[v2,1/2] Implement SSH commands in QEMU GA for Windows

From: aidaleuc <aidan_leuck@selinc.com>

Signed-off-by: aidaleuc <aidan_leuck@selinc.com>
---
 qga/commands-windows-ssh.c | 848 +++++++++++++++++++++++++++++++++++++
 qga/commands-windows-ssh.h |  26 ++
 qga/meson.build            |   9 +-
 qga/qapi-schema.json       |  22 +-
 4 files changed, 892 insertions(+), 13 deletions(-)
 create mode 100644 qga/commands-windows-ssh.c
 create mode 100644 qga/commands-windows-ssh.h

On Thu, Mar 21, 2024 at 04:07:24PM +0000, aidan_leuck@selinc.com wrote:
> From: aidaleuc <aidan_leuck@selinc.com>
> 
> Signed-off-by: aidaleuc <aidan_leuck@selinc.com>
> ---
>  qga/commands-windows-ssh.c | 848 +++++++++++++++++++++++++++++++++++++
>  qga/commands-windows-ssh.h |  26 ++
>  qga/meson.build            |   9 +-
>  qga/qapi-schema.json       |  22 +-
>  4 files changed, 892 insertions(+), 13 deletions(-)
>  create mode 100644 qga/commands-windows-ssh.c
>  create mode 100644 qga/commands-windows-ssh.h
> 
> diff --git a/qga/commands-windows-ssh.c b/qga/commands-windows-ssh.c
> new file mode 100644
> index 0000000000..566266f465
> --- /dev/null
> +++ b/qga/commands-windows-ssh.c
> @@ -0,0 +1,848 @@


> +static char *get_admin_ssh_folder(Error **errp)
> +{
> +  // Allocate memory for the program data path

Please use C /* ... */  comments, not C++ comment style

> +  g_autofree char *programDataPath = NULL;
> +  char *authkeys_path = NULL;
> +  PWSTR pgDataW;

Nothing initializes pgDataW here.

> +  GError *gerr = NULL;

Declare that 'g_autoptr(GError) gerr = NULL', avoiding the
need for manual g_Error_Free calls.

> +
> +  // Get the KnownFolderPath on the machine.
> +  HRESULT folderResult =
> +      SHGetKnownFolderPath(&FOLDERID_ProgramData, 0, NULL, &pgDataW);
> +  if (folderResult != S_OK) {

This method is the initializer for 'pgDataW', but in this
error scenario, is there any guarantee that 'pgDataW'
will actually have been initialized ? We're about to jump
to an 'error' label that will try to free this.

> +    error_setg(errp, "Failed to retrieve ProgramData folder");
> +    goto error;

QEMU indent standard is 4 spaces, rather than 2 spaces. Applies
throughout this patch.

> +  }
> +
> +  // Convert from a wide string back to a standard character string.
> +  programDataPath = g_utf16_to_utf8(pgDataW, -1, NULL, NULL, &gerr);

If you put the 'CoTaskMemFree(pgDataW)' call here

> +  if (!programDataPath) {

and call error_setg(...., gerr->mssage); here

we can avoid the need for any 'error:' cleanup block at all. All
places can just 'return NULL' immediately.

> +    goto error;
> +  }
> +
> +  // Build the path to the file.
> +  authkeys_path = g_build_filename(programDataPath, "ssh", NULL);
> +  CoTaskMemFree(pgDataW);
> +  return authkeys_path;
> +
> +error:
> +  CoTaskMemFree(pgDataW);

...before we access pgDataW here potentially uninitialized.

> +  
> +  if (gerr) {
> +    error_setg(errp,"Failed to convert program data path from wide string to standard utf 8 string. %s", gerr->message);
> +    g_error_free(gerr);
> +  }
> +
> +  return NULL;
> +}
> +
> +/*
> + * 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)
> +{
> +  if (isAdmin) {
> +    return get_admin_ssh_folder(errp);
> +  }
> +
> +  // If not an Admin the SSH key is in the user directory.
> +  DWORD maxSize = MAX_PATH;

QEMU preference is for all variables to be declared at the start of
the code scope block. This is especially important when using
g_autofree at the same time as 'goto', as if a goto jumps over
a variable declaration, it will remain uninitialized.

