From 51381430456f790b9352d6d4a153b3a98bfa3635 Mon Sep 17 00:00:00 2001
From: Ethan Hsieh <ethan.hsieh@canonical.com>
Date: Sat, 14 Aug 2021 16:15:06 +0800
Subject: [PATCH] Add support for hash algorithm SM3 256

---
 types.go | 36 ++++++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/types.go b/types.go
index 0349a6c..30070e2 100644
--- a/types.go
+++ b/types.go
@@ -155,7 +155,20 @@ func (a HashAlgorithmId) GetHash() crypto.Hash {
 
 // Supported determines if the TPM digest algorithm has an equivalent go crypto.Hash.
 func (a HashAlgorithmId) Supported() bool {
-	return a.GetHash() != crypto.Hash(0)
+	switch a {
+	case HashAlgorithmSHA1:
+	case HashAlgorithmSHA256:
+	case HashAlgorithmSHA384:
+	case HashAlgorithmSHA512:
+	case HashAlgorithmSM3_256:
+	case HashAlgorithmSHA3_256:
+	case HashAlgorithmSHA3_384:
+	case HashAlgorithmSHA3_512:
+	default:
+		return false
+	}
+
+	return true
 }
 
 // Available determines if the TPM digest algorithm has an equivalent go crypto.Hash
@@ -172,7 +185,26 @@ func (a HashAlgorithmId) NewHash() hash.Hash {
 
 // Size returns the size of the algorithm. It will panic if HashAlgorithmId.Supported returns false.
 func (a HashAlgorithmId) Size() int {
-	return a.GetHash().Size()
+        switch a {
+        case HashAlgorithmSHA1:
+                return 20
+        case HashAlgorithmSHA256:
+                return 32
+        case HashAlgorithmSHA384:
+                return 48
+        case HashAlgorithmSHA512:
+                return 64
+        case HashAlgorithmSM3_256:
+                return 32
+        case HashAlgorithmSHA3_256:
+                return 32
+        case HashAlgorithmSHA3_384:
+                return 48
+        case HashAlgorithmSHA3_512:
+                return 64
+        default:
+                panic("unknown hash algorithm")
+        }
 }
 
 // SymAlgorithmId corresponds to the TPMI_ALG_SYM type
-- 
2.25.1