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-rw-r--r--doc/doc-txt/ChangeLog3
-rw-r--r--src/src/pdkim/pdkim.c33
-rw-r--r--src/src/pdkim/pdkim.h15
-rw-r--r--test/dnszones-src/db.test.ex6
-rw-r--r--test/log/45003
-rw-r--r--test/log/45063
-rw-r--r--test/scripts/4500-DKIM/450034
-rw-r--r--test/scripts/4500-DKIM/450635
-rw-r--r--test/stderr/45201
9 files changed, 120 insertions, 13 deletions
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 0b4076c20..ecb6b33a9 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -138,6 +138,9 @@ JH/21 Bug 2151: Avoid using SIZE on the MAIL for a callout verify, on any but
JH/22 Retire historical build files to an "unsupported" subdir. These are
defined as "ones for which we have no current evidence of testing".
+JH/23 DKIM: enforce the DNS pubkey record "h" permitted-hashes optional field,
+ if present. Previously it was ignored.
+
Exim version 4.89
-----------------
diff --git a/src/src/pdkim/pdkim.c b/src/src/pdkim/pdkim.c
index d41b60f13..d289ec7a3 100644
--- a/src/src/pdkim/pdkim.c
+++ b/src/src/pdkim/pdkim.c
@@ -132,6 +132,7 @@ switch(ext_status)
{
case PDKIM_VERIFY_FAIL_BODY: return "PDKIM_VERIFY_FAIL_BODY";
case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE";
+ case PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH: return "PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH";
case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE";
case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE";
case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: return "PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD";
@@ -644,12 +645,8 @@ for (p = raw_record; ; p++)
case 'v':
pub->version = string_copy(cur_val); break;
case 'h':
+ pub->hashes = string_copy(cur_val); break;
case 'k':
-/* This field appears to never be used. Also, unclear why
-a 'k' (key-type_ would go in this field name. There is a field
-"keytype", also never used.
- pub->hashes = string_copy(cur_val);
-*/
break;
case 'g':
pub->granularity = string_copy(cur_val); break;
@@ -682,7 +679,11 @@ a 'k' (key-type_ would go in this field name. There is a field
/* Set fallback defaults */
if (!pub->version ) pub->version = string_copy(PDKIM_PUB_RECORD_VERSION);
-else if (Ustrcmp(pub->version, PDKIM_PUB_RECORD_VERSION) != 0) return NULL;
+else if (Ustrcmp(pub->version, PDKIM_PUB_RECORD_VERSION) != 0)
+ {
+ DEBUG(D_acl) debug_printf(" Bad v= field\n");
+ return NULL;
+ }
if (!pub->granularity) pub->granularity = string_copy(US"*");
/*
@@ -694,6 +695,7 @@ if (!pub->srvtype ) pub->srvtype = string_copy(US"*");
if (pub->key.data)
return pub;
+DEBUG(D_acl) debug_printf(" Missing p= field\n");
return NULL;
}
@@ -1631,6 +1633,25 @@ while (sig)
if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx, err)))
goto NEXT_VERIFY;
+ /* If the pubkey limits to a list of specific hashes, ignore sigs that
+ do not have the hash part of the sig algorithm matching */
+
+ if (sig->pubkey->hashes)
+ {
+ const uschar * list = sig->pubkey->hashes, * ele;
+ int sep = ':';
+ while ((ele = string_nextinlist(&list, &sep, NULL, 0)))
