winscp/source/putty/windows/winstore.c

/*
 * winstore.c: Windows-specific implementation of the interface
 * defined in storage.h.
 */

#ifdef MPEXT

#include "puttyexp.h"

#pragma option push -w-dup
#define RegOpenKey reg_open_winscp_key
#define RegCreateKey reg_create_winscp_key
#define RegQueryValueEx reg_query_winscp_value_ex
#define RegSetValueEx reg_set_winscp_value_ex
#define RegCloseKey reg_close_winscp_key
#pragma option pop

#endif

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <assert.h>
#include "putty.h"
#include "storage.h"

#include <shlobj.h>
#ifndef CSIDL_APPDATA
#define CSIDL_APPDATA 0x001a
#endif
#ifndef CSIDL_LOCAL_APPDATA
#define CSIDL_LOCAL_APPDATA 0x001c
#endif

static const char *const reg_jumplist_key = PUTTY_REG_POS "\\Jumplist";
static const char *const reg_jumplist_value = "Recent sessions";
static const char *const puttystr = PUTTY_REG_POS "\\Sessions";

static bool tried_shgetfolderpath = false;
static HMODULE shell32_module = NULL;
DECL_WINDOWS_FUNCTION(static, HRESULT, SHGetFolderPathA,
                      (HWND, int, HANDLE, DWORD, LPSTR));

struct settings_w {
    HKEY sesskey;
};

settings_w *open_settings_w(const char *sessionname, char **errmsg)
{
    HKEY subkey1, sesskey;
    int ret;
    strbuf *sb;

    *errmsg = NULL;

    if (!sessionname || !*sessionname)
        sessionname = "Default Settings";

    sb = strbuf_new();
    escape_registry_key(sessionname, sb);

    ret = RegCreateKey(HKEY_CURRENT_USER, puttystr, &subkey1);
    if (ret != ERROR_SUCCESS) {
        strbuf_free(sb);
        *errmsg = dupprintf("Unable to create registry key\n"
                            "HKEY_CURRENT_USER\\%s", puttystr);
        return NULL;
    }
    ret = RegCreateKey(subkey1, sb->s, &sesskey);
    RegCloseKey(subkey1);
    if (ret != ERROR_SUCCESS) {
        *errmsg = dupprintf("Unable to create registry key\n"
                            "HKEY_CURRENT_USER\\%s\\%s", puttystr, sb->s);
        strbuf_free(sb);
        return NULL;
    }
    strbuf_free(sb);

    { // WINSCP
    settings_w *toret = snew(settings_w);
    toret->sesskey = sesskey;
    return toret;
    } // WINSCP
}

void write_setting_s(settings_w *handle, const char *key, const char *value)
{
    if (handle)
        RegSetValueEx(handle->sesskey, key, 0, REG_SZ, (CONST BYTE *)value,
                      1 + strlen(value));
}

void write_setting_i(settings_w *handle, const char *key, int value)
{
    if (handle)
        RegSetValueEx(handle->sesskey, key, 0, REG_DWORD,
                      (CONST BYTE *) &value, sizeof(value));
}

void close_settings_w(settings_w *handle)
{
    RegCloseKey(handle->sesskey);
    sfree(handle);
}

struct settings_r {
    HKEY sesskey;
};

settings_r *open_settings_r(const char *sessionname)
{
    HKEY subkey1, sesskey;
    strbuf *sb;

    if (!sessionname || !*sessionname)
        sessionname = "Default Settings";

    sb = strbuf_new();
    escape_registry_key(sessionname, sb);

    if (RegOpenKey(HKEY_CURRENT_USER, puttystr, &subkey1) != ERROR_SUCCESS) {
        sesskey = NULL;
    } else {
        if (RegOpenKey(subkey1, sb->s, &sesskey) != ERROR_SUCCESS) {
            sesskey = NULL;
        }
        RegCloseKey(subkey1);
    }

    strbuf_free(sb);

    if (!sesskey)
        return NULL;

