On 18/06/2020 17:27, Ronny Meeus wrote: > Op do 18 jun. 2020 om 18:13 schreef Salz, Rich <rsalz@xxxxxxxxxx>: >> >>> BN_bin2bn assumes that the size of a BN_ULONG (the type of a bn->d) is >> BN_BYTES. You have already told us that sizeof(*d) is 4. So BN_BYTES >> should also be 4. If BN_BYTES is being incorrectly set to 8 on your >> platform then that would explain the discrepancy. Can you check? >> >> This seems HIGHLY likely since Ronny said earlier that the same config/toolchain is used for 32bit userspace and 64bit kernel, right? >> > > I used the following print statement so the sizeof is actual of the *d > and not of the pointer :-). > printf("BN_num data (size=%d top=%d neg=%d flags=%d, sizeof(*d)=%d) > BN_BYTES=%d: ", rnd->dmax, rnd->top, rnd->neg, rnd->flags, > sizeof(*rnd->d), BN_BYTES); > > The output clearly shows that BN_BYTES is 8: > > BN_num data (size=24 top=24 neg=0 flags=13, sizeof(*d)=4) BN_BYTES=8: > efe838eb2cf627a7cf1944d5969e17602474f949d4e04f33263e49cdc9917b5f4f71f4f27eb06b2f41930dbac791ded7fae69fa604ec65686b412ef048e91cfd8c976e74ff237112406371b6cb2770588328f8db400718366665b6bca733a19c > > I think we are getting close to the root-cause here ... Ok, this is clearly why you're getting strange results. The question is why is sizeof(*d) different to the value of BN_BYTES? What Configure target did you use to build for this platform? Also, take a look at the end of the file include/openssl/opensslconf.h You should see a section at the end that looks like this: /* Only one for the following should be defined */ # define SIXTY_FOUR_BIT_LONG # undef SIXTY_FOUR_BIT # undef THIRTY_TWO_BIT This file is generated, and depending on what Configure has decided is appropriate for your platform one of the above 3 should be defined, and the other 2 undef'd. What does it show for your platform? Matt