So I'm doing some testing with data encryption per a course I'm taking in school (for this assignment we're meant to use only a Windows environment), and I'm able to use Windows built-in "cipher.exe" tool just fine for what we need to do.
I made a small .txt file (my plain text), and I encrypted it using "cipher /e PlainText.txt" which has no error. However, I want to be able to view the ciphertext as well. How would one go about doing this? I tried logging in as a user that didn't have the proper access to the file and instead of seeing ciphertext it just comes up blank saying "Access Denied".
Thank you for any ideas.
The way you open an encrypted file in order to read its raw encrypted contents (e.g. for a backup/restore application) is to use the:
OpenEncryptedFileRaw,
ReadEncryptedFileRaw,
WriteEncryptedFileRaw, and
CloseEncryptedFileRaw
api functions.
Writing the code on the fly, in a hypothetical hybrid language:
void ExportEncryptedFileToStream(String filename, Stream targetStream)
{
Pointer context;
res = OpenEncryptedFileRaw("C:\Users\Ian\wallet.dat", 0, ref context);
if (res <> ERROR_SUCCESS)
RaiseWin32Error(res);
try
{
res = ReadEncryptedFileRaw(exportCallback, null, context);
if (res != ERROR_SUCCESS)
RaiseWin32Error(res);
}
finally
{
CloseEncryptedFileRaw(context)
}
}
function ExportCallback(pbData: PBYTE, pvCallbackContext: PVOID, ulLength: ULONG): DWORD
{
Stream targetStream = Stream(pvCallbackContext);
try
{
targetStream.Write(pbData, ulLength);
}
catch (Exception e)
{
return ERROR_WRITE_FAULT;
}
return ERROR_SUCCESS;
}
Note: Any code released into public domain. No attribution required.
Related
Currently I am developing an C# console application using .NET 4.5 to set some configuration values of the access point. This access point is in my local network. Further I am using SnmpSharpNet library to make SNMP requests. To make the SNMP requests I used SNMP version 2.
The problem is that I can't do SET request to the access point and it always responds with "no-access" (error code 6). But I can do GET request without a problem. I checked the MIB file as well and the variable which I am going to change also has read-write access.
This is the code I wrote.
private static LogFile log;
private static SnmpV2Packet response;
private static UdpTarget target;
static void Main(string[] args)
{
try
{
log = new LogFile(args[0]);
target = new UdpTarget((IPAddress)new IpAddress("<host address>"));
Pdu pdu = new Pdu();
pdu.Type = PduType.Set;
pdu.VbList.Add(new Oid("1.3.6.1.4.1.2356.11.2.88.2.0"), new Integer32(1111));
AgentParameters aparam = new AgentParameters(SnmpVersion.Ver2, new OctetString("public"));
response = (SnmpV2Packet)target.Request(pdu, aparam);
}
catch (Exception ex)
{
log.LogError("Request failed with the exception " + ex, "Main");
target.Close();
return;
}
if (response == null)
{
log.LogError("Error in SNMP request", "Main");
}
else
{
//If an incorrect response
if (response.Pdu.ErrorStatus != 0)
{
log.LogError("SNMP agent returned error status " + response.Pdu.ErrorStatus, "Main");
}
//If a successful response
else
{
log.LogInfo("Value of the " + response.Pdu[0].Oid.ToString() + "changed to " + response.Pdu[0].Value.ToString(), "Main");
}
}
target.Close();
log.CloseLogFile();
}
This is the part related to the variable in the MIB file
-- {SCALAR} 1.3.6.1.4.1.2356.11.2.88.2
lcsSetupWirelessEpaperPort OBJECT-TYPE
SYNTAX Integer32 (0..65535)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"-- empty --"
::= { lcsSetupWirelessEpaper 2 }
I tired same using Net-SNMP on the command line also. but the result was same.
Can someone please tell me what would be the issue and what I is the point I am missing here.
Thank you.
A "no-access" (SNMP error code 6) could also indicate that SNMP community you are using ( I'm guessing it's "public" ) does not have write access. A monitoring system, for instance, should be able to read (GET) certain values, but not write (SET) them. From a security point-of-view, it is desirable to use a SNMP community that only has read access in this case.
Check the SNMP community configuration of your AP, to make sure it has write access. I would suggest adding a new community with write access, rather than changing access for "public".
I am trying to make a XBAP application communicating with a webservice with login.
But I want the user to skip the login step if they already logged in the last seven days.
I got it to work using html/aspx.
But it fails continuously with XBAP.
While debugging, the application is given full trust.
