qga/commands-windows-ssh.c - qemu - Git at Google

 /*
  * QEMU Guest Agent win32-specific command implementations for SSH keys.
  * The implementation is opinionated and expects the SSH implementation to
  * be OpenSSH.
  *
  * Copyright Schweitzer Engineering Laboratories. 2024
  *
  * Authors:
  *  Aidan Leuck <aidan_leuck@selinc.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */

 #include "qemu/osdep.h"
 #include <aclapi.h>
 #include <qga-qapi-types.h>

 #include "commands-common-ssh.h"
 #include "commands-windows-ssh.h"
 #include "guest-agent-core.h"
 #include "limits.h"
 #include "lmaccess.h"
 #include "lmapibuf.h"
 #include "lmerr.h"
 #include "qapi/error.h"

 #include "qga-qapi-commands.h"
 #include "sddl.h"
 #include "shlobj.h"
 #include "userenv.h"

 #define AUTHORIZED_KEY_FILE "authorized_keys"
 #define AUTHORIZED_KEY_FILE_ADMIN "administrators_authorized_keys"
 #define LOCAL_SYSTEM_SID "S-1-5-18"
 #define ADMIN_SID "S-1-5-32-544"

 /*
  * Frees userInfo structure. This implements the g_auto cleanup
  * for the structure.
  */
 void free_userInfo(PWindowsUserInfo info)
 {
     g_free(info->sshDirectory);
     g_free(info->authorizedKeyFile);
     LocalFree(info->SSID);
     g_free(info->username);
     g_free(info);
 }

 /*
  * Gets the admin SSH folder for OpenSSH. OpenSSH does not store
  * the authorized_key file in the users home directory for security reasons and
  * instead stores it at %PROGRAMDATA%/ssh. This function returns the path to
  * that directory on the users machine
  *
  * parameters:
  * errp -> error structure to set when an error occurs
  * returns: The path to the ssh folder in %PROGRAMDATA% or NULL if an error
  * occurred.
  */
 static char *get_admin_ssh_folder(Error **errp)
 {
     /* Allocate memory for the program data path */
     g_autofree char *programDataPath = NULL;
     char *authkeys_path = NULL;
     PWSTR pgDataW = NULL;
     g_autoptr(GError) gerr = NULL;

     /* Get the KnownFolderPath on the machine. */
     HRESULT folderResult =
         SHGetKnownFolderPath(&FOLDERID_ProgramData, 0, NULL, &pgDataW);
     if (folderResult != S_OK) {
         error_setg(errp, "Failed to retrieve ProgramData folder");
         return NULL;
     }

     /* Convert from a wide string back to a standard character string. */
     programDataPath = g_utf16_to_utf8(pgDataW, -1, NULL, NULL, &gerr);
     CoTaskMemFree(pgDataW);
     if (!programDataPath) {
         error_setg(errp,
                    "Failed converting ProgramData folder path to UTF-16 %s",
                    gerr->message);
         return NULL;
     }

     /* Build the path to the file. */
     authkeys_path = g_build_filename(programDataPath, "ssh", NULL);
     return authkeys_path;
 }

 /*
  * Gets the path to the SSH folder for the specified user. If the user is an
  * admin it returns the ssh folder located at %PROGRAMDATA%/ssh. If the user is
  * not an admin it returns %USERPROFILE%/.ssh
  *
  * parameters:
  * username -> Username to get the SSH folder for
  * isAdmin -> Whether the user is an admin or not
  * errp -> Error structure to set any errors that occur.
  * returns: path to the ssh folder as a string.
  */
 static char *get_ssh_folder(const char *username, const bool isAdmin,
                             Error **errp)
 {
     DWORD maxSize = MAX_PATH;
     g_autofree char *profilesDir = g_new0(char, maxSize);

     if (isAdmin) {
         return get_admin_ssh_folder(errp);
     }

     /* If not an Admin the SSH key is in the user directory. */
     /* Get the user profile directory on the machine. */
     BOOL ret = GetProfilesDirectory(profilesDir, &maxSize);
     if (!ret) {
         error_setg_win32(errp, GetLastError(),
                          "failed to retrieve profiles directory");
         return NULL;
     }

     /* Builds the filename */
     return g_build_filename(profilesDir, username, ".ssh", NULL);
 }

 /*
  * Creates an entry for the user so they can access the ssh folder in their
  * userprofile.
  *
  * parameters:
  * userInfo -> Information about the current user
  * pACL -> Pointer to an ACL structure
  * errp -> Error structure to set any errors that occur
  * returns -> 1 on success, 0 otherwise
  */
 static bool create_acl_user(PWindowsUserInfo userInfo, PACL *pACL, Error **errp)
 {
     const int aclSize = 1;
     PACL newACL = NULL;
     EXPLICIT_ACCESS eAccess[1];
     PSID userPSID = NULL;

     /* Get a pointer to the internal SID object in Windows */
     bool converted = ConvertStringSidToSid(userInfo->SSID, &userPSID);
     if (!converted) {
         error_setg_win32(errp, GetLastError(), "failed to retrieve user %s SID",
                          userInfo->username);
         goto error;
     }

     /* Set the permissions for the user. */
     eAccess[0].grfAccessPermissions = GENERIC_ALL;
     eAccess[0].grfAccessMode = SET_ACCESS;
     eAccess[0].grfInheritance = NO_INHERITANCE;
     eAccess[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
     eAccess[0].Trustee.TrusteeType = TRUSTEE_IS_USER;
     eAccess[0].Trustee.ptstrName = (LPTSTR)userPSID;

     /* Set the ACL entries */
     DWORD setResult;

