openssl -- OpenSSL command line program

SYNOPSIS

openssl command [options] [parameters]

openssl no-XXX [options]

openssl [-help] [-version]

DESCRIPTION

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

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

Creation and management of private keys, public keys and parameters

Public key cryptographic operations

Creation of X.509 certificates CSRs and CRLs

Calculation of Message Digests and Message Authentication Codes

Encryption and Decryption with Ciphers

SSL/TLS Client and Server Tests

Handling of S/MIME signed or encrypted mail

Timestamp requests, generation and verification

COMMAND SUMMARY

The openssl program provides a rich variety of commands (command in the SYNOPSIS) each of which can have many options and arguments (command_opts and command_args in the SYNOPSIS).

Detailed documentation and use cases for most standard subcommands are available (e.g., x509 or openssl_x509). The subcommand openssl list may be used to list subcommands.

The command no-XXX tests whether a command of the specified name is available. If no command named XXX exists, it returns 0 (success) and prints no-XXX; otherwise it returns 1 and prints XXX. In both cases, the output goes to stdout and nothing is printed to 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 openssl program. (no-XXX is not able to detect pseudo-commands such as quit, list, or no-XXX itself.)

Configuration Option

Many commands use an external configuration file for some or all of their arguments and have a -config option to specify that file. The default name of the file is openssl.cnf in the default certificate storage area, which can be determined from the openssl version command using the -d or -a option. The environment variable OPENSSL_CONF can be used to specify a different file location or to disable loading a configuration (using the empty string).

Among others, the configuration file can be used to load modules and to specify parameters for generating certificates and random numbers. See openssl config for details.

Standard Commands

asn1parse: Parse an ASN.1 sequence.
ca: Certificate Authority (CA) Management.
ciphers: Cipher Suite Description Determination.
cms: CMS (Cryptographic Message Syntax) command.
crl: Certificate Revocation List (CRL) Management.
crl2pkcs7: CRL to PKCS#7 Conversion.
dgst: Message Digest calculation. MAC calculations are superseded by openssl-mac.
dhparam: Generation and Management of Diffie-Hellman Parameters. Superseded by openssl-genpkey and openssl pkeyparam.
dsa: DSA Data Management.
dsaparam: DSA Parameter Generation and Management. Superseded by openssl genpkey and openssl pkeyparam.
ec: EC (Elliptic curve) key processing.
ecparam: EC parameter manipulation and generation.
enc: Encryption, decryption, and encoding.
engine: Engine (loadable module) information and manipulation.
errstr: Error Number to Error String Conversion.
fipsinstall: FIPS configuration installation.
gendsa: Generation of DSA Private Key from Parameters. Superseded by openssl genpkey and openssl pkey.
genpkey: Generation of Private Key or Parameters.
genrsa: Generation of RSA Private Key. Superseded by openssl genpkey.
help: Display information about a command's options.
info: Display diverse information built into the OpenSSL libraries.
kdf: Key Derivation Functions.
list: List algorithms and features.
mac: Message Authentication Code Calculation.
nseq: Create or examine a Netscape certificate sequence.
ocsp: Online Certificate Status Protocol command.
passwd: Generation of hashed passwords.
pkcs12: PKCS#12 Data Management.
pkcs7: PKCS#7 Data Management.
pkcs8: PKCS#8 format private key conversion command.
pkey: Public and private key management.
pkeyparam: Public key algorithm parameter management.
pkeyutl: Public key algorithm cryptographic operation command.
prime: Compute prime numbers.
rand: Generate pseudo-random bytes.
rehash: Create symbolic links to certificate and CRL files named by the hash values.
req: PKCS#10 X.509 Certificate Signing Request (CSR) Management.
rsa: RSA key management.
rsautl: RSA command for signing, verification, encryption, and decryption. Superseded by openssl pkeyutl.
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 ssl library.
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 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.
s_time: SSL Connection Timer.
sess_id: SSL Session Data Management.
smime: S/MIME mail processing.
speed: Algorithm Speed Measurement.
spkac: SPKAC printing and generating command.
srp: Maintain SRP password file. This command is deprecated.
storeutl: Command to list and display certificates, keys, CRLs, etc.
ts: Time Stamping Authority command.
verify: X.509 Certificate Verification. See also the openssl-verification-options manual page.
version: OpenSSL Version Information.
x509: X.509 Certificate Data Management.

