iWi*_*ard 1 rsa go oauth-2.0 jwt google-oauth
我需要验证谷歌id_token,一步涉及检查令牌签名.
首先,我从以下网址获取证书:https://www.googleapis.com/oauth2/v2/certs并从证书中提取模数(n)和指数(e)部分并生成公钥,然后我拆开令牌(标题,有效负载和摘要),然后我将解码header.payload
与谷歌pKey +摘要一起发送到rsa函数rsa.VerifyPKCS1v15
.
我遇到了这个验证错误: crypto/rsa: verification error
这是代码(我评论了失败的部分代码// validation here fails
):
func ValidateIDToken(auth_token string) (err error){
res, err := http.Get("https://www.googleapis.com/oauth2/v2/certs")
if err != nil {
log.Fatal(err)
return err
}
certs, err := ioutil.ReadAll(res.Body)
res.Body.Close()
if err != nil {
log.Fatal(err)
return err
}
//get modulus and exponent from the cert
var goCertificate interface{}
err = json.Unmarshal(certs, &goCertificate)
k := goCertificate.(map[string]interface{})["keys"]
j := k.([]interface{})
x := j[1]
h := x.(map[string]interface{})["n"]
g := x.(map[string]interface{})["e"]
e64 := base64.StdEncoding
//build the google pub key
nStr := h.(string)
decN, err := base64.StdEncoding.DecodeString(nStr)
if err != nil {
log.Println(err)
return
}
n := big.NewInt(0)
n.SetBytes(decN)
eStr := g.(string)
decE, err := base64.StdEncoding.DecodeString(eStr)
if err != nil {
log.Println(err)
return
}
var eBytes []byte
if len(decE) < 8 {
eBytes = make([]byte, 8-len(decE), 8)
eBytes = append(eBytes, decE...)
} else {
eBytes = decE
}
eReader := bytes.NewReader(eBytes)
var e uint64
err = binary.Read(eReader, binary.BigEndian, &e)
if err != nil {
log.Println(err)
return
}
pKey := rsa.PublicKey{N: n, E: int(e)}
w := strings.SplitAfter(auth_token, ".")
for i, val := range w {
w[i] = strings.Trim(val, ".")
}
y := w[0:2]
//Join just the first two parts, the header and the payload without the signature
o := strings.Join(y, ".")
headerOauth := DecodeB64(nil,[]byte(w[0]),e64)
inblockOauth := DecodeB64(nil,[]byte(w[1]),e64)
toHash := string(headerOauth) + "}." + string(inblockOauth)
digestOauth := DecodeB64(nil, []byte(w[2]),e64)
hasherOauth := sha256.New()
hasherOauth.Write([]byte(toHash))
// validation here fails
err = rsa.VerifyPKCS1v15(&pKey,crypto.SHA256,hasherOauth.Sum(nil),digestOauth)
if err != nil {
log.Printf("Error verifying key %s",err.Error())
return err
}
return err
}
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更新1: 这是包含头和有效负载的哈希var:
{"alg":"RS256","kid":"d91c503452d0f8849200a321ffbf7dea76f9371d"}.{"iss":"accounts.google.com","sub":"104869993929250743503","azp":"client_email_till_@.apps.googleusercontent.com","email":"test@test.hr","at_hash":"KAm1M0g-ssMkdjds7jkbVQ","email_verified":true,"aud":client_email_till_@.apps.googleusercontent.com","hd":"test.hr","iat":1412246551,"exp":1412250451}
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更新2: 感谢@Florent Morselli的回复,我再次尝试了它失败了,我这次B64解码只有第三部分(签名)但错误仍然存在,有人用他们的auth_token测试它,只需要放置ID令牌在代码下面的auth_token变量中,让我知道它是否有效,谢谢.
package main
import(
"strings"
"encoding/binary"
"errors"
"fmt"
"log"
"encoding/base64"
"io/ioutil"
"crypto"
"crypto/sha256"
"crypto/rsa"
"bytes"
"encoding/json"
"net/http"
"math/big"
)
func main() {
auth_token := ""
w := strings.SplitAfter(auth_token, ".")
for i, val := range w {
w[i] = strings.Trim(val, ".")
}
headerOauth, err := base64.URLEncoding.DecodeString(w[0])
res, err := http.Get("https://www.googleapis.com/oauth2/v2/certs")
if err != nil {
fmt.Println(err)
}
certs, err := ioutil.ReadAll(res.Body)
res.Body.Close()
if err != nil {
fmt.Println(err)
}
//extract kid from token header
var header interface{}
err = json.Unmarshal([]byte(string(headerOauth)+"}"), &header)
token_kid := header.(map[string]interface{})["kid"]
fmt.Println("By 1")
//get modulus and exponent from the cert
var goCertificate interface{}
err = json.Unmarshal(certs, &goCertificate)
//k := goCertificate.(map[string]interface{})[token_kid.(string)]
k := goCertificate.(map[string]interface{})["keys"]
///*mod & exp part
j := k.([]interface{})
x := j[0]
if j[0].(map[string]interface{})["kid"] == token_kid {
x = j[0]
}else{
if j[1].(map[string]interface{})["kid"] == token_kid {
x = j[1]
}else{
errors.New("Token is not valid, kid from token and certificate don't match")
}
}
h := x.(map[string]interface{})["n"]
g := x.(map[string]interface{})["e"]
//build the google pub key
nStr := h.(string)
decN, err := base64.URLEncoding.DecodeString(nStr)
if err != nil {
fmt.Println(err)
return
}
n := big.NewInt(0)
n.SetBytes(decN)
eStr := g.(string)
decE, err := base64.URLEncoding.DecodeString(eStr)
if err != nil {
fmt.Println(err)
return
}
var eBytes []byte
if len(decE) < 8 {
eBytes = make([]byte, 8-len(decE), 8)
eBytes = append(eBytes, decE...)
