Clearing / resetting images in Outlook cache

While creating emails, quite a few times you will not see the updated images in the email. this is because Outlook caches the images. These images are displayed from the cache even for newer mails. To remove any files from cache in Windows (for Outlook 2010 and above) do the following.

1. Close Outlook.
2. Press "Windows+R". and type or paste the following:
   

   %USERPROFILE%\Local Settings\Temporary Internet Files\Content.Outlook

3. Delete all the files and folder in this location.
4. Open Outlook.

In Mac do the following:

1. Right-click (or control-click) your Exchange Inbox NHSD folder
2. Click Folder Properties
3. Click the General Tab
4. Click Empty Cache

ASP.Net | POST request in C# with content-type being x-www-form-urlencoded

The following code makes a POST request in C# with content-type being x-www-form-urlencoded:

HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
webRequest.Method = "POST";
webRequest.AllowAutoRedirect = true;
webRequest.Timeout = 20 * 1000;
webRequest.ContentType = "application/x-www-form-urlencoded";
webRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";
webRequest.UserAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36";

//write the data to post request
//Postdata : a=1&b=2&c=3
byte[] buffer = Encoding.Default.GetBytes(Postdata);
if (buffer != null)
{
     webRequest.ContentLength = buffer.Length;
     webRequest.GetRequestStream().Write(buffer, 0, buffer.Length);
}

HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();
Stream dataStream = response.GetResponseStream();
StreamReader reader = new StreamReader(dataStream);
string strResponse = reader.ReadToEnd();

OpenSSL | Creating Certification Authority & Domain Certificates for IIS

Setup

Download the OpenSSL binaries from this location.

(Please note that version 1.0.2 works better in windows)

Extract the binaries at location:

C:\OpenSSL\

The binaries will be downloaded in bin folder. Now create a demo folder at this location

Add the following location to windows PATH variable.

C:\OpenSSL\bin

Create 2 Environment Variables:

set RANDFILE=C:\OpenSSL\demo\.rnd
set OPENSSL_CONF=C:\OpenSSL\bin\openssl.cfg

Open Command Prompt and type openssl. You should get a window like this:

This means that the setup is correct and complete. Else fix your windows PATH variable. Close this window.

Create a Root Certification Authority

Now we need to create a certificate for Root Certification Authority. Open Command Prompt and change location to demo folder using command:

cd C:\OpenSSL\demo

Create key as (location: C:\OpenSSL\demo):

openssl genrsa -out RootCA.key 4096

Use this key to create a Root Certificate using command:

openssl req -new -x509 -days 7300 -key RootCA.key -out RootCA.crt

The certificate expiration is set to 20 years (7300 days). Change to match your requirements.

You will have to enter details as:

The certificate name is the input entered against field: Common Name

Please note that if you press enter without entering a value, the default value (value displayed in []) will be used to create certificate. The certificate RootCA.crt will be created at location:

C:\OpenSSL\demo

This certificate will have to be installed in Trusted Root Certification Authority in any machine which the website is installed or used.

Create a Domain Certificate

Now we need to create a domain certificate. Create a folder contoso at location:

C:\OpenSSL\demo

Create a file csr_detail.cnf using the details below in contoso folder:

[req]
distinguished_name = req_distinguished_name
req_extensions = v3_req

[req_distinguished_name]
countryName = US
countryName_default = US
stateOrProvinceName = New York
stateOrProvinceName_default = NY
localityName = New York
localityName_default = New York
organizationalUnitName = Contoso Unit
organizationalUnitName_default = Contoso Unit
commonName = contoso.com
commonName_default = contoso.com
organizationName = Contoso
organizationName_default = Contoso
commonName_max  = 64

[ v3_req ]
# Extensions to add to a certificate request
basicConstraints = CA:FALSE
keyUsage = nonRepudiation, digitalSignature, keyEncipherment
subjectAltName = @alt_names

[alt_names]
DNS.1 = www.contoso.com
DNS.2 = files.contoso.com
IP.1 = 0.0.0.0

Edit it to match your needs.

Open Command Prompt and change location to contoso folder using command:

cd C:\OpenSSL\demo\contoso 

Create a KEY for the certificate using the command:

openssl genrsa -out contoso.com.key 2048

Create a CSR file for the certificate using the command:

openssl req -new -out contoso.com.csr -key contoso.com.key -config csr_details.cnf

You will be asked to input fields as:

Press enter in each field to add default value already set from CNF file.


Create a certificate using the CNF file, KEY and the CSR file using the command:

openssl x509 -req -days 3650 -in contoso.com.csr -CA ..\RootCA.crt -CAkey ..\RootCA.key -set_serial 01  -extensions v3_req -extfile csr_details.cnf -out contoso.com.crt

This certificate will be created as contoso.com.crt at location:

C:\OpenSSL\demo\contoso

Now we need to create a PFX file so that this certificate can be imported in IIS. Use the following command:

openssl pkcs12 -export -out contoso.com.pfx -inkey contoso.com.key -in contoso.com.crt

You will be asked to enter a password (at least 4 characters) as:

Import this PFX file in IIS and use it in both the domains: www.contoso.com & files.contoso.com