Provided by: openssl_1.1.1-1ubuntu2_amd64 bug

NAME

       openssl-verify, verify - Utility to verify certificates

SYNOPSIS

       openssl verify [-help] [-CAfile file] [-CApath directory] [-no-CAfile] [-no-CApath]
       [-allow_proxy_certs] [-attime timestamp] [-check_ss_sig] [-CRLfile file] [-crl_download]
       [-crl_check] [-crl_check_all] [-engine id] [-explicit_policy] [-extended_crl]
       [-ignore_critical] [-inhibit_any] [-inhibit_map] [-nameopt option] [-no_check_time]
       [-partial_chain] [-policy arg] [-policy_check] [-policy_print] [-purpose purpose]
       [-suiteB_128] [-suiteB_128_only] [-suiteB_192] [-trusted_first] [-no_alt_chains]
       [-untrusted file] [-trusted file] [-use_deltas] [-verbose] [-auth_level level]
       [-verify_depth num] [-verify_email email] [-verify_hostname hostname] [-verify_ip ip]
       [-verify_name name] [-x509_strict] [-show_chain] [-] [certificates]

DESCRIPTION

       The verify command verifies certificate chains.

OPTIONS

       -help
           Print out a usage message.

       -CAfile file
           A file of trusted certificates.  The file should contain one or more certificates in
           PEM format.

       -CApath directory
           A directory of trusted certificates. The certificates should have names of the form:
           hash.0 or have symbolic links to them of this form ("hash" is the hashed certificate
           subject name: see the -hash option of the x509 utility). Under Unix the c_rehash
           script will automatically create symbolic links to a directory of certificates.

       -no-CAfile
           Do not load the trusted CA certificates from the default file location.

       -no-CApath
           Do not load the trusted CA certificates from the default directory location.

       -allow_proxy_certs
           Allow the verification of proxy certificates.

       -attime timestamp
           Perform validation checks using time specified by timestamp and not current system
           time. timestamp is the number of seconds since 01.01.1970 (UNIX time).

       -check_ss_sig
           Verify the signature on the self-signed root CA. This is disabled by default because
           it doesn't add any security.

       -CRLfile file
           The file should contain one or more CRLs in PEM format.  This option can be specified
           more than once to include CRLs from multiple files.

       -crl_download
           Attempt to download CRL information for this certificate.

       -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.

       -crl_check_all
           Checks the validity of all certificates in the chain by attempting to look up valid
           CRLs.

       -engine id
           Specifying an engine id will cause verify(1) to attempt to load the specified engine.
           The engine will then be set as the default for all its supported algorithms.  If you
           want to load certificates or CRLs that require engine support via any of the -trusted,
           -untrusted or -CRLfile options, the -engine option must be specified before those
           options.

       -explicit_policy
           Set policy variable require-explicit-policy (see RFC5280).

       -extended_crl
           Enable extended CRL features such as indirect CRLs and alternate CRL signing keys.

       -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.

       -inhibit_any
           Set policy variable inhibit-any-policy (see RFC5280).

       -inhibit_map
           Set policy variable inhibit-policy-mapping (see RFC5280).

       -nameopt option
           Option which determines how the subject or issuer names are displayed. The option
           argument can be a single option or multiple options separated by commas.
           Alternatively the -nameopt switch may be used more than once to set multiple options.
           See the x509(1) manual page for details.

       -no_check_time
           This option suppresses checking the validity period of certificates and CRLs against
           the current time. If option -attime timestamp is used to specify a verification time,
           the check is not suppressed.

       -partial_chain
           Allow verification to succeed even if a 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.

       -policy arg
           Enable policy processing and add arg to the user-initial-policy-set (see RFC5280). The
           policy arg can be an object name an OID in numeric form.  This argument can appear
           more than once.

       -policy_check
           Enables certificate policy processing.

       -policy_print
           Print out diagnostics related to policy processing.

       -purpose purpose
           The intended use for the certificate. If this option is not specified, verify will not
           consider certificate purpose during chain verification.  Currently accepted uses are
           sslclient, sslserver, nssslserver, smimesign, smimeencrypt. See the VERIFY OPERATION
           section for more information.

       -suiteB_128_only, -suiteB_128, -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.

       -trusted_first
           When constructing the certificate chain, use the trusted certificates specified via
           -CAfile, -CApath or -trusted before any certificates specified via -untrusted.  This
           can be useful in environments with Bridge or Cross-Certified CAs.  As of OpenSSL 1.1.0
           this option is on by default and cannot be disabled.

