ed25519: actually be compatible with RFC 8032

Most implementations, including this one, consider the private key to be
the concatenation of the initial 32-byte seed and the public key.
However the RFC 8032 formulation considers the "private key" to just be
the seed, which, in turn, means the upcoming draft-ietf-curdle-pkix
specification for embedding Ed25519 into PKCS#8 only stores the seed.

Exporting ed25519.PrivateKey to the seed is easy: key[:32]. Importing
the seed to ed25519.PrivateKey is not currently possible because the
logic is tied up in ed25519.GenerateKey. Split out
ed25519.NewKeyFromSeed for this, as well as an ed25519.PrivateKey.Seed
accessor to keep the abstraction consistent.

Change-Id: I4068eaf2073009dff3d84224aa145b56b59a5854
Reviewed-on: https://go-review.googlesource.com/115297
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2 files changed
tree: a1fce0da56dc3e75d7c8b36b6bbb73cfc697882e
  1. acme/
  2. argon2/
  3. bcrypt/
  4. blake2b/
  5. blake2s/
  6. blowfish/
  7. bn256/
  8. cast5/
  9. chacha20poly1305/
  10. cryptobyte/
  11. curve25519/
  12. ed25519/
  13. hkdf/
  14. internal/
  15. md4/
  16. nacl/
  17. ocsp/
  18. openpgp/
  19. otr/
  20. pbkdf2/
  21. pkcs12/
  22. poly1305/
  23. ripemd160/
  24. salsa20/
  25. scrypt/
  26. sha3/
  27. ssh/
  28. tea/
  29. twofish/
  30. xtea/
  31. xts/
  32. .gitattributes
  33. .gitignore
  34. AUTHORS
  35. codereview.cfg
  36. CONTRIBUTING.md
  37. CONTRIBUTORS
  38. LICENSE
  39. PATENTS
  40. README.md
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.