DataFlex
DataFlex
Using the ASN.1 API to Create a Certificate Request (CSR)
See more ASN.1 Examples
Note: This example requires Chilkat v9.5.0.50 or greater.This example demonstrates how to use the Chilkat ASN.1 API to create a certificate signing request. The purpose of this example is to show, in general, how to use the ASN.1 methods to create an ASN.1 document and save to DER. There may be more concise ways of creating a CSR rather than using the lower-level ASN.1 methods presented here. The hope is that this example will enable developers to create many different kinds of ASN.1 structures/documents for which no other means exist.
This example will create ASN.1 having this structure and content:
Chilkat DataFlex Downloads
Use ChilkatAx-win32.pkg
Procedure Test
Boolean iSuccess
Handle hoAsnRoot
Variant vAsnCertReqInfo
Handle hoAsnCertReqInfo
Variant vAsnCertSubject
Handle hoAsnCertSubject
Variant vAsnTemp
Handle hoAsnTemp
Variant vAsnPubKeyInfo
Handle hoAsnPubKeyInfo
Variant vAsnPubKeyAlgId
Handle hoAsnPubKeyAlgId
Handle hoAsnRsaKey
String sRsaKeyDerBase64
Variant vAsnAlgId
Handle hoAsnAlgId
String sCsrBase64
Handle hoPem
String sTemp1
Move False To iSuccess
// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
Move False To iSuccess
// A new ASN.1 object is automatically a SEQUENCE.
// Given that the CSR's root item is a SEQUENCE, we can use
// this as the root of our CSR.
Get Create (RefClass(cComChilkatAsn)) To hoAsnRoot
If (Not(IsComObjectCreated(hoAsnRoot))) Begin
Send CreateComObject of hoAsnRoot
End
// Beneath the root, we have a SEQUENCE (the certificate request info),
// another SEQUENCE (the algorithm identifier), and a BITSTRING (this signature data)
Get ComAppendSequence Of hoAsnRoot To iSuccess
Get ComAppendSequence Of hoAsnRoot To iSuccess
Get ComAppendBits Of hoAsnRoot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hex" To iSuccess
// ----------------------------------
// Build the Certificate Request Info
// ----------------------------------
Get ComGetSubItem Of hoAsnRoot 0 To vAsnCertReqInfo
If (IsComObject(vAsnCertReqInfo)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnCertReqInfo
Set pvComObject Of hoAsnCertReqInfo To vAsnCertReqInfo
End
Get ComAppendInt Of hoAsnCertReqInfo 0 To iSuccess
// Build the Subject part of the Certificate Request Info
Get ComAppendSequenceR Of hoAsnCertReqInfo To vAsnCertSubject
If (IsComObject(vAsnCertSubject)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnCertSubject
Set pvComObject Of hoAsnCertSubject To vAsnCertSubject
End
// Add each subject part..
Get ComAppendSetR Of hoAsnCertSubject To vAsnTemp
If (IsComObject(vAsnTemp)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnTemp
Set pvComObject Of hoAsnTemp To vAsnTemp
End
Get ComAppendSequence2 Of hoAsnTemp To iSuccess
// AppendSequence2 updates the internal reference to the newly appended SEQUENCE.
// The OID and printable string are added to the SEQUENCE.
Get ComAppendOid Of hoAsnTemp "2.5.4.6" To iSuccess
Get ComAppendString Of hoAsnTemp "printable" "US" To iSuccess
Send Destroy of hoAsnTemp
Get ComAppendSetR Of hoAsnCertSubject To vAsnTemp
If (IsComObject(vAsnTemp)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnTemp
Set pvComObject Of hoAsnTemp To vAsnTemp
End
Get ComAppendSequence2 Of hoAsnTemp To iSuccess
Get ComAppendOid Of hoAsnTemp "2.5.4.8" To iSuccess
Get ComAppendString Of hoAsnTemp "utf8" "Utah" To iSuccess
Send Destroy of hoAsnTemp
Get ComAppendSetR Of hoAsnCertSubject To vAsnTemp
If (IsComObject(vAsnTemp)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnTemp
Set pvComObject Of hoAsnTemp To vAsnTemp
End
Get ComAppendSequence2 Of hoAsnTemp To iSuccess
Get ComAppendOid Of hoAsnTemp "2.5.4.7" To iSuccess
Get ComAppendString Of hoAsnTemp "utf8" "Lindon" To iSuccess
Send Destroy of hoAsnTemp
Get ComAppendSetR Of hoAsnCertSubject To vAsnTemp
If (IsComObject(vAsnTemp)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnTemp
Set pvComObject Of hoAsnTemp To vAsnTemp
End
Get ComAppendSequence2 Of hoAsnTemp To iSuccess
Get ComAppendOid Of hoAsnTemp "2.5.4.10" To iSuccess
Get ComAppendString Of hoAsnTemp "utf8" "DigiCert Inc." To iSuccess
Send Destroy of hoAsnTemp
Get ComAppendSetR Of hoAsnCertSubject To vAsnTemp
If (IsComObject(vAsnTemp)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnTemp
Set pvComObject Of hoAsnTemp To vAsnTemp
End
Get ComAppendSequence2 Of hoAsnTemp To iSuccess
Get ComAppendOid Of hoAsnTemp "2.5.4.11" To iSuccess
Get ComAppendString Of hoAsnTemp "utf8" "DigiCert" To iSuccess
Send Destroy of hoAsnTemp
Get ComAppendSetR Of hoAsnCertSubject To vAsnTemp
If (IsComObject(vAsnTemp)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnTemp
Set pvComObject Of hoAsnTemp To vAsnTemp
End
Get ComAppendSequence2 Of hoAsnTemp To iSuccess
Get ComAppendOid Of hoAsnTemp "2.5.4.3" To iSuccess
Get ComAppendString Of hoAsnTemp "utf8" "example.digicert.com" To iSuccess
Send Destroy of hoAsnTemp
Send Destroy of hoAsnCertSubject
// Build the Public Key Info part of the Certificate Request Info
Get ComAppendSequenceR Of hoAsnCertReqInfo To vAsnPubKeyInfo
If (IsComObject(vAsnPubKeyInfo)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnPubKeyInfo
Set pvComObject Of hoAsnPubKeyInfo To vAsnPubKeyInfo
End
Get ComAppendSequenceR Of hoAsnPubKeyInfo To vAsnPubKeyAlgId
If (IsComObject(vAsnPubKeyAlgId)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnPubKeyAlgId
Set pvComObject Of hoAsnPubKeyAlgId To vAsnPubKeyAlgId
End
Get ComAppendOid Of hoAsnPubKeyAlgId "1.2.840.113549.1.1.1" To iSuccess
Get ComAppendNull Of hoAsnPubKeyAlgId To iSuccess
Send Destroy of hoAsnPubKeyAlgId
// The public key itself is a BIT STRING, but the bit string is composed of ASN.1
// for the RSA public key. We'll first build the RSA ASN.1 for the public key
// (containing the 2048 bit modulus and exponent), and encoded it to DER, and then add
// the DER bytes as a BIT STRING (as a sub-item of asnPubKeyInfo)
// This is already a SEQUENCE..
Get Create (RefClass(cComChilkatAsn)) To hoAsnRsaKey
If (Not(IsComObjectCreated(hoAsnRsaKey))) Begin
Send CreateComObject of hoAsnRsaKey
End
// The RSA modulus is a big integer.
Get ComAppendBigInt Of hoAsnRsaKey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hex" To iSuccess
Get ComAppendInt Of hoAsnRsaKey 65537 To iSuccess
Get ComGetEncodedDer Of hoAsnRsaKey "base64" To sRsaKeyDerBase64
// Now add the RSA key DER as a BIT STRING.
Get ComAppendBits Of hoAsnPubKeyInfo sRsaKeyDerBase64 "base64" To iSuccess
Send Destroy of hoAsnPubKeyInfo
// The last part of the certificate request info is an empty context-specific constructed item
// with a tag equal to 0.
Get ComAppendContextConstructed Of hoAsnCertReqInfo 0 To iSuccess
Send Destroy of hoAsnCertReqInfo
// ----------------------------------
// Finally, add the algorithm identifier, which is the 2nd sub-item under the root.
// ----------------------------------
Get ComGetSubItem Of hoAsnRoot 1 To vAsnAlgId
If (IsComObject(vAsnAlgId)) Begin
Get Create (RefClass(cComChilkatAsn)) To hoAsnAlgId
Set pvComObject Of hoAsnAlgId To vAsnAlgId
End
Get ComAppendOid Of hoAsnAlgId "1.2.840.113549.1.1.5" To iSuccess
Get ComAppendNull Of hoAsnAlgId To iSuccess
Send Destroy of hoAsnAlgId
// Write the CSR to a DER encoded binary file:
Get ComWriteBinaryDer Of hoAsnRoot "qa_output/csr.der" To iSuccess
If (iSuccess <> True) Begin
Get ComLastErrorText Of hoAsnRoot To sTemp1
Showln sTemp1
Procedure_Return
End
// It is also possible to get the CSR in base64 format:
Get ComGetEncodedDer Of hoAsnRoot "base64" To sCsrBase64
Showln "Base64 CSR:"
Showln sCsrBase64
// To emit as PEM:
// (Note: The pem.AddItem method was added in Chilkat v9.5.0.59)
Get Create (RefClass(cComChilkatPem)) To hoPem
If (Not(IsComObjectCreated(hoPem))) Begin
Send CreateComObject of hoPem
End
Get ComAddItem Of hoPem "csr" "base64" sCsrBase64 To iSuccess
Showln "PEM:"
Get ComToPem Of hoPem To sTemp1
Showln sTemp1
End_Procedure