refactor(model): Teach hash algorithms about their value string size

This allows to simply code a bit and to implement consistency checks for
string lengths.

Signed-off-by: Sebastian Schuberth <[email protected]>

model/src/main/kotlin/HashAlgorithm.kt

@@ -20,6 +20,7 @@
 package org.ossreviewtoolkit.model
 
 import com.fasterxml.jackson.annotation.JsonCreator
+import com.fasterxml.jackson.annotation.JsonIgnore
 import com.fasterxml.jackson.annotation.JsonValue
 
 import java.io.File
@@ -113,18 +114,15 @@ enum class HashAlgorithm(vararg val aliases: String, val emptyValue: String, val
          */
         fun create(value: String): HashAlgorithm {
             if (value.isBlank()) return NONE
-
-            return when (value.length) {
-                128 -> SHA512
-                96 -> SHA384
-                64 -> SHA256
-                40 -> SHA1
-                32 -> MD5
-                else -> UNKNOWN
-            }
+            return HashAlgorithm.entries.find { it.size == value.length } ?: UNKNOWN
         }
     }
 
+    /**
+     * The size of a hexadecimal hash value string for this algorithm.
+     */
+    val size = emptyValue.length
+
     /**
      * Convert the hash algorithm to a string representation.
      */