Track tainted data and refuse to expand it

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

diff --git a/src/src/dkim.c b/src/src/dkim.c
index edbeded5e4ac886885d37847e9f9b12219f2d568..a410ed55bbcbfe2734b12493c784bc0c67429f8f 100644 (file)
--- a/src/src/dkim.c
+++ b/src/src/dkim.c
@@ -43,9 +43,12 @@ static const uschar * dkim_collect_error = NULL;
 uschar *
 dkim_exim_query_dns_txt(uschar * name)
 {
+/*XXX need to always alloc the dnsa, from tainted mem.
+Then, we hope, the answers will be tainted */
+
 dns_answer dnsa;
 dns_scan dnss;
-dns_record *rr;
+rmark reset_point = store_mark();
 gstring * g = NULL;
 
 lookup_dnssec_authenticated = NULL;
@@ -54,7 +57,7 @@ if (dns_lookup(&dnsa, name, T_TXT, NULL) != DNS_SUCCEED)
 
 /* Search for TXT record */
 
-for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
+for (dns_record * rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
      rr;
      rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
   if (rr->type == T_TXT)
@@ -77,7 +80,7 @@ for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
     /* 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);
+      gstring_release_unused(g);
       return string_from_gstring(g);
       }
 
@@ -85,7 +88,7 @@ for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
     }
 
 bad:
-if (g) store_reset(g);
+store_reset(reset_point);
 return NULL;   /*XXX better error detail?  logging? */
 }
 
@@ -192,19 +195,18 @@ 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));
+logmsg = string_fmt_append(logmsg, " c=%s/%s a=%s b=" SIZE_T_FMT,
+         sig->canon_headers == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
+         sig->canon_body    == PDKIM_CANON_SIMPLE ? "simple" : "relaxed",
+         dkim_sig_to_a_tag(sig),
+         (int)sig->sighash.len > -1 ? sig->sighash.len * 8 : (size_t)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->created > 0) logmsg = string_fmt_append(logmsg, " t=%lu",
+                                   sig->created);
+if (sig->expires > 0) logmsg = string_fmt_append(logmsg, " x=%lu",
+                                   sig->expires);
+if (sig->bodylength > -1) logmsg = string_fmt_append(logmsg, " l=%lu",
+                                   sig->bodylength);
 
 if (sig->verify_status & PDKIM_VERIFY_POLICY)
   logmsg = string_append(logmsg, 5,
@@ -281,15 +283,14 @@ return;
 void
 dkim_exim_verify_log_all(void)
 {
-pdkim_signature * sig;
-for (sig = dkim_signatures; sig; sig = sig->next) dkim_exim_verify_log_sig(sig);
+for (pdkim_signature * sig = dkim_signatures; sig; sig = sig->next)
+  dkim_exim_verify_log_sig(sig);
 }
 
 
 void
 dkim_exim_verify_finish(void)
 {
-pdkim_signature * sig;
 int rc;
 gstring * g = NULL;
 const uschar * errstr = NULL;
@@ -306,7 +307,7 @@ if (dkim_collect_error)
   log_write(0, LOG_MAIN,
       "DKIM: Error during validation, disabling signature verification: %.100s",
       dkim_collect_error);
-  dkim_disable_verify = TRUE;
+  f.dkim_disable_verify = TRUE;
   goto out;
   }
 
@@ -321,7 +322,7 @@ if (rc != PDKIM_OK && errstr)
 
 /* Build a colon-separated list of signing domains (and identities, if present) in dkim_signers */
 
-for (sig = dkim_signatures; sig; sig = sig->next)
+for (pdkim_signature * 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);
@@ -373,7 +374,6 @@ int
 dkim_exim_acl_run(uschar * id, gstring ** res_ptr,
   uschar ** user_msgptr, uschar ** log_msgptr)
 {
-pdkim_signature * sig;
 uschar * cmp_val;
 int rc = -1;
 
@@ -381,12 +381,12 @@ dkim_verify_status = US"none";
 dkim_verify_reason = US"";
 dkim_cur_signer = id;
 
-if (dkim_disable_verify || !id || !dkim_verify_ctx)
+if (f.dkim_disable_verify || !id || !dkim_verify_ctx)
   return OK;
 
 /* Find signatures to run ACL on */
 
-for (sig = dkim_signatures; sig; sig = sig->next)
+for (pdkim_signature * sig = dkim_signatures; sig; sig = sig->next)
   if (  (cmp_val = Ustrchr(id, '@') != NULL ? US sig->identity : US sig->domain)
      && strcmpic(cmp_val, id) == 0
      )
@@ -453,7 +453,7 @@ switch (what)
 uschar *
 dkim_exim_expand_query(int what)
 {
-if (!dkim_verify_ctx || dkim_disable_verify || !dkim_cur_sig)
+if (!dkim_verify_ctx || f.dkim_disable_verify || !dkim_cur_sig)
   return dkim_exim_expand_defaults(what);
 
 switch (what)
@@ -624,6 +624,7 @@ if (dkim_domain)
   /* Only sign once for each domain, no matter how often it
   appears in the expanded list. */
 
+  dkim_signing_domain = string_copylc(dkim_signing_domain);
   if (match_isinlist(dkim_signing_domain, CUSS &seen_doms,
       0, NULL, NULL, MCL_STRING, TRUE, NULL) == OK)
     continue;
@@ -702,7 +703,7 @@ if (dkim_domain)
        { errwhen = US"dkim_timestamps"; goto expand_bad; }
       else
        xval = (tval = (unsigned long) time(NULL))
-             + strtoul(dkim_timestamps_expanded, NULL, 10);
+             + strtoul(CCS dkim_timestamps_expanded, NULL, 10);
 
     if (!(sig = pdkim_init_sign(&dkim_sign_ctx, dkim_signing_domain,
                          dkim_signing_selector,
@@ -800,12 +801,11 @@ expand_bad:
 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)
+for (pdkim_signature * sig = dkim_signatures; sig; sig = sig->next)
   {
   g = string_catn(g, US";\n\tdkim=", 8);