This is the code I have so far to write the cookie:
protected static void WriteToCookie(
string pName,
Dictionary<string, string> pData,
int pExiresInDays)
{
// Set the cookie value.
string data = "";
foreach (string key in pData.Keys)
{
data += String.Format("{0}={1};", key, pData[key]);
}
string expires = "expires=" + DateTime.Now.AddDays(pExiresInDays).ToUniversalTime().ToString("r");
data += expires;
try
{
Application.SetCookie(new Uri(pName), data);
}
catch (Exception ex)
{
}
}
And this is what I have to read the cookie:
protected static Dictionary<string, string> ReadFromCookie(
string pName)
{
Dictionary<string, string> data = new Dictionary<string, string>();
try
{
string myCookie = Application.GetCookie(new Uri(pName));
// Returns the cookie information.
if (String.IsNullOrEmpty(myCookie) == false)
{
string[] splitted = myCookie.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
string[] sub;
foreach(string split in splitted)
{
sub = split.Split(new char[] { ':' }, StringSplitOptions.RemoveEmptyEntries);
if (sub[0] == "expires")
{
continue;
}
data.Add(sub[0], sub[1]);
}
}
}
catch(Exception ex)
{
}
return data;
}
The pName is set with:
string uri = "http://MyWebSiteName.com";
When the user authenticate the first time, I call the WriteToCookie function and set it with 7 days to expire.
It looks like everything is fine as I get no exception of error messages. (I have a break point in the catch)
After that, I close the session and start it again.
The first thing I do is a ReadFromCookie.
Then I get an exception with the following message: No more data is available
So my application is sending the user automatically back to the login screen.
I also tried to do a ReadFromCookie right after the WriteToCookie in the same session, and I get the same error.
Application.SetCookie(new Uri("http://MyWebSiteName.com/WpfBrowserApplication1.xbap"), "Hellllo");
string myCookie2 = Application.GetCookie(new Uri("http://MyWebSiteName.com/WpfBrowserApplication1.xbap"));
It seems to me that the cookie is not even written in the first place.
So I am guessing I am doing something wrong.
Maybe the uri I am using is wrong. Is there a specific format needed for it?
Just like you need a very specific format for the expire date.
I have been searching quite a lot of internet for a good sample/tutorial about using cookies with XBAP, and I could not find anything really well documented or tested.
A lot of people say that it works, but no real sample to try.
A lot of people also handle the authentication in html, then go to the XBAP after successfully reading/writing the cookies.
I would prefer a full XBAP solution if possible.
To answer some questions before they are asked, here are the project settings:
Debug:
Command line arguments: -debug -debugSecurityZoneURL http://MyWebSiteName.com "C:\Work\MyWebSiteName\MyWebSiteNameXBAP\bin\Debug\MyWebSiteNameXBAP.xbap"
Security:
Enable ClickOnce security settings (Checked)
This is a full trust application (selected)
I also created a certificate, and added it the 3 stores like explained in "publisher cannot be verified" message displayed
So I do not have the warning popup anymore. I just wanted to make sure that it was not a permission issue.
Finally found the answer to this problem.
Thanks for this CodeProject I was finally able to write/read cookies from the XBAP code.
As I had guessed, the URI needs to be very specific and you cannot pass everything you want in it.
What did the trick was using: BrowserInteropHelper.Source
In the end the read/write code looks like:
Application.SetCookie(BrowserInteropHelper.Source, data);
string myCookie = Application.GetCookie(BrowserInteropHelper.Source);
It looks like you cannot use ';' to separate your own data.
If you do so, you will only get the first entry in your data.
Use a different separator (ex: ':') and then you can get everything back
The data look like this:
n=something:k=somethingElse;expires=Tue, 12 May 2015 14:18:56 GMT ;
The only thing I do not get back from Application.GetCookie is the expire date.
Not sure if it is normal or not. Maybe it is flushed out automatically for some reason. If someone knows why, I would appreciate a comment to enlighten me.
At least now I can read/write data to the cookie in XBAP. Yeah!
I have a HP Scanjet 7000 (duplex & ADF scanner) and a HP Scanjet 5500c (only ADF) and a scanner program I'm developing which uses WIA 2.0 on Windows 7.
The problem is that the code works perfectly on the older scanner model, but on the newer one the code seems to run just fine through the first page, then fail on the second. If I step through the code around the following line;
image = (WIA.ImageFile)wiaCommonDialog.ShowTransfer(item, wiaFormatTIFF, false);
the old scanner stops and waits for another call to be made on the same reference, but the newer one just runs through all it's pages from the feeder in one continuous operation.
I notice if I'm using the default scanning program in Windows 7, the newer one returns a single .tif file which contains all the separate pages. The older one returns separate .jpg files (one for each page).
