WIP (broken) add verify

2020-08-05 08:13:32 +00:00 · 2020-08-05 08:13:32 +00:00 · e8c50dee76
parent a1b4ad1202
commit e8c50dee76
6 changed files with 346 additions and 0 deletions
--- a/mockid/api/common.go
+++ b/mockid/api/common.go
@ -33,6 +33,12 @@ func (o *options) nextReader() io.Reader {
 	return rand.New(rand.NewSource(o.Seed))
 }

+/*
+func getJWS(r *http.Request) (*options, error) {
+
+}
+*/
+
 func getOpts(r *http.Request) (*options, error) {
 	tok := make(map[string]interface{})
 	decoder := json.NewDecoder(r.Body)
--- a/mockid/api/verify.go
+++ b/mockid/api/verify.go
@ -0,0 +1,87 @@
+package api
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"io"
+	"log"
+	"net/http"
+	"strings"
+
+	"git.coolaj86.com/coolaj86/go-mockid/xkeypairs"
+)
+
+// VerifyJWT will verify both JWT and uncompressed JWS
+func Verify(w http.ResponseWriter, r *http.Request) {
+	if "POST" != r.Method {
+		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var jws *xkeypairs.JWS
+
+	authzParts := strings.Split(r.Header.Get("Authorization"), " ")
+	lenAuthz := len(authzParts)
+	if 2 == lenAuthz {
+		jwt := authzParts[1]
+		jwsParts := strings.Split(jwt, ".")
+		if 3 == len(jwsParts) {
+			jws = &xkeypairs.JWS{
+				Protected: jwsParts[0],
+				Payload:   jwsParts[1],
+				Signature: jwsParts[2],
+			}
+		}
+	}
+
+	if nil == jws {
+		if 0 != lenAuthz {
+			http.Error(w, "Bad Request: malformed Authorization header", http.StatusBadRequest)
+			return
+		}
+		decoder := json.NewDecoder(r.Body)
+		err := decoder.Decode(&jws)
+		if nil != err && io.EOF != err {
+			log.Printf("json decode error: %s", err)
+			http.Error(w, "Bad Request: invalid JWS body", http.StatusBadRequest)
+			return
+		}
+		defer r.Body.Close()
+	}
+
+	protected, err := base64.RawURLEncoding.DecodeString(jws.Protected)
+	if nil != err {
+		http.Error(w, "Bad Request: invalid JWS header base64Url encoding", http.StatusBadRequest)
+		return
+	}
+	if err := json.Unmarshal([]byte(protected), &jws.Header); nil != err {
+		log.Printf("json decode error: %s", err)
+		http.Error(w, "Bad Request: invalid JWS header", http.StatusBadRequest)
+		return
+	}
+
+	payload, err := base64.RawURLEncoding.DecodeString(jws.Payload)
+	if nil != err {
+		http.Error(w, "Bad Request: invalid JWS payload base64Url encoding", http.StatusBadRequest)
+		return
+	}
+	if err := json.Unmarshal([]byte(payload), &jws.Claims); nil != err {
+		log.Printf("json decode error: %s", err)
+		http.Error(w, "Bad Request: invalid JWS claims", http.StatusBadRequest)
+		return
+	}
+
+	ok, err := xkeypairs.VerifyClaims(nil, jws)
+	if nil != err {
+		log.Printf("jws verify error: %s", err)
+		http.Error(w, "Bad Request: could not verify JWS claims", http.StatusBadRequest)
+		return
+	}
+	if !ok {
+		http.Error(w, "Bad Request: invalid JWS signature", http.StatusBadRequest)
+		return
+	}
+
+	b := []byte(`{"success":true}`)
+	w.Write(append(b, '\n'))
+}
--- a/mockid/mockid_test.go
+++ b/mockid/mockid_test.go
@ -64,6 +64,39 @@ func TestMain(m *testing.M) {
 //func TestSelfSignWithoutExp(t *testing.T)
 //func TestSelfSignWithJTIWithoutExp(t *testing.T)

