frostfs-s3-gw/api/auth/center.go
Roman Khimov dbe65ae602 creds: move credential management into s3 gate
Mostly taken from old SDK (abe47687cd11266f946cad57f07572cc10c67226), but
error handling adapted to eliminate pkg/errors and internal packages.

Signed-off-by: Roman Khimov <roman@nspcc.ru>
2021-05-25 23:00:19 +03:00

134 lines
3.6 KiB
Go

package auth
import (
"context"
"errors"
"fmt"
"io"
"net/http"
"regexp"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws/credentials"
v4 "github.com/aws/aws-sdk-go/aws/signer/v4"
sdk "github.com/nspcc-dev/cdn-sdk"
"github.com/nspcc-dev/neofs-s3-gw/creds/bearer"
"github.com/nspcc-dev/neofs-s3-gw/creds/hcs"
"github.com/nspcc-dev/neofs-api-go/pkg/object"
"github.com/nspcc-dev/neofs-api-go/pkg/token"
"github.com/nspcc-dev/neofs-s3-gw/authmate"
"go.uber.org/zap"
)
var authorizationFieldRegexp = regexp.MustCompile(`AWS4-HMAC-SHA256 Credential=(?P<access_key_id_cid>[^/]+)/(?P<access_key_id_oid>[^/]+)/(?P<date>[^/]+)/(?P<region>[^/]*)/(?P<service>[^/]+)/aws4_request,\s*SignedHeaders=(?P<signed_header_fields>.+),\s*Signature=(?P<v4_signature>.+)`)
type (
// Center is a user authentication interface.
Center interface {
Authenticate(request *http.Request) (*token.BearerToken, error)
}
center struct {
reg *regexpSubmatcher
cli bearer.Credentials
}
// Params stores node connection parameters.
Params struct {
Client sdk.Client
Logger *zap.Logger
Credential hcs.Credentials
}
prs int
)
func (p prs) Read(_ []byte) (n int, err error) {
panic("implement me")
}
func (p prs) Seek(_ int64, _ int) (int64, error) {
panic("implement me")
}
var _ io.ReadSeeker = prs(0)
// New creates an instance of AuthCenter.
func New(obj sdk.ObjectClient, key hcs.PrivateKey) Center {
return &center{
cli: bearer.New(obj, key),
reg: &regexpSubmatcher{re: authorizationFieldRegexp},
}
}
func (c *center) Authenticate(r *http.Request) (*token.BearerToken, error) {
queryValues := r.URL.Query()
if queryValues.Get("X-Amz-Algorithm") == "AWS4-HMAC-SHA256" {
return nil, errors.New("pre-signed form of request is not supported")
}
authHeaderField := r.Header["Authorization"]
if len(authHeaderField) != 1 {
return nil, errors.New("unsupported request: wrong length of Authorization header field")
}
sms1 := c.reg.getSubmatches(authHeaderField[0])
if len(sms1) != 7 {
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", r.Header.Get("X-Amz-Date"))
if err != nil {
return nil, fmt.Errorf("failed to parse x-amz-date header field: %w", err)
}
accessKeyID := fmt.Sprintf("%s/%s", sms1["access_key_id_cid"], sms1["access_key_id_oid"])
address := object.NewAddress()
if err = address.Parse(accessKeyID); err != nil {
return nil, fmt.Errorf("could not parse AccessBox address: %s : %w", accessKeyID, err)
}
tkn, err := c.cli.Get(r.Context(), address)
if err != nil {
return nil, err
}
secret, err := authmate.BearerToAccessKey(tkn)
if err != nil {
return nil, err
}
otherRequest := r.Clone(context.TODO())
otherRequest.Header = make(http.Header)
for key, val := range r.Header {
for _, name := range signedHeaderFieldsNames {
if strings.EqualFold(key, name) {
otherRequest.Header[key] = val
}
}
}
awsCreds := credentials.NewStaticCredentials(accessKeyID, secret, "")
signer := v4.NewSigner(awsCreds)
signer.DisableURIPathEscaping = true
// body not required
if _, err := signer.Sign(otherRequest, nil, sms1["service"], sms1["region"], signatureDateTime); err != nil {
return nil, fmt.Errorf("failed to sign temporary HTTP request: %w", err)
}
sms2 := c.reg.getSubmatches(otherRequest.Header.Get("Authorization"))
if sms1["v4_signature"] != sms2["v4_signature"] {
return nil, errors.New("failed to pass authentication procedure")
}
return tkn, nil
}