A runtime, architecture, and libraries for Microsoft Windows used for creating applications.

learn more… | top users | synonyms (1)

0
votes
1answer
320 views

How to encrypt files without giving the user access? [duplicate]

I don't know if I should ask this question on security.SE or stackoverflow, so please move my post if necessary. I want to store my (C#) application data in a way that the user cannot read or modify ...
9
votes
2answers
2k views

Data Encryption and Key Management in C#

Which route to take, what are the pros and cons, which is more secure.. Generate AES key, encrypt the data with it and then encrypt the AES key with RSA, save the encrypted data and encrypted AES ...
2
votes
2answers
145 views

Why would encrypting data result in a call to a Domain Controller

This KB article mentions an issue where signing or encrypting information may result in a network IO call to a Domain Controller. Apparently the RSACryptoServiceProvider's SignData and VerifyData ...
2
votes
1answer
217 views

How to Verify the Identity of the Caller of a Web Service

I have a server which is composed of a page and a web service. The web service is intended to be used by a Windows Phone mobile application that I will develop myself. Now, my question is, how do I ...
7
votes
1answer
703 views

A practical .NET Remoting Architecture exploit

If you were to demonstrate a .NET Remoting Architecture vulnerability with a practical attack, which one would you choose? I've read J. Forshaw's white paper on Breaking .NET Through Serialization ...
-6
votes
1answer
4k views

Asymmetric encryption algorithms [closed]

What are the best asymmetric encryption algorithms out there? I am trying to use RSA in my project howoever I have read that it is not quite secure as other asymmetric encryption algorithms.
2
votes
1answer
110 views

How does a function certificate work?

Say that we have a client / server solution (written in .NET). If we want to use a certificate for the TCP communication, is it enough to use one function/service certificate to encrypt communication ...
1
vote
0answers
312 views

OTR and/or SecureIM library for C# .NET [closed]

I'm looking for implementations (or even wrappers) for OTR or SecureIM encrypted chat protocols usable from C#. Currently I found none, and considering porting Java OTR library and/or wrapping ...
1
vote
2answers
1k views

Questions to hybrid encryption. RSA with AES

I want to use a hybrid encryption in my application, so after reading a lot of lines I ended with this implemantation, please critizie it ;) (I want to stick to .Net) byte[] aesKey = ...
8
votes
4answers
2k views

What Partial Homomorphic Encryption implementations exist and how do I leverage them?

It appears that only Partial Homomorphic Encryption(P.H.E.) is practical for modern day (2011) use. However I'm having difficulty locating libraries (FOSS or otherwise) that enable me to leverage ...
5
votes
3answers
516 views

Why must all classes' data members be set to private?

In OO programming courses, teachers always tells us to set class members to private unless there is a good reason because it is more "secured". How does setting members to private makes the program ...
1
vote
2answers
90 views

How do I sanitize and check large numbers that will be sent to an unmanaged BigNum library like GMP?

I need to process data that is sent by users in a LargeNumber format. My current choices are BigInteger (.Net Managed Code) IntX (Managed Code, faster for some operations) GMP / MPIR (Unmanaged ...
1
vote
2answers
220 views

How to check whether the cookie is set securely

I found solution for setting asp.net_sessionid cookie as secure. The solution is to make changes in web.config file as given below. <\system.web> I want to know if this change is setting the ...
6
votes
2answers
958 views

Production ready bcrypt implementation for .NET

Which, if any, .NET / C# bcrypt implementations are considered suitable for production environments? I have seen CryptSharp and BCrypt.Net mentioned in answers to other questions but without any ...
4
votes
2answers
531 views

How to correctly implement AES in a backup application

I am writing a back-up application which should have the feature of encrypting the back-up. It must encrypt file data, paths and filenames. The application is being written in C# (.NET). Target is ...
1
vote
2answers
751 views

UNION SQL Injection

I'm trying to demo SQL Injection with a UNION query but I'm not getting results. This is the C# code and the database is SQL Server 2008 R2: string cString = "server=.\\sqlexpress; ...
1
vote
1answer
452 views

Setting up ASP.NET web application on internet for first time; Are these security measures enough?

