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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build ignore
// Generates root_darwin_armx.go.
//
// As of iOS 8, there is no API for querying the system trusted X.509 root
// certificates. We could use SecTrustEvaluate to verify that a trust chain
// exists for a certificate, but the x509 API requires returning the entire
// chain.
//
// Apple publishes the list of trusted root certificates for iOS on
// support.apple.com. So we parse the list and extract the certificates from
// an OS X machine and embed them into the x509 package.
package main
import (
"bytes"
"crypto/x509"
"encoding/pem"
"flag"
"fmt"
"go/format"
"io/ioutil"
"log"
"math/big"
"net/http"
"os/exec"
"strings"
)
var output = flag.String("output", "root_darwin_armx.go", "file name to write")
func main() {
certs, err := selectCerts()
if err != nil {
log.Fatal(err)
}
buf := new(bytes.Buffer)
fmt.Fprintf(buf, "// Created by root_darwin_arm_gen --output %s; DO NOT EDIT\n", *output)
fmt.Fprintf(buf, "%s", header)
fmt.Fprintf(buf, "const systemRootsPEM = `\n")
for _, cert := range certs {
b := &pem.Block{
Type: "CERTIFICATE",
Bytes: cert.Raw,
}
if err := pem.Encode(buf, b); err != nil {
log.Fatal(err)
}
}
fmt.Fprintf(buf, "`")
source, err := format.Source(buf.Bytes())
if err != nil {
log.Fatal("source format error:", err)
}
if err := ioutil.WriteFile(*output, source, 0644); err != nil {
log.Fatal(err)
}
}
func selectCerts() ([]*x509.Certificate, error) {
ids, err := fetchCertIDs()
if err != nil {
return nil, err
}
scerts, err := sysCerts()
if err != nil {
return nil, err
}
var certs []*x509.Certificate
for _, id := range ids {
sn, ok := big.NewInt(0).SetString(id.serialNumber, 0) // 0x prefix selects hex
if !ok {
return nil, fmt.Errorf("invalid serial number: %q", id.serialNumber)
}
ski, ok := big.NewInt(0).SetString(id.subjectKeyID, 0)
if !ok {
return nil, fmt.Errorf("invalid Subject Key ID: %q", id.subjectKeyID)
}
for _, cert := range scerts {
if sn.Cmp(cert.SerialNumber) != 0 {
continue
}
cski := big.NewInt(0).SetBytes(cert.SubjectKeyId)
if ski.Cmp(cski) != 0 {
continue
}
certs = append(certs, cert)
break
}
}
return certs, nil
}
func sysCerts() (certs []*x509.Certificate, err error) {
cmd := exec.Command("/usr/bin/security", "find-certificate", "-a", "-p", "/System/Library/Keychains/SystemRootCertificates.keychain")
data, err := cmd.Output()
if err != nil {
return nil, err
}
for len(data) > 0 {
var block *pem.Block
block, data = pem.Decode(data)
if block == nil {
break
}
if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
continue
}
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
continue
}
certs = append(certs, cert)
}
return certs, nil
}
type certID struct {
serialNumber string
subjectKeyID string
}
// fetchCertIDs fetches IDs of iOS X509 certificates from apple.com.
func fetchCertIDs() ([]certID, error) {
resp, err := http.Get("https://support.apple.com/en-us/HT204132")
if err != nil {
return nil, err
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, err
}
text := string(body)
text = text[strings.Index(text, "<section id=trusted"):]
text = text[:strings.Index(text, "</section>")]
lines := strings.Split(text, "\n")
var ids []certID
var id certID
for i, ln := range lines {
if i == len(lines)-1 {
break
}
const sn = "Serial Number:"
if ln == sn {
id.serialNumber = "0x" + strings.Replace(strings.TrimSpace(lines[i+1]), ":", "", -1)
continue
}
if strings.HasPrefix(ln, sn) {
// extract hex value from parentheses.
id.serialNumber = ln[strings.Index(ln, "(")+1 : len(ln)-1]
continue
}
if strings.TrimSpace(ln) == "X509v3 Subject Key Identifier:" {
id.subjectKeyID = "0x" + strings.Replace(strings.TrimSpace(lines[i+1]), ":", "", -1)
ids = append(ids, id)
id = certID{}
}
}
return ids, nil
}
const header = `
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build cgo
// +build darwin
// +build arm arm64
package x509andr
func loadSystemRoots() (*CertPool, error) {
p := NewCertPool()
p.AppendCertsFromPEM([]byte(systemRootsPEM))
return p, nil
}
`
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