root
/
keypairs
mirror of https://github.com/therootcompany/keypairs
2
0
Fork 0
Code Issues Releases Wiki Activity

add verify subcommand

This commit is contained in:
AJ ONeal 2020-10-02 02:44:26 -06:00
parent a560441c61
commit d42763516f
8 changed files with 559 additions and 84 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
cli_test.sh Normal file
View File

@ -0,0 +1,19 @@
#!/bin/bash
set -u
go build -mod=vendor cmd/keypairs/*.go
./keypairs gen > testkey.jwk.json 2> testpub.jwk.json
./keypairs sign --exp 1h ./testkey.jwk.json '{"foo":"bar"}' > testjwt.txt 2> testjws.json
echo ""
echo "Should pass:"
./keypairs verify ./testpub.jwk.json testjwt.txt > /dev/null
./keypairs verify ./testpub.jwk.json "$(cat testjwt.txt)" > /dev/null
./keypairs verify ./testpub.jwk.json testjws.json > /dev/null
./keypairs verify ./testpub.jwk.json "$(cat testjws.json)" > /dev/null
echo ""
echo "Should fail:"
./keypairs sign --exp -1m ./testkey.jwk.json '{"bar":"foo"}' > errjwt.txt 2> errjws.json
./keypairs verify ./testpub.jwk.json errjwt.txt > /dev/null

