chacha20: don't panic encrypting the final blocks

Certain operations with counter values close to overflowing were causing
an unnecessary panic, which was reachable due to the SetCounter API and
actually observed in QUIC.

Tests by lukechampine <luke.champine@gmail.com> from CL 220591.

Fixes golang/go#37157

Relanding of CL 224279, which was broken on multi-block buffers.
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/224279
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>

Change-Id: Ia382c6f62ae49ffe257b67f7b794e8d7124d981e
(cherry picked from commit 1c2c788b11ecf76cd7fbd7bba62146eb7082bdd8)
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/229119
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
2 files changed
tree: af68368f85a7cfa491e603f1b126171507b35520
  1. .gitattributes
  2. .gitignore
  3. AUTHORS
  4. CONTRIBUTING.md
  5. CONTRIBUTORS
  6. LICENSE
  7. PATENTS
  8. README.md
  9. acme/
  10. argon2/
  11. bcrypt/
  12. blake2b/
  13. blake2s/
  14. blowfish/
  15. bn256/
  16. cast5/
  17. chacha20/
  18. chacha20poly1305/
  19. codereview.cfg
  20. cryptobyte/
  21. curve25519/
  22. ed25519/
  23. go.mod
  24. go.sum
  25. hkdf/
  26. internal/
  27. md4/
  28. nacl/
  29. ocsp/
  30. openpgp/
  31. otr/
  32. pbkdf2/
  33. pkcs12/
  34. poly1305/
  35. ripemd160/
  36. salsa20/
  37. scrypt/
  38. sha3/
  39. ssh/
  40. tea/
  41. twofish/
  42. xtea/
  43. xts/
README.md

Go Cryptography

This repository holds supplementary Go cryptography libraries.

Download/Install

The easiest way to install is to run go get -u golang.org/x/crypto/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/crypto.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the crypto repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/crypto:” in the subject line, so it is easy to find.

Note that contributions to the cryptography package receive additional scrutiny due to their sensitive nature. Patches may take longer than normal to receive feedback.