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

content/child/webcrypto/platform_crypto_nss.cc

Index: content/child/webcrypto/platform_crypto_nss.cc
diff --git a/content/child/webcrypto/platform_crypto_nss.cc b/content/child/webcrypto/platform_crypto_nss.cc
index 478c7aaff73fbb6c873cdcab6465c6de80a146ec..f44cd7172e36644db24ff1c65b31be276413ab62 100644
--- a/content/child/webcrypto/platform_crypto_nss.cc
+++ b/content/child/webcrypto/platform_crypto_nss.cc
@@ -695,6 +695,30 @@ Status ExportKeySpki(PublicKey* key, blink::WebArrayBuffer* buffer) {
   return Status::Success();
 }
 
+Status ExportRsaPublicKey(PublicKey* key,
+                          blink::WebArrayBuffer* modulus,
+                          blink::WebArrayBuffer* public_exponent) {
+  DCHECK(key);
+  DCHECK(key->key());
+
+  if (key->key()->keyType != rsaKey)
+    return Status::ErrorUnsupported();
+
+  SECItem modulus_item = key->key()->u.rsa.modulus;
+  DCHECK(modulus_item.data);

[eroman, 2014/03/21 02:30:51]

Do these need to be proper returns?

[padolph, 2014/03/24 04:24:06]

Yes.

+  DCHECK(modulus_item.len);
+
+  SECItem public_exponent_item = key->key()->u.rsa.publicExponent;
+  DCHECK(public_exponent_item.data);
+  DCHECK(public_exponent_item.len);
+
+  *modulus = CreateArrayBuffer(modulus_item.data, modulus_item.len);
+  *public_exponent =
+      CreateArrayBuffer(public_exponent_item.data, public_exponent_item.len);
+
+  return Status::Success();
+}
+
 Status ImportKeyPkcs8(const blink::WebCryptoAlgorithm& algorithm,
                       const CryptoData& key_data,
                       bool extractable,