+func TestVerifySelfSignedJWT(t *testing.T) {
+	jwt := "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.eyJleHAiOjE1OTY2MTQ3NTYsInN1YiI6ImJhbmFuYXMifQ.qHpzlglOfZMzE3CTNAUXld_wC62JTAJuoQfMaNeFa-XPtYB2Maj8_w3YmRZg_q5S6y9ToCmZ8nWd1kuMheA5qBKOUQeQH47Jts5zWLd0UBckIHo5lK4mk0bUWuiNgr7c9DY6k1DIdFaavyWCXbhFwG0X83qlMhQlPh02dDpCuU78Nn2hF3mZETQKpBIVESYtfeU1Xy3OU_am0kwcN2klLcdweOcrLx_ONfcvAGY3KiIdFiz0ViySAsQ39BiSSvoDYqOOOi41Hky67bnyZQOdalQC_95McTeXApzmGXRUE74Gj-S8c9e5it5d4QZLPaQ1JHzUKz1s7TPvThIn58NA-g"
+	client := srv.Client()
+	urlstr, _ := url.Parse(srv.URL + "/verify")
+
+	req := &http.Request{
+		Method: "POST",
+		URL:    urlstr,
+		//Body:   ioutil.NopCloser(bytes.NewReader(jws)),
+		Header: http.Header{},
+	}
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", jwt))
+	res, err := client.Do(req)
+	if nil != err {
+		t.Error(err)
+		return
+	}
+	data, err := ioutil.ReadAll(res.Body)
+	if nil != err {
+		t.Error(err)
+		return
+	}
+	if 200 != res.StatusCode {
+		log.Printf(string(data))
+		t.Error(fmt.Errorf("bad status code: %d", res.StatusCode))
+		return
+	}
+
+	log.Printf("TODO: verify, and verify non-self-signed")
+	log.Printf(string(data))
+
+}
+
 func TestSelfSign(t *testing.T) {
 	client := srv.Client()
 	//urlstr, _ := url.Parse(srv.URL + "/jose.jws.json")
--- a/mockid/route.go
+++ b/mockid/route.go
@ -192,6 +192,7 @@ func Route(jwksPrefix string, privkey keypairs.PrivateKey) http.Handler {

 	http.HandleFunc("/jose.jws.json", api.SignJWS)
 	http.HandleFunc("/jose.jws.jwt", api.SignJWT)
+	http.HandleFunc("/verify", api.Verify)