I have a web application running on IIS 7 in offices on LAN and I wish to upload it to hosting space on (Godaddy) because I like it to be used in my other offices (other cities). This application ...
5
votes
4answers
1k views

Gold Standard for password hashing

I've developing a web application that will be dealing with highly sensitive information and I want to ensure the hashing of passwords is gold standard. Ideally I'd go for per-user salted SHA512 ...
6
votes
1answer
753 views

Secure query string parameters

I have an application which use the Thick box jQuery component to open a popup page . And I pass my parameters in query string like this : <a id="btnShowPopup6" runat="server" class="thickbox" ...
2
votes
1answer
580 views

Are there any functional differences in the implementations of OpenSSL, GnuTLS, Java's TLS, and .NET's TLS?

Question Are there any functional (or detectable) differences between the various implementations of SSL/TLS? What are the differences between them? (e.g. which ones implement "False Start") ...
2
votes
2answers
261 views

Are GUID visible when compiling a .NET project?

I know if a person has a GUID from a machine that person can figure out if other guid belongs to that machine. In a .NET project (csproj and the visual studions solution file) GUIDs are generated. If ...
9
votes
3answers
1k views

How can I encrypt a file with .NET and have the same file size of the original file?

I'm using .NET and I've written an awesome routine (xD) that encrypts and decrypts a file using AES256 CBC. It works perfectly, but now they told me that the encrypted file must be of the same size of ...
5
votes
1answer
979 views

“Hello World” example of a Buffer Overflow attack in many programming languages

I'm looking for a very simple application that has an intentional Buffer Overflow embedded in it. I'm assuming this possible in systems where DEP and ASLR are not being used Ideally (and if ...
2
votes
3answers
814 views

How to do a virus scan before post attachments in asp.net application

How to do a virus scan before post attachments in asp.net application,when they find a virus on to give up post attachments,otherwise proceed to upload. I wonder if there are any APIs out there where ...
1
vote
4answers
3k views

What Are The Best Practices (Application Security Policy) For Modifying Rijndael Salt, IV, Pass Phrase

(Note: originally posted in SO - advised to post on SSE) With regards to Rijndael encryption, what (if any) are the best practices (and consequences) regarding the periodic modification of one or ...
4
votes
1answer
3k views

Is PBKDF2 only SHA1 in C#?

I can't find a way of specifying the hashing algorithm used by the PBKDF2 (the Rfc2898DeriveBytes class) implementation in C# System.Security.Cryptography. It seems to be just SHA1. Am I missing ...
8
votes
2answers
2k views

How should an application store its credentials

When developing desktop applications, you will occasionally have to store credentials somewhere to be able to authenticate your application. An example of this is a Facebook app ID + secret, another ...
4
votes
1answer
1k views

Encrypt Medicare card numer in C# in ASP.NET

I am giving a free consultation for a non profit organisation that wants a simple system to manage multiple groups with a schedule component, etc. and also manage the medical informations of the kids. ...
2
votes
1answer
104 views

Using MySQL in .NET and other easily-decompiled languages?

How would people use MySQL in C#, or really any other managed application? Couldn't someone simply decompile the application and find out the password/etc. for the database?
2
votes
0answers
63 views

Using GPG or PGP for symmetric database encryption/decryption in c# [duplicate]

Possible Duplicate: Using GPG or PGP for symmetric database encryption/decryption in c# I am looking to symmetrically encrypt/decrypt information in a database. This info consists of short ...
3
votes
3answers
1k views

Securing AES 128 encrypted ZIPs against brute force attacks

How long would it take to brute force decrypt an AES 128 encrypted zip file if the password is 8 characters long in the range of A-Z, a-z, 1-9? Does it make any difference if .NET's System.Random ...
4
votes
1answer
296 views

A simple example for showing the use of Data Execution Prevention (DEP) security feature

I am finding it really hard to figure out why we need a DEP! Microsoft states this about DEP: The primary benefit of DEP is to help prevent code execution from data pages. Typically, code ...
4
votes
2answers
254 views

How do I remove or anonymize file names and path that are stored in compiled .NET exe output?

When an exception occurs in a .NET application, the exception output also includes the path and file name of the code file that resided on the developer's machine. This shares some information that ...
1
vote
1answer
159 views

What does a IT Security Pro need to know about .NET Code Access Security (CAS)?

