add PKCS1.5 and Legacy algorithms to fizz::toString

Summary: Fizz does not support these algorithms, but since Fizz is often used to read the initial TLS ClientHello, which may be from an older version of TLS, it is helpful to be able to print these values.

Reviewed By: mingtaoy

Differential Revision: D66736193

fbshipit-source-id: 8b3b5403d0fa09c873e59aac463e4f171b14e17a

fizz/record/Types.cpp

@@ -236,6 +236,25 @@ std::string toString(SignatureScheme sigScheme) {
     case SignatureScheme::rsa_pss_sha256_batch:
       return "rsa_pss_sha256_batch";
   }
+  // Handle legacy/compatibility algorithms
+  uint16_t val = static_cast<uint16_t>(sigScheme);
+  switch (val) {
+    // RSASSA-PKCS1-v1_5 algorithms
+    case 0x0401:
+      return "rsa_pkcs1_sha256";
+    case 0x0501:
+      return "rsa_pkcs1_sha384";
+    case 0x0601:
+      return "rsa_pkcs1_sha512";
+    // Fizz does not support these algorithms. They are listed
+    // here solely to aid in debugging when printing non-TLS 1.3
+    // ClientHellos (for example, in the fizzHandshakeFallback
+    // path)
+    case 0x0201:
+      return "rsa_pkcs1_sha1";
+    case 0x0203:
+      return "ecdsa_sha1";
+  }
   return enumToHex(sigScheme);
 }