{
    "mode": "man",
    "parameter": "openssl",
    "section": "",
    "url": "https://www.chedong.com/phpMan.php/man/openssl/json",
    "generated": "2026-10-22T20:42:38Z",
    "synopsis": "openssl command [ options ... ] [ parameters ... ]\nopenssl no-XXX [ options ]",
    "sections": {
        "NAME": {
            "content": "openssl - OpenSSL command line program\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "openssl command [ options ... ] [ parameters ... ]\n\nopenssl no-XXX [ options ]\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer (SSL v2/v3) and\nTransport Layer Security (TLS v1) network protocols and related cryptography standards\nrequired by them.\n\nThe openssl program is a command line program for using the various cryptography functions of\nOpenSSL's crypto library from the shell.  It can be used for\n\no  Creation and management of private keys, public keys and parameters\no  Public key cryptographic operations\no  Creation of X.509 certificates, CSRs and CRLs\no  Calculation of Message Digests and Message Authentication Codes\no  Encryption and Decryption with Ciphers\no  SSL/TLS Client and Server Tests\no  Handling of S/MIME signed or encrypted mail\no  Timestamp requests, generation and verification\n",
            "subsections": []
        },
        "COMMAND SUMMARY": {
            "content": "The openssl program provides a rich variety of commands (command in the \"SYNOPSIS\" above).\nEach command can have many options and argument parameters, shown above as options and\nparameters.\n\nDetailed documentation and use cases for most standard subcommands are available (e.g.,\nopenssl-x509(1)). The subcommand openssl-list(1) may be used to list subcommands.\n\nThe command no-XXX tests whether a command of the specified name is available.  If no command\nnamed XXX exists, it returns 0 (success) and prints no-XXX; otherwise it returns 1 and prints\nXXX.  In both cases, the output goes to stdout and nothing is printed to stderr.  Additional\ncommand line arguments are always ignored.  Since for each cipher there is a command of the\nsame name, this provides an easy way for shell scripts to test for the availability of\nciphers in the openssl program.  (no-XXX is not able to detect pseudo-commands such as quit,\nlist, or no-XXX itself.)\n",
            "subsections": [
                {
                    "name": "Configuration Option",
                    "content": "Many commands use an external configuration file for some or all of their arguments and have\na -config option to specify that file.  The default name of the file is openssl.cnf in the\ndefault certificate storage area, which can be determined from the openssl-version(1) command\nusing the -d or -a option.  The environment variable OPENSSLCONF can be used to specify a\ndifferent file location or to disable loading a configuration (using the empty string).\n\nAmong others, the configuration file can be used to load modules and to specify parameters\nfor generating certificates and random numbers.  See config(5) for details.\n"
                },
                {
                    "name": "Standard Commands",
                    "content": ""
                },
                {
                    "name": "asn1parse",
                    "content": "Parse an ASN.1 sequence.\n\nca  Certificate Authority (CA) Management.\n"
                },
                {
                    "name": "ciphers",
                    "content": "Cipher Suite Description Determination.\n\ncms CMS (Cryptographic Message Syntax) command.\n\ncrl Certificate Revocation List (CRL) Management.\n"
                },
                {
                    "name": "crl2pkcs7",
                    "content": "CRL to PKCS#7 Conversion.\n"
                },
                {
                    "name": "dgst",
                    "content": "Message Digest calculation. MAC calculations are superseded by openssl-mac(1).\n"
                },
                {
                    "name": "dhparam",
                    "content": "Generation  and Management of Diffie-Hellman Parameters. Superseded by openssl-genpkey(1)\nand openssl-pkeyparam(1).\n\ndsa DSA Data Management.\n"
                },
                {
                    "name": "dsaparam",
                    "content": "DSA  Parameter  Generation  and  Management.   Superseded   by   openssl-genpkey(1)   and\nopenssl-pkeyparam(1).\n\nec  EC (Elliptic curve) key processing.\n"
                },
                {
                    "name": "ecparam",
                    "content": "EC parameter manipulation and generation.\n\nenc Encryption, decryption, and encoding.\n"
                },
                {
                    "name": "engine",
                    "content": "Engine (loadable module) information and manipulation.\n"
