add vendoring

vendor/maunium.net/go/mautrix/crypto/olm/pk.go

@@ -0,0 +1,111 @@
+package olm
+
+// #cgo LDFLAGS: -lolm -lstdc++
+// #include <olm/olm.h>
+// #include <olm/pk.h>
+import "C"
+
+import (
+	"crypto/rand"
+	"encoding/json"
+	"unsafe"
+
+	"github.com/tidwall/sjson"
+
+	"maunium.net/go/mautrix/crypto/canonicaljson"
+	"maunium.net/go/mautrix/id"
+)
+
+// PkSigning stores a key pair for signing messages.
+type PkSigning struct {
+	int       *C.OlmPkSigning
+	mem       []byte
+	PublicKey id.Ed25519
+	Seed      []byte
+}
+
+func pkSigningSize() uint {
+	return uint(C.olm_pk_signing_size())
+}
+
+func pkSigningSeedLength() uint {
+	return uint(C.olm_pk_signing_seed_length())
+}
+
+func pkSigningPublicKeyLength() uint {
+	return uint(C.olm_pk_signing_public_key_length())
+}
+
+func pkSigningSignatureLength() uint {
+	return uint(C.olm_pk_signature_length())
+}
+
+func NewBlankPkSigning() *PkSigning {
+	memory := make([]byte, pkSigningSize())
+	return &PkSigning{
+		int: C.olm_pk_signing(unsafe.Pointer(&memory[0])),
+		mem: memory,
+	}
+}
+
+// Clear clears the underlying memory of a PkSigning object.
+func (p *PkSigning) Clear() {
+	C.olm_clear_pk_signing((*C.OlmPkSigning)(p.int))
+}
+
+// NewPkSigningFromSeed creates a new PkSigning object using the given seed.
+func NewPkSigningFromSeed(seed []byte) (*PkSigning, error) {
+	p := NewBlankPkSigning()
+	p.Clear()
+	pubKey := make([]byte, pkSigningPublicKeyLength())
+	if C.olm_pk_signing_key_from_seed((*C.OlmPkSigning)(p.int),
+		unsafe.Pointer(&pubKey[0]), C.size_t(len(pubKey)),
+		unsafe.Pointer(&seed[0]), C.size_t(len(seed))) == errorVal() {
+		return nil, p.lastError()
+	}
+	p.PublicKey = id.Ed25519(pubKey)
+	p.Seed = seed
+	return p, nil
+}
+
+// NewPkSigning creates a new PkSigning object, containing a key pair for signing messages.
+func NewPkSigning() (*PkSigning, error) {
+	// Generate the seed
+	seed := make([]byte, pkSigningSeedLength())
+	_, err := rand.Read(seed)
+	if err != nil {
+		panic(NotEnoughGoRandom)
+	}
+	pk, err := NewPkSigningFromSeed(seed)
+	return pk, err
+}
+
+// Sign creates a signature for the given message using this key.
+func (p *PkSigning) Sign(message []byte) ([]byte, error) {
+	signature := make([]byte, pkSigningSignatureLength())
+	if C.olm_pk_sign((*C.OlmPkSigning)(p.int), (*C.uint8_t)(unsafe.Pointer(&message[0])), C.size_t(len(message)),
+		(*C.uint8_t)(unsafe.Pointer(&signature[0])), C.size_t(len(signature))) == errorVal() {
+		return nil, p.lastError()
+	}
+	return signature, nil
+}
+
+// SignJSON creates a signature for the given object after encoding it to canonical JSON.
+func (p *PkSigning) SignJSON(obj interface{}) (string, error) {
+	objJSON, err := json.Marshal(obj)
+	if err != nil {
+		return "", err
+	}
+	objJSON, _ = sjson.DeleteBytes(objJSON, "unsigned")
+	objJSON, _ = sjson.DeleteBytes(objJSON, "signatures")
+	signature, err := p.Sign(canonicaljson.CanonicalJSONAssumeValid(objJSON))
+	if err != nil {
+		return "", err
+	}
+	return string(signature), nil
+}
+
+// lastError returns the last error that happened in relation to this PkSigning object.
+func (p *PkSigning) lastError() error {
+	return convertError(C.GoString(C.olm_pk_signing_last_error((*C.OlmPkSigning)(p.int))))
+}