Unicode C
Unicode C
SharePoint -- Get Server Form Digest Value
Demonstrates how to get a server form digest value to be placed in the X-RequestDigest HTTP request header for POST, PUT, MERGE, and DELETE requests. A form digest value is typically valid for 1800 seconds (i.e. 30 minutes). This example persists the value to a file, and only requests a new form digest value if the existing one is near expiration.Chilkat Unicode C Downloads
#include <C_CkFileAccessW.h>
#include <C_CkXmlW.h>
#include <C_CkDateTimeW.h>
#include <C_CkHttpW.h>
#include <C_CkHttpResponseW.h>
void ChilkatSample(void)
{
BOOL success;
HCkFileAccessW fac;
HCkXmlW xml;
HCkDateTimeW dtExpire;
HCkDateTimeW dtNow;
const wchar_t *formDigestXmlFile;
int tNow;
int tExpire;
HCkHttpW http;
const wchar_t *savedAccept;
HCkHttpResponseW resp;
HCkXmlW xml2;
int timeoutInSec;
success = FALSE;
// This requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// First, let's see if we already have a persisted form digest value
// that hasn't yet expired.
fac = CkFileAccessW_Create();
xml = CkXmlW_Create();
// My example code (below) persists the form digest XML in this format:
//
// <savedFormDigestValue>
// <d:ExpireDateTime>2017-04-12T20:46:39Z</d:ExpireDateTime>
// <d:FormDigestValue>0x3059FFB920651834540F3E6792EA73F5746B302E953FF4E808E485DB1E6C2836C7CF924644995F092453B02A94DE14A7962674B7B16780AF16EAFB8C246BCDC7,12 Apr 2017 17:08:22 -0000</d:FormDigestValue>
// </savedFormDigestValue>
//
dtExpire = CkDateTimeW_Create();
dtNow = CkDateTimeW_Create();
formDigestXmlFile = L"qa_data/sharepoint/savedFormDigestValue.xml";
if (CkFileAccessW_FileExists(fac,formDigestXmlFile) == TRUE) {
CkXmlW_LoadXmlFile(xml,formDigestXmlFile);
// Get the expire date/time
CkDateTimeW_SetFromTimestamp(dtExpire,CkXmlW_getChildContent(xml,L"d:ExpireDateTime"));
// Get the current date/time
CkDateTimeW_SetFromCurrentSystemTime(dtNow);
// Get both times as Unix time values
tNow = CkDateTimeW_GetAsUnixTime(dtNow,FALSE);
tExpire = CkDateTimeW_GetAsUnixTime(dtExpire,FALSE);
// If tNow >= tExpire, then fall through.
// Otherwise, just use the cached digest value.
if (tNow < tExpire) {
wprintf(L"Cached digest value is not yet expired.\n");
wprintf(L"X-RequestDigest: %s\n",CkXmlW_getChildContent(xml,L"d:FormDigestValue"));
CkFileAccessW_Dispose(fac);
CkXmlW_Dispose(xml);
CkDateTimeW_Dispose(dtExpire);
CkDateTimeW_Dispose(dtNow);
return;
}
}
// If we got to this point, the cached digest value either does not exist, or expired.
http = CkHttpW_Create();
// If SharePoint Windows classic authentication is used, then set the
// Login, Password, LoginDomain, and NtlmAuth properties.
CkHttpW_putLogin(http,L"SHAREPOINT_USERNAME");
CkHttpW_putPassword(http,L"SHAREPOINT_PASSWORD");
CkHttpW_putLoginDomain(http,L"SHAREPOINT_NTLM_DOMAIN");
CkHttpW_putNtlmAuth(http,TRUE);
// The more common case is to use SharePoint Online authentication (via the SPOIDCRL cookie).
// If so, do not set Login, Password, LoginDomain, and NtlmAuth, and instead
// establish the cookie as shown at SharePoint Online Authentication
// When creating, updating, and deleting SharePoint entities, we'll need
// to first get the server's form digest value to send in the X-RequestDigest header.
// This can be retrieved by making a POST request with an empty body to
// http://<site url>/_api/contextinfo and extracting the value of the
// d:FormDigestValue node in the XML that the contextinfo endpoint returns.