+ if (Ustrcmp(ele, pdkim_algos[sig->algo] + 4) == 0) break;
+ if (!ele)
+ {
+ DEBUG(D_acl) debug_printf("pubkey h=%s vs sig a=%s\n",
+ sig->pubkey->hashes, pdkim_algos[sig->algo]);
+ sig->verify_status = PDKIM_VERIFY_FAIL;
+ sig->verify_ext_status = PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH;
+ goto NEXT_VERIFY;
+ }
+ }
+
/* Check the signature */
if ((*err = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sighash)))
{
diff --git a/src/src/pdkim/pdkim.h b/src/src/pdkim/pdkim.h
index 78e3c3c8b..9899356d5 100644
--- a/src/src/pdkim/pdkim.h
+++ b/src/src/pdkim/pdkim.h
@@ -51,12 +51,13 @@
#define PDKIM_VERIFY_FAIL_BODY 1
#define PDKIM_VERIFY_FAIL_MESSAGE 2
-#define PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE 3
-#define PDKIM_VERIFY_INVALID_BUFFER_SIZE 4
-#define PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD 5
-#define PDKIM_VERIFY_INVALID_PUBKEY_IMPORT 6
-#define PDKIM_VERIFY_INVALID_SIGNATURE_ERROR 7
-#define PDKIM_VERIFY_INVALID_DKIM_VERSION 8
+#define PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH 3
+#define PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE 4
+#define PDKIM_VERIFY_INVALID_BUFFER_SIZE 5
+#define PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD 6
+#define PDKIM_VERIFY_INVALID_PUBKEY_IMPORT 7
+#define PDKIM_VERIFY_INVALID_SIGNATURE_ERROR 8
+#define PDKIM_VERIFY_INVALID_DKIM_VERSION 9
/* -------------------------------------------------------------------------- */
/* Some parameter values */
@@ -100,8 +101,8 @@ typedef struct pdkim_pubkey {
uschar *version; /* v= */
uschar *granularity; /* g= */
-#ifdef notdef
uschar *hashes; /* h= */
+#ifdef notdef
uschar *keytype; /* k= */
#endif
uschar *srvtype; /* s= */
diff --git a/test/dnszones-src/db.test.ex b/test/dnszones-src/db.test.ex
index f7c9e313b..73db57f9c 100644
--- a/test/dnszones-src/db.test.ex
+++ b/test/dnszones-src/db.test.ex
@@ -491,13 +491,19 @@ DELAY=1500 delay1500 A HOSTIPV4
; openssl rsa -in aux-fixed/dkim/dkim.private -out /dev/stdout -pubout -outform PEM
;
; Deliberate bad version, having extra backslashes
+; sha256-hash-only version.... appears to be too long, gets truncated
;
; Another, 512-bit (with a Notes field)
+; 512 requiring sha1 hash
+; 512 requiring sha256 hash
;
sel._domainkey TXT "v=DKIM1; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDXRFf+VhT+lCgFhhSkinZKcFNeRzjYdW8vT29Rbb3NadvTFwAd+cVLPFwZL8H5tUD/7JbUPqNTCPxmpgIL+V5T4tEZMorHatvvUM2qfcpQ45IfsZ+YdhbIiAslHCpy4xNxIR3zylgqRUF4+Dtsaqy3a5LhwMiKCLrnzhXk1F1hxwIDAQAB"
sel_bad._domainkey TXT "v=DKIM1\; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDXRFf+VhT+lCgFhhSkinZKcFNeRzjYdW8vT29Rbb3NadvTFwAd+cVLPFwZL8H5tUD/7JbUPqNTCPxmpgIL+V5T4tEZMorHatvvUM2qfcpQ45IfsZ+YdhbIiAslHCpy4xNxIR3zylgqRUF4+Dtsaqy3a5LhwMiKCLrnzhXk1F1hxwIDAQAB"
+sel_sha256._domainkey TXT "v=DKIM1; h=sha256; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDXRFf+VhT+lCgFhhSkinZKcFNeRzjYdW8vT29Rbb3NadvTFwAd+cVLPFwZL8H5tUD/7JbUPqNTCPxmpgIL+V5T4tEZMorHatvvUM2qfcpQ45IfsZ+YdhbIiAslHCpy4xNxIR3zylgqRUF4+Dtsaqy3a5LhwMiKCLrnzhXk1F1hxwIDAQAB"