                },
                {
                    "name": "errstr",
                    "content": "Error Number to Error String Conversion.\n"
                },
                {
                    "name": "fipsinstall",
                    "content": "FIPS configuration installation.\n"
                },
                {
                    "name": "gendsa",
                    "content": "Generation  of  DSA  Private  Key  from  Parameters. Superseded by openssl-genpkey(1) and\nopenssl-pkey(1).\n"
                },
                {
                    "name": "genpkey",
                    "content": "Generation of Private Key or Parameters.\n"
                },
                {
                    "name": "genrsa",
                    "content": "Generation of RSA Private Key. Superseded by openssl-genpkey(1).\n"
                },
                {
                    "name": "help",
                    "content": "Display information about a command's options.\n"
                },
                {
                    "name": "info",
                    "content": "Display diverse information built into the OpenSSL libraries.\n\nkdf Key Derivation Functions.\n"
                },
                {
                    "name": "list",
                    "content": "List algorithms and features.\n\nmac Message Authentication Code Calculation.\n"
                },
                {
                    "name": "nseq",
                    "content": "Create or examine a Netscape certificate sequence.\n"
                },
                {
                    "name": "ocsp",
                    "content": "Online Certificate Status Protocol command.\n"
                },
                {
                    "name": "passwd",
                    "content": "Generation of hashed passwords.\n"
                },
                {
                    "name": "pkcs12",
                    "content": "PKCS#12 Data Management.\n"
                },
                {
                    "name": "pkcs7",
                    "content": "PKCS#7 Data Management.\n"
                },
                {
                    "name": "pkcs8",
                    "content": "PKCS#8 format private key conversion command.\n"
                },
                {
                    "name": "pkey",
                    "content": "Public and private key management.\n"
                },
                {
                    "name": "pkeyparam",
                    "content": "Public key algorithm parameter management.\n"
                },
                {
                    "name": "pkeyutl",
                    "content": "Public key algorithm cryptographic operation command.\n"
                },
                {
                    "name": "prime",
                    "content": "Compute prime numbers.\n"
                },
                {
                    "name": "rand",
                    "content": "Generate pseudo-random bytes.\n"
                },
                {
                    "name": "rehash",
                    "content": "Create symbolic links to certificate and CRL files named by the hash values.\n\nreq PKCS#10 X.509 Certificate Signing Request (CSR) Management.\n\nrsa RSA key management.\n"
                },
                {
                    "name": "rsautl",
                    "content": "RSA  command  for  signing,  verification,  encryption,  and  decryption.  Superseded  by\nopenssl-pkeyutl(1).\n"
                },
                {
                    "name": "s_client",
                    "content": "This  implements a generic SSL/TLS client which can establish a transparent connection to\na remote server speaking SSL/TLS. It's intended for testing purposes  only  and  provides\nonly  rudimentary interface functionality but internally uses mostly all functionality of\nthe OpenSSL ssl library.\n"
                },
                {
                    "name": "s_server",
                    "content": "This implements a generic SSL/TLS server which accepts connections  from  remote  clients\nspeaking  SSL/TLS.  It's intended for testing purposes only and provides only rudimentary\ninterface functionality but internally uses mostly all functionality of the  OpenSSL  ssl\nlibrary.   It  provides  both  an  own  command  line  oriented  protocol for testing SSL\nfunctions and a simple HTTP response facility to emulate an SSL/TLS-aware webserver.\n"
                },
                {
                    "name": "s_time",
                    "content": "SSL Connection Timer.\n"
                },
                {
                    "name": "sess_id",
                    "content": "SSL Session Data Management.\n"
                },
                {
