diff --git a/src/dnssec.c b/src/dnssec.c index a106fa5..8851492 100644 --- a/src/dnssec.c +++ b/src/dnssec.c @@ -250,31 +250,68 @@ static int check_date_range(unsigned long date_start, unsigned long date_end) && serial_compare_32(curtime, date_end) == SERIAL_LT; } + /* Sort RRs within a RRset in canonical order, according to RFC4034, ยง6.3 Notice that the RRDATA sections have been already normalized, so a memcpy is sufficient. NOTE: r1/r2 point immediately after the owner name. */ + +struct { + struct dns_header *header; + size_t pktlen; +} rrset_canonical_order_ctx; + static int rrset_canonical_order(const void *r1, const void *r2) { - int r1len, r2len, res; - const unsigned char *pr1=*(unsigned char**)r1, *pr2=*(unsigned char**)r2; + size_t r1len, r2len; + int rrtype, i; + unsigned char *pr1=*(unsigned char**)r1, *pr2=*(unsigned char**)r2; + unsigned char tmp1[MAXCDNAME], tmp2[MAXCDNAME]; /* TODO: use part of daemon->namebuff */ - pr1 += 8; pr2 += 8; + #define ORDER(buf1,len1, buf2,len2) \ + do { \ + int res = memcmp(buf1, buf2, MIN(len1,len2)); \ + if (res != 0) return res; \ + if (len1 < len2) return -1; \ + if (len1 > len2) return 1; \ + } while (0) + + GETSHORT(rrtype, pr1); + pr1 += 6; pr2 += 8; GETSHORT(r1len, pr1); GETSHORT(r2len, pr2); - /* Lexicographically compare RDATA (thus, if equal, smaller length wins) */ - res = memcmp(pr1, pr2, MIN(r1len, r2len)); - if (res == 0) - { - if (r1len < r2len) - return -1; - else - /* NOTE: RFC2181 says that an RRset is not allowed to contain duplicate - records. If it happens, it is a protocol error and anything goes. */ - return 1; - } - - return res; + if (rrtype < countof(rdata_description)) + for (i = 0; rdata_description[rrtype][i] != RDESC_END; ++i) + { + int d = rdata_description[rrtype][i]; + if (d == RDESC_DOMAIN) + { + int dl1 = process_domain_name(rrset_canonical_order_ctx.header, rrset_canonical_order_ctx.pktlen, + &pr1, &r1len, tmp1, PWN_EXTRACT); + int dl2 = process_domain_name(rrset_canonical_order_ctx.header, rrset_canonical_order_ctx.pktlen, + &pr2, &r2len, tmp2, PWN_EXTRACT); + /* TODO: how do we handle errors, that is dl1==0 or dl2==0 ? */ + assert(dl1 != 0); + assert(dl2 != 0); + ORDER(tmp1, dl1, tmp2, dl2); + } + else + { + ORDER(pr1, d, pr2, d); + pr1 += d; pr2 += d; + r1len -= d; r2len -= d; + } + } + + /* Order the rest of the record. */ + ORDER(pr1, r1len, pr2, r2len); + + /* If we reached this point, the two RRs are identical. + RFC2181 says that an RRset is not allowed to contain duplicate + records. If it happens, it is a protocol error and anything goes. */ + return 1; + + #undef ORDER } typedef struct PendingRRSIGValidation @@ -319,6 +356,7 @@ static void verifyalg_add_data_domain(VerifyAlgCtx *alg, char* name) alg->vtbl->add_data(alg, "\0", 1); } + /* Pass a DNS domain name in wire format through a hash function. Returns the total number of bytes passed through the function or 0 in case of errors. Updates the rdata pointer moving it further within the RR. @@ -476,6 +514,8 @@ static int begin_rrsig_validation(struct dns_header *header, size_t pktlen, } /* Sort RRset records in canonical order. */ + rrset_canonical_order_ctx.header = header; + rrset_canonical_order_ctx.pktlen = pktlen; qsort(rrset, rrsetidx, sizeof(void*), rrset_canonical_order); /* Skip through the signer name; we don't extract it right now because