Add an ECDH Wycheproof driver.

Unfortunately, this driver suffers a lot from Wycheproof's Java
heritgate, but so it goes. Their test formats bake in a lot of Java API

Change-Id: I3299e85efb58e99e4fa34841709c3bea6518968d
Reviewed-by: Steven Valdez <>
Commit-Queue: David Benjamin <>
CQ-Verified: CQ bot account: <>
diff --git a/crypto/test/wycheproof_util.h b/crypto/test/wycheproof_util.h
index cf50b8e..4d8a14c 100644
--- a/crypto/test/wycheproof_util.h
+++ b/crypto/test/wycheproof_util.h
@@ -41,5 +41,10 @@
 bssl::UniquePtr<EC_GROUP> GetWycheproofCurve(FileTest *t, const char *key,
                                              bool instruction);
+// GetWycheproofBIGNUM returns a BIGNUM in the Wycheproof format, or nullptr on
+// error.
+bssl::UniquePtr<BIGNUM> GetWycheproofBIGNUM(FileTest *t, const char *key,
+                                            bool instruction);