Follow CNAME chains only one step. Bug 2264

[users/jgh/exim.git] / src / src / dkim.c

diff --git a/src/src/dkim.c b/src/src/dkim.c
index f7b9ee0d18905d7cf9c8d213cdd69718b2c3eef6..317f6e50dd2460551386528998f9c613e81f8cf9 100644 (file)
--- a/src/src/dkim.c
+++ b/src/src/dkim.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 

-/* Copyright (c) University of Cambridge, 1995 - 2017 */
+/* Copyright (c) University of Cambridge, 1995 - 2018 */

 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Code for DKIM support. Other DKIM relevant code is in
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Code for DKIM support. Other DKIM relevant code is in


@@ -12,24 +12,45 @@
 
 #ifndef DISABLE_DKIM
 
 
 #ifndef DISABLE_DKIM
 

-#include "pdkim/pdkim.h"
+# include "pdkim/pdkim.h"
+
+# ifdef MACRO_PREDEF
+#  include "macro_predef.h"
+
+void
+params_dkim(void)
+{
+builtin_macro_create_var(US"_DKIM_SIGN_HEADERS", US PDKIM_DEFAULT_SIGN_HEADERS);
+}
+# else /*!MACRO_PREDEF*/
+
+
+
+pdkim_ctx dkim_sign_ctx;

 
 int dkim_verify_oldpool;
 pdkim_ctx *dkim_verify_ctx = NULL;
 
 int dkim_verify_oldpool;
 pdkim_ctx *dkim_verify_ctx = NULL;

-pdkim_signature *dkim_signatures = NULL;

 pdkim_signature *dkim_cur_sig = NULL;
 static const uschar * dkim_collect_error = NULL;
 
 pdkim_signature *dkim_cur_sig = NULL;
 static const uschar * dkim_collect_error = NULL;
 

-static int
-dkim_exim_query_dns_txt(char *name, char *answer)
+#define DKIM_MAX_SIGNATURES 20
+
+
+
+/*XXX the caller only uses the first record if we return multiple.
+*/
+
+uschar *
+dkim_exim_query_dns_txt(uschar * name)

 {
 dns_answer dnsa;
 dns_scan dnss;
 dns_record *rr;
 {
 dns_answer dnsa;
 dns_scan dnss;
 dns_record *rr;

+gstring * g = NULL;

 
 lookup_dnssec_authenticated = NULL;
 
 lookup_dnssec_authenticated = NULL;

-if (dns_lookup(&dnsa, US name, T_TXT, NULL) != DNS_SUCCEED)
-  return PDKIM_FAIL;   /*XXX better error detail?  logging? */
+if (dns_lookup(&dnsa, name, T_TXT, NULL) != DNS_SUCCEED)
+  return NULL; /*XXX better error detail?  logging? */

 
 /* Search for TXT record */
 
 
 /* Search for TXT record */
 


@@ -39,25 +60,33 @@ for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
   if (rr->type == T_TXT)
     {
     int rr_offset = 0;
   if (rr->type == T_TXT)
     {
     int rr_offset = 0;

-    int answer_offset = 0;

 
     /* Copy record content to the answer buffer */
 
     while (rr_offset < rr->size)
       {
       uschar len = rr->data[rr_offset++];
 
     /* Copy record content to the answer buffer */
 
     while (rr_offset < rr->size)
       {
       uschar len = rr->data[rr_offset++];

-      snprintf(answer + answer_offset,
-               PDKIM_DNS_TXT_MAX_RECLEN - answer_offset,
-               "%.*s", (int)len, CS  (rr->data + rr_offset));
+
+      g = string_catn(g, US(rr->data + rr_offset), len);
+      if (g->ptr >= PDKIM_DNS_TXT_MAX_RECLEN)
+       goto bad;
+

       rr_offset += len;
       rr_offset += len;

-      answer_offset += len;
-      if (answer_offset >= PDKIM_DNS_TXT_MAX_RECLEN)
-       return PDKIM_FAIL;      /*XXX better error detail?  logging? */

       }
       }

-    return PDKIM_OK;
+
+    /* check if this looks like a DKIM record */
+    if (Ustrncmp(g->s, "v=", 2) != 0 || strncasecmp(CS g->s, "v=dkim", 6) == 0)
+      {
+      gstring_reset_unused(g);
+      return string_from_gstring(g);
+      }
+
+    if (g) g->ptr = 0;         /* overwrite previous record */

     }
 
     }
 

-return PDKIM_FAIL;     /*XXX better error detail?  logging? */
+bad:
+if (g) store_reset(g);
+return NULL;   /*XXX better error detail?  logging? */

 }
 
 
 }
 
 


@@ -87,7 +116,7 @@ if (dkim_verify_ctx)
 /* Create new context */
 
 dkim_verify_ctx = pdkim_init_verify(&dkim_exim_query_dns_txt, dot_stuffing);
 /* Create new context */
 
 dkim_verify_ctx = pdkim_init_verify(&dkim_exim_query_dns_txt, dot_stuffing);

-dkim_collect_input = !!dkim_verify_ctx;
+dkim_collect_input = dkim_verify_ctx ? DKIM_MAX_SIGNATURES : 0;

 dkim_collect_error = NULL;
 
 /* Start feed up with any cached data */
 dkim_collect_error = NULL;
 
 /* Start feed up with any cached data */


@@ -109,197 +138,289 @@ if (  dkim_collect_input
   dkim_collect_error = pdkim_errstr(rc);
   log_write(0, LOG_MAIN,
             "DKIM: validation error: %.100s", dkim_collect_error);
   dkim_collect_error = pdkim_errstr(rc);
   log_write(0, LOG_MAIN,
             "DKIM: validation error: %.100s", dkim_collect_error);

