Merge lp:~stefan.goetz-deactivatedaccount/hipl/dh-key-generation-fixes into lp:hipl

[Stefan Götz]

Fixes an out-of-bounds access to an array which prevented compiling HIPL at optimization level 3

[Miika Komu (miika-iki)]

Tested and seems to work. Thanks Stefan!

review: Approve

=== modified file 'hipd/dh.c'
--- hipd/dh.c	2010-10-15 15:29:14 +0000
+++ hipd/dh.c	2010-11-01 16:13:50 +0000
@@ -40,6 +40,15 @@
 #include "lib/core/debug.h"
 #include "dh.h"
 
+/**
+ * This table holds Diffie-Hellman values used during HIP BEXs.
+ * These values are generated when the HIP daemon starts and valid for its
+ * lifetime.
+ * Each array element corresponds to a DH value of a specific DH group.
+ * The valid groups are defined in RFC 5201, section 5.2.6.
+ * This array is indexed by the Group ID value defined in the RFC.
+ * Note that this means that the array element at index 0 is thus unused.
+ */
 DH *dh_table[HIP_MAX_DH_GROUP_ID] = {0};
 
 /**
@@ -53,6 +62,12 @@
     int res;
     DH *tmp;
 
+    if (group_id <= 0 || group_id >= HIP_MAX_DH_GROUP_ID) {
+        HIP_ERROR("The Group ID %d is invalid\n", group_id);
+        res = -1;
+        goto err_free;
+    }
+
     /*
      * First check that we have the key available.
      * Then encode it into the buffer
@@ -105,6 +120,11 @@
     int err = 0;
     DH *tmp;
 
+    if (group_id <= 0 || group_id >= HIP_MAX_DH_GROUP_ID) {
+        HIP_ERROR("The Group ID %d is invalid\n", group_id);
+        return -1;
+    }
+
     /*
      * First check that we have the key available.
      * Then encode it into the buffer
@@ -146,7 +166,7 @@
     maxmask  = (1 << (HIP_MAX_DH_GROUP_ID + 1)) - 1;
     bitmask &= maxmask;
 
-    for (i = 1; i <= HIP_MAX_DH_GROUP_ID; i++) {
+    for (i = 1; i < HIP_MAX_DH_GROUP_ID; i++) {
         if (bitmask & (1 << i)) {
             tmp = hip_generate_dh_key(i);
             if (!tmp) {