 	http.HandleFunc("/inspect_token", func(w http.ResponseWriter, r *http.Request) {
 		token := r.Header.Get("Authorization")
--- a/xkeypairs/jwk.go
+++ b/xkeypairs/jwk.go
@ -0,0 +1,70 @@
+package xkeypairs
+
+import (
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"git.rootprojects.org/root/keypairs"
+)
+
+type JWK interface {
+	marshalJWK() ([]byte, error)
+}
+
+type ECJWK struct {
+	KeyID string   `json:"kid,omitempty"`
+	Curve string   `json:"crv"`
+	X     string   `json:"x"`
+	Y     string   `json:"y"`
+	Use   []string `json:"use,omitempty"`
+	Seed  string   `json:"_seed,omitempty"`
+}
+
+func (k *ECJWK) marshalJWK() ([]byte, error) {
+	return []byte(fmt.Sprintf(`{"crv":%q,"kty":"EC","x":%q,"y":%q}`, k.Curve, k.X, k.Y)), nil
+}
+
+type RSAJWK struct {
+	KeyID string   `json:"kid,omitempty"`
+	Exp   string   `json:"e"`
+	N     string   `json"n"`
+	Use   []string `json:"use,omitempty"`
+	Seed  string   `json:"_seed,omitempty"`
+}
+
+func (k *RSAJWK) marshalJWK() ([]byte, error) {
+	return []byte(fmt.Sprintf(`{"e":%q,"kty":"RSA","n":%q}`, k.Exp, k.N)), nil
+}
+
+func ToPublicJWK(pubkey keypairs.PublicKey) JWK {
+	switch k := pubkey.Key().(type) {
+	case *ecdsa.PublicKey:
+		return ECToPublicJWK(k)
+	case *rsa.PublicKey:
+		return RSAToPublicJWK(k)
+	default:
+		panic(errors.New("impossible key type"))
+		return nil
+	}
+}
+
+// ECToPublicJWK will output the most minimal version of an EC JWK (no key id, no "use" flag, nada)
+func ECToPublicJWK(k *ecdsa.PublicKey) *ECJWK {
+	return &ECJWK{
+		Curve: k.Curve.Params().Name,
+		X:     base64.RawURLEncoding.EncodeToString(k.X.Bytes()),
+		Y:     base64.RawURLEncoding.EncodeToString(k.Y.Bytes()),
+	}
+}
+
+// RSAToPublicJWK will output the most minimal version of an RSA JWK (no key id, no "use" flag, nada)
+func RSAToPublicJWK(p *rsa.PublicKey) *RSAJWK {
+	return &RSAJWK{
+		Exp: base64.RawURLEncoding.EncodeToString(big.NewInt(int64(p.E)).Bytes()),
+		N:   base64.RawURLEncoding.EncodeToString(p.N.Bytes()),
+	}
+}
--- a/xkeypairs/verify.go
+++ b/xkeypairs/verify.go
@ -0,0 +1,149 @@
+package xkeypairs
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rsa"
+	"crypto/sha256"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"math/big"
+	mathrand "math/rand"
+
+	"git.rootprojects.org/root/keypairs"
+)
+
+func VerifyClaims(pubkey keypairs.PublicKey, jws *JWS) (bool, error) {
+	seed, _ := jws.Header["_seed"].(int64)
+	kty, _ := jws.Header["_kty"].(string)
+	kid, _ := jws.Header["kid"].(string)
+	jwkmap, hasJWK := jws.Header["jwk"].(Object)
+	//var jwk JWK = nil
+	var pub keypairs.PublicKey = nil
+	if hasJWK {
+		fmt.Println("Security TODO: did not check jws.Claims[\"sub\"] against 'jwk' thumbprint")
+		fmt.Println("Security TODO: did not check jws.Claims[\"iss\"]")
+		kty := jwkmap["kty"]
+		var err error
+		if "RSA" == kty {
+			e, _ := jwkmap["e"].(string)
+			n, _ := jwkmap["n"].(string)
+			k, _ := (&RSAJWK{
+				Exp: e,
+				N:   n,
+			}).marshalJWK()
+			pub, err = keypairs.ParseJWKPublicKey(k)
+			if nil != err {
+				return false, err
+			}
+		} else {
+			crv, _ := jwkmap["crv"].(string)
+			x, _ := jwkmap["x"].(string)
+			y, _ := jwkmap["y"].(string)
+			k, _ := (&ECJWK{
+				Curve: crv,
+				X:     x,
+				Y:     y,
+			}).marshalJWK()
+			pub, err = keypairs.ParseJWKPublicKey(k)
+			if nil != err {
+				return false, err
+			}
+		}
+	} else {
+		if "" == kid {
+			return false, errors.New("token should have 'kid' or 'jwk' in header")
+		}
+		if nil == pubkey {
+			if 0 == seed {
+				return false, errors.New("the debug API requires '_seed' to accompany 'kid'")
+			}
+			if "" == kty {
+				return false, errors.New("the debug API requires '_kty' to accompany '_seed'")
+			}
+			privkey := genPrivKey(seed, kty)
+			pub = keypairs.NewPublicKey(privkey.Public())
+		} else {
+			pub = pubkey
+		}
+		fmt.Println("Security TODO: did not check jws.Claims[\"kid\"] against thumbprint")
+	}
+
+	hash := sha256.Sum256([]byte(fmt.Sprintf("%s.%s", jws.Protected, jws.Payload)))
+	sig, err := base64.RawURLEncoding.DecodeString(jws.Signature)
+	if nil != err {
+		return false, err
+	}
+
+	return Verify(pub, hash[:], sig), nil
+}
+
+func Verify(pubkey keypairs.PublicKey, hash []byte, sig []byte) bool {
+	var verified bool
+
+	switch pub := pubkey.Key().(type) {
+	case *rsa.PublicKey:
+		// TODO keypairs.Size(key) to detect key size ?
+		//alg := "SHA256"
+		// TODO: this hasn't been tested yet
+		if err := rsa.VerifyPKCS1v15(pub, crypto.SHA256, hash, sig); nil != err {
+			verified = true
+		}
+	case *ecdsa.PublicKey:
+		r := &big.Int{}
+		r.SetBytes(sig[0:32])
+		s := &big.Int{}
+		s.SetBytes(sig[32:])
+		fmt.Println("debug: sig len:", len(sig))
+		fmt.Println("debug: r, s:", r, s)
+		verified = ecdsa.Verify(pub, hash, r, s)
+	default:
+		panic("impossible condition: non-rsa/non-ecdsa key")
+	}
+
+	return verified
+}
+
+const maxRetry = 16
+
+func genPrivKey(seed int64, kty string) keypairs.PrivateKey {
+	var privkey keypairs.PrivateKey
+
+	if "RSA" == kty {
+		keylen := 2048
+		privkey, _ = rsa.GenerateKey(nextReader(seed), keylen)
+		if 0 != seed {
+			for i := 0; i < maxRetry; i++ {
+				otherkey, _ := rsa.GenerateKey(nextReader(seed), keylen)
+				otherCmp := otherkey.D.Cmp(privkey.(*rsa.PrivateKey).D)
+				if 0 != otherCmp {
+					// There are two possible keys, choose the lesser D value
+					// See https://github.com/square/go-jose/issues/189
+					if otherCmp < 0 {
+						privkey = otherkey
+					}
+					break
+				}
+				if maxRetry == i-1 {
+					log.Printf("error: coinflip landed on heads %d times", maxRetry)
+				}
+			}
+		}
+	} else {
+		// TODO: EC keys may also suffer the same random problems in the future
+		privkey, _ = ecdsa.GenerateKey(elliptic.P256(), nextReader(seed))
+	}
+	return privkey
+}
+
+// this shananigans is only for testing and debug API stuff
+func nextReader(seed int64) io.Reader {
+	if 0 == seed {
+		return RandomReader
+	}
+	return mathrand.New(mathrand.NewSource(seed))
+}