                    "name": "smime",
                    "content": "S/MIME mail processing.\n"
                },
                {
                    "name": "speed",
                    "content": "Algorithm Speed Measurement.\n"
                },
                {
                    "name": "spkac",
                    "content": "SPKAC printing and generating command.\n\nsrp Maintain SRP password file. This command is deprecated.\n"
                },
                {
                    "name": "storeutl",
                    "content": "Command to list and display certificates, keys, CRLs, etc.\n\nts  Time Stamping Authority command.\n"
                },
                {
                    "name": "verify",
                    "content": "X.509 Certificate Verification.   See  also  the  openssl-verification-options(1)  manual\npage.\n"
                },
                {
                    "name": "version",
                    "content": "OpenSSL Version Information.\n"
                },
                {
                    "name": "x509",
                    "content": "X.509 Certificate Data Management.\n"
                },
                {
                    "name": "Message Digest Commands",
                    "content": ""
                },
                {
                    "name": "blake2b512",
                    "content": "BLAKE2b-512 Digest\n"
                },
                {
                    "name": "blake2s256",
                    "content": "BLAKE2s-256 Digest\n\nmd2 MD2 Digest\n\nmd4 MD4 Digest\n\nmd5 MD5 Digest\n"
                },
                {
                    "name": "mdc2",
                    "content": "MDC2 Digest\n"
                },
                {
                    "name": "rmd160",
                    "content": "RMD-160 Digest\n"
                },
                {
                    "name": "sha1",
                    "content": "SHA-1 Digest\n"
                },
                {
                    "name": "sha224",
                    "content": "SHA-2 224 Digest\n"
                },
                {
                    "name": "sha256",
                    "content": "SHA-2 256 Digest\n"
                },
                {
                    "name": "sha384",
                    "content": "SHA-2 384 Digest\n"
                },
                {
                    "name": "sha512",
                    "content": "SHA-2 512 Digest\n"
                },
                {
                    "name": "sha3-224",
                    "content": "SHA-3 224 Digest\n"
                },
                {
                    "name": "sha3-256",
                    "content": "SHA-3 256 Digest\n"
                },
                {
                    "name": "sha3-384",
                    "content": "SHA-3 384 Digest\n"
                },
                {
                    "name": "sha3-512",
                    "content": "SHA-3 512 Digest\n"
                },
                {
                    "name": "shake128",
                    "content": "SHA-3 SHAKE128 Digest\n"
                },
                {
                    "name": "shake256",
                    "content": "SHA-3 SHAKE256 Digest\n\nsm3 SM3 Digest\n"
                },
                {
                    "name": "Encryption, Decryption, and Encoding Commands",
                    "content": "The following aliases provide convenient access to the most used encodings and ciphers.\n\nDepending  on  how  OpenSSL  was  configured  and  built,  not all ciphers listed here may be\npresent. See openssl-enc(1) for more information.\n\naes128, aes-128-cbc, aes-128-cfb, aes-128-ctr, aes-128-ecb, aes-128-ofb\nAES-128 Cipher\n\naes192, aes-192-cbc, aes-192-cfb, aes-192-ctr, aes-192-ecb, aes-192-ofb\nAES-192 Cipher\n\naes256, aes-256-cbc, aes-256-cfb, aes-256-ctr, aes-256-ecb, aes-256-ofb\nAES-256 Cipher\n\naria128, aria-128-cbc, aria-128-cfb, aria-128-ctr, aria-128-ecb, aria-128-ofb\nAria-128 Cipher\n\naria192, aria-192-cbc, aria-192-cfb, aria-192-ctr, aria-192-ecb, aria-192-ofb\nAria-192 Cipher\n\naria256, aria-256-cbc, aria-256-cfb, aria-256-ctr, aria-256-ecb, aria-256-ofb\nAria-256 Cipher\n"
                },
                {
                    "name": "base64",
                    "content": "Base64 Encoding\n\nbf, bf-cbc, bf-cfb, bf-ecb, bf-ofb\nBlowfish Cipher\n\ncamellia128, camellia-128-cbc, camellia-128-cfb, camellia-128-ctr, camellia-128-ecb,"
                },
                {
                    "name": "camellia-128-ofb",
                    "content": "Camellia-128 Cipher\n\ncamellia192, camellia-192-cbc, camellia-192-cfb, camellia-192-ctr, camellia-192-ecb,"
                },
                {
                    "name": "camellia-192-ofb",
