[Openvpn-devel,S] Change in openvpn[master]: Split init_key_ctx_bi into send/recv init

Message ID a93ba4ed256c4d8ac55d3798af9643bda876d23f-HTML@gerrit.openvpn.net
State New
Headers show
Series [Openvpn-devel,S] Change in openvpn[master]: Split init_key_ctx_bi into send/recv init | expand

Commit Message

flichtenheld (Code Review) Nov. 11, 2024, 1:59 a.m. UTC
Attention is currently required from: flichtenheld.

Hello flichtenheld,

I'd like you to do a code review.
Please visit

    http://gerrit.openvpn.net/c/openvpn/+/799?usp=email

to review the following change.


Change subject: Split init_key_ctx_bi into send/recv init
......................................................................

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>
---
M src/openvpn/crypto.c
M src/openvpn/crypto.h
2 files changed, 38 insertions(+), 5 deletions(-)



  git pull ssh://gerrit.openvpn.net:29418/openvpn refs/changes/99/799/1

Patch

diff --git a/src/openvpn/crypto.c b/src/openvpn/crypto.c
index a366474..f0b60a3 100644
--- a/src/openvpn/crypto.c
+++ b/src/openvpn/crypto.c
@@ -939,8 +939,8 @@ 
 }
 
 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;
@@ -948,13 +948,32 @@ 
     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;
 }
 
@@ -972,6 +991,8 @@ 
         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 0ae86f4..3331672 100644
--- a/src/openvpn/crypto.h
+++ b/src/openvpn/crypto.h
@@ -189,7 +189,9 @@ 
     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. */
 };
 
 /**
@@ -342,6 +344,16 @@ 
                   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,