       -no_alt_chains
           By default, unless -trusted_first is specified, when building a certificate chain, if
           the first certificate chain found is not trusted, then OpenSSL will attempt to replace
           untrusted issuer certificates with certificates from the trust store to see if an
           alternative chain can be found that is trusted.  As of OpenSSL 1.1.0, with
           -trusted_first always on, this option has no effect.

       -untrusted file
           A file of additional untrusted certificates (intermediate issuer CAs) used to
           construct a certificate chain from the subject certificate to a trust-anchor.  The
           file should contain one or more certificates in PEM format.  This option can be
           specified more than once to include untrusted certificates from multiple files.

       -trusted file
           A file of trusted certificates, which must be self-signed, unless the -partial_chain
           option is specified.  The file contains one or more certificates in PEM format.  With
           this option, no additional (e.g., default) certificate lists are consulted.  That is,
           the only trust-anchors are those listed in file.  This option can be specified more
           than once to include trusted certificates from multiple files.  This option implies
           the -no-CAfile and -no-CApath options.  This option cannot be used in combination with
           either of the -CAfile or -CApath options.

       -use_deltas
           Enable support for delta CRLs.

       -verbose
           Print extra information about the operations being performed.

       -auth_level level
           Set the certificate chain authentication security level to 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 level.  The signature algorithm
           security level is enforced for all the certificates in the chain except for the
           chain's trust anchor, which is either directly trusted or validated by means other
           than its signature.  See 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.

       -verify_depth num
           Limit the certificate chain to num intermediate CA certificates.  A maximal depth
           chain can have up to num+2 certificates, since neither the end-entity certificate nor
           the trust-anchor certificate count against the -verify_depth limit.

       -verify_email email
           Verify if the email matches the email address in Subject Alternative Name or the email
           in the subject Distinguished Name.

       -verify_hostname hostname
           Verify if the hostname matches DNS name in Subject Alternative Name or Common Name in
           the subject certificate.

       -verify_ip ip
           Verify if the ip matches the IP address in Subject Alternative Name of the subject
           certificate.

       -verify_name name
           Use default verification policies like trust model and required certificate policies
           identified by name.  The trust model determines which auxiliary trust or reject OIDs
           are applicable to verifying the given certificate chain.  See the -addtrust and
           -addreject options of the x509(1) command-line utility.  Supported policy names
           include: default, pkcs7, smime_sign, ssl_client, 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
           -verify_name options are functionally equivalent to the corresponding -purpose
           settings.

       -x509_strict
           For strict X.509 compliance, disable non-compliant workarounds for broken
           certificates.

       -show_chain
           Display information about the certificate chain that has been built (if successful).
           Certificates in the chain that came from the untrusted list will be flagged as
           "untrusted".

       -   Indicates the last option. All arguments following this are assumed to be certificate
           files. This is useful if the first certificate filename begins with a -.

       certificates
           One or more certificates to verify. If no certificates are given, verify will attempt
           to read a certificate from standard input. Certificates must be in PEM format.

VERIFY OPERATION

       The verify program uses the same functions as the internal SSL and S/MIME verification,
       therefore this description applies to these verify operations too.

       There is one crucial difference between the verify operations performed by the verify
       program: wherever possible an attempt is made to continue after an error whereas normally
       the verify operation would halt on the first error. This allows all the problems with a
       certificate chain to be determined.

       The verify operation consists of a number of separate steps.

       Firstly a certificate chain is built up starting from the supplied certificate and ending
       in the root CA.  It is an error if the whole chain cannot be built up.  The chain is built
       up by looking up the issuers certificate of the current certificate.  If a certificate is
       found which is its own issuer it is assumed to be the root CA.

       The process of 'looking up the issuers 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 operation is to check every untrusted certificate's extensions for consistency
       with the supplied purpose. If the -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 the CERTIFICATE EXTENSIONS section of
       the x509 utility.

       The third operation 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 final operation is to check the validity of the certificate chain. The validity period
       is checked against the current system time and the notBefore and notAfter dates in the
       certificate. The certificate signatures are also checked at this point.

       If all operations complete successfully then certificate is considered valid. If any
       operation fails then the certificate is not valid.

DIAGNOSTICS

       When a verify operation fails the output messages can be somewhat cryptic. The general
       form of the error message is:

        server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024 bit)
        error 24 at 1 depth lookup:invalid CA certificate

       The first line contains the name of the certificate being verified followed by the subject
       name of the certificate. The second line contains the error number and the depth. The
       depth is number of the certificate being verified when a problem was detected starting
       with zero for the certificate being verified itself then 1 for the CA that signed the
       certificate and so on. Finally a text version of the error number is presented.