Message Digest Commands

blake2b512: BLAKE2b-512 Digest
blake2s256: BLAKE2s-256 Digest
md2: MD2 Digest
md4: MD4 Digest
md5: MD5 Digest
mdc2: MDC2 Digest
rmd160: RMD-160 Digest
sha1: SHA-1 Digest
sha224: SHA-2 224 Digest
sha256: SHA-2 256 Digest
sha384: SHA-2 384 Digest
sha512: SHA-2 512 Digest
sha3-224: SHA-3 224 Digest
sha3-256: SHA-3 256 Digest
sha3-384: SHA-3 384 Digest
sha3-512: SHA-3 512 Digest
keccak-224: KECCAK 224 Digest
keccak-256: KECCAK 256 Digest
keccak-384: KECCAK 384 Digest
keccak-512: KECCAK 512 Digest
shake128: SHA-3 SHAKE128 Digest
shake256: SHA-3 SHAKE256 Digest
sm3: SM3 Digest

Encryption, Decryption and Encoding 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 openssl enc for more information and command usage.

aes128
aes-128-cbc
aes-128-cfb
aes-128-ctr
aes-128-ecb
aes-128-ofb: AES-128 Cipher
aes192
aes-192-cbc
aes-192-cfb
aes-192-ctr
aes-192-ecb
aes-192-ofb: AES-192 Cipher
aes256
aes-256-cbc
aes-256-cfb
aes-256-ctr
aes-256-ecb
aes-256-ofb: AES-256 Cipher
aria128
aria-128-cbc
aria-128-cfb
aria-128-ctr
aria-128-ecb
aria-128-ofb: Aria-128 Cipher
aria192
aria-192-cbc
aria-192-cfb
aria-192-ctr
aria-192-ecb
aria-192-ofb: Aria-192 Cipher
aria256
aria-256-cbc
aria-256-cfb
aria-256-ctr
aria-256-ecb
aria-256-ofb: Aria-256 Cipher
base64: Base64 Encoding
bf
bf-cbc
bf-cfb
bf-ecb
bf-ofb: Blowfish Cipher
camellia128
camellia-128-cbc
camellia-128-cfb
camellia-128-ctr
camellia-128-ecb
camellia-128-ofb: Camellia-128 Cipher
camellia192
camellia-192-cbc
camellia-192-cfb
camellia-192-ctr
camellia-192-ecb
camellia-192-ofb: Camellia-192 Cipher
camellia256
camellia-256-cbc
camellia-256-cfb
camellia-256-ctr
camellia-256-ecb
camellia-256-ofb: Camellia-256 Cipher
cast
cast-cbc: CAST Cipher
cast5-cbc
cast5-cfb
cast5-ecb
cast5-ofb: CAST5 Cipher
chacha20: Chacha20 Cipher
des
des-cbc
des-cfb
des-ecb
des-ede
des-ede-cbc
des-ede-cfb
des-ede-ofb
des-ofb: DES Cipher
des3
desx
des-ede3
des-ede3-cbc
des-ede3-cfb
des-ede3-ofb: Triple-DES Cipher
idea
idea-cbc
idea-cfb
idea-ecb
idea-ofb: IDEA Cipher
rc2
rc2-cbc
rc2-cfb
rc2-ecb
rc2-ofb: RC2 Cipher
rc4: RC4 Cipher
rc5
rc5-cbc
rc5-cfb
rc5-ecb
rc5-ofb: RC5 Cipher
seed
seed-cbc
seed-cfb
seed-ecb
seed-ofb: SEED Cipher
sm4
sm4-cbc
sm4-cfb
sm4-ctr
sm4-ecb
sm4-ofb: SM4 Cipher

OPTIONS

Program Options

-help: Provides a terse summary of all options. For more detailed information, each command supports a -help option. Accepts --help as well.
-version: Provides a terse summary of the openssl program version. For more detailed information see openssl-version. Accepts --version as well.

Common Options

-help: Provides a terse summary of all options.

