Restoring authorship annotation for <deshevoy@yandex-team.ru>. Commit 1 of 2.

1 files changed, 531 insertions, 531 deletions

diff --git a/contrib/libs/openssl/ssl/statem/extensions_cust.c b/contrib/libs/openssl/ssl/statem/extensions_cust.c
index a0ba18efa7..e76b2e6a48 100644
--- a/contrib/libs/openssl/ssl/statem/extensions_cust.c
+++ b/contrib/libs/openssl/ssl/statem/extensions_cust.c
@@ -1,533 +1,533 @@
-/*
- * Copyright 2014-2018 The OpenSSL Project Authors. All Rights Reserved.
- *
- * Licensed under the OpenSSL license (the "License").  You may not use
- * this file except in compliance with the License.  You can obtain a copy
- * in the file LICENSE in the source distribution or at
- * https://www.openssl.org/source/license.html
- */
-
-/* Custom extension utility functions */
-
-#include <openssl/ct.h>
+/* 
+ * Copyright 2014-2018 The OpenSSL Project Authors. All Rights Reserved. 
+ * 
+ * Licensed under the OpenSSL license (the "License").  You may not use 
+ * this file except in compliance with the License.  You can obtain a copy 
+ * in the file LICENSE in the source distribution or at 
+ * https://www.openssl.org/source/license.html 
+ */ 
+ 
+/* Custom extension utility functions */ 
+ 
+#include <openssl/ct.h> 
 #include "../ssl_local.h"
-#include "internal/cryptlib.h"
+#include "internal/cryptlib.h" 
 #include "statem_local.h"
-
-typedef struct {
-    void *add_arg;
-    custom_ext_add_cb add_cb;
-    custom_ext_free_cb free_cb;
-} custom_ext_add_cb_wrap;
-
-typedef struct {
-    void *parse_arg;
-    custom_ext_parse_cb parse_cb;
-} custom_ext_parse_cb_wrap;
-
-/*
- * Provide thin wrapper callbacks which convert new style arguments to old style
- */
-static int custom_ext_add_old_cb_wrap(SSL *s, unsigned int ext_type,
-                                      unsigned int context,
-                                      const unsigned char **out,
-                                      size_t *outlen, X509 *x, size_t chainidx,
-                                      int *al, void *add_arg)
-{
-    custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;
-
-    if (add_cb_wrap->add_cb == NULL)
-        return 1;
-
-    return add_cb_wrap->add_cb(s, ext_type, out, outlen, al,
-                               add_cb_wrap->add_arg);
-}
-
-static void custom_ext_free_old_cb_wrap(SSL *s, unsigned int ext_type,
-                                        unsigned int context,
-                                        const unsigned char *out, void *add_arg)
-{
-    custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;
-
-    if (add_cb_wrap->free_cb == NULL)
-        return;
-
-    add_cb_wrap->free_cb(s, ext_type, out, add_cb_wrap->add_arg);
-}
-
-static int custom_ext_parse_old_cb_wrap(SSL *s, unsigned int ext_type,
-                                        unsigned int context,
-                                        const unsigned char *in,
-                                        size_t inlen, X509 *x, size_t chainidx,
-                                        int *al, void *parse_arg)
-{
-    custom_ext_parse_cb_wrap *parse_cb_wrap =
-        (custom_ext_parse_cb_wrap *)parse_arg;
-
-    if (parse_cb_wrap->parse_cb == NULL)
-        return 1;
-
-    return parse_cb_wrap->parse_cb(s, ext_type, in, inlen, al,
-                                   parse_cb_wrap->parse_arg);
-}
-
-/*
- * Find a custom extension from the list. The |role| param is there to
- * support the legacy API where custom extensions for client and server could
- * be set independently on the same SSL_CTX. It is set to ENDPOINT_SERVER if we
- * are trying to find a method relevant to the server, ENDPOINT_CLIENT for the
- * client, or ENDPOINT_BOTH for either
- */
-custom_ext_method *custom_ext_find(const custom_ext_methods *exts,
-                                   ENDPOINT role, unsigned int ext_type,
-                                   size_t *idx)
-{
-    size_t i;
-    custom_ext_method *meth = exts->meths;
-
-    for (i = 0; i < exts->meths_count; i++, meth++) {
-        if (ext_type == meth->ext_type
-                && (role == ENDPOINT_BOTH || role == meth->role
-                    || meth->role == ENDPOINT_BOTH)) {
-            if (idx != NULL)
-                *idx = i;
-            return meth;
-        }
-    }
-    return NULL;
-}
-
-/*
- * Initialise custom extensions flags to indicate neither sent nor received.