-  dkim_collect_input = FALSE;
+  dkim_collect_input = 0;

   }
 store_pool = dkim_verify_oldpool;
 }
 
 
   }
 store_pool = dkim_verify_oldpool;
 }
 
 

-void
-dkim_exim_verify_finish(void)
+/* Log the result for the given signature */
+static void
+dkim_exim_verify_log_sig(pdkim_signature * sig)

 {
 {

-pdkim_signature * sig = NULL;
-int dkim_signers_size = 0, dkim_signers_ptr = 0, rc;
-const uschar * errstr;
-
-store_pool = POOL_PERM;
-
-/* Delete eventual previous signature chain */
-
-dkim_signers = NULL;
-dkim_signatures = NULL;
-
-if (dkim_collect_error)
-  {
-  log_write(0, LOG_MAIN,
-      "DKIM: Error during validation, disabling signature verification: %.100s",
-      dkim_collect_error);
-  dkim_disable_verify = TRUE;
-  goto out;
-  }
-
-dkim_collect_input = FALSE;
-
-/* Finish DKIM operation and fetch link to signatures chain */
-
-rc = pdkim_feed_finish(dkim_verify_ctx, &dkim_signatures, &errstr);
-if (rc != PDKIM_OK)
-  {
-  log_write(0, LOG_MAIN, "DKIM: validation error: %.100s%s%s", pdkim_errstr(rc),
-           errstr ? ": " : "", errstr ? errstr : US"");
-  goto out;
+gstring * logmsg;
+uschar * s;
+
+if (!sig) return;
+
+/* Remember the domain for the first pass result */
+
+if (  !dkim_verify_overall
+   && dkim_verify_status
+      ? Ustrcmp(dkim_verify_status, US"pass") == 0
+      : sig->verify_status == PDKIM_VERIFY_PASS
+   )
+  dkim_verify_overall = string_copy(sig->domain);
+
+/* Rewrite the sig result if the ACL overrode it.  This is only
+needed because the DMARC code (sigh) peeks at the dkim sigs.
+Mark the sig for this having been done. */
+
+if (  dkim_verify_status
+   && (  dkim_verify_status != dkim_exim_expand_query(DKIM_VERIFY_STATUS)
+      || dkim_verify_reason != dkim_exim_expand_query(DKIM_VERIFY_REASON)
+   )  )
+  {                    /* overridden by ACL */
+  sig->verify_ext_status = -1;
+  if (Ustrcmp(dkim_verify_status, US"fail") == 0)
+    sig->verify_status = PDKIM_VERIFY_POLICY | PDKIM_VERIFY_FAIL;
+  else if (Ustrcmp(dkim_verify_status, US"invalid") == 0)
+    sig->verify_status = PDKIM_VERIFY_POLICY | PDKIM_VERIFY_INVALID;
+  else if (Ustrcmp(dkim_verify_status, US"none") == 0)
+    sig->verify_status = PDKIM_VERIFY_POLICY | PDKIM_VERIFY_NONE;
+  else if (Ustrcmp(dkim_verify_status, US"pass") == 0)
+    sig->verify_status = PDKIM_VERIFY_POLICY | PDKIM_VERIFY_PASS;
+  else
+    sig->verify_status = -1;

   }
 
   }
 

-for (sig = dkim_signatures; sig; sig = sig->next)
-  {
-  int size = 0, ptr = 0;
-  uschar * logmsg = NULL, * s;
-
-  /* Log a line for each signature */
-
-  if (!(s = sig->domain)) s = US"<UNSET>";
-  logmsg = string_append(logmsg, &size, &ptr, 2, "d=", s);
-  if (!(s = sig->selector)) s = US"<UNSET>";
-  logmsg = string_append(logmsg, &size, &ptr, 2, " s=", s);
-  logmsg = string_append(logmsg, &size, &ptr, 7, 
-       " c=", sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
-       "/",   sig->canon_body    == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
-       " a=", sig->algo == PDKIM_ALGO_RSA_SHA256
-               ? "rsa-sha256"
-               : sig->algo == PDKIM_ALGO_RSA_SHA1 ? "rsa-sha1" : "err",
-       string_sprintf(" b=%d",
-                       (int)sig->sighash.len > -1 ? sig->sighash.len * 8 : 0));
-  if ((s= sig->identity)) logmsg = string_append(logmsg, &size, &ptr, 2, " i=", s);
-  if (sig->created > 0) logmsg = string_append(logmsg, &size, &ptr, 1,
-                                     string_sprintf(" t=%lu", sig->created));
-  if (sig->expires > 0) logmsg = string_append(logmsg, &size, &ptr, 1,
-                                     string_sprintf(" x=%lu", sig->expires));
-  if (sig->bodylength > -1) logmsg = string_append(logmsg, &size, &ptr, 1,
-                                     string_sprintf(" l=%lu", sig->bodylength));
-
+if (!LOGGING(dkim_verbose)) return;
+
+
+logmsg = string_catn(NULL, US"DKIM: ", 6);
+if (!(s = sig->domain)) s = US"<UNSET>";
+logmsg = string_append(logmsg, 2, "d=", s);
+if (!(s = sig->selector)) s = US"<UNSET>";
+logmsg = string_append(logmsg, 2, " s=", s);
+logmsg = string_append(logmsg, 7,
+  " c=", sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
+  "/",   sig->canon_body    == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
+  " a=", dkim_sig_to_a_tag(sig),
+string_sprintf(" b=" SIZE_T_FMT,
+               (int)sig->sighash.len > -1 ? sig->sighash.len * 8 : 0));
+if ((s= sig->identity)) logmsg = string_append(logmsg, 2, " i=", s);
+if (sig->created > 0) logmsg = string_cat(logmsg,
+                             string_sprintf(" t=%lu", sig->created));
+if (sig->expires > 0) logmsg = string_cat(logmsg,
+                             string_sprintf(" x=%lu", sig->expires));
+if (sig->bodylength > -1) logmsg = string_cat(logmsg,
+                             string_sprintf(" l=%lu", sig->bodylength));
+
+if (sig->verify_status & PDKIM_VERIFY_POLICY)
+  logmsg = string_append(logmsg, 5,
+           US" [", dkim_verify_status, US" - ", dkim_verify_reason, US"]");
+else

   switch (sig->verify_status)
     {
     case PDKIM_VERIFY_NONE:
   switch (sig->verify_status)
     {
     case PDKIM_VERIFY_NONE:

-      logmsg = string_append(logmsg, &size, &ptr, 1, " [not verified]");
+      logmsg = string_cat(logmsg, US" [not verified]");

       break;
 
     case PDKIM_VERIFY_INVALID:
       break;
 
     case PDKIM_VERIFY_INVALID:

-      logmsg = string_append(logmsg, &size, &ptr, 1, " [invalid - ");
+      logmsg = string_cat(logmsg, US" [invalid - ");

       switch (sig->verify_ext_status)
        {
        case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE:
       switch (sig->verify_ext_status)
        {
        case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE:

-         logmsg = string_append(logmsg, &size, &ptr, 1,
-                       "public key record (currently?) unavailable]");
+         logmsg = string_cat(logmsg,
+                       US"public key record (currently?) unavailable]");

          break;
 
        case PDKIM_VERIFY_INVALID_BUFFER_SIZE:
          break;
 
        case PDKIM_VERIFY_INVALID_BUFFER_SIZE:

-         logmsg = string_append(logmsg, &size, &ptr, 1,
-                       "overlong public key record]");
+         logmsg = string_cat(logmsg, US"overlong public key record]");

          break;
 
        case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD:
        case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT:
          break;
 
        case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD:
        case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT:

-         logmsg = string_append(logmsg, &size, &ptr, 1,
-                      "syntax error in public key record]");
+         logmsg = string_cat(logmsg, US"syntax error in public key record]");

          break;
 
          break;
 

-        case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR:
-          logmsg = string_append(logmsg, &size, &ptr, 1,
-                       "signature tag missing or invalid]");
-          break;
+       case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR:
+         logmsg = string_cat(logmsg, US"signature tag missing or invalid]");
+         break;

 
 

-        case PDKIM_VERIFY_INVALID_DKIM_VERSION:
-          logmsg = string_append(logmsg, &size, &ptr, 1,
-                       "unsupported DKIM version]");
-          break;
+       case PDKIM_VERIFY_INVALID_DKIM_VERSION:
+         logmsg = string_cat(logmsg, US"unsupported DKIM version]");
+         break;

 
        default:
 
        default:

-         logmsg = string_append(logmsg, &size, &ptr, 1,
-                       "unspecified problem]");
+         logmsg = string_cat(logmsg, US"unspecified problem]");

        }
       break;
 
     case PDKIM_VERIFY_FAIL:
        }
       break;
 
     case PDKIM_VERIFY_FAIL:

-      logmsg =
-       string_append(logmsg, &size, &ptr, 1, " [verification failed - ");
+      logmsg = string_cat(logmsg, US" [verification failed - ");

       switch (sig->verify_ext_status)
        {
        case PDKIM_VERIFY_FAIL_BODY:
       switch (sig->verify_ext_status)
        {
        case PDKIM_VERIFY_FAIL_BODY:

-         logmsg = string_append(logmsg, &size, &ptr, 1,
-                      "body hash mismatch (body probably modified in transit)]");
+         logmsg = string_cat(logmsg,
+              US"body hash mismatch (body probably modified in transit)]");

          break;
 
        case PDKIM_VERIFY_FAIL_MESSAGE:
          break;
 
        case PDKIM_VERIFY_FAIL_MESSAGE:

-         logmsg = string_append(logmsg, &size, &ptr, 1,
-                      "signature did not verify (headers probably modified in transit)]");
-       break;
+         logmsg = string_cat(logmsg,
+               US"signature did not verify "
+               "(headers probably modified in transit)]");
+         break;

 
        default:
 
        default:

-         logmsg = string_append(logmsg, &size, &ptr, 1, "unspecified reason]");
+         logmsg = string_cat(logmsg, US"unspecified reason]");

        }
       break;
 
     case PDKIM_VERIFY_PASS:
        }
       break;
 
     case PDKIM_VERIFY_PASS:

-      logmsg =
-       string_append(logmsg, &size, &ptr, 1, " [verification succeeded]");
+      logmsg = string_cat(logmsg, US" [verification succeeded]");

       break;
     }
 
       break;
     }
 

-  logmsg[ptr] = '\0';
-  log_write(0, LOG_MAIN, "DKIM: %s", logmsg);
+log_write(0, LOG_MAIN, "%s", string_from_gstring(logmsg));
+return;
+}

 
 

-  /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */

 
 

-  if (sig->domain)
-    dkim_signers = string_append_listele(dkim_signers, &dkim_signers_size,
-      &dkim_signers_ptr, ':', sig->domain);
+/* Log a line for each signature */
+void
+dkim_exim_verify_log_all(void)
+{
+pdkim_signature * sig;
+for (sig = dkim_signatures; sig; sig = sig->next) dkim_exim_verify_log_sig(sig);
+}

 
 

