Change the WebCrypto behavior when importing EC private keys without a public key.

content/child/webcrypto/openssl/ec_algorithm_openssl.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/openssl/ec_algorithm_openssl.h"
 
 #include <openssl/ec.h>
 #include <openssl/ec_key.h>
 #include <openssl/evp.h>
 #include <openssl/pkcs12.h>
@@ skipping 87 matching lines @@
     if (kJwkCrvMappings[i].named_curve == named_curve) {
       *jwk_crv = kJwkCrvMappings[i].jwk_curve;
       return Status::Success();
     }
   }
   return Status::ErrorUnexpected();
 }
 
 // Verifies that an EC key imported from PKCS8 or SPKI format is correct.
 // This involves verifying the key validity, and the NID for the named curve.
+// Also removes the EC_PKEY_NO_PUBKEY flag if present.
 Status VerifyEcKeyAfterSpkiOrPkcs8Import(
     EVP_PKEY* pkey,
     blink::WebCryptoNamedCurve expected_named_curve) {
   crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
 
   crypto::ScopedEC_KEY ec(EVP_PKEY_get1_EC_KEY(pkey));
   if (!ec.get())
     return Status::ErrorUnexpected();
 
+  // When importing an ECPrivateKey, the public key is optional. If it was
+  // omitted then the public key will be calculated by BoringSSL and added into
+  // the EC_KEY. However an encoding flag is set such that when exporting to
+  // PKCS8 format the public key is once again omitted. Remove this flag.
+  unsigned int enc_flags = EC_KEY_get_enc_flags(ec.get());
+  enc_flags &= ~EC_PKEY_NO_PUBKEY;
+  EC_KEY_set_enc_flags(ec.get(), enc_flags);
+
   // TODO(eroman): Is this necessary? From my tests it seems that BoringSSL
   // already does these checks when setting the public key's affine coordinates.
   if (!EC_KEY_check_key(ec.get()))
     return Status::ErrorEcKeyInvalid();
 
   // Make sure the curve matches the expected curve name.
   int curve_nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec.get()));
   blink::WebCryptoNamedCurve named_curve = blink::WebCryptoNamedCurveP256;
   Status status = NidToWebCryptoCurve(curve_nid, &named_curve);
   if (status.IsError())
@@ skipping 424 matching lines @@
       key->algorithm().ecParams()->namedCurve()) {
     return Status::ErrorUnexpected();
   }
 
   return Status::Success();
 }
 
 }  // namespace webcrypto
 
 }  // namespace content