5562: Use static method. Fixes "TypeError: _socket_open() takes exactly 5 arguments...

[arvados.git] / services / keepstore / perms.go

diff --git a/services/keepstore/perms.go b/services/keepstore/perms.go
index 143815576b33f077a89fead6e46efb795de20f9d..1048f53130315525da0a80c1214207a9eb101cd5 100644 (file)
--- a/services/keepstore/perms.go
+++ b/services/keepstore/perms.go
@@ -80,23 +80,24 @@ func SignLocator(blob_locator string, api_token string, expiry time.Time) string
                "@" + timestamp_hex
 }
 
+var signedLocatorRe = regexp.MustCompile(`^([[:xdigit:]]{32}).*\+A([[:xdigit:]]{40})@([[:xdigit:]]{8})`)
+
 // VerifySignature returns true if the signature on the signed_locator
 // can be verified using the given api_token.
 func VerifySignature(signed_locator string, api_token string) bool {
-       if re, err := regexp.Compile(`^([a-f0-9]{32}(\+[0-9]+)?).*\+A[[:xdigit:]]+@([[:xdigit:]]{8})`); err == nil {
-               if matches := re.FindStringSubmatch(signed_locator); matches != nil {
-                       blob_locator := matches[1]
-                       timestamp_hex := matches[3]
-                       if expire_ts, err := ParseHexTimestamp(timestamp_hex); err == nil {
-                               // Fail signatures with expired timestamps.
-                               if expire_ts.Before(time.Now()) {
-                                       return false
-                               }
-                               return signed_locator == SignLocator(blob_locator, api_token, expire_ts)
-                       }
-               }
+       matches := signedLocatorRe.FindStringSubmatch(signed_locator)
+       if matches == nil {
+               // Could not find a permission signature at all
+               return false
+       }
+       blob_hash := matches[1]
+       sig_hex := matches[2]
+       exp_hex := matches[3]
+       if exp_time, err := ParseHexTimestamp(exp_hex); err != nil || exp_time.Before(time.Now()) {
+               // Signature is expired, or timestamp is unparseable
+               return false
        }
-       return false
+       return sig_hex == MakePermSignature(blob_hash, api_token, exp_hex)
 }
 
 func ParseHexTimestamp(timestamp_hex string) (ts time.Time, err error) {