refactor!: working WD-4 user discovery

pkg/lysand/actor_user.go

@@ -1,15 +1,7 @@
 package lysand
 
 import (
-	"bytes"
-	"context"
-	"crypto/ed25519"
-	"crypto/rand"
-	"encoding/base64"
 	"encoding/json"
-	"fmt"
-	"net/http"
-	"net/url"
 )
 
 // User represents a user object in the Lysand protocol. For more information, see the [Spec].
@@ -20,7 +12,7 @@ type User struct {
 
 	// PublicKey is the public key of the user.
 	// https://lysand.org/objects/user#public-key
-	PublicKey PublicKey `json:"public_key"`
+	PublicKey UserPublicKey `json:"public_key"`
 
 	// DisplayName is the display name of the user.
 	// https://lysand.org/objects/user#display-name
@@ -66,14 +58,6 @@ type User struct {
 	// https://lysand.org/objects/user#following
 	Following *URL `json:"following"`
 
-	// Likes is the likes of the user.
-	// https://lysand.org/objects/user#likes
-	Likes *URL `json:"likes"`
-
-	// Dislikes is the dislikes of the user.
-	// https://lysand.org/objects/user#dislikes
-	Dislikes *URL `json:"dislikes"`
-
 	// Inbox is the inbox of the user.
 	// https://lysand.org/objects/user#posts
 	Inbox *URL `json:"inbox"`
@@ -94,60 +78,3 @@ type Field struct {
 	Key   TextContentTypeMap `json:"key"`
 	Value TextContentTypeMap `json:"value"`
 }
-
-func (c *FederationClient) GetUser(ctx context.Context, uri *url.URL) (*User, error) {
-	resp, body, err := c.rawGET(ctx, uri)
-	if err != nil {
-		return nil, err
-	}
-
-	user := &User{}
-	if err := json.Unmarshal(body, user); err != nil {
-		return nil, err
-	}
-
-	fedHeaders, err := ExtractFederationHeaders(resp.Header)
-	if err != nil {
-		return nil, err
-	}
-
-	v := Verifier{ed25519.PublicKey(user.PublicKey.PublicKey)}
-	if !v.Verify("GET", uri, body, fedHeaders) {
-		c.log.V(2).Info("signature verification failed", "user", user.URI.String())
-		return nil, fmt.Errorf("signature verification failed")
-	}
-	c.log.V(2).Info("signature verification succeeded", "user", user.URI.String())
-
-	return user, nil
-}
-
-func (c *FederationClient) SendToInbox(ctx context.Context, signer Signer, user *User, object any) ([]byte, error) {
-	uri := user.Inbox.ToStd()
-
-	body, err := json.Marshal(object)
-	if err != nil {
-		return nil, err
-	}
-
-	nonce := make([]byte, 32)
-	if _, err := rand.Read(nonce); err != nil {
-		return nil, err
-	}
-
-	sigData := NewSignatureData("POST", base64.StdEncoding.EncodeToString(nonce), uri, hashSHA256(body))
-	sig := signer.Sign(*sigData)
-
-	req, err := http.NewRequestWithContext(ctx, "POST", uri.String(), bytes.NewReader(body))
-	if err != nil {
-		return nil, err
-	}
-
-	sig.Inject(req.Header)
-
-	_, respBody, err := c.doReq(req)
-	if err != nil {
-		return nil, err
-	}
-
-	return respBody, nil
-}

pkg/lysand/crypto.go

@@ -1,42 +1,5 @@
 package lysand
 
-import (
-	"bytes"
-	"crypto/ed25519"
-	"crypto/sha256"
-	"io"
-	"net/http"
-)
-
-func (c *FederationClient) ValidateSignatureHeader(req *http.Request) (bool, error) {
-	fedHeaders, err := ExtractFederationHeaders(req.Header)
-	if err != nil {
-		return false, err
-	}
-
-	// TODO: Fetch user from database instead of using the URI
-	user, err := c.GetUser(req.Context(), fedHeaders.SignedBy)
-	if err != nil {
-		return false, err
-	}
-
-	body, err := copyBody(req)
-	if err != nil {
-		return false, err
-	}
-
-	v := Verifier{ed25519.PublicKey(user.PublicKey.PublicKey)}
-	valid := v.Verify(req.Method, req.URL, body, fedHeaders)
-
-	return valid, nil
-}
-
-func hashSHA256(data []byte) []byte {
-	h := sha256.New()
-	h.Write(data)
-	return h.Sum(nil)
-}
-
 func must[In any, Out any](fn func(In) (Out, error), v In) Out {
 	out, err := fn(v)
 	if err != nil {
@@ -45,17 +8,3 @@ func must[In any, Out any](fn func(In) (Out, error), v In) Out {
 
