qemu-ga: implement win32 guest-set-user-password

Use NetUserSetInfo() to set the user password.

This function is notoriously known to be problematic for users with EFS
encrypted files. But the alternative, NetUserChangePassword() requires
the old password. Nevertheless, The EFS file should be recovered by
changing back to the old password.

Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com>
---
 configure            |  2 +-
 qga/commands-win32.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 76 insertions(+), 3 deletions(-)

ping

On Tue, Jun 30, 2015 at 4:37 PM, Marc-André Lureau
<marcandre.lureau@gmail.com> wrote:
> Use NetUserSetInfo() to set the user password.
>
> This function is notoriously known to be problematic for users with EFS
> encrypted files. But the alternative, NetUserChangePassword() requires
> the old password. Nevertheless, The EFS file should be recovered by
> changing back to the old password.
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com>
> ---
>  configure            |  2 +-
>  qga/commands-win32.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 76 insertions(+), 3 deletions(-)
>
> diff --git a/configure b/configure
> index 3063739..400de0d 100755
> --- a/configure
> +++ b/configure
> @@ -732,7 +732,7 @@ if test "$mingw32" = "yes" ; then
>    sysconfdir="\${prefix}"
>    local_statedir=
>    confsuffix=""
> -  libs_qga="-lws2_32 -lwinmm -lpowrprof $libs_qga"
> +  libs_qga="-lws2_32 -lwinmm -lpowrprof -lnetapi32 $libs_qga"
>  fi
>
>  werror=""
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index fbddc8b..d31530c 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -16,6 +16,8 @@
>  #include <powrprof.h>
>  #include <stdio.h>
>  #include <string.h>
> +#include <lm.h>
> +
>  #include "qga/guest-agent-core.h"
>  #include "qga/vss-win32.h"
>  #include "qga-qmp-commands.h"
> @@ -676,12 +678,84 @@ int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
>      return -1;
>  }
>
> +static gchar *
> +get_net_error_message(gint error)
> +{
> +    HMODULE module = NULL;
> +    gchar *retval = NULL;
> +    wchar_t *msg = NULL;
> +    int flags, nchars;
> +
> +    flags = FORMAT_MESSAGE_ALLOCATE_BUFFER
> +        |FORMAT_MESSAGE_IGNORE_INSERTS
> +        |FORMAT_MESSAGE_FROM_SYSTEM;
> +
> +    if (error >= NERR_BASE && error <= MAX_NERR) {
> +        module = LoadLibraryExW(L"netmsg.dll", NULL, LOAD_LIBRARY_AS_DATAFILE);
> +
> +        if (module != NULL) {
> +            flags |= FORMAT_MESSAGE_FROM_HMODULE;
> +        }
> +    }
> +
> +    FormatMessageW(flags, module, error, 0, (LPWSTR)&msg, 0, NULL);
> +
> +    if (msg != NULL) {
> +        nchars = wcslen(msg);
> +
> +        if (nchars > 2 && msg[nchars-1] == '\n' && msg[nchars-2] == '\r') {
> +            msg[nchars-2] = '\0';
> +        }
> +
> +        retval = g_utf16_to_utf8(msg, -1, NULL, NULL, NULL);
> +
> +        LocalFree(msg);
> +    }
> +
> +    if (module != NULL) {
> +        FreeLibrary(module);
> +    }
> +
> +    return retval;
> +}
> +
>  void qmp_guest_set_user_password(const char *username,
>                                   const char *password,
>                                   bool crypted,
>                                   Error **errp)
>  {
> -    error_setg(errp, QERR_UNSUPPORTED);
> +    NET_API_STATUS nas;
> +    char *rawpasswddata = NULL;
> +    size_t rawpasswdlen;
> +    wchar_t *user, *wpass;
> +    USER_INFO_1003 pi1003 = { 0, };
> +
> +    if (crypted) {
> +        error_setg(errp, QERR_UNSUPPORTED);
> +        return;
> +    }
> +
> +    rawpasswddata = (char *)g_base64_decode(password, &rawpasswdlen);
> +    rawpasswddata = g_renew(char, rawpasswddata, rawpasswdlen + 1);
> +    rawpasswddata[rawpasswdlen] = '\0';
> +
> +    user = g_utf8_to_utf16(username, -1, NULL, NULL, NULL);
> +    wpass = g_utf8_to_utf16(rawpasswddata, -1, NULL, NULL, NULL);
> +
> +    pi1003.usri1003_password = wpass;
> +    nas = NetUserSetInfo(NULL, user,
> +                         1003, (LPBYTE)&pi1003,
> +                         NULL);
> +
> +    if (nas != NERR_Success) {
> +        gchar *msg = get_net_error_message(nas);
> +        error_setg(errp, "failed to set password: %s", msg);
> +        g_free(msg);
> +    }
> +
> +    g_free(user);
> +    g_free(wpass);
> +    g_free(rawpasswddata);
>  }
>
>  GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
> @@ -709,7 +783,6 @@ GList *ga_command_blacklist_init(GList *blacklist)
>      const char *list_unsupported[] = {
>          "guest-suspend-hybrid", "guest-network-get-interfaces",
>          "guest-get-vcpus", "guest-set-vcpus",
> -        "guest-set-user-password",
>          "guest-get-memory-blocks", "guest-set-memory-blocks",
>          "guest-get-memory-block-size",
>          "guest-fsfreeze-freeze-list", "guest-get-fsinfo",
> --
> 2.4.3
>

On Tue, Jun 30, 2015 at 04:37:13PM +0200, Marc-André Lureau wrote:
> Use NetUserSetInfo() to set the user password.
> 
> This function is notoriously known to be problematic for users with EFS
> encrypted files. But the alternative, NetUserChangePassword() requires
> the old password. Nevertheless, The EFS file should be recovered by
> changing back to the old password.
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com>
> ---
>  configure            |  2 +-
>  qga/commands-win32.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 76 insertions(+), 3 deletions(-)

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>


For reference, I compared with MS recommendations here

  https://support.microsoft.com/en-us/kb/151546

and this looks correct for way to administratively change passwords
without knowing the original password.

