Surprise, it's me again! Today I have finished network share management module for PowerShell. I want to thank Shay Levy who helped me with module-related stuff.

With this module you will be able to:

• List share (or shares) from local or from remote computers;
• Create new share with various settings;
• Remove share (actually this not remove folder itself, but stops sharing);
• Add/Set/Remove share permissions (note that share permissions and NTFS rights are not the same).

Here are module installation instructions:

Update 04.08.2018: clarified behavior on timestamping certificate revocation

Hello again! Today I would like to discuss about digital signatures and signature usage questions.

A very short introduction to digital signatures

As you know the signature guarantees that the electronic document wasn't changed after signing process. This is a useful feature for sensitive data that may be changed during transfer over network. For example, Internet. There is one well-known attack named Man In The Middle (MITM). In MITM, malicious user intercepts document change some data and transfer to the original recipient. If the document is originally signed (by sender) the recipient will attempt to validate document signature and will see that the document was changed during data transmission. This would invalidate the document.

In real world digital signatures are used very often and use asymmetric encryption/decryption processes.

Update 22.10.2017: updated use-case recommendations based on best practices.

Update 27.06.2018: added commands

In this article I will discuss about Root CA certificate renewal with new and existing key pair. At first we discuss about CA certificate renewal with existing key pair.

Renewal with existing key pair

When you renew CA certificate with existing key pair, nothing important in certificate is changed. The certificate will contain the same public and private key. As the result all previously issued certificates will chain up to new CA cert without any changes. You just replace old CRT file in AIA download locations. In addition, new CA cert ValidFrom (NotBefore) field will contain the value when existing CA key pair was generated. For example, old CA cert has ValidFrom (NotBefore) = 08.10.2000 and ValidTo (NotAfter) 08.10.2010. When you renew CA cert with existing key pair new certificate will have following values: ValidFrom (NotBefore) 08.10.2000 and ValidTo (NotAfter) 08.10.2020. In other words this renewal just increases current CA certificate validity period. In addition new CA cert introduces one new extension: Preious CA certificate hash that will contains preious certificate Thumbprint extension value. And changes another extension: CA Version. Let's take a look to a CA Version extension.

This is a new cmdlet for Exchange Server 2010 SP1. The cmdlet has FileData parameter that accepts certificate raw data in DER encoded format (byte array). However you will encounter an issue in the case when you have a certificate encoded in Base64. This is not an issue for PFX files because Pkcs12 don't support Base64 encoding, but other certificate file types (CER/Pkcs7/SST) support this. And if you have certificate encoded in Base64 you will get error. Let's see why. Here is an example of Base64-encoded certificate:

Recently someone asked a question about how to remove unused certificate stores. GUI and .NET don't provide this functionality (within X509Store class) and you will have to use other things. New Quest AD PKI cmdlets adds some features for certificate stores:

• Review certificate store

Get-QADLocalCertificateStore -StoreLocation CurrentUser
Get-QADLocalCertificateStore -StoreLocation LocalMachine

these commands can be used to explore available certificate containers in CurrentUser and LocalMachine store location. In addition these commands can be used to retrieve certificates from local stores as shown: