Patch to add ECKey#toASN1 to convert it back into the standard format

[mikehearn]

Originally reported on Google Code with ID 8

This patch adds a toASN1 method to go along with ECKey#fromASN1.

The produced byte sequence is not identical, it is longer, because of the way BountyCastle
adds padding to the eliptic curve parameters.
But the attached unit test confirms that it can be read again and produces the same
key.

I planned to use this instead of Object serialization, but it seems that the ASN1 is
actually longer than the Java serialization, because it also includes the curve description,
which the code assumes to be fixed.

https://github.com/thiloplanz/bitcoinj/commit/1d1f32699c4d554ed66c33f1cc38d0fd1eaeeed5

I have submitted the electronic version of your CLA.

Reported by thiloplanz on 2011-03-31 13:07:44

[mikehearn]

Brilliant, thanks. The change looks great. I will try and merge this in today. If I
don't it'll have to wait a week as tomorrow I'm off on vacation.

Reported by hearn@google.com on 2011-03-31 13:21:53

• Labels added: Type-Enhancement
• Labels removed: Type-Defect

[mikehearn]

This issue was closed by revision r51.

Reported by hearn@google.com on 2011-03-31 20:38:40

• Status changed: Fixed