feat: downgrade to HTTPSignature draft-11 for Misskey<12.111.0.

deliver/sender.go

@@ -9,9 +9,17 @@ import (
 	"github.com/go-fed/httpsig"
 	"github.com/sirupsen/logrus"
 	"net/http"
+	"regexp"
 	"time"
 )
 
+func compatibilityForHTTPSignature11(request *http.Request, algorithm httpsig.Algorithm) {
+	signature := request.Header.Get("Signature")
+	regexp := regexp.MustCompile("algorithm=\"hs2019\"")
+	signature = regexp.ReplaceAllString(signature, string("algorithm=\""+algorithm+"\""))
+	request.Header.Set("Signature", signature)
+}
+
 func appendSignature(request *http.Request, body *[]byte, KeyID string, privateKey *rsa.PrivateKey) error {
 	request.Header.Set("Host", request.Host)
 
@@ -23,6 +31,7 @@ func appendSignature(request *http.Request, body *[]byte, KeyID string, privateK
 	if err != nil {
 		return err
 	}
+	compatibilityForHTTPSignature11(request, httpsig.RSA_SHA256) // Compatibility for Misskey <12.111.0
 	return nil
 }
 

deliver/sender_test.go

@@ -12,6 +12,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"os"
+	"regexp"
 	"testing"
 	"time"
 )
@@ -35,6 +36,13 @@ func TestAppendSignature(t *testing.T) {
 	req.Header.Set("Date", httpdate.Time2Str(time.Now()))
 	appendSignature(req, &body, "https://innocent.yukimochi.io/users/YUKIMOCHI#main-key", globalConfig.ActorKey())
 
+	// Activated compatibilityForHTTPSignature11
+	sign := req.Header.Get("Signature")
+	activated := regexp.MustCompile(string("algorithm=\"" + httpsig.RSA_SHA256 + "\"")).MatchString(sign)
+	if !activated {
+		t.Fatalf("Failed - " + "compatibilityForHTTPSignature11 is not activated")
+	}
+
 	// Verify HTTPSignature
 	verifier, err := httpsig.NewVerifier(req)
 	if err != nil {