Refactor RSA key generation for WebCrypto's NSS implementation.

content/child/webcrypto/webcrypto_util.h

 // 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.
 
 #ifndef CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_
 #define CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_
 
 #include <stdint.h>
 #include <string>
 #include <vector>
@@ skipping 69 matching lines @@
                                 unsigned int* keylen_bits);
 
 Status GetHmacKeyGenLengthInBits(const blink::WebCryptoHmacKeyGenParams* params,
                                  unsigned int* keylen_bits);
 
 Status VerifyAesKeyLengthForImport(unsigned int keylen_bytes);
 
 Status CheckKeyCreationUsages(blink::WebCryptoKeyUsageMask all_possible_usages,
                               blink::WebCryptoKeyUsageMask actual_usages);
 
+// Extracts the public exponent and modulus length from the Blink parameters.
+// On success it is guaranteed that:
+//   * public_exponent is either 3 or 65537
+//   * modulus_length_bits is a multiple of 8
+//   * modulus_length is >= 256
+//   * modulus_length is <= 16K
+Status GetRsaKeyGenParameters(
+    const blink::WebCryptoRsaHashedKeyGenParams* params,
+    unsigned int* public_exponent,
+    unsigned int* modulus_length_bits);
+
 }  // namespace webcrypto
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_WEBCRYPTO_WEBCRYPTO_UTIL_H_