ses._domainkey TXT "v=DKIM1; n=halfkilo; p=MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAL6eAQxd9didJ0/+05iDwJOqT6ly826Vi8aGPecsBiYK5/tAT97fxXk+dPWMZp9kQxtknEzYjYjAydzf+HQ2yJMCAwEAAQ=="
+ses_sha1._domainkey TXT "v=DKIM1; h=sha1; p=MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAL6eAQxd9didJ0/+05iDwJOqT6ly826Vi8aGPecsBiYK5/tAT97fxXk+dPWMZp9kQxtknEzYjYjAydzf+HQ2yJMCAwEAAQ=="
+ses_sha256._domainkey TXT "v=DKIM1; h=sha256; p=MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAL6eAQxd9didJ0/+05iDwJOqT6ly826Vi8aGPecsBiYK5/tAT97fxXk+dPWMZp9kQxtknEzYjYjAydzf+HQ2yJMCAwEAAQ=="
; End
diff --git a/test/log/4500 b/test/log/4500
index 0e0f8400d..ec8ef088e 100644
--- a/test/log/4500
+++ b/test/log/4500
@@ -10,3 +10,6 @@
1999-03-02 09:44:33 10HmaZ-0005vi-00 DKIM: d=test.ex s=sel c=simple/simple a=rsa-sha256 b=1024 [verification succeeded]
1999-03-02 09:44:33 10HmaZ-0005vi-00 signer: test.ex bits: 1024
1999-03-02 09:44:33 10HmaZ-0005vi-00 <= CALLER@bloggs.com H=(xxx) [127.0.0.1] P=smtp S=sss id=qwerty1234@disco-zombie.net
+1999-03-02 09:44:33 10HmbA-0005vi-00 DKIM: d=test.ex s=ses_sha1 c=simple/simple a=rsa-sha1 b=512 [verification succeeded]
+1999-03-02 09:44:33 10HmbA-0005vi-00 signer: test.ex bits: 512
+1999-03-02 09:44:33 10HmbA-0005vi-00 <= CALLER@bloggs.com H=(xxx) [127.0.0.1] P=smtp S=sss id=qwerty1234@disco-zombie.net
diff --git a/test/log/4506 b/test/log/4506
index fb0f22567..027169df0 100644
--- a/test/log/4506
+++ b/test/log/4506
@@ -13,3 +13,6 @@
1999-03-02 09:44:33 10HmbA-0005vi-00 DKIM: validation error: RSA_LONG_LINE
1999-03-02 09:44:33 10HmbA-0005vi-00 DKIM: Error during validation, disabling signature verification: RSA_LONG_LINE
1999-03-02 09:44:33 10HmbA-0005vi-00 <= CALLER@bloggs.com H=(xxx) [127.0.0.1] P=smtp S=sss id=qwerty1234@disco-zombie.net
+1999-03-02 09:44:33 10HmbB-0005vi-00 DKIM: d=test.ex s=ses_sha256 c=simple/simple a=rsa-sha1 b=512 [verification failed - unspecified reason]
+1999-03-02 09:44:33 10HmbB-0005vi-00 signer: test.ex bits: 512
+1999-03-02 09:44:33 10HmbB-0005vi-00 <= CALLER@bloggs.com H=(xxx) [127.0.0.1] P=smtp S=sss id=qwerty1234@disco-zombie.net
diff --git a/test/scripts/4500-DKIM/4500 b/test/scripts/4500-DKIM/4500
index 6728b141d..6b3ff5fcf 100644
--- a/test/scripts/4500-DKIM/4500
+++ b/test/scripts/4500-DKIM/4500
@@ -101,6 +101,40 @@ QUIT
****
#
#
+# This should pass. The pubkey dns decord has a additional sha1-only h= field
+#
+# - sha1, 512b
+# Mail original in aux-fixed/4500.msg1.txt
+# Sig generated by: perl aux-fixed/dkim/sign.pl --keyfile=aux-fixed/dkim/dkim512.private \
+# --method=simple/simple --selector=ses_sha1 < aux-fixed/4500.msg1.txt
+client 127.0.0.1 PORT_D
+??? 220
+HELO xxx
+??? 250
+MAIL FROM:<CALLER@bloggs.com>
+??? 250
+RCPT TO:<a@test.ex>
+??? 250
+DATA
+??? 354
+DKIM-Signature: v=1; a=rsa-sha1; c=simple/simple; d=test.ex; h=from:to
+ :date:message-id:subject; s=ses_sha1; bh=OB9dZVu7+5/ufs3TH9leIcE
+ pXSo=; b=hG14R3Eb/f13Pw6J0LmovHAL01KHVmVrTZ7KJrqieYTQemUaseoU2pB
+ 7/g8NUwG/AsYoaw3gaAK8PqxSk2lcIQ==
+From: mrgus@text.ex
+To: bakawolf@yahoo.com
+Date: Thu, 19 Nov 2015 17:00:07 -0700
+Message-ID: <qwerty1234@disco-zombie.net>
+Subject: simple test
+
+This is a simple test.
