Merge pull request #443 from h2o/kazuho/newextmap
use the same table as RFC 8446 section 4.2
diff --git a/include/picotls.h b/include/picotls.h
index 2d3c096..29f12cb 100644
--- a/include/picotls.h
+++ b/include/picotls.h
@@ -265,6 +265,7 @@
#define PTLS_HANDSHAKE_TYPE_KEY_UPDATE 24
#define PTLS_HANDSHAKE_TYPE_COMPRESSED_CERTIFICATE 25
#define PTLS_HANDSHAKE_TYPE_MESSAGE_HASH 254
+#define PTLS_HANDSHAKE_TYPE_PSEUDO_HRR -1
#define PTLS_CERTIFICATE_TYPE_X509 0
#define PTLS_CERTIFICATE_TYPE_RAW_PUBLIC_KEY 2
diff --git a/lib/picotls.c b/lib/picotls.c
index 1c747b4..34058ec 100644
--- a/lib/picotls.c
+++ b/lib/picotls.c
@@ -403,73 +403,51 @@
bitmap->bits[id / 8] |= 1 << (id % 8);
}
-static inline void init_extension_bitmap(struct st_ptls_extension_bitmap_t *bitmap, uint8_t hstype)
+static inline void init_extension_bitmap(struct st_ptls_extension_bitmap_t *bitmap, unsigned hstype)
{
- *bitmap = (struct st_ptls_extension_bitmap_t){{0}};
-
-#define EXT(extid, proc) \
+#define HSTYPE_TO_BIT(hstype) ((uint64_t)1 << ((hstype) + 1)) /* min(hstype) is -1 (PSEUDO_HRR) */
+#define DEFINE_BIT(abbrev, hstype) static const uint64_t abbrev = HSTYPE_TO_BIT(PTLS_HANDSHAKE_TYPE_##hstype)
+#define EXT(extid, allowed_bits) \
do { \
- int _found = 0; \
- do { \
- proc \
- } while (0); \
- if (!_found) \
+ if (((allowed_bits)&HSTYPE_TO_BIT(hstype)) == 0) \
extension_bitmap_set(bitmap, PTLS_EXTENSION_TYPE_##extid); \
} while (0)
-#define ALLOW(allowed_hstype) _found = _found || hstype == PTLS_HANDSHAKE_TYPE_##allowed_hstype
- /* Implements the table found in section 4.2 of draft-19; "If an implementation receives an extension which it recognizes and
- * which is not specified for the message in which it appears it MUST abort the handshake with an “illegal_parameter” alert."
- */
- EXT(SERVER_NAME, {
- ALLOW(CLIENT_HELLO);
- ALLOW(ENCRYPTED_EXTENSIONS);
- });
- EXT(STATUS_REQUEST, {
- ALLOW(CLIENT_HELLO);
- ALLOW(CERTIFICATE);
- ALLOW(CERTIFICATE_REQUEST);
- });
- EXT(SUPPORTED_GROUPS, {
- ALLOW(CLIENT_HELLO);
- ALLOW(ENCRYPTED_EXTENSIONS);
- });
- EXT(SIGNATURE_ALGORITHMS, {
- ALLOW(CLIENT_HELLO);
- ALLOW(CERTIFICATE_REQUEST);
- });
- EXT(ALPN, {
- ALLOW(CLIENT_HELLO);
- ALLOW(ENCRYPTED_EXTENSIONS);
- });
- EXT(KEY_SHARE, {
- ALLOW(CLIENT_HELLO);
- ALLOW(SERVER_HELLO);
- });
- EXT(PRE_SHARED_KEY, {
- ALLOW(CLIENT_HELLO);
- ALLOW(SERVER_HELLO);
- });
- EXT(PSK_KEY_EXCHANGE_MODES, { ALLOW(CLIENT_HELLO); });
- EXT(EARLY_DATA, {
- ALLOW(CLIENT_HELLO);
- ALLOW(ENCRYPTED_EXTENSIONS);
- ALLOW(NEW_SESSION_TICKET);
- });
- EXT(COOKIE, {
- ALLOW(CLIENT_HELLO);
- ALLOW(SERVER_HELLO);
- });
- EXT(SUPPORTED_VERSIONS, {
- ALLOW(CLIENT_HELLO);
- ALLOW(SERVER_HELLO);
- });
- EXT(SERVER_CERTIFICATE_TYPE, {
- ALLOW(CLIENT_HELLO);
- ALLOW(ENCRYPTED_EXTENSIONS);
- });
+ DEFINE_BIT(CH, CLIENT_HELLO);
+ DEFINE_BIT(SH, SERVER_HELLO);
+ DEFINE_BIT(HRR, PSEUDO_HRR);
+ DEFINE_BIT(EE, ENCRYPTED_EXTENSIONS);
+ DEFINE_BIT(CR, CERTIFICATE_REQUEST);
+ DEFINE_BIT(CT, CERTIFICATE);
+ DEFINE_BIT(NST, NEW_SESSION_TICKET);
-#undef ALLOW
+ *bitmap = (struct st_ptls_extension_bitmap_t){{0}};
+
+ /* clang-format off */
+ /* RFC 8446 section 4.2: "The table below indicates the messages where a given extension may appear... If an implementation
+ * receives an extension which it recognizes and which is not specified for the message in which it appears, it MUST abort the
+ * handshake with an "illegal_parameter" alert.
