Merge pull request #383 from h2o/kazuho/offload
add API to obtain traffic keys for offloading
diff --git a/include/picotls.h b/include/picotls.h
index a17b917..ae4f7b9 100644
--- a/include/picotls.h
+++ b/include/picotls.h
@@ -1153,6 +1153,12 @@
*/
ptls_cipher_suite_t *ptls_get_cipher(ptls_t *tls);
/**
+ * Returns current state of traffic keys. The cipher-suite being used, as well as the length of the traffic keys, can be obtained
+ * via `ptls_get_cipher`.
+ * TODO: Even in case of offloading just the TX side, there should be API for handling key updates, sending Close aleart.
+ */
+int ptls_get_traffic_keys(ptls_t *tls, int is_enc, uint8_t *key, uint8_t *iv, uint64_t *seq);
+/**
* returns the server-name (NULL if SNI is not used or failed to negotiate)
*/
const char *ptls_get_server_name(ptls_t *tls);
diff --git a/lib/picotls.c b/lib/picotls.c
index 90b013b..8bb5b13 100644
--- a/lib/picotls.c
+++ b/lib/picotls.c
@@ -1192,6 +1192,20 @@
label_prefix);
}
+static int get_traffic_keys(ptls_aead_algorithm_t *aead, ptls_hash_algorithm_t *hash, void *key, void *iv, const void *secret,
+ ptls_iovec_t hash_value, const char *label_prefix)
+{
+ int ret;
+
+ if ((ret = get_traffic_key(hash, key, aead->key_size, 0, secret, hash_value, label_prefix)) != 0 ||
+ (ret = get_traffic_key(hash, iv, aead->iv_size, 1, secret, hash_value, label_prefix)) != 0) {
+ ptls_clear_memory(key, aead->key_size);
+ ptls_clear_memory(iv, aead->iv_size);
+ }
+
+ return ret;
+}
+
static int setup_traffic_protection(ptls_t *tls, int is_enc, const char *secret_label, size_t epoch, int skip_notify)
{
static const char *log_labels[2][4] = {
@@ -4422,6 +4436,18 @@
return tls->cipher_suite;
}
+int ptls_get_traffic_keys(ptls_t *tls, int is_enc, uint8_t *key, uint8_t *iv, uint64_t *seq)
+{
+ struct st_ptls_traffic_protection_t *ctx = is_enc ? &tls->traffic_protection.enc : &tls->traffic_protection.dec;
+ int ret;
+
+ if ((ret = get_traffic_keys(tls->cipher_suite->aead, tls->cipher_suite->hash, key, iv, ctx->secret, ptls_iovec_init(NULL, 0),
+ NULL)) != 0)
+ return ret;
+ *seq = ctx->seq;
+ return 0;
+}
+
const char *ptls_get_server_name(ptls_t *tls)
{
return tls->server_name;
@@ -5215,17 +5241,18 @@
ptls_iovec_t hash_value, const char *label_prefix)
{
ptls_aead_context_t *ctx = NULL;
- uint8_t key_iv[PTLS_MAX_SECRET_SIZE + PTLS_MAX_IV_SIZE];
+ struct {
+ uint8_t key[PTLS_MAX_SECRET_SIZE];
+ uint8_t iv[PTLS_MAX_IV_SIZE];
+ } key_iv;
int ret;
- if ((ret = get_traffic_key(hash, key_iv, aead->key_size, 0, secret, hash_value, label_prefix)) != 0)
+ if ((ret = get_traffic_keys(aead, hash, key_iv.key, key_iv.iv, secret, hash_value, label_prefix)) != 0)
goto Exit;
- if ((ret = get_traffic_key(hash, key_iv + aead->key_size, aead->iv_size, 1, secret, hash_value, label_prefix)) != 0)
- goto Exit;
- ctx = ptls_aead_new_direct(aead, is_enc, key_iv, key_iv + aead->key_size);
+ ctx = ptls_aead_new_direct(aead, is_enc, key_iv.key, key_iv.iv);
Exit:
- ptls_clear_memory(key_iv, sizeof(key_iv));
+ ptls_clear_memory(&key_iv, sizeof(key_iv));
return ctx;
}
