+=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<trust store>.
+
+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<https://www.mozilla.org/en-US/about/governance/policies/security-group/certs/>.
+
+=over 4
+
+=item B<-CAfile> I<file>
+
+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<dir>
+
+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<openssl-rehash(1)> for information on creating this type of directory.
+
+=item B<-no-CApath>
+
+Do not use the default directory of trusted certificates.
+
+=item B<-CAstore> I<uri>
+
+Use I<uri> as a store of trusted CA certificates. The URI may
+indicate a single certificate, as well as a collection of them.
+With URIs in the C<file:> scheme, this acts as B<-CAfile> or
+B<-CApath>, depending on if the URI indicates a single file or
+directory.
+See L<ossl_store-file(7)> for more information on the C<file:> scheme.
+
+These certificates are also used when building the server certificate
+chain (for example with L<openssl-s_server(1)>) or client certificate
+chain (for example with L<openssl-s_time(1)>).
+
+=item B<-no-CAstore>
+
+Do not use the default store.
+
+=back
+
+=head2 Random State Options
+
+Prior to OpenSSL 1.1.1, 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 a trusted
+entropy source provided by the operating system. 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<files>
+
+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<file>
+
+Writes the seed data to the specified I<file> upon exit.
+This file can be used in a subsequent command invocation.
+
+=back
+
+=head2 Provider Options
+
+With the move to provider based cryptographic operations in OpenSSL 3.0,
+options were added to allow specific providers or sets of providers to be used.
+
+=over 4
+
+=item B<-provider> I<name>
+
+Use the provider identified by I<name> and use all the methods it
+implements (algorithms, key storage, etc.). This option can be specified
+multiple time to load more than one provider.
+
+=item B<-provider_path> I<path>
+
+Specify the search I<path> that is used to locate provider modules. The format
+of I<path> varies depending on the operating system being used.
+
+=back
+
+=head2 Extended Verification Options
+
+Sometimes there may be more than one certificate chain leading to an
+end-entity certificate.
+This usually happens when a root or intermediate CA signs a certificate
+for another a CA in other organization.
+Another reason is when a CA might have intermediates that use two different
+signature formats, such as a SHA-1 and a SHA-256 digest.
+
+The following options can be used to provide data that will allow the
+OpenSSL command to generate an alternative chain.
+
+=over 4
+
+=item B<-xchain_build>
+
+Specify whether the application should build the certificate chain to be
+provided to the server for the extra certificates via the B<-xkey>,
+B<-xcert>, and B<-xchain> options.
+
+=item B<-xkey> I<infile>, B<-xcert> I<infile>, B<-xchain>
+
+Specify an extra certificate, private key and certificate chain. These behave
+in the same manner as the B<-cert>, B<-key> and B<-cert_chain> options. When
+specified, the callback returning the first valid chain will be in use by the
+client.
+
+=item B<-xcertform> B<DER>|B<PEM>, B<-xkeyform> B<DER>|B<PEM>
+
+The input format for the extra certificate and key, respectively.
+See L<openssl(1)/Format Options> for details.
+
+=item B<-xchain_build>
+
+Specify whether the application should build the certificate chain to be
+provided to the server for the extra certificates via the B<-xkey>,
+B<-xcert>, and B<-xchain> options.
+
+=item B<-xcertform> B<DER>|B<PEM>, B<-xkeyform> B<DER>|B<PEM>
+
+The input format for the extra certificate and key, respectively.
+See L<openssl(1)/Format Options> for details.
+
+=back
+
+=head2 Verification Options
+
+Many OpenSSL commands verify certificates. The details of how each
+command handles errors are documented on the specific command page.
+
+Verification is a complicated process, consisting of a number of separate
+steps that are detailed in the following paragraphs.
+
+First, a certificate chain is built up starting from the supplied certificate
+and ending in a root CA. It is an error if the whole chain cannot be
+built up. The chain is built up by looking up the certificate that
+signed (or issued) the certificate. It then repeats the process, until
+it gets to a certificate that is self-issued.
