matrix-go-test/vendor/maunium.net/go/mautrix/crypto/olm/pk.go
2023-02-08 18:23:21 +01:00

111 lines
3 KiB
Go

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))))
}