    { // WINSCP
    settings_r *toret = snew(settings_r);
    toret->sesskey = sesskey;
    return toret;
    } // WINSCP
}

char *read_setting_s(settings_r *handle, const char *key)
{
    DWORD type, allocsize, size;
    char *ret;

    if (!handle)
        return NULL;

    /* Find out the type and size of the data. */
    if (RegQueryValueEx(handle->sesskey, key, 0,
                        &type, NULL, &size) != ERROR_SUCCESS ||
        type != REG_SZ)
        return NULL;

    allocsize = size+1;         /* allow for an extra NUL if needed */
    ret = snewn(allocsize, char);
    if (RegQueryValueEx(handle->sesskey, key, 0,
                        &type, (BYTE *)ret, &size) != ERROR_SUCCESS ||
        type != REG_SZ) {
        sfree(ret);
        return NULL;
    }
    assert(size < allocsize);
    ret[size] = '\0'; /* add an extra NUL in case RegQueryValueEx
                       * didn't supply one */

    return ret;
}

int read_setting_i(settings_r *handle, const char *key, int defvalue)
{
    DWORD type, val, size;
    size = sizeof(val);

    if (!handle ||
        RegQueryValueEx(handle->sesskey, key, 0, &type,
                        (BYTE *) &val, &size) != ERROR_SUCCESS ||
        size != sizeof(val) || type != REG_DWORD)
        return defvalue;
    else
        return val;
}

FontSpec *read_setting_fontspec(settings_r *handle, const char *name)
{
    char *settingname;
    char *fontname;
    FontSpec *ret;
    int isbold, height, charset;

    fontname = read_setting_s(handle, name);
    if (!fontname)
        return NULL;

    settingname = dupcat(name, "IsBold");
    isbold = read_setting_i(handle, settingname, -1);
    sfree(settingname);
    if (isbold == -1) {
        sfree(fontname);
        return NULL;
    }

    settingname = dupcat(name, "CharSet");
    charset = read_setting_i(handle, settingname, -1);
    sfree(settingname);
    if (charset == -1) {
        sfree(fontname);
        return NULL;
    }

    settingname = dupcat(name, "Height");
    height = read_setting_i(handle, settingname, INT_MIN);
    sfree(settingname);
    if (height == INT_MIN) {
        sfree(fontname);
        return NULL;
    }

    ret = fontspec_new(fontname, isbold, height, charset);
    sfree(fontname);
    return ret;
}

void write_setting_fontspec(settings_w *handle,
                            const char *name, FontSpec *font)
{
    char *settingname;

    write_setting_s(handle, name, font->name);
    settingname = dupcat(name, "IsBold");
    write_setting_i(handle, settingname, font->isbold);
    sfree(settingname);
    settingname = dupcat(name, "CharSet");
    write_setting_i(handle, settingname, font->charset);
    sfree(settingname);
    settingname = dupcat(name, "Height");
    write_setting_i(handle, settingname, font->height);
    sfree(settingname);
}

Filename *read_setting_filename(settings_r *handle, const char *name)
{
    char *tmp = read_setting_s(handle, name);
    if (tmp) {
        Filename *ret = filename_from_str(tmp);
        sfree(tmp);
        return ret;
    } else
        return NULL;
}

void write_setting_filename(settings_w *handle,
                            const char *name, Filename *result)
{
    write_setting_s(handle, name, result->path);
}

void close_settings_r(settings_r *handle)
{
    if (handle) {
        RegCloseKey(handle->sesskey);
        sfree(handle);
    }
}

void del_settings(const char *sessionname)
{
    HKEY subkey1;
    strbuf *sb;

    if (RegOpenKey(HKEY_CURRENT_USER, puttystr, &subkey1) != ERROR_SUCCESS)
        return;

    sb = strbuf_new();
    escape_registry_key(sessionname, sb);
    RegDeleteKey(subkey1, sb->s);
    strbuf_free(sb);