> +  g_autofree char* profilesDir = g_malloc(maxSize);

Use 'char *' rather than 'char*', and use g_new0 to guarantee the
memory is initialized.

> +
> +  // 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 everyone group. This is used when the user is an Administrator
> + * This is consistent with the folder permissions that OpenSSH creates when it
> + * is installed. Anyone can read the file, but only Administrators and SYSTEM can
> + * modify the file.
> + *
> + * 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_admin(PWindowsUserInfo userInfo, PACL *pACL,
> +                             Error **errp)
> +{
> +  PSID everyonePSID = NULL;
> +
> +  const int aclSize = 1;
> +  EXPLICIT_ACCESS eAccess[1];
> +
> +  // Zero out memory for the explicit access array
> +  ZeroMemory(&eAccess, aclSize * sizeof(EXPLICIT_ACCESS));

Calling ZeroMemory is redundant, just let the compiler do this

 EXPLICIT_ACCESS eAccess[1] = {};

> +
> +  // Create an entry for everyone (so they can at least read the folder).
> +  // This is consistent with other folders located in %PROGRAMDATA%
> +  bool converted = ConvertStringSidToSid(WORLD_SID, &everyonePSID);
> +  if (!converted) {
> +    error_setg_win32(errp, GetLastError(), "failed to retrieve Admin SID");
> +    goto error;
> +  }
> +
> +  // Set permissions for everyone group (they can only read the files)
> +  eAccess[0].grfAccessPermissions = GENERIC_READ;
> +  eAccess[0].grfAccessMode = SET_ACCESS;
> +  eAccess[0].grfInheritance = NO_INHERITANCE;
> +  eAccess[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
> +  eAccess[0].Trustee.TrusteeType = TRUSTEE_IS_GROUP;
> +  eAccess[0].Trustee.ptstrName = (LPTSTR)everyonePSID;
> +
> +  // 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 ACL entries for admin user %s %lu",
> +                     userInfo->username, setResult);
> +    goto error;
> +  }
> +
> +  LocalFree(everyonePSID);
> +
> +  // Free the old memory since we are going to overwrite the users
> +  // pointer
> +  LocalFree(*pACL);
> +  *pACL = pNewACL;
> +
> +  return true;
> +
> +error:
> +  LocalFree(everyonePSID);
> +  return false;
> +}
> +
> +/*
> + * 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;
> +
> +  // Zero out memory for the explicit access array
> +  ZeroMemory(&eAccess, aclSize * sizeof(EXPLICIT_ACCESS));
> +
> +  // 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];
> +
> +  // Zero out memory for the explicit access array
> +  ZeroMemory(&eAccess, aclSize * sizeof(EXPLICIT_ACCESS));
> +
> +  // 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;
> +  }
> +
> +  // If the user is an admin allow everyone to read the keys
> +  if (!create_acl_admin(userInfo, pACL, errp)) {
> +    return false;
> +  }
> +
> +  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 approparite 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;
> +
> +  // 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;
> +  }
> +
> +  // Set the ACL on the file.
> +  if (SetNamedSecurityInfo(userInfo->authorizedKeyFile, SE_FILE_OBJECT,
> +                           DACL_SECURITY_INFORMATION, 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;
> +  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_malloc(sizeof(WindowsUserInfo));
> +
> +  // Set pointer so it can be cleaned up by the calle, 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);
> +  }
> +  if (gerr) {
> +    error_setg(errp, "Failed to convert username %s to wide string. %s",
> +               username, gerr->message);
> +    g_error_free(gerr);
> +  }
> +
> +  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 authekys 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) {
> +    // If we are not resetting the keys, read the 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);
> +}
> diff --git a/qga/commands-windows-ssh.h b/qga/commands-windows-ssh.h
> new file mode 100644
> index 0000000000..7d68a1bcef
> --- /dev/null
> +++ b/qga/commands-windows-ssh.h
> @@ -0,0 +1,26 @@
> +/*
> + * Header file for commands-windows-ssh.c
> + *
> + * 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 <glib/gstrfuncs.h>
> +#include <stdbool.h>
> +typedef struct WindowsUserInfo {
> +  char *sshDirectory;
> +  char *authorizedKeyFile;
> +  char *username;
> +  char *SSID;
> +  bool isAdmin;
> +} WindowsUserInfo;
> +
> +typedef WindowsUserInfo *PWindowsUserInfo;
> +
> +void free_userInfo(PWindowsUserInfo info);
> +G_DEFINE_AUTO_CLEANUP_FREE_FUNC(PWindowsUserInfo, free_userInfo, NULL);

> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
> index 9554b566a7..ffa7eb4082 100644
> --- a/qga/qapi-schema.json
> +++ b/qga/qapi-schema.json
> @@ -1599,8 +1599,10 @@
>  # Since: 5.2
>  ##
>  { 'command': 'guest-ssh-add-authorized-keys',
> -  'data': { 'username': 'str', 'keys': ['str'], '*reset': 'bool' },
> -  'if': 'CONFIG_POSIX' }
> +  'data': { 'username': 'str', 'keys': ['str'
> +    ], '*reset': 'bool'
> +  }

Don't insert these two extra linebreaks, it is already short enough as is.


> +}
>  
>  ##
>  # @guest-ssh-remove-authorized-keys:
> @@ -1617,8 +1619,10 @@
>  # Since: 5.2
>  ##
>  { 'command': 'guest-ssh-remove-authorized-keys',
> -  'data': { 'username': 'str', 'keys': ['str'] },
> -  'if': 'CONFIG_POSIX' }
> +  'data': { 'username': 'str', 'keys': ['str'
> +    ]
> +  }

Again these extra line breaks are undesirable.


> +}
>  
>  ##
>  # @GuestDiskStats:
> @@ -1792,4 +1796,4 @@
>  ##
>  { 'command': 'guest-get-cpustats',
>    'returns': ['GuestCpuStats']
> -}
> +}
> \ No newline at end of file
> -- 
> 2.44.0
> 
> 

With regards,
Daniel

Thanks for the feedback, Daniel, I will get these issues resolved shortly. Thank you for your patience, this is my first time committing to QEMU. 
Aidan Leuck

-----Original Message-----
From: Daniel P. Berrangé <berrange@redhat.com> 
Sent: Friday, March 22, 2024 4:32 AM
To: Aidan Leuck <aidan_leuck@selinc.com>
Cc: qemu-devel@nongnu.org; kkostiuk@redhat.com
Subject: Re: [PATCH v2 1/2] Implement SSH commands in QEMU GA for Windows

[Caution - External]

On Thu, Mar 21, 2024 at 04:07:24PM +0000, aidan_leuck@selinc.com wrote:
> From: aidaleuc <aidan_leuck@selinc.com>
>
> Signed-off-by: aidaleuc <aidan_leuck@selinc.com>
> ---
>  qga/commands-windows-ssh.c | 848 
> +++++++++++++++++++++++++++++++++++++
>  qga/commands-windows-ssh.h |  26 ++
>  qga/meson.build            |   9 +-
>  qga/qapi-schema.json       |  22 +-
>  4 files changed, 892 insertions(+), 13 deletions(-)  create mode 
> 100644 qga/commands-windows-ssh.c  create mode 100644 
> qga/commands-windows-ssh.h
>
> diff --git a/qga/commands-windows-ssh.c b/qga/commands-windows-ssh.c 
> new file mode 100644 index 0000000000..566266f465
> --- /dev/null
> +++ b/qga/commands-windows-ssh.c
> @@ -0,0 +1,848 @@


> +static char *get_admin_ssh_folder(Error **errp) {
> +  // Allocate memory for the program data path

Please use C /* ... */  comments, not C++ comment style

> +  g_autofree char *programDataPath = NULL;  char *authkeys_path = 
> + NULL;  PWSTR pgDataW;

Nothing initializes pgDataW here.

> +  GError *gerr = NULL;

Declare that 'g_autoptr(GError) gerr = NULL', avoiding the need for manual g_Error_Free calls.