+ *
+ * +-------------------------+---------------+
+ * + Extension | Allowed |
+ * +-------------------------+---------------+ */
+ EXT( SERVER_NAME , CH + EE );
+ EXT( STATUS_REQUEST , CH + CR + CT );
+ EXT( SUPPORTED_GROUPS , CH + EE );
+ EXT( SIGNATURE_ALGORITHMS , CH + CR );
+ EXT( ALPN , CH + EE );
+ EXT( SERVER_CERTIFICATE_TYPE , CH + EE );
+ EXT( KEY_SHARE , CH + SH + HRR );
+ EXT( PRE_SHARED_KEY , CH + SH );
+ EXT( PSK_KEY_EXCHANGE_MODES , CH );
+ EXT( EARLY_DATA , CH + EE + NST );
+ EXT( COOKIE , CH + HRR );
+ EXT( SUPPORTED_VERSIONS , CH + SH + HRR );
+ /* +-----------------------------------------+ */
+ /* clang-format on */
+
+#undef HSTYPE_TO_BIT
+#undef DEFINE_ABBREV
#undef EXT
}
@@ -2310,63 +2288,56 @@
sh->retry_request.selected_group = UINT16_MAX;
uint16_t exttype, found_version = UINT16_MAX, selected_psk_identity = UINT16_MAX;
- decode_extensions(src, end, PTLS_HANDSHAKE_TYPE_SERVER_HELLO, &exttype, {
- if (tls->ctx->on_extension != NULL &&
- (ret = tls->ctx->on_extension->cb(tls->ctx->on_extension, tls, PTLS_HANDSHAKE_TYPE_SERVER_HELLO, exttype,
- ptls_iovec_init(src, end - src)) != 0))
- goto Exit;
- switch (exttype) {
- case PTLS_EXTENSION_TYPE_SUPPORTED_VERSIONS:
- if ((ret = ptls_decode16(&found_version, &src, end)) != 0)
- goto Exit;
- break;
- case PTLS_EXTENSION_TYPE_KEY_SHARE:
- if (sh->is_retry_request) {
- if ((ret = ptls_decode16(&sh->retry_request.selected_group, &src, end)) != 0)
- goto Exit;
- } else {
- uint16_t group;
- if ((ret = decode_key_share_entry(&group, &sh->peerkey, &src, end)) != 0)
- goto Exit;
- if (src != end) {
- ret = PTLS_ALERT_DECODE_ERROR;
- goto Exit;
- }
- if (tls->key_share == NULL || tls->key_share->id != group) {
- ret = PTLS_ALERT_ILLEGAL_PARAMETER;
- goto Exit;
- }
- }
- break;
- case PTLS_EXTENSION_TYPE_COOKIE:
- if (sh->is_retry_request) {
- ptls_decode_block(src, end, 2, {
- if (src == end) {
- ret = PTLS_ALERT_DECODE_ERROR;
- goto Exit;
- }
- sh->retry_request.cookie = ptls_iovec_init(src, end - src);
- src = end;
- });
- } else {
- ret = PTLS_ALERT_ILLEGAL_PARAMETER;
- goto Exit;
- }
- break;
- case PTLS_EXTENSION_TYPE_PRE_SHARED_KEY:
- if (sh->is_retry_request) {
- ret = PTLS_ALERT_ILLEGAL_PARAMETER;
- goto Exit;
- } else {
- if ((ret = ptls_decode16(&selected_psk_identity, &src, end)) != 0)
- goto Exit;
- }
- break;
- default:
- src = end;
- break;
- }
- });
+ decode_extensions(src, end, sh->is_retry_request ? PTLS_HANDSHAKE_TYPE_PSEUDO_HRR : PTLS_HANDSHAKE_TYPE_SERVER_HELLO, &exttype,
+ {
+ if (tls->ctx->on_extension != NULL &&
+ (ret = tls->ctx->on_extension->cb(tls->ctx->on_extension, tls, PTLS_HANDSHAKE_TYPE_SERVER_HELLO,
+ exttype, ptls_iovec_init(src, end - src)) != 0))
+ goto Exit;
+ switch (exttype) {
+ case PTLS_EXTENSION_TYPE_SUPPORTED_VERSIONS:
+ if ((ret = ptls_decode16(&found_version, &src, end)) != 0)
+ goto Exit;
+ break;
+ case PTLS_EXTENSION_TYPE_KEY_SHARE:
+ if (sh->is_retry_request) {
+ if ((ret = ptls_decode16(&sh->retry_request.selected_group, &src, end)) != 0)
+ goto Exit;
+ } else {
+ uint16_t group;
+ if ((ret = decode_key_share_entry(&group, &sh->peerkey, &src, end)) != 0)
+ goto Exit;
+ if (src != end) {
+ ret = PTLS_ALERT_DECODE_ERROR;
+ goto Exit;
+ }
+ if (tls->key_share == NULL || tls->key_share->id != group) {
+ ret = PTLS_ALERT_ILLEGAL_PARAMETER;
+ goto Exit;
+ }
+ }
+ break;
+ case PTLS_EXTENSION_TYPE_COOKIE:
+ assert(sh->is_retry_request);
+ ptls_decode_block(src, end, 2, {
+ if (src == end) {
+ ret = PTLS_ALERT_DECODE_ERROR;
+ goto Exit;
+ }
+ sh->retry_request.cookie = ptls_iovec_init(src, end - src);
+ src = end;
+ });
+ break;
+ case PTLS_EXTENSION_TYPE_PRE_SHARED_KEY:
+ assert(!sh->is_retry_request);
+ if ((ret = ptls_decode16(&selected_psk_identity, &src, end)) != 0)
+ goto Exit;
+ break;
+ default:
+ src = end;
+ break;
+ }
+ });
if (!is_supported_version(found_version)) {
ret = PTLS_ALERT_ILLEGAL_PARAMETER;
