[webcrypto] Add JWK RSA public key export for NSS.

content/child/webcrypto/platform_crypto_nss.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/webcrypto/platform_crypto.h"
 
 #include <cryptohi.h>
 #include <pk11pub.h>
 #include <sechash.h>
 
@@ skipping 677 matching lines @@
     return Status::Error();
 
   DCHECK(spki_der->data);
   DCHECK(spki_der->len);
 
   *buffer = CreateArrayBuffer(spki_der->data, spki_der->len);
 
   return Status::Success();
 }
 
+Status ExportRsaPublicKey(PublicKey* key,
+                          std::vector<uint8>* modulus,
+                          std::vector<uint8>* public_exponent) {
+  DCHECK(key);
+  DCHECK(key->key());
+
+  if (key->key()->keyType != rsaKey)
+    return Status::ErrorUnsupported();
+
+  SECItem modulus_item = key->key()->u.rsa.modulus;
+  if (!modulus_item.data || !modulus_item.len)

[eroman, 2014/03/24 22:05:51]

Consider extracting this to a function:

CopySECItemToVector(const SECItem& item, std::vector<uint8>* out);

Then you have:

CopySECItemToVector(key->key()->u.rsa.publicExponent, public_exponent);
CopySECItemToVector(key->key()->u.rsa.modulus, modulus);

if (public_exponent->empty() || modulus->empty())
  return Status::ErrorUnexpected();

[padolph, 2014/03/25 01:10:28]

Done.

+    return Status::ErrorUnexpected();
+
+  SECItem public_exponent_item = key->key()->u.rsa.publicExponent;
+  if (!public_exponent_item.data || !public_exponent_item.len)
+    return Status::ErrorUnexpected();
+
+  modulus->assign(modulus_item.data, modulus_item.data + modulus_item.len);
+  public_exponent->assign(public_exponent_item.data,
+                          public_exponent_item.data + public_exponent_item.len);
+  return Status::Success();
+}
+
 Status ImportKeyPkcs8(const blink::WebCryptoAlgorithm& algorithm,
                       const CryptoData& key_data,
                       bool extractable,
                       blink::WebCryptoKeyUsageMask usage_mask,
                       blink::WebCryptoKey* key) {
 
   DCHECK(key);
 
   if (!key_data.byte_length())
     return Status::ErrorImportEmptyKeyData();
@@ skipping 615 matching lines @@
                                      key_algorithm,
                                      usage_mask);
   return Status::Success();
 }
 
 }  // namespace platform
 
 }  // namespace webcrypto
 
 }  // namespace content