Replace hardcoded parameters

common/private_key_util.h

@@ -0,0 +1,84 @@
+////////////////////////////////////////////////////////////////////////////////
+// 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:
+//   Shared private key utilities between RSA and EC.
+
+#ifndef COMMON_PRIVATE_KEY_UTIL_H_
+#define COMMON_PRIVATE_KEY_UTIL_H_
+
+#include <string>
+
+#include "glog/logging.h"
+#include "openssl/bio.h"
+
+namespace widevine {
+namespace private_key_util {
+
+template <class Key>
+bool SerializeKey(const Key* key, int (*serialization_func)(BIO*, Key*),
+                  std::string* serialized_key) {
+  if (key == nullptr) {
+    LOG(ERROR) << "Key is nullptr.";
+    return false;
+  }
+  if (serialized_key == nullptr) {
+    LOG(ERROR) << "Pointer to hold serialized key is nullptr.";
+    return false;
+  }
+  BIO* bio = BIO_new(BIO_s_mem());
+  if (bio == nullptr) {
+    LOG(ERROR) << "BIO_new returned nullptr";
+    return false;
+  }
+  bool success = false;
+  if (serialization_func(bio, const_cast<Key*>(key)) != 0) {
+    int serialized_size = BIO_pending(bio);
+    serialized_key->assign(serialized_size, 0);
+    if (BIO_read(bio, &(*serialized_key)[0], serialized_size) ==
+        serialized_size) {
+      success = true;
+    } else {
+      LOG(ERROR) << "BIO_read failure";
+    }
+  } else {
+    LOG(ERROR) << "Key serialization failure";
+  }
+  BIO_free(bio);
+  return success;
+}
+
+template <class Key>
+bool DeserializeKey(const std::string& serialized_key,
+                    Key* (*deserialization_func)(BIO*, Key**), Key** key) {
+  if (serialized_key.empty()) {
+    LOG(ERROR) << "Serialized key is empty.";
+    return false;
+  }
+  if (key == nullptr) {
+    LOG(ERROR) << "Pointer to hold new key is nullptr.";
+    return false;
+  }
+  BIO* bio = BIO_new_mem_buf(const_cast<char*>(serialized_key.data()),
+                             serialized_key.size());
+  if (bio == nullptr) {
+    LOG(ERROR) << "BIO_new_mem_buf returned nullptr";
+    return false;
+  }
+  *key = deserialization_func(bio, nullptr);
+  BIO_free(bio);
+  if (*key == nullptr) {
+    LOG(ERROR) << "Key deserialization failure";
+  }
+  return *key != nullptr;
+}
+
+}  // namespace private_key_util
+}  // namespace widevine
+
+#endif  // COMMON_PRIVATE_KEY_UTIL_H_