+
+The process of looking up the issuer's certificate itself involves a number
+of steps. After all certificates whose subject name matches the issuer
+name of the current certificate are subject to further tests. The relevant
+authority key identifier components of the current certificate (if present)
+must match the subject key identifier (if present) and issuer and serial
+number of the candidate issuer, in addition the keyUsage extension of the
+candidate issuer (if present) must permit certificate signing.
+
+The lookup first looks in the list of untrusted certificates and if no match
+is found the remaining lookups are from the trusted certificates. The root CA
+is always looked up in the trusted certificate list: if the certificate to
+verify is a root certificate then an exact match must be found in the trusted
+list.
+
+The second step is to check every untrusted certificate's extensions
+for consistency with the supplied purpose. If the B<-purpose> option is
+not included then no checks are done. The supplied or "leaf" certificate
+must have extensions compatible with the supplied purpose and all other
+certificates must also be valid CA certificates. The precise extensions
+required are described in more detail in
+L<openssl-x509(1)/CERTIFICATE EXTENSIONS>.
+
+The third step is to check the trust settings on the root CA. The root
+CA should be trusted for the supplied purpose. For compatibility with
+previous versions of OpenSSL, a certificate with no trust settings is
+considered to be valid for all purposes.
+
+The fourth, and final, step is to check the validity of the certificate
+chain. The validity period is checked against the system time
+and the C<notBefore> and C<notAfter> dates in the certificate. The certificate
+signatures are also checked at this point. The B<-attime> flag may be
+used to specify a time other than "now."
+
+If all operations complete successfully then certificate is considered
+valid. If any operation fails then the certificate is not valid.
+
+The details of the processing steps can be fine-tuned with the
+following flags.
+
+=over 4
+
+=item B<-verbose>
+
+Print extra information about the operations being performed.
+
+=item B<-attime> I<timestamp>
+
+Perform validation checks using time specified by I<timestamp> and not
+current system time. I<timestamp> is the number of seconds since
+January 1, 1970 (i.e., the Unix Epoch).
+
+=item B<-no_check_time>
+
+This option suppresses checking the validity period of certificates and CRLs
+against the current time. If option B<-attime> is used to specify
+a verification time, the check is not suppressed.
+
+=item B<-x509_strict>
+
+This disables non-compliant workarounds for broken certificates.
+
+=item B<-ignore_critical>
+
+Normally if an unhandled critical extension is present which is not
+supported by OpenSSL the certificate is rejected (as required by RFC5280).
+If this option is set critical extensions are ignored.
+
+=item B<-issuer_checks>
+
+Ignored.
+
+=item B<-crl_check>
+
+Checks end entity certificate validity by attempting to look up a valid CRL.
+If a valid CRL cannot be found an error occurs.
+
+=item B<-crl_check_all>
+
+Checks the validity of B<all> certificates in the chain by attempting
+to look up valid CRLs.
+
+=item B<-use_deltas>
+
+Enable support for delta CRLs.
+
+=item B<-extended_crl>
+
+Enable extended CRL features such as indirect CRLs and alternate CRL
+signing keys.
+
+=item B<-suiteB_128_only>, B<-suiteB_128>, B<-suiteB_192>
+
+Enable the Suite B mode operation at 128 bit Level of Security, 128 bit or
+192 bit, or only 192 bit Level of Security respectively.
+See RFC6460 for details. In particular the supported signature algorithms are
+reduced to support only ECDSA and SHA256 or SHA384 and only the elliptic curves
+P-256 and P-384.
+
+=item B<-auth_level> I<level>
+
+Set the certificate chain authentication security level to I<level>.
+The authentication security level determines the acceptable signature and
+public key strength when verifying certificate chains. For a certificate
+chain to validate, the public keys of all the certificates must meet the
+specified security I<level>. The signature algorithm security level is
+enforced for all the certificates in the chain except for the chain's
+I<trust anchor>, which is either directly trusted or validated by means
+other than its signature. See L<SSL_CTX_set_security_level(3)> for the
+definitions of the available levels. The default security level is -1,
+or "not set". At security level 0 or lower all algorithms are acceptable.
+Security level 1 requires at least 80-bit-equivalent security and is broadly
+interoperable, though it will, for example, reject MD5 signatures or RSA
+keys shorter than 1024 bits.