     /*
      * If we are given a pointer that is already initialized, then we can merge
      * the existing entries instead of overwriting them.
      */
     if (*pACL) {
         setResult = SetEntriesInAcl(aclSize, eAccess, *pACL, &newACL);
     } else {
         setResult = SetEntriesInAcl(aclSize, eAccess, NULL, &newACL);
     }

     if (setResult != ERROR_SUCCESS) {
         error_setg_win32(errp, GetLastError(),
                          "failed to set ACL entries for user %s %lu",
                          userInfo->username, setResult);
         goto error;
     }

     /* Free any old memory since we are going to overwrite the users pointer. */
     LocalFree(*pACL);
     *pACL = newACL;

     LocalFree(userPSID);
     return true;
 error:
     LocalFree(userPSID);
     return false;
 }

 /*
  * Creates a base ACL for both normal users and admins to share
  * pACL -> Pointer to an ACL structure
  * errp -> Error structure to set any errors that occur
  * returns: 1 on success, 0 otherwise
  */
 static bool create_acl_base(PACL *pACL, Error **errp)
 {
     PSID adminGroupPSID = NULL;
     PSID systemPSID = NULL;

     const int aclSize = 2;
     EXPLICIT_ACCESS eAccess[2];

     /* Create an entry for the system user. */
     const char *systemSID = LOCAL_SYSTEM_SID;
     bool converted = ConvertStringSidToSid(systemSID, &systemPSID);
     if (!converted) {
         error_setg_win32(errp, GetLastError(), "failed to retrieve system SID");
         goto error;
     }

     /* set permissions for system user */
     eAccess[0].grfAccessPermissions = GENERIC_ALL;
     eAccess[0].grfAccessMode = SET_ACCESS;
     eAccess[0].grfInheritance = NO_INHERITANCE;
     eAccess[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
     eAccess[0].Trustee.TrusteeType = TRUSTEE_IS_USER;
     eAccess[0].Trustee.ptstrName = (LPTSTR)systemPSID;

     /* Create an entry for the admin user. */
     const char *adminSID = ADMIN_SID;
     converted = ConvertStringSidToSid(adminSID, &adminGroupPSID);
     if (!converted) {
         error_setg_win32(errp, GetLastError(), "failed to retrieve Admin SID");
         goto error;
     }

     /* Set permissions for admin group. */
     eAccess[1].grfAccessPermissions = GENERIC_ALL;
     eAccess[1].grfAccessMode = SET_ACCESS;
     eAccess[1].grfInheritance = NO_INHERITANCE;
     eAccess[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
     eAccess[1].Trustee.TrusteeType = TRUSTEE_IS_GROUP;
     eAccess[1].Trustee.ptstrName = (LPTSTR)adminGroupPSID;

     /* Put the entries in an ACL object. */
     PACL pNewACL = NULL;
     DWORD setResult;

     /*
      *If we are given a pointer that is already initialized, then we can merge
      *the existing entries instead of overwriting them.
      */
     if (*pACL) {
         setResult = SetEntriesInAcl(aclSize, eAccess, *pACL, &pNewACL);
     } else {
         setResult = SetEntriesInAcl(aclSize, eAccess, NULL, &pNewACL);
     }

     if (setResult != ERROR_SUCCESS) {
         error_setg_win32(errp, GetLastError(),
                          "failed to set base ACL entries for system user and "
                          "admin group %lu",
                          setResult);
         goto error;
     }

     LocalFree(adminGroupPSID);
     LocalFree(systemPSID);

     /* Free any old memory since we are going to overwrite the users pointer. */
     LocalFree(*pACL);

     *pACL = pNewACL;

     return true;

 error:
     LocalFree(adminGroupPSID);
     LocalFree(systemPSID);
     return false;
 }

 /*
  * Sets the access control on the authorized_keys file and any ssh folders that
  * need to be created. For administrators the required permissions on the
  * file/folders are that only administrators and the LocalSystem account can
  * access the folders. For normal user accounts only the specified user,
  * LocalSystem and Administrators can have access to the key.
  *
  * parameters:
  * userInfo -> pointer to structure that contains information about the user
  * PACL -> pointer to an access control structure that will be set upon
  * successful completion of the function.
  * errp -> error structure that will be set upon error.
  * returns: 1 upon success 0 upon failure.
  */
 static bool create_acl(PWindowsUserInfo userInfo, PACL *pACL, Error **errp)
 {
     /*
      * Creates a base ACL that both admins and users will share
      * This adds the Administrators group and the SYSTEM group
      */
     if (!create_acl_base(pACL, errp)) {
         return false;
     }

     /*
      * If the user is not an admin give the user creating the key permission to
      * access the file.
      */
     if (!userInfo->isAdmin) {
         if (!create_acl_user(userInfo, pACL, errp)) {
             return false;
         }

         return true;
     }

     return true;
 }
 /*
  * Create the SSH directory for the user and d sets appropriate permissions.
  * In general the directory will be %PROGRAMDATA%/ssh if the user is an admin.
  * %USERPOFILE%/.ssh if not an admin
  *
  * parameters:
  * userInfo -> Contains information about the user
  * errp -> Structure that will contain errors if the function fails.
  * returns: zero upon failure, 1 upon success
  */
 static bool create_ssh_directory(WindowsUserInfo *userInfo, Error **errp)
 {
     PACL pNewACL = NULL;
     g_autofree PSECURITY_DESCRIPTOR pSD = NULL;

     /* Gets the appropriate ACL for the user */
     if (!create_acl(userInfo, &pNewACL, errp)) {
         goto error;
     }

     /* Allocate memory for a security descriptor */
     pSD = g_malloc(SECURITY_DESCRIPTOR_MIN_LENGTH);
     if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION)) {
         error_setg_win32(errp, GetLastError(),
                          "Failed to initialize security descriptor");
         goto error;
     }

     /* Associate the security descriptor with the ACL permissions. */
     if (!SetSecurityDescriptorDacl(pSD, TRUE, pNewACL, FALSE)) {
         error_setg_win32(errp, GetLastError(),
                          "Failed to set security descriptor ACL");
         goto error;
     }

