[webcrypto] Implement RSA-OAEP using BoringSSL.

content/child/webcrypto/openssl/rsa_oaep_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 <openssl/evp.h>
+
+#include "base/stl_util.h"
+#include "content/child/webcrypto/crypto_data.h"
+#include "content/child/webcrypto/openssl/key_openssl.h"
+#include "content/child/webcrypto/openssl/rsa_key_openssl.h"
+#include "content/child/webcrypto/openssl/util_openssl.h"
+#include "content/child/webcrypto/status.h"
+#include "crypto/openssl_util.h"
+#include "crypto/scoped_openssl_types.h"
+#include "third_party/WebKit/public/platform/WebCryptoAlgorithmParams.h"
+#include "third_party/WebKit/public/platform/WebCryptoKeyAlgorithm.h"
+
+namespace content {
+
+namespace webcrypto {
+
+namespace {
+
+typedef int (*InitFunc)(EVP_PKEY_CTX* ctx);
+typedef int (*EncryptDecryptFunc)(EVP_PKEY_CTX* ctx,
+                                  unsigned char* out,
+                                  size_t* outlen,
+                                  const unsigned char* in,
+                                  size_t inlen);
+
+// Helper for doing either RSA-OAEP encryption or decryption.
+//
+// To encrypt call with:
+//   init_func=EVP_PKEY_encrypt_init, encrypt_decrypt_func=EVP_PKEY_encrypt
+//
+// To decrypt call with:
+//   init_func=EVP_PKEY_decrypt_init, encrypt_decrypt_func=EVP_PKEY_decrypt
+Status CommonEncryptDecrypt(InitFunc init_func,
+                            EncryptDecryptFunc encrypt_decrypt_func,
+                            const blink::WebCryptoAlgorithm& algorithm,
+                            const blink::WebCryptoKey& key,
+                            const CryptoData& data,
+                            std::vector<uint8_t>* buffer) {
+  crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
+
+  EVP_PKEY* pkey = AsymKeyOpenSsl::Cast(key)->key();
+  const EVP_MD* digest =
+      GetDigest(key.algorithm().rsaHashedParams()->hash().id());
+  if (!digest)
+    return Status::ErrorUnsupported();
+
+  crypto::ScopedEVP_PKEY_CTX ctx(EVP_PKEY_CTX_new(pkey, NULL));
+
+  if (1 != init_func(ctx.get()) ||
+      1 != EVP_PKEY_CTX_set_rsa_padding(ctx.get(), RSA_PKCS1_OAEP_PADDING) ||
+      1 != EVP_PKEY_CTX_set_rsa_oaep_md(ctx.get(), digest) ||
+      1 != EVP_PKEY_CTX_set_rsa_mgf1_md(ctx.get(), digest)) {
+    return Status::OperationError();
+  }
+
+  const blink::WebVector<uint8_t>& label =
+      algorithm.rsaOaepParams()->optionalLabel();
+
+  if (label.size()) {
+    // Make a copy of the label, since the ctx takes ownership of it when
+    // calling set0_rsa_oaep_label().
+    crypto::ScopedOpenSSLBytes label_copy;
+    label_copy.reset(static_cast<uint8_t*>(OPENSSL_malloc(label.size())));
+    memcpy(label_copy.get(), label.data(), label.size());
+
+    if (1 != EVP_PKEY_CTX_set0_rsa_oaep_label(
+                 ctx.get(), label_copy.release(), label.size())) {
+      return Status::OperationError();
+    }
+  }
+
+  // Determine the maximum length of the output.
+  size_t outlen = 0;
+  if (1 != encrypt_decrypt_func(
+               ctx.get(), NULL, &outlen, data.bytes(), data.byte_length())) {
+    return Status::OperationError();
+  }
+  buffer->resize(outlen);
+
+  // Do the actual encryption/decryption.
+  if (1 != encrypt_decrypt_func(ctx.get(),
+                                vector_as_array(buffer),
+                                &outlen,
+                                data.bytes(),
+                                data.byte_length())) {
+    return Status::OperationError();
+  }
+  buffer->resize(outlen);
+
+  return Status::Success();
+}
+
+class RsaOaepImplementation : public RsaHashedAlgorithm {
+ public:
+  RsaOaepImplementation()
+      : RsaHashedAlgorithm(
+            blink::WebCryptoKeyUsageEncrypt | blink::WebCryptoKeyUsageWrapKey,
+            blink::WebCryptoKeyUsageDecrypt |
+                blink::WebCryptoKeyUsageUnwrapKey) {}
+
+  virtual const char* GetJwkAlgorithm(
+      const blink::WebCryptoAlgorithmId hash) const OVERRIDE {
+    switch (hash) {
+      case blink::WebCryptoAlgorithmIdSha1:
+        return "RSA-OAEP";
+      case blink::WebCryptoAlgorithmIdSha256:
+        return "RSA-OAEP-256";
+      case blink::WebCryptoAlgorithmIdSha384:
+        return "RSA-OAEP-384";
+      case blink::WebCryptoAlgorithmIdSha512:
+        return "RSA-OAEP-512";
+      default:
+        return NULL;
+    }
+  }
+
+  virtual Status Encrypt(const blink::WebCryptoAlgorithm& algorithm,
+                         const blink::WebCryptoKey& key,
+                         const CryptoData& data,
+                         std::vector<uint8_t>* buffer) const OVERRIDE {
+    if (key.type() != blink::WebCryptoKeyTypePublic)
+      return Status::ErrorUnexpectedKeyType();
+
+    return CommonEncryptDecrypt(
+        EVP_PKEY_encrypt_init, EVP_PKEY_encrypt, algorithm, key, data, buffer);
+  }
+
+  virtual Status Decrypt(const blink::WebCryptoAlgorithm& algorithm,
+                         const blink::WebCryptoKey& key,
+                         const CryptoData& data,
+                         std::vector<uint8_t>* buffer) const OVERRIDE {
+    if (key.type() != blink::WebCryptoKeyTypePrivate)
+      return Status::ErrorUnexpectedKeyType();
+
+    return CommonEncryptDecrypt(
+        EVP_PKEY_decrypt_init, EVP_PKEY_decrypt, algorithm, key, data, buffer);
+  }
+};
+
+}  // namespace
+
+AlgorithmImplementation* CreatePlatformRsaOaepImplementation() {
+  return new RsaOaepImplementation;
+}
+
+}  // namespace webcrypto
+
+}  // namespace content