                    "content": "Camellia-192 Cipher\n\ncamellia256, camellia-256-cbc, camellia-256-cfb, camellia-256-ctr, camellia-256-ecb,"
                },
                {
                    "name": "camellia-256-ofb",
                    "content": "Camellia-256 Cipher\n\ncast, cast-cbc\nCAST Cipher\n\ncast5-cbc, cast5-cfb, cast5-ecb, cast5-ofb\nCAST5 Cipher\n"
                },
                {
                    "name": "chacha20",
                    "content": "Chacha20 Cipher\n\ndes, des-cbc, des-cfb, des-ecb, des-ede, des-ede-cbc, des-ede-cfb, des-ede-ofb, des-ofb\nDES Cipher\n\ndes3, desx, des-ede3, des-ede3-cbc, des-ede3-cfb, des-ede3-ofb\nTriple-DES Cipher\n\nidea, idea-cbc, idea-cfb, idea-ecb, idea-ofb\nIDEA Cipher\n\nrc2, rc2-cbc, rc2-cfb, rc2-ecb, rc2-ofb\nRC2 Cipher\n\nrc4 RC4 Cipher\n\nrc5, rc5-cbc, rc5-cfb, rc5-ecb, rc5-ofb\nRC5 Cipher\n\nseed, seed-cbc, seed-cfb, seed-ecb, seed-ofb\nSEED Cipher\n\nsm4, sm4-cbc, sm4-cfb, sm4-ctr, sm4-ecb, sm4-ofb\nSM4 Cipher\n"
                }
            ]
        },
        "OPTIONS": {
            "content": "Details of which options  are  available  depend  on  the  specific  command.   This  section\ndescribes some common options with common behavior.\n",
            "subsections": [
                {
                    "name": "Common Options",
                    "content": ""
                },
                {
                    "name": "-help",
                    "content": "Provides  a  terse summary of all options.  If an option takes an argument, the \"type\" of\nargument is also given.\n\n--  This terminates the list of options. It is mostly useful if any filename parameters start\nwith a minus sign:\n\nopenssl verify [flags...] -- -cert1.pem...\n"
                },
                {
                    "name": "Format Options",
                    "content": "See openssl-format-options(1) for manual page.\n"
                },
                {
                    "name": "Pass Phrase Options",
                    "content": "See the openssl-passphrase-options(1) manual page.\n"
                },
                {
                    "name": "Random State Options",
                    "content": "Prior to OpenSSL 1.1.1, it was common for applications to store information about  the  state\nof  the random-number generator in a file that was loaded at startup and rewritten upon exit.\nOn modern operating systems, this is generally no  longer  necessary  as  OpenSSL  will  seed\nitself  from a trusted entropy source provided by the operating system. These flags are still\nsupported for special platforms or circumstances that might require them.\n\nIt is generally an error to use the same seed file more than once  and  every  use  of  -rand\nshould be paired with -writerand.\n"
                },
                {
                    "name": "-rand _",
                    "content": "A  file  or  files  containing  random  data  used  to  seed the random number generator.\nMultiple files can be specified separated by an OS-dependent character.  The separator is\n\";\" for MS-Windows, \",\" for OpenVMS, and \":\" for  all  others.  Another  way  to  specify\nmultiple files is to repeat this flag with different filenames.\n"
                },
                {
                    "name": "-writerand _",
                    "content": "Writes  the  seed  data  to  the  specified  file  upon exit.  This file can be used in a\nsubsequent command invocation.\n"
                },
                {
                    "name": "Certificate Verification Options",
                    "content": "See the openssl-verification-options(1) manual page.\n"
                },
                {
                    "name": "Name Format Options",
                    "content": "See the openssl-namedisplay-options(1) manual page.\n"
                },
                {
                    "name": "TLS Version Options",
                    "content": "Several commands use SSL, TLS, or DTLS. By default, the commands use  TLS  and  clients  will\noffer the lowest and highest protocol version they support, and servers will pick the highest\nversion that the client offers that is also supported by the server.\n\nThe options below can be used to limit which protocol versions are used, and whether TCP (SSL\nand  TLS)  or  UDP  (DTLS)  is used.  Note that not all protocols and flags may be available,\ndepending on how OpenSSL was built.\n"
                },
                {
                    "name": "-ssl3 -tls1 -tls1_1 -tls1_2 -tls1_3 -no_ssl3 -no_tls1 -no_tls1_1 -no_tls1_2",
                    "content": ""
                },
                {
                    "name": "-no_tls1_3",