     /* Set the security attributes on the folder */
     SECURITY_ATTRIBUTES sAttr;
     sAttr.bInheritHandle = FALSE;
     sAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
     sAttr.lpSecurityDescriptor = pSD;

     /* Create the directory with the created permissions */
     BOOL created = CreateDirectory(userInfo->sshDirectory, &sAttr);
     if (!created) {
         error_setg_win32(errp, GetLastError(), "failed to create directory %s",
                          userInfo->sshDirectory);
         goto error;
     }

     /* Free memory */
     LocalFree(pNewACL);
     return true;
 error:
     LocalFree(pNewACL);
     return false;
 }

 /*
  * Sets permissions on the authorized_key_file that is created.
  *
  * parameters: userInfo -> Information about the user
  * errp -> error structure that will contain errors upon failure
  * returns: 1 upon success, zero upon failure.
  */
 static bool set_file_permissions(PWindowsUserInfo userInfo, Error **errp)
 {
     PACL pACL = NULL;
     PSID userPSID = NULL;

     /* Creates the access control structure */
     if (!create_acl(userInfo, &pACL, errp)) {
         goto error;
     }

     /* Get the PSID structure for the user based off the string SID. */
     bool converted = ConvertStringSidToSid(userInfo->SSID, &userPSID);
     if (!converted) {
         error_setg_win32(errp, GetLastError(), "failed to retrieve user %s SID",
                          userInfo->username);
         goto error;
     }

     /* Prevents permissions from being inherited and use the DACL provided. */
     const SE_OBJECT_TYPE securityBitFlags =
         DACL_SECURITY_INFORMATION | PROTECTED_DACL_SECURITY_INFORMATION;

     /* Set the ACL on the file. */
     if (SetNamedSecurityInfo(userInfo->authorizedKeyFile, SE_FILE_OBJECT,
                              securityBitFlags, userPSID, NULL, pACL,
                              NULL) != ERROR_SUCCESS) {
         error_setg_win32(errp, GetLastError(),
                          "failed to set file security for file %s",
                          userInfo->authorizedKeyFile);
         goto error;
     }

     LocalFree(pACL);
     LocalFree(userPSID);
     return true;

 error:
     LocalFree(pACL);
     LocalFree(userPSID);

     return false;
 }

 /*
  * Writes the specified keys to the authenticated keys file.
  * parameters:
  * userInfo: Information about the user we are writing the authkeys file to.
  * authkeys: Array of keys to write to disk
  * errp: Error structure that will contain any errors if they occur.
  * returns: 1 if successful, 0 otherwise.
  */
 static bool write_authkeys(WindowsUserInfo *userInfo, GStrv authkeys,
                            Error **errp)
 {
     g_autofree char *contents = NULL;
     g_autoptr(GError) err = NULL;

     contents = g_strjoinv("\n", authkeys);

     if (!g_file_set_contents(userInfo->authorizedKeyFile, contents, -1, &err)) {
         error_setg(errp, "failed to write to '%s': %s",
                    userInfo->authorizedKeyFile, err->message);
         return false;
     }

     if (!set_file_permissions(userInfo, errp)) {
         return false;
     }

     return true;
 }

 /*
  * Retrieves information about a Windows user by their username
  *
  * parameters:
  * userInfo -> Double pointer to a WindowsUserInfo structure. Upon success, it
  * will be allocated with information about the user and need to be freed.
  * username -> Name of the user to lookup.
  * errp -> Contains any errors that occur.
  * returns: 1 upon success, 0 upon failure.
  */
 static bool get_user_info(PWindowsUserInfo *userInfo, const char *username,
                           Error **errp)
 {
     DWORD infoLevel = 4;
     LPUSER_INFO_4 uBuf = NULL;
     g_autofree wchar_t *wideUserName = NULL;
     g_autoptr(GError) gerr = NULL;
     PSID psid = NULL;

     /*
      * Converts a string to a Windows wide string since the GetNetUserInfo
      * function requires it.
      */
     wideUserName = g_utf8_to_utf16(username, -1, NULL, NULL, &gerr);
     if (!wideUserName) {
         goto error;
     }

     /* allocate data */
     PWindowsUserInfo uData = g_new0(WindowsUserInfo, 1);

     /* Set pointer so it can be cleaned up by the callee, even upon error. */
     *userInfo = uData;

     /* Find the information */
     NET_API_STATUS result =
         NetUserGetInfo(NULL, wideUserName, infoLevel, (LPBYTE *)&uBuf);
     if (result != NERR_Success) {
         /* Give a friendlier error message if the user was not found. */
         if (result == NERR_UserNotFound) {
             error_setg(errp, "User %s was not found", username);
             goto error;
         }

         error_setg(errp,
                    "Received unexpected error when asking for user info: Error "
                    "Code %lu",
                    result);
         goto error;
     }

     /* Get information from the buffer returned by NetUserGetInfo. */
     uData->username = g_strdup(username);
     uData->isAdmin = uBuf->usri4_priv == USER_PRIV_ADMIN;
     psid = uBuf->usri4_user_sid;

     char *sidStr = NULL;

     /*
      * We store the string representation of the SID not SID structure in
      * memory. Callees wanting to use the SID structure should call
      * ConvertStringSidToSID.
      */
     if (!ConvertSidToStringSid(psid, &sidStr)) {
         error_setg_win32(errp, GetLastError(),
                          "failed to get SID string for user %s", username);
         goto error;
     }

     /* Store the SSID */
     uData->SSID = sidStr;

     /* Get the SSH folder for the user. */
     char *sshFolder = get_ssh_folder(username, uData->isAdmin, errp);
     if (sshFolder == NULL) {
         goto error;
     }