196
cmd/keypairs/keypairs.go
View File

@ -30,13 +30,17 @@ func usage() {
fmt.Println(" version")
fmt.Println(" gen")
fmt.Println(" sign")
fmt.Println(" verify")
fmt.Println("")
fmt.Println("Examples:")
fmt.Println(" keypairs gen -o key.jwk.json [--pub <public-key>]")
fmt.Println("")
fmt.Println(" keypairs sign --exp 15m key.jwk.json payload.json")
fmt.Println(" keypairs sign --exp 15m key.jwk.json '{ \"sub\": \"xxxx\" }'")
fmt.Println("")
//fmt.Println(" verify")
fmt.Println(" keypairs verify ./pub.jwk.json 'xxxx.yyyy.zzzz'")
// TODO fmt.Println(" keypairs verify --issuer https://example.com '{ \"sub\": \"xxxx\" }'")
fmt.Println("")
}
func ver() {
@ -65,9 +69,11 @@ func main() {
os.Exit(0)
return
case "gen":
gen(args)
gen(args[2:])
case "sign":
sign(args)
sign(args[2:])
case "verify":
verify(args[2:])
default:
usage()
os.Exit(1)
@ -94,42 +100,27 @@ func sign(args []string) {
flags := flag.NewFlagSet("sign", flag.ExitOnError)
flags.DurationVar(&exp, "exp", 0, "duration until token expires (Default 15m)")
flags.Parse(args)
if len(flags.Args()) <= 3 {
if len(flags.Args()) <= 1 {
fmt.Fprintf(os.Stderr, "Usage: keypairs sign --exp 1h <private PEM or JWK> ./payload.json\n")
os.Exit(1)
}
keyname := flags.Args()[2]
payload := flags.Args()[3]
keyname := flags.Args()[0]
payload := flags.Args()[1]
var key keypairs.PrivateKey = nil
b, err := ioutil.ReadFile(keyname)
key, err := readKey(keyname)
if nil != err {
var err2 error
key, err2 = keypairs.ParsePrivateKey([]byte(keyname))
if nil != err2 {
fmt.Fprintf(os.Stderr,
"could not read private key as file (or parse as string) %q: %s\n", keyname, err)
}
fmt.Fprintf(os.Stderr, "%v\n", err)
os.Exit(1)
return
}
if nil == key {
var err3 error
key, err3 = keypairs.ParsePrivateKey(b)
if nil != err3 {
fmt.Fprintf(os.Stderr,
"could not parse private key from file %q: %s\n", keyname, err3)
os.Exit(1)
return
}
}
if "" == payload {
// TODO should this be null? I forget
payload = "{}"
}
b, err = ioutil.ReadFile(payload)
b, err := ioutil.ReadFile(payload)
claims := map[string]interface{}{}
if nil != err {
var err2 error
@ -167,8 +158,159 @@ func sign(args []string) {
}
b, _ = json.Marshal(&jws)
fmt.Printf("JWS:\n%s\n\n", indentJSON(b))
fmt.Printf("JWT:\n%s\n\n", keypairs.JWSToJWT(jws))
fmt.Fprintf(os.Stderr, "%s\n", indentJSON(b))
fmt.Fprintf(os.Stdout, "%s\n", keypairs.JWSToJWT(jws))
}
func verify(args []string) {
flags := flag.NewFlagSet("verify", flag.ExitOnError)
flags.Usage = func() {
fmt.Println("Usage: keypairs verify <public key> <jwt-or-jwt>")
fmt.Println("")
fmt.Println(" <public key>: a File or String of an EC or RSA key in JWK or PEM format")
fmt.Println(" <jwt-or-jws>: a JWT or JWS File or String, if JWS the payload must be Base64")
fmt.Println("")
}
flags.Parse(args)
if len(flags.Args()) <= 1 {
flags.Usage()
os.Exit(1)
}
pubname := flags.Args()[0]
payload := flags.Args()[1]
pub, err := readPub(pubname)
if nil != err {
fmt.Fprintf(os.Stderr, "%v\n", err)
os.Exit(1)
return
}
jws, err := readJWS(payload)
if nil != err {
fmt.Fprintf(os.Stderr, "%v\n", err)
os.Exit(1)
return
}
b, _ := json.Marshal(&jws)
fmt.Fprintf(os.Stdout, "%s\n", indentJSON(b))
errs := keypairs.VerifyClaims(pub, jws)
if nil != errs {
fmt.Fprintf(os.Stderr, "error:\n")
for _, err := range errs {
fmt.Fprintf(os.Stderr, "\t%v\n", err)
}
os.Exit(1)
return
}
fmt.Fprintf(os.Stderr, "Signature is Valid\n")
}
func readKey(keyname string) (keypairs.PrivateKey, error) {
var key keypairs.PrivateKey = nil
// Read as file
b, err := ioutil.ReadFile(keyname)
if nil != err {
// Tis not a file! Perhaps a string?
var err2 error
key, err2 = keypairs.ParsePrivateKey([]byte(keyname))
if nil != err2 {
// Neither a valid string. Blast!
return nil, fmt.Errorf(
"could not read private key as file (or parse as string) %q:\n%s",
keyname, err2,
)
}
}
if nil == key {
var err3 error
key, err3 = keypairs.ParsePrivateKey(b)
if nil != err3 {
return nil, fmt.Errorf(
"could not parse private key from file %q:\n%s",
keyname, err3,
)
}
}
return key, nil
}
func readPub(pubname string) (keypairs.PublicKey, error) {
var pub keypairs.PublicKey = nil
// Read as file
b, err := ioutil.ReadFile(pubname)
if nil != err {
// No file? Try as string!
var err2 error
pub, err2 = keypairs.ParsePublicKey([]byte(pubname))
if nil != err2 {
return nil, fmt.Errorf(
"could not read public key as file (or parse as string) %q:\n%w",
pubname, err,
)
}
}
// Oh, it was a file.
if nil == pub {
var err3 error
pub, err3 = keypairs.ParsePublicKey(b)
if nil != err3 {
return nil, fmt.Errorf(
"could not parse public key from file %q:\n%w",
pubname, err3,
)
}
}
return pub, nil
}
func readJWS(payload string) (*keypairs.JWS, error) {
// Is it a file?
b, err := ioutil.ReadFile(payload)
if nil != err {
// Or a JWS or JWS String!?
b = []byte(payload)
}
// Either way, we have some bytes now
jws := &keypairs.JWS{}
jwt := string(b)
jwsb := []byte(jwt)
if !strings.Contains(jwt, " \t\n{}[]") {
jws = keypairs.JWTToJWS(string(b))
if nil != jws {
b, _ = json.Marshal(jws)
jwsb = (b)
}
}
// And now we have a string that may be a JWS
if err := json.Unmarshal(jwsb, &jws); nil != err {
// Nope, it's not
return nil, fmt.Errorf(
"could not read signed payload from file or string as JWT or JWS %q:\n%w",
payload, err,
)
}
if err := jws.DecodeComponents(); nil != err {
// bah! so close!
return nil, fmt.Errorf(
"could not decode the JWS Header and Claims components: %w\n%s",
err, string(jwsb),
)
}
return jws, nil
}
func marshalPriv(key keypairs.PrivateKey, keyname string) {