-  if (sig->identity)
-    dkim_signers = string_append_listele(dkim_signers, &dkim_signers_size,
-      &dkim_signers_ptr, ':', sig->identity);

 
 

-  /* Process next signature */
+void
+dkim_exim_verify_finish(void)
+{
+pdkim_signature * sig;
+int rc;
+gstring * g = NULL;
+const uschar * errstr = NULL;
+
+store_pool = POOL_PERM;
+
+/* Delete eventual previous signature chain */
+
+dkim_signers = NULL;
+dkim_signatures = NULL;
+
+if (dkim_collect_error)
+  {
+  log_write(0, LOG_MAIN,
+      "DKIM: Error during validation, disabling signature verification: %.100s",
+      dkim_collect_error);
+  dkim_disable_verify = TRUE;
+  goto out;

   }
 
   }
 

+dkim_collect_input = 0;
+
+/* Finish DKIM operation and fetch link to signatures chain */
+
+rc = pdkim_feed_finish(dkim_verify_ctx, (pdkim_signature **)&dkim_signatures,
+                       &errstr);
+if (rc != PDKIM_OK && errstr)
+  log_write(0, LOG_MAIN, "DKIM: validation error: %s", errstr);
+
+/* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */
+
+for (sig = dkim_signatures; sig; sig = sig->next)
+  {
+  if (sig->domain)   g = string_append_listele(g, ':', sig->domain);
+  if (sig->identity) g = string_append_listele(g, ':', sig->identity);
+  }
+
+if (g) dkim_signers = g->s;
+

 out:
 store_pool = dkim_verify_oldpool;
 }
 
 
 out:
 store_pool = dkim_verify_oldpool;
 }
 
 

-void
-dkim_exim_acl_setup(uschar * id)
+
+/* Args as per dkim_exim_acl_run() below */
+static int
+dkim_acl_call(uschar * id, gstring ** res_ptr,
+  uschar ** user_msgptr, uschar ** log_msgptr)
+{
+int rc;
+DEBUG(D_receive)
+  debug_printf("calling acl_smtp_dkim for dkim_cur_signer='%s'\n", id);
+
+rc = acl_check(ACL_WHERE_DKIM, NULL, acl_smtp_dkim, user_msgptr, log_msgptr);
+dkim_exim_verify_log_sig(dkim_cur_sig);
+*res_ptr = string_append_listele(*res_ptr, ':', dkim_verify_status);
+return rc;
+}
+
+
+
+/* For the given identity, run the DKIM ACL once for each matching signature.
+
+Arguments
+ id            Identity to look for in dkim signatures
+ res_ptr       ptr to growable string-list of status results,
+               appended to per ACL run
+ user_msgptr   where to put a user error (for SMTP response)
+ log_msgptr    where to put a logging message (not for SMTP response)
+
+Returns:       OK         access is granted by an ACCEPT verb
+               DISCARD    access is granted by a DISCARD verb
+               FAIL       access is denied
+               FAIL_DROP  access is denied; drop the connection
+               DEFER      can't tell at the moment
+               ERROR      disaster
+*/
+
+int
+dkim_exim_acl_run(uschar * id, gstring ** res_ptr,
+  uschar ** user_msgptr, uschar ** log_msgptr)

 {
 pdkim_signature * sig;
 uschar * cmp_val;
 {
 pdkim_signature * sig;
 uschar * cmp_val;

+int rc = -1;

 
 

-dkim_cur_sig = NULL;
+dkim_verify_status = US"none";
+dkim_verify_reason = US"";

 dkim_cur_signer = id;
 
 if (dkim_disable_verify || !id || !dkim_verify_ctx)
 dkim_cur_signer = id;
 
 if (dkim_disable_verify || !id || !dkim_verify_ctx)

-  return;
+  return OK;

 
 

-/* Find signature to run ACL on */
+/* Find signatures to run ACL on */

 
 for (sig = dkim_signatures; sig; sig = sig->next)
   if (  (cmp_val = Ustrchr(id, '@') != NULL ? US sig->identity : US sig->domain)
      && strcmpic(cmp_val, id) == 0
      )
     {
 
 for (sig = dkim_signatures; sig; sig = sig->next)
   if (  (cmp_val = Ustrchr(id, '@') != NULL ? US sig->identity : US sig->domain)
      && strcmpic(cmp_val, id) == 0
      )
     {

-    dkim_cur_sig = sig;
-

     /* The "dkim_domain" and "dkim_selector" expansion variables have
     /* The "dkim_domain" and "dkim_selector" expansion variables have

-       related globals, since they are used in the signing code too.
-       Instead of inventing separate names for verification, we set
-       them here. This is easy since a domain and selector is guaranteed
-       to be in a signature. The other dkim_* expansion items are
-       dynamically fetched from dkim_cur_sig at expansion time (see
-       function below). */
+    related globals, since they are used in the signing code too.
+    Instead of inventing separate names for verification, we set
+    them here. This is easy since a domain and selector is guaranteed
+    to be in a signature. The other dkim_* expansion items are
+    dynamically fetched from dkim_cur_sig at expansion time (see
+    dkim_exim_expand_query() below). */

 
 

+    dkim_cur_sig = sig;

     dkim_signing_domain = US sig->domain;
     dkim_signing_selector = US sig->selector;
     dkim_key_length = sig->sighash.len * 8;
     dkim_signing_domain = US sig->domain;
     dkim_signing_selector = US sig->selector;
     dkim_key_length = sig->sighash.len * 8;