Regards,
Daniel

Quoting Marc-André Lureau (2015-06-30 09:37:13)
> Use NetUserSetInfo() to set the user password.
> 
> This function is notoriously known to be problematic for users with EFS
> encrypted files. But the alternative, NetUserChangePassword() requires
> the old password. Nevertheless, The EFS file should be recovered by
> changing back to the old password.
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com>

Thanks, applied to qga tree:
  https://github.com/mdroth/qemu/commits/qga

> ---
>  configure            |  2 +-
>  qga/commands-win32.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++--
>  2 files changed, 76 insertions(+), 3 deletions(-)
> 
> diff --git a/configure b/configure
> index 3063739..400de0d 100755
> --- a/configure
> +++ b/configure
> @@ -732,7 +732,7 @@ if test "$mingw32" = "yes" ; then
>    sysconfdir="\${prefix}"
>    local_statedir=
>    confsuffix=""
> -  libs_qga="-lws2_32 -lwinmm -lpowrprof $libs_qga"
> +  libs_qga="-lws2_32 -lwinmm -lpowrprof -lnetapi32 $libs_qga"
>  fi
> 
>  werror=""
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index fbddc8b..d31530c 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -16,6 +16,8 @@
>  #include <powrprof.h>
>  #include <stdio.h>
>  #include <string.h>
> +#include <lm.h>
> +
>  #include "qga/guest-agent-core.h"
>  #include "qga/vss-win32.h"
>  #include "qga-qmp-commands.h"
> @@ -676,12 +678,84 @@ int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
>      return -1;
>  }
> 
> +static gchar *
> +get_net_error_message(gint error)
> +{
> +    HMODULE module = NULL;
> +    gchar *retval = NULL;
> +    wchar_t *msg = NULL;
> +    int flags, nchars;
> +
> +    flags = FORMAT_MESSAGE_ALLOCATE_BUFFER
> +        |FORMAT_MESSAGE_IGNORE_INSERTS
> +        |FORMAT_MESSAGE_FROM_SYSTEM;
> +
> +    if (error >= NERR_BASE && error <= MAX_NERR) {
> +        module = LoadLibraryExW(L"netmsg.dll", NULL, LOAD_LIBRARY_AS_DATAFILE);
> +
> +        if (module != NULL) {
> +            flags |= FORMAT_MESSAGE_FROM_HMODULE;
> +        }
> +    }
> +
> +    FormatMessageW(flags, module, error, 0, (LPWSTR)&msg, 0, NULL);
> +
> +    if (msg != NULL) {
> +        nchars = wcslen(msg);
> +
> +        if (nchars > 2 && msg[nchars-1] == '\n' && msg[nchars-2] == '\r') {
> +            msg[nchars-2] = '\0';
> +        }
> +
> +        retval = g_utf16_to_utf8(msg, -1, NULL, NULL, NULL);
> +
> +        LocalFree(msg);
> +    }
> +
> +    if (module != NULL) {
> +        FreeLibrary(module);
> +    }
> +
> +    return retval;
> +}
> +
>  void qmp_guest_set_user_password(const char *username,
>                                   const char *password,
>                                   bool crypted,
>                                   Error **errp)
>  {
> -    error_setg(errp, QERR_UNSUPPORTED);
> +    NET_API_STATUS nas;
> +    char *rawpasswddata = NULL;
> +    size_t rawpasswdlen;
> +    wchar_t *user, *wpass;
> +    USER_INFO_1003 pi1003 = { 0, };
> +
> +    if (crypted) {
> +        error_setg(errp, QERR_UNSUPPORTED);
> +        return;
> +    }
> +
> +    rawpasswddata = (char *)g_base64_decode(password, &rawpasswdlen);
> +    rawpasswddata = g_renew(char, rawpasswddata, rawpasswdlen + 1);
> +    rawpasswddata[rawpasswdlen] = '\0';
> +
> +    user = g_utf8_to_utf16(username, -1, NULL, NULL, NULL);
> +    wpass = g_utf8_to_utf16(rawpasswddata, -1, NULL, NULL, NULL);
> +
> +    pi1003.usri1003_password = wpass;
> +    nas = NetUserSetInfo(NULL, user,
> +                         1003, (LPBYTE)&pi1003,
> +                         NULL);
> +
> +    if (nas != NERR_Success) {
> +        gchar *msg = get_net_error_message(nas);
> +        error_setg(errp, "failed to set password: %s", msg);
> +        g_free(msg);
> +    }
> +
> +    g_free(user);
> +    g_free(wpass);
> +    g_free(rawpasswddata);
>  }
> 
>  GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
> @@ -709,7 +783,6 @@ GList *ga_command_blacklist_init(GList *blacklist)
>      const char *list_unsupported[] = {
>          "guest-suspend-hybrid", "guest-network-get-interfaces",
>          "guest-get-vcpus", "guest-set-vcpus",
> -        "guest-set-user-password",
>          "guest-get-memory-blocks", "guest-set-memory-blocks",
>          "guest-get-memory-block-size",
>          "guest-fsfreeze-freeze-list", "guest-get-fsinfo",
> -- 
> 2.4.3
>