50
generate.go
View File

@ -11,34 +11,36 @@ import (
)
var randReader io.Reader = rand.Reader
var maxRetry = 1
var allowMocking = false
// KeyOptions are the things that we may need to know about a request to fulfill it properly
type keyOptions struct {
//Key string `json:"key"`
KeyType string `json:"kty"`
//Seed int64 `json:"-"`
KeyType string `json:"kty"`
mockSeed int64 //`json:"-"`
//SeedStr string `json:"seed"`
//Claims Object `json:"claims"`
//Header Object `json:"header"`
}
// this shananigans is only for testing and debug API stuff
func (o *keyOptions) myFooNextReader() io.Reader {
func (o *keyOptions) nextReader() io.Reader {
if allowMocking {
return o.maybeMockReader()
}
return randReader
/*
if 0 == o.Seed {
return randReader
}
return mathrand.New(mathrand.NewSource(o.Seed))
*/
}
// NewDefaultPrivateKey generates a key with reasonable strength.
// Today that means a 256-bit equivalent - either RSA 2048 or EC P-256.
func NewDefaultPrivateKey() PrivateKey {
// insecure random is okay here,
// it's just used for a coin toss
mathrand.Seed(time.Now().UnixNano())
coin := mathrand.Int()
// the idea here is that we want to make
// it dead simple to support RSA and EC
// so it shouldn't matter which is used
if 0 == coin%2 {
return newPrivateKey(&keyOptions{
KeyType: "RSA",
@ -55,29 +57,13 @@ func newPrivateKey(opts *keyOptions) PrivateKey {
if "RSA" == opts.KeyType {
keylen := 2048
privkey, _ = rsa.GenerateKey(opts.myFooNextReader(), keylen)
/*
if 0 != opts.Seed {
for i := 0; i < maxRetry; i++ {
otherkey, _ := rsa.GenerateKey(opts.myFooNextReader(), 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)
}
}
}
*/
privkey, _ = rsa.GenerateKey(opts.nextReader(), keylen)
if allowMocking {
privkey = maybeDerandomizeMockKey(privkey, keylen, opts)
}
} else {
// TODO: EC keys may also suffer the same random problems in the future
privkey, _ = ecdsa.GenerateKey(elliptic.P256(), opts.myFooNextReader())
privkey, _ = ecdsa.GenerateKey(elliptic.P256(), opts.nextReader())
}
return privkey
}

69
jwk.go Normal file
View File

@ -0,0 +1,69 @@
package keypairs
import (
"fmt"
)
// JWK abstracts EC and RSA keys
type JWK interface {
marshalJWK() ([]byte, error)
}
// ECJWK is the EC variant
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
}
// RSAJWK is the RSA variant
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
}
/*
// ToPublicJWK exposes only the public parts
func ToPublicJWK(pubkey 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()),
}
}
*/

