PureBasic Requires Chilkat v11.0.0+
PureBasic
RSASSA-PSS Sign Text
Signs text to create a PKCS7/CMS signature. The signature algorithm is RSASSA-PSS with SHA256.Chilkat PureBasic Downloads
IncludeFile "CkCert.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkPfx.pb"
IncludeFile "CkCrypt2.pb"
Procedure ChilkatExample()
success.i = 0
; This example requires the Chilkat API to have been previously unlocked.
; See Global Unlock Sample for sample code.
crypt.i = CkCrypt2::ckCreate()
If crypt.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
; 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.)
pfx.i = CkPfx::ckCreate()
If pfx.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkPfx::ckLoadPfxFile(pfx,"qa_data/rsassa-pss/privatekey.pfx","PFX_PASSWORD")
If success = 0
Debug CkPfx::ckLastErrorText(pfx)
CkCrypt2::ckDispose(crypt)
CkPfx::ckDispose(pfx)
ProcedureReturn
EndIf
; 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.)
cert.i = CkCert::ckCreate()
If cert.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkPfx::ckCertAt(pfx,0,cert)
If success = 0
Debug CkPfx::ckLastErrorText(pfx)
CkCrypt2::ckDispose(crypt)
CkPfx::ckDispose(pfx)
CkCert::ckDispose(cert)
ProcedureReturn
EndIf
CkCrypt2::ckSetSigningCert(crypt,cert)
; Indicate that RSASSA-PSS with SHA256 should be used.
CkCrypt2::setCkSigningAlg(crypt, "pss")
CkCrypt2::setCkHashAlgorithm(crypt, "sha256")
CkCrypt2::setCkEncodingMode(crypt, "base64_mime")
; Build a string to sign
sb.i = CkStringBuilder::ckCreate()
If sb.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
i.i = 1
While i < 12
CkStringBuilder::ckAppendInt(sb,i)
CkStringBuilder::ckAppend(sb," the quick brown fox jumped over the lazy dog." + Chr(13) + Chr(10))
i = i + 1
Wend
Debug CkStringBuilder::ckGetAsString(sb)
; 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)
CkCrypt2::setCkCharset(crypt, "utf-8")
; Sign the string to get a PKCS7 detached signature in base64 format.
pkcs7sig.s = CkCrypt2::ckSignSbENC(crypt,sb)
Debug "Detached PCKS7 Signature:"
Debug pkcs7sig
; 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:
success = CkCrypt2::ckVerifySbENC(crypt,sb,pkcs7sig)
Debug "Signature verified: " + Str(success)
CkCrypt2::ckDispose(crypt)
CkPfx::ckDispose(pfx)
CkCert::ckDispose(cert)
CkStringBuilder::ckDispose(sb)
ProcedureReturn
EndProcedure