Tcl

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. Tcl

load ./chilkat.dll

set success 0

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

set cert [new_CkCert]

# Load the cert and private key.
set success [CkCert_LoadPfxFile $cert "qa_data/pfx/myCertAndKey.p12" "password"]
if {$success != 1} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkCert $cert
    exit
}

set crypt [new_CkCrypt2]

set success [CkCrypt2_SetSigningCert $crypt $cert]
if {$success != 1} then {
    puts [CkCrypt2_lastErrorText $crypt]
    delete_CkCert $cert
    delete_CkCrypt2 $crypt
    exit
}

# Use SHA-256
CkCrypt2_put_HashAlgorithm $crypt "sha256"

# Hash the utf-8 byte representation of the string
CkCrypt2_put_Charset $crypt "utf-8"

# Return the result in base64
CkCrypt2_put_EncodingMode $crypt "base64Mime"

# Sign some text to create a detached signature (i.e. a signature that does not include the signed data)
set textToSign "This is the text to be hashed and signed."
set sigBase64 [CkCrypt2_signStringENC $crypt $textToSign]
if {[CkCrypt2_get_LastMethodSuccess $crypt] != 1} then {
    puts [CkCrypt2_lastErrorText $crypt]
    delete_CkCert $cert
    delete_CkCrypt2 $crypt
    exit
}

puts "$sigBase64"

# The result:

# MIIWbgYJKoZIhvcNAQcCoIIWXzCCFlsCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
# ghMXMIIFuzCCA6OgAwIBAgIIVwoRl0LE48wwDQYJKoZIhvcNAQELBQAwazELMAkGA1UEBhMCSVQx
# ...
# ...

# If we want it in PEM format with just LF line-endings:
set sb [new_CkStringBuilder]

# Just LF line endings, not CRLF.
set crlf 0
CkStringBuilder_AppendLine $sb "-----BEGIN PKCS7-----" $crlf
CkStringBuilder_Append $sb $sigBase64
CkStringBuilder_AppendLine $sb "-----END PKCS7-----" $crlf
CkStringBuilder_ToLF $sb

# Save to a file.
CkStringBuilder_WriteFile $sb "c:/temp/qa_output/sig.pem" "utf-8" 0

# Examine..
puts [CkStringBuilder_getAsString $sb]

# Result is:

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

delete_CkCert $cert
delete_CkCrypt2 $crypt
delete_CkStringBuilder $sb