8936: consider blobSigningTtl while generating and verifying signatures.

[arvados.git] / sdk / go / keepclient / perms.go

diff --git a/sdk/go/keepclient/perms.go b/sdk/go/keepclient/perms.go
index a73db76bbbebc8a1c9bedae5df19c54faa4bdb9f..378fdcdff8e8afe2bd7fb53d1e1d6a7f8923106e 100644 (file)
--- a/sdk/go/keepclient/perms.go
+++ b/sdk/go/keepclient/perms.go
@@ -29,13 +29,15 @@ var (
 
 // makePermSignature generates a SHA-1 HMAC digest for the given blob,
 // token, expiry, and site secret.
-func makePermSignature(blobHash, apiToken, expiry string, permissionSecret []byte) string {
+func makePermSignature(blobHash, apiToken, expiry string, blobSigningTTL time.Duration, permissionSecret []byte) 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))
+       hmac.Write([]byte("@"))
+       hmac.Write([]byte(strconv.Itoa(int(blobSigningTTL.Seconds()))))
        digest := hmac.Sum(nil)
        return fmt.Sprintf("%x", digest)
 }
@@ -46,7 +48,7 @@ func makePermSignature(blobHash, apiToken, expiry string, permissionSecret []byt
 //
 // This function is intended to be used by system components and admin
 // utilities: userland programs do not know the permissionSecret.
-func SignLocator(blobLocator, apiToken string, expiry time.Time, permissionSecret []byte) string {
+func SignLocator(blobLocator, apiToken string, expiry time.Time, blobSigningTTL time.Duration, permissionSecret []byte) string {
        if len(permissionSecret) == 0 || apiToken == "" {
                return blobLocator
        }
@@ -54,7 +56,7 @@ func SignLocator(blobLocator, apiToken string, expiry time.Time, permissionSecre
        blobHash := strings.Split(blobLocator, "+")[0]
        timestampHex := fmt.Sprintf("%08x", expiry.Unix())
        return blobLocator +
-               "+A" + makePermSignature(blobHash, apiToken, timestampHex, permissionSecret) +
+               "+A" + makePermSignature(blobHash, apiToken, timestampHex, blobSigningTTL, permissionSecret) +
                "@" + timestampHex
 }
 
@@ -70,20 +72,20 @@ var signedLocatorRe = regexp.MustCompile(`^([[:xdigit:]]{32}).*\+A([[:xdigit:]]{
 //
 // This function is intended to be used by system components and admin
 // utilities: userland programs do not know the permissionSecret.
-func VerifySignature(signedLocator, apiToken string, permissionSecret []byte) error {
+func VerifySignature(signedLocator, apiToken string, blobSigningTTL time.Duration, permissionSecret []byte) error {
        matches := signedLocatorRe.FindStringSubmatch(signedLocator)
        if matches == nil {
                return ErrSignatureMissing
        }
        blobHash := matches[1]
-       sigHex := matches[2]
-       expHex := matches[3]
-       if expTime, err := parseHexTimestamp(expHex); err != nil {
+       signatureHex := matches[2]
+       expiryHex := matches[3]
+       if expiryTime, err := parseHexTimestamp(expiryHex); err != nil {
                return ErrSignatureInvalid
-       } else if expTime.Before(time.Now()) {
+       } else if expiryTime.Before(time.Now()) {
                return ErrSignatureExpired
        }
-       if sigHex != makePermSignature(blobHash, apiToken, expHex, permissionSecret) {
+       if signatureHex != makePermSignature(blobHash, apiToken, expiryHex, blobSigningTTL, permissionSecret) {
                return ErrSignatureInvalid
        }
        return nil