From 0bfb77c9af9ec0ad60d66d7680c1a05239a9dd2f Mon Sep 17 00:00:00 2001
From: Balasankar 'Balu' C <balu@dravidam.net>
Date: Tue, 30 May 2023 15:45:32 +0530
Subject: [PATCH] Support using CI_JOB_TOKEN for authentication

Signed-off-by: Balasankar 'Balu' C <balu@dravidam.net>
---
 lib/gitlab/configuration.rb |  3 ++-
 lib/gitlab/request.rb       | 15 ++++++++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/lib/gitlab/configuration.rb b/lib/gitlab/configuration.rb
index 8c3735429..bd7d7b45d 100644
--- a/lib/gitlab/configuration.rb
+++ b/lib/gitlab/configuration.rb
@@ -5,7 +5,7 @@ module Gitlab
   # Defines constants and methods related to configuration.
   module Configuration
     # An array of valid keys in the options hash when configuring a Gitlab::API.
-    VALID_OPTIONS_KEYS = %i[endpoint private_token user_agent sudo httparty].freeze
+    VALID_OPTIONS_KEYS = %i[endpoint private_token user_agent sudo httparty pat_prefix].freeze
 
     # The user agent that will be sent to the API endpoint if none is set.
     DEFAULT_USER_AGENT = "Gitlab Ruby Gem #{Gitlab::VERSION}"
@@ -37,6 +37,7 @@ def options
     def reset
       self.endpoint       = ENV['GITLAB_API_ENDPOINT'] || ENV['CI_API_V4_URL']
       self.private_token  = ENV['GITLAB_API_PRIVATE_TOKEN'] || ENV['GITLAB_API_AUTH_TOKEN']
+      self.pat_prefix     = nil
       self.httparty       = get_httparty_config(ENV['GITLAB_API_HTTPARTY_OPTIONS'])
       self.sudo           = nil
       self.user_agent     = DEFAULT_USER_AGENT
diff --git a/lib/gitlab/request.rb b/lib/gitlab/request.rb
index 218b81ba0..f1a01a30e 100644
--- a/lib/gitlab/request.rb
+++ b/lib/gitlab/request.rb
@@ -12,7 +12,7 @@ class Request
     headers 'Accept' => 'application/json', 'Content-Type' => 'application/x-www-form-urlencoded'
     parser(proc { |body, _| parse(body) })
 
-    attr_accessor :private_token, :endpoint
+    attr_accessor :private_token, :endpoint, :pat_prefix
 
     # Converts the response body to an ObjectifiedHash.
     def self.parse(body)
@@ -93,10 +93,19 @@ def request_defaults(sudo = nil)
     def authorization_header
       raise Error::MissingCredentials, 'Please provide a private_token or auth_token for user' unless private_token
 
-      if private_token.size < 21
+      # The Personal Access Token prefix can be at most 20 characters, and the
+      # generated part is of length 20 characters. Personal Access Tokens, thus
+      # can have a maximum size of 40 characters. GitLab uses
+      # `Doorkeeper::OAuth::Helpers::UniqueToken.generate` for generating
+      # OAuth2 tokens, and specified `hex` as token generator method. Thus, the
+      # OAuth2 tokens are of length more than 64. If the token length is below
+      # that, it is probably a Personal Access Token or CI_JOB_TOKEN.
+      if private_token.size >= 64
+        { 'Authorization' => "Bearer #{private_token}" }
+      elsif private_token.start_with?(pat_prefix.to_s)
         { 'PRIVATE-TOKEN' => private_token }
       else
-        { 'Authorization' => "Bearer #{private_token}" }
+        { 'JOB-TOKEN' => private_token }
       end
     end