                    "content": "These options require or disable the use of the specified SSL or TLS protocols.   When  a\nspecific  TLS  version  is required, only that version will be offered or accepted.  Only\none specific protocol can be given and it cannot be combined with any of the no options.\nThe no* options do not work with stime and ciphers commands but work with sclient  and\nsserver commands.\n"
                },
                {
                    "name": "-dtls -dtls1 -dtls1_2",
                    "content": "These options specify to use DTLS instead of TLS.  With -dtls, clients will negotiate any\nsupported  DTLS  protocol  version.   Use  the -dtls1 or -dtls12 options to support only\nDTLS1.0 or DTLS1.2, respectively.\n"
                },
                {
                    "name": "Engine Options",
                    "content": ""
                },
                {
                    "name": "-engine _",
                    "content": "Load the engine identified by id and use all the methods it implements  (algorithms,  key\nstorage, etc.), unless specified otherwise in the command-specific documentation or it is\nconfigured to do so, as described in \"Engine Configuration\" in config(5).\n\nThe  engine  will  be  used  for  key ids specified with -key and similar options when an\noption like -keyform engine is given.\n\nA special case is the \"loaderattic\" engine, which is meant  just  for  internal  OpenSSL\ntesting  purposes  and  supports  loading  keys,  parameters, certificates, and CRLs from\nfiles.  When this engine is used, files with such credentials are read via  this  engine.\nUsing the \"file:\" schema is optional; a plain file (path) name will do.\n\nOptions  specifying  keys,  like  -key  and  similar,  can use the generic OpenSSL engine key\nloading URI scheme \"org.openssl.engine:\" to retrieve private keys and public keys.   The  URI\nsyntax is as follows, in simplified form:\n\norg.openssl.engine:{engineid}:{keyid}\n\nWhere  \"{engineid}\"  is  the  identity/name  of the engine, and \"{keyid}\" is a key identifier\nthat's acceptable by that engine.  For example, when using an engine that interfaces  against\na  PKCS#11  implementation, the generic key URI would be something like this (this happens to\nbe an example for the PKCS#11 engine that's part of OpenSC):\n\n-key org.openssl.engine:pkcs11:labelsome-private-key\n\nAs  a  third  possibility,  for  engines  and  providers  that  have  implemented  their  own\nOSSLSTORELOADER(3),   \"org.openssl.engine:\"   should  not  be  necessary.   For  a  PKCS#11\nimplementation that has implemented such a loader, the PKCS#11 URI as  defined  in  RFC  7512\nshould be possible to use directly:\n\n-key pkcs11:object=some-private-key;pin-value=1234\n"
                },
                {
                    "name": "Provider Options",
                    "content": ""
                },
                {
                    "name": "-provider _",
                    "content": "Load  and  initialize the provider identified by name. The name can be also a path to the\nprovider module. In that case the provider name will be the specified path and  not  just\nthe  provider  module  name.   Interpretation of relative paths is platform specific. The\nconfigured \"MODULESDIR\" path, OPENSSLMODULES environment variable, or the path specified\nby -provider-path is prepended to relative paths.  See provider(7) for  a  more  detailed\ndescription.\n"
                },
                {
                    "name": "-provider-path _",
                    "content": "Specifies  the  search  path that is to be used for looking for providers.  Equivalently,\nthe OPENSSLMODULES environment variable may be set.\n"
                },
                {
                    "name": "-propquery _",
                    "content": "Specifies the property query clause to be used when fetching algorithms from  the  loaded\nproviders.  See property(7) for a more detailed description.\n"
                }
            ]
        },
        "ENVIRONMENT": {
            "content": "The  OpenSSL library can be take some configuration parameters from the environment.  Some of\nthese  variables  are  listed  below.   For  information   about   specific   commands,   see\nopenssl-engine(1), openssl-rehash(1), and tsget(1).\n\nFor information about the use of environment variables in configuration, see \"ENVIRONMENT\" in\nconfig(5).\n\nFor  information about querying or specifying CPU architecture flags, see OPENSSLia32cap(3),\nand OPENSSLs390xcap(3).\n\nFor  information  about  all  environment  variables  used  by  the  OpenSSL  libraries,  see\nopenssl-env(7).\n\nOPENSSLTRACE=name[,...]\nEnable  tracing  output of OpenSSL library, by name.  This output will only make sense if\nyou know OpenSSL internals well.  Also,  it  might  not  give  you  any  output  at  all,\ndepending on how OpenSSL was built.