Background In .NET 1.0 through 3.5 administrators could administer the runtime security policy through mscorcfg. Aparrently many of these security features have been removed in .NET 4.0,. ...
5
votes
1answer
122 views

Does every security patch get back ported to every .NET framework? Are there exceptions to the rule?

I can imagine a scenario where Microsoft will create a security patch for some versions of .NET and not others. This might occur in occasions it's too expensive to regression test and back port all ...
4
votes
1answer
2k views

What's the risk of changing permissions of the Security Eventlog registry key to IT operations?

Background Many developers are unnecessarily lowering the security of the event log, or requiring applications to run in Administrator mode just so they can use the event log with this C# or VB code: ...
0
votes
1answer
701 views

When should one use RSACryptoServiceProvider vs AESCryptoServiceProvider

I am interested in storing certificates for various purposes on a SmartCard. Since this answer illustrates how there are confusing differences and similarities between RSA and AES When should one ...
13
votes
7answers
6k views

What are the realistic, and most secure crypto for Symmetric, Asymmetric, Hash, Message Authentication Code ciphers?

I'm interested in updating this two pronged question for 2011: What cryptology is most appropriate for low-powered devices (such as a cellphone), and yet still effective? What cryptology is most ...
12
votes
6answers
7k views

Is PBKDF2-based System.Cryptology.RFC2898DeriveBytes() “better” for Unicode Password hashing than traditional methods?

When is it appropriate to use RFC2898DeriveBytes versus a typical hash? Update I now understand that a KDF is typically used to create a symmetric key for possible use in encrypting a stream. I ...
3
votes
2answers
1k views

Secure communication between C# client and Java server, using certificates

I want to secure communication between simple C# WPF client and Java server. Now i have already implemented raw sockets communication, and my security is based on: server send RSA public key to ...
3
votes
1answer
753 views

How to use DPAPI under load balance environment

DPAPI can be used to encrypt the secret data. We intend to use it in our web app to encrypt some data and store the encrypted data in database. When needed we decrypt the data and present them on ...
4
votes
4answers
5k views

Reflector - obfuscated code

I run Reflector to de-compile some program and it seems to be obfuscated. I got following output, it’s not very useful. Any ideas how to decompile obfuscated code? [CompilerGenerated] get ...
4
votes
2answers
2k views

How to store IV and key temporarily but securely

I am using .NET 4.0 to develop a Windows service that will temporarily store encrypted data in a database. The data will be encrypted when it is inserted, then decrypted, processed, and deleted once ...
6
votes
2answers
2k views

C# Image.FromStream is that secure?

after reading the data from the request as Stream i needed to convert it to Image so i used this Method: Stream inputStream = HttpContext.Current.Request.InputStream; Image img = ...
3
votes
1answer
349 views

Does strong naming remove the need for packing/obfuscation?

I'm new to .NET programming, and I'm wondering - from a security perspective - whether the strong naming scheme used in .NET assemblies completely removes the need for other commonly used techniques ...
2
votes
1answer
651 views

Are .NET WebServices vulnerable to CSRF?

While developing TeamMentor I implemented a number of WebServices (consumed via jQuery) and now on its final push for release I want to double check that they are not vulnerable to CSRF. There isn't ...
2
votes
3answers
415 views

What are the best security practices to install a C# Web App on client servers?

We would like to install a Web App written in C#/.NET4 on client servers, not ours. I would like to know what are the best security practices to implement for avoid the following: Authority ...
0
votes
1answer
1k views

windows security alert windows firewall has blocked some features of this program message coming for every new build of my application

I made an application which uses ftp so windows shows windows security alert windows firewall has blocked some features of this program message for every new version of my application any idea how to ...
2
votes
2answers
766 views

C# Encrypting string in DES 3 CBC mode

Is it normal that when I use Double DES secret key to encrypt a string in DES3 CBC mode then I always get the same cipher text? For testing I'm using IVC=0.
2
votes
3answers
145 views

Identifying and preventing execution of “any” function via Late-Bound commands

The Command Pattern is widely used to create a robust, salable applications. However I see guidance in this MSDN article that could allow a caller to invoke a late-bound command... enabling the ...