I want to decrypt an document with the matching private key under Windows high security conditions. But everytime the CSP asks for the password to grant access.
I need to suppress the password dialog and insert the password programmatically.
I have installed the X509 software certificate in certificate store under high security conditions. I fetched it as X509Certificates2 from store, encryption works, decryption works but password dialog appears. How can I set the password beforehand, so that it is already known by CSP and the access to private key operations will be granted, without password dialog?
I tried following steps:
1. Encryption with x509 software certificate (public key)
The x509 certificate (cert) has been importet from the certificate store
2. Decryption with x509 software certificate (private key)
Public Function EncryptWithCertPubKey(cert As System.Security.Cryptography.X509Certificates.X509Certificate2, data As Byte()) As Byte()
Dim rsa As System.Security.Cryptography.RSACryptoServiceProvider = TryCast(cert.PublicKey.Key, System.Security.Cryptography.RSACryptoServiceProvider)
Return rsa.Encrypt(data, True)
The password (certPass) was set when installing the certificate into the certificate store under high security conditions.
The export to raw data seemed to be a way to do this and simutanously put in the password for suppressing the dialog.
But again the password dialog appears while accessing the private key when exporting, event though the pass is given already.
Public Function DecryptWithCertKey(cert As System.Security.Cryptography.X509Certificates.X509Certificate2, certPass As String, data As Byte()) As Byte()
Dim rawdata As Byte() = cert.Export(Security.Cryptography.X509Certificates.X509ContentType.Pkcs12, certPass)
Dim cert2 As New System.Security.Cryptography.X509Certificates.X509Certificate2(rawdata, certPass)
Dim rsa2 As System.Security.Cryptography.RSACryptoServiceProvider = TryCast(cert2.PrivateKey, System.Security.Cryptography.RSACryptoServiceProvider)
Return rsa2.Decrypt(data, True)
I found out that there is a Function in CSP-Parameters to preset the Password, so it should be already known for the CSP, and no dialog might appear if it works.
But I don't know how to handle it, because I have'nt found a way to insert CSP-Parameters to X509Certificates2, neither to RSACryptoprovider (while using X509Certificates2).
Dim certPass As New System.Security.SecureString
Dim cspp As New System.Security.Cryptography.CspParameters(1, "Microsoft Strong Cryptographic Provider")
cspp.KeyPassword = certPass
Any help is appreciated.