// This file is under GNU General Public License 3.0

// see LICENSE.txt

#define PEP_ENGINE_VERSION "0.8.0"

// maximum attachment size to import as key 1MB, maximum of 20 attachments

#define MAX_KEY_SIZE (1024 * 1024)

#define MAX_KEYS_TO_IMPORT  20

// this is 20 trustwords with 79 chars max

#define MAX_TRUSTWORDS_SPACE (20 * 80)

// XML parameters string

#define PARMS_MAX 32768

// maximum busy wait time in ms

#define BUSY_WAIT_TIME 5000

// maximum line length for reading gpg.conf

#define MAX_LINELENGTH 1024

// default keyserver

#ifndef DEFAULT_KEYSERVER

#define DEFAULT_KEYSERVER "hkp://keys.gnupg.net"

#endif

// crashdump constants

#ifndef CRASHDUMP_DEFAULT_LINES

#define CRASHDUMP_DEFAULT_LINES 100

#endif

#define CRASHDUMP_MAX_LINES 32767

#include "platform.h"

#ifdef WIN32

#define LOCAL_DB windoze_local_db()

#define SYSTEM_DB windoze_system_db()

#define LIBGPGME "libgpgme-11.dll"

#else // UNIX

#define _POSIX_C_SOURCE 200809L

#include <dlfcn.h>

#define LOCAL_DB unix_local_db()

#ifndef SYSTEM_DB

#define SYSTEM_DB "/usr/share/pEp/system.db"

#endif

#ifndef LIBGPGME

#define LIBGPGME "libgpgme-pthread.so"

#endif

#endif

#include <locale.h>

#include <stdlib.h>

#include <string.h>

#include <assert.h>

#include <stdio.h>

#include <ctype.h>

#include "sqlite3.h"

#define _EXPORT_PEP_ENGINE_DLL

#include "pEpEngine.h"

// If not specified, build for GPG

#ifndef USE_NETPGP

#ifndef USE_GPG

#define USE_GPG

#endif

#endif

#ifdef USE_GPG

#include "pgp_gpg_internal.h"

#elif defined(USE_NETPGP)

#include "pgp_netpgp_internal.h"

#endif

#include "keymanagement.h"

#include "cryptotech.h"

#include "transport.h"

#include "sync.h"

#define NOT_IMPLEMENTED assert(0); return PEP_UNKNOWN_ERROR;

struct _pEpSession;

typedef struct _pEpSession pEpSession;

struct _pEpSession {

    const char *version;

#ifdef USE_GPG

    gpgme_ctx_t ctx;

#elif defined(USE_NETPGP)

    pEpNetPGPSession ctx;

#endif

    PEP_cryptotech_t *cryptotech;

    PEP_transport_t *transports;

    sqlite3 *db;

    sqlite3 *system_db;

    sqlite3_stmt *log;

    sqlite3_stmt *trustword;

    sqlite3_stmt *get_identity;

    sqlite3_stmt *set_person;

    sqlite3_stmt *set_device_group;

    sqlite3_stmt *get_device_group;

    sqlite3_stmt *set_pgp_keypair;

    sqlite3_stmt *set_identity;

    sqlite3_stmt *set_identity_flags;

    sqlite3_stmt *unset_identity_flags;

    sqlite3_stmt *set_trust;

    sqlite3_stmt *get_trust;

    sqlite3_stmt *least_trust;

    sqlite3_stmt *mark_compromized;

    sqlite3_stmt *reset_trust;

    sqlite3_stmt *crashdump;

    sqlite3_stmt *languagelist;

    sqlite3_stmt *i18n_token;

    // blacklist

    sqlite3_stmt *blacklist_add;

    sqlite3_stmt *blacklist_delete;

    sqlite3_stmt *blacklist_is_listed;

    sqlite3_stmt *blacklist_retrieve;

    // Own keys

    sqlite3_stmt *own_key_is_listed;

    sqlite3_stmt *own_identities_retrieve;

    sqlite3_stmt *own_keys_retrieve;

    sqlite3_stmt *set_own_key;

    // sequence value

    sqlite3_stmt *sequence_value1;

    sqlite3_stmt *sequence_value2;

    sqlite3_stmt *sequence_value3;

    // revoked keys

    sqlite3_stmt *set_revoked;

    sqlite3_stmt *get_revoked;

    // callbacks

    examine_identity_t examine_identity;

    void *examine_management;

    void *sync_management;

    void *sync_obj;

    messageToSend_t messageToSend;

    notifyHandshake_t notifyHandshake;

    inject_sync_msg_t inject_sync_msg;

    retrieve_next_sync_msg_t retrieve_next_sync_msg;