} else {
eBytes = decE
}
eReader := bytes.NewReader(eBytes)
var e uint64
err = binary.Read(eReader, binary.BigEndian, &e)
if err != nil {
log.Println(err)
return
}
pKey := rsa.PublicKey{N: n, E: int(e)}
//inblockOauth := base64.URLEncoding.DecodeString(w[1])
toHash := w[0] + "." + w[1]
digestOauth, err := base64.URLEncoding.DecodeString(w[2])
hasherOauth := sha256.New()
hasherOauth.Write([]byte(toHash))
// verification here fails
err = rsa.VerifyPKCS1v15(&pKey,crypto.SHA256,hasherOauth.Sum(nil),digestOauth)
if err != nil {
fmt.Printf("Error verifying key %s",err.Error())
}
}
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正如聊天中所解释的那样,问题是Base64解码器如果缺少"="则无法解码标头和签名.
您只需使用以下代码添加它们:
if m := len(h_) % 4; m != 0 {
h_ += strings.Repeat("=", 4-m)
}
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这是完整的代码:
package main
import(
"strings"
"encoding/binary"
"errors"
"fmt"
"log"
"encoding/base64"
"io/ioutil"
"crypto"
"crypto/sha256"
"crypto/rsa"
"bytes"
"encoding/json"
"net/http"
"math/big"
)
func main() {
auth_token := ""
w := strings.Split(auth_token, ".")
h_, s_ := w[0], w[2]
if m := len(h_) % 4; m != 0 {
h_ += strings.Repeat("=", 4-m)
}
if m := len(s_) % 4; m != 0 {
s_ += strings.Repeat("=", 4-m)
}
headerOauth, err := base64.URLEncoding.DecodeString(h_)
res, err := http.Get("https://www.googleapis.com/oauth2/v2/certs")
if err != nil {
fmt.Println(err)
}
certs, err := ioutil.ReadAll(res.Body)
res.Body.Close()
if err != nil {
fmt.Println(err)
}
//extract kid from token header
var header interface{}
err = json.Unmarshal([]byte(string(headerOauth)), &header)
token_kid := header.(map[string]interface{})["kid"]
fmt.Println("By 1")
//get modulus and exponent from the cert
var goCertificate interface{}
err = json.Unmarshal(certs, &goCertificate)
//k := goCertificate.(map[string]interface{})[token_kid.(string)]
k := goCertificate.(map[string]interface{})["keys"]
///*mod & exp part
j := k.([]interface{})
x := j[0]
if j[0].(map[string]interface{})["kid"] == token_kid {
x = j[0]
}else{
if j[1].(map[string]interface{})["kid"] == token_kid {
x = j[1]
}else{
errors.New("Token is not valid, kid from token and certificate don't match")
}
}
h := x.(map[string]interface{})["n"]
g := x.(map[string]interface{})["e"]
//build the google pub key
nStr := h.(string)
decN, err := base64.URLEncoding.DecodeString(nStr)
if err != nil {
fmt.Println(err)
return
}
n := big.NewInt(0)
n.SetBytes(decN)
eStr := g.(string)
decE, err := base64.URLEncoding.DecodeString(eStr)
if err != nil {
fmt.Println(err)
return
}
var eBytes []byte
if len(decE) < 8 {
eBytes = make([]byte, 8-len(decE), 8)
eBytes = append(eBytes, decE...)
} else {
eBytes = decE
}
eReader := bytes.NewReader(eBytes)
var e uint64
err = binary.Read(eReader, binary.BigEndian, &e)
if err != nil {
log.Println(err)
return
}
pKey := rsa.PublicKey{N: n, E: int(e)}
//inblockOauth := base64.URLEncoding.DecodeString(w[1])
toHash := w[0] + "." + w[1]
digestOauth, err := base64.URLEncoding.DecodeString(s_)
hasherOauth := sha256.New()
hasherOauth.Write([]byte(toHash))
// verification of the signature
err = rsa.VerifyPKCS1v15(&pKey,crypto.SHA256,hasherOauth.Sum(nil),digestOauth)
if err != nil {
fmt.Printf("Error verifying key %s",err.Error())
}
fmt.Printf("OK!")
}
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