     /* Get the authorized key file path */
     const char *authorizedKeyFile =
         uData->isAdmin ? AUTHORIZED_KEY_FILE_ADMIN : AUTHORIZED_KEY_FILE;
     char *authorizedKeyPath =
         g_build_filename(sshFolder, authorizedKeyFile, NULL);
     uData->sshDirectory = sshFolder;
     uData->authorizedKeyFile = authorizedKeyPath;

     /* Free */
     NetApiBufferFree(uBuf);
     return true;
 error:
     if (uBuf) {
         NetApiBufferFree(uBuf);
     }

     return false;
 }

 /*
  * Gets the list of authorized keys for a user.
  *
  * parameters:
  * username -> Username to retrieve the keys for.
  * errp -> Error structure that will display any errors through QMP.
  * returns: List of keys associated with the user.
  */
 GuestAuthorizedKeys *qmp_guest_ssh_get_authorized_keys(const char *username,
                                                        Error **errp)
 {
     GuestAuthorizedKeys *keys = NULL;
     g_auto(GStrv) authKeys = NULL;
     g_autoptr(GuestAuthorizedKeys) ret = NULL;
     g_auto(PWindowsUserInfo) userInfo = NULL;

     /* Gets user information */
     if (!get_user_info(&userInfo, username, errp)) {
         return NULL;
     }

     /* Reads authkeys for the user */
     authKeys = read_authkeys(userInfo->authorizedKeyFile, errp);
     if (authKeys == NULL) {
         return NULL;
     }

     /* Set the GuestAuthorizedKey struct with keys from the file */
     ret = g_new0(GuestAuthorizedKeys, 1);
     for (int i = 0; authKeys[i] != NULL; i++) {
         g_strstrip(authKeys[i]);
         if (!authKeys[i][0] || authKeys[i][0] == '#') {
             continue;
         }

         QAPI_LIST_PREPEND(ret->keys, g_strdup(authKeys[i]));
     }

     /*
      * Steal the pointer because it is up for the callee to deallocate the
      * memory.
      */
     keys = g_steal_pointer(&ret);
     return keys;
 }

 /*
  * Adds an ssh key for a user.
  *
  * parameters:
  * username -> User to add the SSH key to
  * strList -> Array of keys to add to the list
  * has_reset -> Whether the keys have been reset
  * reset -> Boolean to reset the keys (If this is set the existing list will be
  * cleared) and the other key reset. errp -> Pointer to an error structure that
  * will get returned over QMP if anything goes wrong.
  */
 void qmp_guest_ssh_add_authorized_keys(const char *username, strList *keys,
                                        bool has_reset, bool reset, Error **errp)
 {
     g_auto(PWindowsUserInfo) userInfo = NULL;
     g_auto(GStrv) authkeys = NULL;
     strList *k;
     size_t nkeys, nauthkeys;

     /* Make sure the keys given are valid */
     if (!check_openssh_pub_keys(keys, &nkeys, errp)) {
         return;
     }

     /* Gets user information */
     if (!get_user_info(&userInfo, username, errp)) {
         return;
     }

     /* Determine whether we should reset the keys */
     reset = has_reset && reset;
     if (!reset) {
         /* Read existing keys into memory */
         authkeys = read_authkeys(userInfo->authorizedKeyFile, NULL);
     }

     /* Check that the SSH key directory exists for the user. */
     if (!g_file_test(userInfo->sshDirectory, G_FILE_TEST_IS_DIR)) {
         BOOL success = create_ssh_directory(userInfo, errp);
         if (!success) {
             return;
         }
     }

     /* Reallocates the buffer to fit the new keys. */
     nauthkeys = authkeys ? g_strv_length(authkeys) : 0;
     authkeys = g_realloc_n(authkeys, nauthkeys + nkeys + 1, sizeof(char *));

     /* zero out the memory for the reallocated buffer */
     memset(authkeys + nauthkeys, 0, (nkeys + 1) * sizeof(char *));

     /* Adds the keys */
     for (k = keys; k != NULL; k = k->next) {
         /* Check that the key doesn't already exist */
         if (g_strv_contains((const gchar *const *)authkeys, k->value)) {
             continue;
         }

         authkeys[nauthkeys++] = g_strdup(k->value);
     }

     /* Write the authkeys to the file. */
     write_authkeys(userInfo, authkeys, errp);
 }

 /*
  * Removes an SSH key for a user
  *
  * parameters:
  * username -> Username to remove the key from
  * strList -> List of strings to remove
  * errp -> Contains any errors that occur.
  */
 void qmp_guest_ssh_remove_authorized_keys(const char *username, strList *keys,
                                           Error **errp)
 {
     g_auto(PWindowsUserInfo) userInfo = NULL;
     g_autofree struct passwd *p = NULL;
     g_autofree GStrv new_keys = NULL; /* do not own the strings */
     g_auto(GStrv) authkeys = NULL;
     GStrv a;
     size_t nkeys = 0;

     /* Validates the keys passed in by the user */
     if (!check_openssh_pub_keys(keys, NULL, errp)) {
         return;
     }

     /* Gets user information */
     if (!get_user_info(&userInfo, username, errp)) {
         return;
     }

     /* Reads the authkeys for the user */
     authkeys = read_authkeys(userInfo->authorizedKeyFile, errp);
     if (authkeys == NULL) {
         return;
     }

     /* Create a new buffer to hold the keys */
     new_keys = g_new0(char *, g_strv_length(authkeys) + 1);
     for (a = authkeys; *a != NULL; a++) {
         strList *k;