+
+=item B<-partial_chain>
+
+Allow verification to succeed even if a I<complete> chain cannot be built to a
+self-signed trust-anchor, provided it is possible to construct a chain to a
+trusted certificate that might not be self-signed.
+
+=item B<-check_ss_sig>
+
+Verify the signature on the self-signed root CA. This is disabled by default
+because it doesn't add any security.
+
+=item B<-allow_proxy_certs>
+
+Allow the verification of proxy certificates.
+
+=item B<-trusted_first>
+
+As of OpenSSL 1.1.0 this option is on by default and cannot be disabled.
+
+=item B<-no_alt_chains>
+
+As of OpenSSL 1.1.0, since B<-trusted_first> always on, this option has no
+effect.
+
+=item B<-trusted> I<file>
+
+Parse I<file> as a set of one or more certificates in PEM format.
+All certificates must be self-signed, unless the
+B<-partial_chain> option is specified.
+This option implies the B<-no-CAfile>, B<-no-CApath>, and B<-no-CAstore> options
+and it cannot be used with the B<-CAfile>, B<-CApath> or B<-CAstore> options, so
+only certificates in the file are trust anchors.
+This option may be used multiple times.
+
+=item B<-untrusted> I<file>
+
+Parse I<file> as a set of one or more certificates in PEM format.
+All certificates are untrusted certificates that may be used to
+construct a certificate chain from the subject certificate to a trust anchor.
+This option may be used multiple times.
+
+=item B<-policy> I<arg>
+
+Enable policy processing and add I<arg> to the user-initial-policy-set (see
+RFC5280). The policy I<arg> can be an object name an OID in numeric form.
+This argument can appear more than once.
+
+=item B<-explicit_policy>
+
+Set policy variable require-explicit-policy (see RFC5280).
+
+=item B<-policy_check>
+
+Enables certificate policy processing.
+
+=item B<-policy_print>
+
+Print out diagnostics related to policy processing.
+
+=item B<-inhibit_any>
+
+Set policy variable inhibit-any-policy (see RFC5280).
+
+=item B<-inhibit_map>
+
+Set policy variable inhibit-policy-mapping (see RFC5280).
+
+=item B<-purpose> I<purpose>
+
+The intended use for the certificate. If this option is not specified, this
+command will not consider certificate purpose during chain verification.
+Currently accepted uses are B<sslclient>, B<sslserver>, B<nssslserver>,
+B<smimesign>, B<smimeencrypt>.
+
+=item B<-verify_depth> I<num>
+
+Limit the certificate chain to I<num> intermediate CA certificates.
+A maximal depth chain can have up to I<num>+2 certificates, since neither the
+end-entity certificate nor the trust-anchor certificate count against the
+B<-verify_depth> limit.
+
+=item B<-verify_email> I<email>
+
+Verify if I<email> matches the email address in Subject Alternative Name or
+the email in the subject Distinguished Name.
+
+=item B<-verify_hostname> I<hostname>
+
+Verify if I<hostname> matches DNS name in Subject Alternative Name or
+Common Name in the subject certificate.
+
+=item B<-verify_ip> I<ip>
+
+Verify if I<ip> matches the IP address in Subject Alternative Name of
+the subject certificate.
+
+=item B<-verify_name> I<name>
+
+Use default verification policies like trust model and required certificate
+policies identified by I<name>.
+The trust model determines which auxiliary trust or reject OIDs are applicable
+to verifying the given certificate chain.
+See the B<-addtrust> and B<-addreject> options for L<openssl-x509(1)>.
+Supported policy names include: B<default>, B<pkcs7>, B<smime_sign>,
+B<ssl_client>, B<ssl_server>.
+These mimics the combinations of purpose and trust settings used in SSL, CMS
+and S/MIME.
+As of OpenSSL 1.1.0, the trust model is inferred from the purpose when not
+specified, so the B<-verify_name> options are functionally equivalent to the
+corresponding B<-purpose> settings.
+
+=back
+
+=head2 Name Format Options
+
+OpenSSL provides fine-grain control over how the subject and issuer DN's are
+displayed.