 	return out
 }
-
-func copyBody(req *http.Request) ([]byte, error) {
-	body, err := io.ReadAll(req.Body)
-	if err != nil {
-		return nil, err
-	}
-
-	if err := req.Body.Close(); err != nil {
-		return nil, err
-	}
-
-	req.Body = io.NopCloser(bytes.NewBuffer(body))
-	return body, nil
-}

pkg/lysand/crypto/keys.go

@@ -0,0 +1,23 @@
+package versiacrypto
+
+import (
+	"crypto/ed25519"
+	"fmt"
+)
+
+type UnknownPublicKeyTypeError struct {
+	Got string
+}
+
+func (i UnknownPublicKeyTypeError) Error() string {
+	return fmt.Sprintf("unknown public key type: \"%s\"", i.Got)
+}
+
+func ToTypedKey(algorithm string, raw []byte) (any, error) {
+	switch algorithm {
+	case "ed25519":
+		return ed25519.PublicKey(raw), nil
+	default:
+		return nil, UnknownPublicKeyTypeError{algorithm}
+	}
+}

pkg/lysand/crypto/sha256.go

@@ -0,0 +1,9 @@
+package versiacrypto
+
+import "crypto/sha256"
+
+func SHA256(data []byte) []byte {
+	h := sha256.New()
+	h.Write(data)
+	return h.Sum(nil)
+}

pkg/lysand/crypto/verify.go

@@ -0,0 +1,29 @@
+package versiacrypto
+
+import (
+	"crypto"
+	"crypto/ed25519"
+	"fmt"
+	"reflect"
+)
+
+type InvalidPublicKeyTypeError struct {
+	Got reflect.Type
+}
+
+func (i InvalidPublicKeyTypeError) Error() string {
+	return fmt.Sprintf("failed to convert public key of type \"%s\"", i.Got.String())
+}
+
+type Verify = func(data, signature []byte) bool
+
+func NewVerify(pubKey crypto.PublicKey) (Verify, error) {
+	switch pk := pubKey.(type) {
+	case ed25519.PublicKey:
+		return func(data, signature []byte) bool {
+			return ed25519.Verify(pk, data, signature)
+		}, nil
+	default:
+		return nil, InvalidPublicKeyTypeError{reflect.TypeOf(pk)}
+	}
+}

pkg/lysand/federation_client.go

@@ -1,10 +1,9 @@
 package lysand
 
 import (
-	"context"
 	"fmt"
 	"github.com/go-logr/logr"
-	"io"
+	"github.com/lysand-org/versia-go/pkg/protoretry"
 	"net/http"
 	"net/url"
 	"time"
@@ -22,6 +21,7 @@ func (e *ResponseError) Error() string {
 type FederationClient struct {
 	log   logr.Logger
 	httpC *http.Client
+	hc    *protoretry.Client
 }
 
 type Opt func(c *FederationClient)
@@ -53,49 +53,11 @@ func NewClient(opts ...Opt) *FederationClient {
 		useragent: "github.com/lysand-org/versia-go/pkg/lysand#0.0.1",
 	}
 
