minio/pkg/server/api/signature.go

119 lines
3.6 KiB
Go

/*
* Minio Cloud Storage, (C) 2015 Minio, Inc.
*
* 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 api
import (
"errors"
"net/http"
"strings"
"github.com/minio/minio/pkg/auth"
"github.com/minio/minio/pkg/donut"
"github.com/minio/minio/pkg/probe"
)
const (
authHeaderPrefix = "AWS4-HMAC-SHA256"
)
// getCredentialsFromAuth parse credentials tag from authorization value
func getCredentialsFromAuth(authValue string) ([]string, *probe.Error) {
if authValue == "" {
return nil, probe.NewError(errMissingAuthHeaderValue)
}
authFields := strings.Split(strings.TrimSpace(authValue), ",")
if len(authFields) != 3 {
return nil, probe.NewError(errInvalidAuthHeaderValue)
}
authPrefixFields := strings.Fields(authFields[0])
if len(authPrefixFields) != 2 {
return nil, probe.NewError(errMissingFieldsAuthHeader)
}
if authPrefixFields[0] != authHeaderPrefix {
return nil, probe.NewError(errInvalidAuthHeaderPrefix)
}
credentials := strings.Split(strings.TrimSpace(authPrefixFields[1]), "=")
if len(credentials) != 2 {
return nil, probe.NewError(errMissingFieldsCredentialTag)
}
if len(strings.Split(strings.TrimSpace(authFields[1]), "=")) != 2 {
return nil, probe.NewError(errMissingFieldsSignedHeadersTag)
}
if len(strings.Split(strings.TrimSpace(authFields[2]), "=")) != 2 {
return nil, probe.NewError(errMissingFieldsSignatureTag)
}
credentialElements := strings.Split(strings.TrimSpace(credentials[1]), "/")
if len(credentialElements) != 5 {
return nil, probe.NewError(errCredentialTagMalformed)
}
return credentialElements, nil
}
// verify if authHeader value has valid region
func isValidRegion(authHeaderValue string) *probe.Error {
credentialElements, err := getCredentialsFromAuth(authHeaderValue)
if err != nil {
return err.Trace()
}
region := credentialElements[2]
if region != "milkyway" {
return probe.NewError(errInvalidRegion)
}
return nil
}
// stripAccessKeyID - strip only access key id from auth header
func stripAccessKeyID(authHeaderValue string) (string, *probe.Error) {
if err := isValidRegion(authHeaderValue); err != nil {
return "", err.Trace()
}
credentialElements, err := getCredentialsFromAuth(authHeaderValue)
if err != nil {
return "", err.Trace()
}
accessKeyID := credentialElements[0]
if !auth.IsValidAccessKey(accessKeyID) {
return "", probe.NewError(errAccessKeyIDInvalid)
}
return accessKeyID, nil
}
// initSignatureV4 initializing signature verification
func initSignatureV4(req *http.Request) (*donut.Signature, *probe.Error) {
// strip auth from authorization header
authHeaderValue := req.Header.Get("Authorization")
accessKeyID, err := stripAccessKeyID(authHeaderValue)
if err != nil {
return nil, err.Trace()
}
authConfig, err := auth.LoadConfig()
if err != nil {
return nil, err.Trace()
}
for _, user := range authConfig.Users {
if user.AccessKeyID == accessKeyID {
signature := &donut.Signature{
AccessKeyID: user.AccessKeyID,
SecretAccessKey: user.SecretAccessKey,
AuthHeader: authHeaderValue,
Request: req,
}
return signature, nil
}
}
return nil, probe.NewError(errors.New("AccessKeyID not found"))
}