         /* Filters out keys that are equal to ones the user specified. */
         for (k = keys; k != NULL; k = k->next) {
             if (g_str_equal(k->value, *a)) {
                 break;
             }
         }

         if (k != NULL) {
             continue;
         }

         new_keys[nkeys++] = *a;
     }

     /* Write the new authkeys to the file. */
     write_authkeys(userInfo, new_keys, errp);
 }
	/*
	* QEMU Guest Agent win32-specific command implementations for SSH keys.
	* The implementation is opinionated and expects the SSH implementation to
	* be OpenSSH.
	*
	* Copyright Schweitzer Engineering Laboratories. 2024
	*
	* Authors:
	* Aidan Leuck <aidan_leuck@selinc.com>
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or later.
	* See the COPYING file in the top-level directory.
	*/

	#include "qemu/osdep.h"
	#include <aclapi.h>
	#include <qga-qapi-types.h>

	#include "commands-common-ssh.h"
	#include "commands-windows-ssh.h"
	#include "guest-agent-core.h"
	#include "limits.h"
	#include "lmaccess.h"
	#include "lmapibuf.h"
	#include "lmerr.h"
	#include "qapi/error.h"

	#include "qga-qapi-commands.h"
	#include "sddl.h"
	#include "shlobj.h"
	#include "userenv.h"

	#define AUTHORIZED_KEY_FILE "authorized_keys"
	#define AUTHORIZED_KEY_FILE_ADMIN "administrators_authorized_keys"
	#define LOCAL_SYSTEM_SID "S-1-5-18"
	#define ADMIN_SID "S-1-5-32-544"

	/*
	* Frees userInfo structure. This implements the g_auto cleanup
	* for the structure.
	*/
	void free_userInfo(PWindowsUserInfo info)
	{
	g_free(info->sshDirectory);
	g_free(info->authorizedKeyFile);
	LocalFree(info->SSID);
	g_free(info->username);
	g_free(info);
	}

	/*
	* Gets the admin SSH folder for OpenSSH. OpenSSH does not store
	* the authorized_key file in the users home directory for security reasons and
	* instead stores it at %PROGRAMDATA%/ssh. This function returns the path to
	* that directory on the users machine
	*
	* parameters:
	* errp -> error structure to set when an error occurs
	* returns: The path to the ssh folder in %PROGRAMDATA% or NULL if an error
	* occurred.
	*/
	static char get_admin_ssh_folder(Error *errp)
	{
	/* Allocate memory for the program data path */
	g_autofree char *programDataPath = NULL;
	char *authkeys_path = NULL;
	PWSTR pgDataW = NULL;
	g_autoptr(GError) gerr = NULL;

	/* Get the KnownFolderPath on the machine. */
	HRESULT folderResult =
	SHGetKnownFolderPath(&FOLDERID_ProgramData, 0, NULL, &pgDataW);
	if (folderResult != S_OK) {
	error_setg(errp, "Failed to retrieve ProgramData folder");
	return NULL;
	}

	/* Convert from a wide string back to a standard character string. */
	programDataPath = g_utf16_to_utf8(pgDataW, -1, NULL, NULL, &gerr);
	CoTaskMemFree(pgDataW);
	if (!programDataPath) {
	error_setg(errp,
	"Failed converting ProgramData folder path to UTF-16 %s",
	gerr->message);
	return NULL;
	}

	/* Build the path to the file. */
	authkeys_path = g_build_filename(programDataPath, "ssh", NULL);
	return authkeys_path;
	}

	/*
	* Gets the path to the SSH folder for the specified user. If the user is an
	* admin it returns the ssh folder located at %PROGRAMDATA%/ssh. If the user is
	* not an admin it returns %USERPROFILE%/.ssh
	*
	* parameters:
	* username -> Username to get the SSH folder for
	* isAdmin -> Whether the user is an admin or not
	* errp -> Error structure to set any errors that occur.
	* returns: path to the ssh folder as a string.
	*/
	static char get_ssh_folder(const char username, const bool isAdmin,
	Error **errp)
	{
	DWORD maxSize = MAX_PATH;
	g_autofree char *profilesDir = g_new0(char, maxSize);

	if (isAdmin) {
	return get_admin_ssh_folder(errp);
	}

	/* If not an Admin the SSH key is in the user directory. */
	/* Get the user profile directory on the machine. */
	BOOL ret = GetProfilesDirectory(profilesDir, &maxSize);
	if (!ret) {
	error_setg_win32(errp, GetLastError(),
	"failed to retrieve profiles directory");
	return NULL;
	}

	/* Builds the filename */
	return g_build_filename(profilesDir, username, ".ssh", NULL);
	}

	/*
	* Creates an entry for the user so they can access the ssh folder in their
	* userprofile.
	*
	* parameters:
	* userInfo -> Information about the current user
	* pACL -> Pointer to an ACL structure
	* errp -> Error structure to set any errors that occur
	* returns -> 1 on success, 0 otherwise
	*/
	static bool create_acl_user(PWindowsUserInfo userInfo, PACL pACL, Error *errp)
	{
	const int aclSize = 1;
	PACL newACL = NULL;
	EXPLICIT_ACCESS eAccess[1];
	PSID userPSID = NULL;

	/* Get a pointer to the internal SID object in Windows */
	bool converted = ConvertStringSidToSid(userInfo->SSID, &userPSID);
	if (!converted) {
	error_setg_win32(errp, GetLastError(), "failed to retrieve user %s SID",
	userInfo->username);
	goto error;
	}

	/* Set the permissions for the user. */
	eAccess[0].grfAccessPermissions = GENERIC_ALL;
	eAccess[0].grfAccessMode = SET_ACCESS;
	eAccess[0].grfInheritance = NO_INHERITANCE;
	eAccess[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
	eAccess[0].Trustee.TrusteeType = TRUSTEE_IS_USER;
	eAccess[0].Trustee.ptstrName = (LPTSTR)userPSID;

	/* Set the ACL entries */
	DWORD setResult;

