Support use of system default CA bundle

[users/heiko/exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 8b1a17b26f91fc2339bde898e3c56b403180817c..89fb5841e9cf392238b53a545f019dc75a61f416 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -13562,8 +13562,9 @@ This option defines the ACL that is run after an SMTP DATA command has been
 processed and the message itself has been received, but before the final
 acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
 
 processed and the message itself has been received, but before the final
 acknowledgment is sent. See chapter &<<CHAPACL>>& for further details.
 

-.option acl_smtp_data_prdr main string&!! unset
-.cindex "DATA" "ACL for"
+.option acl_smtp_data_prdr main string&!! accept
+.cindex "PRDR" "ACL for"
+.cindex "DATA" "PRDR ACL for"

 .cindex "&ACL;" "PRDR-related"
 .cindex "&ACL;" "per-user data processing"
 This option defines the ACL that,
 .cindex "&ACL;" "PRDR-related"
 .cindex "&ACL;" "per-user data processing"
 This option defines the ACL that,


@@ -16496,21 +16497,31 @@ See &%tls_verify_hosts%& below.
 .option tls_verify_certificates main string&!! unset
 .cindex "TLS" "client certificate verification"
 .cindex "certificate" "verification of client"
 .option tls_verify_certificates main string&!! unset
 .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 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.

 
 These certificates should be for the certificate authorities trusted, rather
 than the public cert of individual clients.  With both OpenSSL and GnuTLS, if
 the value is a file then the certificates are sent by Exim as a server to
 connecting clients, defining the list of accepted certificate authorities.
 Thus the values defined should be considered public data.  To avoid this,
 
 These certificates should be for the certificate authorities trusted, rather
 than the public cert of individual clients.  With both OpenSSL and GnuTLS, if
 the value is a file then the certificates are sent by Exim as a server to
 connecting clients, defining the list of accepted certificate authorities.
 Thus the values defined should be considered public data.  To avoid this,

-use OpenSSL with a directory.
+use the explicit directory version.

 
 See &<<SECTtlssni>>& for discussion of when this option might be re-expanded.
 
 
 See &<<SECTtlssni>>& for discussion of when this option might be re-expanded.
 


@@ -23175,11 +23186,12 @@ connects. If authentication fails, Exim will try to transfer the message
 unauthenticated. See also &%hosts_require_auth%&, and chapter
 &<<CHAPSMTPAUTH>>& for details of authentication.
 
 unauthenticated. See also &%hosts_require_auth%&, and chapter
 &<<CHAPSMTPAUTH>>& for details of authentication.
 

-.option hosts_try_prdr smtp "host list&!!" unset
+.option hosts_try_prdr smtp "host list&!!" *

 .cindex "PRDR" "enabling, optional in client"
 This option provides a list of servers to which, provided they announce
 PRDR support, Exim will attempt to negotiate PRDR
 for multi-recipient messages.
 .cindex "PRDR" "enabling, optional in client"
 This option provides a list of servers to which, provided they announce
 PRDR support, Exim will attempt to negotiate PRDR
 for multi-recipient messages.

+The option can usually be left as default.

 
 .option interface smtp "string list&!!" unset
 .cindex "bind IP address"
 
 .option interface smtp "string list&!!" unset
 .cindex "bind IP address"


@@ -23237,7 +23249,7 @@ so can cause parallel connections to the same host if &%remote_max_parallel%&
 permits this.
 
 
 permits this.
 
 

-.option multi_domain smtp boolean true
+.option multi_domain smtp boolean&!! true

 .vindex "&$domain$&"
 When this option is set, the &(smtp)& transport can handle a number of
 addresses containing a mixture of different domains provided they all resolve
 .vindex "&$domain$&"
 When this option is set, the &(smtp)& transport can handle a number of
 addresses containing a mixture of different domains provided they all resolve


@@ -23246,6 +23258,9 @@ handling only one domain at a time. This is useful if you want to use
 &$domain$& in an expansion for the transport, because it is set only when there
 is a single domain involved in a remote delivery.
 
 &$domain$& in an expansion for the transport, because it is set only when there
 is a single domain involved in a remote delivery.
 

+It is expanded per-address and can depend on any of
+&$address_data$&, &$domain_data$&, &$local_part_data$&,
+&$host$&, &$host_address$& and &$host_port$&.

 
 .option port smtp string&!! "see below"
 .cindex "port" "sending TCP/IP"
 
 .option port smtp string&!! "see below"
 .cindex "port" "sending TCP/IP"


@@ -23281,7 +23296,7 @@ connecting, as an outbound SSL-on-connect, instead of using STARTTLS to upgrade.
 The Internet standards bodies strongly discourage use of this mode.
 
 
 The Internet standards bodies strongly discourage use of this mode.
 
