Tcl Requires Chilkat v11.0.0+

Generate a CSR with keyUsage, extKeyUsage, and other Extensions

See more CSR Examples

Demonstrates how to generate a CSR containing a 1.2.840.113549.1.9.14 extensionRequest with the following extensions:

• 1.3.6.1.4.1.311.20.2 enrollCerttypeExtension
• 2.5.29.15 keyUsage
• 2.5.29.37 extKeyUsage
• 2.5.29.14 subjectKeyIdentifier

Tcl

load ./chilkat.dll

set success 0

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

#  This example will generate a secp256r1 ECDSA key for the CSR.
set ecc [new_CkEcc]

set prng [new_CkPrng]

set privKey [new_CkPrivateKey]

set success [CkEcc_GenKey $ecc "secp256r1" $prng $privKey]
if {$success == 0} then {
    puts "Failed to generate a new ECDSA private key."
    delete_CkEcc $ecc
    delete_CkPrng $prng
    delete_CkPrivateKey $privKey
    exit
}

set csr [new_CkCsr]

#  Add common CSR fields:
CkCsr_put_CommonName $csr "mysubdomain.mydomain.com"
CkCsr_put_Country $csr "GB"
CkCsr_put_State $csr "Yorks"
CkCsr_put_Locality $csr "York"
CkCsr_put_Company $csr "Internet Widgits Pty Ltd"
CkCsr_put_EmailAddress $csr "support@mydomain.com"

#  Add the following 1.2.840.113549.1.9.14 extensionRequest
#  Note: The easiest way to know the content and format of the XML to be added is to examine
#  a pre-existing CSR with the same desired extensionRequest.  You can use Chilkat to
#  get the extensionRequest from an existing CSR. 

#  Here is a sample extension request:

#  <?xml version="1.0" encoding="utf-8"?>
#  <set>
#      <sequence>
#          <sequence>
#              <oid>1.3.6.1.4.1.311.20.2</oid>
#              <asnOctets>
#                  <universal tag="30" constructed="0">AEUAbgBkAEUAbgB0AGkAdAB5AEMAbABpAGUAbgB0AEEAdQB0AGgAQwBlAHIAdABpAGYAaQBjAGEAdABl
#  AF8AQwBTAFIAUABhAHMAcwB0AGgAcgBvAHUAZwBoAC8AVgAx</universal>
#              </asnOctets>
#          </sequence>
#          <sequence>
#              <oid>2.5.29.15</oid>
#              <bool>1</bool>
#              <asnOctets>
#                  <bits n="3">A0</bits>
#              </asnOctets>
#          </sequence>
#          <sequence>
#              <oid>2.5.29.37</oid>
#              <asnOctets>
#                  <sequence>
#                      <oid>1.3.6.1.5.5.7.3.3</oid>
#                  </sequence>
#              </asnOctets>
#          </sequence>
#          <sequence>
#              <oid>2.5.29.14</oid>
#              <asnOctets>
#                  <octets>MCzBMQAViXBz8IDt8LsgmJxJ4Xg=</octets>
#              </asnOctets>
#          </sequence>
#      </sequence>
#  </set>

#  Use this online tool to generate code from sample XML: 
#  Generate Code to Create XML

#  A few notes:
#  The string "AEUAbgBkAEUAbgB0AGkAdAB5AEMAbABpAGUAbgB0AEEAdQB0AGgAQwBlAHIAdABpAGYAaQBjAGEAdABlAF8AQwBTAFIAUABhAHMAcwB0AGgAcgBvAHUAZwBoAC8AVgAx"
#  is the base64 encoding of the utf-16be byte representation of the string "EndEntityClientAuthCertificate_CSRPassthrough/V1"

set s "EndEntityClientAuthCertificate_CSRPassthrough/V1"
set bdTemp [new_CkBinData]

CkBinData_AppendString $bdTemp $s "utf-16be"
set s_base64_utf16be [CkBinData_getEncoded $bdTemp "base64"]
#  The string should be "AEUA....."
puts "$s_base64_utf16be"

#  Here's the code to generate the above extension request.

set xml [new_CkXml]

CkXml_put_Tag $xml "set"
CkXml_UpdateChildContent $xml "sequence|sequence|oid" "1.3.6.1.4.1.311.20.2"
CkXml_UpdateAttrAt $xml "sequence|sequence|asnOctets|universal" 1 "tag" "30"
CkXml_UpdateAttrAt $xml "sequence|sequence|asnOctets|universal" 1 "constructed" "0"
CkXml_UpdateChildContent $xml "sequence|sequence|asnOctets|universal" $s_base64_utf16be
CkXml_UpdateChildContent $xml "sequence|sequence[1]|oid" "2.5.29.15"
CkXml_UpdateChildContent $xml "sequence|sequence[1]|bool" "1"
CkXml_UpdateAttrAt $xml "sequence|sequence[1]|asnOctets|bits" 1 "n" "3"
#  A0 is hex for decimal 160.
CkXml_UpdateChildContent $xml "sequence|sequence[1]|asnOctets|bits" "A0"
CkXml_UpdateChildContent $xml "sequence|sequence[2]|oid" "2.5.29.37"
CkXml_UpdateChildContent $xml "sequence|sequence[2]|asnOctets|sequence|oid" "1.3.6.1.5.5.7.3.3"

#  This is the subjectKeyIdentifier extension.
#  The string "MCzBMQAViXBz8IDt8LsgmJxJ4Xg=" is base64 that decodes to 20 bytes, which is a SHA1 hash.
#  This is simply a hash of the DER of the public key.

set pubKey [new_CkPublicKey]

CkPrivateKey_ToPublicKey $privKey $pubKey
set bdPubKeyDer [new_CkBinData]

CkBinData_AppendEncoded $bdPubKeyDer [CkPublicKey_getEncoded $pubKey 1 "base64"] "base64"
set ski [CkBinData_getHash $bdPubKeyDer "sha1" "base64"]

CkXml_UpdateChildContent $xml "sequence|sequence[3]|oid" "2.5.29.14"
CkXml_UpdateChildContent $xml "sequence|sequence[3]|asnOctets|octets" $ski

#  Add the extension request to the CSR
CkCsr_SetExtensionRequest $csr $xml

#  Generate the CSR with the extension request
set csrPem [CkCsr_genCsrPem $csr $privKey]
if {[CkCsr_get_LastMethodSuccess $csr] == 0} then {
    puts [CkCsr_lastErrorText $csr]
    delete_CkEcc $ecc
    delete_CkPrng $prng
    delete_CkPrivateKey $privKey
    delete_CkCsr $csr
    delete_CkBinData $bdTemp
    delete_CkXml $xml
    delete_CkPublicKey $pubKey
    delete_CkBinData $bdPubKeyDer
    exit
}

puts "$csrPem"

delete_CkEcc $ecc
delete_CkPrng $prng
delete_CkPrivateKey $privKey
delete_CkCsr $csr
delete_CkBinData $bdTemp
delete_CkXml $xml
delete_CkPublicKey $pubKey
delete_CkBinData $bdPubKeyDer