    RegCloseKey(subkey1);

    remove_session_from_jumplist(sessionname);
}

struct settings_e {
    HKEY key;
    int i;
};

settings_e *enum_settings_start(void)
{
    settings_e *ret;
    HKEY key;

    if (RegOpenKey(HKEY_CURRENT_USER, puttystr, &key) != ERROR_SUCCESS)
        return NULL;

    ret = snew(settings_e);
    if (ret) {
        ret->key = key;
        ret->i = 0;
    }

    return ret;
}

bool enum_settings_next(settings_e *e, strbuf *sb)
{
    size_t regbuf_size = MAX_PATH + 1;
    char *regbuf = snewn(regbuf_size, char);
    bool success;

    while (1) {
        DWORD retd = RegEnumKey(e->key, e->i, regbuf, regbuf_size);
        if (retd != ERROR_MORE_DATA) {
            success = (retd == ERROR_SUCCESS);
            break;
        }
        sgrowarray(regbuf, regbuf_size, regbuf_size);
    }

    if (success)
        unescape_registry_key(regbuf, sb);

    e->i++;
    sfree(regbuf);
    return success;
}

void enum_settings_finish(settings_e *e)
{
    RegCloseKey(e->key);
    sfree(e);
}

static void hostkey_regname(strbuf *sb, const char *hostname,
                            int port, const char *keytype)
{
    strbuf_catf(sb, "%s@%d:", keytype, port);
    escape_registry_key(hostname, sb);
}

#ifdef MPEXT
int retrieve_host_key(const char *hostname, int port,
		    const char *keytype, char *key, int maxlen)
#else
int verify_host_key(const char *hostname, int port,
                    const char *keytype, const char *key)
#endif
{
    char *otherstr;
    strbuf *regname;
    int len;
    HKEY rkey;
    DWORD readlen;
    DWORD type;
    int ret, compare;

#ifdef MPEXT
    len = maxlen;
#else
    len = 1 + strlen(key);
#endif

    /*
     * Now read a saved key in from the registry and see what it
     * says.
     */
    regname = strbuf_new();
    hostkey_regname(regname, hostname, port, keytype);

    if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_POS "\\SshHostKeys",
                   &rkey) != ERROR_SUCCESS) {
        strbuf_free(regname);
        return 1;                      /* key does not exist in registry */
    }

    readlen = len;
    otherstr = snewn(len, char);
    ret = RegQueryValueEx(rkey, regname->s, NULL,
                          &type, (BYTE *)otherstr, &readlen);

    if (ret != ERROR_SUCCESS && ret != ERROR_MORE_DATA &&
        !strcmp(keytype, "rsa")) {
        /*
         * Key didn't exist. If the key type is RSA, we'll try
         * another trick, which is to look up the _old_ key format
         * under just the hostname and translate that.
         */
        char *justhost = regname->s + 1 + strcspn(regname->s, ":");
        char *oldstyle = snewn(len + 10, char); /* safety margin */
        readlen = len;
        ret = RegQueryValueEx(rkey, justhost, NULL, &type,
                              (BYTE *)oldstyle, &readlen);

        if (ret == ERROR_SUCCESS && type == REG_SZ) {
            /*
             * The old format is two old-style bignums separated by
             * a slash. An old-style bignum is made of groups of
             * four hex digits: digits are ordered in sensible
             * (most to least significant) order within each group,
             * but groups are ordered in silly (least to most)
             * order within the bignum. The new format is two
             * ordinary C-format hex numbers (0xABCDEFG...XYZ, with
             * A nonzero except in the special case 0x0, which
             * doesn't appear anyway in RSA keys) separated by a
             * comma. All hex digits are lowercase in both formats.
             */
            char *p = otherstr;
            char *q = oldstyle;
            int i, j;

            for (i = 0; i < 2; i++) {
                int ndigits, nwords;
                *p++ = '0';
                *p++ = 'x';
                ndigits = strcspn(q, "/");      /* find / or end of string */
                nwords = ndigits / 4;
                /* now trim ndigits to remove leading zeros */
                while (q[(ndigits - 1) ^ 3] == '0' && ndigits > 1)
                    ndigits--;
                /* now move digits over to new string */
                for (j = 0; j < ndigits; j++)
                    p[ndigits - 1 - j] = q[j ^ 3];
                p += ndigits;
                q += nwords * 4;
                if (*q) {
                    q++;               /* eat the slash */
                    *p++ = ',';        /* add a comma */
                }
                *p = '\0';             /* terminate the string */
            }

