Lianja

Create PEM-encoded PKCS#7 Detached Signature

See more Digital Signatures Examples

Demonstrates how to create a PKCS7 PEM-encoded object containing a detached signature. Lianja

llSuccess = .F.

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

loCert = createobject("CkCert")

// Load the cert and private key.
llSuccess = loCert.LoadPfxFile("qa_data/pfx/myCertAndKey.p12","password")
if (llSuccess <> .T.) then
    ? loCert.LastErrorText
    release loCert
    return
endif

loCrypt = createobject("CkCrypt2")

llSuccess = loCrypt.SetSigningCert(loCert)
if (llSuccess <> .T.) then
    ? loCrypt.LastErrorText
    release loCert
    release loCrypt
    return
endif

// Use SHA-256
loCrypt.HashAlgorithm = "sha256"

// Hash the utf-8 byte representation of the string
loCrypt.Charset = "utf-8"

// Return the result in base64
loCrypt.EncodingMode = "base64Mime"

// Sign some text to create a detached signature (i.e. a signature that does not include the signed data)
lcTextToSign = "This is the text to be hashed and signed."
lcSigBase64 = loCrypt.SignStringENC(lcTextToSign)
if (loCrypt.LastMethodSuccess <> .T.) then
    ? loCrypt.LastErrorText
    release loCert
    release loCrypt
    return
endif

? lcSigBase64

// The result:

// MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
// ...
// ...

// If we want it in PEM format with just LF line-endings:
loSb = createobject("CkStringBuilder")
// Just LF line endings, not CRLF.
llCrlf = .F.
loSb.AppendLine("-----BEGIN PKCS7-----",llCrlf)
loSb.Append(lcSigBase64)
loSb.AppendLine("-----END PKCS7-----",llCrlf)
loSb.ToLF()

// Save to a file.
loSb.WriteFile("c:/temp/qa_output/sig.pem","utf-8",.F.)

// Examine..
? loSb.GetAsString()

// Result is:

// -----BEGIN PKCS7-----
// MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
// ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
// DjAMBgNVBAcMBU1pbGFuMSMwIQYDVQQKDBpBY3RhbGlzIFMucC5BLi8wMzM1ODUyMDk2NzEnMCUG
// A1UEAwweQWN0YWxpcyBBdXRoZW50aWNhdGlvbiBSb290IENBMB4XDTExMDkyMjExMjIwMloXDTMw
// MDkyMjExMjIwMlowazELMAkGA1UEBhMCSVQxDjAMBgNVBAcMBU1pbGFuMSMwIQYDVQQKDBpBY3Rh
// bGlzIFMucC5BLi8wMzM1ODUyMDk2NzEnMCUGA1UEAwweQWN0YWxpcyBBdXRoZW50aWNhdGlvbiBS
// b290IENBMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAp8bEpSmkLO/lGMWwUKNvUTuf
// ClrJwkg4CsIcoBh/kbWHuUA/3R1oHwiD1S0eiKD4j1aPbZkCkpAW1V8IbInX4ay8IMKx4INRimlN
// AJZaby/ARH6jDuSRzVju3PvHHkVH3Se5CAGfpiEd9UEtL0z9KK3giq0itFZljoZUj5NDKd45Rnij
// MCO6zfB9E1fAXdKDa0hMxKufgFpbOr3JpyI/gCczWw63igxdBzcIy2zSekciRDXFzMwujt0q7bd9
// ...
// ...
// -----END PKCS7-----


release loCert
release loCrypt
release loSb