[WebCrypto] Throw syntaxError if keyUsage is empty in ImportKey

content/child/webcrypto/nss/aes_key_nss.cc

Index: content/child/webcrypto/nss/aes_key_nss.cc
diff --git a/content/child/webcrypto/nss/aes_key_nss.cc b/content/child/webcrypto/nss/aes_key_nss.cc
index d6a7fd9cb514026bfdd5ae6fbc95daee87ca3ac4..07e223e91695e6a07e6a66d0fb6473aae231a89e 100644
--- a/content/child/webcrypto/nss/aes_key_nss.cc
+++ b/content/child/webcrypto/nss/aes_key_nss.cc
@@ -72,6 +72,9 @@ Status AesAlgorithm::ImportKeyRaw(const CryptoData& key_data,
                                   bool extractable,
                                   blink::WebCryptoKeyUsageMask usages,
                                   blink::WebCryptoKey* key) const {
+  if (usages == 0)
+    return Status::ErrorImportKeyEmptyUsages();

[eroman, 2014/12/08 18:46:32]

Move this into VerifyKeyUsagesBeforeImportKey() similar to the other usage
checks. (Necessary for early failure when unwrapping keys).

In fact it would be best to just modify the CheckKeyCreationUsages() helper to
do the check. Add for instance a bool parameter indicating if empty usages are
allowed.

+
   const unsigned int keylen_bytes = key_data.byte_length();
   Status status = VerifyAesKeyLengthForImport(keylen_bytes);
   if (status.IsError())
@@ -91,6 +94,9 @@ Status AesAlgorithm::ImportKeyJwk(const CryptoData& key_data,
                                   bool extractable,
                                   blink::WebCryptoKeyUsageMask usages,
                                   blink::WebCryptoKey* key) const {
+  if (usages == 0)
+    return Status::ErrorImportKeyEmptyUsages();
+
   std::vector<uint8_t> raw_data;
   Status status = ReadAesSecretKeyJwk(key_data, jwk_suffix_, extractable,
                                       usages, &raw_data);