- */
-void custom_ext_init(custom_ext_methods *exts)
-{
-    size_t i;
-    custom_ext_method *meth = exts->meths;
-
-    for (i = 0; i < exts->meths_count; i++, meth++)
-        meth->ext_flags = 0;
-}
-
-/* Pass received custom extension data to the application for parsing. */
-int custom_ext_parse(SSL *s, unsigned int context, unsigned int ext_type,
-                     const unsigned char *ext_data, size_t ext_size, X509 *x,
-                     size_t chainidx)
-{
-    int al;
-    custom_ext_methods *exts = &s->cert->custext;
-    custom_ext_method *meth;
-    ENDPOINT role = ENDPOINT_BOTH;
-
-    if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0)
-        role = s->server ? ENDPOINT_SERVER : ENDPOINT_CLIENT;
-
-    meth = custom_ext_find(exts, role, ext_type, NULL);
-    /* If not found return success */
-    if (!meth)
-        return 1;
-
-    /* Check if extension is defined for our protocol. If not, skip */
-    if (!extension_is_relevant(s, meth->context, context))
-        return 1;
-
-    if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
-                    | SSL_EXT_TLS1_3_SERVER_HELLO
-                    | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) {
-        /*
-         * If it's ServerHello or EncryptedExtensions we can't have any
-         * extensions not sent in ClientHello.
-         */
-        if ((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0) {
-            SSLfatal(s, TLS1_AD_UNSUPPORTED_EXTENSION, SSL_F_CUSTOM_EXT_PARSE,
-                     SSL_R_BAD_EXTENSION);
-            return 0;
-        }
-    }
-
-    /*
-     * Extensions received in the ClientHello are marked with the
-     * SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent
-     * extensions in the ServerHello/EncryptedExtensions message
-     */
-    if ((context & SSL_EXT_CLIENT_HELLO) != 0)
-        meth->ext_flags |= SSL_EXT_FLAG_RECEIVED;
-
-    /* If no parse function set return success */
-    if (!meth->parse_cb)
-        return 1;
-
-    if (meth->parse_cb(s, ext_type, context, ext_data, ext_size, x, chainidx,
-                       &al, meth->parse_arg) <= 0) {
-        SSLfatal(s, al, SSL_F_CUSTOM_EXT_PARSE, SSL_R_BAD_EXTENSION);
-        return 0;
-    }
-
-    return 1;
-}
-
-/*
- * Request custom extension data from the application and add to the return
- * buffer.
- */
-int custom_ext_add(SSL *s, int context, WPACKET *pkt, X509 *x, size_t chainidx,
-                   int maxversion)
-{
-    custom_ext_methods *exts = &s->cert->custext;
-    custom_ext_method *meth;
-    size_t i;
-    int al;
-
-    for (i = 0; i < exts->meths_count; i++) {
-        const unsigned char *out = NULL;
-        size_t outlen = 0;
-
-        meth = exts->meths + i;
-
-        if (!should_add_extension(s, meth->context, context, maxversion))
-            continue;
-
-        if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
-                        | SSL_EXT_TLS1_3_SERVER_HELLO
-                        | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
-                        | SSL_EXT_TLS1_3_CERTIFICATE
-                        | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) {
-            /* Only send extensions present in ClientHello. */
-            if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
-                continue;
-        }
-        /*
-         * We skip it if the callback is absent - except for a ClientHello where
-         * we add an empty extension.
-         */
-        if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL)
-            continue;
-
-        if (meth->add_cb != NULL) {
-            int cb_retval = meth->add_cb(s, meth->ext_type, context, &out,
-                                         &outlen, x, chainidx, &al,
-                                         meth->add_arg);
-
-            if (cb_retval < 0) {
-                SSLfatal(s, al, SSL_F_CUSTOM_EXT_ADD, SSL_R_CALLBACK_FAILED);
-                return 0;       /* error */
-            }
-            if (cb_retval == 0)
-                continue;       /* skip this extension */
-        }
-
-        if (!WPACKET_put_bytes_u16(pkt, meth->ext_type)
-                || !WPACKET_start_sub_packet_u16(pkt)
-                || (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen))
-                || !WPACKET_close(pkt)) {
-            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CUSTOM_EXT_ADD,
-                     ERR_R_INTERNAL_ERROR);
-            return 0;
-        }
-        if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
-            /*
-             * We can't send duplicates: code logic should prevent this.
-             */
-            if (!ossl_assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0)) {
-                SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CUSTOM_EXT_ADD,
-                         ERR_R_INTERNAL_ERROR);
-                return 0;
-            }
-            /*
-             * Indicate extension has been sent: this is both a sanity check to
-             * ensure we don't send duplicate extensions and indicates that it
-             * is not an error if the extension is present in ServerHello.
