path: root/taler-nfc-guide.rst
diff options
authorFlorian Dold <>2019-09-13 01:22:53 +0200
committerFlorian Dold <>2019-09-13 01:22:53 +0200
commit26451fd9848a667eae715890815dd083edf5e553 (patch)
tree32a5b2ff7a96b176b78637f75af081bb7d275be3 /taler-nfc-guide.rst
parent0d448e7c2a579f462923e8396beb306e010c6c28 (diff)
nfc clarification
Diffstat (limited to 'taler-nfc-guide.rst')
1 files changed, 2 insertions, 2 deletions
diff --git a/taler-nfc-guide.rst b/taler-nfc-guide.rst
index e610b4c..374dc53 100644
--- a/taler-nfc-guide.rst
+++ b/taler-nfc-guide.rst
@@ -117,9 +117,9 @@ The GNU Taler wallet uses the AID (application identifier) ``F00054414c4552``.
The ``F`` prefix indicates the proprietary/unregistered namespace of AIDs, and
the rest of the identifier is the hex-encoded ASCII-string ``TALER`` (with one 0-byte left padding).
-During the time that wallet is paired with a reader, the communication channel is stateful.
+During the time that the wallet is paired with a reader, there is state associated with the communication channel.
Most importantly, the first message sent by the reader to the wallet must be a ``SELECT FILE (=0xA4)`` that selects
-the GNU Taler AID.
+the GNU Taler AID. Messages that are sent before the correct ``SELECT FILE`` message result in undefined behavior.
The reader sends commands to the wallet with the ``PUT DATA (=0xDA)`` instruction, using the instruction parameters ``0x0100``,
denoting a proprietary instruction.