       A partial list of the error codes and messages is shown below, this also includes the name
       of the error code as defined in the header file x509_vfy.h Some of the error codes are
       defined but never returned: these are described as "unused".

       X509_V_OK
           The operation was successful.

       X509_V_ERR_UNSPECIFIED
           Unspecified error; should not happen.

       X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT
           The issuer certificate of a looked up certificate could not be found. This normally
           means the list of trusted certificates is not complete.

       X509_V_ERR_UNABLE_TO_GET_CRL
           The CRL of a certificate could not be found.

       X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE
           The certificate signature could not be decrypted. This means that the actual signature
           value could not be determined rather than it not matching the expected value, this is
           only meaningful for RSA keys.

       X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE
           The CRL signature could not be decrypted: this means that the actual signature value
           could not be determined rather than it not matching the expected value. Unused.

       X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY
           The public key in the certificate SubjectPublicKeyInfo could not be read.

       X509_V_ERR_CERT_SIGNATURE_FAILURE
           The signature of the certificate is invalid.

       X509_V_ERR_CRL_SIGNATURE_FAILURE
           The signature of the certificate is invalid.

       X509_V_ERR_CERT_NOT_YET_VALID
           The certificate is not yet valid: the notBefore date is after the current time.

       X509_V_ERR_CERT_HAS_EXPIRED
           The certificate has expired: that is the notAfter date is before the current time.

       X509_V_ERR_CRL_NOT_YET_VALID
           The CRL is not yet valid.

       X509_V_ERR_CRL_HAS_EXPIRED
           The CRL has expired.

       X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD
           The certificate notBefore field contains an invalid time.

       X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD
           The certificate notAfter field contains an invalid time.

       X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD
           The CRL lastUpdate field contains an invalid time.

       X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD
           The CRL nextUpdate field contains an invalid time.

       X509_V_ERR_OUT_OF_MEM
           An error occurred trying to allocate memory. This should never happen.

       X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
           The passed certificate is self-signed and the same certificate cannot be found in the
           list of trusted certificates.

       X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN
           The certificate chain could be built up using the untrusted certificates but the root
           could not be found locally.

       X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY
           The issuer certificate could not be found: this occurs if the issuer certificate of an
           untrusted certificate cannot be found.

       X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE
           No signatures could be verified because the chain contains only one certificate and it
           is not self signed.

       X509_V_ERR_CERT_CHAIN_TOO_LONG
           The certificate chain length is greater than the supplied maximum depth. Unused.

       X509_V_ERR_CERT_REVOKED
           The certificate has been revoked.

       X509_V_ERR_INVALID_CA
           A CA certificate is invalid. Either it is not a CA or its extensions are not
           consistent with the supplied purpose.

       X509_V_ERR_PATH_LENGTH_EXCEEDED
           The basicConstraints pathlength parameter has been exceeded.

       X509_V_ERR_INVALID_PURPOSE
           The supplied certificate cannot be used for the specified purpose.

       X509_V_ERR_CERT_UNTRUSTED
           The root CA is not marked as trusted for the specified purpose.

       X509_V_ERR_CERT_REJECTED
           The root CA is marked to reject the specified purpose.

       X509_V_ERR_SUBJECT_ISSUER_MISMATCH
           Not used as of OpenSSL 1.1.0 as a result of the deprecation of the -issuer_checks
           option.

       X509_V_ERR_AKID_SKID_MISMATCH
           Not used as of OpenSSL 1.1.0 as a result of the deprecation of the -issuer_checks
           option.

       X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH
           Not used as of OpenSSL 1.1.0 as a result of the deprecation of the -issuer_checks
           option.

       X509_V_ERR_KEYUSAGE_NO_CERTSIGN
           Not used as of OpenSSL 1.1.0 as a result of the deprecation of the -issuer_checks
           option.

       X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER
           Unable to get CRL issuer certificate.

       X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION
           Unhandled critical extension.

       X509_V_ERR_KEYUSAGE_NO_CRL_SIGN
           Key usage does not include CRL signing.

       X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION
           Unhandled critical CRL extension.

       X509_V_ERR_INVALID_NON_CA
           Invalid non-CA certificate has CA markings.

       X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED
           Proxy path length constraint exceeded.

       X509_V_ERR_PROXY_SUBJECT_INVALID
           Proxy certificate subject is invalid.  It MUST be the same as the issuer with a single
           CN component added.