+	c.hc = protoretry.New(c.httpC)
+
 	return c
 }
 
-func (c *FederationClient) rawGET(ctx context.Context, uri *url.URL) (*http.Response, []byte, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", uri.String(), nil)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	return c.doReq(req)
-}
-
-func (c *FederationClient) rawPOST(ctx context.Context, uri *url.URL, body io.Reader) (*http.Response, []byte, error) {
-	req, err := http.NewRequestWithContext(ctx, "POST", uri.String(), body)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	return c.doReq(req)
-}
-
-func (c *FederationClient) doReq(req *http.Request) (*http.Response, []byte, error) {
-	resp, err := c.httpC.Do(req)
-	if err != nil {
-		return nil, nil, err
-	}
-	defer resp.Body.Close()
-
-	if resp.StatusCode >= http.StatusBadRequest {
-		return resp, nil, &ResponseError{
-			StatusCode: resp.StatusCode,
-			URL:        req.URL,
-		}
-	}
-
-	respBody, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return resp, nil, err
-	}
-
-	return resp, respBody, nil
-}
-
 type federationClientHTTPTransport struct {
 	inner     http.RoundTripper
 	useragent string

pkg/lysand/federation_headers.go

@@ -25,6 +25,14 @@ func (f *FederationHeaders) Inject(h http.Header) {
 	h.Set("x-signature", base64.StdEncoding.EncodeToString(f.Signature))
 }
 
+func (f *FederationHeaders) Headers() map[string]string {
+	return map[string]string{
+		"x-signed-by": f.SignedBy.String(),
+		"x-nonce":     f.Nonce,
+		"x-signature": base64.StdEncoding.EncodeToString(f.Signature),
+	}
+}
+
 func ExtractFederationHeaders(h http.Header) (*FederationHeaders, error) {
 	signedBy := h.Get("x-signed-by")
 	if signedBy == "" {
@@ -41,14 +49,19 @@ func ExtractFederationHeaders(h http.Header) (*FederationHeaders, error) {
 		return nil, fmt.Errorf("missing x-nonce header")
 	}
 
-	signature := h.Get("x-signature")
-	if signature == "" {
+	rawSignature := h.Get("x-signature")
+	if rawSignature == "" {
 		return nil, fmt.Errorf("missing x-signature header")
 	}
 
+	signature, err := base64.StdEncoding.DecodeString(rawSignature)
+	if err != nil {
+		return nil, err
+	}
+
 	return &FederationHeaders{
 		SignedBy:  u,
 		Nonce:     nonce,
-		Signature: []byte(signature),
+		Signature: signature,
 	}, nil
 }

pkg/lysand/instance_metadata.go

@@ -0,0 +1,111 @@
+package lysand
+
+import (
+	"encoding/json"
+)
+
+// InstanceMetadata represents the metadata of a Lysand instance. For more information, see the [Spec].
+//
+// ! Unlike other entities, instance metadata is not meant to be federated.
+//
+// [Spec]: https://versia.pub/entities/instance-metadata
+type InstanceMetadata struct {
+	// Type is always "InstanceMetadata"
+	Type string `json:"type"`
+
+	// Extensions is a map of active extensions
+	Extensions Extensions `json:"extensions,omitempty"`
+
+	// Name is the name of the instance
+	Name string `json:"name"`
+
+	// Description is a description of the instance
+	Description *string `json:"description,omitempty"`
+
+	// Host is the hostname of the instance, including the port
+	Host string `json:"host,omitempty"`
+
+	// PublicKey is the public key of the instance
+	PublicKey InstancePublicKey `json:"public_key"`
+
+	// SharedInbox is the URL to the instance's shared inbox
+	SharedInbox *URL `json:"shared_inbox,omitempty"`
+
+	// Moderators is a URL to a collection of moderators
+	Moderators *URL `json:"moderators,omitempty"`
+
+	// Admins is a URL to a collection of administrators
+	Admins *URL `json:"admins,omitempty"`
+
+	// Logo is the URL to the instance's logo
+	Logo *ImageContentTypeMap `json:"logo,omitempty"`
+
+	// Banner is the URL to the instance's banner
+	Banner *ImageContentTypeMap `json:"banner,omitempty"`
+
+	// Software is information about the instance software
+	Software InstanceSoftware `json:"software"`
+
+	// Compatibility is information about the instance's compatibility with different Lysand versions
+	Compatibility InstanceCompatibility `json:"compatibility"`
+}
+
+func (s InstanceMetadata) MarshalJSON() ([]byte, error) {
+	type instanceMetadata InstanceMetadata
+	s2 := instanceMetadata(s)
+	s2.Type = "InstanceMetadata"
+	return json.Marshal(s2)
+}
+
+// InstanceSoftware represents the software of a Lysand instance.
+type InstanceSoftware struct {
+	// Name is the name of the instance software
+	Name string `json:"name"`
+	// Version is the version of the instance software
+	Version string `json:"version"`
+}
+
+// InstanceCompatibility represents the compatibility of a Lysand instance.
+type InstanceCompatibility struct {
+	// Versions is a list of versions of Lysand the instance is compatible with
+	Versions []string `json:"versions"`
+
+	// Extensions is a list of extensions supported by the instance
+	Extensions []string `json:"extensions"`
+}
+
+// InstancePublicKey represents the public key of a Versia instance.
+type InstancePublicKey struct {
+	// Algorithm can only be `ed25519` for now
+	Algorithm string `json:"algorithm"`
+
+	Key    *SPKIPublicKey  `json:"-"`
+	RawKey json.RawMessage `json:"key"`
+}
+
+func (k *InstancePublicKey) UnmarshalJSON(raw []byte) error {
+	type t InstancePublicKey
+	k2 := (*t)(k)
+	if err := json.Unmarshal(raw, k2); err != nil {
+		return nil
+	}
+
+	var err error
+	if k2.Key, err = unmarshalSPKIPubKey(k2.Algorithm, k2.RawKey); err != nil {
+		return nil
+	}
+
+	return nil
+}
+
+func (k InstancePublicKey) MarshalJSON() ([]byte, error) {
+	type t InstancePublicKey
+	k2 := t(k)
+
+	var err error
+	if k2.RawKey, err = k2.Key.MarshalJSON(); err != nil {
+		return nil, err
+	}
+
+	return json.Marshal(k2)
+}

