DKIM: disallow default acceptance of sha1 for verify

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index bb19e391552490de7e2217a12aa1a8bac782c77f..c8b999c9f6201f17bdccf6b9681828a96e57661f 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -15113,15 +15113,20 @@ to handle IPv6 literal addresses.
 
 
 .new
 
 
 .new

-.option dkim_verify_hashes main "string list" "sha256 : sha512 : sha1"
+.option dkim_verify_hashes main "string list" "sha256 : sha512"

 .cindex DKIM "selecting signature algorithms"
 This option gives a list of hash types which are acceptable in signatures,
 and an order of processing.
 Signatures with algorithms not in the list will be ignored.
 
 .cindex DKIM "selecting signature algorithms"
 This option gives a list of hash types which are acceptable in signatures,
 and an order of processing.
 Signatures with algorithms not in the list will be ignored.
 

-Note that the presence of sha1 violates RFC 8301.
-Signatures using the rsa-sha1 are however (as of writing) still common.
-The default inclusion of sha1 may be dropped in a future release.
+Acceptable values include:
+.code
+sha1
+sha256
+sha512
+.endd
+
+Note that the acceptance of sha1 violates RFC 8301.

 
 .option dkim_verify_keytypes main "string list" "ed25519 : rsa"
 This option gives a list of key types which are acceptable in signatures,
 
 .option dkim_verify_keytypes main "string list" "ed25519 : rsa"
 This option gives a list of key types which are acceptable in signatures,

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 079b5a1eecd7d006f38d1412a620703dfec2889c..45d126ccdf9bf9ee4c61f7320c153af9da0493f3 100644 (file)
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -14,6 +14,10 @@ JH/01 Avoid costly startup code when not strictly needed.  This reduces time
 
 JH/02 Early-pipelining support code is now included unless disabled in Makefile.
 
 
 JH/02 Early-pipelining support code is now included unless disabled in Makefile.
 

+JH/03 DKIM verification defaults no long accept sha1 hashes, to conform to
+      RFC 8301.  They can still be enabled, using the dkim_verify_hashes main
+      option.
+

 
 Exim version 4.93
 -----------------
 
 Exim version 4.93
 -----------------

diff --git a/src/src/globals.c b/src/src/globals.c
index 87ff2e65fca05feb2de42f7caed90671b8277555..b874c466909bb108a332ef54797d3513eb362910 100644 (file)
--- a/src/src/globals.c
+++ b/src/src/globals.c
@@ -831,7 +831,7 @@ void   *dkim_signatures              = NULL;
 uschar *dkim_signers             = NULL;
 uschar *dkim_signing_domain      = NULL;
 uschar *dkim_signing_selector    = NULL;
 uschar *dkim_signers             = NULL;
 uschar *dkim_signing_domain      = NULL;
 uschar *dkim_signing_selector    = NULL;

-uschar *dkim_verify_hashes       = US"sha256:sha512:sha1";
+uschar *dkim_verify_hashes       = US"sha256:sha512";

 uschar *dkim_verify_keytypes     = US"ed25519:rsa";
 BOOL   dkim_verify_minimal      = FALSE;
 uschar *dkim_verify_overall      = NULL;
 uschar *dkim_verify_keytypes     = US"ed25519:rsa";
 BOOL   dkim_verify_minimal      = FALSE;
 uschar *dkim_verify_overall      = NULL;

diff --git a/test/confs/4500 b/test/confs/4500
index 502de4a1972dcecab3d0523ac126b44f503571c1..c7335327e3861f60fbd25492537debe739c8727c 100644 (file)
--- a/test/confs/4500
+++ b/test/confs/4500
@@ -13,6 +13,7 @@ acl_smtp_dkim = check_dkim
 acl_smtp_data = check_data
 
 log_selector = +dkim_verbose
 acl_smtp_data = check_data
 
 log_selector = +dkim_verbose

+dkim_verify_hashes = sha256 : sha512 : sha1

 
 queue_only
 queue_run_in_order
 
 queue_only
 queue_run_in_order

diff --git a/test/stderr/4507 b/test/stderr/4507
index 48d4d9fa9caff10c1ccb031f80d76e05589ad2e4..1c45d0955e60de73f5f0ddeb3fd41e73b747be11 100644 (file)
--- a/test/stderr/4507
+++ b/test/stderr/4507
@@ -9,22 +9,22 @@
 >>> host in helo_try_verify_hosts? no (option unset)
 >>> host in helo_accept_junk_hosts? no (option unset)
 >>> xxx in helo_lookup_domains? no (end of list)
 >>> host in helo_try_verify_hosts? no (option unset)
 >>> host in helo_accept_junk_hosts? no (option unset)
 >>> xxx in helo_lookup_domains? no (end of list)

->>> processing "accept" (TESTSUITE/test-config 43)
+>>> processing "accept" (TESTSUITE/test-config 44)

 >>> accept: condition test succeeded in inline ACL
 >>> end of inline ACL: ACCEPT
 >>> host in ignore_fromline_hosts? no (option unset)
 >>> using ACL "check_dkim"
 >>> accept: condition test succeeded in inline ACL
 >>> end of inline ACL: ACCEPT
 >>> host in ignore_fromline_hosts? no (option unset)
 >>> using ACL "check_dkim"

->>> processing "warn" (TESTSUITE/test-config 34)
+>>> processing "warn" (TESTSUITE/test-config 35)

 >>> check logwrite = signer: $dkim_cur_signer bits: $dkim_key_length
 >>>                = signer: test.ex bits: 1024
 LOG: 10HmaX-0005vi-00 signer: test.ex bits: 1024
 >>> warn: condition test succeeded in ACL "check_dkim"
 >>> check logwrite = signer: $dkim_cur_signer bits: $dkim_key_length
 >>>                = signer: test.ex bits: 1024
 LOG: 10HmaX-0005vi-00 signer: test.ex bits: 1024
 >>> warn: condition test succeeded in ACL "check_dkim"

->>> processing "accept" (TESTSUITE/test-config 37)
+>>> processing "accept" (TESTSUITE/test-config 38)

 >>> accept: condition test succeeded in ACL "check_dkim"
 >>> end of ACL "check_dkim": ACCEPT
 LOG: 10HmaX-0005vi-00 DKIM: d=test.ex s=sel c=simple/simple a=rsa-sha1 b=1024 [verification succeeded]
 >>> using ACL "check_data"
 >>> accept: condition test succeeded in ACL "check_dkim"
 >>> end of ACL "check_dkim": ACCEPT
 LOG: 10HmaX-0005vi-00 DKIM: d=test.ex s=sel c=simple/simple a=rsa-sha1 b=1024 [verification succeeded]
 >>> using ACL "check_data"

->>> processing "accept" (TESTSUITE/test-config 41)
+>>> processing "accept" (TESTSUITE/test-config 42)

 >>> check logwrite = ${authresults {$primary_hostname}}
 >>>                = Authentication-Results: myhost.test.ex;
 >>>    dkim=pass header.d=test.ex header.s=sel header.a=rsa-sha1
 >>> check logwrite = ${authresults {$primary_hostname}}
 >>>                = Authentication-Results: myhost.test.ex;
 >>>    dkim=pass header.d=test.ex header.s=sel header.a=rsa-sha1