/**
 * @file llsecapi.h
 * @brief Security API for services such as certificate handling
 * secure local storage, etc.
 *
 * $LicenseInfo:firstyear=2009&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LLSECAPI_H
#define LLSECAPI_H
#include <vector>
#include "llwin32headers.h"
#include <openssl/x509.h>
#include <ostream>
#include "llpointer.h"
#include "llexception.h"

#ifdef LL_WINDOWS
#pragma warning (push)
#pragma warning(disable:4250)
#endif // LL_WINDOWS

// All error handling is via exceptions.


#define CERT_SUBJECT_NAME "subject_name"
#define CERT_ISSUER_NAME "issuer_name"
#define CERT_NAME_CN "commonName"

#define CERT_SUBJECT_NAME_STRING "subject_name_string"
#define CERT_ISSUER_NAME_STRING "issuer_name_string"

#define CERT_SERIAL_NUMBER "serial_number"

#define CERT_VALID_FROM "valid_from"
#define CERT_VALID_TO "valid_to"
#define CERT_SHA1_DIGEST "sha1_digest"
#define CERT_MD5_DIGEST "md5_digest"
#define CERT_HOSTNAME "hostname"
#define CERT_BASIC_CONSTRAINTS "basicConstraints"
#define CERT_BASIC_CONSTRAINTS_CA "CA"
#define CERT_BASIC_CONSTRAINTS_PATHLEN "pathLen"

#define CERT_KEY_USAGE "keyUsage"
#define CERT_KU_DIGITAL_SIGNATURE    "digitalSignature"
#define CERT_KU_NON_REPUDIATION      "nonRepudiation"
#define CERT_KU_KEY_ENCIPHERMENT     "keyEncipherment"
#define CERT_KU_DATA_ENCIPHERMENT    "dataEncipherment"
#define CERT_KU_KEY_AGREEMENT        "keyAgreement"
#define CERT_KU_CERT_SIGN        "certSigning"
#define CERT_KU_CRL_SIGN             "crlSigning"
#define CERT_KU_ENCIPHER_ONLY        "encipherOnly"
#define CERT_KU_DECIPHER_ONLY        "decipherOnly"

#define BASIC_SECHANDLER "BASIC_SECHANDLER"
#define CERT_VALIDATION_DATE "validation_date"

#define CERT_EXTENDED_KEY_USAGE "extendedKeyUsage"
#define CERT_EKU_SERVER_AUTH SN_server_auth
#define CERT_EKU_TLS_SERVER_AUTH LN_server_auth

#define CERT_SUBJECT_KEY_IDENTFIER "subjectKeyIdentifier"
#define CERT_AUTHORITY_KEY_IDENTIFIER "authorityKeyIdentifier"
#define CERT_AUTHORITY_KEY_IDENTIFIER_ID "authorityKeyIdentifierId"
#define CERT_AUTHORITY_KEY_IDENTIFIER_NAME "authorityKeyIdentifierName"
#define CERT_AUTHORITY_KEY_IDENTIFIER_SERIAL "authorityKeyIdentifierSerial"

// validate the current time lies within
// the validation period of the cert
#define VALIDATION_POLICY_TIME 1

// validate that the CA, or some cert in the chain
// lies within the certificate store
#define VALIDATION_POLICY_TRUSTED 2

// validate that the subject name of
// the cert contains the passed in hostname
// or validates against the hostname
#define VALIDATION_POLICY_HOSTNAME 4


// validate that the cert contains the SSL EKU
#define VALIDATION_POLICY_SSL_KU 8

// validate that the cert contains the SSL EKU
#define VALIDATION_POLICY_CA_KU 16

#define VALIDATION_POLICY_CA_BASIC_CONSTRAINTS 32

// validate that the cert is correct for SSL
#define VALIDATION_POLICY_SSL (VALIDATION_POLICY_TIME | \
                               VALIDATION_POLICY_HOSTNAME | \
                               VALIDATION_POLICY_TRUSTED | \
                               VALIDATION_POLICY_SSL_KU | \
                               VALIDATION_POLICY_CA_BASIC_CONSTRAINTS | \
                               VALIDATION_POLICY_CA_KU)






struct LLProtectedDataException: public LLException
{
    LLProtectedDataException(const std::string& msg):
        LLException(msg)
    {
        LL_WARNS("SECAPI") << "Protected Data Error: " << msg << LL_ENDL;
    }
};

