-/*
-Permissions management on Arvados locator hashes.
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
-The permissions structure for Arvados is as follows (from
-https://arvados.org/issues/2328)
-
-A Keep locator string has the following format:
-
- [hash]+[size]+A[signature]@[timestamp]
-
-The "signature" string here is a cryptographic hash, expressed as a
-string of hexadecimal digits, and timestamp is a 32-bit Unix timestamp
-expressed as a hexadecimal number. e.g.:
-
- acbd18db4cc2f85cedef654fccc4a4d8+3+A257f3f5f5f0a4e4626a18fc74bd42ec34dcb228a@7fffffff
-
-The signature represents a guarantee that this locator was generated
-by either Keep or the API server for use with the supplied API token.
-If a request to Keep includes a locator with a valid signature and is
-accompanied by the proper API token, the user has permission to GET
-that object.
-
-The signature may be generated either by Keep (after the user writes a
-block) or by the API server (if the user has can_read permission on
-the specified object). Keep and API server share a secret that is used
-to generate signatures.
-
-To verify a permission hint, Keep generates a new hint for the
-requested object (using the locator string, the timestamp, the
-permission secret and the user's API token, which must appear in the
-request headers) and compares it against the hint included in the
-request. If the permissions do not match, or if the API token is not
-present, Keep returns a 401 error.
-*/
-
-package main
+package keepstore
import (
- "crypto/hmac"
- "crypto/sha1"
- "fmt"
- "regexp"
- "strconv"
- "strings"
"time"
-)
-// The PermissionSecret is the secret key used to generate SHA1
-// digests for permission hints. apiserver and Keep must use the same
-// key.
-var PermissionSecret []byte
-
-// MakePermSignature returns a string representing the signed permission
-// hint for the blob identified by blobHash, apiToken and expiration timestamp.
-func MakePermSignature(blobHash string, apiToken string, expiry string) string {
- hmac := hmac.New(sha1.New, PermissionSecret)
- hmac.Write([]byte(blobHash))
- hmac.Write([]byte("@"))
- hmac.Write([]byte(apiToken))
- hmac.Write([]byte("@"))
- hmac.Write([]byte(expiry))
- digest := hmac.Sum(nil)
- return fmt.Sprintf("%x", digest)
-}
+ "git.arvados.org/arvados.git/sdk/go/arvados"
+ "git.arvados.org/arvados.git/sdk/go/keepclient"
+)
// SignLocator takes a blobLocator, an apiToken and an expiry time, and
// returns a signed locator string.
-func SignLocator(blobLocator string, apiToken string, expiry time.Time) string {
- // If no permission secret or API token is available,
- // return an unsigned locator.
- if PermissionSecret == nil || apiToken == "" {
- return blobLocator
- }
- // Extract the hash from the blob locator, omitting any size hint that may be present.
- blobHash := strings.Split(blobLocator, "+")[0]
- // Return the signed locator string.
- timestampHex := fmt.Sprintf("%08x", expiry.Unix())
- return blobLocator +
- "+A" + MakePermSignature(blobHash, apiToken, timestampHex) +
- "@" + timestampHex
+func SignLocator(cluster *arvados.Cluster, blobLocator, apiToken string, expiry time.Time) string {
+ return keepclient.SignLocator(blobLocator, apiToken, expiry, cluster.Collections.BlobSigningTTL.Duration(), []byte(cluster.Collections.BlobSigningKey))
}
-var signedLocatorRe = regexp.MustCompile(`^([[:xdigit:]]{32}).*\+A([[:xdigit:]]{40})@([[:xdigit:]]{8})`)
-
// VerifySignature returns nil if the signature on the signedLocator
// can be verified using the given apiToken. Otherwise it returns
// either ExpiredError (if the timestamp has expired, which is
// something the client could have figured out independently) or
// PermissionError.
-func VerifySignature(signedLocator string, apiToken string) error {
- matches := signedLocatorRe.FindStringSubmatch(signedLocator)
- if matches == nil {
- // Could not find a permission signature at all
- return PermissionError
- }
- blobHash := matches[1]
- sigHex := matches[2]
- expHex := matches[3]
- if expTime, err := ParseHexTimestamp(expHex); err != nil {
- return PermissionError
- } else if expTime.Before(time.Now()) {
+func VerifySignature(cluster *arvados.Cluster, signedLocator, apiToken string) error {
+ err := keepclient.VerifySignature(signedLocator, apiToken, cluster.Collections.BlobSigningTTL.Duration(), []byte(cluster.Collections.BlobSigningKey))
+ if err == keepclient.ErrSignatureExpired {
return ExpiredError
- }
- if sigHex != MakePermSignature(blobHash, apiToken, expHex) {
+ } else if err != nil {
return PermissionError
}
return nil
}
-
-// ParseHexTimestamp parses timestamp
-func ParseHexTimestamp(timestampHex string) (ts time.Time, err error) {
- if tsInt, e := strconv.ParseInt(timestampHex, 16, 0); e == nil {
- ts = time.Unix(tsInt, 0)
- } else {
- err = e
- }
- return ts, err
-}
projects / arvados.git / blobdiff