+This is specified by using the B<-nameopt> option, which takes a
+comma-separated list of options from the following set.
+An option may be preceded by a minus sign, C<->, to turn it off.
+The default value is C<oneline>.
+The first four are the most commonly used.
+
+=over 4
+
+=item B<compat>
+
+Display the name using an old format from previous OpenSSL versions.
+
+=item B<RFC2253>
+
+Display the name using the format defined in RFC 2253.
+It is equivalent to B<esc_2253>, B<esc_ctrl>, B<esc_msb>, B<utf8>,
+B<dump_nostr>, B<dump_unknown>, B<dump_der>, B<sep_comma_plus>, B<dn_rev>
+and B<sname>.
+
+=item B<oneline>
+
+Display the name in one line, using a format that is more readable
+RFC 2253.
+It is equivalent to B<esc_2253>, B<esc_ctrl>, B<esc_msb>, B<utf8>,
+B<dump_nostr>, B<dump_der>, B<use_quote>, B<sep_comma_plus_space>,
+B<space_eq> and B<sname> options.
+
+=item B<multiline>
+
+Display the name using multiple lines.
+It is equivalent to B<esc_ctrl>, B<esc_msb>, B<sep_multiline>, B<space_eq>,
+B<lname> and B<align>.
+
+=item B<esc_2253>
+
+Escape the "special" characters in a field, as required by RFC 2253.
+That is, any of the characters C<,+"E<lt>E<gt>;>, C<#> at the beginning of
+a string and leading or trailing spaces.
+
+=item B<esc_2254>
+
+Escape the "special" characters in a field as required by RFC 2254 in a field.
+That is, the B<NUL> character and and of C<()*>.
+
+=item B<esc_ctrl>
+
+Escape non-printable ASCII characters, codes less than 0x20 (space)
+or greater than 0x7F (DELETE). They are displayed using RFC 2253 C<\XX>
+notation where B<XX> are the two hex digits representing the character value.
+
+=item B<esc_msb>
+
+Escape any characters with the most significant bit set, that is with
+values larger than 127, as described in B<esc_ctrl>.
+
+=item B<use_quote>
+
+Escapes some characters by surrounding the entire string with quotation
+marks, C<">.
+Without this option, individual special characters are preceeded with
+a backslash character, C<\>.
+
+=item B<utf8>
+
+Convert all strings to UTF-8 format first as required by RFC 2253.
+If the output device is UTF-8 compatible, then using this option (and
+not setting B<esc_msb>) may give the correct display of multibyte
+characters.
+If this option is not set, then multibyte characters larger than 0xFF
+will be output as C<\UXXXX> for 16 bits or C<\WXXXXXXXX> for 32 bits.
+In addition, any UTF8Strings will be converted to their character form first.
+
+=item B<ignore_type>
+
+This option does not attempt to interpret multibyte characters in any
+way. That is, the content octets are merely dumped as though one octet
+represents each character. This is useful for diagnostic purposes but
+will result in rather odd looking output.
+
+=item B<show_type>
+
+Display the type of the ASN1 character string before the value,
+such as C<BMPSTRING: Hello World>.
+
+=item B<dump_der>
+
+Any fields that would be output in hex format are displayed using
+the DER encoding of the field.
+If not set, just the content octets are displayed.
+Either way, the B<#XXXX...> format of RFC 2253 is used.
+
+=item B<dump_nostr>
+
+Dump non-character strings, such as ASN.1 B<OCTET STRING>.
+If this option is not set, then non character string types will be displayed
+as though each content octet represents a single character.
+
+=item B<dump_all>
+
+Dump all fields. When this used with B<dump_der>, this allows the
+DER encoding of the structure to be unambiguously determined.
+
+=item B<dump_unknown>
+
+Dump any field whose OID is not recognised by OpenSSL.
+
+=item B<sep_comma_plus>, B<sep_comma_plus_space>, B<sep_semi_plus_space>,
+B<sep_multiline>
+
+Specify the field separators. The first word is used between the
+Relative Distinguished Names (RDNs) and the second is between
+multiple Attribute Value Assertions (AVAs). Multiple AVAs are
+very rare and their use is discouraged.
