migrate from the other repo.

.gitignore

@@ -0,0 +1,2 @@
+dist/*
+trustedcoin

Makefile

@@ -0,0 +1,3 @@
+dist: $(shell find . -name "*.go")
+	mkdir -p dist
+	gox -ldflags="-s -w" -tags="full" -osarch="darwin/amd64 linux/386 linux/amd64 linux/arm freebsd/amd64" -output="dist/trustedcoin_{{.OS}}_{{.Arch}}"

README.md

@@ -0,0 +1,40 @@
+## The `trustedcoin` plugin
+
+A plugin that uses block explorers (blockstream.info, mempool.space, blockchair.com and blockchain.info) as backends instead of your own Bitcoin node.
+
+This isn't what you should be doing, but sometimes you may need it.
+
+(Remember this will download all blocks c-lightning needs from blockchain.info or blockchair.com in raw, hex format.)
+
+## How to install
+
+This is distributed as a single binary for your delight (or you can compile it yourself with `go get`, or ask me for binaries for other systems if you need them).
+
+[Download it](https://github.com/fiatjaf/trustedcoin/releases), call `chmod +x <binary>` and put it in `~/.lightning/plugins` (create that directory if it doesn't exist).
+
+You only need the binary you can get in [the releases page](https://github.com/fiatjaf/trustedcoin/releases), nothing else.
+
+Then add the following line to your `~/.lightning/config` file:
+
+```
+disable-plugin=bcli
+```
+
+This disables the default Bitcoin backend plugin so `trustedcoin` can take its place.
+
+### Extra: how to bootstrap a Lightning node from scratch, without Bitcoin Core, on Ubuntu amd64
+
+```
+add-apt-repository ppa:lightningnetwork/ppa
+apt update
+apt install lightningd
+mkdir -p ~/.lightning/plugins
+echo 'disable-plugin=bcli' >> .lightning/config
+cd ~/.lightning/plugins
+wget https://github.com/fiatjaf/lightningd-gjson-rpc/releases/download/trustedcoin-v0.2.4/trustedcoin_linux_amd64
+chmod +x trustedcoin_linux_amd64
+cd
+lightningd
+```
+
+## Built with [![GoDoc](https://godoc.org/github.com/fiatjaf/lightningd-gjson-rpc?status.svg)](https://godoc.org/github.com/fiatjaf/lightningd-gjson-rpc)

estimatefees.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+)
+
+type EstimatedFees struct {
+	Opening         *int `json:"opening"`
+	MutualClose     *int `json:"mutual_close"`
+	UnilateralClose *int `json:"unilateral_close"`
+	DelayedToUs     *int `json:"delayed_to_us"`
+	HTLCResolution  *int `json:"htlc_resolution"`
+	Penalty         *int `json:"penalty"`
+	MinAcceptable   *int `json:"min_acceptable"`
+	MaxAcceptable   *int `json:"max_acceptable"`
+}
+
+func getFeeRatesFromEsplora() (feerates map[string]float64, err error) {
+	for _, endpoint := range esploras() {
+		w, errW := http.Get(endpoint + "/fee-estimates")
+		if errW != nil {
+			err = errW
+			continue
+		}
+		defer w.Body.Close()
+
+		if w.StatusCode >= 300 {
+			err = errors.New(endpoint + " error: " + w.Status)
+			return
+		}
+
+		err = json.NewDecoder(w.Body).Decode(&feerates)
+		return
+	}
+
+	err = errors.New("none of the esploras returned usable responses")
+	return
+}