This indicates to me that the newer scanner is scanning through its whole feeder before it is ready to return a collection of images where the older one returns ONE image between each page scanned.
How can I support this behavior in code? The following is part of the relevant code which works on the older scanner model:
public static List<Image> Scan(string scannerId)
{
List<Image> images = new List<Image>();
List<String> tmp_imageList = new List<String>();
bool hasMorePages = true;
bool useAdf = true;
bool duplex = false;
int pages = 0;
string fileName = null;
string fileName_duplex = null;
WIA.DeviceManager manager = null;
WIA.Device device = null;
WIA.DeviceInfo device_infoHolder = null;
WIA.Item item = null;
WIA.ICommonDialog wiaCommonDialog = null;
manager = new WIA.DeviceManager();
// select the correct scanner using the provided scannerId parameter
foreach (WIA.DeviceInfo info in manager.DeviceInfos)
{
if (info.DeviceID == scannerId)
{
// Find scanner to connect to
device_infoHolder = info;
break;
}
}
while (hasMorePages)
{
wiaCommonDialog = new WIA.CommonDialog();
// Connect to scanner
device = device_infoHolder.Connect();
if (device.Items[1] != null)
{
item = device.Items[1] as WIA.Item;
try
{
if ((useAdf) || (duplex))
SetupADF(device, duplex); //Sets the right properties in WIA
WIA.ImageFile image = null;
WIA.ImageFile image_duplex = null;
// scan image
image = (WIA.ImageFile)wiaCommonDialog.ShowTransfer(item, wiaFormatTIFF, false);
if (duplex)
{
image_duplex = (ImageFile)wiaCommonDialog.ShowTransfer(item, wiaFormatPNG, false);
}
// save (front) image to temp file
fileName = Path.GetTempFileName();
tmp_imageList.Add(fileName);
File.Delete(fileName);
image.SaveFile(fileName);
image = null;
// add file to images list
images.Add(Image.FromFile(fileName));
if (duplex)
{
fileName_duplex = Path.GetTempFileName();
tmp_imageList.Add(fileName_duplex);
File.Delete(fileName_duplex);
image_duplex.SaveFile(fileName_duplex);
image_duplex = null;
// add file_duplex to images list
images.Add(Image.FromFile(fileName_duplex));
}
if (useAdf || duplex)
{
hasMorePages = HasMorePages(device); //Returns true if the feeder has more pages
pages++;
}
}
catch (Exception exc)
{
throw exc;
}
finally
{
wiaCommonDialog = null;
manager = null;
item = null;
device = null;
}
}
}
device = null;
return images;
}
Any help on this issue would be very much appreciated! I can't seem to find a working solution on the web. Just unanswered forum posts from people with the same problem.
we had a very similar problem and various solutions, e.g. by setting certain properties, did not help. The main problem was that the scanner (ADF) retracted all pages on startup, regardless of what was happening in the program code.
The process repeatedly led to errors, since "too much" was made before the next page was scanned. This applies in particular to the fact that another "Connect" was attempted.
For this reason, we have modified the code so that the individual pages can be read in as quickly as possible:
public List<Image> Scan(string deviceID)
{
List<Image> images = new List<Image>();
WIA.ICommonDialog wiaCommonDialog = new WIA.CommonDialog();
WIA.Device device = this.Connect(deviceID);
if (device == null)
return images;
WIA.Item item = device.Items[1] as WIA.Item;
List<WIA.ImageFile> wiaImages = new List<ImageFile>();
try
{
// scan images
do
{
WIA.ImageFile image = (WIA.ImageFile)wiaCommonDialog.ShowTransfer(item, wiaFormatJPEG, false);
wiaImages.Add(image);
} while (true);
}
catch (System.Runtime.InteropServices.COMException ex)
{
if ((uint)ex.ErrorCode != WIA_PROPERTIES.WIA_ERROR_PAPER_EMPTY)
throw ex;
}
catch (Exception ex)
{
throw ex;
}
foreach (WIA.ImageFile image in wiaImages)
this.DoImage(images, image);
return images;
}
I see you're calling a method called SetupADF, which is not shown, that presumably sets some properties on the device object. Have you tried setting WIA_DPS_PAGES (property 3096) and/or WIA_DPS_SCAN_AHEAD_PAGES (property 3094)?
I have a blog post about scanning from an ADF in Silverlight, and I believe a commenter came up against the same issue you're having. Setting WIA_DPS_PAGES to 1 fixed it for him. I ended up modifying my code's SetDeviceProperties method to set WIA_DPS_PAGES to 1 and WIA_DPS_SCAN_AHEAD_PAGES to 0.
