DKIM: Ed25519 signatures (GnuTLS 3.6.0 and later)

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

diff --git a/src/src/dkim.c b/src/src/dkim.c
index 852ae17f3c5398642139b6f0c7372e2968798013..c7bf641527822a7fecc97fe383ca7c548a5ea2f1 100644 (file)
--- a/src/src/dkim.c
+++ b/src/src/dkim.c
@@ -36,19 +36,19 @@ static const uschar * dkim_collect_error = NULL;
 
 
 /*XXX the caller only uses the first record if we return multiple.
-Could we hand back an allocated string?
 */
 
-static int
-dkim_exim_query_dns_txt(char *name, char *answer)
+static uschar *
+dkim_exim_query_dns_txt(char * name)
 {
 dns_answer dnsa;
 dns_scan dnss;
 dns_record *rr;
+gstring * g = NULL;
 
 lookup_dnssec_authenticated = NULL;
 if (dns_lookup(&dnsa, US name, T_TXT, NULL) != DNS_SUCCEED)
-  return PDKIM_FAIL;   /*XXX better error detail?  logging? */
+  return NULL; /*XXX better error detail?  logging? */
 
 /* Search for TXT record */
 
@@ -58,29 +58,33 @@ for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
   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++];
-      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;
-      answer_offset += len;
-      if (answer_offset >= PDKIM_DNS_TXT_MAX_RECLEN)
-       return PDKIM_FAIL;      /*XXX better error detail?  logging? */
       }
 
     /* check if this looks like a DKIM record */
-    if (strncmp(answer, "v=", 2) == 0 && strncasecmp(answer, "v=dkim", 6) != 0)
-      continue;
-    return PDKIM_OK;
+    if (Ustrncmp(g->s, "v=", 2) != 0 || strncasecmp(CS g->s, "v=dkim", 6) == 0)
+      {
+      store_reset(g->s + g->ptr + 1);
+      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? */
 }
 
 
@@ -264,7 +268,7 @@ dkim_exim_verify_finish(void)
 pdkim_signature * sig;
 int rc;
 gstring * g = NULL;
-const uschar * errstr;
+const uschar * errstr = NULL;
 
 store_pool = POOL_PERM;
 
@@ -287,12 +291,8 @@ 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;
-  }
+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 */
 
@@ -706,6 +706,9 @@ while ((dkim_signing_domain = string_nextinlist(&dkim_domain, &sep, NULL, 0)))
                        pdkim_canon,
                        pdkim_canon, -1, 0, 0);
 
+    if (!pdkim_set_bodyhash(&ctx, sig))
+      goto bad;
+
     if (!ctx.sig)              /* link sig to context chain */
       ctx.sig = sig;
     else
@@ -723,7 +726,7 @@ if (!ctx.sig)
   goto CLEANUP;
   }
 
-if (prefix && (pdkim_feed(&ctx, prefix, Ustrlen(prefix))) != PDKIM_OK)
+if (prefix && (pdkim_rc = pdkim_feed(&ctx, prefix, Ustrlen(prefix))) != PDKIM_OK)
   goto pk_bad;
 
 if (lseek(fd, off, SEEK_SET) < 0)