-             */
-            meth->ext_flags |= SSL_EXT_FLAG_SENT;
-        }
-        if (meth->free_cb != NULL)
-            meth->free_cb(s, meth->ext_type, context, out, meth->add_arg);
-    }
-    return 1;
-}
-
-/* Copy the flags from src to dst for any extensions that exist in both */
-int custom_exts_copy_flags(custom_ext_methods *dst,
-                           const custom_ext_methods *src)
-{
-    size_t i;
-    custom_ext_method *methsrc = src->meths;
-
-    for (i = 0; i < src->meths_count; i++, methsrc++) {
-        custom_ext_method *methdst = custom_ext_find(dst, methsrc->role,
-                                                     methsrc->ext_type, NULL);
-
-        if (methdst == NULL)
-            continue;
-
-        methdst->ext_flags = methsrc->ext_flags;
-    }
-
-    return 1;
-}
-
-/* Copy table of custom extensions */
-int custom_exts_copy(custom_ext_methods *dst, const custom_ext_methods *src)
-{
-    size_t i;
-    int err = 0;
-
-    if (src->meths_count > 0) {
-        dst->meths =
-            OPENSSL_memdup(src->meths,
-                           sizeof(*src->meths) * src->meths_count);
-        if (dst->meths == NULL)
-            return 0;
-        dst->meths_count = src->meths_count;
-
-        for (i = 0; i < src->meths_count; i++) {
-            custom_ext_method *methsrc = src->meths + i;
-            custom_ext_method *methdst = dst->meths + i;
-
-            if (methsrc->add_cb != custom_ext_add_old_cb_wrap)
-                continue;
-
-            /*
-             * We have found an old style API wrapper. We need to copy the
-             * arguments too.
-             */
-
-            if (err) {
-                methdst->add_arg = NULL;
-                methdst->parse_arg = NULL;
-                continue;
-            }
-
-            methdst->add_arg = OPENSSL_memdup(methsrc->add_arg,
-                                              sizeof(custom_ext_add_cb_wrap));
-            methdst->parse_arg = OPENSSL_memdup(methsrc->parse_arg,
-                                            sizeof(custom_ext_parse_cb_wrap));
-
-            if (methdst->add_arg == NULL || methdst->parse_arg == NULL)
-                err = 1;
-        }
-    }
-
-    if (err) {
-        custom_exts_free(dst);
-        return 0;
-    }
-
-    return 1;
-}
-
-void custom_exts_free(custom_ext_methods *exts)
-{
-    size_t i;
-    custom_ext_method *meth;
-
-    for (i = 0, meth = exts->meths; i < exts->meths_count; i++, meth++) {
-        if (meth->add_cb != custom_ext_add_old_cb_wrap)
-            continue;
-
-        /* Old style API wrapper. Need to free the arguments too */
-        OPENSSL_free(meth->add_arg);
-        OPENSSL_free(meth->parse_arg);
-    }
-    OPENSSL_free(exts->meths);
-}
-
-/* Return true if a client custom extension exists, false otherwise */
-int SSL_CTX_has_client_custom_ext(const SSL_CTX *ctx, unsigned int ext_type)
-{
-    return custom_ext_find(&ctx->cert->custext, ENDPOINT_CLIENT, ext_type,
-                           NULL) != NULL;
-}
-
-static int add_custom_ext_intern(SSL_CTX *ctx, ENDPOINT role,
-                                 unsigned int ext_type,
-                                 unsigned int context,
-                                 SSL_custom_ext_add_cb_ex add_cb,
-                                 SSL_custom_ext_free_cb_ex free_cb,
-                                 void *add_arg,
-                                 SSL_custom_ext_parse_cb_ex parse_cb,
-                                 void *parse_arg)
-{
-    custom_ext_methods *exts = &ctx->cert->custext;
-    custom_ext_method *meth, *tmp;
-
-    /*
-     * Check application error: if add_cb is not set free_cb will never be
-     * called.
-     */
-    if (add_cb == NULL && free_cb != NULL)
-        return 0;
-
-#ifndef OPENSSL_NO_CT
-    /*
-     * We don't want applications registering callbacks for SCT extensions
-     * whilst simultaneously using the built-in SCT validation features, as
-     * these two things may not play well together.
-     */
-    if (ext_type == TLSEXT_TYPE_signed_certificate_timestamp
-            && (context & SSL_EXT_CLIENT_HELLO) != 0
-            && SSL_CTX_ct_is_enabled(ctx))
-        return 0;
-#endif
-
-    /*
-     * Don't add if extension supported internally, but make exception
-     * for extension types that previously were not supported, but now are.
-     */
-    if (SSL_extension_supported(ext_type)
-            && ext_type != TLSEXT_TYPE_signed_certificate_timestamp)
-        return 0;
-
-    /* Extension type must fit in 16 bits */
-    if (ext_type > 0xffff)
-        return 0;
-    /* Search for duplicate */
-    if (custom_ext_find(exts, role, ext_type, NULL))
-        return 0;
-    tmp = OPENSSL_realloc(exts->meths,
-                          (exts->meths_count + 1) * sizeof(custom_ext_method));
-    if (tmp == NULL)
-        return 0;
-
-    exts->meths = tmp;
-    meth = exts->meths + exts->meths_count;
-    memset(meth, 0, sizeof(*meth));
-    meth->role = role;
-    meth->context = context;
-    meth->parse_cb = parse_cb;
-    meth->add_cb = add_cb;
-    meth->free_cb = free_cb;
-    meth->ext_type = ext_type;
-    meth->add_arg = add_arg;
-    meth->parse_arg = parse_arg;
-    exts->meths_count++;
-    return 1;
-}
-
-static int add_old_custom_ext(SSL_CTX *ctx, ENDPOINT role,
-                              unsigned int ext_type,
-                              unsigned int context,
-                              custom_ext_add_cb add_cb,
-                              custom_ext_free_cb free_cb,
-                              void *add_arg,
-                              custom_ext_parse_cb parse_cb, void *parse_arg)
-{
-    custom_ext_add_cb_wrap *add_cb_wrap
-        = OPENSSL_malloc(sizeof(*add_cb_wrap));
-    custom_ext_parse_cb_wrap *parse_cb_wrap
-        = OPENSSL_malloc(sizeof(*parse_cb_wrap));
-    int ret;
-
-    if (add_cb_wrap == NULL || parse_cb_wrap == NULL) {
-        OPENSSL_free(add_cb_wrap);
-        OPENSSL_free(parse_cb_wrap);
-        return 0;
-    }
-
-    add_cb_wrap->add_arg = add_arg;
-    add_cb_wrap->add_cb = add_cb;
-    add_cb_wrap->free_cb = free_cb;
-    parse_cb_wrap->parse_arg = parse_arg;
-    parse_cb_wrap->parse_cb = parse_cb;
-
-    ret = add_custom_ext_intern(ctx, role, ext_type,
-                                context,
-                                custom_ext_add_old_cb_wrap,
-                                custom_ext_free_old_cb_wrap,
-                                add_cb_wrap,
-                                custom_ext_parse_old_cb_wrap,
-                                parse_cb_wrap);
-
-    if (!ret) {
-        OPENSSL_free(add_cb_wrap);
-        OPENSSL_free(parse_cb_wrap);
-    }
-
-    return ret;
-}
-
-/* Application level functions to add the old custom extension callbacks */
-int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
-                                  custom_ext_add_cb add_cb,
-                                  custom_ext_free_cb free_cb,
-                                  void *add_arg,
-                                  custom_ext_parse_cb parse_cb, void *parse_arg)
-{
-    return add_old_custom_ext(ctx, ENDPOINT_CLIENT, ext_type,
-                              SSL_EXT_TLS1_2_AND_BELOW_ONLY
-                              | SSL_EXT_CLIENT_HELLO
-                              | SSL_EXT_TLS1_2_SERVER_HELLO
-                              | SSL_EXT_IGNORE_ON_RESUMPTION,
-                              add_cb, free_cb, add_arg, parse_cb, parse_arg);
-}
-
-int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
-                                  custom_ext_add_cb add_cb,
-                                  custom_ext_free_cb free_cb,
-                                  void *add_arg,
-                                  custom_ext_parse_cb parse_cb, void *parse_arg)
-{
-    return add_old_custom_ext(ctx, ENDPOINT_SERVER, ext_type,
-                              SSL_EXT_TLS1_2_AND_BELOW_ONLY
-                              | SSL_EXT_CLIENT_HELLO
-                              | SSL_EXT_TLS1_2_SERVER_HELLO
-                              | SSL_EXT_IGNORE_ON_RESUMPTION,
-                              add_cb, free_cb, add_arg, parse_cb, parse_arg);
-}
-
-int SSL_CTX_add_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
-                           unsigned int context,
-                           SSL_custom_ext_add_cb_ex add_cb,
-                           SSL_custom_ext_free_cb_ex free_cb,
-                           void *add_arg,
-                           SSL_custom_ext_parse_cb_ex parse_cb, void *parse_arg)
-{
-    return add_custom_ext_intern(ctx, ENDPOINT_BOTH, ext_type, context, add_cb,
-                                 free_cb, add_arg, parse_cb, parse_arg);
-}
-
