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, 5 insertions, 5 deletions

diff --git a/crypto/key.go b/crypto/key.go
index 77adc95..2e57443 100644
--- a/crypto/key.go
+++ b/crypto/key.go
@@ -98,7 +98,7 @@ func NewBlankKey(length int) (*Key, error) {
 	if length == 0 {
 		return &Key{data: nil}, nil
 	} else if length < 0 {
-		return nil, errors.Wrapf(ErrNegativeLength, "length of %d requested", length)
+		return nil, errors.Errorf("requested key length %d is negative", length)
 	}
 
 	flags := keyMmapFlags
@@ -109,11 +109,11 @@ func NewBlankKey(length int) (*Key, error) {
 	// See MAP_ANONYMOUS in http://man7.org/linux/man-pages/man2/mmap.2.html
 	data, err := unix.Mmap(-1, 0, length, keyProtection, flags)
 	if err == unix.EAGAIN {
-		return nil, ErrKeyLock
+		return nil, ErrMlockUlimit
 	}
 	if err != nil {
-		log.Printf("unix.Mmap() with length=%d failed: %v", length, err)
-		return nil, ErrKeyAlloc
+		return nil, errors.Wrapf(err,
+			"failed to allocate (mmap) key buffer of length %d", length)
 	}
 
 	key := &Key{data: data}
@@ -139,7 +139,7 @@ func (key *Key) Wipe() error {
 
 		if err := unix.Munmap(data); err != nil {
 			log.Printf("unix.Munmap() failed: %v", err)
-			return ErrKeyFree
+			return errors.Wrapf(err, "failed to free (munmap) key buffer")
 		}
 	}
 	return nil