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 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), s_time(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.