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Tcl

Refresh OAuth2 Access Token with Optional Params

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Demonstrates how to refresh an OAuth2 access token with optional query params included in the HTTP request.

Chilkat Tcl Downloads

Tcl

load ./chilkat.dll

set success 0

# Here is a sampling of possible optional parameters that might
# be used by some OAuth2 providers.

# Optional Parameters
# 
#     "scope":
#         Specifies the scope of the access request. If omitted, the authorization
#         server may issue a token with the same scope as the original token.
#         Example: "scope=read write"
# 
#     "redirect_uri":
#         The redirect URI used in the original authorization request. Some
#         servers may require this for validation.
#         Example: "redirect_uri=https://example.com/callback"
# 
#     "resource":
#         Indicates the target resource or audience for the token. This is used in
#         some implementations (e.g., Microsoft Identity Platform).
#         Example: "resource=https://api.example.com"
# 
#     "audience":
#         Similar to "resource", this specifies the intended audience for the
#         token (used in some OAuth2 implementations like Auth0).
#         Example: "audience=https://api.example.com"
# 
#     "client_assertion" and "client_assertion_type":
#         Used for client authentication using a signed JWT instead of a client
#         secret.
#         Example:client_assertion=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9...        
#         client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer
# 
#     "token_type_hint":
#         Provides a hint to the authorization server about the type of token
#         being refreshed. This is rarely used but can be helpful in some cases.
#         Example: "token_type_hint=refresh_token"
# 
#     "assertion":
#         Used in some flows (e.g., SAML bearer assertion flow) to provide an
#         assertion for token issuance.
#         Example: "assertion=PHNhbWxwOl..."
# 
#     "requested_token_use":
#         Specifies how the token will be used (e.g., "on_behalf_of" in the
#         On-Behalf-Of flow used by Microsoft Identity Platform).
#         Example: "requested_token_use=on_behalf_of"
# 

# --------------------------------------------------------------------------------
# This example wll refresh the access token and includes the "audience"
# optional query parameter.
# 
# 

# Get the access token to be refreshed.
set jsonToken [new_CkJsonObject]

set success [CkJsonObject_LoadFile $jsonToken "qa_data/tokens/myAccessToken.json"]
if {$success != 1} then {
    puts "Failed to load hmrc.json"
    delete_CkJsonObject $jsonToken
    exit
}

set oauth2 [new_CkOAuth2]

CkOAuth2_put_TokenEndpoint $oauth2 "https://api.example.com/oauth/token"

# Replace these with actual values.
CkOAuth2_put_ClientId $oauth2 "CLIENT_ID"
CkOAuth2_put_ClientSecret $oauth2 "CLIENT_SECRET"

# Add the optional refresh query param.
# Call AddRefreshQueryParam multiple times to add additional params.
CkOAuth2_AddRefreshQueryParam $oauth2 "audience" "https://api.example.com"

# Provide the existing refresh token from the JSON.
CkOAuth2_put_RefreshToken $oauth2 [CkJsonObject_stringOf $jsonToken "refresh_token"]

# Send the HTTP POST to refresh the access token..
set success [CkOAuth2_RefreshAccessToken $oauth2]
if {$success != 1} then {
    puts [CkOAuth2_lastErrorText $oauth2]
    delete_CkJsonObject $jsonToken
    delete_CkOAuth2 $oauth2
    exit
}

# Load the access token response into the json object 
CkJsonObject_Load $jsonToken [CkOAuth2_accessTokenResponse $oauth2]

# Save the new JSON access token response to a file.
# The access + refresh tokens contained in this JSON will be needed for the next refresh.
set sbJson [new_CkStringBuilder]

CkJsonObject_put_EmitCompact $jsonToken 0
CkJsonObject_EmitSb $jsonToken $sbJson
CkStringBuilder_WriteFile $sbJson "qa_data/tokens/myAccessToken.json" "utf-8" 0

puts "OAuth2 access token refreshed!"
puts "New Access Token = [CkOAuth2_accessToken $oauth2]"

delete_CkJsonObject $jsonToken
delete_CkOAuth2 $oauth2
delete_CkStringBuilder $sbJson