factor ECDSA signature extraction into its own function

1 files changed, 35 insertions, 24 deletions

diff --git a/regress/lib/libcrypto/wycheproof/wycheproof.go b/regress/lib/libcrypto/wycheproof/wycheproof.go
index 1a5aac87f14..c7ea7689395 100644
--- a/regress/lib/libcrypto/wycheproof/wycheproof.go
+++ b/regress/lib/libcrypto/wycheproof/wycheproof.go
@@ -1,4 +1,4 @@
-/* $OpenBSD: wycheproof.go,v 1.71 2018/10/06 04:35:54 tb Exp $ */
+/* $OpenBSD: wycheproof.go,v 1.72 2018/10/06 05:02:21 tb Exp $ */
 /*
  * Copyright (c) 2018 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2018 Theo Buehler <tb@openbsd.org>
@@ -1357,31 +1357,17 @@ func runECDSATestGroup(algorithm string, wtg *wycheproofTestGroupECDSA) bool {
 	return success
 }
 
-func runECDSAWebCryptoTest(ecKey *C.EC_KEY, nid int, h hash.Hash, wt *wycheproofTestECDSA) bool {
-	msg, err := hex.DecodeString(wt.Msg)
-	if err != nil {
-		log.Fatalf("Failed to decode message %q: %v", wt.Msg, err)
-	}
-
-	h.Reset()
-	h.Write(msg)
-	msg = h.Sum(nil)
-
-	msgLen := len(msg)
-	if msgLen == 0 {
-		msg = append(msg, 0)
-	}
-
-	// DER encode the signature (so that ECDSA_verify() can decode and encode it again...)
+// DER encode the signature (so that ECDSA_verify() can decode and encode it again...)
+func encodeECDSAWebCryptoSig(wtSig string) (*C.uchar, C.int) {
 	cSig := C.ECDSA_SIG_new()
 	if cSig == nil {
 		log.Fatal("ECDSA_SIG_new() failed")
 	}
 	defer C.ECDSA_SIG_free(cSig)
 
-	sigLen := len(wt.Sig)
-	r := C.CString(wt.Sig[:sigLen/2])
-	s := C.CString(wt.Sig[sigLen/2:])
+	sigLen := len(wtSig)
+	r := C.CString(wtSig[:sigLen/2])
+	s := C.CString(wtSig[sigLen/2:])
 	if C.BN_hex2bn(&cSig.r, r) == 0 {
 		log.Fatal("Failed to set ECDSA r")
 	}
@@ -1393,21 +1379,46 @@ func runECDSAWebCryptoTest(ecKey *C.EC_KEY, nid int, h hash.Hash, wt *wycheproof
 
 	derLen := C.i2d_ECDSA_SIG(cSig, nil)
 	if derLen == 0 {
-		log.Fatal("i2d_ECDSA_SIG(cSig, nil) failed")
+		return nil, 0
 	}
 	cDer := (*C.uchar)(C.malloc(C.ulong(derLen)))
 	if cDer == nil {
 		log.Fatal("malloc failed")
 	}
-	defer C.free(unsafe.Pointer(cDer))
 
 	p := cDer
 	ret := C.i2d_ECDSA_SIG(cSig, (**C.uchar)(&p))
 	if ret == 0 || ret != derLen {
-		log.Fatalf("i2d_ECDSA_SIG(cSig, nil) failed, got %d, want %d", ret, derLen)
+		C.free(unsafe.Pointer(cDer))
+		return nil, 0
 	}
 
-	ret = C.ECDSA_verify(0, (*C.uchar)(unsafe.Pointer(&msg[0])), C.int(msgLen),
+	return cDer, derLen
+}
+
+func runECDSAWebCryptoTest(ecKey *C.EC_KEY, nid int, h hash.Hash, wt *wycheproofTestECDSA) bool {
+	msg, err := hex.DecodeString(wt.Msg)
+	if err != nil {
+		log.Fatalf("Failed to decode message %q: %v", wt.Msg, err)
+	}
+
+	h.Reset()
+	h.Write(msg)
+	msg = h.Sum(nil)
+
+	msgLen := len(msg)
+	if msgLen == 0 {
+		msg = append(msg, 0)
+	}
+
+	cDer, derLen := encodeECDSAWebCryptoSig(wt.Sig)
+	if cDer == nil {
+		fmt.Print("FAIL: unable to decode signature")
+		return false
+	}
+	defer C.free(unsafe.Pointer(cDer))
+
+	ret := C.ECDSA_verify(0, (*C.uchar)(unsafe.Pointer(&msg[0])), C.int(msgLen),
 		(*C.uchar)(unsafe.Pointer(cDer)), C.int(derLen), ecKey)
 
 	// XXX audit acceptable cases...