Thursday, 14 July 2011

Create PFX with the Asymmetric keys genereated during CSR phase

This will not work with CNG(KSP)

Steps 1

1. When we create key/pair, store the KeyContainerName.
2. Sign CSR with created keys and get the certificate(one of CER/DER/PEM/CRT) format.
3. Open the certificate using x509certificate2 class, create CspParameter class. Assign the KeyContainerName to CspParamater class.
4. Create RsaCryptoProvider class using CspParamater, and assign it to PrivateKey of x509certificate2.
5. Using Export(pfx, password) option.
6. Clear RsaCryptoProvider using PersistCsp = false, and Clear().

Note
1. If you don't pass valid KeyContainerName, default will be created. But assigning to PrivateKey property will throw exception about Key mismatch(after all they are strongly related).
2. Clear the KeyContainer for better security purposes.

Sample code to get u started.

CspParameters p = new CspParameters();

p.ProviderName = "Microsoft Enhanced Cryptographic Provider v1.0";
p.ProviderType = 1;
p.KeyContainerName = "your container name";
p.KeyNumber = (int)AT_KEYEXCHANGE;

RSACryptoServiceProvider csp = new RSACryptoServiceProvider(p);

X509Certificate2 cer = new X509Certificate2("sss.cer");

cer.PrivateKey = csp;

byte[] bytes = cer.Export(X509ContentType.Pfx, "12345");

FileStream stream = new FileStream("CASigned.pfx", FileMode.CreateNew);

stream.Write(bytes, 0, bytes.Length);

stream.Close();

X509Certificate2 c1 = new X509Certificate2("CASigned.pfx", "12345");

bool value = c1.HasPrivateKey;

Wednesday, 13 July 2011

Certificate file types

Two types of encoding used in certificate

1. DER(Distinguished Encoding Rule) - DER encoded certificate.
2. PEM - Base64 encoded certificate - starts with BEGIN CERTIFICATE and ends with END CERTIFICATE.

Above can also used and extensions.

Common extensions
-----------------

1. CRT - Most common among *nix systems
2. CER - alternate form of .CRT (Microsoft Convention)

The only time CRT and CER can safely be interchanged is when the encoding type can be identical. (ie PEM encoded CRT = PEM encoded CER)

Monday, 4 July 2011

Respecting windows UAC while using LsaOpenPolicy

Please use POLICY_VIEW_LOCAL_INFORMATION = 1;

so your code will become

LsaOpenPolicy(SystemName, ref LSA_OBJECT_ATTRIBUTES,
(int)POLICY_VIEW_LOCAL_INFORMATION, out IntPtr)

Friday, 10 June 2011

Wix force install new msi

msiexec caches the installer, hence if you want to force executing new installer pls use

msiexec /fc installer.msi

This might be useful, because while developing you might have set installation conditions wrong, which might fire during un-installation as well, hence might block from doing so.

like




Above condition happens no matter what whether you are trying to install or uninstall.

Thursday, 13 August 2009

PerCall - No Session - It is all confusing

http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/0739e712-2abe-4b10-8667-3de5c43e4552

Spring.Net - AutoProxy

AutoProxy is an important technique offered by Spring.Net. Read below forum discussion

http://forum.springframework.net/showthread.php?t=5655

AutoMapper

Disclaimer - I have been using AutoMapper only for two weeks, so i might be wrong here

So, This tool avoid lot of pain from writing mapping codes. But being said that it is not a mature tool and will be a pain in butt incase of even medium level hierarchies.

With the verion 0.3.1(from Code plex),

1. You can't use abstract relation ship - though r116(latest as of now) solves this problem. What i mean here is

If you map 'Dog' to 'Dog' with a code like .Map(new Source.Dog()), it fails.

But if Source.Animal is interface, then it works. What crap?

2. Not perfect with collections(r116)

But being said that, if you have classes with simple/no relationship, this is a great tool.