lib/multihashes.rb in multihashes-0.1.3 vs lib/multihashes.rb in multihashes-0.2.0

@@ -1,30 +1,25 @@
 require 'multihashes/version'
+require 'multicodecs'
 
 module Multihashes
   class HashFunctionNotImplemented < StandardError; end
   class DigestLengthError < StandardError; end
 
-  # https://github.com/jbenet/multihash
-  TABLE = {
-    0xd5 => 'md5',
-    0x11 => 'sha1',
-    0x12 => 'sha2-256',
-    0x13 => 'sha2-512',
-    0x14 => 'sha3',
-    0x40 => 'blake2b',
-    0x41 => 'blake2s'
-  }
+  # https://github.com/multiformats/multicodec/blob/master/table.csv
+  TABLE = Multicodecs.where(tag: 'multihash')
+    .map { |codec| [codec.code, codec.name] }
+    .to_h
 
   def self.encode(digest, hash_function)
     length = digest.bytesize
     key = TABLE.key hash_function
     raise HashFunctionNotImplemented, 'unknown hash function code' if key.nil?
-    [TABLE.key(hash_function), length, digest].pack("CCA#{length}")
+    [TABLE.key(hash_function), length, digest].pack("CCa#{length}")
   end
 
   def self.decode(multihash)
-    integer, length, digest = multihash.unpack('CCA*')
+    integer, length, digest = multihash.unpack('CCa*')
 
     if length != digest.bytesize
       raise DigestLengthError, 'digest did not match expected multihash length'
     end