* Keypair: implement clone()
This was not implemented upstream in ed25519-dalek to force everyone to
think twice before creating another copy of a potentially sensitive
private key in memory.
See https://github.com/dalek-cryptography/ed25519-dalek/issues/76
However, there are now 9 instances of
Keypair::from_bytes(&keypair.to_bytes())
in the solana codebase and it would be preferable to have a function.
In particular since this also comes up when writing programs and can
cause users to either start messing with lifetimes or discover the
from_bytes() workaround themselves.
This patch opts to not implement the Clone trait. This avoids automatic
use in order to preserve some of the original "let developers think
twice about this" intention.
* Use Keypair::clone
Will Hickey
Christian Kamm
Michael Vines
Brooks Prumo