(DataFlex) RSA Encrypt RSA/ECB/OAEPWithSHA1AndMGF1Padding

Demonstrates how to RSA encrypt using RSA/ECB/OAEPWithSHA1AndMGF1Padding. Also demonstrates RSA/ECB/OAEPWithSHA-256AndMGF1Padding. Both of these terms are from Java's JCE. Note: In this context, "ECB" doesn't actually mean anything. It's a symmetric cipher mode that doesn't apply (or make sense) in this context.

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

Use ChilkatAx-9.5.0-win32.pkg

Procedure Test
    Handle hoRsa
    Variant vPubkey
    Handle hoPubkey
    Boolean iSuccess
    String sPlainText
    Boolean iUsePrivateKey
    String sEncryptedStr
2    Handle hoRsa2
    Variant vPrivKey
    Handle hoPrivKey
    String sOriginalStr
    String sTemp1

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    Get Create (RefClass(cComChilkatRsa)) To hoRsa
    If (Not(IsComObjectCreated(hoRsa))) Begin
        Send CreateComObject of hoRsa
    End

    // First load a public key object with a public key.
    // In this case, we'll load it from a file.
    Get Create (RefClass(cComChilkatPublicKey)) To hoPubkey
    If (Not(IsComObjectCreated(hoPubkey))) Begin
        Send CreateComObject of hoPubkey
    End
    Get ComLoadFromFile Of hoPubkey "qa_data/pem/rsa_public.pem" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoPubkey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // RSA encryption is limited to small amounts of data. The limit
    // is typically a few hundred bytes and is based on the key size and
    // padding (OAEP vs. PKCS1_5).  RSA encryption is typically used for
    // encrypting hashes or symmetric (bulk encryption algorithm) secret keys.
    Move "Time is an illusion. Lunchtime doubly so." To sPlainText

    // Import the public key to be used for encrypting.
    Get pvComObject of hoPubkey to vPubkey
    Get ComImportPublicKeyObj Of hoRsa vPubkey To iSuccess

    // To get OAEP padding, set the OaepPadding property:
    Set ComOaepPadding Of hoRsa To True

    // To use SHA1 or SHA-256, set the OaepHash property
    Set ComOaepHash Of hoRsa To "sha256"
    // for SHA1 --
    Set ComOaepHash Of hoRsa To "sha1"

    // Indicate we'll want hex output
    Set ComEncodingMode Of hoRsa To "hex"

    // Encrypt..
    Move False To iUsePrivateKey
    Get ComEncryptStringENC Of hoRsa sPlainText iUsePrivateKey To sEncryptedStr
    Showln sEncryptedStr

    // -------------------------------------------------
    // Now decrypt with the matching private key.
    Get Create (RefClass(cComChilkatRsa)) To hoRsa2
    If (Not(IsComObjectCreated(hoRsa2))) Begin
        Send CreateComObject of hoRsa2
    End

    Get Create (RefClass(cComChilkatPrivateKey)) To hoPrivKey
    If (Not(IsComObjectCreated(hoPrivKey))) Begin
        Send CreateComObject of hoPrivKey
    End
    Get ComLoadEncryptedPem Of hoPrivKey "qa_data/pem/rsa_passwd.pem" "passwd" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoPrivKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get pvComObject of hoPrivKey to vPrivKey
    Get ComImportPrivateKeyObj Of hoRsa2 vPrivKey To iSuccess

    // Make sure we have the same settings used for encryption.
    Set ComOaepPadding Of hoRsa2 To True
    Set ComEncodingMode Of hoRsa2 To "hex"
    Set ComOaepHash Of hoRsa2 To "sha1"

    Get ComDecryptStringENC Of hoRsa2 sEncryptedStr True To sOriginalStr

    Showln sOriginalStr


End_Procedure