such as the B<-passin> flag often must be specified as well.

=item B<P12>

A DER-encoded file containing a PKCS#12 object.
It might be necessary to provide a decryption password to retrieve
the private key.

=item B<PEM>

A text format defined in IETF RFC 1421 and IETF RFC 7468. Briefly, this is
a block of base-64 encoding (defined in IETF RFC 4648), with specific
lines used to mark the start and end:

 Text before the BEGIN line is ignored.
 ----- BEGIN object-type -----
 OT43gQKBgQC/2OHZoko6iRlNOAQ/tMVFNq7fL81GivoQ9F1U0Qr+DH3ZfaH8eIkX
 xT0ToMPJUzWAn8pZv0snA0um6SIgvkCuxO84OkANCVbttzXImIsL7pFzfcwV/ERK
 UM6j0ZuSMFOCr/lGPAoOQU0fskidGEHi1/kW+suSr28TqsyYZpwBDQ==
 ----- END object-type -----
 Text after the END line is also ignored

The I<object-type> must match the type of object that is expected.
For example a C<BEGIN X509 CERTIFICATE> will not match if the command
is trying to read a private key. The types supported include:

 ANY PRIVATE KEY
 CERTIFICATE
 CERTIFICATE REQUEST
 CMS
 DH PARAMETERS
 DSA PARAMETERS
 DSA PUBLIC KEY
 EC PARAMETERS
 EC PRIVATE KEY
 ECDSA PUBLIC KEY
 ENCRYPTED PRIVATE KEY
 PARAMETERS
 PKCS #7 SIGNED DATA
 PKCS7
 PRIVATE KEY
 PUBLIC KEY
 RSA PRIVATE KEY
 SSL SESSION PARAMETERS
 TRUSTED CERTIFICATE
 X509 CRL
 X9.42 DH PARAMETERS

The following legacy I<object-type>'s are also supported for compatibility
with earlier releases:

 DSA PRIVATE KEY
 NEW CERTIFICATE REQUEST
 RSA PUBLIC KEY
 X509 CERTIFICATE

=item B<SMIME>

An S/MIME object as described in IETF RFC 8551.
Earlier versions were known as CMS and are compatible.
Note that the parsing is simple and might fail to parse some legal data.

=back

The options to specify the format are as follows. Refer to the individual
manpage to see which options are accepted.

=over 4

=item B<-inform> I<format>, B<-outform> I<format>

The format of the input or output streams.

=item B<-keyform> I<format>

Format of a private key input source.

=item B<-CRLform> I<format>

Format of a CRL input source.

=back

=head2 Pass Phrase Options

Several commands accept password arguments, typically using B<-passin>
and B<-passout> for input and output passwords respectively. These allow
the password to be obtained from a variety of sources. Both of these
options take a single argument whose format is described below. If no
password argument is given and a password is required then the user is
prompted to enter one: this will typically be read from the current
terminal with echoing turned off.

Note that character encoding may be relevant, please see
L<passphrase-encoding(7)>.

=over 4

=item B<pass:>I<password>

The actual password is I<password>. Since the password is visible
to utilities (like 'ps' under Unix) this form should only be used
where security is not important.

=item B<env:>I<var>

Obtain the password from the environment variable I<var>. Since
the environment of other processes is visible on certain platforms
(e.g. ps under certain Unix OSes) this option should be used with caution.

=item B<file:>I<pathname>

The first line of I<pathname> is the password. If the same I<pathname>
argument is supplied to B<-passin> and B<-passout> arguments then the first
line will be used for the input password and the next line for the output
password. I<pathname> need not refer to a regular file: it could for example
refer to a device or named pipe.

=item B<fd:>I<number>

Read the password from the file descriptor I<number>. This can be used to
send the data via a pipe for example.

=item B<stdin>

Read the password from standard input.

=back

=head2 Trusted Certificate Options

Part of validating a certificate includes verifying that the chain of CA's
can be traced up to an existing trusted root.  The following options specify
how to list the trusted roots, also known as trust anchors.  A collection
of trusted roots is called a I<trust store>.

Note that OpenSSL does not provide a default set of trust anchors.  Many
Linux distributions include a system default and configure OpenSSL to point
to that.  Mozilla maintains an influential trust store that can be found at
L<https://www.mozilla.org/en-US/about/governance/policies/security-group/certs/>.

=over 4

=item B<-CAfile> I<file>

Load the specified file which contains one or more PEM-format certificates
of CA's that are trusted.

=item B<-no-CAfile>

Do not load the default file of trusted certificates.

=item B<-CApath> I<dir>

Use the specified directory as a list of trust certificates. That is,
files should be named with the hash of the X.509 SubjectName of each
certificate. This is so that the library can extract the IssuerName,
hash it, and directly lookup the file to get the issuer certificate.
See L<openssl-rehash(1)> for information on creating this type of directory.

=item B<-no-CApath>

Do not use the default directory of trusted certificates.

=back

=head2 Random State Options

Prior to OpenSSL 3.0, it was common for applications to store information
about the state of the random-number generator in a file that was loaded
at startup and rewritten upon exit. On modern operating systems, this is
generally no longer necessary as OpenSSL will seed itself from the
appropriate CPU flags, device files, and so on. These flags are still
supported for special platforms or circumstances that might require them.

