frostfs-s3-gw/auth/center.go
2020-07-21 12:28:00 +03:00

257 lines
7.9 KiB
Go

package auth
import (
"bytes"
"context"
"crypto/ecdsa"
"crypto/rand"
"crypto/rsa"
"crypto/sha256"
"crypto/x509"
"encoding/hex"
"encoding/pem"
"io/ioutil"
"net/http"
"regexp"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws/credentials"
v4 "github.com/aws/aws-sdk-go/aws/signer/v4"
"github.com/klauspost/compress/zstd"
"github.com/nspcc-dev/neofs-api-go/refs"
"github.com/nspcc-dev/neofs-api-go/service"
crypto "github.com/nspcc-dev/neofs-crypto"
"github.com/pkg/errors"
"go.uber.org/zap"
)
var authorizationFieldRegexp = regexp.MustCompile(`AWS4-HMAC-SHA256 Credential=(?P<access_key_id>[^/]+)/(?P<date>[^/]+)/(?P<region>[^/]*)/(?P<service>[^/]+)/aws4_request, SignedHeaders=(?P<signed_header_fields>.*), Signature=(?P<v4_signature>.*)`)
const emptyStringSHA256 = `e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855`
// Center is a central app's authentication/authorization management unit.
type Center struct {
log *zap.Logger
submatcher *regexpSubmatcher
zstdEncoder *zstd.Encoder
zstdDecoder *zstd.Decoder
neofsKeys struct {
PrivateKey *ecdsa.PrivateKey
PublicKey *ecdsa.PublicKey
}
ownerID refs.OwnerID
wifString string
userAuthKeys struct {
PrivateKey *rsa.PrivateKey
PublicKey *rsa.PublicKey
}
}
// NewCenter creates an instance of AuthCenter.
func NewCenter(log *zap.Logger) *Center {
zstdEncoder, _ := zstd.NewWriter(nil)
zstdDecoder, _ := zstd.NewReader(nil)
return &Center{
log: log,
submatcher: &regexpSubmatcher{re: authorizationFieldRegexp},
zstdEncoder: zstdEncoder,
zstdDecoder: zstdDecoder,
}
}
func (center *Center) SetNeoFSKeys(key *ecdsa.PrivateKey) error {
publicKey := &key.PublicKey
oid, err := refs.NewOwnerID(publicKey)
if err != nil {
return errors.Wrap(err, "failed to get OwnerID")
}
center.neofsKeys.PrivateKey = key
wif, err := crypto.WIFEncode(key)
if err != nil {
return errors.Wrap(err, "failed to get WIF string from given key")
}
center.neofsKeys.PublicKey = publicKey
center.ownerID = oid
center.wifString = wif
return nil
}
func (center *Center) GetNeoFSKeyPrivateKey() *ecdsa.PrivateKey {
return center.neofsKeys.PrivateKey
}
func (center *Center) GetNeoFSKeyPublicKey() *ecdsa.PublicKey {
return center.neofsKeys.PublicKey
}
func (center *Center) GetOwnerID() refs.OwnerID {
return center.ownerID
}
func (center *Center) GetWIFString() string {
return center.wifString
}
func (center *Center) SetUserAuthKeys(key *rsa.PrivateKey) {
center.userAuthKeys.PrivateKey = key
center.userAuthKeys.PublicKey = &key.PublicKey
}
func (center *Center) packBearerToken(bearerToken *service.BearerTokenMsg) (string, string, error) {
data, err := bearerToken.Marshal()
if err != nil {
return "", "", errors.Wrap(err, "failed to marshal bearer token")
}
encryptedKeyID, err := encrypt(center.userAuthKeys.PublicKey, center.compress(data))
if err != nil {
return "", "", errors.Wrap(err, "failed to encrypt bearer token bytes")
}
accessKeyID := hex.EncodeToString(encryptedKeyID)
secretAccessKey := hex.EncodeToString(sha256Hash(data))
return accessKeyID, secretAccessKey, nil
}
func (center *Center) unpackBearerToken(accessKeyID string) (*service.BearerTokenMsg, string, error) {
encryptedKeyID, err := hex.DecodeString(accessKeyID)
if err != nil {
return nil, "", errors.Wrap(err, "failed to decode HEX string")
}
compressedKeyID, err := decrypt(center.userAuthKeys.PrivateKey, encryptedKeyID)
if err != nil {
return nil, "", errors.Wrap(err, "failed to decrypt key ID")
}
data, err := center.decompress(compressedKeyID)
if err != nil {
return nil, "", errors.Wrap(err, "failed to decompress key ID")
}
bearerToken := new(service.BearerTokenMsg)
if err := bearerToken.Unmarshal(data); err != nil {
return nil, "", errors.Wrap(err, "failed to unmarshal embedded bearer token")
}
secretAccessKey := hex.EncodeToString(sha256Hash(data))
return bearerToken, secretAccessKey, nil
}
func (center *Center) AuthenticationPassed(request *http.Request) (*service.BearerTokenMsg, error) {
