nss/nss-703658.patch
Elio Maldonado c409805d45 - Fix crmf hard-coded maximum size for wrapped private keys (#703658)
- Use the safer bound off
- ( ( RSA_MAX_MODULUS_BITS / 8 ) *8 ) = RSA_MAX_MODULUS_BITS
- which will accomodate other algorithms
2011-05-17 09:07:55 -07:00

48 lines
1.7 KiB
Diff

Index: mozilla/security/nss/lib/crmf/crmfi.h
===================================================================
RCS file: /cvsroot/mozilla/security/nss/lib/crmf/crmfi.h,v
retrieving revision 1.4
diff -u -u -r1.4 crmfi.h
--- mozilla/security/nss/lib/crmf/crmfi.h 15 Jan 2011 19:47:11 -0000 1.4
+++ mozilla/security/nss/lib/crmf/crmfi.h 11 May 2011 20:06:26 -0000
@@ -46,10 +46,38 @@
#include "secasn1.h"
#include "crmfit.h"
#include "secerr.h"
+#include "blapit.h"
#define CRMF_DEFAULT_ARENA_SIZE 1024
-#define MAX_WRAPPED_KEY_LEN 2048
+/*
+ * Explanation for the definition of MAX_WRAPPED_KEY_LEN:
+ *
+ * It's used for internal buffers to transport a wrapped private key.
+ * The value is in BYTES.
+ * We want to define a reasonable upper bound for this value.
+ * Ideally this could be calculated, but in order to simplify the code
+ * we want to estimate the maximum requires size.
+ * See also mozilla bug 655850 for the full explanation.
+ *
+ * We know the largest wrapped keys are RSA keys.
+ * We'll estimate the maximum size needed for wrapped RSA keys,
+ * and assume it's sufficient for wrapped keys of any type we support.
+ *
+ * The maximum size of RSA keys in bits is defined elsewhere as
+ * RSA_MAX_MODULUS_BITS
+ *
+ * The idea is to define MAX_WRAPPED_KEY_LEN based on the above.
+ *
+ * A wrapped RSA key requires about
+ * ( ( RSA_MAX_MODULUS_BITS / 8 ) * 5.5) + 65
+ * bytes.
+ *
+ * Therefore, a safe upper bound is:
+ * ( ( RSA_MAX_MODULUS_BITS / 8 ) *8 ) = RSA_MAX_MODULUS_BITS
+ *
+ */
+#define MAX_WRAPPED_KEY_LEN RSA_MAX_MODULUS_BITS
#define CRMF_BITS_TO_BYTES(bits) (((bits)+7)/8)
#define CRMF_BYTES_TO_BITS(bytes) ((bytes)*8)