-    return;
+
+    /* These two return static strings, so we can compare the addr
+    later to see if the ACL overwrote them.  Check that when logging */
+
+    dkim_verify_status = dkim_exim_expand_query(DKIM_VERIFY_STATUS);
+    dkim_verify_reason = dkim_exim_expand_query(DKIM_VERIFY_REASON);
+
+    if ((rc = dkim_acl_call(id, res_ptr, user_msgptr, log_msgptr)) != OK)
+      return rc;

     }
     }

+
+if (rc != -1)
+  return rc;
+
+/* No matching sig found.  Call ACL once anyway. */
+
+dkim_cur_sig = NULL;
+return dkim_acl_call(id, res_ptr, user_msgptr, log_msgptr);

 }
 
 
 }
 
 


@@ -338,16 +459,11 @@ if (!dkim_verify_ctx || dkim_disable_verify || !dkim_cur_sig)
 switch (what)
   {
   case DKIM_ALGO:
 switch (what)
   {
   case DKIM_ALGO:

-    switch (dkim_cur_sig->algo)
-      {
-      case PDKIM_ALGO_RSA_SHA1:        return US"rsa-sha1";
-      case PDKIM_ALGO_RSA_SHA256:
-      default:                 return US"rsa-sha256";
-      }
+    return dkim_sig_to_a_tag(dkim_cur_sig);

 
   case DKIM_BODYLENGTH:
     return dkim_cur_sig->bodylength >= 0
 
   case DKIM_BODYLENGTH:
     return dkim_cur_sig->bodylength >= 0

-      ? string_sprintf(OFF_T_FMT, (LONGLONG_T) dkim_cur_sig->bodylength)
+      ? string_sprintf("%ld", dkim_cur_sig->bodylength)

       : dkim_exim_expand_defaults(what);
 
   case DKIM_CANON_BODY:
       : dkim_exim_expand_defaults(what);
 
   case DKIM_CANON_BODY:


@@ -359,12 +475,12 @@ switch (what)
       }
 
   case DKIM_CANON_HEADERS:
       }
 
   case DKIM_CANON_HEADERS:

-  switch (dkim_cur_sig->canon_headers)
-    {
-    case PDKIM_CANON_RELAXED:  return US"relaxed";
-    case PDKIM_CANON_SIMPLE:
-    default:                   return US"simple";
-    }
+    switch (dkim_cur_sig->canon_headers)
+      {
+      case PDKIM_CANON_RELAXED:        return US"relaxed";
+      case PDKIM_CANON_SIMPLE:
+      default:                 return US"simple";
+      }

 
   case DKIM_COPIEDHEADERS:
     return dkim_cur_sig->copiedheaders
 
   case DKIM_COPIEDHEADERS:
     return dkim_cur_sig->copiedheaders


@@ -372,12 +488,12 @@ switch (what)
 
   case DKIM_CREATED:
     return dkim_cur_sig->created > 0
 
   case DKIM_CREATED:
     return dkim_cur_sig->created > 0

-      ? string_sprintf("%llu", dkim_cur_sig->created)
+      ? string_sprintf("%lu", dkim_cur_sig->created)

       : dkim_exim_expand_defaults(what);
 
   case DKIM_EXPIRES:
     return dkim_cur_sig->expires > 0
       : dkim_exim_expand_defaults(what);
 
   case DKIM_EXPIRES:
     return dkim_cur_sig->expires > 0

-      ? string_sprintf("%llu", dkim_cur_sig->expires)
+      ? string_sprintf("%lu", dkim_cur_sig->expires)

       : dkim_exim_expand_defaults(what);
 
   case DKIM_HEADERNAMES:
       : dkim_exim_expand_defaults(what);
 
   case DKIM_HEADERNAMES:


@@ -450,193 +566,182 @@ switch (what)
 }
 
 
 }
 
 

-/* Generate signatures for the given file, returning a string.
+void
+dkim_exim_sign_init(void)
+{
+int old_pool = store_pool;
+store_pool = POOL_MAIN;
+pdkim_init_context(&dkim_sign_ctx, FALSE, &dkim_exim_query_dns_txt);
+store_pool = old_pool;
+}
+
+
+/* Generate signatures for the given file.

 If a prefix is given, prepend it to the file for the calculations.
 If a prefix is given, prepend it to the file for the calculations.

+
+Return:
+  NULL:                error; error string written
+  string:      signature header(s), or a zero-length string (not an error)

 */
 
 */
 

-uschar *
+gstring *

 dkim_exim_sign(int fd, off_t off, uschar * prefix,
   struct ob_dkim * dkim, const uschar ** errstr)
 {
 dkim_exim_sign(int fd, off_t off, uschar * prefix,
   struct ob_dkim * dkim, const uschar ** errstr)
 {

-const uschar * dkim_domain;
+const uschar * dkim_domain = NULL;

 int sep = 0;
 int sep = 0;

-uschar *seen_items = NULL;
-int seen_items_size = 0;
-int seen_items_offset = 0;
-uschar *dkim_canon_expanded;
-uschar *dkim_sign_headers_expanded;
-uschar *dkim_private_key_expanded;
-pdkim_ctx *ctx = NULL;
-uschar *rc = NULL;
-uschar *sigbuf = NULL;
-int sigsize = 0;
-int sigptr = 0;
-pdkim_signature *signature;
-int pdkim_canon;
+gstring * seen_doms = NULL;
+pdkim_signature * sig;
+gstring * sigbuf;

 int pdkim_rc;
 int sread;
 uschar buf[4096];
 int save_errno = 0;
 int old_pool = store_pool;
 int pdkim_rc;
 int sread;
 uschar buf[4096];
 int save_errno = 0;
 int old_pool = store_pool;