pkg/lysand/server_metadata.go

@@ -1,64 +0,0 @@
-package lysand
-
-import (
-	"encoding/json"
-
-	"github.com/Masterminds/semver"
-)
-
-// ServerMetadata represents the metadata of a Lysand server. For more information, see the [Spec].
-//
-// ! Unlike other objects, server metadata is not meant to be federated.
-//
-// [Spec]: https://lysand.org/objects/server-metadata
-type ServerMetadata struct {
-	// Type is always "ServerMetadata"
-	// https://lysand.org/objects/server-metadata#type
-	Type string `json:"type"`
-
-	// Extensions is a map of active extensions
-	// https://lysand.org/objects/server-metadata#extensions
-	Extensions Extensions `json:"extensions,omitempty"`
-
-	// Name is the name of the server
-	// https://lysand.org/objects/server-metadata#name
-	Name string `json:"name"`
-
-	// Version is the version of the server software
-	// https://lysand.org/objects/server-metadata#version
-	Version *semver.Version `json:"version"`
-
-	// Description is a description of the server
-	// https://lysand.org/objects/server-metadata#description
-	Description *string `json:"description,omitempty"`
-
-	// Website is the URL to the server's website
-	// https://lysand.org/objects/server-metadata#website
-	Website *URL `json:"website,omitempty"`
-
-	// Moderators is a list of URLs to moderators
-	// https://lysand.org/objects/server-metadata#moderators
-	Moderators []*URL `json:"moderators,omitempty"`
-
-	// Admins is a list of URLs to administrators
-	// https://lysand.org/objects/server-metadata#admins
-	Admins []*URL `json:"admins,omitempty"`
-
-	// Logo is the URL to the server's logo
-	// https://lysand.org/objects/server-metadata#logo
-	Logo *ImageContentTypeMap `json:"logo,omitempty"`
-
-	// Banner is the URL to the server's banner
-	// https://lysand.org/objects/server-metadata#banner
-	Banner *ImageContentTypeMap `json:"banner,omitempty"`
-
-	// SupportedExtensions is a list of supported extensions
-	SupportedExtensions []string `json:"supported_extensions"`
-}
-
-func (s ServerMetadata) MarshalJSON() ([]byte, error) {
-	type serverMetadata ServerMetadata
-	s2 := serverMetadata(s)
-	s2.Type = "ServerMetadata"
-	return json.Marshal(s2)
-}

pkg/lysand/signature_data.go

@@ -1,10 +1,13 @@
 package lysand
 
 import (
+	"crypto"
 	"crypto/ed25519"
 	"encoding/base64"
 	"fmt"
+	versiacrypto "github.com/lysand-org/versia-go/pkg/lysand/crypto"
 	"net/url"
+	"os"
 	"strings"
 )
 