    // key sync

    pEpSession* sync_session;

    DeviceState_state sync_state;

    void* sync_state_payload;

    char sync_uuid[37];

    time_t LastCannotDecrypt;

    time_t LastUpdateRequest;

    // runtime config

    bool passive_mode;

    bool unencrypted_subject;

    bool use_only_own_private_keys;

    bool keep_sync_msg;

};

PEP_STATUS init_transport_system(PEP_SESSION session, bool in_first);

void release_transport_system(PEP_SESSION session, bool out_last);

/* NOT to be exposed to the outside!!! */

PEP_STATUS encrypt_only(

        PEP_SESSION session, const stringlist_t *keylist, const char *ptext,

        size_t psize, char **ctext, size_t *csize

);

#ifdef NDEBUG

#define DEBUG_LOG(TITLE, ENTITY, DESC)

#else

#ifdef ANDROID

#include <android/log.h>

#define  LOG_MORE(...)  __android_log_print(ANDROID_LOG_DEBUG, "pEpEngine", " %s :: %s :: %s ", __VA_ARGS__);

#else

#include <stdio.h>

#define  LOG_MORE(...)  printf("pEpEngine DEBUG_LOG('%s','%s','%s')\n", __VA_ARGS__);

#endif

#define DEBUG_LOG(TITLE, ENTITY, DESC) {\

    log_event(session, (TITLE), (ENTITY), (DESC), "debug");\

    LOG_MORE((TITLE), (ENTITY), (DESC))\

}

#endif

typedef enum _normalize_hex_rest_t {

    accept_hex,

    ignore_hex,

    reject_hex

} normalize_hex_res_t;

static inline normalize_hex_res_t _normalize_hex(char *hex) 

{

    if (*hex >= '0' && *hex <= '9')

        return accept_hex;

    if (*hex >= 'A' && *hex <= 'F') {

        *hex += 'a' - 'A';

        return accept_hex;

    }

    if (*hex >= 'a' && *hex <= 'f') 

        return accept_hex;

    if (*hex == ' ') 

        return ignore_hex;

    return reject_hex;

}

// Space tolerant and case insensitive fingerprint string compare

static inline PEP_STATUS _compare_fprs(

        const char* fpra,

        size_t fpras,

        const char* fprb,

        size_t fprbs,

        int* comparison)

{

    size_t ai = 0;

    size_t bi = 0;

    size_t significant = 0;

    int _comparison = 0;

    const int _FULL_FINGERPRINT_LENGTH = 40;

    // First compare every non-ignored chars until an end is reached

    while(ai < fpras && bi < fprbs)

    {

        char fprac = fpra[ai];

        char fprbc = fprb[bi];

        normalize_hex_res_t fprah = _normalize_hex(&fprac);

        normalize_hex_res_t fprbh = _normalize_hex(&fprbc);

        if(fprah == reject_hex || fprbh == reject_hex)

            return PEP_ILLEGAL_VALUE;

        if ( fprah == ignore_hex )

        {

            ai++;

        }

        else if ( fprbh == ignore_hex )

        {

            bi++;

        }

        else

        {

            if(fprac != fprbc && _comparison == 0 )

            {

                _comparison = fprac > fprbc ? 1 : -1;

            }

            significant++;

            ai++;

            bi++;

        } 

    }

    // Bail out if we didn't got enough significnt chars

    if (significant != _FULL_FINGERPRINT_LENGTH )

        return PEP_TRUSTWORDS_FPR_WRONG_LENGTH;

    // Then purge remaining chars, all must be ignored chars

    while ( ai < fpras )

    {

        char fprac = fpra[ai];

        normalize_hex_res_t fprah = _normalize_hex(&fprac);

        if( fprah == reject_hex )

            return PEP_ILLEGAL_VALUE;

        if ( fprah != ignore_hex )

            return PEP_TRUSTWORDS_FPR_WRONG_LENGTH;

        ai++;

    }

    while ( bi < fprbs )

    {

        char fprbc = fprb[bi];

        normalize_hex_res_t fprbh = _normalize_hex(&fprbc);

        if( fprbh == reject_hex )

            return PEP_ILLEGAL_VALUE;

        if ( fprbh != ignore_hex )

            return PEP_TRUSTWORDS_FPR_WRONG_LENGTH;

        bi++;

    }

    *comparison = _comparison;

    return PEP_STATUS_OK;

}

static inline int _same_fpr(

        const char* fpra,

        size_t fpras,

        const char* fprb,

        size_t fprbs

    )

{

    // illegal values are ignored, and considered not same.

    int comparison = 1;

    _compare_fprs(fpra, fpras, fprb, fprbs, &comparison);

    return comparison == 0;

}