+Adapted from https://git.exim.org/exim.git/patch/79670d3c32ccb37fe06f25d8192943b58606a32a
+
+Reference: https://bugs.exim.org/show_bug.cgi?id=3054
+--
+From 79670d3c32ccb37fe06f25d8192943b58606a32a Mon Sep 17 00:00:00 2001
+From: Jeremy Harris <jgh146exb@wizmail.org>
+Date: Fri, 17 Nov 2023 16:55:17 +0000
+Subject: [PATCH] Lookups: Fix dnsdb lookup of multi-chunk TXT. Bug 3054
+
+Broken=by: f6b1f8e7d642
+
+--- a/src/lookups/dnsdb.c
++++ b/src/lookups/dnsdb.c
+@@ -387,38 +387,31 @@ while ((domain = string_nextinlist(&keystring, &sep, NULL, 0)))
+ }
+
+ /* Other kinds of record just have one piece of data each, but there may be
+- several of them, of course. */
++ several of them, of course. TXT & SPF can have data in multiple chunks. */
+
+ if (yield->ptr) yield = string_catn(yield, outsep, 1);
+
+ if (type == T_TXT || type == T_SPF)
+- {
+- if (!outsep2) /* output only the first item of data */
++ for (unsigned data_offset = 0; data_offset + 1 < rr->size; )
+ {
+- uschar n = (rr->data)[0];
+- /* size byte + data bytes must not excced the RRs length */
+- if (n + 1 <= rr->size)
+- yield = string_catn(yield, US (rr->data+1), n);
++ uschar chunk_len = (rr->data)[data_offset];
++ int remain;
++
++ if (outsep2 && *outsep2 && data_offset != 0)
++ yield = string_catn(yield, outsep2, 1);
++
++ /* Apparently there are resolvers that do not check RRs before passing
++ them on, and glibc fails to do so. So every application must...
++ Check for chunk len exceeding RR */
++
++ remain = rr->size - ++data_offset;
++ if (chunk_len > remain)
++ chunk_len = remain;
++ yield = string_catn(yield, US ((rr->data) + data_offset), chunk_len);
++ data_offset += chunk_len;
++
++ if (!outsep2) break; /* output only the first chunk of the RR */
+ }
+- else
+- for (unsigned data_offset = 0; data_offset < rr->size; )
+- {
+- uschar chunk_len = (rr->data)[data_offset];
+- int remain = rr->size - data_offset;
+-
+- /* Apparently there are resolvers that do not check RRs before passing
+- them on, and glibc fails to do so. So every application must...
+- Check for chunk len exceeding RR */
+-
+- if (chunk_len > remain)
+- chunk_len = remain;
+-
+- if (*outsep2 && data_offset != 0)
+- yield = string_catn(yield, outsep2, 1);
+- yield = string_catn(yield, US ((rr->data) + ++data_offset), --chunk_len);
+- data_offset += chunk_len;
+- }
+- }
+ else if (type == T_TLSA)
+ if (rr->size < 3)
+ continue;
projects / aports.git / commitdiff