commit 1cca38f3de0cb819fb926aab73b78ad94f835b33
Author: khoicodesthings <khoitrinh@ou.edu>
Date:   Tue Jan 25 12:06:04 2022 -0600

    Cloned from Dr. Maiti

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..a3cf278
--- /dev/null
+++ b/README.md
@@ -0,0 +1,2 @@
+# CS5970S22
+
diff --git a/hashing-examples.go b/hashing-examples.go
new file mode 100644
index 0000000..df180ff
--- /dev/null
+++ b/hashing-examples.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"crypto/md5"
+	"crypto/sha256"
+	"fmt"
+)
+
+func main() {
+	s := "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"
+
+	sha256 := sha256.Sum256([]byte(s))
+	md5 := md5.Sum([]byte(s))
+
+	fmt.Println()
+	fmt.Println(s)
+
+	fmt.Println()
+	fmt.Printf("%x", sha256)
+	fmt.Println()
+
+	fmt.Println()
+	fmt.Printf("%x", md5)
+
+	fmt.Println()
+	fmt.Println()
+
+}
diff --git a/hello.go b/hello.go
new file mode 100644
index 0000000..cb79ce4
--- /dev/null
+++ b/hello.go
@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("hello world")
+
+	sum := 0
+	for i := 0; i < 10; i++ {
+		fmt.Println(sum)
+		sum += i
+	}
+
+	fmt.Println(sum)
+}
diff --git a/rsa-encrypt-sign.go b/rsa-encrypt-sign.go
new file mode 100644
index 0000000..0874ef7
--- /dev/null
+++ b/rsa-encrypt-sign.go
@@ -0,0 +1,127 @@
+// Derived from: https://medium.com/@bobgzm/golang-cryptography-rsa-asymmetric-algorithm-e91363a2f7b3
+
+package main
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha256"
+	"fmt"
+	"os"
+)
+
+func main() {
+
+	alicePrivateKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	alicePublicKey := &alicePrivateKey.PublicKey
+
+	bobPrivateKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	bobPublicKey := &bobPrivateKey.PublicKey
+
+	fmt.Println("Alice's Private Key : ", alicePrivateKey)
+	fmt.Println()
+	fmt.Println("Alice's Public key ", alicePublicKey)
+	fmt.Println()
+	fmt.Println("Bob's Private Key : ", bobPrivateKey)
+	fmt.Println()
+	fmt.Println("Bob's Public key ", bobPublicKey)
+	fmt.Println()
+
+	message := []byte("first rule of cs5970 is that you tell everyone about cs5970")
+	label := []byte("")
+	hash := sha256.New()
+
+	ciphertext, err := rsa.EncryptOAEP(
+		hash,
+		rand.Reader,
+		bobPublicKey,
+		message,
+		label)
+
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// OAEP is a padding scheme, used with RSA
+	fmt.Printf("OAEP encrypted [%s] to \n[%x]\n", string(message), ciphertext)
+	fmt.Println()
+
+	ciphertext2, err := rsa.EncryptOAEP(
+		hash,
+		rand.Reader,
+		bobPublicKey,
+		message,
+		label)
+
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// OAEP is a padding scheme, used with RSA
+	fmt.Printf("OAEP encrypted [%s] to \n[%x]\n", string(message), ciphertext2)
+	fmt.Println()
+
+	var opts rsa.PSSOptions
+	opts.SaltLength = rsa.PSSSaltLengthAuto // for simple example
+	PSSmessage := message
+	newhash := crypto.SHA256
+	pssh := newhash.New()
+	pssh.Write(PSSmessage)
+
+	hashed := pssh.Sum(nil)
+	signature, err := rsa.SignPSS(
+		rand.Reader,
+		alicePrivateKey,
+		newhash,
+		hashed,
+		&opts)
+
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// Probabilistic Signature Scheme (PSS)
+	fmt.Printf("PSS Signature : %x\n", signature)
+	fmt.Println()
+
+	plainText, err := rsa.DecryptOAEP(
+		hash,
+		rand.Reader,
+		bobPrivateKey,
+		ciphertext,
+		label)
+
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	fmt.Printf("OAEP decrypted [%x] to \n[%s]\n", ciphertext, plainText)
+	fmt.Println()
+
+	err = rsa.VerifyPSS(
+		alicePublicKey,
+		newhash,
+		hashed,
+		signature,
+		&opts)
+
+	if err != nil {
+		fmt.Println("Signature verification failed!")
+		os.Exit(1)
+	} else {
+		fmt.Println("Verify Signature successful!")
+	}
+}