	/*
	* If we are given a pointer that is already initialized, then we can merge
	* the existing entries instead of overwriting them.
	*/
	if (*pACL) {
	setResult = SetEntriesInAcl(aclSize, eAccess, *pACL, &newACL);
	} else {
	setResult = SetEntriesInAcl(aclSize, eAccess, NULL, &newACL);
	}

	if (setResult != ERROR_SUCCESS) {
	error_setg_win32(errp, GetLastError(),
	"failed to set ACL entries for user %s %lu",
	userInfo->username, setResult);
	goto error;
	}

	/* Free any old memory since we are going to overwrite the users pointer. */
	LocalFree(*pACL);
	*pACL = newACL;

	LocalFree(userPSID);
	return true;
	error:
	LocalFree(userPSID);
	return false;
	}

	/*
	* Creates a base ACL for both normal users and admins to share
	* pACL -> Pointer to an ACL structure
	* errp -> Error structure to set any errors that occur
	* returns: 1 on success, 0 otherwise
	*/
	static bool create_acl_base(PACL pACL, Error *errp)
	{
	PSID adminGroupPSID = NULL;
	PSID systemPSID = NULL;

	const int aclSize = 2;
	EXPLICIT_ACCESS eAccess[2];

	/* Create an entry for the system user. */
	const char *systemSID = LOCAL_SYSTEM_SID;
	bool converted = ConvertStringSidToSid(systemSID, &systemPSID);
	if (!converted) {
	error_setg_win32(errp, GetLastError(), "failed to retrieve system SID");
	goto error;
	}

	/* set permissions for system user */
	eAccess[0].grfAccessPermissions = GENERIC_ALL;
	eAccess[0].grfAccessMode = SET_ACCESS;
	eAccess[0].grfInheritance = NO_INHERITANCE;
	eAccess[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
	eAccess[0].Trustee.TrusteeType = TRUSTEE_IS_USER;
	eAccess[0].Trustee.ptstrName = (LPTSTR)systemPSID;

	/* Create an entry for the admin user. */
	const char *adminSID = ADMIN_SID;
	converted = ConvertStringSidToSid(adminSID, &adminGroupPSID);
	if (!converted) {
	error_setg_win32(errp, GetLastError(), "failed to retrieve Admin SID");
	goto error;
	}

	/* Set permissions for admin group. */
	eAccess[1].grfAccessPermissions = GENERIC_ALL;
	eAccess[1].grfAccessMode = SET_ACCESS;
	eAccess[1].grfInheritance = NO_INHERITANCE;
	eAccess[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
	eAccess[1].Trustee.TrusteeType = TRUSTEE_IS_GROUP;
	eAccess[1].Trustee.ptstrName = (LPTSTR)adminGroupPSID;

	/* Put the entries in an ACL object. */
	PACL pNewACL = NULL;
	DWORD setResult;

	/*
	*If we are given a pointer that is already initialized, then we can merge
	*the existing entries instead of overwriting them.
	*/
	if (*pACL) {
	setResult = SetEntriesInAcl(aclSize, eAccess, *pACL, &pNewACL);
	} else {
	setResult = SetEntriesInAcl(aclSize, eAccess, NULL, &pNewACL);
	}

	if (setResult != ERROR_SUCCESS) {
	error_setg_win32(errp, GetLastError(),
	"failed to set base ACL entries for system user and "
	"admin group %lu",
	setResult);
	goto error;
	}

	LocalFree(adminGroupPSID);
	LocalFree(systemPSID);

	/* Free any old memory since we are going to overwrite the users pointer. */
	LocalFree(*pACL);

	*pACL = pNewACL;

	return true;

	error:
	LocalFree(adminGroupPSID);
	LocalFree(systemPSID);
	return false;
	}

	/*
	* Sets the access control on the authorized_keys file and any ssh folders that
	* need to be created. For administrators the required permissions on the
	* file/folders are that only administrators and the LocalSystem account can
	* access the folders. For normal user accounts only the specified user,
	* LocalSystem and Administrators can have access to the key.
	*
	* parameters:
	* userInfo -> pointer to structure that contains information about the user
	* PACL -> pointer to an access control structure that will be set upon
	* successful completion of the function.
	* errp -> error structure that will be set upon error.
	* returns: 1 upon success 0 upon failure.
	*/
	static bool create_acl(PWindowsUserInfo userInfo, PACL pACL, Error *errp)
	{
	/*
	* Creates a base ACL that both admins and users will share
	* This adds the Administrators group and the SYSTEM group
	*/
	if (!create_acl_base(pACL, errp)) {
	return false;
	}

	/*
	* If the user is not an admin give the user creating the key permission to
	* access the file.
	*/
	if (!userInfo->isAdmin) {
	if (!create_acl_user(userInfo, pACL, errp)) {
	return false;
	}

	return true;
	}

	return true;
	}
	/*
	* Create the SSH directory for the user and d sets appropriate permissions.
	* In general the directory will be %PROGRAMDATA%/ssh if the user is an admin.
	* %USERPOFILE%/.ssh if not an admin
	*
	* parameters:
	* userInfo -> Contains information about the user
	* errp -> Structure that will contain errors if the function fails.
	* returns: zero upon failure, 1 upon success
	*/
	static bool create_ssh_directory(WindowsUserInfo userInfo, Error *errp)
	{
	PACL pNewACL = NULL;
	g_autofree PSECURITY_DESCRIPTOR pSD = NULL;

	/* Gets the appropriate ACL for the user */
	if (!create_acl(userInfo, &pNewACL, errp)) {
	goto error;
	}

	/* Allocate memory for a security descriptor */
	pSD = g_malloc(SECURITY_DESCRIPTOR_MIN_LENGTH);
	if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION)) {
	error_setg_win32(errp, GetLastError(),
	"Failed to initialize security descriptor");
	goto error;
	}

	/* Associate the security descriptor with the ACL permissions. */
	if (!SetSecurityDescriptorDacl(pSD, TRUE, pNewACL, FALSE)) {
	error_setg_win32(errp, GetLastError(),
	"Failed to set security descriptor ACL");
	goto error;
	}