-int SSL_extension_supported(unsigned int ext_type)
-{
-    switch (ext_type) {
-        /* Internally supported extensions. */
-    case TLSEXT_TYPE_application_layer_protocol_negotiation:
-#ifndef OPENSSL_NO_EC
-    case TLSEXT_TYPE_ec_point_formats:
-    case TLSEXT_TYPE_supported_groups:
-    case TLSEXT_TYPE_key_share:
-#endif
-#ifndef OPENSSL_NO_NEXTPROTONEG
-    case TLSEXT_TYPE_next_proto_neg:
-#endif
-    case TLSEXT_TYPE_padding:
-    case TLSEXT_TYPE_renegotiate:
-    case TLSEXT_TYPE_max_fragment_length:
-    case TLSEXT_TYPE_server_name:
-    case TLSEXT_TYPE_session_ticket:
-    case TLSEXT_TYPE_signature_algorithms:
-#ifndef OPENSSL_NO_SRP
-    case TLSEXT_TYPE_srp:
-#endif
-#ifndef OPENSSL_NO_OCSP
-    case TLSEXT_TYPE_status_request:
-#endif
-#ifndef OPENSSL_NO_CT
-    case TLSEXT_TYPE_signed_certificate_timestamp:
-#endif
-#ifndef OPENSSL_NO_SRTP
-    case TLSEXT_TYPE_use_srtp:
-#endif
-    case TLSEXT_TYPE_encrypt_then_mac:
-    case TLSEXT_TYPE_supported_versions:
-    case TLSEXT_TYPE_extended_master_secret:
-    case TLSEXT_TYPE_psk_kex_modes:
-    case TLSEXT_TYPE_cookie:
-    case TLSEXT_TYPE_early_data:
-    case TLSEXT_TYPE_certificate_authorities:
-    case TLSEXT_TYPE_psk:
-    case TLSEXT_TYPE_post_handshake_auth:
-        return 1;
-    default:
-        return 0;
-    }
-}
+ 
+typedef struct { 
+    void *add_arg; 
+    custom_ext_add_cb add_cb; 
+    custom_ext_free_cb free_cb; 
+} custom_ext_add_cb_wrap; 
+ 
+typedef struct { 
+    void *parse_arg; 
+    custom_ext_parse_cb parse_cb; 
+} custom_ext_parse_cb_wrap; 
+ 
+/* 
+ * Provide thin wrapper callbacks which convert new style arguments to old style 
+ */ 
+static int custom_ext_add_old_cb_wrap(SSL *s, unsigned int ext_type, 
+                                      unsigned int context, 
+                                      const unsigned char **out, 
+                                      size_t *outlen, X509 *x, size_t chainidx, 
+                                      int *al, void *add_arg) 
+{ 
+    custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg; 
+ 
+    if (add_cb_wrap->add_cb == NULL) 
+        return 1; 
+ 
+    return add_cb_wrap->add_cb(s, ext_type, out, outlen, al, 
+                               add_cb_wrap->add_arg); 
+} 
+ 
+static void custom_ext_free_old_cb_wrap(SSL *s, unsigned int ext_type, 
+                                        unsigned int context, 
+                                        const unsigned char *out, void *add_arg) 
+{ 
+    custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg; 
+ 
+    if (add_cb_wrap->free_cb == NULL) 
+        return; 
+ 
+    add_cb_wrap->free_cb(s, ext_type, out, add_cb_wrap->add_arg); 
+} 
+ 
+static int custom_ext_parse_old_cb_wrap(SSL *s, unsigned int ext_type, 
+                                        unsigned int context, 
+                                        const unsigned char *in, 
+                                        size_t inlen, X509 *x, size_t chainidx, 
+                                        int *al, void *parse_arg) 
+{ 
+    custom_ext_parse_cb_wrap *parse_cb_wrap = 
+        (custom_ext_parse_cb_wrap *)parse_arg; 
+ 
+    if (parse_cb_wrap->parse_cb == NULL) 
+        return 1; 
+ 
+    return parse_cb_wrap->parse_cb(s, ext_type, in, inlen, al, 
+                                   parse_cb_wrap->parse_arg); 
+} 
+ 
+/* 
+ * Find a custom extension from the list. The |role| param is there to 
+ * support the legacy API where custom extensions for client and server could 
+ * be set independently on the same SSL_CTX. It is set to ENDPOINT_SERVER if we 
+ * are trying to find a method relevant to the server, ENDPOINT_CLIENT for the 
+ * client, or ENDPOINT_BOTH for either 
+ */ 
+custom_ext_method *custom_ext_find(const custom_ext_methods *exts, 
+                                   ENDPOINT role, unsigned int ext_type, 
+                                   size_t *idx) 
+{ 
+    size_t i; 
+    custom_ext_method *meth = exts->meths; 
+ 
+    for (i = 0; i < exts->meths_count; i++, meth++) { 
+        if (ext_type == meth->ext_type 
+                && (role == ENDPOINT_BOTH || role == meth->role 
+                    || meth->role == ENDPOINT_BOTH)) { 
+            if (idx != NULL) 
+                *idx = i; 
+            return meth; 
+        } 
+    } 
+    return NULL; 
+} 
+ 
+/* 
+ * Initialise custom extensions flags to indicate neither sent nor received. 
