From 0c185d23a5fe3be278339fb9bf0bfa23c88da380 Mon Sep 17 00:00:00 2001
From: The-Tysonator <ring.oaks_0v@icloud.com>
Date: Wed, 11 Oct 2023 21:01:44 +0100
Subject: [PATCH] Added the SHA256 algorithm.

---
 README.md                      |  1 +
 algorithms/sha256/CheckHash.go | 21 +++++++++++++++++++++
 algorithms/sha256/Hash.go      | 20 ++++++++++++++++++++
 algorithms/sha256/algorithm.go | 10 ++++++++++
 4 files changed, 52 insertions(+)
 create mode 100644 algorithms/sha256/CheckHash.go
 create mode 100644 algorithms/sha256/Hash.go
 create mode 100644 algorithms/sha256/algorithm.go

diff --git a/README.md b/README.md
index 7bd9594..f3460bb 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@ GCL is a Go library designed to offer a robust collection of cryptographic algor
 GCL offers support for a diverse range of cryptographic algorithms, ensuring that your cryptographic requirements are comprehensively addressed. Our library includes:
 
 - [X] BLAKE2
+- [X] SHA256
 
 ## Installation
 
diff --git a/algorithms/sha256/CheckHash.go b/algorithms/sha256/CheckHash.go
new file mode 100644
index 0000000..5f3b23c
--- /dev/null
+++ b/algorithms/sha256/CheckHash.go
@@ -0,0 +1,21 @@
+package sha256
+
+import (
+	// Standard
+	"crypto/sha256"
+	"crypto/subtle"
+)
+
+// Check Hash
+func (Algorithm) CheckHash(data []byte, hashToCheck []byte) (bool, error) {
+	// Hasher
+	hasher := sha256.New()
+	// Write To Hasher
+	_, err := hasher.Write(data)
+	// Handle Error
+	if err != nil {
+		return false, err
+	}
+	// Return Hash
+	return subtle.ConstantTimeCompare(hasher.Sum(nil), hashToCheck) == 1, err
+}
diff --git a/algorithms/sha256/Hash.go b/algorithms/sha256/Hash.go
new file mode 100644
index 0000000..885acd0
--- /dev/null
+++ b/algorithms/sha256/Hash.go
@@ -0,0 +1,20 @@
+package sha256
+
+import (
+	// Standard
+	"crypto/sha256"
+)
+
+// Hash
+func (Algorithm) Hash(data []byte) ([]byte, error) {
+	// Hasher
+	hasher := sha256.New()
+	// Write To Hasher
+	_, err := hasher.Write(data)
+	// Handle Error
+	if err != nil {
+		return []byte(""), err
+	}
+	// Return Hash
+	return hasher.Sum(nil), err
+}
diff --git a/algorithms/sha256/algorithm.go b/algorithms/sha256/algorithm.go
new file mode 100644
index 0000000..f878f28
--- /dev/null
+++ b/algorithms/sha256/algorithm.go
@@ -0,0 +1,10 @@
+package sha256
+
+// Algorithm
+type Algorithm struct{}
+
+// New
+func New(size int) Algorithm {
+	// Return Algorithm
+	return Algorithm{}
+}