message verify failed (sbot: invalid signature)

[cryptix]

There are still some edge cases around message verification:

caller=handler.go:112 module=sbot plugin=gossip handleConnect="fetchFeed hops failed" 
err="fetchFeed(@/02iw6SFEPIHl8nMkYSwcCgRWxiG6VP547Wcp1NW8Bo=.ed25519:4505):
message verify failed:
ssb Verify(@/02iw6SFEPIHl8nMkYSwcCgRWxiG6VP547Wcp1NW8Bo=.ed25519:4506):
could not verify message: sbot: invalid signature"

If you have the feed in question you can do this to reproduce the problem and get an extended diff:

$ cd ssb/message
$ npm i
$ node encode_test.js '@/02iw6SFEPIHl8nMkYSwcCgRWxiG6VP547Wcp1NW8Bo=.ed25519'
$ go test

2019/01/21 23:07:25 loaded 5366 messages from testdata.zip
--- FAIL: TestSignatureVerify (1.05s)
    signature_test.go:26: strings are not identical: 
        {
          "previous": "%N4UCoD60og80twWAv6cliXOAPfBcg2yU1bFxnMz4ElM=.sha256",
          "author": "@/02iw6SFEPIHl8nMkYSwcCgRWxiG6VP547Wcp1NW8Bo=.ed25519",
          "sequence": 4506,
          "timestamp": 1462418380624,
          "hash": "sha256",
          "content": {
            "type": "post",
            "text": "- http://research.microsoft.com/en-us/um/people/simonpj/Papers/financial-contracts/contracts-icfp.pdf\n\nopens with haskell and one-letter variable names. great start.\n\n> At this point, any red-blooded funtional programmer should start to foam at the mouth, yelling \"build a combinator library\". And indeed, that turns out to be not only possible, but tremendously bene\fu000cficial.\n\nok agree, way better than that powerpoint\n\n> `c7 = scaleK 100 (get (truncate t1 (one GBP)))`\n\nso the author says these are the four functions that make a contract that pays 100 GBP at time t1.\n\n> Why did we go to the trouble of de\fu000cfining zb in terms of four combinators, rather than making it primitive? Beause it turns out that `scaleK`, `get`, `truncate`, and `one` are all independently useful.\n\n\"it turns out\" instantiates a contract too, i think.\n\n> The temperature in Los Angeles can be objectively measured; but the value to me of insuring my house is subjective, and is not an observable. Observables are thus a diff\u000berent \"kind of thing\" from contracts, so we give them a di\u000bfferent type:\n\nnot sure i buy that syllogism...\n\n![legalese.png](&wWf1aNvgqvtWnu7fywNff2UALjcrsmKxK4RgePUixm4=.sha256)\n\nok sure\n\n![gibberish.png](&6/6P/avhWbg9GNVVZ8qqBatjMwwPEHil1mRm3uzuUxc=.sha256)\n\n:\\\n\n> Much of the subtlety in \fu000cfinancial contracts arises because the participants can exercise choices. We enapsulate choice in two primitive combinators, or and anytime. The former allows one to choose which of two contracts to acquire (this section), while the latter allows one to choose when to acquire it (Section 3.5).\n\nsure, why not\n\nthere is a second section about evaluation, which hopefully answers the burning questions this section raises (next msg)",
            "root": "%9NYn+97xLhIqI0oPdiWxOckPODa9X267553iFtEDH74=.sha256",
            "branch": "%N4UCoD60og80twWAv6cliXOAPfBcg2yU1bFxnMz4ElM=.sha256",
            "mentions": [
              {
                "link": "&wWf1aNvgqvtWnu7fywNff2UALjcrsmKxK4RgePUixm4=.sha256",
                "name": "legalese.png",
                "size": 135799,
                "type": "image/png"
              },
              {
                "link": "&6/6P/avhWbg9GNVVZ8qqBatjMwwPEHil1mRm3uzuUxc=.sha256",
                "name": "gibberish.png",
                "size": 53361,
                "type": "image/png"
              }
            ],
            "channel": "networks"
          }
        }
    require.go:794: 
                Error Trace:    signature_test.go:29
                Error:          Received unexpected error:
                                sbot: invalid signature
                                go.cryptoscope.co/ssb/message.Signature.Verify
                                        /home/cryptix/go/src/go.cryptoscope.co/ssb/message/signature.go:56
                                go.cryptoscope.co/ssb/message.TestSignatureVerify
                                        /home/cryptix/go/src/go.cryptoscope.co/ssb/message/signature_test.go:28
                                testing.tRunner
                                        /nix/store/1205i5sksik4dqlr85pphrrllmic9a9n-go-1.11.4/share/go/src/testing/testing.go:827
                                runtime.goexit
                                        /nix/store/1205i5sksik4dqlr85pphrrllmic9a9n-go-1.11.4/share/go/src/runtime/asm_amd64.s:1333
                Test:           TestSignatureVerify
                Messages:       verify failed
FAIL
exit status 1
FAIL    go.cryptoscope.co/ssb/message   1.241s

(The paste stripped the color encoding. The gist of the diff is should have \f but has \u000c)

There is another one of these involving float encoding documented in this thread: http://viewer.scuttlebot.io/%25ej5uaph%2BvBGQmX%2B9lFywOLzyZMbpBvZ5khm26ERdZbo%3D.sha256