forked from intelsdi-x/snap
/
snapTLS.go
136 lines (115 loc) · 2.93 KB
/
snapTLS.go
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/*
http://www.apache.org/licenses/LICENSE-2.0.txt
Copyright 2015 Intel Corporation
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package rest
import (
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
"io/ioutil"
"math/big"
"os"
"time"
)
type snapTLS struct {
cert, key string
}
func newtls(certPath, keyPath string) (*snapTLS, error) {
t := &snapTLS{}
if certPath != "" && keyPath != "" {
cert, err := os.Open(certPath)
if err != nil {
return nil, err
}
_, err = os.Open(keyPath)
if err != nil {
return nil, err
}
rest, err := ioutil.ReadAll(cert)
if err != nil {
return nil, err
}
// test that given keychain is valid
var block *pem.Block
for {
block, rest = pem.Decode(rest)
if block == nil {
return nil, ErrBadCert
}
_, err := x509.ParseCertificate(block.Bytes)
if err != nil {
return nil, err
}
if len(rest) == 0 {
break
}
}
t.cert = certPath
t.key = keyPath
} else {
err := generateCert(t)
if err != nil {
return nil, err
}
}
return t, nil
}
func generateCert(t *snapTLS) error {
// good for 1 year
notBefore := time.Now()
notAfter := notBefore.Add(time.Hour * 24 * 365)
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
if err != nil {
return err
}
temp := &x509.Certificate{
SerialNumber: serialNumber,
Subject: pkix.Name{
Organization: []string{"Local snap Agent"},
},
DNSNames: []string{"localhost"},
NotBefore: notBefore,
NotAfter: notAfter,
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
BasicConstraintsValid: true,
}
priv, err := rsa.GenerateKey(rand.Reader, 1024)
if err != nil {
return err
}
cbytes, err := x509.CreateCertificate(rand.Reader, temp, temp, &priv.PublicKey, priv)
if err != nil {
return err
}
certPath := os.TempDir() + "/cert.pem"
keyPath := os.TempDir() + "/key.pem"
cout, err := os.Create(certPath)
if err != nil {
return err
}
pem.Encode(cout, &pem.Block{Type: "CERTIFICATE", Bytes: cbytes})
cout.Close()
kout, err := os.OpenFile(keyPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
return err
}
pem.Encode(kout, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
kout.Close()
t.cert = certPath
t.key = keyPath
return nil
}