=pod =head1 NAME openssl - OpenSSL command line tool =head1 SYNOPSIS B I [ I ... ] [ I ... ] B B B<-standard-commands> | B<-digest-commands> | B<-cipher-commands> | B<-cipher-algorithms> | B<-digest-algorithms> | B<-mac-algorithms> | B<-public-key-algorithms> B BI [ I ] =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 program is a command line tool for using the various cryptography functions of OpenSSL's B 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 program provides a rich variety of sub-commands (I in the SYNOPSIS above), each of which often has a wealth of options and arguments (I and I in the SYNOPSIS). Detailed documentation and use cases for most standard subcommands are available (e.g., L or L). 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 can be used to specify the location of the file. If the environment variable is not specified, then the file is named F 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 BI tests whether a command of the specified name is available. If no command named I exists, it returns 0 (success) and prints BI; otherwise it returns 1 and prints I. In both cases, the output goes to B and nothing is printed to B. 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 program. (BI is not able to detect pseudo-commands such as B, B, or BI itself.) =head2 Standard Sub-commands =over 4 =item B Parse an ASN.1 sequence. =item B Certificate Authority (CA) Management. =item B Cipher Suite Description Determination. =item B CMS (Cryptographic Message Syntax) utility. =item B Certificate Revocation List (CRL) Management. =item B CRL to PKCS#7 Conversion. =item B Message Digest calculation. MAC calculations are superseded by L. =item B Diffie-Hellman Parameter Management. Obsoleted by L. =item B Generation and Management of Diffie-Hellman Parameters. Superseded by L and L. =item B DSA Data Management. =item B DSA Parameter Generation and Management. Superseded by L and L. =item B EC (Elliptic curve) key processing. =item B EC parameter manipulation and generation. =item B Encoding with Ciphers. =item B Engine (loadable module) information and manipulation. =item B Error Number to Error String Conversion. =item B Generation of Diffie-Hellman Parameters. Obsoleted by L. =item B Generation of DSA Private Key from Parameters. Superseded by L and L. =item B Generation of Private Key or Parameters. =item B Generation of RSA Private Key. Superseded by L. =item B Display diverse information built into the OpenSSL libraries. =item B Key Derivation Functions. =item B Message Authentication Code Calculation. =item B Create or examine a Netscape certificate sequence. =item B Online Certificate Status Protocol utility. =item B Generation of hashed passwords. =item B PKCS#12 Data Management. =item B PKCS#7 Data Management. =item B PKCS#8 format private key conversion tool. =item B Public and private key management. =item B Public key algorithm parameter management. =item B Public key algorithm cryptographic operation utility. =item B Compute prime numbers. =item B Generate pseudo-random bytes. =item B Create symbolic links to certificate and CRL files named by the hash values. =item B PKCS#10 X.509 Certificate Signing Request (CSR) Management. =item B RSA key management. =item B RSA utility for signing, verification, encryption, and decryption. Superseded by L. =item B 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 library. =item B 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 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 SSL Connection Timer. =item B SSL Session Data Management. =item B S/MIME mail processing. =item B Algorithm Speed Measurement. =item B SPKAC printing and generating utility. =item B Maintain SRP password file. =item B Utility to list and display certificates, keys, CRLs, etc. =item B Time Stamping Authority tool (client/server). =item B X.509 Certificate Verification. =item B OpenSSL Version Information. =item B X.509 Certificate Data Management. =back =head2 Message Digest Commands =over 4 =item B BLAKE2b-512 Digest =item B BLAKE2s-256 Digest =item B MD2 Digest =item B MD4 Digest =item B MD5 Digest =item B MDC2 Digest =item B RMD-160 Digest =item B SHA-1 Digest =item B SHA-2 224 Digest =item B SHA-2 256 Digest =item B SHA-2 384 Digest =item B SHA-2 512 Digest =item B SHA-3 224 Digest =item B SHA-3 256 Digest =item B SHA-3 384 Digest =item B SHA-3 512 Digest =item B SHA-3 SHAKE128 Digest =item B SHA-3 SHAKE256 Digest =item B 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 for more information and command usage. =over 4 =item B, B, B, B, B, B AES-128 Cipher =item B, B, B, B, B, B AES-192 Cipher =item B, B, B, B, B, B AES-256 Cipher =item B, B, B, B, B, B Aria-128 Cipher =item B, B, B, B, B, B Aria-192 Cipher =item B, B, B, B, B, B Aria-256 Cipher =item B Base64 Encoding =item B, B, B, B, B Blowfish Cipher =item B, B, B, B, B, B Camellia-128 Cipher =item B, B, B, B, B, B Camellia-192 Cipher =item B, B, B, B, B, B Camellia-256 Cipher =item B, B CAST Cipher =item B, B, B, B CAST5 Cipher =item B Chacha20 Cipher =item B, B, B, B, B, B, B, B, B DES Cipher =item B, B, B, B, B, B Triple-DES Cipher =item B, B, B, B, B IDEA Cipher =item B, B, B, B, B RC2 Cipher =item B RC4 Cipher =item B, B, B, B, B RC5 Cipher =item B, B, B, B, B SEED Cipher =item B, B, B, B, B, B 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 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. =over 4 =item BI The actual password is I. Since the password is visible to utilities (like 'ps' under Unix) this form should only be used where security is not important. =item BI Obtain the password from the environment variable I. 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 BI The first line of I is the password. If the same I 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 need not refer to a regular file: it could for example refer to a device or named pipe. =item BI Read the password from the file descriptor I. This can be used to send the data via a pipe for example. =item B 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. 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. =over 4 =item B<-CAfile> I 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 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 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 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 Writes the seed data to the specified I upon exit. This file can be used in a subsequent command invocation. =back =head1 ENVIRONMENT =over 4 =item BI[,...] 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 The tracing functionality. =item B General SSL/TLS. =item B SSL/TLS cipher. =item B ENGINE configuration. =item B 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 Reference counts in the ENGINE structure will be monitored with a line of generated for each change. =item B PKCS#5 v2 keygen. =item B PKCS#12 key generation. =item B PKCS#12 decryption. =item B Generates the complete policy tree at various point during X.509 v3 policy evaluation. =item B BIGNUM context. =back =back =head1 SEE ALSO L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L =head1 HISTORY The B -IB<-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. =cut