Hello!
I've used cryptsetup for a while now and started looking at the code. I
thought I'd share some additional error checks.
I noticed that when a new master key is generated (when doing
luksFormat) a call to getRandom did not check the return value. If
getRandom were to fail, the master key would not be set (or set to the
uninitialized memory previously allocated), but aside from an error
message the program would continue as if nothing happened.
The patch merely checks the return value of getRandom and fails if
getRandom fails. I also removed an unused variable in the getRandom
function itself. In that function there were two variables r, one
shadowing the other, so I removed one which wasn't used.
The change is fairly simple, it compiles and "make test" in the luks
sub-directory succeeds as far as I can tell, but I haven't tested it
further.
Regards,
Erik Edin
Index: lib/setup.c
===================================================================
--- lib/setup.c (revision 58)
+++ lib/setup.c (arbetskopia)
@@ -390,7 +390,7 @@
}
mk = LUKS_generate_masterkey(options->key_size);
- if(NULL == mk) return -ENOMEM;
+ if(NULL == mk) return -ENOMEM; // FIXME This may be misleading, since we don't know what went wrong
#ifdef LUKS_DEBUG
#define printoffset(entry) logger(options, CRYPT_LOG_ERROR, ("offset of " #entry " = %d\n", (char *)(&header.entry)-(char *)(&header))
Index: luks/random.c
===================================================================
--- luks/random.c (revision 58)
+++ luks/random.c (arbetskopia)
@@ -23,8 +23,6 @@
closeRandom */
int getRandom(char *buf, size_t len)
{
- int r = 0;
-
if(openRandom() == -1) {
perror("getRandom:");
return -EINVAL;
@@ -37,7 +35,7 @@
}
len-= r; buf += r;
}
- return r;
+ return 0;
}
void closeRandom() {
Index: luks/keymanage.c
===================================================================
--- luks/keymanage.c (revision 58)
+++ luks/keymanage.c (arbetskopia)
@@ -50,6 +50,7 @@
struct luks_masterkey *LUKS_alloc_masterkey(int keylength)
{
struct luks_masterkey *mk=malloc(sizeof(*mk) + keylength);
+ if(NULL == mk) return NULL;
mk->keyLength=keylength;
return mk;
}
@@ -66,7 +67,13 @@
struct luks_masterkey *LUKS_generate_masterkey(int keylength)
{
struct luks_masterkey *mk=LUKS_alloc_masterkey(keylength);
- getRandom(mk->key,keylength);
+ if(NULL == mk) return NULL;
+
+ int r = getRandom(mk->key,keylength);
+ if(r < 0) {
+ LUKS_dealloc_masterkey(mk);
+ return NULL;
+ }
return mk;
}
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