├── README
└── rsa_sample.go


/README:
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1 | # Brainattica & Cryptography. Golang & Cryptography. RSA sample..
2 | 
3 | This repo make reference to a post in our blog [http://http://blog.brainattica.com/golang-cryptography-rsa/]


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/rsa_sample.go:
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 1 | package main
 2 | 
 3 | import (
 4 | 	"crypto"
 5 | 	"crypto/rand"
 6 | 	"crypto/rsa"
 7 | 	"crypto/sha256"
 8 | 	"fmt"
 9 | 	"os"
10 | )
11 | 
12 | func main() {
13 | 
14 | 	// Generate RSA Keys
15 | 	miryanPrivateKey, err := rsa.GenerateKey(rand.Reader, 2048)
16 | 
17 | 	if err != nil {
18 | 		fmt.Println(err.Error)
19 | 		os.Exit(1)
20 | 	}
21 | 
22 | 	miryanPublicKey := &miryanPrivateKey.PublicKey
23 | 
24 | 	raulPrivateKey, err := rsa.GenerateKey(rand.Reader, 2048)
25 | 
26 | 	if err != nil {
27 | 		fmt.Println(err.Error)
28 | 		os.Exit(1)
29 | 	}
30 | 
31 | 	raulPublicKey := &raulPrivateKey.PublicKey
32 | 
33 | 	fmt.Println("Private Key : ", miryanPrivateKey)
34 | 	fmt.Println("Public key ", miryanPublicKey)
35 | 	fmt.Println("Private Key : ", raulPrivateKey)
36 | 	fmt.Println("Public key ", raulPublicKey)
37 | 
38 | 	//Encrypt Miryan Message
39 | 	message := []byte("the code must be like a piece of music")
40 | 	label := []byte("")
41 | 	hash := sha256.New()
42 | 
43 | 	ciphertext, err := rsa.EncryptOAEP(hash, rand.Reader, raulPublicKey, message, label)
44 | 
45 | 	if err != nil {
46 | 		fmt.Println(err)
47 | 		os.Exit(1)
48 | 	}
49 | 
50 | 	fmt.Printf("OAEP encrypted [%s] to \n[%x]\n", string(message), ciphertext)
51 | 	fmt.Println()
52 | 
53 | 	// Message - Signature
54 | 	var opts rsa.PSSOptions
55 | 	opts.SaltLength = rsa.PSSSaltLengthAuto // for simple example
56 | 	PSSmessage := message
57 | 	newhash := crypto.SHA256
58 | 	pssh := newhash.New()
59 | 	pssh.Write(PSSmessage)
60 | 	hashed := pssh.Sum(nil)
61 | 
62 | 	signature, err := rsa.SignPSS(rand.Reader, miryanPrivateKey, newhash, hashed, &opts)
63 | 
64 | 	if err != nil {
65 | 		fmt.Println(err)
66 | 		os.Exit(1)
67 | 	}
68 | 
69 | 	fmt.Printf("PSS Signature : %x\n", signature)
70 | 
71 | 	// Decrypt Message
72 | 	plainText, err := rsa.DecryptOAEP(hash, rand.Reader, raulPrivateKey, ciphertext, label)
73 | 
74 | 	if err != nil {
75 | 		fmt.Println(err)
76 | 		os.Exit(1)
77 | 	}
78 | 
79 | 	fmt.Printf("OAEP decrypted [%x] to \n[%s]\n", ciphertext, plainText)
80 | 
81 | 	//Verify Signature
82 | 	err = rsa.VerifyPSS(miryanPublicKey, newhash, hashed, signature, &opts)
83 | 
84 | 	if err != nil {
85 | 		fmt.Println("Who are U? Verify Signature failed")
86 | 		os.Exit(1)
87 | 	} else {
88 | 		fmt.Println("Verify Signature successful")
89 | 	}
90 | 
91 | }
92 | 


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