libeufin

commit c8715e29e9777f080c79fb4efd0f5d753a0a19d3
parent 57e371e614689d5a479cc197dffd454b1886e56e
Author: Florian Dold <dold@taler.net>
Date:   Wed,  4 Nov 2026 15:31:35 +0100

nexus: truncate exported IBAN hashes to 128 bits

Diffstat:
M
contrib/export-nexus-withdrawals.sh
 | 
11
++++++-----

1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/contrib/export-nexus-withdrawals.sh b/contrib/export-nexus-withdrawals.sh
@@ -26,9 +26,10 @@ psql uses its usual PGDATABASE, PGHOST, PGUSER, etc. environment variables.
 
 Columns: incoming_transaction_id, execution_time_utc, amount, sender_iban_hash.
 Amounts use the currency configured for this Nexus instance (not stored in SQL).
-The hash is SHA-256(random 32-byte salt || uppercase IBAN). One fresh salt is
-used for the entire export, so senders can be grouped within a file but hashes
-change between runs. The salt is not included in the CSV or saved by the script.
+The hash is SHA-256(random 32-byte salt || uppercase IBAN), truncated to
+128 bits (32 hexadecimal characters). One fresh salt is used for the entire
+export, so senders can be grouped within a file but hashes change between runs.
+The salt is not included in the CSV or saved by the script.
 Names, payment subjects, and raw payto URIs are not exported.
 Unsupported/missing IBANs cause an error instead of silently dropping transfers.
 The output file is replaced only after a successful export, with mode 0600.
@@ -104,10 +105,10 @@ COPY (
                'YYYY-MM-DD"T"HH24:MI:SS.US"Z"'
            ) AS execution_time_utc,
            (i.amount).val::text || '.' || lpad((i.amount).frac::text, 8, '0') AS amount,
-           encode(sha256(
+           left(encode(sha256(
                decode(:'export_salt', 'hex')
                || convert_to(upper(substring(i.debit_payto FROM ('(?i)' || :'iban_pattern'))), 'UTF8')
-           ), 'hex') AS sender_iban_hash
+           ), 'hex'), 32) AS sender_iban_hash
     FROM libeufin_nexus.incoming_transactions AS i
     JOIN libeufin_nexus.talerable_incoming_transactions AS t
       USING (incoming_transaction_id)