63
jws.go Normal file
View File

@ -0,0 +1,63 @@
package keypairs
import (
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"strings"
)
// JWS is a parsed JWT, representation as signable/verifiable and human-readable parts
type JWS struct {
Header Object `json:"header"` // JSON
Claims Object `json:"claims"` // JSON
Protected string `json:"protected"` // base64
Payload string `json:"payload"` // base64
Signature string `json:"signature"` // base64
}
// JWSToJWT joins JWS parts into a JWT as {ProtectedHeader}.{SerializedPayload}.{Signature}.
func JWSToJWT(jwt *JWS) string {
return fmt.Sprintf(
"%s.%s.%s",
jwt.Protected,
jwt.Payload,
jwt.Signature,
)
}
// JWTToJWS splits the JWT into its JWS segments
func JWTToJWS(jwt string) (jws *JWS) {
jwt = strings.TrimSpace(jwt)
parts := strings.Split(jwt, ".")
if 3 != len(parts) {
return nil
}
return &JWS{
Protected: parts[0],
Payload: parts[1],
Signature: parts[2],
}
}
// DecodeComponents decodes JWS Header and Claims
func (jws *JWS) DecodeComponents() error {
protected, err := base64.RawURLEncoding.DecodeString(jws.Protected)
if nil != err {
return errors.New("invalid JWS header base64Url encoding")
}
if err := json.Unmarshal([]byte(protected), &jws.Header); nil != err {
return errors.New("invalid JWS header")
}
payload, err := base64.RawURLEncoding.DecodeString(jws.Payload)
if nil != err {
return errors.New("invalid JWS payload base64Url encoding")
}
if err := json.Unmarshal([]byte(payload), &jws.Claims); nil != err {
return errors.New("invalid JWS claims")
}
return nil
}

46
mock.go Normal file
View File

@ -0,0 +1,46 @@
package keypairs
import (
"crypto/rsa"
"io"
"log"
mathrand "math/rand"
)
// this shananigans is only for testing and debug API stuff
func (o *keyOptions) maybeMockReader() io.Reader {
if !allowMocking {
panic("mock method called when mocking is not allowed")
}
if 0 == o.mockSeed {
return randReader
}
log.Println("WARNING: MOCK: using insecure reader")
return mathrand.New(mathrand.NewSource(o.mockSeed))
}
const maxRetry = 16
func maybeDerandomizeMockKey(privkey PrivateKey, keylen int, opts *keyOptions) PrivateKey {
if 0 != opts.mockSeed {
for i := 0; i < maxRetry; i++ {
otherkey, _ := rsa.GenerateKey(opts.nextReader(), 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)
}
}
}
return privkey
}

26
sign.go
View File

@ -10,24 +10,10 @@ import (
"errors"
"fmt"
"io"
mathrand "math/rand"
mathrand "math/rand" // to be used for good, not evil
"time"
)
// randReader may be overwritten for testing
//var randReader io.Reader = rand.Reader
//var randReader = rand.Reader
// JWS is a parsed JWT, representation as signable/verifiable and human-readable parts
type JWS struct {
Header Object `json:"header"` // JSON
Claims Object `json:"claims"` // JSON
Protected string `json:"protected"` // base64
Payload string `json:"payload"` // base64
Signature string `json:"signature"` // base64
}
// Object is a type alias representing generic JSON data
type Object = map[string]interface{}
@ -149,16 +135,6 @@ func claimsToPayload(claims Object) ([]byte, error) {
return json.Marshal(claims)
}
// JWSToJWT joins JWS parts into a JWT as {ProtectedHeader}.{SerializedPayload}.{Signature}.
func JWSToJWT(jwt *JWS) string {
return fmt.Sprintf(
"%s.%s.%s",
jwt.Protected,
jwt.Payload,
jwt.Signature,
)
}
// Sign signs both RSA and ECDSA. Use `nil` or `crypto/rand.Reader` except for debugging.
func Sign(privkey PrivateKey, hash []byte, rand io.Reader) []byte {
if nil == rand {

