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Unicode C

Extract TSTInfo from RFC3161 Timestamp Reply

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Sends an RFC 3161 timestamp request to a TSA (Timestamp Authority) server and converts the timestamp reply to XML, and then extracts the TSTInfo from the XML and converts it to XML.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkCrypt2W.h>
#include <C_CkHttpW.h>
#include <C_CkBinDataW.h>
#include <C_CkHttpResponseW.h>
#include <C_CkAsnW.h>
#include <C_CkXmlW.h>
#include <C_CkStringBuilderW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCrypt2W crypt;
    const wchar_t *base64Hash;
    HCkHttpW http;
    HCkBinDataW requestToken;
    const wchar_t *optionalPolicyOid;
    BOOL addNonce;
    BOOL requestTsaCert;
    const wchar_t *tsaUrl;
    HCkHttpResponseW resp;
    HCkBinDataW timestampReply;
    HCkAsnW asn;
    HCkXmlW xml;
    const wchar_t *tstInfoBase64;
    HCkBinDataW bdTstInfo;
    HCkAsnW asnTstInfo;
    HCkXmlW xmlTstInfo;
    HCkStringBuilderW sbGenTime;

    success = FALSE;

    // Note: Requires Chilkat v9.5.0.75 or greater.

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

    // First sha-256 hash the data that is to be timestamped.
    // In this example, the data is the string "Hello World"

    crypt = CkCrypt2W_Create();
    CkCrypt2W_putHashAlgorithm(crypt,L"sha256");
    CkCrypt2W_putEncodingMode(crypt,L"base64");
    base64Hash = CkCrypt2W_hashFileENC(crypt,L"qa_data/hamlet.xml");

    http = CkHttpW_Create();

    requestToken = CkBinDataW_Create();
    optionalPolicyOid = L"";
    addNonce = FALSE;
    requestTsaCert = TRUE;

    // Create a time-stamp request token
    success = CkHttpW_CreateTimestampRequest(http,L"sha256",base64Hash,optionalPolicyOid,addNonce,requestTsaCert,requestToken);
    if (success == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkCrypt2W_Dispose(crypt);
        CkHttpW_Dispose(http);
        CkBinDataW_Dispose(requestToken);
        return;
    }

    // Send the time-stamp request token to the TSA.
    // This is the equivalent of the following CURL command:
    // curl -H "Content-Type: application/timestamp-query" --data-binary '@file.tsq' http://timestamp.digicert.com > file.tsr
    tsaUrl = L"http://timestamp.digicert.com";
    resp = CkHttpResponseW_Create();
    success = CkHttpW_HttpBd(http,L"POST",tsaUrl,requestToken,L"application/timestamp-query",resp);
    if (success == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkCrypt2W_Dispose(crypt);
        CkHttpW_Dispose(http);
        CkBinDataW_Dispose(requestToken);
        CkHttpResponseW_Dispose(resp);
        return;
    }

    // Get the timestamp reply from the HTTP response object.
    timestampReply = CkBinDataW_Create();
    CkHttpResponseW_GetBodyBd(resp,timestampReply);

    // Convert the binary timestamp reply to XML
    asn = CkAsnW_Create();
    success = CkAsnW_LoadBd(asn,timestampReply);
    if (success == FALSE) {
        wprintf(L"%s\n",CkAsnW_lastErrorText(asn));
        CkCrypt2W_Dispose(crypt);
        CkHttpW_Dispose(http);
        CkBinDataW_Dispose(requestToken);
        CkHttpResponseW_Dispose(resp);
        CkBinDataW_Dispose(timestampReply);
        CkAsnW_Dispose(asn);
        return;
    }

    xml = CkXmlW_Create();
    success = CkXmlW_LoadXml(xml,CkAsnW_asnToXml(asn));

    // Extract the TSTInfo from the XML.
    // The TSTInfo is this base64 encoded ASN.1 

