Reject iterationCount == 0 when parsing PBKDF2-params.

Previously a value of 0 would be accepted and intepreted as equivalent
to 1. This contradicts RFC 2898 which defines:

     iterationCount INTEGER (1..MAX),

BUG=https://crbug.com/534961

Change-Id: I89623980f99fde3ca3780880d311955d3f6fe0b5
Reviewed-on: https://boringssl-review.googlesource.com/5971
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
1 file changed