\n\nThe value is a comma separated list of names, with the following available:\n\nTRACE\nTraces the OpenSSL trace API itself.\n\nINIT\nTraces OpenSSL library initialization and cleanup.\n\nTLS Traces the TLS/SSL protocol.\n\nTLSCIPHER\nTraces the ciphers used by the TLS/SSL protocol.\n\nCONF\nShow details about provider and engine configuration.\n\nENGINETABLE\nThe  function that is used by RSA, DSA (etc) code to select registered ENGINEs, cache\ndefaults and functional references (etc), will generate debugging summaries.\n\nENGINEREFCOUNT\nReference counts in the ENGINE structure will be monitored with a line  of  generated\nfor each change.\n\nPKCS5V2\nTraces PKCS#5 v2 key generation.\n\nPKCS12KEYGEN\nTraces PKCS#12 key generation.\n\nPKCS12DECRYPT\nTraces PKCS#12 decryption.\n\nX509V3POLICY\nGenerates  the  complete  policy  tree  at  various  points  during  X.509  v3 policy\nevaluation.\n\nBNCTX\nTraces BIGNUM context operations.\n\nCMP Traces CMP client and server activity.\n\nSTORE\nTraces STORE operations.\n\nDECODER\nTraces decoder operations.\n\nENCODER\nTraces encoder operations.\n\nREFCOUNT\nTraces decrementing certain ASN.1 structure references.\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "openssl-asn1parse(1),  openssl-ca(1),  openssl-ciphers(1),  openssl-cms(1),   openssl-crl(1),\nopenssl-crl2pkcs7(1),        openssl-dgst(1),       openssl-dhparam(1),       openssl-dsa(1),\nopenssl-dsaparam(1), openssl-ec(1),  openssl-ecparam(1),  openssl-enc(1),  openssl-engine(1),\nopenssl-errstr(1),  openssl-gendsa(1), openssl-genpkey(1), openssl-genrsa(1), openssl-kdf(1),\nopenssl-list(1),   openssl-mac(1),   openssl-nseq(1),   openssl-ocsp(1),   openssl-passwd(1),\nopenssl-pkcs12(1), openssl-pkcs7(1), openssl-pkcs8(1), openssl-pkey(1), openssl-pkeyparam(1),\nopenssl-pkeyutl(1),  openssl-prime(1),  openssl-rand(1),  openssl-rehash(1),  openssl-req(1),\nopenssl-rsa(1),      openssl-rsautl(1),       openssl-sclient(1),       openssl-sserver(1),\nopenssl-stime(1),  openssl-sessid(1), openssl-smime(1), openssl-speed(1), openssl-spkac(1),\nopenssl-srp(1), openssl-storeutl(1),  openssl-ts(1),  openssl-verify(1),  openssl-version(1),\nopenssl-x509(1), config(5), crypto(7), openssl-env(7).  ssl(7), x509v3config(5)\n",
            "subsections": []
        },
        "HISTORY": {
            "content": "The  list  -XXX-algorithms options were added in OpenSSL 1.0.0; For notes on the availability\nof other commands, see their individual manual pages.\n\nThe -issuerchecks option is deprecated as of OpenSSL 1.1.0 and is silently ignored.\n\nThe -xcertform and -xkeyform options are obsolete since OpenSSL 3.0 and have no effect.\n\nThe interactive mode, which could be invoked by running \"openssl\" with no further  arguments,\nwas  removed  in OpenSSL 3.0, and running that program with no arguments is now equivalent to\n\"openssl help\".\n",
            "subsections": []
        },
        "COPYRIGHT": {
            "content": "Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved.\n\nLicensed under the Apache License 2.0 (the \"License\").  You may not use this file  except  in\ncompliance  with  the  License.   You  can  obtain  a  copy in the file LICENSE in the source\ndistribution or at <https://www.openssl.org/source/license.html>.\n\n3.0.13                                       2026-07-29                                OPENSSL(1SSL)",
            "subsections": []
        }
    },
    "summary": "openssl - OpenSSL command line program",
    "flags": [
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "Provides a terse summary of all options. If an option takes an argument, the \"type\" of argument is also given. -- This terminates the list of options. It is mostly useful if any filename parameters start with a minus sign: openssl verify [flags...] -- -cert1.pem..."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "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."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "Writes the seed data to the specified file upon exit. This file can be used in a subsequent command invocation."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": ""
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "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 stime and ciphers commands but work with sclient and sserver commands."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "These options specify to use DTLS instead of TLS. With -dtls, clients will negotiate any supported DTLS protocol version. Use the -dtls1 or -dtls12 options to support only DTLS1.0 or DTLS1.2, respectively."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "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 config(5). 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 \"loaderattic\" 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:labelsome-private-key As a third possibility, for engines and providers that have implemented their own OSSLSTORELOADER(3), \"org.openssl.engine:\" should not be necessary. 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"