queryValues := request.URL.Query()
if queryValues.Get("X-Amz-Algorithm") == "AWS4-HMAC-SHA256" {
return nil, errors.New("pre-signed form of request is not supported")
}
authHeaderField := request.Header["Authorization"]
if len(authHeaderField) != 1 {
return nil, errors.New("unsupported request: wrong length of Authorization header field")
}
sms1 := center.submatcher.getSubmatches(authHeaderField[0])
if len(sms1) != 6 {
return nil, errors.New("bad Authorization header field")
}
signedHeaderFieldsNames := strings.Split(sms1["signed_header_fields"], ";")
if len(signedHeaderFieldsNames) == 0 {
return nil, errors.New("wrong format of signed headers part")
}
signatureDateTime, err := time.Parse("20060102T150405Z", request.Header.Get("X-Amz-Date"))
if err != nil {
return nil, errors.Wrap(err, "failed to parse x-amz-date header field")
}
accessKeyID := sms1["access_key_id"]
bearerToken, secretAccessKey, err := center.unpackBearerToken(accessKeyID)
if err != nil {
// FIXME: Should be `return nil, errors.Wrap(err, "failed to unpack bearer token")`
center.log.Warn("Failed to unpack bearer token", zap.Error(err))
return nil, nil
}
otherRequest := request.Clone(context.TODO())
otherRequest.Header = map[string][]string{}
for hfn, hfvs := range request.Header {
for _, shfn := range signedHeaderFieldsNames {
if strings.EqualFold(hfn, shfn) {
otherRequest.Header[hfn] = hfvs
}
}
}
awsCreds := credentials.NewStaticCredentials(accessKeyID, secretAccessKey, "")
signer := v4.NewSigner(awsCreds)
body, err := readAndKeepBody(request)
if err != nil {
return nil, errors.Wrap(err, "failed to read out request body")
}
_, err = signer.Sign(otherRequest, body, sms1["service"], sms1["region"], signatureDateTime)
if err != nil {
return nil, errors.Wrap(err, "failed to sign temporary HTTP request")
}
sms2 := center.submatcher.getSubmatches(otherRequest.Header.Get("Authorization"))
if sms1["v4_signature"] != sms2["v4_signature"] {
// FIXME: Should be `return nil, errors.Wrap(err, "failed to pass authentication procedure")`
center.log.Warn("Failed to pass authentication procedure")
return nil, nil
}
return bearerToken, nil
}
func readAndKeepBody(request *http.Request) (*bytes.Reader, error) {
if request.Body == nil {
var r bytes.Reader
return &r, nil
}
payload, err := ioutil.ReadAll(request.Body)
if err != nil {
return nil, err
}
request.Body = ioutil.NopCloser(bytes.NewReader(payload))
return bytes.NewReader(payload), nil
}
func (center *Center) compress(data []byte) []byte {
return center.zstdEncoder.EncodeAll(data, make([]byte, 0, len(data)))
}
func (center *Center) decompress(data []byte) ([]byte, error) {
return center.zstdDecoder.DecodeAll(data, nil)
}
func encrypt(key *rsa.PublicKey, data []byte) ([]byte, error) {
return rsa.EncryptOAEP(sha256.New(), rand.Reader, key, data, []byte{})
}
func decrypt(key *rsa.PrivateKey, data []byte) ([]byte, error) {
return rsa.DecryptOAEP(sha256.New(), rand.Reader, key, data, []byte{})
}
func sha256Hash(data []byte) []byte {
hash := sha256.New()
hash.Write(data)
return hash.Sum(nil)
}
func ReadRSAPrivateKeyFromPEMFile(filePath string) (*rsa.PrivateKey, error) {
kbs, err := ioutil.ReadFile(filePath)
if err != nil {
return nil, errors.Wrapf(err, "failed to read file %s", filePath)
}
pemBlock, _ := pem.Decode(kbs)
if pemBlock == nil {
return nil, errors.Errorf("failed to decode PEM data from file %s", filePath)
}
rsaKey, err := x509.ParsePKCS1PrivateKey(pemBlock.Bytes)
if err != nil {
return nil, errors.Wrapf(err, "failed to parse private key bytes from pem data from file %s", filePath)
}
return rsaKey, nil
}
type regexpSubmatcher struct {
re *regexp.Regexp
}
func (resm *regexpSubmatcher) getSubmatches(target string) map[string]string {
matches := resm.re.FindStringSubmatch(target)
l := len(matches)
submatches := make(map[string]string, l)
for i, name := range resm.re.SubexpNames() {
if i > 0 && i <= l {
submatches[name] = matches[i]
}
}
return submatches
}