At 12:21 AM 6/22/2015, Michael StJohns wrote:
>Hmm...
>
>It is possible to randomly generate a prime which is expressed in less than
>the full number of provided bytes so it is possible (and legal) for
>sourceLength to be less than or equal to destination length. What should
>probably be checked here though is :
*sigh*
The following should have been :
int off = sourceLength;
if (sourceLength > destinationLength) {
if (sourceLength > (destinationLength +1)) {
return -1;
}
off++;
sourceLength == destinationLength;
}
If you're taking a 65 byte big endian representation and trimming the sign byte
to get 64 bytes, that's OK. If you're taking a 66 byte representation and
trying to stuff it into 64 bytes, you're throwing away 1 byte of meaningful
data.
>if (sourceLength > destinationLength) {
> return -1;
>}
>
>(E.g. if you're trying to stuff N bytes in an N-1 length array it will be bad).
>
>For the rest, it seems clumsy to do it that way (the loop and if statement) -
>instead maybe do an
>
>int off = sourceLength;
>
>for (int i = 0; i < sourceLength; i++) {
> destination[i] = sourceBytes[--off]; // note the pre decrement!
>}
>
>if (sourceLength < destinationLength) {
> memset (destination + sourceLength, 0, destinationLength - sourceLength);
>}
>
>
>To copy and then clear.
>
>And then
>
>return destinationLength;
*sigh*
return sourceLength;
>Mike
>
>
>
>
>
>At 06:04 AM 6/19/2015, Weijun Wang wrote:
>>I might have found a reason for SunMSCAPI crash
>>
>> http://cr.openjdk.java.net/~weijun/8023546/webrev.00
>>
>>Before this fix, the native function convertToLittleEndian() fails if you
>>want to convert a 63 byte array to a 64 byte one. However, I observed that
>>when a 1024 bit RSA private key is generated, its prime exponent p can be
>>only 63 bytes long. Function is updated to accept this case.
>>
>>I'm not a cryptographer so if you believe the p must be of 64 bytes long
>>please tell me.
>>
>>Thanks
>>Max