getblock.go

@@ -0,0 +1,155 @@
+package main
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strings"
+
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcutil"
+)
+
+var heightCache = make(map[int64]string)
+
+func getBlock(height int64) (block, hash string, err error) {
+	hash, err = getHash(height)
+	if err != nil {
+		return
+	}
+	if hash == "" /* block unavailable */ {
+		return
+	}
+
+	for _, try := range []func(string) (string, error){
+		blockFromBlockchainInfo,
+		blockFromBlockchair,
+	} {
+		blockhex, errW := try(hash)
+		if errW != nil || blockhex == "" {
+			err = errW
+			continue
+		}
+
+		// verify and hash
+		blockbytes, errW := hex.DecodeString(blockhex)
+		if errW != nil {
+			err = errW
+			continue
+		}
+
+		blockparsed, errW := btcutil.NewBlockFromBytes(blockbytes)
+		if errW != nil {
+			err = errW
+			continue
+		}
+		header := blockparsed.MsgBlock().Header
+
+		blockhash := hex.EncodeToString(reverseHash(blockparsed.Hash()))
+		if blockhash != hash {
+			err = fmt.Errorf("fetched block hash %s doesn't match expected %s",
+				blockhash, hash)
+			continue
+		}
+
+		prevHash := hex.EncodeToString(header.PrevBlock[:])
+		if cachedPrevHash, ok := heightCache[height-1]; ok {
+			if prevHash != cachedPrevHash {
+				// something is badly wrong with this block
+				err = fmt.Errorf("block %d (%s): prev block hash %d (%s) doesn't match what we know from previous block %d (%s)", height, blockhash, height-1, prevHash, height-1, cachedPrevHash)
+				continue
+			}
+		}
+
+		delete(heightCache, height)
+		return blockhex, hash, nil
+	}
+
+	return
+}
+
+func getHash(height int64) (hash string, err error) {
+	for _, endpoint := range esploras() {
+		w, errW := http.Get(fmt.Sprintf(endpoint+"/block-height/%d", height))
+		if errW != nil {
+			err = errW
+			continue
+		}
+		defer w.Body.Close()
+
+		if w.StatusCode >= 404 {
+			continue
+		}
+
+		data, errW := ioutil.ReadAll(w.Body)
+		if errW != nil {
+			err = errW
+			continue
+		}
+
+		hash = strings.TrimSpace(string(data))
+
+		if len(hash) > 64 {
+			err = errors.New("got something that isn't a block hash: " + hash[:64])
+			continue
+		}
+
+		heightCache[height] = hash
+
+		return hash, nil
+	}
+
+	return "", err
+}
+
+func blockFromBlockchainInfo(hash string) (string, error) {
+	w, err := http.Get(fmt.Sprintf("https://blockchain.info/block/%s?format=hex", hash))
+	if err != nil {
+		return "", fmt.Errorf("failed to get raw block %s from blockchain.info: %s", hash, err.Error())
+	}
+	defer w.Body.Close()
+
+	block, _ := ioutil.ReadAll(w.Body)
+	if len(block) < 100 {
+		// block not available here yet
+		return "", nil
+	}
+
+	return string(block), nil
+}
+
+func blockFromBlockchair(hash string) (string, error) {
+	w, err := http.Get("https://api.blockchair.com/bitcoin/raw/block/" + hash)
+	if err != nil {
+		return "", fmt.Errorf("failed to get raw block %s from blockchair.com: %s", hash, err.Error())
+	}
+	defer w.Body.Close()
+
+	var data struct {
+		Data map[string]struct {
+			RawBlock string `json:"raw_block"`
+		} `json:"data"`
+	}
+	err = json.NewDecoder(w.Body).Decode(&data)
+	if err != nil {
+		return "", err
+	}
+
+	if bdata, ok := data.Data[hash]; ok {
+		return bdata.RawBlock, nil
+	} else {
+		// block not available here yet
+		return "", nil
+	}
+}
+
+func reverseHash(hash *chainhash.Hash) []byte {
+	r := make([]byte, chainhash.HashSize)
+	for i, b := range hash {
+		r[chainhash.HashSize-i-1] = b
+	}
+	return r
+}

gettip.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"io/ioutil"
+	"net/http"
+	"strconv"
+)
+
+func getTip() (tip int64, err error) {
+	for _, endpoint := range esploras() {
+		w, errW := http.Get(endpoint + "/blocks/tip/height")
+		if errW != nil {
+			err = errW
+			continue
+		}
+		defer w.Body.Close()
+
+		data, errW := ioutil.ReadAll(w.Body)
+		if errW != nil {
+			err = errW
+			continue
+		}
+
+		tip, errW = strconv.ParseInt(string(data), 10, 64)
+		if errW != nil {
+			err = errW
+			continue
+		}
+
+		return tip, nil
+	}
+
+	return 0, err
+}

gettransaction.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+type UTXOResponse struct {
+	Amount *int64  `json:"amount"`
+	Script *string `json:"script"`
+}
+
+func getTransaction(txid string) (tx struct {
+	TXID string `json:"txid"`
+	Vout []struct {
+		ScriptPubKey string `json:"scriptPubKey"`
+		Value        int64  `json:"value"`
+	} `json:"vout"`
+}, err error) {
+	for _, endpoint := range esploras() {
+		w, errW := http.Get(endpoint + "/tx/" + txid)
+		if errW != nil {
+			err = errW
+			continue
+		}
+		defer w.Body.Close()
+
+		errW = json.NewDecoder(w.Body).Decode(&tx)
+		if errW != nil {
+			err = errW
+			continue
+		}
+
+		return tx, nil
+	}
+
+	return
+}

go.mod

@@ -0,0 +1,9 @@
+module github.com/fiatjaf/trustedcoin
+
+go 1.14
+
+require (
+	github.com/btcsuite/btcd v0.20.1-beta.0.20200515232429-9f0179fd2c46
+	github.com/btcsuite/btcutil v1.0.2
+	github.com/fiatjaf/lightningd-gjson-rpc v1.0.1
+)