            /*
             * Now _if_ this key matches, we'll enter it in the new
             * format. If not, we'll assume something odd went
             * wrong, and hyper-cautiously do nothing.
             */
            if (!strcmp(otherstr, key))
                RegSetValueEx(rkey, regname->s, 0, REG_SZ, (BYTE *)otherstr,
                              strlen(otherstr) + 1);
        }

        sfree(oldstyle);
    }

    RegCloseKey(rkey);

#ifdef MPEXT
    // make sure it is zero terminated, what it is not, particularly when
    // RegQueryValueEx fails (the key is unknown)
    otherstr[len - 1] = '\0';
#endif
#ifdef MPEXT
    strncpy(key, otherstr, maxlen);
    key[maxlen - 1] = '\0';
#else
    compare = strcmp(otherstr, key);
#endif

    sfree(otherstr);
    strbuf_free(regname);

#ifndef MPEXT
    if (ret == ERROR_MORE_DATA ||
        (ret == ERROR_SUCCESS && type == REG_SZ && compare))
        return 2;                      /* key is different in registry */
    else
#endif
    if (ret != ERROR_SUCCESS || type != REG_SZ)
        return 1;                      /* key does not exist in registry */
    else
        return 0;                      /* key matched OK in registry */
}

#ifndef MPEXT
bool have_ssh_host_key(const char *hostname, int port,
                      const char *keytype)
{
    /*
     * If we have a host key, verify_host_key will return 0 or 2.
     * If we don't have one, it'll return 1.
     */
    return verify_host_key(hostname, port, keytype, "") != 1;
}
#endif

void store_host_key(const char *hostname, int port,
                    const char *keytype, const char *key)
{
    strbuf *regname;
    HKEY rkey;

    regname = strbuf_new();
    hostkey_regname(regname, hostname, port, keytype);

    if (RegCreateKey(HKEY_CURRENT_USER, PUTTY_REG_POS "\\SshHostKeys",
                     &rkey) == ERROR_SUCCESS) {
        RegSetValueEx(rkey, regname->s, 0, REG_SZ,
                      (BYTE *)key, strlen(key) + 1);
        RegCloseKey(rkey);
    } /* else key does not exist in registry */

    strbuf_free(regname);
}

/*
 * Open (or delete) the random seed file.
 */
enum { DEL, OPEN_R, OPEN_W };
static bool try_random_seed(char const *path, int action, HANDLE *ret)
{
    if (action == DEL) {
        if (!DeleteFile(path) && GetLastError() != ERROR_FILE_NOT_FOUND) {
            nonfatal("Unable to delete '%s': %s", path,
                     win_strerror(GetLastError()));
        }
        *ret = INVALID_HANDLE_VALUE;
        return false;                  /* so we'll do the next ones too */
    }

    *ret = CreateFile(path,
                      action == OPEN_W ? GENERIC_WRITE : GENERIC_READ,
                      action == OPEN_W ? 0 : (FILE_SHARE_READ |
                                              FILE_SHARE_WRITE),
                      NULL,
                      action == OPEN_W ? CREATE_ALWAYS : OPEN_EXISTING,
                      action == OPEN_W ? FILE_ATTRIBUTE_NORMAL : 0,
                      NULL);

    return (*ret != INVALID_HANDLE_VALUE);
}

static bool try_random_seed_and_free(char *path, int action, HANDLE *hout)
{
    bool retd = try_random_seed(path, action, hout);
    sfree(path);
    return retd;
}

static HANDLE access_random_seed(int action)
{
    HKEY rkey;
    HANDLE rethandle;

    /*
     * Iterate over a selection of possible random seed paths until
     * we find one that works.
     *
     * We do this iteration separately for reading and writing,
     * meaning that we will automatically migrate random seed files
     * if a better location becomes available (by reading from the
     * best location in which we actually find one, and then
     * writing to the best location in which we can _create_ one).
     */

