PureBasic
PureBasic
OAuth2 Token using IdentityServer4 with Client Credentials
See more OAuth2 Examples
Demonstrates how to get an OAuth2 access token using the client credential flow with IdentityServer4.Chilkat PureBasic Downloads
IncludeFile "CkHttpResponse.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkJsonArray.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkHttpRequest.pb"
Procedure ChilkatExample()
success.i = 0
; This example assumes the Chilkat API to have been previously unlocked.
; See Global Unlock Sample for sample code.
http.i = CkHttp::ckCreate()
If http.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
; The first step is to fetch your IdentityServer4's discovery document
; (OpenID Connect defines a discovery mechanism, called OpenID Connect Discovery, where an OpenID server publishes its metadata at a well-known URL,
; typically https://server.com/.well-known/openid-configuration
resp.i = CkHttpResponse::ckCreate()
If resp.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkHttp::ckHttpNoBody(http,"GET","https://localhost:5000/.well-known/openid-configuration",resp)
If success = 0
Debug CkHttp::ckLastErrorText(http)
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
ProcedureReturn
EndIf
If CkHttpResponse::ckStatusCode(resp) <> 200
Debug "Received response status code " + Str(CkHttpResponse::ckStatusCode(resp))
Debug "Response body containing error text or JSON:"
Debug CkHttpResponse::ckBodyStr(resp)
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
ProcedureReturn
EndIf
json.i = CkJsonObject::ckCreate()
If json.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkJsonObject::ckLoad(json,CkHttpResponse::ckBodyStr(resp))
; We have the discovery document, which contains something like this:
; You can use this online tool to generate parsing code from sample JSON:
; Generate Parsing Code from JSON
; {
; "issuer": "https://localhost:5000",
; "jwks_uri": "https://localhost:5000/.well-known/openid-configuration/jwks",
; "authorization_endpoint": "https://localhost:5000/connect/authorize",
; "token_endpoint": "https://localhost:5000/connect/token",
; "userinfo_endpoint": "https://localhost:5000/connect/userinfo",
; "end_session_endpoint": "https://localhost:5000/connect/endsession",
; "check_session_iframe": "https://localhost:5000/connect/checksession",
; "revocation_endpoint": "https://localhost:5000/connect/revocation",
; "introspection_endpoint": "https://localhost:5000/connect/introspect",
; "frontchannel_logout_supported": true,
; "frontchannel_logout_session_supported": true,
; "backchannel_logout_supported": true,
; "backchannel_logout_session_supported": true,
; "scopes_supported": [
; "openid",
; "profile",
; "email",
; "MyCompany.profile",
; "MyCompany.Identity.WebApi",
; "MyCompany.TriHub.WebApi",
; "offline_access"
; ],
; "claims_supported": [
; "sub",
; "updated_at",
; "locale",
; "zoneinfo",
; "birthdate",
; "gender",
; "website",
; "profile",
; "preferred_username",
; "nickname",
; "middle_name",
; "given_name",
; "family_name",
; "name",
; "picture",
; "email_verified",
; "email",
; "userId",
; "groups",
; "fullname"
; ],
; "grant_types_supported": [
; "authorization_code",
; "client_credentials",
; "refresh_token",
; "implicit",
; "password"
; ],
; "response_types_supported": [
; "code",
; "token",
; "id_token",
; "id_token token",
; "code id_token",
; "code token",
; "code id_token token"
; ],
; "response_modes_supported": [
; "form_post",
; "query",
; "fragment"
; ],
; "token_endpoint_auth_methods_supported": [
; "client_secret_basic",
; "client_secret_post"
; ],
; "subject_types_supported": [
; "public"
; ],
; "id_token_signing_alg_values_supported": [
; "RS256"
; ],
; "code_challenge_methods_supported": [
; "plain",
; "S256"
; ]
; }
;
; The next steps are to (1) get the token_endpoint,
; and (2) verify that the client_credentials grant type is supported.
tokenEndpoint.s = CkJsonObject::ckStringOf(json,"token_endpoint")
grantTypes.i = CkJsonObject::ckArrayOf(json,"grant_types_supported")
clientCredentialsIdx.i = CkJsonArray::ckFindString(grantTypes,"client_credentials",1)
CkJsonArray::ckDispose(grantTypes)
; If clientCredentialsIdx is less then zero (-1) then the "client_credentials" string was not found.
If clientCredentialsIdx < 0
Debug "The client credentials grant type is not supported."
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
CkJsonObject::ckDispose(json)
ProcedureReturn
EndIf
; Request the access token using our Client ID and Client Secret.
; We're going to duplicate this CURL statement:
; curl --request POST \
; --url '<tokenEndpoint>' \
; --header 'content-type: application/x-www-form-urlencoded' \
; --data 'grant_type=client_credentials&client_id=CLIENT_ID&client_secret=CLIENT_SECRET'
req.i = CkHttpRequest::ckCreate()
If req.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
CkHttpRequest::setCkHttpVerb(req, "POST")
CkHttpRequest::setCkContentType(req, "application/x-www-form-urlencoded")
CkHttpRequest::ckAddParam(req,"grant_type","client_credentials")
CkHttpRequest::ckAddParam(req,"client_id","CLIENT_ID")
CkHttpRequest::ckAddParam(req,"client_secret","CLIENT_SECRET") CkHttpRequest::setCkHttpVerb(req, "POST")
success = CkHttp::ckHttpReq(http,tokenEndpoint,req,resp)
If success = 0
Debug CkHttp::ckLastErrorText(http)
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
CkJsonObject::ckDispose(json)
CkHttpRequest::ckDispose(req)
ProcedureReturn
EndIf
; Make sure we got a 200 response status code, otherwise it's an error.
If CkHttpResponse::ckStatusCode(resp) <> 200
Debug "POST to token endpoint failed."
Debug "Received response status code " + Str(CkHttpResponse::ckStatusCode(resp))
Debug "Response body containing error text or JSON:"
Debug CkHttpResponse::ckBodyStr(resp)
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
CkJsonObject::ckDispose(json)
CkHttpRequest::ckDispose(req)
ProcedureReturn
EndIf
success = CkJsonObject::ckLoad(json,CkHttpResponse::ckBodyStr(resp))
; Our JSON response should contain this:
; {
; "access_token":"eyJz93a...k4laUWw",
; "token_type":"Bearer",
; "expires_in":86400
; }
; Get the access token:
accessToken.s = CkJsonObject::ckStringOf(json,"access_token")
; The access token is what gets added to "Authorization: Bearer <access_token>"
; for the subsequent REST API calls..
CkHttp::ckDispose(http)
CkHttpResponse::ckDispose(resp)
CkJsonObject::ckDispose(json)
CkHttpRequest::ckDispose(req)
ProcedureReturn
EndProcedure