	/* Set the security attributes on the folder */
	SECURITY_ATTRIBUTES sAttr;
	sAttr.bInheritHandle = FALSE;
	sAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
	sAttr.lpSecurityDescriptor = pSD;

	/* Create the directory with the created permissions */
	BOOL created = CreateDirectory(userInfo->sshDirectory, &sAttr);
	if (!created) {
	error_setg_win32(errp, GetLastError(), "failed to create directory %s",
	userInfo->sshDirectory);
	goto error;
	}

	/* Free memory */
	LocalFree(pNewACL);
	return true;
	error:
	LocalFree(pNewACL);
	return false;
	}

	/*
	* Sets permissions on the authorized_key_file that is created.
	*
	* parameters: userInfo -> Information about the user
	* errp -> error structure that will contain errors upon failure
	* returns: 1 upon success, zero upon failure.
	*/
	static bool set_file_permissions(PWindowsUserInfo userInfo, Error **errp)
	{
	PACL pACL = NULL;
	PSID userPSID = NULL;

	/* Creates the access control structure */
	if (!create_acl(userInfo, &pACL, errp)) {
	goto error;
	}

	/* Get the PSID structure for the user based off the string SID. */
	bool converted = ConvertStringSidToSid(userInfo->SSID, &userPSID);
	if (!converted) {
	error_setg_win32(errp, GetLastError(), "failed to retrieve user %s SID",
	userInfo->username);
	goto error;
	}

	/* Prevents permissions from being inherited and use the DACL provided. */
	const SE_OBJECT_TYPE securityBitFlags =
	DACL_SECURITY_INFORMATION \| PROTECTED_DACL_SECURITY_INFORMATION;

	/* Set the ACL on the file. */
	if (SetNamedSecurityInfo(userInfo->authorizedKeyFile, SE_FILE_OBJECT,
	securityBitFlags, userPSID, NULL, pACL,
	NULL) != ERROR_SUCCESS) {
	error_setg_win32(errp, GetLastError(),
	"failed to set file security for file %s",
	userInfo->authorizedKeyFile);
	goto error;
	}

	LocalFree(pACL);
	LocalFree(userPSID);
	return true;

	error:
	LocalFree(pACL);
	LocalFree(userPSID);

	return false;
	}

	/*
	* Writes the specified keys to the authenticated keys file.
	* parameters:
	* userInfo: Information about the user we are writing the authkeys file to.
	* authkeys: Array of keys to write to disk
	* errp: Error structure that will contain any errors if they occur.
	* returns: 1 if successful, 0 otherwise.
	*/
	static bool write_authkeys(WindowsUserInfo *userInfo, GStrv authkeys,
	Error **errp)
	{
	g_autofree char *contents = NULL;
	g_autoptr(GError) err = NULL;

	contents = g_strjoinv("\n", authkeys);

	if (!g_file_set_contents(userInfo->authorizedKeyFile, contents, -1, &err)) {
	error_setg(errp, "failed to write to '%s': %s",
	userInfo->authorizedKeyFile, err->message);
	return false;
	}

	if (!set_file_permissions(userInfo, errp)) {
	return false;
	}

	return true;
	}

	/*
	* Retrieves information about a Windows user by their username
	*
	* parameters:
	* userInfo -> Double pointer to a WindowsUserInfo structure. Upon success, it
	* will be allocated with information about the user and need to be freed.
	* username -> Name of the user to lookup.
	* errp -> Contains any errors that occur.
	* returns: 1 upon success, 0 upon failure.
	*/
	static bool get_user_info(PWindowsUserInfo userInfo, const char username,
	Error **errp)
	{
	DWORD infoLevel = 4;
	LPUSER_INFO_4 uBuf = NULL;
	g_autofree wchar_t *wideUserName = NULL;
	g_autoptr(GError) gerr = NULL;
	PSID psid = NULL;

	/*
	* Converts a string to a Windows wide string since the GetNetUserInfo
	* function requires it.
	*/
	wideUserName = g_utf8_to_utf16(username, -1, NULL, NULL, &gerr);
	if (!wideUserName) {
	goto error;
	}

	/* allocate data */
	PWindowsUserInfo uData = g_new0(WindowsUserInfo, 1);

	/* Set pointer so it can be cleaned up by the callee, even upon error. */
	*userInfo = uData;

	/* Find the information */
	NET_API_STATUS result =
	NetUserGetInfo(NULL, wideUserName, infoLevel, (LPBYTE *)&uBuf);
	if (result != NERR_Success) {
	/* Give a friendlier error message if the user was not found. */
	if (result == NERR_UserNotFound) {
	error_setg(errp, "User %s was not found", username);
	goto error;
	}

	error_setg(errp,
	"Received unexpected error when asking for user info: Error "
	"Code %lu",
	result);
	goto error;
	}

	/* Get information from the buffer returned by NetUserGetInfo. */
	uData->username = g_strdup(username);
	uData->isAdmin = uBuf->usri4_priv == USER_PRIV_ADMIN;
	psid = uBuf->usri4_user_sid;

	char *sidStr = NULL;

	/*
	* We store the string representation of the SID not SID structure in
	* memory. Callees wanting to use the SID structure should call
	* ConvertStringSidToSID.
	*/
	if (!ConvertSidToStringSid(psid, &sidStr)) {
	error_setg_win32(errp, GetLastError(),
	"failed to get SID string for user %s", username);
	goto error;
	}

	/* Store the SSID */
	uData->SSID = sidStr;

	/* Get the SSH folder for the user. */
	char *sshFolder = get_ssh_folder(username, uData->isAdmin, errp);
	if (sshFolder == NULL) {
	goto error;
	}

