Normalize RSA private component widths.

d, dmp1, dmq1, and iqmp have private magnitudes. This is awkward because
the RSAPrivateKey serialization leaks the magnitudes. Do the best we can
and fix them up before any RSA operations.

This moves the piecemeal BN_MONT_CTX_set_locked into a common function
where we can do more complex canonicalization on the keys.  Ideally this
would be done on key import, but the exposed struct (and OpenSSL 1.1.0's
bad API design) mean there is no single point in time when key import is

Also document the constraints on RSA_set0_* functions. (These
constraints aren't new. They just were never documented before.)

Update-Note: If someone tried to use an invalid RSA key where d >= n,
   dmp1 >= p, dmq1 >= q, or iqmp >= p, this may break. Such keys would not
   have passed RSA_check_key, but it's possible to manually assemble
   keys that bypass it.
Bug: 232
Change-Id: I421f883128952f892ac0cde0d224873a625f37c5
Commit-Queue: David Benjamin <>
CQ-Verified: CQ bot account: <>
Reviewed-by: Adam Langley <>
2 files changed
tree: eaf3d0c093ba963b4d43c4629eff29a1673b1b51
  1. .clang-format
  2. .github/
  3. .gitignore
  6. CMakeLists.txt
  14. codereview.settings
  15. crypto/
  16. decrepit/
  17. fipstools/
  18. fuzz/
  19. include/
  20. infra/
  21. sources.cmake
  22. ssl/
  23. third_party/
  24. tool/
  25. util/


BoringSSL is a fork of OpenSSL that is designed to meet Google's needs.

Although BoringSSL is an open source project, it is not intended for general use, as OpenSSL is. We don't recommend that third parties depend upon it. Doing so is likely to be frustrating because there are no guarantees of API or ABI stability.

Programs ship their own copies of BoringSSL when they use it and we update everything as needed when deciding to make API changes. This allows us to mostly avoid compromises in the name of compatibility. It works for us, but it may not work for you.

BoringSSL arose because Google used OpenSSL for many years in various ways and, over time, built up a large number of patches that were maintained while tracking upstream OpenSSL. As Google's product portfolio became more complex, more copies of OpenSSL sprung up and the effort involved in maintaining all these patches in multiple places was growing steadily.

Currently BoringSSL is the SSL library in Chrome/Chromium, Android (but it's not part of the NDK) and a number of other apps/programs.

There are other files in this directory which might be helpful: