I found an earlier reference for an algorithm for the optimized
computation of n0 that is very similar to the one in the "Montgomery
Multiplication" paper cited in the comments. Add a reference to it.
Henry S. Warren, Jr. pointed out that his "Montgomery Multiplication"
paper is not a chapter of his book, but a supplement to the book.
Correct the reference to it.
Change-Id: Iadeb148c61ce646d1262ccba0207a31ebdad63e9
Reviewed-on: https://boringssl-review.googlesource.com/10480
Reviewed-by: Adam Langley <agl@google.com>
Simplify the calculation of the Montgomery constants in
|BN_MONT_CTX_set|, making the inversion constant-time. It should also
be faster by avoiding any use of the |BIGNUM| API in favor of using
only 64-bit arithmetic.
Now it's obvious how it works. /s
Change-Id: I59a1e1c3631f426fbeabd0c752e0de44bcb5fd75
Reviewed-on: https://boringssl-review.googlesource.com/9031
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