	/* Get the authorized key file path */
	const char *authorizedKeyFile =
	uData->isAdmin ? AUTHORIZED_KEY_FILE_ADMIN : AUTHORIZED_KEY_FILE;
	char *authorizedKeyPath =
	g_build_filename(sshFolder, authorizedKeyFile, NULL);
	uData->sshDirectory = sshFolder;
	uData->authorizedKeyFile = authorizedKeyPath;

	/* Free */
	NetApiBufferFree(uBuf);
	return true;
	error:
	if (uBuf) {
	NetApiBufferFree(uBuf);
	}

	return false;
	}

	/*
	* Gets the list of authorized keys for a user.
	*
	* parameters:
	* username -> Username to retrieve the keys for.
	* errp -> Error structure that will display any errors through QMP.
	* returns: List of keys associated with the user.
	*/
	GuestAuthorizedKeys qmp_guest_ssh_get_authorized_keys(const char username,
	Error **errp)
	{
	GuestAuthorizedKeys *keys = NULL;
	g_auto(GStrv) authKeys = NULL;
	g_autoptr(GuestAuthorizedKeys) ret = NULL;
	g_auto(PWindowsUserInfo) userInfo = NULL;

	/* Gets user information */
	if (!get_user_info(&userInfo, username, errp)) {
	return NULL;
	}

	/* Reads authkeys for the user */
	authKeys = read_authkeys(userInfo->authorizedKeyFile, errp);
	if (authKeys == NULL) {
	return NULL;
	}

	/* Set the GuestAuthorizedKey struct with keys from the file */
	ret = g_new0(GuestAuthorizedKeys, 1);
	for (int i = 0; authKeys[i] != NULL; i++) {
	g_strstrip(authKeys[i]);
	if (!authKeys[i][0] \|\| authKeys[i][0] == '#') {
	continue;
	}

	QAPI_LIST_PREPEND(ret->keys, g_strdup(authKeys[i]));
	}

	/*
	* Steal the pointer because it is up for the callee to deallocate the
	* memory.
	*/
	keys = g_steal_pointer(&ret);
	return keys;
	}

	/*
	* Adds an ssh key for a user.
	*
	* parameters:
	* username -> User to add the SSH key to
	* strList -> Array of keys to add to the list
	* has_reset -> Whether the keys have been reset
	* reset -> Boolean to reset the keys (If this is set the existing list will be
	* cleared) and the other key reset. errp -> Pointer to an error structure that
	* will get returned over QMP if anything goes wrong.
	*/
	void qmp_guest_ssh_add_authorized_keys(const char username, strList keys,
	bool has_reset, bool reset, Error **errp)
	{
	g_auto(PWindowsUserInfo) userInfo = NULL;
	g_auto(GStrv) authkeys = NULL;
	strList *k;
	size_t nkeys, nauthkeys;

	/* Make sure the keys given are valid */
	if (!check_openssh_pub_keys(keys, &nkeys, errp)) {
	return;
	}

	/* Gets user information */
	if (!get_user_info(&userInfo, username, errp)) {
	return;
	}

	/* Determine whether we should reset the keys */
	reset = has_reset && reset;
	if (!reset) {
	/* Read existing keys into memory */
	authkeys = read_authkeys(userInfo->authorizedKeyFile, NULL);
	}

	/* Check that the SSH key directory exists for the user. */
	if (!g_file_test(userInfo->sshDirectory, G_FILE_TEST_IS_DIR)) {
	BOOL success = create_ssh_directory(userInfo, errp);
	if (!success) {
	return;
	}
	}

	/* Reallocates the buffer to fit the new keys. */
	nauthkeys = authkeys ? g_strv_length(authkeys) : 0;
	authkeys = g_realloc_n(authkeys, nauthkeys + nkeys + 1, sizeof(char *));

	/* zero out the memory for the reallocated buffer */
	memset(authkeys + nauthkeys, 0, (nkeys + 1) * sizeof(char *));

	/* Adds the keys */
	for (k = keys; k != NULL; k = k->next) {
	/* Check that the key doesn't already exist */
	if (g_strv_contains((const gchar const )authkeys, k->value)) {
	continue;
	}

	authkeys[nauthkeys++] = g_strdup(k->value);
	}

	/* Write the authkeys to the file. */
	write_authkeys(userInfo, authkeys, errp);
	}

	/*
	* Removes an SSH key for a user
	*
	* parameters:
	* username -> Username to remove the key from
	* strList -> List of strings to remove
	* errp -> Contains any errors that occur.
	*/
	void qmp_guest_ssh_remove_authorized_keys(const char username, strList keys,
	Error **errp)
	{
	g_auto(PWindowsUserInfo) userInfo = NULL;
	g_autofree struct passwd *p = NULL;
	g_autofree GStrv new_keys = NULL; /* do not own the strings */
	g_auto(GStrv) authkeys = NULL;
	GStrv a;
	size_t nkeys = 0;

	/* Validates the keys passed in by the user */
	if (!check_openssh_pub_keys(keys, NULL, errp)) {
	return;
	}

	/* Gets user information */
	if (!get_user_info(&userInfo, username, errp)) {
	return;
	}

	/* Reads the authkeys for the user */
	authkeys = read_authkeys(userInfo->authorizedKeyFile, errp);
	if (authkeys == NULL) {
	return;
	}

	/* Create a new buffer to hold the keys */
	new_keys = g_new0(char *, g_strv_length(authkeys) + 1);
	for (a = authkeys; *a != NULL; a++) {
	strList *k;

	/* Filters out keys that are equal to ones the user specified. */
	for (k = keys; k != NULL; k = k->next) {
	if (g_str_equal(k->value, *a)) {
	break;
	}
	}

	if (k != NULL) {
	continue;
	}

	new_keys[nkeys++] = *a;
	}

	/* Write the new authkeys to the file. */
	write_authkeys(userInfo, new_keys, errp);
	}