From 27a109af019e94595c68568f85dd635eb260fd69 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Thu, 31 Mar 2016 16:15:07 -0600
Subject: [PATCH] Improve testing and API of CSHA256 compression.

---
 src/crypto/sha256.h               | 15 +++++++++------
 src/test/sha256compress_tests.cpp | 22 ++++++++++++++++++++++
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/src/crypto/sha256.h b/src/crypto/sha256.h
index 1c449b834..8ecb7348d 100644
--- a/src/crypto/sha256.h
+++ b/src/crypto/sha256.h
@@ -11,19 +11,22 @@
 /** A hasher class for SHA-256. */
 class CSHA256
 {
-private:
-    uint32_t s[8];
-    unsigned char buf[64];
-    size_t bytes;
-
 public:
     static const size_t OUTPUT_SIZE = 32;
 
     CSHA256();
     CSHA256& Write(const unsigned char* data, size_t len);
     void Finalize(unsigned char hash[OUTPUT_SIZE]);
-    void FinalizeNoPadding(unsigned char hash[OUTPUT_SIZE], bool enforce_compression = true);
+    void FinalizeNoPadding(unsigned char hash[OUTPUT_SIZE]) {
+    	FinalizeNoPadding(hash, true);
+    };
     CSHA256& Reset();
+
+private:
+    uint32_t s[8];
+    unsigned char buf[64];
+    size_t bytes;
+    void FinalizeNoPadding(unsigned char hash[OUTPUT_SIZE], bool enforce_compression);
 };
 
 #endif // BITCOIN_CRYPTO_SHA256_H
diff --git a/src/test/sha256compress_tests.cpp b/src/test/sha256compress_tests.cpp
index aec36f073..f0b7ed435 100644
--- a/src/test/sha256compress_tests.cpp
+++ b/src/test/sha256compress_tests.cpp
@@ -30,6 +30,28 @@ BOOST_AUTO_TEST_CASE(compression)
 		uint256 digest;
 		BOOST_CHECK_THROW(hasher.FinalizeNoPadding(digest.begin()), std::length_error);
 	}
+
+	{
+		unsigned char preimage[65] = {};
+		CSHA256 hasher;
+		hasher.Write(&preimage[0], 65);
+		uint256 digest;
+		BOOST_CHECK_THROW(hasher.FinalizeNoPadding(digest.begin()), std::length_error);
+	}
+
+	{
+		unsigned char n = 0x00;
+		CSHA256 hasher;
+		for (size_t i = 0; i < 64; i++) {
+			hasher.Write(&n, 1);
+		}
+		uint256 digest;
+
+		hasher.FinalizeNoPadding(digest.begin());
+
+		BOOST_CHECK_MESSAGE(digest == uint256S("d8a93718eaf9feba4362d2c091d4e58ccabe9f779957336269b4b917be9856da"),
+			                digest.GetHex());
+	}
 }
 
 BOOST_AUTO_TEST_SUITE_END()