osmo-smdpp: fix generation of transactionId

The hex string of the generated transactionId contains lowercase hex
digits. However SGP.22 explicitly spcifies to use uppercase hex digits
when using JSON fromatted messages. See section 6.5.2.6 for example.

Related: SYS#6720
Change-Id: I8439aa9d70f6fe798fa88b623bac13debdc19ca1
---
M osmo-smdpp.py
1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/osmo-smdpp.py b/osmo-smdpp.py
index 582b222..1f4311d 100755
--- a/osmo-smdpp.py
+++ b/osmo-smdpp.py
@@ -239,7 +239,7 @@
 
         # Generate a TransactionID which is used to identify the ongoing RSP session. The TransactionID
         # SHALL be unique within the scope and lifetime of each SM-DP+.
-        transactionId = uuid.uuid4().hex
+        transactionId = uuid.uuid4().hex.upper()
         assert not transactionId in self.rss
 
         # Generate a serverChallenge for eUICC authentication attached to the ongoing RSP session.

