add vendoring

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

@@ -0,0 +1,143 @@
+//go:build !nosas
+// +build !nosas
+
+package olm
+
+// #cgo LDFLAGS: -lolm -lstdc++
+// #include <olm/olm.h>
+// #include <olm/sas.h>
+import "C"
+
+import (
+	"crypto/rand"
+	"unsafe"
+)
+
+// SAS stores an Olm Short Authentication String (SAS) object.
+type SAS struct {
+	int *C.OlmSAS
+	mem []byte
+}
+
+// NewBlankSAS initializes an empty SAS object.
+func NewBlankSAS() *SAS {
+	memory := make([]byte, sasSize())
+	return &SAS{
+		int: C.olm_sas(unsafe.Pointer(&memory[0])),
+		mem: memory,
+	}
+}
+
+// sasSize is the size of a SAS object in bytes.
+func sasSize() uint {
+	return uint(C.olm_sas_size())
+}
+
+// sasRandomLength is the number of random bytes needed to create an SAS object.
+func (sas *SAS) sasRandomLength() uint {
+	return uint(C.olm_create_sas_random_length(sas.int))
+}
+
+// NewSAS creates a new SAS object.
+func NewSAS() *SAS {
+	sas := NewBlankSAS()
+	random := make([]byte, sas.sasRandomLength()+1)
+	_, err := rand.Read(random)
+	if err != nil {
+		panic(NotEnoughGoRandom)
+	}
+	r := C.olm_create_sas(
+		(*C.OlmSAS)(sas.int),
+		unsafe.Pointer(&random[0]),
+		C.size_t(len(random)))
+	if r == errorVal() {
+		panic(sas.lastError())
+	} else {
+		return sas
+	}
+}
+
+// clear clears the memory used to back an SAS object.
+func (sas *SAS) clear() uint {
+	return uint(C.olm_clear_sas(sas.int))
+}
+
+// lastError returns the most recent error to happen to an SAS object.
+func (sas *SAS) lastError() error {
+	return convertError(C.GoString(C.olm_sas_last_error(sas.int)))
+}
+
+// pubkeyLength is the size of a public key in bytes.
+func (sas *SAS) pubkeyLength() uint {
+	return uint(C.olm_sas_pubkey_length((*C.OlmSAS)(sas.int)))
+}
+
+// GetPubkey gets the public key for the SAS object.
+func (sas *SAS) GetPubkey() []byte {
+	pubkey := make([]byte, sas.pubkeyLength())
+	r := C.olm_sas_get_pubkey(
+		(*C.OlmSAS)(sas.int),
+		unsafe.Pointer(&pubkey[0]),
+		C.size_t(len(pubkey)))
+	if r == errorVal() {
+		panic(sas.lastError())
+	}
+	return pubkey
+}
+
+// SetTheirKey sets the public key of the other user.
+func (sas *SAS) SetTheirKey(theirKey []byte) error {
+	theirKeyCopy := make([]byte, len(theirKey))
+	copy(theirKeyCopy, theirKey)
+	r := C.olm_sas_set_their_key(
+		(*C.OlmSAS)(sas.int),
+		unsafe.Pointer(&theirKeyCopy[0]),
+		C.size_t(len(theirKeyCopy)))
+	if r == errorVal() {
+		return sas.lastError()
+	}
+	return nil
+}
+
+// GenerateBytes generates bytes to use for the short authentication string.
+func (sas *SAS) GenerateBytes(info []byte, count uint) ([]byte, error) {
+	infoCopy := make([]byte, len(info))
+	copy(infoCopy, info)
+	output := make([]byte, count)
+	r := C.olm_sas_generate_bytes(
+		(*C.OlmSAS)(sas.int),
+		unsafe.Pointer(&infoCopy[0]),
+		C.size_t(len(infoCopy)),
+		unsafe.Pointer(&output[0]),
+		C.size_t(len(output)))
+	if r == errorVal() {
+		return nil, sas.lastError()
+	}
+	return output, nil
+}
+
+// macLength is the size of a message authentication code generated by olm_sas_calculate_mac.
+func (sas *SAS) macLength() uint {
+	return uint(C.olm_sas_mac_length((*C.OlmSAS)(sas.int)))
+}
+
+// CalculateMAC generates a message authentication code (MAC) based on the shared secret.
+func (sas *SAS) CalculateMAC(input []byte, info []byte) ([]byte, error) {
+	inputCopy := make([]byte, len(input))
+	copy(inputCopy, input)
+	infoCopy := make([]byte, len(info))
+	copy(infoCopy, info)
+	mac := make([]byte, sas.macLength())
+	r := C.olm_sas_calculate_mac(
+		(*C.OlmSAS)(sas.int),
+		unsafe.Pointer(&inputCopy[0]),
+		C.size_t(len(inputCopy)),
+		unsafe.Pointer(&infoCopy[0]),
+		C.size_t(len(infoCopy)),
+		unsafe.Pointer(&mac[0]),
+		C.size_t(len(mac)))
+	if r == errorVal() {
+		return nil, sas.lastError()
+	}
+	return mac, nil
+}