Skip signature hash verification for X509 signatures

[onak.git] / sigcheck.c

diff --git a/sigcheck.c b/sigcheck.c
index 900d3514fab414bd30ee85580b58a5c7108c9067..3ee8d3959e0e2db27e1c8c264d4b631cdec22896 100644 (file)
--- a/sigcheck.c
+++ b/sigcheck.c
@@ -20,6 +20,7 @@
 #include <stdint.h>
 
 #include "config.h"
+#include "decodekey.h"
 #include "keyid.h"
 #include "keystructs.h"
 #include "log.h"
@@ -108,6 +109,32 @@ int check_packet_sighash(struct openpgp_publickey *key,
        case 4:
                hashtype = sig->data[3];
 
+               /* Check to see if this is an X509 based signature */
+               if (sig->data[2] == 0 || sig->data[2] == 100) {
+                       size_t len;
+
+                       keyid = 0;
+                       len = parse_subpackets(&sig->data[4], &keyid, NULL);
+                       if (keyid == 0 &&
+                                       /* No unhashed data */
+                                       sig->data[4 + len] == 0 &&
+                                       sig->data[5 + len] == 0 &&
+                                       /* Dummy 0 checksum */
+                                       sig->data[6 + len] == 0 &&
+                                       sig->data[7 + len] == 0 &&
+                                       /* Dummy MPI of 1 */
+                                       sig->data[8 + len] == 0 &&
+                                       sig->data[9 + len] == 1 &&
+                                       sig->data[10 + len] == 1) {
+                               get_keyid(key, &keyid);
+                               logthing(LOGTHING_DEBUG,
+                                       "Skipping X509 signature on 0x%016"
+                                       PRIX64,
+                                       keyid);
+                               return -1;
+                       }
+               }
+
                if (packet != NULL) {
                        if (packet->tag == OPENPGP_PACKET_PUBLICSUBKEY) {
                                packetheader[0] = 0x99;