ipa/SOURCES/0019-Vault-add-support-for-RSA-OAEP-wrapping-algo.patch

From 163f06cab678d517ab30ab6da59ae339f39ee7cf Mon Sep 17 00:00:00 2001
From: Francisco Trivino <ftrivino@redhat.com>
Date: Fri, 27 May 2022 17:31:40 +0200
Subject: [PATCH] Vault: add support for RSA-OAEP wrapping algo

None of the FIPS certified modules in RHEL support PKCS#1 v1.5 as FIPS
approved mechanism. This commit adds support for RSA-OAEP padding as a
fallback.

Fixes: https://pagure.io/freeipa/issue/9191

Signed-off-by: Francisco Trivino <ftrivino@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
(cherry picked from commit b1fb31fd20c900c9ff1d5d28dfe136439f6bf605)
---
 ipaclient/plugins/vault.py | 57 ++++++++++++++++++++++++++++++--------
 1 file changed, 45 insertions(+), 12 deletions(-)

diff --git a/ipaclient/plugins/vault.py b/ipaclient/plugins/vault.py
index d4c84eb6b..ed16c73ae 100644
--- a/ipaclient/plugins/vault.py
+++ b/ipaclient/plugins/vault.py
@@ -119,8 +119,8 @@ def encrypt(data, symmetric_key=None, public_key=None):
         return public_key_obj.encrypt(
             data,
             padding.OAEP(
-                mgf=padding.MGF1(algorithm=hashes.SHA1()),
-                algorithm=hashes.SHA1(),
+                mgf=padding.MGF1(algorithm=hashes.SHA256()),
+                algorithm=hashes.SHA256(),
                 label=None
             )
         )
@@ -154,8 +154,8 @@ def decrypt(data, symmetric_key=None, private_key=None):
             return private_key_obj.decrypt(
                 data,
                 padding.OAEP(
-                    mgf=padding.MGF1(algorithm=hashes.SHA1()),
-                    algorithm=hashes.SHA1(),
+                    mgf=padding.MGF1(algorithm=hashes.SHA256()),
+                    algorithm=hashes.SHA256(),
                     label=None
                 )
             )
@@ -705,14 +705,39 @@ class ModVaultData(Local):
         return transport_cert, wrapping_algo
 
     def _do_internal(self, algo, transport_cert, raise_unexpected,
-                     *args, **options):
+                     use_oaep=False, *args, **options):
         public_key = transport_cert.public_key()
 
         # wrap session key with transport certificate
-        wrapped_session_key = public_key.encrypt(
-            algo.key,
-            padding.PKCS1v15()
-        )
+        # KRA may be configured using either the default PKCS1v15 or RSA-OAEP.
+        # there is no way to query this info using the REST interface.
+        if not use_oaep:
+            # PKCS1v15() causes an OpenSSL exception when FIPS is enabled
+            # if so, we fallback to RSA-OAEP
+            try:
+                wrapped_session_key = public_key.encrypt(
+                    algo.key,
+                    padding.PKCS1v15()
+                )
+            except ValueError:
+                wrapped_session_key = public_key.encrypt(
+                    algo.key,
+                    padding.OAEP(
+                        mgf=padding.MGF1(algorithm=hashes.SHA256()),
+                        algorithm=hashes.SHA256(),
+                        label=None
+                    )
+                )
+        else:
+            wrapped_session_key = public_key.encrypt(
+                algo.key,
+                padding.OAEP(
+                    mgf=padding.MGF1(algorithm=hashes.SHA256()),
+                    algorithm=hashes.SHA256(),
+                    label=None
+                )
+            )
+
         options['session_key'] = wrapped_session_key
 
         name = self.name + '_internal'
@@ -723,7 +748,7 @@ class ModVaultData(Local):
                 errors.ExecutionError,
                 errors.GenericError):
             _kra_config_cache.remove(self.api.env.domain)
-            if raise_unexpected:
+            if raise_unexpected and use_oaep:
                 raise
         return None
 
@@ -733,15 +758,23 @@ class ModVaultData(Local):
         """
         # try call with cached transport certificate
         result = self._do_internal(algo, transport_cert, False,
-                                       *args, **options)
+                                   False, *args, **options)
         if result is not None:
             return result
 
         # retrieve transport certificate (cached by vaultconfig_show)
         transport_cert = self._get_vaultconfig(force_refresh=True)[0]
+
         # call with the retrieved transport certificate
+        result = self._do_internal(algo, transport_cert, True,
+                                   False, *args, **options)
+
+        if result is not None:
+            return result
+
+        # call and use_oaep this time, last attempt
         return self._do_internal(algo, transport_cert, True,
-                                 *args, **options)
+                                 True, *args, **options)
 
 
 @register(no_fail=True)
-- 
2.43.0