+The options ending in "space" additionally place a space after the separator to make it more readable.
+The B<sep_multiline> starts each field on its own line, and uses "plus space"
+for the AVA separator.
+It also indents the fields by four characters.
+The default value is B<sep_comma_plus_space>.
+
+=item B<dn_rev>
+
+Reverse the fields of the DN as required by RFC 2253.
+This also reverses the order of multiple AVAs in a field, but this is
+permissible as there is no ordering on values.
+
+=item B<nofname>, B<sname>, B<lname>, B<oid>
+
+Specify how the field name is displayed.
+B<nofname> does not display the field at all.
+B<sname> uses the "short name" form (CN for commonName for example).
+B<lname> uses the long form.
+B<oid> represents the OID in numerical form and is useful for
+diagnostic purpose.
+
+=item B<align>
+
+Align field values for a more readable output. Only usable with
+B<sep_multiline>.
+
+=item B<space_eq>
+
+Places spaces round the equal sign, C<=>, character which follows the field
+name.
+
+=back
+
+=head2 TLS Version Options
+
+Several commands use SSL, TLS, or DTLS. By default, the commands use TLS and
+clients will offer the lowest and highest protocol version they support,
+and servers will pick the highest version that the client offers that is also
+supported by the server.
+
+The options below can be used to limit which protocol versions are used,
+and whether TCP (SSL and TLS) or UDP (DTLS) is used.
+Note that not all protocols and flags may be available, depending on how
+OpenSSL was built.
+
+=over 4
+
+=item B<-ssl3>, B<-tls1>, B<-tls1_1>, B<-tls1_2>, B<-tls1_3>, B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>, B<-no_tls1_3>
+
+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 B<no_> options.
+
+=item B<-dtls>, B<-dtls1>, B<-dtls1_2>
+
+These options specify to use DTLS instead of DLTS.
+With B<-dtls>, clients will negotiate any supported DTLS protocol version.
+Use the B<-dtls1> or B<-dtls1_2> options to support only DTLS1.0 or DTLS1.2,
+respectively.
+
+=back
+
+=head2 Engine Options
+
+=over 4
+
+=item B<-engine> I<id>
+
+Use the engine identified by I<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 L<config(5)/Engine Configuration Module>.
+
+=back
+
+=head1 ENVIRONMENT
+
+The OpenSSL library can be take some configuration parameters from the
+environment. Some of these variables are listed below. For information
+about specific commands, see L<openssl-engine(1)>, L<openssl-provider(1)>,
+L<openssl-rehash(1)>, and L<tsget(1)>.
+
+For information about the use of environment variables in configuration,
+see L<config(5)/ENVIRONMENT>.
+
+For information about querying or specifying CPU architecture flags, see
+L<OPENSSL_ia32cap(3)>, and L<OPENSSL_s390xcap(3)>.
+
+For information about all environment variables used by the OpenSSL libraries,
+see L<openssl-env(7)>.
+
+=over 4
+
+=item B<OPENSSL_TRACE=>I<name>[,...]
+
+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<TRACE>
+
+The tracing functionality.
+
+=item B<TLS>
+
+General SSL/TLS.
+
+=item B<TLS_CIPHER>
+
+SSL/TLS cipher.
+
+=item B<ENGINE_CONF>
+
+ENGINE configuration.
+
+=item B<ENGINE_TABLE>
+
+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<ENGINE_REF_COUNT>
+
+Reference counts in the ENGINE structure will be monitored with a line
+of generated for each change.
+
+=item B<PKCS5V2>
+
+PKCS#5 v2 keygen.
+
+=item B<PKCS12_KEYGEN>
+
+PKCS#12 key generation.
+
+=item B<PKCS12_DECRYPT>
+
+PKCS#12 decryption.
+
+=item B<X509V3_POLICY>
+
+Generates the complete policy tree at various point during X.509 v3
+policy evaluation.
+
+=item B<BN_CTX>
+
+BIGNUM context.
+
+=back
+
+=back
+
projects / openssl.git / blobdiff