    // TSTInfo ::= SEQUENCE  {
    //    version                      INTEGER  { v1(1) },
    //    policy                       TSAPolicyId,
    //    messageImprint               MessageImprint,
    //      -- MUST have the same value as the similar field in
    //      -- TimeStampReq
    //    serialNumber                 INTEGER,
    //     -- Time-Stamping users MUST be ready to accommodate integers
    //     -- up to 160 bits.
    //    genTime                      GeneralizedTime,
    //    accuracy                     Accuracy                 OPTIONAL,
    //    ordering                     BOOLEAN             DEFAULT FALSE,
    //    nonce                        INTEGER                  OPTIONAL,
    //      -- MUST be present if the similar field was present
    //      -- in TimeStampReq.  In that case it MUST have the same value.
    //    tsa                          [0] GeneralName          OPTIONAL,
    //    extensions                   [1] IMPLICIT Extensions   OPTIONAL  }

    tstInfoBase64 = CkXmlW_getChildContent(xml,L"sequence[1]|contextSpecific|sequence|sequence|contextSpecific|octets");

    bdTstInfo = CkBinDataW_Create();
    CkBinDataW_AppendEncoded(bdTstInfo,tstInfoBase64,L"base64");

    asnTstInfo = CkAsnW_Create();
    success = CkAsnW_LoadBd(asnTstInfo,bdTstInfo);
    if (success == FALSE) {
        wprintf(L"%s\n",CkAsnW_lastErrorText(asnTstInfo));
        CkCrypt2W_Dispose(crypt);
        CkHttpW_Dispose(http);
        CkBinDataW_Dispose(requestToken);
        CkHttpResponseW_Dispose(resp);
        CkBinDataW_Dispose(timestampReply);
        CkAsnW_Dispose(asn);
        CkXmlW_Dispose(xml);
        CkBinDataW_Dispose(bdTstInfo);
        CkAsnW_Dispose(asnTstInfo);
        return;
    }

    xmlTstInfo = CkXmlW_Create();
    success = CkXmlW_LoadXml(xmlTstInfo,CkAsnW_asnToXml(asnTstInfo));
    wprintf(L"%s\n",CkXmlW_getXml(xmlTstInfo));

    // Here's the TSTInfo XML:

    // <?xml version="1.0" encoding="utf-8"?>
    // <sequence>
    //     <int>01</int>
    //     <oid>2.16.840.1.114412.7.1</oid>
    //     <sequence>
    //         <sequence>
    //             <oid>2.16.840.1.101.3.4.2.1</oid>
    //             <null/>
    //         </sequence>
    //         <octets>4sRRyWOzC7EOic4fQ9+Op1pa10DbgoBGjBvkq09LZmE=</octets>
    //     </sequence>
    //     <int>00AD2C86E49872597B60F87D5C54BCFFAE</int>
    //     <universal tag="24" constructed="0">MjAyMzAzMTYxMTQ5NTJa</universal>
    // </sequence>

    //    The genTime (GeneralizedTime) is contained in the final "universal" XML element and is 
    //    in base64. It is the time at which the time-stamp token has been created by
    //    the TSA. After decoding from base64, it is:
    // 
    //    The syntax is: YYYYMMDDhhmmss[.s...]Z
    //    Example: 19990609001326.34352Z

    sbGenTime = CkStringBuilderW_Create();
    CkStringBuilderW_DecodeAndAppend(sbGenTime,CkXmlW_getChildContent(xmlTstInfo,L"universal"),L"base64",L"utf-8");
    wprintf(L"%s\n",CkStringBuilderW_getAsString(sbGenTime));

    // Result:
    // 20230316115718Z


    CkCrypt2W_Dispose(crypt);
    CkHttpW_Dispose(http);
    CkBinDataW_Dispose(requestToken);
    CkHttpResponseW_Dispose(resp);
    CkBinDataW_Dispose(timestampReply);
    CkAsnW_Dispose(asn);
    CkXmlW_Dispose(xml);
    CkBinDataW_Dispose(bdTstInfo);
    CkAsnW_Dispose(asnTstInfo);
    CkXmlW_Dispose(xmlTstInfo);
    CkStringBuilderW_Dispose(sbGenTime);

    }