• Richard van der Hoff's avatar
    Fix Ed25519 keypair generation · 0c462cff
    Richard van der Hoff authored
    Ed25519 private keys, it turns out, have 64 bytes, not 32.
    We were previously generating only 32 bytes (which is all that is required to
    generate the public key), and then using the public key as the upper 32 bytes
    when generating the per-message session key. This meant that everything
    appeared to work, but the security of the private key was severely compromised.
    By way of fixes:
     * Use the correct algorithm for generating the Ed25519 private key, and store
       all 512 bits of it.
     * Update the account pickle format and refuse to load the old format (since we
       should consider it compromised).
     * Bump the library version, and add a function to retrieve the library
       version, so that applications can verify that they are linked against a
       fixed version of the library.
     * Remove the curve25519_{sign, verify} functions which were unused and of
       dubious quality.