Reorganize directory structures

Signed-off-by: Sean Du <do4suki@gmail.com>

pkg/encrypt/rsa.go

@@ -0,0 +1,174 @@
+package encrypt
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha1"
+	"crypto/x509"
+	"encoding/pem"
+	"honoka-chan/config"
+	"os"
+	"path/filepath"
+	"runtime"
+)
+
+func RSAGen(bits int) {
+	//get current path
+	_, currentpath, _, _ := runtime.Caller(0)
+	currentpath = filepath.Dir(currentpath)
+
+	//----------------------------------------------private key
+
+	// GenerateKey generates an RSA keypair of the given bit size using the
+	// random source random (for example, crypto/rand.Reader).
+	privateKey, err := rsa.GenerateKey(rand.Reader, bits)
+	if err != nil {
+		panic(err)
+	}
+
+	//serialize privatekey to ASN.1 der by x509.MarshalPKCS8PrivateKey
+	x509privatekey, err := x509.MarshalPKCS8PrivateKey(privateKey)
+	if err != nil {
+		panic(err)
+	}
+
+	//encode x509 to pem and save to file
+	//1. create privatefile
+	privatekeyfile, err := os.Create(config.PrivateKeyPath)
+	if err != nil {
+		panic(err)
+	}
+	defer privatekeyfile.Close()
+	//2. new a pem block struct object
+	privatekeyblock := pem.Block{
+		Type:    "PRIVATE KEY",
+		Headers: nil,
+		Bytes:   x509privatekey,
+	}
+	//3. save to file
+	pem.Encode(privatekeyfile, &privatekeyblock)
+
+	//----------------------------------------------public key
+
+	//get public key
+	publickey := privateKey.PublicKey
+	//serialize publickey to ASN.1 der by x509.MarshalPKCS8PublicKey
+	x509publickey, _ := x509.MarshalPKIXPublicKey(&publickey)
+
+	//encode x509 to pem and save to file
+	//1. create publickeyfile
+	publickeyfile, err := os.Create(config.PublicKeyPath)
+	if err != nil {
+		panic(err)
+	}
+	defer publickeyfile.Close()
+
+	//2. new a pem block struct object
+	publickeyblock := pem.Block{
+		Type:    "PUBLIC KEY",
+		Headers: nil,
+		Bytes:   x509publickey,
+	}
+
+	//3. save to file
+	pem.Encode(publickeyfile, &publickeyblock)
+}
+
+func RSAEncrypt(plainText []byte, publickeypath string) []byte {
+	//open publickeyfile
+	publickeyfile, err := os.Open(publickeypath)
+	if err != nil {
+		panic(err)
+	}
+	defer publickeyfile.Close()
+
+	//get publickeyfile info
+	publickeyfileInfo, _ := publickeyfile.Stat()
+
+	//read publickeyfile content
+	//1. make size
+	buf := make([]byte, publickeyfileInfo.Size())
+	//2. read file to buf
+	publickeyfile.Read(buf)
+	//3. decode pem
+	publickeyDecodeBlock, _ := pem.Decode(buf)
+	//4. x509 decode
+	publicKeyInterface, err := x509.ParsePKIXPublicKey(publickeyDecodeBlock.Bytes)
+	if err != nil {
+		panic(err)
+	}
+	//assert
+	publicKey := publicKeyInterface.(*rsa.PublicKey)
+
+	//encrypt plainText
+	cipherText, err := rsa.EncryptPKCS1v15(rand.Reader, publicKey, plainText)
+	if err != nil {
+		panic(err)
+	}
+
+	return cipherText
+}
+
+func RSADecrypt(cipherText []byte) []byte {
+	//open privatekeyfile
+	privatekeyfile, err := os.Open(config.PrivateKeyPath)
+	if err != nil {
+		panic(err)
+	}
+	defer privatekeyfile.Close()
+	//get privatekeyfile content
+	privatekeyinfo, _ := privatekeyfile.Stat()
+	buf := make([]byte, privatekeyinfo.Size())
+	privatekeyfile.Read(buf)
+	//pem decode
+	privatekeyblock, _ := pem.Decode(buf)
+	//X509 decode
+	parseKey, err := x509.ParsePKCS8PrivateKey(privatekeyblock.Bytes)
+	if err != nil {
+		panic(err)
+	}
+	privateKey := parseKey.(*rsa.PrivateKey)
+	//decrypt the cipher
+	plainText, err := rsa.DecryptPKCS1v15(rand.Reader, privateKey, cipherText)
+	if err != nil {
+		panic(err)
+	}
+
+	return plainText
+}
+
+func RSASignSHA1(cipherText []byte) []byte {
+	//open privatekeyfile
+	privatekeyfile, err := os.Open(config.PrivateKeyPath)
+	if err != nil {
+		panic(err)
+	}
+	defer privatekeyfile.Close()
+	//get privatekeyfile content
+	privatekeyinfo, _ := privatekeyfile.Stat()
+	buf := make([]byte, privatekeyinfo.Size())
+	privatekeyfile.Read(buf)
+	//pem decode
+	privatekeyblock, _ := pem.Decode(buf)
+	//X509 decode
+	parseKey, err := x509.ParsePKCS8PrivateKey(privatekeyblock.Bytes)
+	if err != nil {
+		panic(err)
+	}
+	privateKey := parseKey.(*rsa.PrivateKey)
+
+	msgHash := sha1.New()
+	_, err = msgHash.Write(cipherText)
+	if err != nil {
+		panic(err)
+	}
+	msgHashSum := msgHash.Sum(nil)
+
+	signature, err := rsa.SignPSS(rand.Reader, privateKey, crypto.SHA1, msgHashSum, nil)
+	if err != nil {
+		panic(err)
+	}
+
+	return signature
+}