// 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 CHROME_BROWSER_CHROMEOS_PLATFORM_KEYS_PLATFORM_KEYS_H_
#define CHROME_BROWSER_CHROMEOS_PLATFORM_KEYS_PLATFORM_KEYS_H_

#include <string>
#include <vector>

#include "base/callback_forward.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "net/cert/x509_certificate.h"

namespace content {
class BrowserContext;
}

namespace chromeos {

namespace platform_keys {

// A token is a store for keys or certs and can provide cryptographic
// operations.
// ChromeOS provides itself a user token and conditionally a system wide token,
// thus these tokens use static identifiers. The platform keys API is designed
// to support arbitrary other tokens in the future, which could then use
// run-time generated IDs.
extern const char kTokenIdUser[];
extern const char kTokenIdSystem[];

// Supported hash algorithms.
enum HashAlgorithm {
  HASH_ALGORITHM_NONE,  // The value if no hash function is selected.
  HASH_ALGORITHM_SHA1,
  HASH_ALGORITHM_SHA256,
  HASH_ALGORITHM_SHA384,
  HASH_ALGORITHM_SHA512
};

struct ClientCertificateRequest {
  ClientCertificateRequest();
  ~ClientCertificateRequest();

  // The list of the types of certificates requested, sorted in order of the
  // server's preference.
  std::vector<net::X509Certificate::PublicKeyType> certificate_key_types;

  // List of distinguished names of certificate authorities allowed by the
  // server. Each entry must be a DER-encoded X.509 DistinguishedName.
  std::vector<std::string> certificate_authorities;
};

namespace subtle {
// Functions of this namespace shouldn't be called directly from the context of
// an extension. Instead use PlatformKeysService which enforces restrictions
// upon extensions.

typedef base::Callback<void(const std::string& public_key_spki_der,
                            const std::string& error_message)>
    GenerateKeyCallback;

// Generates a RSA key pair with |modulus_length_bits|. |token_id| is currently
// ignored, instead the user token associated with |browser_context| is always
// used. |callback| will be invoked with the resulting public key or an error.
void GenerateRSAKey(const std::string& token_id,
                    unsigned int modulus_length_bits,
                    const GenerateKeyCallback& callback,
                    content::BrowserContext* browser_context);

typedef base::Callback<void(const std::string& signature,
                            const std::string& error_message)> SignCallback;

// Digests |data|, applies PKCS1 padding and afterwards signs the data with the
// private key matching |params.public_key|. If a non empty token id is provided
// and the key is not found in that token, the operation aborts. |callback| will
// be invoked with the signature or an error message.
void SignRSAPKCS1Digest(const std::string& token_id,
                        const std::string& data,
                        const std::string& public_key,
                        HashAlgorithm hash_algorithm,
                        const SignCallback& callback,
                        content::BrowserContext* browser_context);

// Applies PKCS1 padding and afterwards signs the data with the private key
// matching |params.public_key|. |data| is not digested. If a non empty token id
// is provided and the key is not found in that token, the operation aborts.
// The size of |data| (number of octets) must be smaller than k - 11, where k
// is the key size in octets.
// |callback| will be invoked with the signature or an error message.
void SignRSAPKCS1Raw(const std::string& token_id,
                     const std::string& data,
                     const std::string& public_key,
                     const SignCallback& callback,
                     content::BrowserContext* browser_context);

// If the certificate request could be processed successfully, |matches| will
// contain the list of matching certificates (which may be empty) and
// |error_message| will be empty. If an error occurred, |matches| will be null
// and |error_message| contain an error message.
typedef base::Callback<void(scoped_ptr<net::CertificateList> matches,
                            const std::string& error_message)>
    SelectCertificatesCallback;

// Returns the list of all certificates that were issued by one of the
// |certificate_authorities|. If |certificate_authorities| is empty, all
// certificates will be returned. |callback| will be invoked with the matches or
// an error message.
void SelectClientCertificates(
    const std::vector<std::string>& certificate_authorities,
    const SelectCertificatesCallback& callback,
    content::BrowserContext* browser_context);

}  // namespace subtle

// Returns the DER encoding of the X.509 Subject Public Key Info of the public
// key in |certificate|.
std::string GetSubjectPublicKeyInfo(
    const scoped_refptr<net::X509Certificate>& certificate);

// Obtains information about the public key in |certificate|.
// If |certificate| contains an RSA key, sets |key_size_bits| to the modulus
// length, and |key_type| to type RSA and returns true.
// If |certificate| contains any other key type, or if the public exponent of
// the RSA key in |certificate| is not F4, returns false and does not update any
// of the output parameters.
// All pointer arguments must not be null.
bool GetPublicKey(const scoped_refptr<net::X509Certificate>& certificate,
                  net::X509Certificate::PublicKeyType* key_type,
                  size_t* key_size_bits);

// If the list of certificates could be successfully retrieved, |certs| will
// contain the list of available certificates (maybe empty) and |error_message|
// will be empty. If an error occurred, |certs| will be empty and
// |error_message| contain an error message.
typedef base::Callback<void(scoped_ptr<net::CertificateList> certs,
                            const std::string& error_message)>
    GetCertificatesCallback;

// Returns the list of all certificates with stored private key available from
// the given token. |token_id| is currently ignored, instead the user token
// associated with |browser_context| is always used. |callback| will be invoked
// with the list of available certificates or an error message.
void GetCertificates(const std::string& token_id,
                     const GetCertificatesCallback& callback,
                     content::BrowserContext* browser_context);

// If an error occurred during import, |error_message| will be set to an error
// message.
typedef base::Callback<void(const std::string& error_message)>
    ImportCertificateCallback;

// Imports |certificate| to the given token if the certified key is already
// stored in this token. Any intermediate of |certificate| will be ignored.
// |token_id| is currently ignored, instead the user token associated with
// |browser_context| is always used. |callback| will be invoked when the import
// is finished, possibly with an error message.
void ImportCertificate(const std::string& token_id,
                       const scoped_refptr<net::X509Certificate>& certificate,
                       const ImportCertificateCallback& callback,
                       content::BrowserContext* browser_context);

// If an error occurred during removal, |error_message| will be set to an error
// message.
typedef base::Callback<void(const std::string& error_message)>
    RemoveCertificateCallback;

// Removes |certificate| from the given token if present. Any intermediate of
// |certificate| will be ignored. |token_id| is currently ignored, instead the
// user token associated with |browser_context| is always used. |callback| will
// be invoked when the removal is finished, possibly with an error message.
void RemoveCertificate(const std::string& token_id,
                       const scoped_refptr<net::X509Certificate>& certificate,
                       const RemoveCertificateCallback& callback,
                       content::BrowserContext* browser_context);

// If the list of available tokens could be successfully retrieved, |token_ids|
// will contain the token ids. If an error occurs, |token_ids| will be NULL and
// |error_message| will be set to an error message.
typedef base::Callback<void(scoped_ptr<std::vector<std::string> > token_ids,
                            const std::string& error_message)>
    GetTokensCallback;

// Gets the list of available tokens. |callback| will be invoked when the list
// of available tokens is determined, possibly with an error message.
// Must be called and calls |callback| on the UI thread.
void GetTokens(const GetTokensCallback& callback,
               content::BrowserContext* browser_context);

}  // namespace platform_keys

}  // namespace chromeos

#endif  // CHROME_BROWSER_CHROMEOS_PLATFORM_KEYS_PLATFORM_KEYS_H_