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "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, OPENSSLMODULES environment variable, or the path specified by -provider-path is prepended to relative paths. See provider(7) for a more detailed description."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "Specifies the search path that is to be used for looking for providers. Equivalently, the OPENSSLMODULES environment variable may be set."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "Specifies the property query clause to be used when fetching algorithms from the loaded providers. See property(7) for a more detailed description."
        }
    ],
    "examples": [],
    "see_also": [
        {
            "name": "openssl-asn1parse",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-asn1parse/1/json"
        },
        {
            "name": "openssl-ca",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-ca/1/json"
        },
        {
            "name": "openssl-ciphers",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-ciphers/1/json"
        },
        {
            "name": "openssl-cms",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-cms/1/json"
        },
        {
            "name": "openssl-crl",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-crl/1/json"
        },
        {
            "name": "openssl-crl2pkcs7",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-crl2pkcs7/1/json"
        },
        {
            "name": "openssl-dgst",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-dgst/1/json"
        },
        {
            "name": "openssl-dhparam",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-dhparam/1/json"
        },
        {
            "name": "openssl-dsa",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-dsa/1/json"
        },
        {
            "name": "openssl-dsaparam",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-dsaparam/1/json"
        },
        {
            "name": "openssl-ec",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-ec/1/json"
        },
        {
            "name": "openssl-ecparam",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-ecparam/1/json"
        },
        {
            "name": "openssl-enc",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-enc/1/json"
        },
        {
            "name": "openssl-engine",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-engine/1/json"
        },
        {
            "name": "openssl-errstr",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-errstr/1/json"
        },
        {
            "name": "openssl-gendsa",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-gendsa/1/json"
        },
        {
            "name": "openssl-genpkey",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-genpkey/1/json"
        },
        {
            "name": "openssl-genrsa",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-genrsa/1/json"
        },
        {
            "name": "openssl-kdf",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-kdf/1/json"
        },
        {
            "name": "openssl-list",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-list/1/json"
        },
        {
            "name": "openssl-mac",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-mac/1/json"
        },
        {
            "name": "openssl-nseq",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-nseq/1/json"
        },
        {
            "name": "openssl-ocsp",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-ocsp/1/json"
        },
        {
            "name": "openssl-passwd",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-passwd/1/json"
        },
        {
            "name": "openssl-pkcs12",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-pkcs12/1/json"
        },
        {
            "name": "openssl-pkcs7",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-pkcs7/1/json"
        },
        {
            "name": "openssl-pkcs8",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-pkcs8/1/json"
        },
        {
            "name": "openssl-pkey",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-pkey/1/json"
        },
        {
            "name": "openssl-pkeyparam",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-pkeyparam/1/json"
        },
        {
            "name": "openssl-pkeyutl",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-pkeyutl/1/json"
        },
        {
