Files
versitygw/s3api/middlewares/authentication.go

246 lines
8.1 KiB
Go

// Copyright 2023 Versity Software
// This file is licensed under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
package middlewares
import (
"crypto/sha256"
"encoding/hex"
"fmt"
"math"
"net/http"
"os"
"strings"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
"github.com/aws/smithy-go/logging"
"github.com/gofiber/fiber/v2"
"github.com/versity/versitygw/auth"
"github.com/versity/versitygw/s3api/controllers"
"github.com/versity/versitygw/s3api/utils"
"github.com/versity/versitygw/s3err"
"github.com/versity/versitygw/s3log"
)
const (
iso8601Format = "20060102T150405Z"
YYYYMMDD = "20060102"
)
type RootUserConfig struct {
Access string
Secret string
}
func VerifyV4Signature(root RootUserConfig, iam auth.IAMService, logger s3log.AuditLogger, region string, debug bool) fiber.Handler {
acct := accounts{root: root, iam: iam}
return func(ctx *fiber.Ctx) error {
ctx.Locals("region", region)
ctx.Locals("startTime", time.Now())
authorization := ctx.Get("Authorization")
if authorization == "" {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrAuthHeaderEmpty), &controllers.MetaOpts{Logger: logger})
}
// Check the signature version
authParts := strings.Split(authorization, ",")
for i, el := range authParts {
authParts[i] = strings.TrimSpace(el)
}
if len(authParts) != 3 {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrMissingFields), &controllers.MetaOpts{Logger: logger})
}
startParts := strings.Split(authParts[0], " ")
if startParts[0] != "AWS4-HMAC-SHA256" {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrSignatureVersionNotSupported), &controllers.MetaOpts{Logger: logger})
}
credKv := strings.Split(startParts[1], "=")
if len(credKv) != 2 {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrCredMalformed), &controllers.MetaOpts{Logger: logger})
}
// Credential variables validation
creds := strings.Split(credKv[1], "/")
if len(creds) != 5 {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrCredMalformed), &controllers.MetaOpts{Logger: logger})
}
if creds[4] != "aws4_request" {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrSignatureTerminationStr), &controllers.MetaOpts{Logger: logger})
}
if creds[3] != "s3" {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrSignatureIncorrService), &controllers.MetaOpts{Logger: logger})
}
if creds[2] != region {
return controllers.SendResponse(ctx, s3err.APIError{
Code: "SignatureDoesNotMatch",
Description: fmt.Sprintf("Credential should be scoped to a valid Region, not %v", creds[2]),
HTTPStatusCode: http.StatusForbidden,
}, &controllers.MetaOpts{Logger: logger})
}
ctx.Locals("isRoot", creds[0] == root.Access)
_, err := time.Parse(YYYYMMDD, creds[1])
if err != nil {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrSignatureDateDoesNotMatch), &controllers.MetaOpts{Logger: logger})
}
signHdrKv := strings.Split(authParts[1], "=")
if len(signHdrKv) != 2 {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrCredMalformed), &controllers.MetaOpts{Logger: logger})
}
signedHdrs := strings.Split(signHdrKv[1], ";")
account, err := acct.getAccount(creds[0])
if err == auth.ErrNoSuchUser {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrInvalidAccessKeyID), &controllers.MetaOpts{Logger: logger})
}
if err != nil {
return controllers.SendResponse(ctx, err, &controllers.MetaOpts{Logger: logger})
}
ctx.Locals("account", account)
// Check X-Amz-Date header
date := ctx.Get("X-Amz-Date")
if date == "" {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrMissingDateHeader), &controllers.MetaOpts{Logger: logger})
}
// Parse the date and check the date validity
tdate, err := time.Parse(iso8601Format, date)
if err != nil {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrMalformedDate), &controllers.MetaOpts{Logger: logger})
}
if date[:8] != creds[1] {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrSignatureDateDoesNotMatch), &controllers.MetaOpts{Logger: logger})
}
// Validate the dates difference
err = validateDate(tdate)
if err != nil {
return controllers.SendResponse(ctx, err, &controllers.MetaOpts{Logger: logger})
}
hashPayloadHeader := ctx.Get("X-Amz-Content-Sha256")
ok := isSpecialPayload(hashPayloadHeader)
if !ok {
// Calculate the hash of the request payload
hashedPayload := sha256.Sum256(ctx.Body())
hexPayload := hex.EncodeToString(hashedPayload[:])
// Compare the calculated hash with the hash provided
if hashPayloadHeader != hexPayload {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrContentSHA256Mismatch), &controllers.MetaOpts{Logger: logger})
}
}
// Create a new http request instance from fasthttp request
req, err := utils.CreateHttpRequestFromCtx(ctx, signedHdrs)
if err != nil {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrInternalError), &controllers.MetaOpts{Logger: logger})
}
signer := v4.NewSigner()
signErr := signer.SignHTTP(req.Context(), aws.Credentials{
AccessKeyID: creds[0],
SecretAccessKey: account.Secret,
}, req, hashPayloadHeader, creds[3], region, tdate, func(options *v4.SignerOptions) {
options.DisableURIPathEscaping = true
if debug {
options.LogSigning = true
options.Logger = logging.NewStandardLogger(os.Stderr)
}
})
if signErr != nil {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrInternalError), &controllers.MetaOpts{Logger: logger})
}
parts := strings.Split(req.Header.Get("Authorization"), " ")
if len(parts) < 4 {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrMissingFields), &controllers.MetaOpts{Logger: logger})
}
calculatedSign := strings.Split(parts[3], "=")[1]
expectedSign := strings.Split(authParts[2], "=")[1]
if expectedSign != calculatedSign {
return controllers.SendResponse(ctx, s3err.GetAPIError(s3err.ErrSignatureDoesNotMatch), &controllers.MetaOpts{Logger: logger})
}
return ctx.Next()
}
}
type accounts struct {
root RootUserConfig
iam auth.IAMService
}
func (a accounts) getAccount(access string) (auth.Account, error) {
if access == a.root.Access {
return auth.Account{
Access: a.root.Access,
Secret: a.root.Secret,
Role: "admin",
}, nil
}
return a.iam.GetUserAccount(access)
}
func isSpecialPayload(str string) bool {
specialValues := map[string]bool{
"UNSIGNED-PAYLOAD": true,
"STREAMING-UNSIGNED-PAYLOAD-TRAILER": true,
"STREAMING-AWS4-HMAC-SHA256-PAYLOAD": true,
"STREAMING-AWS4-HMAC-SHA256-PAYLOAD-TRAILER": true,
"STREAMING-AWS4-ECDSA-P256-SHA256-PAYLOAD": true,
"STREAMING-AWS4-ECDSA-P256-SHA256-PAYLOAD-TRAILER": true,
}
return specialValues[str]
}
func validateDate(date time.Time) error {
now := time.Now().UTC()
diff := date.Unix() - now.Unix()
// Checks the dates difference to be less than a minute
if math.Abs(float64(diff)) > 60 {
if diff > 0 {
return s3err.APIError{
Code: "SignatureDoesNotMatch",
Description: fmt.Sprintf("Signature not yet current: %s is still later than %s", date.Format(iso8601Format), now.Format(iso8601Format)),
HTTPStatusCode: http.StatusForbidden,
}
} else {
return s3err.APIError{
Code: "SignatureDoesNotMatch",
Description: fmt.Sprintf("Signature expired: %s is now earlier than %s", date.Format(iso8601Format), now.Format(iso8601Format)),
HTTPStatusCode: http.StatusForbidden,
}
}
}
return nil
}