OPENSSL(1) OpenSSL OPENSSL(1)
openssl - OpenSSL command line tool
openssl command [ command_opts ] [ command_args ]
openssl [ list-standard-commands │ list-message-digest-commands │ list-
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 cryp-
tography 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 argu-
ments (command_opts and command_args in the SYNOPSIS).
The pseudo-commands list-standard-commands, list-message-digest-com-
mands, 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 util-
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
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
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 con-
nections from remote clients speaking SSL/TLS. It’s intended
for testing purposes only and provides only rudimentary
interface functionality but internally uses mostly all func-
tionality 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
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.
MESSAGE DIGEST COMMANDS
md2 MD2 Digest
md5 MD5 Digest
mdc2 MDC2 Digest
rmd160 RMD-160 Digest
sha SHA Digest
sha1 SHA-1 Digest
ENCODING AND CIPHER COMMANDS
base64 Base64 Encoding
bf bf-cbc bf-cfb bf-ecb bf-ofb
cast5-cbc cast5-cfb cast5-ecb cast5-ofb
des des-cbc des-cfb des-ecb des-ede des-ede-cbc des-ede-cfb des-ede-ofb
des3 desx des-ede3 des-ede3-cbc des-ede3-cfb des-ede3-ofb
idea idea-cbc idea-cfb idea-ecb idea-ofb
rc2 rc2-cbc rc2-cfb rc2-ecb rc2-ofb
rc4 RC4 Cipher
rc5 rc5-cbc rc5-cfb rc5-ecb rc5-ofb
PASS PHRASE ARGUMENTS
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.
the actual password is password. Since the password is visi-
ble 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.
the first line of pathname is the password. If the same path-
name 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-com-
mands 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.
0.9.7f 2004-01-04 OPENSSL(1)
Man(1) output converted with