    /*
     * First, try the location specified by the user in the
     * Registry, if any.
     */
    {
        char regpath[MAX_PATH + 1];
        DWORD type, size = sizeof(regpath);
        if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_POS, &rkey) ==
            ERROR_SUCCESS) {
            int ret = RegQueryValueEx(rkey, "RandSeedFile",
                                      0, &type, (BYTE *)regpath, &size);
            RegCloseKey(rkey);
            if (ret == ERROR_SUCCESS && type == REG_SZ &&
                try_random_seed(regpath, action, &rethandle))
                return rethandle;
        }
    }

    /*
     * Next, try the user's local Application Data directory,
     * followed by their non-local one. This is found using the
     * SHGetFolderPath function, which won't be present on all
     * versions of Windows.
     */
    if (!tried_shgetfolderpath) {
        /* This is likely only to bear fruit on systems with IE5+
         * installed, or WinMe/2K+. There is some faffing with
         * SHFOLDER.DLL we could do to try to find an equivalent
         * on older versions of Windows if we cared enough.
         * However, the invocation below requires IE5+ anyway,
         * so stuff that. */
        shell32_module = load_system32_dll("shell32.dll");
        GET_WINDOWS_FUNCTION(shell32_module, SHGetFolderPathA);
        tried_shgetfolderpath = true;
    }
    if (p_SHGetFolderPathA) {
        char profile[MAX_PATH + 1];
        if (SUCCEEDED(p_SHGetFolderPathA(NULL, CSIDL_LOCAL_APPDATA,
                                         NULL, SHGFP_TYPE_CURRENT, profile)) &&
            try_random_seed_and_free(dupcat(profile, "\\PUTTY.RND"),
                                     action, &rethandle))
            return rethandle;

        if (SUCCEEDED(p_SHGetFolderPathA(NULL, CSIDL_APPDATA,
                                         NULL, SHGFP_TYPE_CURRENT, profile)) &&
            try_random_seed_and_free(dupcat(profile, "\\PUTTY.RND"),
                                     action, &rethandle))
            return rethandle;
    }

    /*
     * Failing that, try %HOMEDRIVE%%HOMEPATH% as a guess at the
     * user's home directory.
     */
    {
        char drv[MAX_PATH], path[MAX_PATH];

        DWORD drvlen = GetEnvironmentVariable("HOMEDRIVE", drv, sizeof(drv));
        DWORD pathlen = GetEnvironmentVariable("HOMEPATH", path, sizeof(path));

        /* We permit %HOMEDRIVE% to expand to an empty string, but if
         * %HOMEPATH% does that, we abort the attempt. Same if either
         * variable overflows its buffer. */
        if (drvlen == 0)
            drv[0] = '\0';

        if (drvlen < lenof(drv) && pathlen < lenof(path) && pathlen > 0 &&
            try_random_seed_and_free(
                dupcat(drv, path, "\\PUTTY.RND"), action, &rethandle))
            return rethandle;
    }

    /*
     * And finally, fall back to C:\WINDOWS.
     */
    {
        char windir[MAX_PATH];
        DWORD len = GetWindowsDirectory(windir, sizeof(windir));
        if (len < lenof(windir) &&
            try_random_seed_and_free(
                dupcat(windir, "\\PUTTY.RND"), action, &rethandle))
            return rethandle;
    }

    /*
     * If even that failed, give up.
     */
    return INVALID_HANDLE_VALUE;
}

void read_random_seed(noise_consumer_t consumer)
{
    HANDLE seedf = access_random_seed(OPEN_R);

    if (seedf != INVALID_HANDLE_VALUE) {
        while (1) {
            char buf[1024];
            DWORD len;

            if (ReadFile(seedf, buf, sizeof(buf), &len, NULL) && len)
                consumer(buf, len);
            else
                break;
        }
        CloseHandle(seedf);
    }
}

void write_random_seed(void *data, int len)
{
    HANDLE seedf = access_random_seed(OPEN_W);

    if (seedf != INVALID_HANDLE_VALUE) {
        DWORD lenwritten;

