forgejo/modules/activitypub/client.go
2023-09-15 06:13:19 +00:00

125 lines
3.4 KiB
Go

// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package activitypub
import (
"bytes"
"context"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"fmt"
"net/http"
"strings"
"time"
user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/proxy"
"code.gitea.io/gitea/modules/setting"
"github.com/go-fed/httpsig"
)
const (
// ActivityStreamsContentType const
ActivityStreamsContentType = `application/ld+json; profile="https://www.w3.org/ns/activitystreams"`
httpsigExpirationTime = 60
)
// Gets the current time as an RFC 2616 formatted string
// RFC 2616 requires RFC 1123 dates but with GMT instead of UTC
func CurrentTime() string {
return strings.ReplaceAll(time.Now().UTC().Format(time.RFC1123), "UTC", "GMT")
}
func containsRequiredHTTPHeaders(method string, headers []string) error {
var hasRequestTarget, hasDate, hasDigest bool
for _, header := range headers {
hasRequestTarget = hasRequestTarget || header == httpsig.RequestTarget
hasDate = hasDate || header == "Date"
hasDigest = hasDigest || header == "Digest"
}
if !hasRequestTarget {
return fmt.Errorf("missing http header for %s: %s", method, httpsig.RequestTarget)
} else if !hasDate {
return fmt.Errorf("missing http header for %s: Date", method)
} else if !hasDigest && method != http.MethodGet {
return fmt.Errorf("missing http header for %s: Digest", method)
}
return nil
}
// Client struct
type Client struct {
client *http.Client
algs []httpsig.Algorithm
digestAlg httpsig.DigestAlgorithm
getHeaders []string
postHeaders []string
priv *rsa.PrivateKey
pubID string
}
// NewClient function
func NewClient(ctx context.Context, user *user_model.User, pubID string) (c *Client, err error) {
if err = containsRequiredHTTPHeaders(http.MethodGet, setting.Federation.GetHeaders); err != nil {
return nil, err
} else if err = containsRequiredHTTPHeaders(http.MethodPost, setting.Federation.PostHeaders); err != nil {
return nil, err
}
priv, err := GetPrivateKey(ctx, user)
if err != nil {
return nil, err
}
privPem, _ := pem.Decode([]byte(priv))
privParsed, err := x509.ParsePKCS1PrivateKey(privPem.Bytes)
if err != nil {
return nil, err
}
c = &Client{
client: &http.Client{
Transport: &http.Transport{
Proxy: proxy.Proxy(),
},
},
algs: setting.HttpsigAlgs,
digestAlg: httpsig.DigestAlgorithm(setting.Federation.DigestAlgorithm),
getHeaders: setting.Federation.GetHeaders,
postHeaders: setting.Federation.PostHeaders,
priv: privParsed,
pubID: pubID,
}
return c, err
}
// NewRequest function
func (c *Client) NewRequest(b []byte, to string) (req *http.Request, err error) {
buf := bytes.NewBuffer(b)
req, err = http.NewRequest(http.MethodPost, to, buf)
if err != nil {
return nil, err
}
req.Header.Add("Content-Type", ActivityStreamsContentType)
req.Header.Add("Date", CurrentTime())
req.Header.Add("User-Agent", "Gitea/"+setting.AppVer)
signer, _, err := httpsig.NewSigner(c.algs, c.digestAlg, c.postHeaders, httpsig.Signature, httpsigExpirationTime)
if err != nil {
return nil, err
}
err = signer.SignRequest(c.priv, c.pubID, req, b)
return req, err
}
// Post function
func (c *Client) Post(b []byte, to string) (resp *http.Response, err error) {
var req *http.Request
if req, err = c.NewRequest(b, to); err != nil {
return nil, err
}
resp, err = c.client.Do(req)
return resp, err
}