(PureBasic) Generate RSA Key and Export to PKCS1 / PKCS8

PureBasic example code showing how to generate an RSA public/private key and save to PKCS1 and PKCS8 format files. In a PKCS1 or PKCS8 formatted file, the key is stored in binary ASN.1 format (and ASN.1 is itself written according to DER -- Distinguished Encoding Rules). A PEM file simply contains the binary ASN.1 base64 encoded and delimited by BEGIN/END lines. PKCS1 format files are never encrypted. PKCS8 can be encrypted or unencrypted. Public keys are never encrypted (there is no need). Private keys *should* always be encrypted - unless perhaps the unencrypted private key is obtained and itself stored in some sort of secure place.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkPublicKey.pb"
IncludeFile "CkPrivateKey.pb"
IncludeFile "CkRsa.pb"

Procedure ChilkatExample()

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

    rsa.i = CkRsa::ckCreate()
    If rsa.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Generate a 2048-bit key.  Chilkat RSA supports
    ; key sizes ranging from 512 bits to 8192 bits.
    success.i = CkRsa::ckGenerateKey(rsa,2048)
    If success <> 1
        Debug CkRsa::ckLastErrorText(rsa)
        CkRsa::ckDispose(rsa)
        ProcedureReturn
    EndIf

    ; Get the public and private key parts:
    pubKey.i = CkRsa::ckExportPublicKeyObj(rsa)
    privKey.i = CkRsa::ckExportPrivateKeyObj(rsa)

    ; Get the public key as a PKCS8 PEM string
    pubKeyPem.s = CkPublicKey::ckGetPem(pubKey,0)
    Debug pubKeyPem

    ; Get the public key in PKCS8 format, in a Base64 encoded string.
    pubKeyPkcs8Base64.s = CkPublicKey::ckGetEncoded(pubKey,0,"base64")
    Debug pubKeyPkcs8Base64

    ; Get the public key in PKCS1 format, in a Base64 encoded string.
    pubKeyPkcs1Base64.s = CkPublicKey::ckGetEncoded(pubKey,1,"base64")
    Debug pubKeyPkcs1Base64

    ; Get the private key in a PKCS8 PEM string.
    privKeyPem.s = CkPrivateKey::ckGetPkcs8Pem(privKey)
    Debug privKeyPem

    ; Get the private key in a PKCS8 encrypted PEM string.
    privKeyEncPem.s = CkPrivateKey::ckGetPkcs8EncryptedPem(privKey,"myPassword")
    Debug privKeyEncPem

    ; Get the private key in PKCS1 Base64 format
    privKeyPkcs1Base64.s = CkPrivateKey::ckGetPkcs1ENC(privKey,"base64")
    Debug privKeyPkcs1Base64

    ; Get the private key in PKCS8 Base64 format
    privKeyPkcs8Base64.s = CkPrivateKey::ckGetPkcs8ENC(privKey,"base64")
    Debug privKeyPkcs8Base64

    ; Save to PKCS1 / PKCS8 / PEM files...

    ; Save the public key to PKCS8 binary DER
    success = CkPublicKey::ckSaveDerFile(pubKey,0,"pubKey_pkcs8.der")

    ; Save the public key to PKCS1 binary DER
    success = CkPublicKey::ckSaveDerFile(pubKey,"pubKey_pkcs1.der")

    ; Save the private key to unencrypted binary PKCS1 DER.
    ; Note: PKCS1 is never found in an encrypted format. 
    success = CkPrivateKey::ckSavePkcs1File(privKey,"privKey_pkcs1.der")

    ; Save the private key to unencrypted binary PKCS8
    success = CkPrivateKey::ckSavePkcs8File(privKey,"privKey_pkcs8.der")

    ; Save the private key to encrypted binary PKCS8
    success = CkPrivateKey::ckSavePkcs8EncryptedFile(privKey,"myPassword","privKey_enc_pkcs8.der")

    ; Save the private key to unencrypted PKCS8 PEM
    success = CkPrivateKey::ckSavePkcs8PemFile(privKey,"privKey.pem")

    ; Save the private key to encrypted PKCS8 PEM
    success = CkPrivateKey::ckSavePkcs8EncryptedPemFile(privKey,"myPassword","privKey_enc.pem")

    CkPublicKey::ckDispose(pubKey)

    CkPrivateKey::ckDispose(privKey)



    CkRsa::ckDispose(rsa)


    ProcedureReturn
EndProcedure