@@ -32,8 +35,16 @@ func (s *SignatureData) String() string {
 	return fmt.Sprintf("%s %s?%s %s %s", strings.ToLower(s.RequestMethod), s.URL.Path, s.URL.RawQuery, s.Nonce, base64.StdEncoding.EncodeToString(s.Digest))
 }
 
-func (s *SignatureData) Validate(pubKey ed25519.PublicKey, signature []byte) bool {
-	return ed25519.Verify(pubKey, []byte(s.String()), signature)
+func (s *SignatureData) Validate(pubKey crypto.PublicKey, signature []byte) bool {
+	data := []byte(s.String())
+
+	verify, err := versiacrypto.NewVerify(pubKey)
+	if err != nil {
+		_, _ = fmt.Fprintf(os.Stderr, "%v\n", err)
+		return false
+	}
+
+	return verify(data, signature)
 }
 
 func (s *SignatureData) Sign(privKey ed25519.PrivateKey) []byte {
@@ -54,11 +65,10 @@ func (s Signer) Sign(signatureData SignatureData) *FederationHeaders {
 }
 
 type Verifier struct {
-	PublicKey ed25519.PublicKey
+	PublicKey crypto.PublicKey
 }
 
 func (v Verifier) Verify(method string, u *url.URL, body []byte, fedHeaders *FederationHeaders) bool {
-	sigData := NewSignatureData(method, fedHeaders.Nonce, u, hashSHA256(body))
-
-	return sigData.Validate(v.PublicKey, fedHeaders.Signature)
+	return NewSignatureData(method, fedHeaders.Nonce, u, versiacrypto.SHA256(body)).
+		Validate(v.PublicKey, fedHeaders.Signature)
 }

pkg/lysand/spki_public_key.go

@@ -1,59 +1,92 @@
 package lysand
 
 import (
-	"crypto/ed25519"
+	"crypto"
 	"crypto/x509"
 	"encoding/base64"
 	"encoding/json"
-	"errors"
 )
 
-var (
-	ErrInvalidPublicKeyType = errors.New("invalid public key type")
-)
-
-// PublicKey represents a public key for a user. For more information, see the [Spec].
+// UserPublicKey represents a public key for a user. For more information, see the [Spec].
 //
 // [Spec]: https://lysand.org/security/keys#public-key-cryptography
-type PublicKey struct {
-	PublicKey SPKIPublicKey `json:"public_key"`
-	Actor     *URL          `json:"actor"`
+type UserPublicKey struct {
+	Actor *URL `json:"actor"`
+
+	// Algorithm can only be `ed25519` for now
+	Algorithm string `json:"algorithm"`
+
+	Key    *SPKIPublicKey  `json:"-"`
+	RawKey json.RawMessage `json:"key"`
 }
 
-// SPKIPublicKey is a type that represents a [ed25519.PublicKey] in the SPKI
-// format.
-type SPKIPublicKey ed25519.PublicKey
+func (k *UserPublicKey) UnmarshalJSON(raw []byte) error {
+	type t UserPublicKey
+	k2 := (*t)(k)
 
-// UnmarshalJSON decodes the public key from a base64 encoded string and then unmarshals it from the SPKI form.
-func (k *SPKIPublicKey) UnmarshalJSON(raw []byte) error {
-	rawStr := ""
-	if err := json.Unmarshal(raw, &rawStr); err != nil {
+	if err := json.Unmarshal(raw, k2); err != nil {
 		return err
 	}
 
-	raw, err := base64.StdEncoding.DecodeString(rawStr)
-	if err != nil {
+	var err error
+	if k2.Key, err = unmarshalSPKIPubKey(k2.Algorithm, k2.RawKey); err != nil {
 		return err
 	}
 