+uschar * errwhen;
+const uschar * s;
+
+if (dkim->dot_stuffed)
+  dkim_sign_ctx.flags |= PDKIM_DOT_TERM;

 
 store_pool = POOL_MAIN;
 
 
 store_pool = POOL_MAIN;
 

-if (!(dkim_domain = expand_cstring(dkim->dkim_domain)))
-  {
+if ((s = dkim->dkim_domain) && !(dkim_domain = expand_cstring(s)))

   /* expansion error, do not send message. */
   /* expansion error, do not send message. */

-  log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
-            "dkim_domain: %s", expand_string_message);
-  goto bad;
-  }
+  { errwhen = US"dkim_domain"; goto expand_bad; }

 
 /* Set $dkim_domain expansion variable to each unique domain in list. */
 
 
 /* Set $dkim_domain expansion variable to each unique domain in list. */
 

-while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0)))
+if (dkim_domain)
+  while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0)))

   {
   {

+  const uschar * dkim_sel;
+  int sel_sep = 0;
+

   if (dkim_signing_domain[0] == '\0')
     continue;
 
   /* Only sign once for each domain, no matter how often it
   appears in the expanded list. */
 
   if (dkim_signing_domain[0] == '\0')
     continue;
 
   /* Only sign once for each domain, no matter how often it
   appears in the expanded list. */
 

-  if (seen_items)
-    {
-    const uschar *seen_items_list = seen_items;
-    if (match_isinlist(dkim_signing_domain,
-                       &seen_items_list, 0, NULL, NULL, MCL_STRING, TRUE,
-                       NULL) == OK)
-      continue;
-
-    seen_items =
-      string_append(seen_items, &seen_items_size, &seen_items_offset, 1, ":");
-    }
-
-  seen_items =
-    string_append(seen_items, &seen_items_size, &seen_items_offset, 1,
-                dkim_signing_domain);
-  seen_items[seen_items_offset] = '\0';
-
-  /* Set up $dkim_selector expansion variable. */
+  if (match_isinlist(dkim_signing_domain, CUSS &seen_doms,
+      0, NULL, NULL, MCL_STRING, TRUE, NULL) == OK)
+    continue;

 
 

-  if (!(dkim_signing_selector = expand_string(dkim->dkim_selector)))
-    {
-    log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
-              "dkim_selector: %s", expand_string_message);
-    goto bad;
-    }
+  seen_doms = string_append_listele(seen_doms, ':', dkim_signing_domain);

 
 

-  /* Get canonicalization to use */
+  /* Set $dkim_selector expansion variable to each selector in list,
+  for this domain. */

 
 

-  dkim_canon_expanded = dkim->dkim_canon
-    ? expand_string(dkim->dkim_canon) : US"relaxed";
-  if (!dkim_canon_expanded)
-    {
-    /* expansion error, do not send message. */
-    log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
-              "dkim_canon: %s", expand_string_message);
-    goto bad;
-    }
+  if (!(dkim_sel = expand_string(dkim->dkim_selector)))
+    { errwhen = US"dkim_selector"; goto expand_bad; }

 
 

-  if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0)
-    pdkim_canon = PDKIM_CANON_RELAXED;
-  else if (Ustrcmp(dkim_canon_expanded, "simple") == 0)
-    pdkim_canon = PDKIM_CANON_SIMPLE;
-  else
+  while ((dkim_signing_selector = string_nextinlist(&dkim_sel, &sel_sep,
+         NULL, 0)))

     {
     {

-    log_write(0, LOG_MAIN,
-              "DKIM: unknown canonicalization method '%s', defaulting to 'relaxed'.\n",
-              dkim_canon_expanded);
-    pdkim_canon = PDKIM_CANON_RELAXED;
-    }
-
-  dkim_sign_headers_expanded = NULL;
-  if (dkim->dkim_sign_headers)
-    if (!(dkim_sign_headers_expanded = expand_string(dkim->dkim_sign_headers)))
+    uschar * dkim_canon_expanded;
+    int pdkim_canon;
+    uschar * dkim_sign_headers_expanded = NULL;
+    uschar * dkim_private_key_expanded;
+    uschar * dkim_hash_expanded;
+    uschar * dkim_identity_expanded = NULL;
+
+    /* Get canonicalization to use */
+
+    dkim_canon_expanded = dkim->dkim_canon
+      ? expand_string(dkim->dkim_canon) : US"relaxed";
+    if (!dkim_canon_expanded)  /* expansion error, do not send message. */
+      { errwhen = US"dkim_canon"; goto expand_bad; }
+
+    if (Ustrcmp(dkim_canon_expanded, "relaxed") == 0)
+      pdkim_canon = PDKIM_CANON_RELAXED;
+    else if (Ustrcmp(dkim_canon_expanded, "simple") == 0)
+      pdkim_canon = PDKIM_CANON_SIMPLE;
+    else

       {
       {

-      log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
-                "dkim_sign_headers: %s", expand_string_message);
-      goto bad;
+      log_write(0, LOG_MAIN,
+                "DKIM: unknown canonicalization method '%s', defaulting to 'relaxed'.\n",
+                dkim_canon_expanded);
+      pdkim_canon = PDKIM_CANON_RELAXED;

       }
       }

-                       /* else pass NULL, which means default header list */

 
 

-  /* Get private key to use. */
+    if (  dkim->dkim_sign_headers
+       && !(dkim_sign_headers_expanded = expand_string(dkim->dkim_sign_headers)))
+      { errwhen = US"dkim_sign_header"; goto expand_bad; }
+    /* else pass NULL, which means default header list */

 
 

