postgres_fdw: improve security checks SCRAM pass-through should not bypass the FDW security check as it was implemented for postgres_fdw in commit 761c79508e7.
This commit improves the security check by adding new SCRAM pass-through checks to ensure that the required SCRAM connection options are not overwritten by the user mapping or foreign server options. This is meant to match the security requirements for a password-using connection. Since libpq has no SCRAM-specific equivalent of PQconnectionUsedPassword(), we enforce this instead by making the use_scram_passthrough option of postgres_fdw imply require_auth=scram-sha-256. This means that if use_scram_passthrough is set, some situations that might otherwise have worked are preempted, for example GSSAPI with delegated credentials. This could be enhanced in the future if there is desire for more flexibility. Reported-by: Jacob Champion <jacob.champ...@enterprisedb.com> Author: Matheus Alcantara <mths....@pm.me> Co-authored-by: Jacob Champion <jacob.champ...@enterprisedb.com> Reviewed-by: Jacob Champion <jacob.champ...@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/flat/CAFY6G8ercA1KES%3DE_0__R9QCTR805TTyYr1No8qF8ZxmMg8z2Q%40mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/76563f88cfbd91696e7ebe568dead648f2d229ff Modified Files -------------- contrib/postgres_fdw/connection.c | 102 ++++++++++++++++++++++++++----- contrib/postgres_fdw/t/001_auth_scram.pl | 41 +++++++++++++ doc/src/sgml/postgres-fdw.sgml | 11 +--- 3 files changed, 132 insertions(+), 22 deletions(-)
