Merge pull request #18 from MetaMask/didweb

verifiers: add support for did:web
This commit is contained in:
Michael Muré
2025-08-05 16:26:06 +02:00
committed by GitHub
3 changed files with 284 additions and 0 deletions

View File

@@ -124,6 +124,7 @@ func main() {
| Method | Controller | Verifier | Description |
|-----------|------------|----------|----------------------------------------------------|
| `did:key` | ✅ | ✅ | Self-contained DIDs based on public keys |
| `did:web` | ❌ | ✅ | DID document resolved with HTTP |
| `did:plc` | ❌ | ✅ | Bluesky's DID with rotation and a public directory |
### Supported Verification Method Types

155
verifiers/did-web/web.go Normal file
View File

@@ -0,0 +1,155 @@
package did_web
import (
"fmt"
"io"
"net"
"net/http"
"net/url"
"regexp"
"strconv"
"strings"
"github.com/MetaMask/go-did-it"
"github.com/MetaMask/go-did-it/document"
)
// Specification: https://w3c-ccg.github.io/did-method-web/
func init() {
did.RegisterMethod("web", Decode)
}
var _ did.DID = DidWeb{}
type DidWeb struct {
msi string // method-specific identifier, i.e. "12345" in "did:web:12345"
parts []string
}
func Decode(identifier string) (did.DID, error) {
const webPrefix = "did:web:"
if !strings.HasPrefix(identifier, webPrefix) {
return nil, fmt.Errorf("%w: must start with 'did:web'", did.ErrInvalidDid)
}
msi := identifier[len(webPrefix):]
if len(msi) == 0 {
return nil, fmt.Errorf("%w: empty did:web identifier", did.ErrInvalidDid)
}
parts := strings.Split(msi, ":")
host, err := url.PathUnescape(parts[0])
if err != nil {
return nil, fmt.Errorf("%w: %w", did.ErrInvalidDid, err)
}
if !isValidHost(host) {
return nil, fmt.Errorf("%w: invalid host", did.ErrInvalidDid)
}
parts[0] = host
for i := 1; i < len(parts); i++ {
parts[i], err = url.PathUnescape(parts[i])
if err != nil {
return nil, fmt.Errorf("%w: %w", did.ErrInvalidDid, err)
}
}
return DidWeb{msi: msi, parts: parts}, nil
}
func (d DidWeb) Method() string {
return "web"
}
func (d DidWeb) Document(opts ...did.ResolutionOption) (did.Document, error) {
params := did.CollectResolutionOpts(opts)
var u string
var err error
if len(d.parts) == 1 {
u, err = url.JoinPath("https://"+d.parts[0], ".well-known/did.json")
} else {
parts := append(d.parts[1:], "did.json")
u, err = url.JoinPath("https://"+d.parts[0], parts...)
}
if err != nil {
return nil, fmt.Errorf("%w: %w", did.ErrResolutionFailure, err)
}
req, err := http.NewRequestWithContext(params.Context(), "GET", u, nil)
if err != nil {
return nil, fmt.Errorf("%w: %w", did.ErrResolutionFailure, err)
}
req.Header.Set("User-Agent", "go-did-it")
res, err := params.HttpClient().Do(req)
if err != nil {
return nil, fmt.Errorf("%w: %w", did.ErrResolutionFailure, err)
}
defer res.Body.Close()
if res.StatusCode != http.StatusOK {
return nil, fmt.Errorf("%w: HTTP %d", did.ErrResolutionFailure, res.StatusCode)
}
// limit at 1MB to avoid abuse
limiter := io.LimitReader(res.Body, 1<<20)
doc, err := document.FromJsonReader(limiter)
if err != nil {
return nil, fmt.Errorf("%w: %w", did.ErrResolutionFailure, err)
}
if doc.ID() != d.String() {
return nil, fmt.Errorf("%w: did:web identifier mismatch", did.ErrResolutionFailure)
}
return doc, nil
}
func (d DidWeb) String() string {
return fmt.Sprintf("did:web:%s", d.msi)
}
func (d DidWeb) ResolutionIsExpensive() bool {
// requires an external HTTP request
return true
}
func (d DidWeb) Equal(d2 did.DID) bool {
if d2, ok := d2.(DidWeb); ok {
return d.msi == d2.msi
}
if d2, ok := d2.(*DidWeb); ok {
return d.msi == d2.msi
}
return false
}
var domainRegexp = regexp.MustCompile(`^(?i)[a-z0-9]([a-z0-9-]*[a-z0-9])?(\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)+\.?$`)
func isValidHost(host string) bool {
h, port, err := net.SplitHostPort(host)
if err == nil {
portInt, err := strconv.Atoi(port)
if err != nil {
return false
}
if portInt < 0 || portInt > 65535 {
return false
}
host = h
}
if !domainRegexp.MatchString(host) {
return false
}
if ip := net.ParseIP(host); ip != nil {
// disallow IP addresses
return false
}
return true
}