Pass Phrase Options

See the openssl passphrase-options manual page.

Random State Options

Prior to OpenSSL 1.1.1, 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 a trusted entropy source provided by the operating system. 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 -rand should be paired with -writerand.

-rand 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 ";" for MS-Windows, "," for OpenVMS, and ":" for all others. Another way to specify multiple files is to repeat this flag with different filenames.
-writerand file: Writes the seed data to the specified file upon exit. This file can be used in a subsequent command invocation.

Certificate Verification Options

See the openssl verification-options manual page.

Name Format Options

See the openssl namedisplay-options manual page.

TLS Version Options

Several commands use SSL, TLS, or DTLS. By default, the commands use TLS and clients will offer the lowest and highest protocol version they support, and servers will pick the highest version that the client offers that is also supported by the server.

The options below can be used to limit which protocol versions are used, and whether TCP (SSL and TLS) or UDP (DTLS) is used. Note that not all protocols and flags may be available, depending on how OpenSSL was built.

-ssl3
-tls1
-tls1_1
-tls1_2
-tls1_3
-no_ssl3
-no_tls1
-no_tls1_1
-no_tls1_2
-no_tls1_3: These options require or disable the use of the specified SSL or TLS protocols. When a specific TLS version is required, only that version will be offered or accepted. Only one specific protocol can be given and it cannot be combined with any of the no_ options. The no_* options do not work with s_time and ciphers commands but work with s_client and s_server commands.
-dtls
-dtls1
-dtls1_2: These options specify to use DTLS instead of TLS. With -dtls, clients will negotiate any supported DTLS protocol version. Use the -dtls1 or -dtls1_2 options to support only DTLS1.0 or DTLS1.2, respectively.

Engine Options

-engine id

Load the engine identified by id and use all the methods it implements (algorithms, key storage, etc.), unless specified otherwise in the command-specific documentation or it is configured to do so, as described in "Engine Configuration" in openssl config.

The engine will be used for key ids specified with -key and similar options when an option like -keyform engine is given.

A special case is the "loader_attic" engine, which is meant just for internal OpenSSL testing purposes and supports loading keys, parameters, certificates, and CRLs from files. When this engine is used, files with such credentials are read via this engine. Using the "file:" schema is optional; a plain file (path) name will do.

Options specifying keys, like -key and similar, can use the generic OpenSSL engine key loading URI scheme "org.openssl.engine:" to retrieve private keys and public keys. The URI syntax is as follows, in simplified form:

org.openssl.engine:{engineid}:{keyid}

Where "{engineid}" is the identity/name of the engine, and "{keyid}" is a key identifier that's acceptable by that engine. For example, when using an engine that interfaces against a PKCS#11 implementation, the generic key URI would be something like this (this happens to be an example for the PKCS#11 engine that's part of OpenSC):

-key org.openssl.engine:pkcs11:label_some-private-key

As a third possibility, for engines and providers that have implemented their own OSSL_STORE_LOADER(3), "org.openssl.engine:" should not be necassary. For a PKCS#11 implementation that has implemented such a loader, the PKCS#11 URI as defined in RFC 7512 should be possible to use directly:

-key pkcs11:object=some-private-key;pin-value=1234

Provider Options

-provider name: Load and initialize the provider identified by name. The name can be also a path to the provider module. In that case the provider name will be the specified path and not just the provider module name. Interpretation of relative paths is platform specific. The configured "MODULESDIR" path, OPENSSL_MODULES environment variable, or the path specified by -provider-path is prepended to relative paths.
-provider-path path: Specifies the search path that is to be used for looking for providers. Equivalently, the OPENSSL_MODULES environment variable may be set.
-propquery propq: Specifies the property query clause to be used when fetching algorithms from the loaded providers.

HISTORY

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

The -issuer_checks option is deprecated as of OpenSSL 1.1.0 and is silently ignored.

The -xcertform and -xkeyform options are obsolete since OpenSSL 3.0 and have no effect.

The interactive mode, which could be invoked by running "openssl" with no further arguments, was removed in OpenSSL 3.0, and running that program with no arguments is now equivalent to "openssl help".

COPYRIGHT

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

openssl
OpenSSL command line program

openssl command