// class LLCertificate
// parent class providing an interface for certifiate.
// LLCertificates are considered unmodifiable
// Certificates are pulled out of stores, or created via
// factory calls
class LLCertificate : public LLThreadSafeRefCount
{
    LOG_CLASS(LLCertificate);
public:
    LLCertificate() {}

    virtual ~LLCertificate() {}

    // return a PEM encoded certificate.  The encoding
    // includes the -----BEGIN CERTIFICATE----- and end certificate elements
    virtual std::string getPem() const=0;

    // return a DER encoded certificate
    virtual std::vector<U8> getBinary() const=0;

    // return an LLSD object containing information about the certificate
    // such as its name, signature, expiry time, serial number
    virtual void getLLSD(LLSD& llsd)=0;

    // return an openSSL X509 struct for the certificate
    virtual X509* getOpenSSLX509() const=0;

};

// class LLCertificateVector
// base class for a list of certificates.


class LLCertificateVector : public LLThreadSafeRefCount
{

public:

    LLCertificateVector() {};
    virtual ~LLCertificateVector() {};

    // base iterator implementation class, providing
    // the functionality needed for the iterator class.
    class iterator_impl : public LLThreadSafeRefCount
    {
    public:
        iterator_impl() {};
        virtual ~iterator_impl() {};
        virtual void seek(bool incr)=0;
        virtual LLPointer<iterator_impl> clone() const=0;
        virtual bool equals(const LLPointer<iterator_impl>& _iter) const=0;
        virtual LLPointer<LLCertificate> get()=0;
    };

    // iterator class
    class iterator
    {
    public:
        iterator(LLPointer<iterator_impl> impl) : mImpl(impl) {}
        iterator() : mImpl(NULL) {}
        iterator(const iterator& _iter) {mImpl = _iter.mImpl->clone(); }
        ~iterator() {}
        iterator& operator++() { if(mImpl.notNull()) mImpl->seek(true); return *this;}
        iterator& operator--() { if(mImpl.notNull()) mImpl->seek(false); return *this;}

        iterator operator++(int) { iterator result = *this; if(mImpl.notNull()) mImpl->seek(true); return result;}
        iterator operator--(int) { iterator result = *this; if(mImpl.notNull()) mImpl->seek(false); return result;}
        LLPointer<LLCertificate> operator*() { return mImpl->get(); }

        LLPointer<iterator_impl> mImpl;
    protected:
        friend bool operator==(const LLCertificateVector::iterator& _lhs, const LLCertificateVector::iterator& _rhs);
        bool equals(const iterator& _iter) const { return mImpl->equals(_iter.mImpl); }
    };

    // numeric indexer
    virtual LLPointer<LLCertificate> operator[](int)=0;

    // Iteration
    virtual iterator begin()=0;

    virtual iterator end()=0;

    // find a cert given params
    virtual iterator find(const LLSD& params) =0;

    // return the number of certs in the store
    virtual int size() const = 0;

    // append the cert to the store.  if a copy of the cert already exists in the store, it is removed first
    virtual void  add(LLPointer<LLCertificate> cert)=0;

    // insert the cert to the store.  if a copy of the cert already exists in the store, it is removed first
    virtual void  insert(iterator location, LLPointer<LLCertificate> cert)=0;

    // remove a certificate from the store
    virtual LLPointer<LLCertificate> erase(iterator cert)=0;
};

// class LLCertificateChain
// Class representing a chain of certificates in order, with the
// first element being the child cert.
class LLCertificateChain : virtual public LLCertificateVector
{

public:
    LLCertificateChain() {}

    virtual ~LLCertificateChain() {}

};

// class LLCertificateStore
// represents a store of certificates, typically a store of root CA
// certificates.  The store can be persisted, and can be used to validate
// a cert chain
//
class LLCertificateStore : virtual public LLCertificateVector
{

public:

    LLCertificateStore() {}
    virtual ~LLCertificateStore() {}

    // persist the store
    virtual void save()=0;

    // return the store id
    virtual std::string storeId() const=0;

    // validate a certificate chain given the params.
    // Will throw exceptions on error

    virtual void validate(int validation_policy,
                          LLPointer<LLCertificateChain> cert_chain,
                          const LLSD& validation_params) =0;

    // Clear cache if any
    virtual void clearSertCache()=0;
};


inline
bool operator==(const LLCertificateVector::iterator& _lhs, const LLCertificateVector::iterator& _rhs)
{
    return _lhs.equals(_rhs);
}
inline
bool operator!=(const LLCertificateVector::iterator& _lhs, const LLCertificateVector::iterator& _rhs)
{
    return !(_lhs == _rhs);
}