View File

@@ -0,0 +1,128 @@
package did_web
import (
"fmt"
"io"
"net/http"
"strings"
"testing"
"github.com/stretchr/testify/require"
"github.com/MetaMask/go-did-it"
)
func TestDecode(t *testing.T) {
testcases := []struct {
did string
valid bool
}{
{"did:web:w3c-ccg.github.io", true},
{"did:web:w3c-ccg.github.io:user:alice", true},
{"did:web:example.com%3A3000", true},
}
for _, tc := range testcases {
t.Run(tc.did, func(t *testing.T) {
_, err := Decode(tc.did)
if tc.valid && err != nil {
t.Errorf("Decode(%q) = %v, want nil", tc.did, err)
} else if !tc.valid && err == nil {
t.Errorf("Decode(%q) = nil, want error", tc.did)
}
})
}
}
func TestIsValidHost(t *testing.T) {
testcases := []struct {
host string
valid bool
}{
{"example.com", true},
{"sub.example.com", true},
{"example.com:8080", true},
{"w3c-ccg.github.io", true},
{"192.168.1.1", false},
{"invalid..com", false},
{".example.com", false},
{"example.com.", true},
{"", false},
{"just_invalid", false},
{"-example.com", false},
{"example.com-", false},
}
for _, tc := range testcases {
t.Run(tc.host, func(t *testing.T) {
if isValidHost(tc.host) != tc.valid {
t.Errorf("isValidHost(%q) = %v, want %v", tc.host, isValidHost(tc.host), tc.valid)
}
})
}
}
func TestResolution(t *testing.T) {
client := &MockHTTPClient{
url: "https://example.com/.well-known/did.json",
resp: `{
"@context": [
"https://www.w3.org/ns/did/v1",
"https://w3id.org/security/suites/ed25519-2020/v1",
"https://w3id.org/security/suites/x25519-2020/v1"
],
"id": "did:web:example.com",
"verificationMethod": [{
"id": "did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK#z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK",
"type": "Ed25519VerificationKey2020",
"controller": "did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK",
"publicKeyMultibase": "z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK"
}],
"authentication": [
"did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK#z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK"
],
"assertionMethod": [
"did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK#z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK"
],
"capabilityDelegation": [
"did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK#z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK"
],
"capabilityInvocation": [
"did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK#z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK"
],
"keyAgreement": [{
"id": "did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK#z6LSj72tK8brWgZja8NLRwPigth2T9QRiG1uH9oKZuKjdh9p",
"type": "X25519KeyAgreementKey2020",
"controller": "did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK",
"publicKeyMultibase": "z6LSj72tK8brWgZja8NLRwPigth2T9QRiG1uH9oKZuKjdh9p"
}]
}`,
}
d, err := Decode("did:web:example.com")
require.NoError(t, err)
doc, err := d.Document(did.WithHttpClient(client))
require.NoError(t, err)
require.Equal(t, "did:web:example.com", doc.ID())
require.Len(t, doc.VerificationMethods(), 1)
require.Len(t, doc.Authentication(), 1)
require.Len(t, doc.Assertion(), 1)
require.Len(t, doc.KeyAgreement(), 1)
}
type MockHTTPClient struct {
url string
resp string
}
func (m *MockHTTPClient) Do(req *http.Request) (*http.Response, error) {
if req.URL.String() != m.url {
return nil, fmt.Errorf("unexpected url: %s", req.URL.String())
}
return &http.Response{
StatusCode: http.StatusOK,
Body: io.NopCloser(strings.NewReader(m.resp)),
}, nil
}