DataFlex

RSASSA-PSS Sign Text

Signs text to create a PKCS7/CMS signature. The signature algorithm is RSASSA-PSS with SHA256. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoCrypt
    Handle hoPfx
    Variant vCert
    Handle hoCert
    Variant vSb
    Handle hoSb
    Integer i
    String sPkcs7sig
    String sTemp1

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatCrypt2)) To hoCrypt
    If (Not(IsComObjectCreated(hoCrypt))) Begin
        Send CreateComObject of hoCrypt
    End

    // Get a digital certificate with private key from a .pfx
    // (Chilkat has many different ways to provide a cert + private key for siging.
    // Using a PFX is just one possible option.)
    Get Create (RefClass(cComChilkatPfx)) To hoPfx
    If (Not(IsComObjectCreated(hoPfx))) Begin
        Send CreateComObject of hoPfx
    End
    Get ComLoadPfxFile Of hoPfx "qa_data/rsassa-pss/privatekey.pfx" "PFX_PASSWORD" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPfx To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the certificate to be used for signing.
    // (The typical case for a PFX is that it contains a cert with an associated private key,
    // as well as other certificates in the chain of authentication.  The cert with the private
    // key should be in the first position at index 0.)

    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End
    Get pvComObject of hoCert to vCert
    Get ComCertAt Of hoPfx 0 vCert To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPfx To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get pvComObject of hoCert to vCert
    Get ComSetSigningCert Of hoCrypt vCert To iSuccess

    // Indicate that RSASSA-PSS with SHA256 should be used.
    Set ComSigningAlg Of hoCrypt To "pss"
    Set ComHashAlgorithm Of hoCrypt To "sha256"

    Set ComEncodingMode Of hoCrypt To "base64_mime"

    // Build a string to sign
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSb
    If (Not(IsComObjectCreated(hoSb))) Begin
        Send CreateComObject of hoSb
    End
    Move 1 To i
    While (i < 12)
        Get ComAppendInt Of hoSb i To iSuccess
        Get ComAppend Of hoSb " the quick brown fox jumped over the lazy dog." + (character(13)) + (character(10)) To iSuccess
        Move (i + 1) To i
    Loop

    Get ComGetAsString Of hoSb To sTemp1
    Showln sTemp1

    // The string to be encrypted looks like this:

    // 1 the quick brown fox jumped over the lazy dog.
    // 2 the quick brown fox jumped over the lazy dog.
    // 3 the quick brown fox jumped over the lazy dog.
    // 4 the quick brown fox jumped over the lazy dog.
    // ...

    // Make sure to specify the byte representation (character encoding)
    Set ComCharset Of hoCrypt To "utf-8"

    // Sign the string to get a PKCS7 detached signature in base64 format.
    Get pvComObject of hoSb to vSb
    Get ComSignSbENC Of hoCrypt vSb To sPkcs7sig
    Showln "Detached PCKS7 Signature:"
    Showln sPkcs7sig

    // This signature looks like this:

    // MIIG5wYJKoZIhvcNAQcCoIIG2DCCBtQCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
    // ggL4MIIC9DCCAl2gAwIBAgIJAMPsJCT11cniMA0GCSqGSIb3DQEBCwUAMIGSMQswCQYDVQQGEwJB
    // VTERMA8GA1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8GA1UECgwYSW50ZXJu
    // ZXQgV2lkZ2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG9w0BCQEWGWFkbWlu
    // QGludGVybmV0d2lkZ2V0cy5jb20wHhcNMTYxMTAxMTY1MjMyWhcNMjExMDMxMTY1MjMyWjCBkjEL
    // MAkGA1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNV
    // BAoMGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcN
    // AQkBFhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKB
    // gQDGIdoCjyavs+F/Rm0VIB4m6O7VL1j+1IqieoR9NEX2GQvu2VCdceyxf9qaw1bxipEvjLwUkw7M
    // e+BTlLpWQbBMH87s6KpsC8MVyXhMLpP0oM8NFix/vLz2wdLhUh7CZvJA0plqkJk9bj57QIu+EO1k
    // tUHM2DFb6sckvCL2yybD1wIDAQABo1AwTjAdBgNVHQ4EFgQUONKKu2zsXIrinWxIGT654vrcQwsw
    // HwYDVR0jBBgwFoAUONKKu2zsXIrinWxIGT654vrcQwswDAYDVR0TBAUwAwEB/zANBgkqhkiG9w0B
    // AQsFAAOBgQArFvdi5u9i2QF1Qw+cdC1l7w2Y3+q6RIkln2W8rWJFje00644o8hXy7v46giJCedmF
    // ULlhm1n7XIsZGy2W3lJ77v5agn9gFwXu1h3cqkGXkoteE6SQJQXWgsW3GWPveObvTL8LF4y57fgM
    // 9ZWS+V9MJajeu44Rf/tU17TLYKjvEjGCA7MwggOvAgEBMIGgMIGSMQswCQYDVQQGEwJBVTERMA8G
    // A1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8GA1UECgwYSW50ZXJuZXQgV2lk
    // Z2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG9w0BCQEWGWFkbWluQGludGVy
    // bmV0d2lkZ2V0cy5jb20CCQDD7CQk9dXJ4jANBglghkgBZQMEAgEFAKCCAjQwGAYJKoZIhvcNAQkD
    // MQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTcwNDI5MTYzNTQ3WjAvBgkqhkiG9w0BCQQx
    // IgQgnXqtpfBjs9ZZUJxbNYbwYvpmXTGgIbYErkIA3jQo0EEwXwYJKoZIhvcNAQkPMVIwUDALBglg
    // hkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFAMAcGBSsO
    // AwIHMA0GCCqGSIb3DQMCAgEoMIGxBgkrBgEEAYI3EAQxgaMwgaAwgZIxCzAJBgNVBAYTAkFVMREw
    // DwYDVQQIDAhWaWN0b3JpYTESMBAGA1UEBwwJTWVsYm91cm5lMSEwHwYDVQQKDBhJbnRlcm5ldCBX
    // aWRnaXRzIFB0eSBMdGQxDzANBgNVBAMMBldpZGdldDEoMCYGCSqGSIb3DQEJARYZYWRtaW5AaW50
    // ZXJuZXR3aWRnZXRzLmNvbQIJAMPsJCT11cniMIGzBgsqhkiG9w0BCRACCzGBo6CBoDCBkjELMAkG
    // A1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNVBAoM
    // GEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcNAQkB
    // FhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tAgkAw+wkJPXVyeIwPQYJKoZIhvcNAQEKMDCgDTAL
    // BglghkgBZQMEAgGhGjAYBgkqhkiG9w0BAQgwCwYJYIZIAWUDBAIBogMCASAEgYBFgBS1vtBoac6P
    // /NRcY3jdytoxK7xc8vEYW/PhgsbE+sP7dvu6eoRLVicoQ8RIeMh3CtPZFq1+JcL5NNzQoAotizTX
    // EKhiceX1mC5ocCeEvgNouxkN2Qr/X12m60rNvNl5r+GEqiqx/1fs2yRAl5sIzwPsMMY3p9tGOpy0
    // 5p7sRQ==

    // The ASN.1 of the signature can be examined by browsing to https://lapo.it/asn1js/ ,
    // then copy-and-paste the Base64 signature into the form and decode..

    // The signature can be verified against the original data like this:
    Get pvComObject of hoSb to vSb
    Get ComVerifySbENC Of hoCrypt vSb sPkcs7sig To iSuccess
    Showln "Signature verified: " iSuccess


End_Procedure