After alot of trial and error I stumbled upon a solution which worked for reasons I'm not quite sure of. It seems like the ShowTransfer() method was unable to convert the page to .png or .tiff WHILE scanning. Setting the format to JPEG or BMP actually solved the issue for me:
image = (ImageFile)scanDialog.ShowTransfer(item, wiaFormatJPEG, false);
I think I saw somewhere on the web that this method actually returns BMP regardless of the format specified. Might be that converting the image to png or tiff is too heavy as opposed to using bmp or jpeg.
On a sidenote, I'm setting the property setting: 3088 to 0x005 (adf AND duplex mode).
I would like to ask if there is a standard to store username and password in a Windows Phone application.
I am working on a project that validates the user on every request that is called. So, I want to store the username and password. Maybe even give them the possibility to "remember me", so if there isn't a standard for doing that, I will have to write it myself, but I'm guessing that Microsoft has a build-in one.
Use ProtectedData.
I found this example on Kevin D. Wolf's efficientcoder.net :
public static String Password {
get {
if (IsolatedStorageSettings.ApplicationSettings.Contains(STR_PASSWORÐ)) {
var bytes = IsolatedstorageSettings.Applicationsettings[STR_PASSwORÐ] as byte[];
var unEncrypteBytes = ProtectedData.Unprotect(bytes, null);
return Encoding.UTF8.GetString(unEncrypteBytes, 0, unEncrypteBytes.Length);
} else {
return string.Empty;
}
}
set {
var encryptedBytes = ProtectedData.Protect(Encoding.UTF8.GetBytes(value), null);
IsolatedStorageSettings.ApplicationSettings[STR_PASSWORÐ] = encryptedBytes;
}
}
(Apologies for the cut and paste I had to use a text from image scan)
You should encrypt you passwords and other sensitive data using the ProtectedData class routines, and manually store them in Isolated Storage for your application.
To encrypt
To decrypt
Also, make sure you add a reference to mscorelib extended to your project. I had to learn this the hard way.
A good article on the topic is:
http://debugmode.net/2011/10/16/protecting-password-or-any-data-in-windows-phone-7-using-data-protection-api/
My script fetches xml via httpConnection and saves to persistent store. No problems there.
Then I loop through the saved data to compose a list of image url's to fetch via queue.
Each of these requests calls the httpConnection thread as so
...
public synchronized void run()
{
HttpConnection connection = (HttpConnection)Connector.open("http://www.somedomain.com/image1.jpg");
connection.setRequestMethod("GET");
String contentType = connection.getHeaderField("Content-type");
InputStream responseData = connection.openInputStream();
connection.close();
outputFinal(responseData, contentType);
}
public synchronized void outputFinal(InputStream result, String contentType) throws SAXException, ParserConfigurationException, IOException
{
if(contentType.startsWith("text/"))
{
// bunch of xml save code that works fine
}
else if(contentType.equals("image/png") || contentType.equals("image/jpeg") || contentType.equals("image/gif"))
{
// how to save images here?
}
else
{
//default
}
}
What I can't find any good documentation on is how one would take the response data and save it to an image stored on the device.
Maybe I just overlooked something very obvious. Any help is very appreciated.
Thanks
I tried following this advise and found the same thing I always find when looking up BB specific issues: nothing.
The problem is that every example or post assumes you know everything about the platform.
Here's a simple question: What line of code writes the read output stream to the blackberry device? What path? How do I retrieve it later?
I have this code, which I do not know if it does anything because I don't know where it is supposedly writing to or if that's even what it is doing at all:
** filename is determined on a loop based on the url called.
FileOutputStream fos = null;
try
{
fos = new FileOutputStream( File.FILESYSTEM_PATRIOT, filename );
byte [] buffer = new byte [262144];
int byteRead;
while ((byteRead = result.read (buffer ))!=- 1)
{
fos.write (buffer, 0, byteRead);
}
fos.flush();
fos.close();
}
catch(IOException ieo)
{
}
finally
{
if(fos != null)
{
fos.close();
}
}
The idea is that I have some 600 images pulled from a server. I need to loop the xml and save each image to the device so that when an entity is called, I can pull the associated image - entity_id.png - from the internal storage.
The documentation from RIM does not specify this, nor does it make it easy to begin figuring it out.
This issue does not seem to be addressed on this forum, or others I have searched.
Thanks
You'll need to use the Java FileOutputStream to do the writing. You'll also want to close the connection after reading the data from the InputStream (move outputFinal above your call to close). You can find all kinds of examples regarding FileOutputStream easily.
See here for more. Note that in order to use the FileOutputStream your application must be signed.