From 818d68126da6680228cbae1fdd88e126647dbd52 Mon Sep 17 00:00:00 2001
From: Johannes Roth <johannes.roth@mtg.de>
Date: Tue, 25 Apr 2023 16:49:07 +0200
Subject: [PATCH] rework some AEAD/SEIPDv2 logic, address issue #21

---
 src/lib/rnp.cpp               |  8 +++++++-
 src/librepgp/stream-write.cpp | 13 ++++++-------
 src/tests/ffi-enc.cpp         |  9 ++++++++-
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/lib/rnp.cpp b/src/lib/rnp.cpp
index e06495b6..d4dc75be 100644
--- a/src/lib/rnp.cpp
+++ b/src/lib/rnp.cpp
@@ -2743,6 +2743,11 @@ try {
         FFI_LOG(op->ffi, "Invalid AEAD algorithm: %s", alg);
         return RNP_ERROR_BAD_PARAMETERS;
     }
+
+    if(op->rnpctx.aalg == PGP_AEAD_NONE && op->rnpctx.enable_pkesk_v6) {
+        FFI_LOG(op->ffi, "Setting AEAD algorithm to PGP_AEAD_NONE (%s) would contradict the previously enabled PKESKv6 setting", alg);
+        return RNP_ERROR_BAD_PARAMETERS;
+    }
     return RNP_SUCCESS;
 }
 FFI_GUARD
@@ -2851,7 +2856,8 @@ try {
     // set the default hash alg if none was specified
     if (!op->rnpctx.halg) {
         op->rnpctx.halg = DEFAULT_PGP_HASH_ALG;
-        }
+    }
+
     pgp_write_handler_t handler =
       pgp_write_handler(&op->ffi->pass_provider, &op->rnpctx, NULL, &op->ffi->key_provider);
 
diff --git a/src/librepgp/stream-write.cpp b/src/librepgp/stream-write.cpp
index 23064850..409cc142 100644
--- a/src/librepgp/stream-write.cpp
+++ b/src/librepgp/stream-write.cpp
@@ -1086,14 +1086,13 @@ init_encrypted_dst(pgp_write_handler_t *handler, pgp_dest_t *dst, pgp_dest_t *wr
     for (auto recipient : handler->ctx->recipients) {
         pgp_pkesk_version_t pkesk_version = PGP_PKSK_V3;
 #if defined(ENABLE_CRYPTO_REFRESH)
-        if (handler->ctx->enable_pkesk_v6 && handler->ctx->pkeskv6_capable()) {
+        if (param->auth_type == rnp::AuthType::AEADv2) {
             pkesk_version = PGP_PKSK_V6;
-            param->auth_type = rnp::AuthType::AEADv2;
-            if(param->ctx->aalg == PGP_AEAD_NONE)
-            {
-                param->ctx->aalg = PGP_AEAD_OCB; // TODO-V6: is this the right place to set the default algorithm? 
-            }
-            dst->write = encrypted_dst_write_aead; // currently necessary 
+        }
+        if(handler->ctx->aalg == PGP_AEAD_NONE) {
+            // set default AEAD if not set
+            // TODO-V6: is this the right place to set the default algorithm?
+            param->aalg = DEFAULT_AEAD_ALG;
         }
 #endif
         ret = encrypted_add_recipient(
diff --git a/src/tests/ffi-enc.cpp b/src/tests/ffi-enc.cpp
index c40ec288..b5e081c4 100644
--- a/src/tests/ffi-enc.cpp
+++ b/src/tests/ffi-enc.cpp
@@ -787,8 +787,15 @@ TEST_F(rnp_tests, test_ffi_encrypt_pk_with_v6_key)
         key = NULL;
 
         // set the data encryption cipher
-        assert_rnp_success(rnp_op_encrypt_set_aead(op, aead.c_str()));
+        if((aead == "None") && enable_pkeskv6) {
+            // already enabled v6 pkesk, does not make any sense to set AEAD to None explicitly.
+            assert_rnp_failure(rnp_op_encrypt_set_aead(op, aead.c_str()));
+        }
+        else {
+            assert_rnp_success(rnp_op_encrypt_set_aead(op, aead.c_str()));
+        }
         assert_rnp_success(rnp_op_encrypt_set_cipher(op, cipher.c_str()));
+
         // execute the operation
         assert_rnp_success(rnp_op_encrypt_execute(op));