It is generally an error to use the same seed file more than once and
every use of B<-rand> should be paired with B<-writerand>.

=over 4

=item B<-rand> I<files>

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 C<;> for MS-Windows, C<,> for OpenVMS, and C<:> for
all others. Another way to specify multiple files is to repeat this flag
with different filenames.

=item B<-writerand> I<file>

Writes the seed data to the specified I<file> upon exit.
This file can be used in a subsequent command invocation.

=back

=head2 Extended Verification Options

Sometimes there may be more than one certificate chain leading to an
end-entity certificate.
This usually happens when a root or intermediate CA signs a certificate
for another a CA in other organization.
Another reason is when a CA might have intermediates that use two different
signature formats, such as a SHA-1 and a SHA-256 digest.

The following options can be used to provide data that will allow the
OpenSSL command to generate an alternative chain.

=over 4

=item B<-xchain_build>

Specify whether the application should build the certificate chain to be
provided to the server for the extra certificates via the B<-xkey>,
B<-xcert>, and B<-xchain> options.

=item B<-xkey> I<infile>, B<-xcert> I<infile>, B<-xchain>

Specify an extra certificate, private key and certificate chain. These behave
in the same manner as the B<-cert>, B<-key> and B<-cert_chain> options.  When
specified, the callback returning the first valid chain will be in use by the
client.

=item B<-xcertform> B<DER>|B<PEM>, B<-xkeyform> B<DER>|B<PEM>

The input format for the extra certifcate and key, respectively.
See L<openssl(1)/Format Options> for details.

=back

=head1 ENVIRONMENT

=over 4

=item B<OPENSSL_TRACE=>I<name>[,...]

Enable tracing output of OpenSSL library, by name.
This output will only make sense if you know OpenSSL internals well.
Also, it might not give you any output at all, depending on how
OpenSSL was built.

The value is a comma separated list of names, with the following
available:

=over 4

=item B<TRACE>

The tracing functionality.

=item B<TLS>

General SSL/TLS.

=item B<TLS_CIPHER>

SSL/TLS cipher.

=item B<ENGINE_CONF>

ENGINE configuration.

=item B<ENGINE_TABLE>

The function that is used by RSA, DSA (etc) code to select registered
ENGINEs, cache defaults and functional references (etc), will generate
debugging summaries.

=item B<ENGINE_REF_COUNT>

Reference counts in the ENGINE structure will be monitored with a line
of generated for each change.

=item B<PKCS5V2>

PKCS#5 v2 keygen.

=item B<PKCS12_KEYGEN>

PKCS#12 key generation.

=item B<PKCS12_DECRYPT>

PKCS#12 decryption.

=item B<X509V3_POLICY>

Generates the complete policy tree at various point during X.509 v3
policy evaluation.

=item B<BN_CTX>

BIGNUM context.

=back

=back

=head1 SEE ALSO

L<openssl-asn1parse(1)>,
L<openssl-ca(1)>,
L<openssl-ciphers(1)>,
L<openssl-cms(1)>,
L<openssl-crl(1)>,
L<openssl-crl2pkcs7(1)>,
L<openssl-dgst(1)>,
L<openssl-dhparam(1)>,
L<openssl-dsa(1)>,
L<openssl-dsaparam(1)>,
L<openssl-ec(1)>,
L<openssl-ecparam(1)>,
L<openssl-enc(1)>,
L<openssl-engine(1)>,
L<openssl-errstr(1)>,
L<openssl-gendsa(1)>,
L<openssl-genpkey(1)>,
L<openssl-genrsa(1)>,
L<openssl-kdf(1)>,
L<openssl-mac(1)>,
L<openssl-nseq(1)>,
L<openssl-ocsp(1)>,
L<openssl-passwd(1)>,
L<openssl-pkcs12(1)>,
L<openssl-pkcs7(1)>,
L<openssl-pkcs8(1)>,
L<openssl-pkey(1)>,
L<openssl-pkeyparam(1)>,
L<openssl-pkeyutl(1)>,
L<openssl-prime(1)>,
L<openssl-rand(1)>,
L<openssl-rehash(1)>,
L<openssl-req(1)>,
L<openssl-rsa(1)>,
L<openssl-rsautl(1)>,
L<openssl-s_client(1)>,
L<openssl-s_server(1)>,
L<openssl-s_time(1)>,
L<openssl-sess_id(1)>,
L<openssl-smime(1)>,
L<openssl-speed(1)>,
L<openssl-spkac(1)>,
L<openssl-srp(1)>,
L<openssl-storeutl(1)>,
L<openssl-ts(1)>,
L<openssl-verify(1)>,
L<openssl-version(1)>,
L<openssl-x509(1)>,
L<config(5)>,
L<crypto(7)>,
L<ssl(7)>,
L<x509v3_config(5)>


=head1 HISTORY

The B<list> -I<XXX>B<-algorithms> options were added in OpenSSL 1.0.0;
For notes on the availability of other commands, see their individual
manual pages.

=head1 COPYRIGHT

Copyright 2000-2019 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 at
L<https://www.openssl.org/source/license.html>.

=cut