 

-.option retry_include_ip_address smtp boolean true
+.option retry_include_ip_address smtp boolean&!! true

 Exim normally includes both the host name and the IP address in the key it
 constructs for indexing retry data after a temporary delivery failure. This
 means that when one of several IP addresses for a host is failing, it gets
 Exim normally includes both the host name and the IP address in the key it
 constructs for indexing retry data after a temporary delivery failure. This
 means that when one of several IP addresses for a host is failing, it gets


@@ -23291,9 +23306,8 @@ addresses is not affected.
 However, in some dialup environments hosts are assigned a different IP address
 each time they connect. In this situation the use of the IP address as part of
 the retry key leads to undesirable behaviour. Setting this option false causes
 However, in some dialup environments hosts are assigned a different IP address
 each time they connect. In this situation the use of the IP address as part of
 the retry key leads to undesirable behaviour. Setting this option false causes

-Exim to use only the host name. This should normally be done on a separate
-instance of the &(smtp)& transport, set up specially to handle the dialup
-hosts.
+Exim to use only the host name.
+Since it is expanded it can be made to depend on the host or domain.

 
 
 .option serialize_hosts smtp "host list&!!" unset
 
 
 .option serialize_hosts smtp "host list&!!" unset


@@ -23431,7 +23445,7 @@ unknown state), opens a new one to the same host, and then tries the delivery
 in clear.
 
 
 in clear.
 
 

-.option tls_try_verify_hosts smtp "host list&!! unset
+.option tls_try_verify_hosts smtp "host list&!!" unset

 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which, on encrypted connections,
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which, on encrypted connections,


@@ -23439,25 +23453,47 @@ certificate verification will be tried but need not succeed.
 The &%tls_verify_certificates%& option must also be set.
 Note that unless the host is in this list
 TLS connections will be denied to hosts using self-signed certificates
 The &%tls_verify_certificates%& option must also be set.
 Note that unless the host is in this list
 TLS connections will be denied to hosts using self-signed certificates

-when &%tls_verify_certificates%& is set.
+when &%tls_verify_certificates%& is matched.

 The &$tls_out_certificate_verified$& variable is set when
 certificate verification succeeds.
 
 
 The &$tls_out_certificate_verified$& variable is set when
 certificate verification succeeds.
 
 

+.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&!! unset
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 .vindex "&$host$&"
 .vindex "&$host_address$&"
 .option tls_verify_certificates smtp string&!! unset
 .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 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
+either by file or directory
+are added to those given by the system default location.
+

 The values of &$host$& and
 &$host_address$& are set to the name and address of the server during the
 expansion of this option. See chapter &<<CHAPTLS>>& for details of TLS.
 The values of &$host$& and
 &$host_address$& are set to the name and address of the server during the
 expansion of this option. See chapter &<<CHAPTLS>>& for details of TLS.


@@ -23467,7 +23503,7 @@ if neither tls_verify_hosts nor tls_try_verify_hosts are set
 and certificate verification fails the TLS connection is closed.
 
 
 and certificate verification fails the TLS connection is closed.
 
 

-.option tls_verify_hosts smtp "host list&!! unset
+.option tls_verify_hosts smtp "host list&!!" unset

 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which. on encrypted connections,
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which. on encrypted connections,


@@ -25939,8 +25975,9 @@ include files and libraries for GnuTLS can be found.
 There are some differences in usage when using GnuTLS instead of OpenSSL:
 
 .ilist
 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.
 (for later versions, or OpenSSL, it can be either).
 .next
 The default value for &%tls_dhparam%& differs for historical reasons.


@@ -26292,8 +26329,10 @@ session with a client, you must set either &%tls_verify_hosts%& or
 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
 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_certificates%&.
 
 A file can contain multiple certificates, concatenated end to end. If a


@@ -26453,9 +26492,13 @@ if it requests it. If the server is Exim, it will request a certificate only if
 &%tls_verify_hosts%& or &%tls_try_verify_hosts%& matches the client.
 
 If the &%tls_verify_certificates%& option is set on the &(smtp)& transport, it
 &%tls_verify_hosts%& or &%tls_try_verify_hosts%& matches the client.
 
 If the &%tls_verify_certificates%& option is set on the &(smtp)& transport, it

+specified 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,
 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
 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


@@ -26924,6 +26967,7 @@ This ACL is evaluated after &%acl_smtp_dkim%& but before &%acl_smtp_data%&.
 
 
 .section "The SMTP PRDR ACL" "SECTPRDRACL"
 
 
 .section "The SMTP PRDR ACL" "SECTPRDRACL"

+.cindex "PRDR" "ACL for"

 .oindex "&%prdr_enable%&"
 The &%acl_smtp_data_prdr%& ACL is available only when Exim is compiled
 with PRDR support enabled (which is the default).
 .oindex "&%prdr_enable%&"
 The &%acl_smtp_data_prdr%& ACL is available only when Exim is compiled
 with PRDR support enabled (which is the default).


@@ -26932,8 +26976,9 @@ client and server for a message, and more than one recipient
 has been accepted.
 
 The ACL test specfied by &%acl_smtp_data_prdr%& happens after a message
 has been accepted.
 
 The ACL test specfied by &%acl_smtp_data_prdr%& happens after a message

-has been recieved, and is executed for each recipient of the message.
-The test may accept or deny for inividual recipients.
+has been recieved, and is executed once for each recipient of the message
+with &$local_part$& and &$domain$& valid.
+The test may accept, defer or deny for inividual recipients.

 The &%acl_smtp_data%& will still be called after this ACL and
 can reject the message overall, even if this ACL has accepted it
 for some or all recipients.
 The &%acl_smtp_data%& will still be called after this ACL and
 can reject the message overall, even if this ACL has accepted it
 for some or all recipients.