(SQL Server) RSA Decrypt using PEM

This example demonstrates decryping RSA encrypted data that is base64 encoded. It uses a private key loaded from a PEM file.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @rsa int
    -- Use "Chilkat_9_5_0.Rsa" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Rsa', @rsa OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @key int
    -- Use "Chilkat_9_5_0.PrivateKey" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.PrivateKey', @key OUT

    -- Load an RSA private key from an unencrypted PEM file:
    -- (To load from an encrypted PEM file, call LoadEncryptedPemFile instead.)

    DECLARE @success int
    EXEC sp_OAMethod @key, 'LoadPemFile', @success OUT, 'qa_data/rsa/decryptTest/priv.pem'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @key, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rsa
        EXEC @hr = sp_OADestroy @key
        RETURN
      END

    -- Make the key available to the RSA object
    EXEC sp_OAMethod @rsa, 'ImportPrivateKeyObj', @success OUT, @key
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @rsa, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rsa
        EXEC @hr = sp_OADestroy @key
        RETURN
      END

    DECLARE @encryptedStr nvarchar(4000)
    SELECT @encryptedStr = 'pP9XFJEsGgxPNHEgNiLB5H5ksCOXDk/G49BPTog1jKLAhYofV4UTH5k2TOYiqRnDnKs8+8uPoN/IxdiGXvuYG8HRzN0HtkhoZO/AxeyaB9S7eddCUlT0Pl2PEB2yQ9HG5rM7jqYOD6MAM4cuX7hqT8fa8tbzJzmBwdfFDBz94bwQjULHiO+gklIBC4vhkXT4yjuvEjxTAKU6tJeZYkBooJNdS/vE5RZRpuF6bGZU41Qc17qFR+iReBq+9f8IMmw8WR8fMbOCaygOfFS1nw7JVsIMGsAIXS8rUaJ/2DfGPfQx5HCiVtTOreGYRUI3esAQjnvUCnavZyQgs53nl7e2aA=='

    EXEC sp_OASetProperty @rsa, 'EncodingMode', 'base64'

    DECLARE @usePrivateKey int
    SELECT @usePrivateKey = 1
    DECLARE @decryptedStr nvarchar(4000)
    EXEC sp_OAMethod @rsa, 'DecryptStringENC', @decryptedStr OUT, @encryptedStr, @usePrivateKey


    PRINT 'Decrypted:'

    PRINT @decryptedStr

    EXEC @hr = sp_OADestroy @rsa
    EXEC @hr = sp_OADestroy @key


END
GO