#define CRED_IDENTIFIER_TYPE_ACCOUNT "account"
#define CRED_IDENTIFIER_TYPE_AGENT "agent"
#define CRED_AUTHENTICATOR_TYPE_CLEAR "clear"
#define CRED_AUTHENTICATOR_TYPE_HASH   "hash"
//
// LLCredential - interface for credentials providing the following functionality:
// * Persistence of credential information based on grid (for saving username/password)
// * Serialization to an OGP identifier/authenticator pair
//
class LLCredential  : public LLThreadSafeRefCount
{
public:

    LLCredential() {}

    LLCredential(const std::string& grid)
    {
        mGrid = grid;
        mIdentifier = LLSD::emptyMap();
        mAuthenticator = LLSD::emptyMap();
    }

    virtual ~LLCredential() {}

    virtual void setCredentialData(const LLSD& identifier, const LLSD& authenticator)
    {
        mIdentifier = identifier;
        mAuthenticator = authenticator;
    }
    virtual LLSD getIdentifier() const { return mIdentifier; }
    virtual void identifierType(std::string& idType);
    virtual LLSD getAuthenticator() { return mAuthenticator; }
    virtual void authenticatorType(std::string& authType);
    virtual LLSD getLoginParams();
    virtual std::string getGrid() { return mGrid; }


    virtual void clearAuthenticator() { mAuthenticator = LLSD(); }
    virtual std::string userID() const { return std::string("unknown");}
    virtual std::string asString() const { return std::string("unknown");}
    operator std::string() const { return asString(); }
protected:
    LLSD mIdentifier;
    LLSD mAuthenticator;
    std::string mGrid;
};

std::ostream& operator <<(std::ostream& s, const LLCredential& cred);


// All error handling is via exceptions.

class LLCertException: public LLException
{
public:
    LLCertException(const LLSD& cert_data, const std::string& msg);
    virtual ~LLCertException() throw() {}
    LLSD getCertData() const { return mCertData; }
protected:
    LLSD mCertData;
};

class LLAllocationCertException : public LLCertException
{
public:
    LLAllocationCertException(const LLSD& cert_data) : LLCertException(cert_data, "CertAllocationFailure")
    {
    }
    virtual ~LLAllocationCertException() throw() {}
protected:
};

class LLInvalidCertificate : public LLCertException
{
public:
    LLInvalidCertificate(const LLSD& cert_data) : LLCertException(cert_data, "CertInvalid")
    {
    }
    virtual ~LLInvalidCertificate() throw() {}
protected:
};

class LLCertValidationTrustException : public LLCertException
{
public:
    LLCertValidationTrustException(const LLSD& cert_data) : LLCertException(cert_data, "CertUntrusted")
    {
    }
    virtual ~LLCertValidationTrustException() throw() {}
protected:
};

class LLCertValidationHostnameException : public LLCertException
{
public:
    LLCertValidationHostnameException(std::string hostname,
                                      const LLSD& cert_data) : LLCertException(cert_data, "CertInvalidHostname")
    {
        mHostname = hostname;
    }
    virtual ~LLCertValidationHostnameException() throw() {}
    std::string getHostname() { return mHostname; }
protected:
    std::string mHostname;
};

class LLCertValidationExpirationException : public LLCertException
{
public:
    LLCertValidationExpirationException(const LLSD& cert_data,
                                        LLDate current_time) : LLCertException(cert_data, "CertExpired")
    {
        mTime = current_time;
    }
    virtual ~LLCertValidationExpirationException() throw() {}
    LLDate GetTime() { return mTime; }
protected:
    LLDate mTime;
};

class LLCertKeyUsageValidationException : public LLCertException
{
public:
    LLCertKeyUsageValidationException(const LLSD& cert_data) : LLCertException(cert_data, "CertKeyUsage")
    {
    }
    virtual ~LLCertKeyUsageValidationException() throw() {}
protected:
};

class LLCertBasicConstraintsValidationException : public LLCertException
{
public:
    LLCertBasicConstraintsValidationException(const LLSD& cert_data) : LLCertException(cert_data, "CertBasicConstraints")
    {
    }
    virtual ~LLCertBasicConstraintsValidationException() throw() {}
protected:
};

class LLCertValidationInvalidSignatureException : public LLCertException
{
public:
    LLCertValidationInvalidSignatureException(const LLSD& cert_data) : LLCertException(cert_data, "CertInvalidSignature")
    {
    }
    virtual ~LLCertValidationInvalidSignatureException() throw() {}
protected:
};

