See &%tls_verify_hosts%& below.
-.option tls_verify_certificates main string&!! unset
+.option tls_verify_certificates main string&!! system
.cindex "TLS" "client certificate verification"
.cindex "certificate" "verification of client"
-The value of this option is expanded, and must then be the absolute path to
-a file containing permitted certificates for clients that
-match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&. Alternatively, if you
-are using either GnuTLS version 3.3.6 (or later) or OpenSSL,
-you can set &%tls_verify_certificates%& to the name of a
-directory containing certificate files.
-For earlier versions of GnuTLS
-the option must be set to the name of a single file.
+The value of this option is expanded, and must then be either the
+word "system"
+or the absolute path to
+a file or directory containing permitted certificates for clients that
+match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&.
+
+The "system" value for the option will use a
+system default location compiled into the SSL library.
+This is not available for GnuTLS versions preceding 3.0.20,
+and will be taken as empty; an explicit location
+must be specified.
+
+The use of a directory for the option value is not avilable for GnuTLS versions
+preceding 3.3.6 and a single file must be used.
+
+With OpenSSL the certificates specified
+explicitly
+either by file or directory
+are added to those given by the system default location.
With OpenSSL the certificates specified
explicitly
in clear.
-.option tls_try_verify_hosts smtp "host list&!!" unset
+.option tls_try_verify_hosts smtp "host list&!!" *
.cindex "TLS" "server certificate verification"
.cindex "certificate" "verification of server"
This option gives a list of hosts for which, on encrypted connections,
certificate verification succeeds.
-.option tls_verify_certificates smtp string&!! unset
+.option tls_verify_cert_hostnames smtp "host list&!!" *
+.cindex "TLS" "server certificate hostname verification"
+.cindex "certificate" "verification of server"
+This option give a list of hosts for which,
+while verifying the server certificate,
+checks will be included on the host name
+(note that this will generally be the result of a DNS MX lookup)
+versus Subject and Subject-Alternate-Name fields. Wildcard names are permitted
+limited to being the initial component of a 3-or-more component FQDN.
+
+There is no equivalent checking on client certificates.
+
+
+.option tls_verify_certificates smtp string&!! system
.cindex "TLS" "server certificate verification"
.cindex "certificate" "verification of server"
.vindex "&$host$&"
.vindex "&$host_address$&"
-The value of this option must be the absolute path to a file containing
-permitted server certificates, for use when setting up an encrypted connection.
-Alternatively,
-if you are using either GnuTLS version 3.3.6 (or later) or OpenSSL,
-you can set
-&%tls_verify_certificates%& to the name of a directory containing certificate
-files.
-For earlier versions of GnuTLS the option must be set to the name of a
-single file.
+The value of this option must be either the
+word "system"
+or the absolute path to
+a file or directory containing permitted certificates for servers,
+for use when setting up an encrypted connection.
+
+The "system" value for the option will use a location compiled into the SSL library.
+This is not available for GnuTLS versions preceding 3.0.20; a value of "system"
+is taken as empty and an explicit location
+must be specified.
+
+The use of a directory for the option value is not avilable for GnuTLS versions
+preceding 3.3.6 and a single file must be used.
With OpenSSL the certificates specified
explicitly
For back-compatability,
if neither tls_verify_hosts nor tls_try_verify_hosts are set
+(a single-colon empty list counts as being set)
and certificate verification fails the TLS connection is closed.
There are some differences in usage when using GnuTLS instead of OpenSSL:
.ilist
-The &%tls_verify_certificates%& option must contain the name of a file, not the
-name of a directory for GnuTLS versions before 3.3.6
+The &%tls_verify_certificates%& option
+cannot be the path of a directory
+for GnuTLS versions before 3.3.6
(for later versions, or OpenSSL, it can be either).
.next
The default value for &%tls_dhparam%& differs for historical reasons.
apply to all TLS connections. For any host that matches one of these options,
Exim requests a certificate as part of the setup of the TLS session. The
contents of the certificate are verified by comparing it with a list of
-expected certificates. These must be available in a file or,
-for OpenSSL only (not GnuTLS), a directory, identified by
+expected certificates.
+These may be the system default set (depending on library version),
+an explicit file or,
+depending on library version, a directory, identified by
&%tls_verify_certificates%&.
A file can contain multiple certificates, concatenated end to end. If a
&%tls_verify_hosts%& or &%tls_try_verify_hosts%& matches the client.
If the &%tls_verify_certificates%& option is set on the &(smtp)& transport, it
+specifies a collection of expected server certificates.
+These may be the system default set (depeding on library version),
+a file or,
+depnding on liibrary version, a directory,
must name a file or,
-for OpenSSL only (not GnuTLS), a directory, that contains a collection of
-expected server certificates. The client verifies the server's certificate
+for OpenSSL only (not GnuTLS), a directory.
+The client verifies the server's certificate
against this collection, taking into account any revoked certificates that are
in the list defined by &%tls_crl%&.
Failure to verify fails the TLS connection unless either of the
git://git.exim.org / exim.git / blobdiff