        WriteFile(seedf, data, len, &lenwritten, NULL);
        CloseHandle(seedf);
    }
}

/*
 * Internal function supporting the jump list registry code. All the
 * functions to add, remove and read the list have substantially
 * similar content, so this is a generalisation of all of them which
 * transforms the list in the registry by prepending 'add' (if
 * non-null), removing 'rem' from what's left (if non-null), and
 * returning the resulting concatenated list of strings in 'out' (if
 * non-null).
 */
static int transform_jumplist_registry
    (const char *add, const char *rem, char **out)
{
    int ret;
    HKEY pjumplist_key;
    DWORD type;
    DWORD value_length;
    char *old_value, *new_value;
    char *piterator_old, *piterator_new, *piterator_tmp;

    ret = RegCreateKeyEx(HKEY_CURRENT_USER, reg_jumplist_key, 0, NULL,
                         REG_OPTION_NON_VOLATILE, (KEY_READ | KEY_WRITE), NULL,
                         &pjumplist_key, NULL);
    if (ret != ERROR_SUCCESS) {
        return JUMPLISTREG_ERROR_KEYOPENCREATE_FAILURE;
    }

    /* Get current list of saved sessions in the registry. */
    value_length = 200;
    old_value = snewn(value_length, char);
    ret = RegQueryValueEx(pjumplist_key, reg_jumplist_value, NULL, &type,
                          (BYTE *)old_value, &value_length);
    /* When the passed buffer is too small, ERROR_MORE_DATA is
     * returned and the required size is returned in the length
     * argument. */
    if (ret == ERROR_MORE_DATA) {
        sfree(old_value);
        old_value = snewn(value_length, char);
        ret = RegQueryValueEx(pjumplist_key, reg_jumplist_value, NULL, &type,
                              (BYTE *)old_value, &value_length);
    }

    if (ret == ERROR_FILE_NOT_FOUND) {
        /* Value doesn't exist yet. Start from an empty value. */
        *old_value = '\0';
        *(old_value + 1) = '\0';
    } else if (ret != ERROR_SUCCESS) {
        /* Some non-recoverable error occurred. */
        sfree(old_value);
        RegCloseKey(pjumplist_key);
        return JUMPLISTREG_ERROR_VALUEREAD_FAILURE;
    } else if (type != REG_MULTI_SZ) {
        /* The value present in the registry has the wrong type: we
         * try to delete it and start from an empty value. */
        ret = RegDeleteValue(pjumplist_key, reg_jumplist_value);
        if (ret != ERROR_SUCCESS) {
            sfree(old_value);
            RegCloseKey(pjumplist_key);
            return JUMPLISTREG_ERROR_VALUEREAD_FAILURE;
        }

        *old_value = '\0';
        *(old_value + 1) = '\0';
    }

    /* Check validity of registry data: REG_MULTI_SZ value must end
     * with \0\0. */
    piterator_tmp = old_value;
    while (((piterator_tmp - old_value) < (value_length - 1)) &&
           !(*piterator_tmp == '\0' && *(piterator_tmp+1) == '\0')) {
        ++piterator_tmp;
    }

    if ((piterator_tmp - old_value) >= (value_length-1)) {
        /* Invalid value. Start from an empty value. */
        *old_value = '\0';
        *(old_value + 1) = '\0';
    }

    /*
     * Modify the list, if we're modifying.
     */
    if (add || rem) {
        /* Walk through the existing list and construct the new list of
         * saved sessions. */
        new_value = snewn(value_length + (add ? strlen(add) + 1 : 0), char);
        piterator_new = new_value;
        piterator_old = old_value;

