HP Open Source Security for OpenVMS Volume 2: HP SSL for OpenVMS > OpenSSL Command Line Interface (CLI) Reference


  Table of Contents



openssl — OpenSSL command line tool


openssl command [ command_opts ] [ command_args ] openssl [ list-standard-commands | list-message-digest-commands | list-cipher-commands ] openssl no-XXX [ arbitrary options ]


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 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

 o  Creation of RSA, DH and DSA key parameters
o Creation of X.509 certificates, CSRs and CRLs
o Calculation of Message Digests
o Encryption and Decryption with Ciphers
o SSL/TLS Client and Server Tests
o Handling of S/MIME signed or encrypted mail


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

The pseudo-commands list-standard-commands, list-message-digest-commands, and list-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 in the present openssl utility.

The pseudo-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-... -commands, or no-XXX itself.)


  • asn1parse

    Parse an ASN.1 sequence.

  • ca

    Certificate Authority (CA) Management.

  • ciphers

    Cipher Suite Description Determination.

  • crl

    Certificate Revocation List (CRL) Management.

  • crl2pkcs7

    CRL to PKCS#7 Conversion.

  • dgst

    Message Digest Calculation.

  • dh

    Diffie-Hellman Parameter Management. Obsoleted by dhparam.

  • dsa

    DSA Data Management.

  • dsaparam

    DSA Parameter Generation.

  • enc

    Encoding with Ciphers.

  • errstr

    Error Number to Error String Conversion.

  • dhparam

    Generation and Management of Diffie-Hellman Parameters.

  • gendh

    Generation of Diffie-Hellman Parameters. Obsoleted by dhparam.

  • gendsa

    Generation of DSA Parameters.

  • genrsa

    Generation of RSA Parameters.

  • ocsp

    Online Certificate Status Protocol utility.

  • passwd

    Generation of hashed passwords.

  • pkcs12

    PKCS#12 Data Management.

  • pkcs7

    PKCS#7 Data Management.

  • rand

    Generate pseudo-random bytes.

  • req

    X.509 Certificate Signing Request (CSR) Management.

  • rsa

    RSA Data Management.

  • rsautl

    RSA utility for signing, verification, encryption, and decryption.

  • 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.

  • verify

    X.509 Certificate Verification.

  • version

    OpenSSL Version Information.

  • x509

    X.509 Certificate Data Management.


  • md2

    MD2 Digest

  • md5

    MD5 Digest

  • mdc2

    MDC2 Digest

  • rmd160

    RMD-160 Digest

  • sha

    SHA Digest

  • sha1

    SHA-1 Digest


  • base64

    Base64 Encoding

  • bf bf-cbc bf-cfb bf-ecb bf-ofb

    Blowfish Cipher

  • cast cast-cbc

    CAST Cipher

  • cast5-cbc cast5-cfb cast5-ecb cast5-ofb

    CAST5 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


Several commands accept password arguments, typically using -passin and -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.

  • pass:password

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

  • env:var

    obtain the password from the environment variable 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.

  • file:pathname

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

  • fd:number

    read the password from the file descriptor number. This can be used to send the data via a pipe for example.

  • stdin

    read the password from standard input.


asn1parse(1), ca(1), config(5), crl(1), crl2pkcs7(1), dgst(1), dhparam(1), dsa(1), dsaparam(1), enc(1), gendsa(1), genrsa(1), nseq(1), openssl(1), passwd(1), pkcs12(1), pkcs7(1), pkcs8(1), rand(1), req(1), rsa(1), rsautl(1), s_client(1), s_server(1), smime(1), spkac(1), verify(1), version(1), x509(1), crypto(3), ssl(3)


The openssl(1) document appeared in OpenSSL 0.9.2. The list-XXX -commands pseudo-commands were added in OpenSSL 0.9.3; the no-XXX pseudo-commands were added in OpenSSL 0.9.5a. For notes on the availability of other commands, see their individual manual pages.