> +
> +  // Get the KnownFolderPath on the machine.
> +  HRESULT folderResult =
> +      SHGetKnownFolderPath(&FOLDERID_ProgramData, 0, NULL, &pgDataW);  
> + if (folderResult != S_OK) {

This method is the initializer for 'pgDataW', but in this error scenario, is there any guarantee that 'pgDataW'
will actually have been initialized ? We're about to jump to an 'error' label that will try to free this.

> +    error_setg(errp, "Failed to retrieve ProgramData folder");
> +    goto error;

QEMU indent standard is 4 spaces, rather than 2 spaces. Applies throughout this patch.

> +  }
> +
> +  // Convert from a wide string back to a standard character string.
> +  programDataPath = g_utf16_to_utf8(pgDataW, -1, NULL, NULL, &gerr);

If you put the 'CoTaskMemFree(pgDataW)' call here

> +  if (!programDataPath) {

and call error_setg(...., gerr->mssage); here

we can avoid the need for any 'error:' cleanup block at all. All places can just 'return NULL' immediately.

> +    goto error;
> +  }
> +
> +  // Build the path to the file.
> +  authkeys_path = g_build_filename(programDataPath, "ssh", NULL);  
> + CoTaskMemFree(pgDataW);  return authkeys_path;
> +
> +error:
> +  CoTaskMemFree(pgDataW);

...before we access pgDataW here potentially uninitialized.

> +
> +  if (gerr) {
> +    error_setg(errp,"Failed to convert program data path from wide string to standard utf 8 string. %s", gerr->message);
> +    g_error_free(gerr);
> +  }
> +
> +  return NULL;
> +}
> +
> +/*
> + * 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) {
> +  if (isAdmin) {
> +    return get_admin_ssh_folder(errp);
> +  }
> +
> +  // If not an Admin the SSH key is in the user directory.
> +  DWORD maxSize = MAX_PATH;

QEMU preference is for all variables to be declared at the start of the code scope block. This is especially important when using g_autofree at the same time as 'goto', as if a goto jumps over a variable declaration, it will remain uninitialized.

> +  g_autofree char* profilesDir = g_malloc(maxSize);

Use 'char *' rather than 'char*', and use g_new0 to guarantee the memory is initialized.

> +
> +  // 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 everyone group. This is used when the 
> +user is an Administrator
> + * This is consistent with the folder permissions that OpenSSH 
> +creates when it
> + * is installed. Anyone can read the file, but only Administrators 
> +and SYSTEM can
> + * modify the file.
> + *
> + * 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_admin(PWindowsUserInfo userInfo, PACL *pACL,
> +                             Error **errp) {
> +  PSID everyonePSID = NULL;
> +
> +  const int aclSize = 1;
> +  EXPLICIT_ACCESS eAccess[1];
> +
> +  // Zero out memory for the explicit access array  
> + ZeroMemory(&eAccess, aclSize * sizeof(EXPLICIT_ACCESS));

Calling ZeroMemory is redundant, just let the compiler do this

 EXPLICIT_ACCESS eAccess[1] = {};