+.
+??? 250
+QUIT
+??? 221
+****
+#
+#
killdaemon
no_stdout_check
no_msglog_check
diff --git a/test/scripts/4500-DKIM/4506 b/test/scripts/4500-DKIM/4506
index 6eb81cc16..e8d7c41f0 100644
--- a/test/scripts/4500-DKIM/4506
+++ b/test/scripts/4500-DKIM/4506
@@ -134,6 +134,41 @@ QUIT
****
#
#
+# This should fail as the sig on the mail uses sha1 but the dns record requires sha256
+#
+# - sha256, 512b
+# Mail original in aux-fixed/4500.msg1.txt
+# Sig generated by: perl aux-fixed/dkim/sign.pl --keyfile=aux-fixed/dkim/dkim512.private \
+# --method=simple/simple --selector=ses_sha1 < aux-fixed/4500.msg1.txt
+# and then modifying the s= manually
+client 127.0.0.1 PORT_D
+??? 220
+HELO xxx
+??? 250
+MAIL FROM:<CALLER@bloggs.com>
+??? 250
+RCPT TO:<a@test.ex>
+??? 250
+DATA
+??? 354
+DKIM-Signature: v=1; a=rsa-sha1; c=simple/simple; d=test.ex; h=from:to
+ :date:message-id:subject; s=ses_sha256; bh=OB9dZVu7+5/ufs3TH9leIcE
+ pXSo=; b=hG14R3Eb/f13Pw6J0LmovHAL01KHVmVrTZ7KJrqieYTQemUaseoU2pB
+ 7/g8NUwG/AsYoaw3gaAK8PqxSk2lcIQ==
+From: mrgus@text.ex
+To: bakawolf@yahoo.com
+Date: Thu, 19 Nov 2015 17:00:07 -0700
+Message-ID: <qwerty1234@disco-zombie.net>
+Subject: simple test
+
+This is a simple test.
+.
+??? 250
+QUIT
+??? 221
+****
+#
+#
killdaemon
no_stdout_check
no_msglog_check
diff --git a/test/stderr/4520 b/test/stderr/4520
index c1bafcdcc..fc64a9e93 100644
--- a/test/stderr/4520
+++ b/test/stderr/4520
@@ -28,6 +28,7 @@ PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Raw record: v=DKIM1\;{SP}p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDXRFf+VhT+lCgFhhSkinZKcFNeRzjYdW8vT29Rbb3NadvTFwAd+cVLPFwZL8H5tUD/7JbUPqNTCPxmpgIL+V5T4tEZMorHatvvUM2qfcpQ45IfsZ+YdhbIiAslHCpy4xNxIR3zylgqRUF4+Dtsaqy3a5LhwMiKCLrnzhXk1F1hxwIDAQAB
v=DKIM1\
p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDXRFf+VhT+lCgFhhSkinZKcFNeRzjYdW8vT29Rbb3NadvTFwAd+cVLPFwZL8H5tUD/7JbUPqNTCPxmpgIL+V5T4tEZMorHatvvUM2qfcpQ45IfsZ+YdhbIiAslHCpy4xNxIR3zylgqRUF4+Dtsaqy3a5LhwMiKCLrnzhXk1F1hxwIDAQAB
+ Bad v= field
Error while parsing public key record
WARNING: bad dkim key in dns
PDKIM (finished checking verify key)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 06:44:32 +0000