Who is creating non-DER signatures?

[TierNolan]

Question, if these address contain too many characters, why don't miners reject the txs or blocks that contain them.  Would the database schema limit the output field to 40 char?

They simply pass them to OpenSSL.  OpenSSL says that the keys are ok, so the miner accepts the block.

[Mike Hearn]

The Java library from two years ago is bitcoinj and the author was me. I tried making Bouncy Castle produced negative r/s values a while ago by letting it generate signatures over random data in a tight loop, but it never created any. Maybe we should try the same thing with bitcoinjs

[Pieter Wuille]

Some old versions of bitcoinjs and Armory are known to have produced non-DER signatures, but both authors are aware of this, and fixed their code more than half a year ago, afaik.

[Mike Hearn]

Perhaps the iPhone app was never updated.