make allocate/use/defer dances more consistent in ECDSA sig extraction

1 files changed, 8 insertions, 9 deletions

diff --git a/src/regress/lib/libcrypto/wycheproof/wycheproof.go b/src/regress/lib/libcrypto/wycheproof/wycheproof.go
index ee99050b3e..1a5aac87f1 100644
--- a/src/regress/lib/libcrypto/wycheproof/wycheproof.go
+++ b/src/regress/lib/libcrypto/wycheproof/wycheproof.go
@@ -1,4 +1,4 @@
-/* $OpenBSD: wycheproof.go,v 1.70 2018/10/05 21:12:43 tb Exp $ */
+/* $OpenBSD: wycheproof.go,v 1.71 2018/10/06 04:35:54 tb Exp $ */
 /*
  * Copyright (c) 2018 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2018 Theo Buehler <tb@openbsd.org>
@@ -1373,16 +1373,15 @@ func runECDSAWebCryptoTest(ecKey *C.EC_KEY, nid int, h hash.Hash, wt *wycheproof
         }
 
         // DER encode the signature (so that ECDSA_verify() can decode and encode it again...)
-        sigLen := len(wt.Sig)
-        r := C.CString(wt.Sig[:sigLen/2])
-        s := C.CString(wt.Sig[sigLen/2:])
-
         cSig := C.ECDSA_SIG_new()
-        defer C.ECDSA_SIG_free(cSig)
-
         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:])
         if C.BN_hex2bn(&cSig.r, r) == 0 {
                 log.Fatal("Failed to set ECDSA r")
         }
@@ -1396,13 +1395,13 @@ func runECDSAWebCryptoTest(ecKey *C.EC_KEY, nid int, h hash.Hash, wt *wycheproof
         if derLen == 0 {
                 log.Fatal("i2d_ECDSA_SIG(cSig, nil) failed")
         }
-
         cDer := (*C.uchar)(C.malloc(C.ulong(derLen)))
         if cDer == nil {
                 log.Fatal("malloc failed")
         }
-        p := cDer
         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)