fedilogue/fedilogger/follow.go

package main

import (
	"bytes"
	"crypto/tls"
	"crypto/x509"

	"encoding/pem"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"strings"
	"time"

	"github.com/go-fed/httpsig"
)

func followInbox(inboxurl string) {
	matchset := re.FindStringSubmatch(inboxurl)
	if matchset == nil {
		logWarn("Unable to unregex request", inboxurl)
		return
	}
	inboxhostname := matchset[1]

	keyBytes, err := ioutil.ReadFile("keys/private.pem")
	if err != nil {
		log.Fatal(err)
	}

	pemBlock, _ := pem.Decode(keyBytes)
	if pemBlock == nil {
		log.Fatal("Invalid PEM format")
	}

	privateKey, err := x509.ParsePKCS1PrivateKey(pemBlock.Bytes)
	if err != nil {
		log.Fatal(err)
	}

	jsonRequest := fmt.Sprintf(`{"@context":["https://www.w3.org/ns/activitystreams","https://%[2]s/schemas/litepub-0.1.jsonld",{"@language":"und"}],"actor":"https://%[2]s/relay","cc":[],"id":"https://%[2]s/activities/bd0614f5-371d-4bd2-88b3-1ee12f7bf42a","object":"%[1]s","state":"pending","to":["%[1]s"],"type":"Follow"}`, inboxurl, settings.Hostname)

	//var jsonBytes []byte
	jsonBytes := []byte(jsonRequest)
	payload := bytes.NewReader(jsonBytes)

	prefs := []httpsig.Algorithm{httpsig.RSA_SHA256}
	digestAlgorithm := httpsig.DigestSha256
	headers := []string{httpsig.RequestTarget, "date", "host"}
	signer, _, err := httpsig.NewSigner(prefs, digestAlgorithm, headers, httpsig.Signature, 0)
	if err != nil {
		log.Fatal(err.Error())
	}

	req, err := http.NewRequest("POST", inboxurl, payload)
	if err != nil {
		log.Fatal(err.Error())
	}
	if payload != nil {
		req.Header.Add("content-type", "application/json")
	}
	req.Header.Add("date", time.Now().UTC().Format(http.TimeFormat))
	req.Header.Add("host", inboxhostname)

	keyID := "https://" + settings.Hostname + "/relay"

	err = signer.SignRequest(privateKey, keyID, req, jsonBytes)
	if err != nil {
		log.Fatal(err.Error())
	}
	req.Header["Signature"][0] = strings.Replace(req.Header["Signature"][0], "algorithm=\"hs2019\"", "algorithm=\"rsa-sha256\"", 1)

	customTransport := http.DefaultTransport.(*http.Transport).Clone()
	customTransport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
	client := &http.Client{Timeout: 10 * time.Second, Transport: customTransport}

	//	client := &http.Client{Timeout: 10 * time.Second}
	res, err := client.Do(req)
	if err != nil {
		log.Fatal(err)
	}

	defer res.Body.Close()
}