tree b87445165b0af4cbf2cdec215f4f720e1e9d4802
parent ddd5ba78a949c5458aad9f7c3f19d214a2e8338e
author David Benjamin <davidben@google.com> 1491931471 -0400
committer Adam Langley <agl@google.com> 1492036065 +0000

Constrain RSA bit sizes.

The FIPS RSA generation algorithm is unkind to keys with funny bit
sizes. Odd numbers of bits are especially inconvenient, but the sqrt(2)
bound is much simpler if the key size is a multiple of 128 (thus giving
prime sizes a multiple of 64, so the sqrt(2) bound is easier to work
with).

Also impose a minimum RSA key size. 255-bit RSA is far too small as it
is and gives small enough primes that the p-q FIPS bound (2^(n/2-100))
starts risking underflow.

Change-Id: I4583c90b67385e53641ccee9b29044e79e94c920
Reviewed-on: https://boringssl-review.googlesource.com/14947
Reviewed-by: Adam Langley <agl@google.com>