From: Mark Wooding <mdw@distorted.org.uk>
Date: Tue, 18 Mar 2014 16:32:42 +0000 (+0000)
Subject: auth.m4, base.m4: Client authentication machinery.
X-Git-Url: https://git.distorted.org.uk/~mdw/exim-config/commitdiff_plain/ae9744ce099209f94e7a5b73e47d99af7e712163

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
--- 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
--- 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)