-	parsed, err := x509.ParsePKIXPublicKey(raw)
-	if err != nil {
-		return err
-	}
-
-	edKey, ok := parsed.(ed25519.PublicKey)
-	if !ok {
-		return ErrInvalidPublicKeyType
-	}
-
-	*k = SPKIPublicKey(edKey)
+	*k = UserPublicKey(*k2)
 
 	return nil
 }
 
+func (k UserPublicKey) MarshalJSON() ([]byte, error) {
+	type t UserPublicKey
+	k2 := t(k)
+
+	var err error
+	if k2.RawKey, err = k2.Key.MarshalJSON(); err != nil {
+		return nil, err
+	}
+
+	return json.Marshal(k2)
+}
+
+// SPKIPublicKey is a type that represents a [ed25519.PublicKey] in the SPKI
+// format.
+type SPKIPublicKey struct {
+	Key       any
+	Algorithm string
+}
+
+func unmarshalSPKIPubKey(algorithm string, raw []byte) (*SPKIPublicKey, error) {
+	rawStr := ""
+	if err := json.Unmarshal(raw, &rawStr); err != nil {
+		return nil, err
+	}
+
+	raw, err := base64.StdEncoding.DecodeString(rawStr)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewSPKIPubKey(algorithm, raw)
+}
+
+// NewSPKIPubKey decodes the public key from a base64 encoded string and then unmarshals it from the SPKI form.
+func NewSPKIPubKey(algorithm string, raw []byte) (*SPKIPublicKey, error) {
+	parsed, err := x509.ParsePKIXPublicKey(raw)
+	if err != nil {
+		return nil, err
+	}
+
+	return &SPKIPublicKey{
+		Key:       parsed,
+		Algorithm: algorithm,
+	}, nil
+}
+
 // MarshalJSON marshals the SPKI-encoded public key to a base64 encoded string.
 func (k SPKIPublicKey) MarshalJSON() ([]byte, error) {
-	raw, err := x509.MarshalPKIXPublicKey(ed25519.PublicKey(k))
+	raw, err := x509.MarshalPKIXPublicKey(k.Key)
 	if err != nil {
 		return nil, err
 	}
@@ -61,6 +94,6 @@ func (k SPKIPublicKey) MarshalJSON() ([]byte, error) {
 	return json.Marshal(base64.StdEncoding.EncodeToString(raw))
 }
 
-func (k SPKIPublicKey) ToStd() ed25519.PublicKey {
-	return ed25519.PublicKey(k)
+func (k SPKIPublicKey) ToKey() crypto.PublicKey {
+	return k.Key
 }

pkg/lysand/spki_public_key_test.go

@@ -12,20 +12,20 @@ import (
 func TestSPKIPublicKey_UnmarshalJSON(t *testing.T) {
 	expectedPk := must(x509.ParsePKIXPublicKey, must(base64.StdEncoding.DecodeString, "MCowBQYDK2VwAyEAgKNt+9eyOXdb7MSrrmHlsFD2H9NGwC+56PjpWD46Tcs="))
 
-	pk := PublicKey{}
+	pk := UserPublicKey{}
 	raw := []byte(`{"public_key":"MCowBQYDK2VwAyEAgKNt+9eyOXdb7MSrrmHlsFD2H9NGwC+56PjpWD46Tcs="}`)
 	if err := json.Unmarshal(raw, &pk); err != nil {
 		t.Error(err)
 	}
 
-	assert.Equal(t, expectedPk, ed25519.PublicKey(pk.PublicKey))
+	assert.Equal(t, expectedPk, ed25519.PublicKey(pk.Key))
 }
 
 func TestSPKIPublicKey_MarshalJSON(t *testing.T) {
 	expectedPk := must(x509.ParsePKIXPublicKey, must(base64.StdEncoding.DecodeString, "MCowBQYDK2VwAyEAgKNt+9eyOXdb7MSrrmHlsFD2H9NGwC+56PjpWD46Tcs=")).(ed25519.PublicKey)
 
-	pk := PublicKey{
-		PublicKey: SPKIPublicKey(expectedPk),
+	pk := UserPublicKey{
+		Key: SPKIPublicKey(expectedPk),
 	}
 	if _, err := json.Marshal(pk); err != nil {
 		t.Error(err)