crypto: improve errors

ErrKeyLock:
	Rename to ErrMlockUlimit for clarity.

ErrGetrandomFail:
ErrKeyAlloc:
ErrKeyFree:
ErrNegativeLength:
	Replace these with one-off unnamed errors because these were all
	returned in only one place and were never checked for.  Also
	these were all either wrapped backwards or discarded an
	underlying error, so fix that too.

1 files changed, 3 insertions, 4 deletions

diff --git a/crypto/rand.go b/crypto/rand.go
index 4d8c044..7d1e55b 100644
--- a/crypto/rand.go
+++ b/crypto/rand.go
@@ -90,10 +90,9 @@ func (r randReader) Read(buffer []byte) (int, error) {
 	case nil:
 		return n, nil
 	case unix.EAGAIN:
-		return 0, errors.Wrap(ErrGetrandomFail, "insufficient entropy in pool")
+		err = errors.New("insufficient entropy in pool")
 	case unix.ENOSYS:
-		return 0, errors.Wrap(ErrGetrandomFail, "kernel must be v3.17 or later")
-	default:
-		return 0, errors.Wrap(ErrGetrandomFail, err.Error())
+		err = errors.New("kernel must be v3.17 or later")
 	}
+	return 0, errors.Wrap(err, "getrandom() failed")
 }