> +
> +  // Create an entry for everyone (so they can at least read the folder).
> +  // This is consistent with other folders located in %PROGRAMDATA%  
> + bool converted = ConvertStringSidToSid(WORLD_SID, &everyonePSID);  
> + if (!converted) {
> +    error_setg_win32(errp, GetLastError(), "failed to retrieve Admin SID");
> +    goto error;
> +  }
> +
> +  // Set permissions for everyone group (they can only read the 
> + files)  eAccess[0].grfAccessPermissions = GENERIC_READ;  
> + eAccess[0].grfAccessMode = SET_ACCESS;  eAccess[0].grfInheritance = 
> + NO_INHERITANCE;  eAccess[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;  
> + eAccess[0].Trustee.TrusteeType = TRUSTEE_IS_GROUP;  
> + eAccess[0].Trustee.ptstrName = (LPTSTR)everyonePSID;
> +
> +  // 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 ACL entries for admin user %s %lu",
> +                     userInfo->username, setResult);
> +    goto error;
> +  }
> +
> +  LocalFree(everyonePSID);
> +
> +  // Free the old memory since we are going to overwrite the users  
> + // pointer  LocalFree(*pACL);  *pACL = pNewACL;
> +
> +  return true;
> +
> +error:
> +  LocalFree(everyonePSID);
> +  return false;
> +}
> +
> +/*
> + * 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;
> +
> +  // Zero out memory for the explicit access array  
> + ZeroMemory(&eAccess, aclSize * sizeof(EXPLICIT_ACCESS));
> +
> +  // 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];
> +
> +  // Zero out memory for the explicit access array  
> + ZeroMemory(&eAccess, aclSize * sizeof(EXPLICIT_ACCESS));
> +
> +  // 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;
> +  }
> +
> +  // If the user is an admin allow everyone to read the keys  if 
> + (!create_acl_admin(userInfo, pACL, errp)) {
> +    return false;
> +  }
> +
> +  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 approparite 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;
> +
> +  // 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;
> +  }
> +
> +  // Set the ACL on the file.
> +  if (SetNamedSecurityInfo(userInfo->authorizedKeyFile, SE_FILE_OBJECT,
> +                           DACL_SECURITY_INFORMATION, 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;
> +  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_malloc(sizeof(WindowsUserInfo));
> +
> +  // Set pointer so it can be cleaned up by the calle, 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);
> +  }
> +  if (gerr) {
> +    error_setg(errp, "Failed to convert username %s to wide string. %s",
> +               username, gerr->message);
> +    g_error_free(gerr);
> +  }
> +
> +  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 authekys 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) {
> +    // If we are not resetting the keys, read the 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); }
> diff --git a/qga/commands-windows-ssh.h b/qga/commands-windows-ssh.h 
> new file mode 100644 index 0000000000..7d68a1bcef
> --- /dev/null
> +++ b/qga/commands-windows-ssh.h
> @@ -0,0 +1,26 @@
> +/*
> + * Header file for commands-windows-ssh.c
> + *
> + * 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 <glib/gstrfuncs.h>
> +#include <stdbool.h>
> +typedef struct WindowsUserInfo {
> +  char *sshDirectory;
> +  char *authorizedKeyFile;
> +  char *username;
> +  char *SSID;
> +  bool isAdmin;
> +} WindowsUserInfo;
> +
> +typedef WindowsUserInfo *PWindowsUserInfo;
> +
> +void free_userInfo(PWindowsUserInfo info); 
> +G_DEFINE_AUTO_CLEANUP_FREE_FUNC(PWindowsUserInfo, free_userInfo, 
> +NULL);

> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json index 
> 9554b566a7..ffa7eb4082 100644
> --- a/qga/qapi-schema.json
> +++ b/qga/qapi-schema.json
> @@ -1599,8 +1599,10 @@
>  # Since: 5.2
>  ##
>  { 'command': 'guest-ssh-add-authorized-keys',
> -  'data': { 'username': 'str', 'keys': ['str'], '*reset': 'bool' },
> -  'if': 'CONFIG_POSIX' }
> +  'data': { 'username': 'str', 'keys': ['str'
> +    ], '*reset': 'bool'
> +  }

Don't insert these two extra linebreaks, it is already short enough as is.


> +}
>
>  ##
>  # @guest-ssh-remove-authorized-keys:
> @@ -1617,8 +1619,10 @@
>  # Since: 5.2
>  ##
>  { 'command': 'guest-ssh-remove-authorized-keys',
> -  'data': { 'username': 'str', 'keys': ['str'] },
> -  'if': 'CONFIG_POSIX' }
> +  'data': { 'username': 'str', 'keys': ['str'
> +    ]
> +  }

Again these extra line breaks are undesirable.


> +}
>
>  ##
>  # @GuestDiskStats:
> @@ -1792,4 +1796,4 @@
>  ##
>  { 'command': 'guest-get-cpustats',
>    'returns': ['GuestCpuStats']
> -}
> +}
> \ No newline at end of file
> --
> 2.44.0
>
>

With regards,
Daniel
--
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