       X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE
           Key usage does not include digital signature.

       X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED
           Proxy certificates not allowed, please use -allow_proxy_certs.

       X509_V_ERR_INVALID_EXTENSION
           Invalid or inconsistent certificate extension.

       X509_V_ERR_INVALID_POLICY_EXTENSION
           Invalid or inconsistent certificate policy extension.

       X509_V_ERR_NO_EXPLICIT_POLICY
           No explicit policy.

       X509_V_ERR_DIFFERENT_CRL_SCOPE
           Different CRL scope.

       X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE
           Unsupported extension feature.

       X509_V_ERR_UNNESTED_RESOURCE
           RFC 3779 resource not subset of parent's resources.

       X509_V_ERR_PERMITTED_VIOLATION
           Permitted subtree violation.

       X509_V_ERR_EXCLUDED_VIOLATION
           Excluded subtree violation.

       X509_V_ERR_SUBTREE_MINMAX
           Name constraints minimum and maximum not supported.

       X509_V_ERR_APPLICATION_VERIFICATION
           Application verification failure. Unused.

       X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE
           Unsupported name constraint type.

       X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX
           Unsupported or invalid name constraint syntax.

       X509_V_ERR_UNSUPPORTED_NAME_SYNTAX
           Unsupported or invalid name syntax.

       X509_V_ERR_CRL_PATH_VALIDATION_ERROR
           CRL path validation error.

       X509_V_ERR_PATH_LOOP
           Path loop.

       X509_V_ERR_SUITE_B_INVALID_VERSION
           Suite B: certificate version invalid.

       X509_V_ERR_SUITE_B_INVALID_ALGORITHM
           Suite B: invalid public key algorithm.

       X509_V_ERR_SUITE_B_INVALID_CURVE
           Suite B: invalid ECC curve.

       X509_V_ERR_SUITE_B_INVALID_SIGNATURE_ALGORITHM
           Suite B: invalid signature algorithm.

       X509_V_ERR_SUITE_B_LOS_NOT_ALLOWED
           Suite B: curve not allowed for this LOS.

       X509_V_ERR_SUITE_B_CANNOT_SIGN_P_384_WITH_P_256
           Suite B: cannot sign P-384 with P-256.

       X509_V_ERR_HOSTNAME_MISMATCH
           Hostname mismatch.

       X509_V_ERR_EMAIL_MISMATCH
           Email address mismatch.

       X509_V_ERR_IP_ADDRESS_MISMATCH
           IP address mismatch.

       X509_V_ERR_DANE_NO_MATCH
           DANE TLSA authentication is enabled, but no TLSA records matched the certificate
           chain.  This error is only possible in s_client(1).

       X509_V_ERR_EE_KEY_TOO_SMALL
           EE certificate key too weak.

       X509_ERR_CA_KEY_TOO_SMALL
           CA certificate key too weak.

       X509_ERR_CA_MD_TOO_WEAK
           CA signature digest algorithm too weak.

       X509_V_ERR_INVALID_CALL
           nvalid certificate verification context.

       X509_V_ERR_STORE_LOOKUP
           Issuer certificate lookup error.

       X509_V_ERR_NO_VALID_SCTS
           Certificate Transparency required, but no valid SCTs found.

       X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION
           Proxy subject name violation.

       X509_V_ERR_OCSP_VERIFY_NEEDED
           Returned by the verify callback to indicate an OCSP verification is needed.

       X509_V_ERR_OCSP_VERIFY_FAILED
           Returned by the verify callback to indicate OCSP verification failed.

       X509_V_ERR_OCSP_CERT_UNKNOWN
           Returned by the verify callback to indicate that the certificate is not recognized by
           the OCSP responder.

BUGS

       Although the issuer checks are a considerable improvement over the old technique they
       still suffer from limitations in the underlying X509_LOOKUP API. One consequence of this
       is that trusted certificates with matching subject name must either appear in a file (as
       specified by the -CAfile option) or a directory (as specified by -CApath). If they occur
       in both then only the certificates in the file will be recognised.

       Previous versions of OpenSSL assume certificates with matching subject name are identical
       and mishandled them.

       Previous versions of this documentation swapped the meaning of the
       X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT and X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY
       error codes.

SEE ALSO

       x509(1)

HISTORY

       The -show_chain option was first added to OpenSSL 1.1.0.

       The -issuer_checks option is deprecated as of OpenSSL 1.1.0 and is silently ignored.

COPYRIGHT

       Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (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 <https://www.openssl.org/source/license.html>.