// LLSecAPIHandler Class
// Interface handler class for the various security storage handlers.
class LLSecAPIHandler : public LLThreadSafeRefCount
{
public:


    LLSecAPIHandler() {}
    virtual ~LLSecAPIHandler() {}

    // initialize the SecAPIHandler
    virtual void init() {};

    // instantiate a certificate from a pem string
    virtual LLPointer<LLCertificate> getCertificate(const std::string& pem_cert)=0;



    // instiate a certificate from an openssl X509 structure
    virtual LLPointer<LLCertificate> getCertificate(X509* openssl_cert)=0;

    // instantiate a chain from an X509_STORE_CTX
    virtual LLPointer<LLCertificateChain> getCertificateChain(X509_STORE_CTX* chain)=0;

    // instantiate a cert store given it's id.  if a persisted version
    // exists, it'll be loaded.  If not, one will be created (but not
    // persisted)
    virtual LLPointer<LLCertificateStore> getCertificateStore(const std::string& store_id)=0;

    // persist data in a protected store
    virtual void setProtectedData(const std::string& data_type,
                                  const std::string& data_id,
                                  const LLSD& data)=0;

    // retrieve protected data
    virtual LLSD getProtectedData(const std::string& data_type,
                                  const std::string& data_id)=0;

    // delete a protected data item from the store
    virtual void deleteProtectedData(const std::string& data_type,
                                     const std::string& data_id)=0;

    // persist data in a protected store's map
    virtual void addToProtectedMap(const std::string& data_type,
                                   const std::string& data_id,
                                   const std::string& map_elem,
                                   const LLSD& data)=0;

    // remove data from protected store's map
    virtual void removeFromProtectedMap(const std::string& data_type,
                                        const std::string& data_id,
                                        const std::string& map_elem)=0;

    // ensure protected store's map is written to storage
    virtual void syncProtectedMap() = 0;

public:
    virtual LLPointer<LLCredential> createCredential(const std::string& grid,
                                                     const LLSD& identifier,
                                                     const LLSD& authenticator)=0;

    virtual LLPointer<LLCredential> loadCredential(const std::string& grid)=0;

    virtual void saveCredential(LLPointer<LLCredential> cred, bool save_authenticator)=0;

    virtual void deleteCredential(LLPointer<LLCredential> cred)=0;

    // has map of credentials declared as specific storage
    virtual bool hasCredentialMap(const std::string& storage,
                                  const std::string& grid)=0;

    // returns true if map is empty or does not exist
    virtual bool emptyCredentialMap(const std::string& storage,
                                    const std::string& grid)=0;

    // load map of credentials from specific storage
    typedef std::map<std::string, LLPointer<LLCredential> > credential_map_t;
    virtual void loadCredentialMap(const std::string& storage,
                                   const std::string& grid,
                                   credential_map_t& credential_map)=0;

    // load single username from map of credentials from specific storage
    virtual LLPointer<LLCredential> loadFromCredentialMap(const std::string& storage,
                                                          const std::string& grid,
                                                          const std::string& userid)=0;

    // add item to map of credentials from specific storage
    virtual void addToCredentialMap(const std::string& storage,
                                    LLPointer<LLCredential> cred,
                                    bool save_authenticator)=0;

    // remove item from map of credentials from specific storage
    virtual void removeFromCredentialMap(const std::string& storage,
                                         LLPointer<LLCredential> cred)=0;

    // remove item from map of credentials from specific storage
    virtual void removeFromCredentialMap(const std::string& storage,
                                         const std::string& grid,
                                         const std::string& userid)=0;

    virtual void removeCredentialMap(const std::string& storage,
                                     const std::string& grid)=0;

};

void initializeSecHandler();

void clearSecHandler();

// retrieve a security api depending on the api type
LLPointer<LLSecAPIHandler> getSecHandler(const std::string& handler_type);

void registerSecHandler(const std::string& handler_type,
                        LLPointer<LLSecAPIHandler>& handler);

extern LLPointer<LLSecAPIHandler> gSecAPIHandler;

#ifdef LL_WINDOWS
#pragma warning (pop)
#endif // LL_WINDOWS

#endif // LL_SECAPI_H