// Apparently, SharePoint needs an "Accept" request header equal to "application/xml",
// otherwise SharePoint will return an utterly incomprehensible and useless error message.
savedAccept = CkHttpW_ck_accept(http);
CkHttpW_putAccept(http,L"application/xml");
// Note: The last argument ("utf-8") is meaningless here because the body is empty.
resp = CkHttpResponseW_Create();
success = CkHttpW_HttpStr(http,L"POST",L"https://SHAREPOINT_HTTPS_DOMAIN/_api/contextinfo",L"",L"utf-8",L"application/xml",resp);
if (success == FALSE) {
wprintf(L"%s\n",CkHttpW_lastErrorText(http));
CkFileAccessW_Dispose(fac);
CkXmlW_Dispose(xml);
CkDateTimeW_Dispose(dtExpire);
CkDateTimeW_Dispose(dtNow);
CkHttpW_Dispose(http);
CkHttpResponseW_Dispose(resp);
return;
}
// Restore the default Accept header
CkHttpW_putAccept(http,savedAccept);
if (CkHttpResponseW_getStatusCode(resp) != 200) {
// A response status code not equal to 200 indicates failure.
wprintf(L"Response status code = %d\n",CkHttpResponseW_getStatusCode(resp));
wprintf(L"Response body:\n");
wprintf(L"%s\n",CkHttpResponseW_bodyStr(resp));
CkFileAccessW_Dispose(fac);
CkXmlW_Dispose(xml);
CkDateTimeW_Dispose(dtExpire);
CkDateTimeW_Dispose(dtNow);
CkHttpW_Dispose(http);
CkHttpResponseW_Dispose(resp);
return;
}
CkXmlW_LoadXml(xml,CkHttpResponseW_bodyStr(resp));
// The response XML looks like this:
// <?xml version="1.0" encoding="utf-8" ?>
// <d:GetContextWebInformation xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns:georss="http://www.georss.org/georss" xmlns:gml="http://www.opengis.net/gml" m:type="SP.ContextWebInformation">
// <d:FormDigestTimeoutSeconds m:type="Edm.Int32">1800</d:FormDigestTimeoutSeconds>
// <d:FormDigestValue>0x3059FFB920651834540F3E6792EA73F5746B302E953FF4E808E485DB1E6C2836C7CF924644995F092453B02A94DE14A7962674B7B16780AF16EAFB8C246BCDC7,12 Apr 2017 17:08:22 -0000</d:FormDigestValue>
// <d:LibraryVersion>15.0.4569.1000</d:LibraryVersion>
// <d:SiteFullUrl>https://SHAREPOINT_HTTPS_DOMAIN</d:SiteFullUrl>
// <d:SupportedSchemaVersions m:type="Collection(Edm.String)">
// <d:element>14.0.0.0</d:element>
// <d:element>15.0.0.0</d:element>
// </d:SupportedSchemaVersions>
// <d:WebFullUrl>https://SHAREPOINT_HTTPS_DOMAIN</d:WebFullUrl>
// </d:GetContextWebInformation>
//
// Cache the digest value, and also an expiration time. If this code is run again
// before the digest expires, we'll just get it from the file.
xml2 = CkXmlW_Create();
CkXmlW_putTag(xml2,L"savedFormDigestValue");
CkXmlW_NewChild2(xml2,L"d:FormDigestValue",CkXmlW_getChildContent(xml,L"d:FormDigestValue"));
timeoutInSec = CkXmlW_GetChildIntValue(xml,L"d:FormDigestTimeoutSeconds");
wprintf(L"Timeout in seconds = %d\n",timeoutInSec);
// Convert this to an expire timestamp.
// Let's make it expire 30 seconds prior to the actual timeout, just to be safe.
if (timeoutInSec > 30) {
timeoutInSec = timeoutInSec - 30;
}
CkDateTimeW_SetFromCurrentSystemTime(dtExpire);
CkDateTimeW_AddSeconds(dtExpire,timeoutInSec);
CkXmlW_NewChild2(xml2,L"d:ExpireDateTime",CkDateTimeW_getAsTimestamp(dtExpire,FALSE));
// Persist the digest and expire time to a file.
CkXmlW_SaveXml(xml2,formDigestXmlFile);
wprintf(L"Here is the new form digest value:\n");
wprintf(L"X-RequestDigest: %s\n",CkXmlW_getChildContent(xml,L"d:FormDigestValue"));
CkFileAccessW_Dispose(fac);
CkXmlW_Dispose(xml);
CkDateTimeW_Dispose(dtExpire);
CkDateTimeW_Dispose(dtNow);
CkHttpW_Dispose(http);
CkHttpResponseW_Dispose(resp);
CkXmlW_Dispose(xml2);
}