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path: root/crypto/secp256k1/secp256.go
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Diffstat (limited to 'crypto/secp256k1/secp256.go')
-rw-r--r--crypto/secp256k1/secp256.go201
1 files changed, 43 insertions, 158 deletions
diff --git a/crypto/secp256k1/secp256.go b/crypto/secp256k1/secp256.go
index 2c5f61450..070e0d902 100644
--- a/crypto/secp256k1/secp256.go
+++ b/crypto/secp256k1/secp256.go
@@ -14,10 +14,9 @@
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+// Package secp256k1 wraps the bitcoin secp256k1 C library.
package secp256k1
-// TODO: set USE_SCALAR_4X64 depending on platform?
-
/*
#cgo CFLAGS: -I./libsecp256k1
#cgo CFLAGS: -I./libsecp256k1/src/
@@ -29,7 +28,7 @@ package secp256k1
#define NDEBUG
#include "./libsecp256k1/src/secp256k1.c"
#include "./libsecp256k1/src/modules/recovery/main_impl.h"
-#include "pubkey_scalar_mul.h"
+#include "ext.h"
typedef void (*callbackFunc) (const char* msg, void* data);
extern void secp256k1GoPanicIllegal(const char* msg, void* data);
@@ -45,16 +44,6 @@ import (
"github.com/ethereum/go-ethereum/crypto/randentropy"
)
-//#define USE_FIELD_5X64
-
-/*
- TODO:
- > store private keys in buffer and shuffle (deters persistence on swap disc)
- > byte permutation (changing)
- > xor with chaning random block (to deter scanning memory for 0x63) (stream cipher?)
-*/
-
-// holds ptr to secp256k1_context_struct (see secp256k1/include/secp256k1.h)
var (
context *C.secp256k1_context
N *big.Int
@@ -67,127 +56,57 @@ func init() {
HalfN, _ = new(big.Int).SetString("7fffffffffffffffffffffffffffffff5d576e7357a4501ddfe92f46681b20a0", 16)
// around 20 ms on a modern CPU.
- context = C.secp256k1_context_create(3) // SECP256K1_START_SIGN | SECP256K1_START_VERIFY
+ context = C.secp256k1_context_create_sign_verify()
C.secp256k1_context_set_illegal_callback(context, C.callbackFunc(C.secp256k1GoPanicIllegal), nil)
C.secp256k1_context_set_error_callback(context, C.callbackFunc(C.secp256k1GoPanicError), nil)
}
var (
- ErrInvalidMsgLen = errors.New("invalid message length for signature recovery")
+ ErrInvalidMsgLen = errors.New("invalid message length, need 32 bytes")
ErrInvalidSignatureLen = errors.New("invalid signature length")
ErrInvalidRecoveryID = errors.New("invalid signature recovery id")
+ ErrInvalidKey = errors.New("invalid private key")
+ ErrSignFailed = errors.New("signing failed")
+ ErrRecoverFailed = errors.New("recovery failed")
)
-func GenerateKeyPair() ([]byte, []byte) {
- var seckey []byte = randentropy.GetEntropyCSPRNG(32)
- var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0]))
- var pubkey64 []byte = make([]byte, 64) // secp256k1_pubkey
- var pubkey65 []byte = make([]byte, 65) // 65 byte uncompressed pubkey
- pubkey64_ptr := (*C.secp256k1_pubkey)(unsafe.Pointer(&pubkey64[0]))
- pubkey65_ptr := (*C.uchar)(unsafe.Pointer(&pubkey65[0]))
-
- ret := C.secp256k1_ec_pubkey_create(
- context,
- pubkey64_ptr,
- seckey_ptr,
- )
-
- if ret != C.int(1) {
- return GenerateKeyPair() // invalid secret, try again
- }
-
- var output_len C.size_t
-
- C.secp256k1_ec_pubkey_serialize( // always returns 1
- context,
- pubkey65_ptr,
- &output_len,
- pubkey64_ptr,
- 0, // SECP256K1_EC_COMPRESSED
- )
-
- return pubkey65, seckey
-}
-
-func GeneratePubKey(seckey []byte) ([]byte, error) {
- if err := VerifySeckeyValidity(seckey); err != nil {
- return nil, err
+// Sign creates a recoverable ECDSA signature.
+// The produced signature is in the 65-byte [R || S || V] format where V is 0 or 1.
+//
+// The caller is responsible for ensuring that msg cannot be chosen
+// directly by an attacker. It is usually preferable to use a cryptographic
+// hash function on any input before handing it to this function.
