+/*************************************************
+* Check for blind recipients *
+*************************************************/
+
+/* This function checks that every (envelope) recipient is mentioned in either
+the To: or Cc: header lines, thus detecting blind carbon copies.
+
+There are two ways of scanning that could be used: either scan the header lines
+and tick off the recipients, or scan the recipients and check the header lines.
+The original proposed patch did the former, but I have chosen to do the latter,
+because (a) it requires no memory and (b) will use fewer resources when there
+are many addresses in To: and/or Cc: and only one or two envelope recipients.
+
+Arguments: none
+Returns: OK if there are no blind recipients
+ FAIL if there is at least one blind recipient
+*/
+
+int
+verify_check_notblind(void)
+{
+int i;
+for (i = 0; i < recipients_count; i++)
+ {
+ header_line *h;
+ BOOL found = FALSE;
+ uschar *address = recipients_list[i].address;
+
+ for (h = header_list; !found && h != NULL; h = h->next)
+ {
+ uschar *colon, *s;
+
+ if (h->type != htype_to && h->type != htype_cc) continue;
+
+ colon = Ustrchr(h->text, ':');
+ s = colon + 1;
+ while (isspace(*s)) s++;
+
+ parse_allow_group = TRUE; /* Allow group syntax */
+
+ /* Loop for multiple addresses in the header */
+
+ while (*s != 0)
+ {
+ uschar *ss = parse_find_address_end(s, FALSE);
+ uschar *recipient,*errmess;
+ int terminator = *ss;
+ int start, end, domain;
+
+ /* Temporarily terminate the string at this point, and extract the
+ operative address within. */
+
+ *ss = 0;
+ recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
+ *ss = terminator;
+
+ /* If we found a valid recipient that has a domain, compare it with the
+ envelope recipient. Local parts are compared case-sensitively, domains
+ case-insensitively. By comparing from the start with length "domain", we
+ include the "@" at the end, which ensures that we are comparing the whole
+ local part of each address. */
+
+ if (recipient != NULL && domain != 0)
+ {
+ found = Ustrncmp(recipient, address, domain) == 0 &&
+ strcmpic(recipient + domain, address + domain) == 0;
+ if (found) break;
+ }
+
+ /* Advance to the next address */
+
+ s = ss + (terminator? 1:0);
+ while (isspace(*s)) s++;
+ } /* Next address */
+ } /* Next header (if found is false) */
+
+ if (!found) return FAIL;
+ } /* Next recipient */
+
+return OK;
+}
+
+