        /* First add the new item to the beginning of the list. */
        if (add) {
            strcpy(piterator_new, add);
            piterator_new += strlen(piterator_new) + 1;
        }
        /* Now add the existing list, taking care to leave out the removed
         * item, if it was already in the existing list. */
        while (*piterator_old != '\0') {
            if (!rem || strcmp(piterator_old, rem) != 0) {
                /* Check if this is a valid session, otherwise don't add. */
                settings_r *psettings_tmp = open_settings_r(piterator_old);
                if (psettings_tmp != NULL) {
                    close_settings_r(psettings_tmp);
                    strcpy(piterator_new, piterator_old);
                    piterator_new += strlen(piterator_new) + 1;
                }
            }
            piterator_old += strlen(piterator_old) + 1;
        }
        *piterator_new = '\0';
        ++piterator_new;

        /* Save the new list to the registry. */
        ret = RegSetValueEx(pjumplist_key, reg_jumplist_value, 0, REG_MULTI_SZ,
                            (BYTE *)new_value, piterator_new - new_value);

        sfree(old_value);
        old_value = new_value;
    } else
        ret = ERROR_SUCCESS;

    /*
     * Either return or free the result.
     */
    if (out && ret == ERROR_SUCCESS)
        *out = old_value;
    else
        sfree(old_value);

    /* Clean up and return. */
    RegCloseKey(pjumplist_key);

    if (ret != ERROR_SUCCESS) {
        return JUMPLISTREG_ERROR_VALUEWRITE_FAILURE;
    } else {
        return JUMPLISTREG_OK;
    }
}

/* Adds a new entry to the jumplist entries in the registry. */
int add_to_jumplist_registry(const char *item)
{
    return transform_jumplist_registry(item, item, NULL);
}

/* Removes an item from the jumplist entries in the registry. */
int remove_from_jumplist_registry(const char *item)
{
    return transform_jumplist_registry(NULL, item, NULL);
}

/* Returns the jumplist entries from the registry. Caller must free
 * the returned pointer. */
char *get_jumplist_registry_entries (void)
{
    char *list_value;

    if (transform_jumplist_registry(NULL,NULL,&list_value) != JUMPLISTREG_OK) {
        list_value = snewn(2, char);
        *list_value = '\0';
        *(list_value + 1) = '\0';
    }
    return list_value;
}

/*
 * Recursively delete a registry key and everything under it.
 */
static void registry_recursive_remove(HKEY key)
{
    DWORD i;
    char name[MAX_PATH + 1];
    HKEY subkey;

    i = 0;
    while (RegEnumKey(key, i, name, sizeof(name)) == ERROR_SUCCESS) {
        if (RegOpenKey(key, name, &subkey) == ERROR_SUCCESS) {
            registry_recursive_remove(subkey);
            RegCloseKey(subkey);
        }
        RegDeleteKey(key, name);
    }
}

void cleanup_all(void)
{
    HKEY key;
    int ret;
    char name[MAX_PATH + 1];

    /* ------------------------------------------------------------
     * Wipe out the random seed file, in all of its possible
     * locations.
     */
    access_random_seed(DEL);

    /* ------------------------------------------------------------
     * Ask Windows to delete any jump list information associated
     * with this installation of PuTTY.
     */
    clear_jumplist();

    /* ------------------------------------------------------------
     * Destroy all registry information associated with PuTTY.
     */

    /*
     * Open the main PuTTY registry key and remove everything in it.
     */
    if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_POS, &key) ==
        ERROR_SUCCESS) {
        registry_recursive_remove(key);
        RegCloseKey(key);
    }
    /*
     * Now open the parent key and remove the PuTTY main key. Once
     * we've done that, see if the parent key has any other
     * children.
     */
    if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_PARENT,
                   &key) == ERROR_SUCCESS) {
        RegDeleteKey(key, PUTTY_REG_PARENT_CHILD);
        ret = RegEnumKey(key, 0, name, sizeof(name));
        RegCloseKey(key);
        /*
         * If the parent key had no other children, we must delete
         * it in its turn. That means opening the _grandparent_
         * key.
         */
        if (ret != ERROR_SUCCESS) {
            if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_GPARENT,
                           &key) == ERROR_SUCCESS) {
                RegDeleteKey(key, PUTTY_REG_GPARENT_CHILD);
                RegCloseKey(key);
            }
        }
    }
    /*
     * Now we're done.
     */
}