43 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Ruby
		
	
	
	
			
		
		
	
	
			43 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			Ruby
		
	
	
	
| # frozen_string_literal: true
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| 
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| module Gitlab
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|   module JwtAuthenticatable
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|     # Supposedly the effective key size for HMAC-SHA256 is 256 bits, i.e. 32
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|     # bytes https://tools.ietf.org/html/rfc4868#section-2.6
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|     SECRET_LENGTH = 32
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| 
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|     def self.included(base)
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|       base.extend(ClassMethods)
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|     end
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| 
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|     module ClassMethods
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|       include Gitlab::Utils::StrongMemoize
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| 
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|       def decode_jwt_for_issuer(issuer, encoded_message)
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|         JWT.decode(
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|           encoded_message,
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|           secret,
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|           true,
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|           { iss: issuer, verify_iss: true, algorithm: 'HS256' }
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|         )
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|       end
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| 
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|       def secret
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|         strong_memoize(:secret) do
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|           Base64.strict_decode64(File.read(secret_path).chomp).tap do |bytes|
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|             raise "#{secret_path} does not contain #{SECRET_LENGTH} bytes" if bytes.length != SECRET_LENGTH
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|           end
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|         end
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|       end
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| 
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|       def write_secret
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|         bytes = SecureRandom.random_bytes(SECRET_LENGTH)
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|         File.open(secret_path, 'w:BINARY', 0600) do |f|
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|           f.chmod(0600) # If the file already existed, the '0600' passed to 'open' above was a no-op.
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|           f.write(Base64.strict_encode64(bytes))
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|         end
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|       end
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|     end
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|   end
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| end
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