Add schemes for estimating leaf certificate composition

benchmarks/benchmark.py

@@ -27,6 +27,8 @@ def load_schemes():
         schemes.existing.IntermediateSuppression(),
         schemes.existing.ICAAndTLS(),
         schemes.existing.HypotheticalOptimimum(),
+        schemes.existing.MetadataEstimate(),
+        schemes.existing.LeafDomainNames(),
         # This Draft
         schemes.abridged.PrefixOnly(),
         schemes.abridged.PrefixAndZstd(offlineCompression=False),

benchmarks/schemes/existing.py

@@ -119,3 +119,46 @@ def compress(self, cert_chain):
     def decompress(self, compressed_data):
         # Not defined.
         pass
+
+
+class MetadataEstimate:
+    def __init__(self):
+        pass
+
+    def name(self):
+        return "Leaf Certificate Metadata Estimate"
+
+    def footprint(self):
+        return 0
+
+    def compress(self, cert_chain):
+
+        (d, pk, s) = extract_subject_info(cert_chain[0])
+        compressed_domains = zstandard.compress(d, 22)
+        # Size Estimate := Certificate - pk - sig with compressed_domains and no SCTs.
+        size_estimate = len(cert_chain[0]) - len(d) - len(pk) - len(s) + len(compressed_domains)
+        size_estimate -= sum([len(x.signature) + len(x.log_id) for x in extract_scts(cert_chain[0])])
+        return b"x" * size_estimate
+
+    def decompress(self, compressed_data):
+        # Not defined.
+        pass
+
+class LeafDomainNames:
+    def __init__(self):
+        pass
+
+    def name(self):
+        return "Leaf Certificate Compressed Domains Estimate"
+
+    def footprint(self):
+        return 0
+
+    def compress(self, cert_chain):
+        (d, pk, s) = extract_subject_info(cert_chain[0])
+        compressed_domains = zstandard.compress(d, 22)
+        return compressed_domains
+
+    def decompress(self, compressed_data):
+        # Not defined.
+        pass