+ */ 
+void custom_ext_init(custom_ext_methods *exts) 
+{ 
+    size_t i; 
+    custom_ext_method *meth = exts->meths; 
+ 
+    for (i = 0; i < exts->meths_count; i++, meth++) 
+        meth->ext_flags = 0; 
+} 
+ 
+/* Pass received custom extension data to the application for parsing. */ 
+int custom_ext_parse(SSL *s, unsigned int context, unsigned int ext_type, 
+                     const unsigned char *ext_data, size_t ext_size, X509 *x, 
+                     size_t chainidx) 
+{ 
+    int al; 
+    custom_ext_methods *exts = &s->cert->custext; 
+    custom_ext_method *meth; 
+    ENDPOINT role = ENDPOINT_BOTH; 
+ 
+    if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0) 
+        role = s->server ? ENDPOINT_SERVER : ENDPOINT_CLIENT; 
+ 
+    meth = custom_ext_find(exts, role, ext_type, NULL); 
+    /* If not found return success */ 
+    if (!meth) 
+        return 1; 
+ 
+    /* Check if extension is defined for our protocol. If not, skip */ 
+    if (!extension_is_relevant(s, meth->context, context)) 
+        return 1; 
+ 
+    if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO 
+                    | SSL_EXT_TLS1_3_SERVER_HELLO 
+                    | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) { 
+        /* 
+         * If it's ServerHello or EncryptedExtensions we can't have any 
+         * extensions not sent in ClientHello. 
+         */ 
+        if ((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0) { 
+            SSLfatal(s, TLS1_AD_UNSUPPORTED_EXTENSION, SSL_F_CUSTOM_EXT_PARSE, 
+                     SSL_R_BAD_EXTENSION); 
+            return 0; 
+        } 
+    } 
+ 
+    /* 
+     * Extensions received in the ClientHello are marked with the 
+     * SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent 
+     * extensions in the ServerHello/EncryptedExtensions message 
+     */ 
+    if ((context & SSL_EXT_CLIENT_HELLO) != 0) 
+        meth->ext_flags |= SSL_EXT_FLAG_RECEIVED; 
+ 
+    /* If no parse function set return success */ 
+    if (!meth->parse_cb) 
+        return 1; 
+ 
+    if (meth->parse_cb(s, ext_type, context, ext_data, ext_size, x, chainidx, 
+                       &al, meth->parse_arg) <= 0) { 
+        SSLfatal(s, al, SSL_F_CUSTOM_EXT_PARSE, SSL_R_BAD_EXTENSION); 
+        return 0; 
+    } 
+ 
+    return 1; 
+} 
+ 
+/* 
+ * Request custom extension data from the application and add to the return 
+ * buffer. 
+ */ 
+int custom_ext_add(SSL *s, int context, WPACKET *pkt, X509 *x, size_t chainidx, 
+                   int maxversion) 
+{ 
+    custom_ext_methods *exts = &s->cert->custext; 
+    custom_ext_method *meth; 
+    size_t i; 
+    int al; 
+ 
+    for (i = 0; i < exts->meths_count; i++) { 
+        const unsigned char *out = NULL; 
+        size_t outlen = 0; 
+ 
+        meth = exts->meths + i; 
+ 
+        if (!should_add_extension(s, meth->context, context, maxversion)) 
+            continue; 
+ 
+        if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO 
+                        | SSL_EXT_TLS1_3_SERVER_HELLO 
+                        | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS 
+                        | SSL_EXT_TLS1_3_CERTIFICATE 
+                        | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) { 
+            /* Only send extensions present in ClientHello. */ 
+            if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED)) 
+                continue; 
+        } 
+        /* 
+         * We skip it if the callback is absent - except for a ClientHello where 
+         * we add an empty extension. 