            "name": "openssl-prime",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-prime/1/json"
        },
        {
            "name": "openssl-rand",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-rand/1/json"
        },
        {
            "name": "openssl-rehash",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-rehash/1/json"
        },
        {
            "name": "openssl-req",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-req/1/json"
        },
        {
            "name": "openssl-rsa",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-rsa/1/json"
        },
        {
            "name": "openssl-rsautl",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-rsautl/1/json"
        },
        {
            "name": "openssl-sclient",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-sclient/1/json"
        },
        {
            "name": "openssl-sserver",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-sserver/1/json"
        },
        {
            "name": "openssl-stime",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-stime/1/json"
        },
        {
            "name": "openssl-sessid",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-sessid/1/json"
        },
        {
            "name": "openssl-smime",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-smime/1/json"
        },
        {
            "name": "openssl-speed",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-speed/1/json"
        },
        {
            "name": "openssl-spkac",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-spkac/1/json"
        },
        {
            "name": "openssl-srp",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-srp/1/json"
        },
        {
            "name": "openssl-storeutl",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-storeutl/1/json"
        },
        {
            "name": "openssl-ts",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-ts/1/json"
        },
        {
            "name": "openssl-verify",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-verify/1/json"
        },
        {
            "name": "openssl-version",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-version/1/json"
        },
        {
            "name": "openssl-x509",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-x509/1/json"
        },
        {
            "name": "config",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/config/5/json"
        },
        {
            "name": "crypto",
            "section": "7",
            "url": "https://www.chedong.com/phpMan.php/man/crypto/7/json"
        },
        {
            "name": "openssl-env",
            "section": "7",
            "url": "https://www.chedong.com/phpMan.php/man/openssl-env/7/json"
        },
        {
            "name": "ssl",
            "section": "7",
            "url": "https://www.chedong.com/phpMan.php/man/ssl/7/json"
        },
        {
            "name": "x509v3config",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/x509v3config/5/json"
        }
    ],
    "tldr": {
        "source": "official",
        "description": "OpenSSL cryptographic toolkit.",
        "examples": [
            {
                "description": "Generate a private key and encrypt the output file using AES-256",
                "command": "openssl genpkey -algorithm {{rsa|ec}} -out {{path/to/private.key}} -aes256"
            },
            {
                "description": "Generate the corresponding public key from the private key `private.key` using `rsa`",
                "command": "openssl rsa -in {{path/to/private.key}} -pubout -out {{path/to/public.key}}"
            },
            {
                "description": "Generate a self-signed certificate valid for a specified number of days (365)",
                "command": "openssl req -new -x509 -key {{path/to/private.key}} -out {{path/to/certificate.crt}} -days 365"
            },
            {
                "description": "Convert a certificate to `.pem` or `.der` format",
                "command": "openssl x509 -in {{path/to/certificate.crt}} -out {{path/to/certificate.pem|path/to/certificate.der}} -outform {{pem|der}}"
            },
            {
                "description": "Check certificate details",
                "command": "openssl x509 -in {{path/to/certificate.crt}} -text -noout"
            },
            {
                "description": "Generate a certificate signing request (CSR)",
                "command": "openssl req -new -key {{path/to/private.key}} -out {{path/to/request.csr}}"
            },
            {
                "description": "Display help",
                "command": "openssl help"
            },
            {
                "description": "Display version",
                "command": "openssl version"
            }
        ]
    }
}