121 lines
2.9 KiB
Go
121 lines
2.9 KiB
Go
package crypto
|
|
|
|
import (
|
|
"bytes"
|
|
"io"
|
|
"io/ioutil"
|
|
"mime"
|
|
"net/textproto"
|
|
|
|
"github.com/ProtonMail/go-mime"
|
|
|
|
"golang.org/x/crypto/openpgp"
|
|
"golang.org/x/crypto/openpgp/packet"
|
|
)
|
|
|
|
// SignatureCollector structure
|
|
type SignatureCollector struct {
|
|
config *packet.Config
|
|
keyring openpgp.KeyRing
|
|
target pmmime.VisitAcceptor
|
|
signature string
|
|
verified int
|
|
}
|
|
|
|
func newSignatureCollector(
|
|
targetAcceptor pmmime.VisitAcceptor, keyring openpgp.KeyRing, config *packet.Config,
|
|
) *SignatureCollector {
|
|
return &SignatureCollector{
|
|
target: targetAcceptor,
|
|
config: config,
|
|
keyring: keyring,
|
|
}
|
|
}
|
|
|
|
// Accept collects the signature
|
|
func (sc *SignatureCollector) Accept(
|
|
part io.Reader, header textproto.MIMEHeader,
|
|
hasPlainSibling, isFirst, isLast bool,
|
|
) (err error) {
|
|
parentMediaType, params, _ := mime.ParseMediaType(header.Get("Content-Type"))
|
|
if parentMediaType == "multipart/signed" {
|
|
newPart, rawBody := pmmime.GetRawMimePart(part, "--"+params["boundary"])
|
|
var multiparts []io.Reader
|
|
var multipartHeaders []textproto.MIMEHeader
|
|
if multiparts, multipartHeaders, err = pmmime.GetMultipartParts(newPart, params); err == nil {
|
|
hasPlainChild := false
|
|
for _, header := range multipartHeaders {
|
|
mediaType, _, _ := mime.ParseMediaType(header.Get("Content-Type"))
|
|
if mediaType == "text/plain" {
|
|
hasPlainChild = true
|
|
}
|
|
}
|
|
if len(multiparts) != 2 {
|
|
sc.verified = notSigned
|
|
// Invalid multipart/signed format just pass along
|
|
_, err = ioutil.ReadAll(rawBody)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
for i, p := range multiparts {
|
|
if err = sc.target.Accept(p, multipartHeaders[i], hasPlainChild, true, true); err != nil {
|
|
return
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
// actual multipart/signed format
|
|
err = sc.target.Accept(multiparts[0], multipartHeaders[0], hasPlainChild, true, true)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
partData, err := ioutil.ReadAll(multiparts[1])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
decodedPart := pmmime.DecodeContentEncoding(
|
|
bytes.NewReader(partData),
|
|
multipartHeaders[1].Get("Content-Transfer-Encoding"))
|
|
|
|
buffer, err := ioutil.ReadAll(decodedPart)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
buffer, err = pmmime.DecodeCharset(buffer, params)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
sc.signature = string(buffer)
|
|
str, _ := ioutil.ReadAll(rawBody)
|
|
rawBody = bytes.NewReader(str)
|
|
if sc.keyring != nil {
|
|
_, err = openpgp.CheckArmoredDetachedSignature(sc.keyring, rawBody, bytes.NewReader(buffer), sc.config)
|
|
|
|
if err != nil {
|
|
sc.verified = failed
|
|
} else {
|
|
sc.verified = ok
|
|
}
|
|
} else {
|
|
sc.verified = noVerifier
|
|
}
|
|
return nil
|
|
}
|
|
return
|
|
}
|
|
err = sc.target.Accept(part, header, hasPlainSibling, isFirst, isLast)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// GetSignature collected by Accept
|
|
func (sc SignatureCollector) GetSignature() string {
|
|
return sc.signature
|
|
}
|