+         */ 
+        if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL) 
+            continue; 
+ 
+        if (meth->add_cb != NULL) { 
+            int cb_retval = meth->add_cb(s, meth->ext_type, context, &out, 
+                                         &outlen, x, chainidx, &al, 
+                                         meth->add_arg); 
+ 
+            if (cb_retval < 0) { 
+                SSLfatal(s, al, SSL_F_CUSTOM_EXT_ADD, SSL_R_CALLBACK_FAILED); 
+                return 0;       /* error */ 
+            } 
+            if (cb_retval == 0) 
+                continue;       /* skip this extension */ 
+        } 
+ 
+        if (!WPACKET_put_bytes_u16(pkt, meth->ext_type) 
+                || !WPACKET_start_sub_packet_u16(pkt) 
+                || (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen)) 
+                || !WPACKET_close(pkt)) { 
+            SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CUSTOM_EXT_ADD, 
+                     ERR_R_INTERNAL_ERROR); 
+            return 0; 
+        } 
+        if ((context & SSL_EXT_CLIENT_HELLO) != 0) { 
+            /* 
+             * We can't send duplicates: code logic should prevent this. 
+             */ 
+            if (!ossl_assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0)) { 
+                SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CUSTOM_EXT_ADD, 
+                         ERR_R_INTERNAL_ERROR); 
+                return 0; 
+            } 
+            /* 
+             * Indicate extension has been sent: this is both a sanity check to 
+             * ensure we don't send duplicate extensions and indicates that it 
+             * is not an error if the extension is present in ServerHello. 
+             */ 
+            meth->ext_flags |= SSL_EXT_FLAG_SENT; 
+        } 
+        if (meth->free_cb != NULL) 
+            meth->free_cb(s, meth->ext_type, context, out, meth->add_arg); 
+    } 
+    return 1; 
+} 
+ 
+/* Copy the flags from src to dst for any extensions that exist in both */ 
+int custom_exts_copy_flags(custom_ext_methods *dst, 
+                           const custom_ext_methods *src) 
+{ 
+    size_t i; 
+    custom_ext_method *methsrc = src->meths; 
+ 
+    for (i = 0; i < src->meths_count; i++, methsrc++) { 
+        custom_ext_method *methdst = custom_ext_find(dst, methsrc->role, 
+                                                     methsrc->ext_type, NULL); 
+ 
+        if (methdst == NULL) 
+            continue; 
+ 
+        methdst->ext_flags = methsrc->ext_flags; 
+    } 
+ 
+    return 1; 
+} 
+ 
+/* Copy table of custom extensions */ 
+int custom_exts_copy(custom_ext_methods *dst, const custom_ext_methods *src) 
+{ 
+    size_t i; 
+    int err = 0; 
+ 
+    if (src->meths_count > 0) { 
+        dst->meths = 
+            OPENSSL_memdup(src->meths, 
+                           sizeof(*src->meths) * src->meths_count); 
+        if (dst->meths == NULL) 
+            return 0; 
+        dst->meths_count = src->meths_count; 
+ 
+        for (i = 0; i < src->meths_count; i++) { 
+            custom_ext_method *methsrc = src->meths + i; 
+            custom_ext_method *methdst = dst->meths + i; 
+ 
+            if (methsrc->add_cb != custom_ext_add_old_cb_wrap) 
+                continue; 
+ 
+            /* 
+             * We have found an old style API wrapper. We need to copy the 
+             * arguments too. 
