Replace hardcoded parameters

common/ec_util.h

@@ -0,0 +1,87 @@
+////////////////////////////////////////////////////////////////////////////////
+// Copyright 2019 Google LLC.
+//
+// This software is licensed under the terms defined in the Widevine Master
+// License Agreement. For a copy of this agreement, please contact
+// widevine-licensing@google.com.
+////////////////////////////////////////////////////////////////////////////////
+//
+// Description:
+//   Utility functions to deserialize and serialize EC keys.
+
+#ifndef COMMON_EC_UTIL_H_
+#define COMMON_EC_UTIL_H_
+
+#include <string>
+
+#include "openssl/ec.h"
+#include "common/ec_key.h"
+
+namespace widevine {
+namespace ec_util {
+
+// Serialize EC private key into DER encoded RFC5915 std::string.
+// Parameter |private_key| is the EC private key to be serialized.
+// Parameter |serialized_private_key| will hold the serialized private key.
+// Caller retains ownership of all pointers and they cannot be nullptr.
+// Returns true if successful, false otherwise.
+bool SerializeECPrivateKey(const EC_KEY* private_key,
+                           std::string* serialized_private_key);
+
+// Deserialized DER encoded RFC5915 std::string into an EC private key.
+// Parameter |serialized_private_key| contains the serialized private key.
+// Parameter |private_key| will hold the deserialized EC private key.
+// Caller retains ownership of all pointers and they cannot be nullptr.
+// Returns true if successful, false otherwise.
+bool DeserializeECPrivateKey(const std::string& serialized_private_key,
+                             EC_KEY** private_key);
+
+// Serialize EC public key into DER encoded RFC5208 std::string.
+// Parameter |public_key| is the EC public key to be serialized.
+// Parameter |serialized_public_key| will hold the serialized public key.
+// Caller retains ownership of all pointers and they cannot be nullptr.
+// Returns true if successful, false otherwise.
+bool SerializeECPublicKey(const EC_KEY* public_key,
+                          std::string* serialized_public_key);
+
+// Deserialized DER encoded RFC5208 std::string into an EC private key.
+// Parameter |serialized_public_key| contains the serialized public key.
+// Parameter |public_key| will hold the deserialized EC public key.
+// Caller retains ownership of all pointers and they cannot be nullptr.
+// Returns true if successful, false otherwise.
+bool DeserializeECPublicKey(const std::string& serialized_public_key,
+                            EC_KEY** public_key);
+
+// Returns the expected size of the encoded public key keypoint for the given
+// key |curve|.
+size_t GetPublicKeyPointSize(ECPrivateKey::EllipticCurve curve);
+
+// Returns the public key from the |ec_key| encoded per X9.62.
+bool GetPublicKeyPoint(const EC_KEY* ec_key, std::string* encoded_key);
+
+// Returns a |public_key| for the given curve, deserialized from the
+// X9.62 |key_point|.  |key_point| is required to be in uncompressed format and
+// the correct size for the given curve.
+bool GetPublicKeyFromKeyPoint(ECPrivateKey::EllipticCurve curve,
+                              const std::string& key_point,
+                              EC_KEY** public_key);
+
+// Convert |nid| to its corresponding EllipticCurve value if supported.
+// Parameter |nid| corresponds to one of the macros in nid.h.
+// Returns a valid EllipticCurve if |nid| is supported and UNDEFINED_CURVE
+// otherwise.
+ECPrivateKey::EllipticCurve NidToCurve(int nid);
+
+// Convert |curve| to its corresponding NID value.
+// Parameter |curve| is an accepted curve value.
+// Returns the NID that corresponds to the curve in nid.h if it exists and
+// NID_undef otherwise.
+int CurveToNid(ECPrivateKey::EllipticCurve curve);
+
+// Creates a new ECKey using the provided |curve|.
+ScopedECKEY GenerateKeyWithCurve(ECPrivateKey::EllipticCurve curve);
+
+}  // namespace ec_util
+}  // namespace widevine
+
+#endif  // COMMON_EC_UTIL_H_