+func Sign(msg []byte, seckey []byte) ([]byte, error) {
+ if len(msg) != 32 {
+ return nil, ErrInvalidMsgLen
}
-
- var pubkey []byte = make([]byte, 64)
- var pubkey_ptr *C.secp256k1_pubkey = (*C.secp256k1_pubkey)(unsafe.Pointer(&pubkey[0]))
-
- var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0]))
-
- ret := C.secp256k1_ec_pubkey_create(
- context,
- pubkey_ptr,
- seckey_ptr,
- )
-
- if ret != C.int(1) {
- return nil, errors.New("Unable to generate pubkey from seckey")
+ if len(seckey) != 32 {
+ return nil, ErrInvalidKey
}
-
- return pubkey, nil
-}
-
-func Sign(msg []byte, seckey []byte) ([]byte, error) {
- msg_ptr := (*C.uchar)(unsafe.Pointer(&msg[0]))
- seckey_ptr := (*C.uchar)(unsafe.Pointer(&seckey[0]))
-
- sig := make([]byte, 65)
- sig_ptr := (*C.secp256k1_ecdsa_recoverable_signature)(unsafe.Pointer(&sig[0]))
-
- nonce := randentropy.GetEntropyCSPRNG(32)
- ndata_ptr := unsafe.Pointer(&nonce[0])
-
- noncefp_ptr := &(*C.secp256k1_nonce_function_default)
-
- if C.secp256k1_ec_seckey_verify(context, seckey_ptr) != C.int(1) {
- return nil, errors.New("Invalid secret key")
+ seckeydata := (*C.uchar)(unsafe.Pointer(&seckey[0]))
+ if C.secp256k1_ec_seckey_verify(context, seckeydata) != 1 {
+ return nil, ErrInvalidKey
}
- ret := C.secp256k1_ecdsa_sign_recoverable(
- context,
- sig_ptr,
- msg_ptr,
- seckey_ptr,
- noncefp_ptr,
- ndata_ptr,
+ var (
+ msgdata = (*C.uchar)(unsafe.Pointer(&msg[0]))
+ nonce = randentropy.GetEntropyCSPRNG(32)
+ noncefunc = &(*C.secp256k1_nonce_function_default)
+ noncefuncData = unsafe.Pointer(&nonce[0])
+ sigstruct C.secp256k1_ecdsa_recoverable_signature
)
-
- if ret == C.int(0) {
- return Sign(msg, seckey) //invalid secret, try again
+ if C.secp256k1_ecdsa_sign_recoverable(context, &sigstruct, msgdata, seckeydata, noncefunc, noncefuncData) == 0 {
+ return nil, ErrSignFailed
}
- sig_serialized := make([]byte, 65)
- sig_serialized_ptr := (*C.uchar)(unsafe.Pointer(&sig_serialized[0]))
- var recid C.int
-
- C.secp256k1_ecdsa_recoverable_signature_serialize_compact(
- context,
- sig_serialized_ptr, // 64 byte compact signature
- &recid,
- sig_ptr, // 65 byte "recoverable" signature
+ var (
+ sig = make([]byte, 65)
+ sigdata = (*C.uchar)(unsafe.Pointer(&sig[0]))
+ recid C.int
)
-
- sig_serialized[64] = byte(int(recid)) // add back recid to get 65 bytes sig
-
- return sig_serialized, nil
-
-}
-
-func VerifySeckeyValidity(seckey []byte) error {
- if len(seckey) != 32 {
- return errors.New("priv key is not 32 bytes")
- }
- var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0]))
- ret := C.secp256k1_ec_seckey_verify(context, seckey_ptr)
- if int(ret) != 1 {
- return errors.New("invalid seckey")
- }
- return nil
+ C.secp256k1_ecdsa_recoverable_signature_serialize_compact(context, sigdata, &recid, &sigstruct)
+ sig[64] = byte(recid) // add back recid to get 65 bytes sig
+ return sig, nil
}
// RecoverPubkey returns the the public key of the signer.
@@ -202,49 +121,15 @@ func RecoverPubkey(msg []byte, sig []byte) ([]byte, error) {
return nil, err
}
- msg_ptr := (*C.uchar)(unsafe.Pointer(&msg[0]))
- sig_ptr := (*C.uchar)(unsafe.Pointer(&sig[0]))
- pubkey := make([]byte, 64)
- /*
- this slice is used for both the recoverable signature and the
- resulting serialized pubkey (both types in libsecp256k1 are 65
- bytes). this saves one allocation of 65 bytes, which is nice as
- pubkey recovery is one bottleneck during load in Ethereum
- */
- bytes65 := make([]byte, 65)
- pubkey_ptr := (*C.secp256k1_pubkey)(unsafe.Pointer(&pubkey[0]))
- recoverable_sig_ptr := (*C.secp256k1_ecdsa_recoverable_signature)(unsafe.Pointer(&bytes65[0]))
- recid := C.int(sig[64])
-
- ret := C.secp256k1_ecdsa_recoverable_signature_parse_compact(
- context,
- recoverable_sig_ptr,
- sig_ptr,
- recid)
- if ret == C.int(0) {
- return nil, errors.New("Failed to parse signature")
- }
-
- ret = C.secp256k1_ecdsa_recover(
- context,
- pubkey_ptr,
- recoverable_sig_ptr,
- msg_ptr,
+ var (
+ pubkey = make([]byte, 65)
+ sigdata = (*C.uchar)(unsafe.Pointer(&sig[0]))
+ msgdata = (*C.uchar)(unsafe.Pointer(&msg[0]))
)
- if ret == C.int(0) {
- return nil, errors.New("Failed to recover public key")
+ if C.secp256k1_ecdsa_recover_pubkey(context, (*C.uchar)(unsafe.Pointer(&pubkey[0])), sigdata, msgdata) == 0 {
+ return nil, ErrRecoverFailed
}
-
- serialized_pubkey_ptr := (*C.uchar)(unsafe.Pointer(&bytes65[0]))
- var output_len C.size_t
- C.secp256k1_ec_pubkey_serialize( // always returns 1
- context,
- serialized_pubkey_ptr,
- &output_len,
- pubkey_ptr,
- 0, // SECP256K1_EC_COMPRESSED
- )
- return bytes65, nil
+ return pubkey, nil
}
func checkSignature(sig []byte) error {
generated by cgit (git 2.34.1) at 2024-11-12 22:00:34 +0800