-  if (!(dkim_private_key_expanded = expand_string(dkim->dkim_private_key)))
-    {
-    log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand "
-              "dkim_private_key: %s", expand_string_message);
-    goto bad;
-    }
+    /* Get private key to use. */

 
 

-  if (  Ustrlen(dkim_private_key_expanded) == 0
-     || Ustrcmp(dkim_private_key_expanded, "0") == 0
-     || Ustrcmp(dkim_private_key_expanded, "false") == 0
-     )
-    continue;          /* don't sign, but no error */
+    if (!(dkim_private_key_expanded = expand_string(dkim->dkim_private_key)))
+      { errwhen = US"dkim_private_key"; goto expand_bad; }

 
 

-  if (dkim_private_key_expanded[0] == '/')
-    {
-    int privkey_fd, off = 0, len;
+    if (  Ustrlen(dkim_private_key_expanded) == 0
+       || Ustrcmp(dkim_private_key_expanded, "0") == 0
+       || Ustrcmp(dkim_private_key_expanded, "false") == 0
+       )
+      continue;                /* don't sign, but no error */
+
+    if (  dkim_private_key_expanded[0] == '/'
+       && !(dkim_private_key_expanded =
+            expand_file_big_buffer(dkim_private_key_expanded)))
+      goto bad;

 
 

-    /* Looks like a filename, load the private key. */
+    if (!(dkim_hash_expanded = expand_string(dkim->dkim_hash)))
+      { errwhen = US"dkim_hash"; goto expand_bad; }
+
+    if (dkim->dkim_identity)
+      if (!(dkim_identity_expanded = expand_string(dkim->dkim_identity)))
+       { errwhen = US"dkim_identity"; goto expand_bad; }
+      else if (!*dkim_identity_expanded)
+       dkim_identity_expanded = NULL;
+
+    if (!(sig = pdkim_init_sign(&dkim_sign_ctx, dkim_signing_domain,
+                         dkim_signing_selector,
+                         dkim_private_key_expanded,
+                         dkim_hash_expanded,
+                         errstr
+                         )))
+      goto bad;
+    dkim_private_key_expanded[0] = '\0';

 
 

-    memset(big_buffer, 0, big_buffer_size);
+    pdkim_set_optional(sig,
+                       CS dkim_sign_headers_expanded,
+                       CS dkim_identity_expanded,
+                       pdkim_canon,
+                       pdkim_canon, -1, 0, 0);

 
 

-    if ((privkey_fd = open(CS dkim_private_key_expanded, O_RDONLY)) < 0)
-      {
-      log_write(0, LOG_MAIN | LOG_PANIC, "unable to open "
-                "private key file for reading: %s",
-                dkim_private_key_expanded);
+    if (!pdkim_set_sig_bodyhash(&dkim_sign_ctx, sig))

       goto bad;
       goto bad;

-      }

 
 

-    do
+    if (!dkim_sign_ctx.sig)            /* link sig to context chain */
+      dkim_sign_ctx.sig = sig;
+    else

       {
       {

-      if ((len = read(privkey_fd, big_buffer + off, big_buffer_size - 2 - off)) < 0)
-       {
-       (void) close(privkey_fd);
-       log_write(0, LOG_MAIN|LOG_PANIC, "unable to read private key file: %s",
-                  dkim_private_key_expanded);
-       goto bad;
-       }
-      off += len;
+      pdkim_signature * n = dkim_sign_ctx.sig;
+      while (n->next) n = n->next;
+      n->next = sig;

       }
       }

-    while (len > 0);
-
-    (void) close(privkey_fd);
-    big_buffer[off] = '\0';
-    dkim_private_key_expanded = big_buffer;

     }
     }

+  }

 
 

-/*XXX so we currently nail signing to RSA + SHA256.  Need to extract algo
-from privkey, and provide means for selecting hash-method.
-Check for disallowed combos.
-Will need new dkim_ transport option for hash. */
-
-  if (!(ctx = pdkim_init_sign(CS dkim_signing_domain,
-                       CS dkim_signing_selector,
-                       CS dkim_private_key_expanded,
-                       PDKIM_ALGO_RSA_SHA256,
-                       dkim->dot_stuffed,
-                       &dkim_exim_query_dns_txt,
-                       errstr
-                       )))
-    goto bad;
-  dkim_private_key_expanded[0] = '\0';
-  pdkim_set_optional(ctx,
-                     CS dkim_sign_headers_expanded,
-                     NULL,
-                     pdkim_canon,
-                     pdkim_canon, -1, 0, 0);
+/* We may need to carry on with the data-feed even if there are no DKIM sigs to
+produce, if some other package (eg. ARC) is signing. */

 
 

-  if (prefix)
-    pdkim_feed(ctx, prefix, Ustrlen(prefix));
+if (!dkim_sign_ctx.sig && !dkim->force_bodyhash)
+  {
+  DEBUG(D_transport) debug_printf("DKIM: no viable signatures to use\n");
+  sigbuf = string_get(1);      /* return a zero-len string */
+  }
+else
+  {
+  if (prefix && (pdkim_rc = pdkim_feed(&dkim_sign_ctx, prefix, Ustrlen(prefix))) != PDKIM_OK)
+    goto pk_bad;

 
   if (lseek(fd, off, SEEK_SET) < 0)
     sread = -1;
   else
     while ((sread = read(fd, &buf, sizeof(buf))) > 0)
 
   if (lseek(fd, off, SEEK_SET) < 0)
     sread = -1;
   else
     while ((sread = read(fd, &buf, sizeof(buf))) > 0)

-      if ((pdkim_rc = pdkim_feed(ctx, buf, sread)) != PDKIM_OK)
+      if ((pdkim_rc = pdkim_feed(&dkim_sign_ctx, buf, sread)) != PDKIM_OK)

        goto pk_bad;
 
