(PureBasic) Sign String to create a CAdES-T Signature, using HTTP Proxy to Access Timestamp Server

This example will sign a string to create a CAdEST-T signature. It will use an HTTP proxy to access the timestamp server.

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IncludeFile "CkBinData.pb"
IncludeFile "CkCert.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkCrypt2.pb"

Procedure ChilkatExample()

    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

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

    CkCert::setCkSmartCardPin(cert, "123456")
    success.i = CkCert::ckLoadFromSmartcard(cert,"")
    If success <> 1
        Debug CkCert::ckLastErrorText(cert)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    success = CkCrypt2::ckSetSigningCert(crypt,cert)

    ; Use SHA-256 rather than the default of SHA-1
    CkCrypt2::setCkHashAlgorithm(crypt, "sha256")

    ; Create JSON that tells Chilkat what signing attributes to include:
    attrs.i = CkJsonObject::ckCreate()
    If attrs.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateBool(attrs,"contentType",1)
    CkJsonObject::ckUpdateBool(attrs,"signingTime",1)
    CkJsonObject::ckUpdateBool(attrs,"messageDigest",1)
    CkJsonObject::ckUpdateBool(attrs,"signingCertificateV2",1)

    ; A CAdES-T signature is one that includes a timestampToken created by an online TSA (time stamping authority).
    ; We must include the TSA's URL, as well as a few options to indicate what is desired.
    ; Except for the TSA URL, the options shown here are typically what you would need.
    CkJsonObject::ckUpdateBool(attrs,"timestampToken.enabled",1)
    CkJsonObject::ckUpdateString(attrs,"timestampToken.tsaUrl","https://freetsa.org/tsr")
    CkJsonObject::ckUpdateBool(attrs,"timestampToken.addNonce",0)
    CkJsonObject::ckUpdateBool(attrs,"timestampToken.requestTsaCert",1)
    CkJsonObject::ckUpdateString(attrs,"timestampToken.hashAlg","sha256")

    CkCrypt2::setCkSigningAttributes(crypt, CkJsonObject::ckEmit(attrs))

    strToSign.s = "Hello World!"

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

    CkBinData::ckAppendString(bd,strToSign,"utf-8")

    ; -------------------------------------------------------------------------
    ; The purpose of this example is to show how an HTTP object with custom
    ; settings can be used to access the Internet when signing.
    ; Access to the Internet is needed to communicate with the timestamp server.
    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; This can be a domain name, hostname, or IP address.
    CkHttp::setCkProxyDomain(http, "172.16.16.56")
    CkHttp::setCkProxyPort(http, 808)
    CkHttp::setCkProxyLogin(http, "myProxyLogin")
    CkHttp::setCkProxyPassword(http, "myProxyPassword")
    CkCrypt2::ckSetTsaHttpObj(crypt,http)
    ; -------------------------------------------------------------------------

    ; This creates the CAdES-T signature.  During the signature creation, it
    ; communicates with the TSA to get a timestampToken.
    ; The contents of bd are signed and replaced with the CAdES-T signature (which embeds the original content).
    success = CkCrypt2::ckOpaqueSignBd(crypt,bd)
    If success <> 1
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        CkJsonObject::ckDispose(attrs)
        CkBinData::ckDispose(bd)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf

    ; Get the signature in base64 format:
    Debug CkBinData::ckGetEncoded(bd,"base64_mime")

    Debug "Success."


    CkCrypt2::ckDispose(crypt)
    CkCert::ckDispose(cert)
    CkJsonObject::ckDispose(attrs)
    CkBinData::ckDispose(bd)
    CkHttp::ckDispose(http)


    ProcedureReturn
EndProcedure