174
verify.go Normal file
View File

@ -0,0 +1,174 @@
package keypairs
import (
"crypto"
"crypto/ecdsa"
"crypto/rsa"
"crypto/sha256"
"crypto/subtle"
"encoding/base64"
"errors"
"fmt"
"log"
"math/big"
"time"
)
// VerifyClaims will check the signature of a parsed JWT
func VerifyClaims(pubkey PublicKey, jws *JWS) (errs []error) {
kid, _ := jws.Header["kid"].(string)
jwkmap, hasJWK := jws.Header["jwk"].(Object)
//var jwk JWK = nil
seed, _ := jws.Header["_seed"].(int64)
seedf64, _ := jws.Header["_seed"].(float64)
kty, _ := jws.Header["_kty"].(string)
if 0 == seed {
seed = int64(seedf64)
}
var pub PublicKey = nil
if hasJWK {
pub, errs = selfsignCheck(jwkmap, errs)
} else {
opts := &keyOptions{mockSeed: seed, KeyType: kty}
pub, errs = pubkeyCheck(pubkey, kid, opts, errs)
}
jti, _ := jws.Claims["jti"].(string)
expf64, _ := jws.Claims["exp"].(float64)
exp := int64(expf64)
if 0 == exp {
if "" == jti {
err := errors.New("one of 'jti' or 'exp' must exist for token expiry")
errs = append(errs, err)
}
} else {
if time.Now().Unix() > exp {
err := fmt.Errorf("token expired at %d (%s)", exp, time.Unix(exp, 0))
errs = append(errs, err)
}
}
signable := fmt.Sprintf("%s.%s", jws.Protected, jws.Payload)
hash := sha256.Sum256([]byte(signable))
sig, err := base64.RawURLEncoding.DecodeString(jws.Signature)
if nil != err {
err := fmt.Errorf("could not decode signature: %w", err)
errs = append(errs, err)
return errs
}
//log.Printf("\n(Verify)\nSignable: %s", signable)
//log.Printf("Hash: %s", hash)
//log.Printf("Sig: %s", jws.Signature)
if nil == pub {
err := fmt.Errorf("token signature could not be verified")
errs = append(errs, err)
} else if !Verify(pub, hash[:], sig) {
err := fmt.Errorf("token signature is not valid")
errs = append(errs, err)
}
return errs
}
func selfsignCheck(jwkmap Object, errs []error) (PublicKey, []error) {
var pub PublicKey = nil
log.Println("Security TODO: did not check jws.Claims[\"sub\"] against 'jwk'")
log.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 = ParseJWKPublicKey(k)
if nil != err {
return nil, append(errs, 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 = ParseJWKPublicKey(k)
if nil != err {
return nil, append(errs, err)
}
}
return pub, errs
}
func pubkeyCheck(pubkey PublicKey, kid string, opts *keyOptions, errs []error) (PublicKey, []error) {
var pub PublicKey = nil
if "" == kid {
err := errors.New("token should have 'kid' or 'jwk' in header to identify the public key")
errs = append(errs, err)
}
if nil == pubkey {
if allowMocking {
if 0 == opts.mockSeed {
err := errors.New("the debug API requires '_seed' to accompany 'kid'")
errs = append(errs, err)
}
if "" == opts.KeyType {
err := errors.New("the debug API requires '_kty' to accompany '_seed'")
errs = append(errs, err)
}
if 0 == opts.mockSeed || "" == opts.KeyType {
return nil, errs
}
privkey := newPrivateKey(opts)
pub = NewPublicKey(privkey.Public())
return pub, errs
}
err := errors.New("no matching public key")
errs = append(errs, err)
} else {
pub = pubkey
}
if nil != pub && "" != kid {
if 1 != subtle.ConstantTimeCompare([]byte(kid), []byte(pub.Thumbprint())) {
err := errors.New("'kid' does not match the public key thumbprint")
errs = append(errs, err)
}
}
return pub, errs
}
// Verify will check the signature of a hash
func Verify(pubkey PublicKey, hash []byte, sig []byte) bool {
switch pub := pubkey.Key().(type) {
case *rsa.PublicKey:
//log.Printf("RSA VERIFY")
// TODO 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 {
return false
}
return true
case *ecdsa.PublicKey:
r := &big.Int{}
r.SetBytes(sig[0:32])
s := &big.Int{}
s.SetBytes(sig[32:])
return ecdsa.Verify(pub, hash, r, s)
default:
panic("impossible condition: non-rsa/non-ecdsa key")
//return false
}
}