   /* Handle failed read above. */
        goto pk_bad;
 
   /* Handle failed read above. */


@@ -647,37 +752,114 @@ Will need new dkim_ transport option for hash. */
     goto bad;
     }
 
     goto bad;
     }
 

-  if ((pdkim_rc = pdkim_feed_finish(ctx, &signature, errstr)) != PDKIM_OK)
-    goto pk_bad;
+  /* Build string of headers, one per signature */

 
 

-  sigbuf = string_append(sigbuf, &sigsize, &sigptr, 2,
-                         US signature->signature_header, US"\r\n");
+  if ((pdkim_rc = pdkim_feed_finish(&dkim_sign_ctx, &sig, errstr)) != PDKIM_OK)
+    goto pk_bad;

 
 

-  pdkim_free_ctx(ctx);
-  ctx = NULL;
+  if (!sig)
+    {
+    DEBUG(D_transport) debug_printf("DKIM: no signatures to use\n");
+    sigbuf = string_get(1);    /* return a zero-len string */
+    }
+  else for (sigbuf = NULL; sig; sig = sig->next)
+    sigbuf = string_append(sigbuf, 2, US sig->signature_header, US"\r\n");

   }
 
   }
 

-if (sigbuf)
-  {
-  sigbuf[sigptr] = '\0';
-  rc = sigbuf;
-  }
-else
-  rc = US"";
-

 CLEANUP:
 CLEANUP:

-  if (ctx)
-    pdkim_free_ctx(ctx);
+  (void) string_from_gstring(sigbuf);

   store_pool = old_pool;
   errno = save_errno;
   store_pool = old_pool;
   errno = save_errno;

-  return rc;
+  return sigbuf;

 
 pk_bad:
   log_write(0, LOG_MAIN|LOG_PANIC,
                "DKIM: signing failed: %.100s", pdkim_errstr(pdkim_rc));
 bad:
 
 pk_bad:
   log_write(0, LOG_MAIN|LOG_PANIC,
                "DKIM: signing failed: %.100s", pdkim_errstr(pdkim_rc));
 bad:

-  rc = NULL;
+  sigbuf = NULL;

   goto CLEANUP;
   goto CLEANUP;

+
+expand_bad:
+  log_write(0, LOG_MAIN | LOG_PANIC, "failed to expand %s: %s",
+             errwhen, expand_string_message);
+  goto bad;

 }
 
 }
 

-#endif
+
+
+
+gstring *
+authres_dkim(gstring * g)
+{
+pdkim_signature * sig;
+int start = 0;         /* compiler quietening */
+
+DEBUG(D_acl) start = g->ptr;
+
+for (sig = dkim_signatures; sig; sig = sig->next)
+  {
+  g = string_catn(g, US";\n\tdkim=", 8);
+
+  if (sig->verify_status & PDKIM_VERIFY_POLICY)
+    g = string_append(g, 5,
+      US"policy (", dkim_verify_status, US" - ", dkim_verify_reason, US")");
+  else switch(sig->verify_status)
+    {
+    case PDKIM_VERIFY_NONE:    g = string_cat(g, US"none"); break;
+    case PDKIM_VERIFY_INVALID:
+      switch (sig->verify_ext_status)
+       {
+       case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE:
+          g = string_cat(g, US"tmperror (pubkey unavailable)\n\t\t"); break;
+        case PDKIM_VERIFY_INVALID_BUFFER_SIZE:
+          g = string_cat(g, US"permerror (overlong public key record)\n\t\t"); break;
+        case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD:
+        case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT:
+          g = string_cat(g, US"neutral (public key record import problem)\n\t\t");
+          break;
+        case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR:
+          g = string_cat(g, US"neutral (signature tag missing or invalid)\n\t\t");
+          break;
+        case PDKIM_VERIFY_INVALID_DKIM_VERSION:
+          g = string_cat(g, US"neutral (unsupported DKIM version)\n\t\t");
+          break;
+        default:
+          g = string_cat(g, US"permerror (unspecified problem)\n\t\t"); break;
+       }
+      break;
+    case PDKIM_VERIFY_FAIL:
+      switch (sig->verify_ext_status)
+       {
+       case PDKIM_VERIFY_FAIL_BODY:
+          g = string_cat(g,
+           US"fail (body hash mismatch; body probably modified in transit)\n\t\t");
+         break;
+        case PDKIM_VERIFY_FAIL_MESSAGE:
+          g = string_cat(g,
+           US"fail (signature did not verify; headers probably modified in transit)\n\t\t");
+         break;
+        default:
+          g = string_cat(g, US"fail (unspecified reason)\n\t\t");
+         break;
+       }
+      break;
+    case PDKIM_VERIFY_PASS:    g = string_cat(g, US"pass"); break;
+    default:                   g = string_cat(g, US"permerror"); break;
+    }
+  if (sig->domain)   g = string_append(g, 2, US" header.d=", sig->domain);
+  if (sig->identity) g = string_append(g, 2, US" header.i=", sig->identity);
+  if (sig->selector) g = string_append(g, 2, US" header.s=", sig->selector);
+  g = string_append(g, 2, US" header.a=", dkim_sig_to_a_tag(sig));
+  }
+
+DEBUG(D_acl)
+  if (g->ptr == start)
+    debug_printf("DKIM: no authres\n");
+  else
+    debug_printf("DKIM: authres '%.*s'\n", g->ptr - start - 3, g->s + start + 3);
+return g;
+}
+
+
+# endif        /*!MACRO_PREDEF*/
+#endif /*!DISABLE_DKIM*/