auth.m4, base.m4: Client authentication machinery.

If the server knows secrets for authenticating to a remote server, it
can use them.

diff --git a/auth.m4 b/auth.m4
index 074c6aa..93b25c0 100644 (file)
--- a/auth.m4
+++ b/auth.m4
@@ -33,6 +33,22 @@ m4_define(<:ALLOW_PLAINTEXT_AUTH_P:>,
 <:or {{match_ip {$sender_host_address}{+thishost}} \
       {and {{def:tls_cipher} {eq{$acl_c_mode}{submission}}}}}:>)
 
+m4_define(<:CLIENT_SECRETS_FILE:>, <:CONF_sysconf_dir/client-secrets:>)
+
+m4_define(<:CLIENT_SECRET_GET:>,
+<:${if exists {CLIENT_SECRETS_FILE} \
+       {${lookup {$domain} partial0-lsearch {CLIENT_SECRETS_FILE} \
+           {${extract {$1}{$value}$2$3}} \
+           {${lookup {$host} partial0-lsearch {CLIENT_SECRETS_FILE} \
+                     {${extract {$1}{$value}$2$3}} $3}}}} \
+       $3}:>)
+
+m4_define(<:CLIENT_SECRET_EXISTSP:>,
+<:CLIENT_SECRET_GET($1, {true}, {false}):>)
+
+m4_define(<:CLIENT_SECRET:>,
+<:CLIENT_SECRET_GET($1, {${expand:$value}}, fail):>)
+
 SECTION(auth)m4_dnl
 plain:
        driver = plaintext
@@ -41,6 +57,8 @@ plain:
        server_prompts = :
        server_condition = CHECK_PASSWD($auth2, $auth3)
        server_set_id = $auth2
+       client_condition = CLIENT_SECRET_EXISTSP(plain)
+       client_send = <; CLIENT_SECRET(plain)
 
 login:
        driver = plaintext
@@ -49,6 +67,17 @@ login:
        server_prompts = <; Username: ; Password:
        server_condition = CHECK_PASSWD($auth1, $auth2)
        server_set_id = $auth1
+       client_condition = CLIENT_SECRET_EXISTSP(login-passwd)
+       client_send = <; \
+               ; CLIENT_SECRET(login-name) \
+               ; CLIENT_SECRET(login-passwd)
+
+cram_md5:
+       driver = cram_md5
+       public_name = CRAM-MD5
+       client_condition = CLIENT_SECRET_EXISTSP(cram-md5-secret)
+       client_name = CLIENT_SECRET(cram-md5-name)
+       client_secret = CLIENT_SECRET(cram-md5-secret)
 
 DIVERT(null)
 ###--------------------------------------------------------------------------

diff --git a/base.m4 b/base.m4
index 6c2dc7b..523e475 100644 (file)
--- a/base.m4
+++ b/base.m4
@@ -351,7 +351,10 @@ SECTION(transports)m4_dnl
 ## `domains.conf' file.
 smtp:
        driver = smtp
+       hosts_try_auth = *
        hosts_require_tls = DOMKV(tls-peer-ca, {*}{})
+       hosts_require_auth = \
+               ${if bool {DOMKV(require-auth, {$value}{false})} {*}{}}
        tls_certificate = DOMKV(tls-certificate, {${expand:$value}}fail)
        tls_privatekey = DOMKV(tls-private-key, {${expand:$value}}fail)
        tls_verify_certificates = DOMKV(tls-peer-ca, {${expand:$value}}fail)