Delphi DLL Requires Chilkat v11.0.0+

HTTPS Server Certificate Require Hostname Match

See more HTTP Examples

Demonstrates and explains the RequireHostnameMatch property. Delphi DLL

var
http: HCkHttp;
html: PWideChar;

begin
//  The RequireHostnameMatch property was added in Chilkat v11.0.0
//  to ensure the URL's hostname matches at least one of the server certificate SAN's (Subject Alternative Names)
//  
//  In actuality, it is the SNI hostname that must match.  If the SNI hostname is not explicitly set,
//  then Chilkat uses the hostname from the URL as the SNI hostname.

//  Here's an example using chilkatsoft.com
//  The SSL server certificate for chilkatsoft.com has 2 Subject Alternative Names:
//  
//  1) DNS Name: *.chilkatsoft.com
//  2) DNS Name: chilkatsoft.com
//  
//  See Explaining the SNI Hostname in TLS

http := CkHttp_Create();

CkHttp_putRequireHostnameMatch(http,True);

//  This should succeed because "www.chilkatsoft.com" matches the SAN entry "*.chilkatsoft.com"
html := CkHttp__quickGetStr(http,'https://www.chilkatsoft.com/helloWorld.html');
Memo1.Lines.Add('1) Succeeded: ' + IntToStr(Ord(CkHttp_getLastMethodSuccess(http))));

//  At the time of writing this example, the IP address for chilkatsoft.com is 3.101.18.47
//  If we send the request using the IP address, it will fail because the IP address is does 
//  not match any of the SAN entries in the server certificate.
html := CkHttp__quickGetStr(http,'https://3.101.18.47/helloWorld.html');
Memo1.Lines.Add('2) Succeeded: ' + IntToStr(Ord(CkHttp_getLastMethodSuccess(http))));

//  However, it will succeed if we explicitly set the SNI hostname.
CkHttp_putSniHostname(http,'www.chilkatsoft.com');
html := CkHttp__quickGetStr(http,'https://3.101.18.47/helloWorld.html');
Memo1.Lines.Add('3) Succeeded: ' + IntToStr(Ord(CkHttp_getLastMethodSuccess(http))));

//  Remove our explicit SNI hostname.
CkHttp_putSniHostname(http,'');

//  Now let's try wrong.host.badssl.com
//  The SSL server certificate for badssl.com has 2 Subject Alternative Names:
//  
//  1) DNS Name: *.badssl.com
//  2) DNS Name: badssl.com

//  The domain wrong.host.badssl.com will fail the RequireHostnameMatch because
//  the wildcarded domain SAN entry only extends 1 level deep.  
html := CkHttp__quickGetStr(http,'https://wrong.host.badssl.com/');
Memo1.Lines.Add('4) Succeeded: ' + IntToStr(Ord(CkHttp_getLastMethodSuccess(http))));

//  The expected output is:
//  1) Succeeded: True
//  2) Succeeded: False
//  3) Succeeded: True
//  4) Succeeded: False

CkHttp_Dispose(http);