From: Arne Schwabe <arne@rfc2549.org>
Date: Sat, 21 Dec 2024 22:39:05 +0000 (+0100)
Subject: Split init_key_ctx_bi into send/recv init
X-Git-Tag: v2.7_alpha1~145
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=435cc9a7535c86c1ab513ae106895960c183095e;p=thirdparty%2Fopenvpn.git

Split init_key_ctx_bi into send/recv init

This allows for only initialising one of the keys. This is needed
for epoch keys where key rotation of send/recv key can happen at
different time points.

Change-Id: If9e029bdac264dcc05b2d256c4d323315904a92b
Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20241221223905.18820-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg30151.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
---

diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
index faf69fc3..982fb017 100644
--- a/src/openvpn/crypto.c
+++ b/src/openvpn/crypto.c
@@ -938,8 +938,8 @@ init_key_ctx(struct key_ctx *ctx, const struct key *key,
 }
 
 void
-init_key_ctx_bi(struct key_ctx_bi *ctx, const struct key2 *key2,
-                int key_direction, const struct key_type *kt, const char *name)
+init_key_bi_ctx_send(struct key_ctx *ctx, const struct key2 *key2,
+                     int key_direction, const struct key_type *kt, const char *name)
 {
     char log_prefix[128] = { 0 };
     struct key_direction_state kds;
@@ -947,13 +947,32 @@ init_key_ctx_bi(struct key_ctx_bi *ctx, const struct key2 *key2,
     key_direction_state_init(&kds, key_direction);
 
     snprintf(log_prefix, sizeof(log_prefix), "Outgoing %s", name);
-    init_key_ctx(&ctx->encrypt, &key2->keys[kds.out_key], kt,
+    init_key_ctx(ctx, &key2->keys[kds.out_key], kt,
                  OPENVPN_OP_ENCRYPT, log_prefix);
 
+}
+
+void
+init_key_bi_ctx_recv(struct key_ctx *ctx, const struct key2 *key2,
+                     int key_direction, const struct key_type *kt, const char *name)
+{
+    char log_prefix[128] = { 0 };
+    struct key_direction_state kds;
+
+    key_direction_state_init(&kds, key_direction);
+
     snprintf(log_prefix, sizeof(log_prefix), "Incoming %s", name);
-    init_key_ctx(&ctx->decrypt, &key2->keys[kds.in_key], kt,
+    init_key_ctx(ctx, &key2->keys[kds.in_key], kt,
                  OPENVPN_OP_DECRYPT, log_prefix);
 
+}
+
+void
+init_key_ctx_bi(struct key_ctx_bi *ctx, const struct key2 *key2,
+                int key_direction, const struct key_type *kt, const char *name)
+{
+    init_key_bi_ctx_send(&ctx->encrypt, key2, key_direction, kt, name);
+    init_key_bi_ctx_recv(&ctx->decrypt, key2, key_direction, kt, name);
     ctx->initialized = true;
 }
 
@@ -971,6 +990,8 @@ free_key_ctx(struct key_ctx *ctx)
         hmac_ctx_free(ctx->hmac);
         ctx->hmac = NULL;
     }
+    CLEAR(ctx->implicit_iv);
+    ctx->plaintext_blocks = 0;
 }
 
 void
diff --git a/src/openvpn/crypto.h b/src/openvpn/crypto.h
index 4579b658..b3612fbf 100644
--- a/src/openvpn/crypto.h
+++ b/src/openvpn/crypto.h
@@ -196,7 +196,9 @@ struct key2
     int n;                      /**< The number of \c key objects stored
                                  *   in the \c key2.keys array. */
     struct key keys[2];         /**< Two unidirectional sets of %key
-                                 *   material. */
+                                 *   material. The first key is the client
+                                 *   (encrypts) to server (decrypts), the
+                                 *   second the server to client key. */
 };
 
 /**
@@ -349,6 +351,16 @@ void init_key_ctx(struct key_ctx *ctx, const struct key *key,
                   const struct key_type *kt, int enc,
                   const char *prefix);
 
+void
+init_key_bi_ctx_send(struct key_ctx *ctx, const struct key2 *key2,
+                     int key_direction, const struct key_type *kt,
+                     const char *name);
+
+void
+init_key_bi_ctx_recv(struct key_ctx *ctx, const struct key2 *key2,
+                     int key_direction, const struct key_type *kt,
+                     const char *name);
+
 void free_key_ctx(struct key_ctx *ctx);
 
 void init_key_ctx_bi(struct key_ctx_bi *ctx, const struct key2 *key2,