Document password callback.

git-svn-id: https://cryptsetup.googlecode.com/svn/trunk@412 36d66b0a-2a48-0410-832c-cd162a569da5

diff --git a/lib/libcryptsetup.h b/lib/libcryptsetup.h
index abedba2..872dd1d 100644 (file)
--- a/lib/libcryptsetup.h
+++ b/lib/libcryptsetup.h
@@ -85,6 +85,9 @@ void crypt_set_confirm_callback(struct crypt_device *cd,
  * @buf - buffer for password
  * @length - size of buffer
  *
+ * Calback should return length of password in buffer
+ * or negative errno value in case of error.
+ *
  * - Note that if this function is defined, verify option is ignored
  *   (caller which provided callback is responsible for password verification)
  * - Only zero terminated passwords can be entered this way, for complex