+             */ 
+ 
+            if (err) { 
+                methdst->add_arg = NULL; 
+                methdst->parse_arg = NULL; 
+                continue; 
+            } 
+ 
+            methdst->add_arg = OPENSSL_memdup(methsrc->add_arg, 
+                                              sizeof(custom_ext_add_cb_wrap)); 
+            methdst->parse_arg = OPENSSL_memdup(methsrc->parse_arg, 
+                                            sizeof(custom_ext_parse_cb_wrap)); 
+ 
+            if (methdst->add_arg == NULL || methdst->parse_arg == NULL) 
+                err = 1; 
+        } 
+    } 
+ 
+    if (err) { 
+        custom_exts_free(dst); 
+        return 0; 
+    } 
+ 
+    return 1; 
+} 
+ 
+void custom_exts_free(custom_ext_methods *exts) 
+{ 
+    size_t i; 
+    custom_ext_method *meth; 
+ 
+    for (i = 0, meth = exts->meths; i < exts->meths_count; i++, meth++) { 
+        if (meth->add_cb != custom_ext_add_old_cb_wrap) 
+            continue; 
+ 
+        /* Old style API wrapper. Need to free the arguments too */ 
+        OPENSSL_free(meth->add_arg); 
+        OPENSSL_free(meth->parse_arg); 
+    } 
+    OPENSSL_free(exts->meths); 
+} 
+ 
+/* Return true if a client custom extension exists, false otherwise */ 
+int SSL_CTX_has_client_custom_ext(const SSL_CTX *ctx, unsigned int ext_type) 
+{ 
+    return custom_ext_find(&ctx->cert->custext, ENDPOINT_CLIENT, ext_type, 
+                           NULL) != NULL; 
+} 
+ 
+static int add_custom_ext_intern(SSL_CTX *ctx, ENDPOINT role, 
+                                 unsigned int ext_type, 
+                                 unsigned int context, 
+                                 SSL_custom_ext_add_cb_ex add_cb, 
+                                 SSL_custom_ext_free_cb_ex free_cb, 
+                                 void *add_arg, 
+                                 SSL_custom_ext_parse_cb_ex parse_cb, 
+                                 void *parse_arg) 
+{ 
+    custom_ext_methods *exts = &ctx->cert->custext; 
+    custom_ext_method *meth, *tmp; 
+ 
+    /* 
+     * Check application error: if add_cb is not set free_cb will never be 
+     * called. 
+     */ 
+    if (add_cb == NULL && free_cb != NULL) 
+        return 0; 
+ 
+#ifndef OPENSSL_NO_CT 
+    /* 
+     * We don't want applications registering callbacks for SCT extensions 
+     * whilst simultaneously using the built-in SCT validation features, as 
+     * these two things may not play well together. 
+     */ 
+    if (ext_type == TLSEXT_TYPE_signed_certificate_timestamp 
+            && (context & SSL_EXT_CLIENT_HELLO) != 0 
+            && SSL_CTX_ct_is_enabled(ctx)) 
+        return 0; 
+#endif 
+ 
+    /* 
+     * Don't add if extension supported internally, but make exception 
+     * for extension types that previously were not supported, but now are. 
+     */ 
+    if (SSL_extension_supported(ext_type) 
+            && ext_type != TLSEXT_TYPE_signed_certificate_timestamp) 
+        return 0; 
+ 
+    /* Extension type must fit in 16 bits */ 
+    if (ext_type > 0xffff) 
+        return 0; 
+    /* Search for duplicate */ 
+    if (custom_ext_find(exts, role, ext_type, NULL)) 
+        return 0; 
+    tmp = OPENSSL_realloc(exts->meths, 
+                          (exts->meths_count + 1) * sizeof(custom_ext_method)); 
+    if (tmp == NULL) 
+        return 0; 
+ 
+    exts->meths = tmp; 
+    meth = exts->meths + exts->meths_count; 
+    memset(meth, 0, sizeof(*meth)); 
+    meth->role = role; 
+    meth->context = context; 
+    meth->parse_cb = parse_cb; 
+    meth->add_cb = add_cb; 
+    meth->free_cb = free_cb; 
+    meth->ext_type = ext_type; 
+    meth->add_arg = add_arg; 
+    meth->parse_arg = parse_arg; 
+    exts->meths_count++; 
+    return 1; 
+} 
+ 
+static int add_old_custom_ext(SSL_CTX *ctx, ENDPOINT role, 
+                              unsigned int ext_type, 
+                              unsigned int context, 
+                              custom_ext_add_cb add_cb, 
+                              custom_ext_free_cb free_cb, 
+                              void *add_arg, 
+                              custom_ext_parse_cb parse_cb, void *parse_arg) 
+{ 
+    custom_ext_add_cb_wrap *add_cb_wrap 
+        = OPENSSL_malloc(sizeof(*add_cb_wrap)); 
+    custom_ext_parse_cb_wrap *parse_cb_wrap 
+        = OPENSSL_malloc(sizeof(*parse_cb_wrap)); 
+    int ret; 
+ 
+    if (add_cb_wrap == NULL || parse_cb_wrap == NULL) { 
+        OPENSSL_free(add_cb_wrap); 
+        OPENSSL_free(parse_cb_wrap); 
+        return 0; 
+    } 
+ 
+    add_cb_wrap->add_arg = add_arg; 
+    add_cb_wrap->add_cb = add_cb; 
+    add_cb_wrap->free_cb = free_cb; 
+    parse_cb_wrap->parse_arg = parse_arg; 
+    parse_cb_wrap->parse_cb = parse_cb; 
+ 
+    ret = add_custom_ext_intern(ctx, role, ext_type, 
+                                context, 
+                                custom_ext_add_old_cb_wrap, 
+                                custom_ext_free_old_cb_wrap, 
+                                add_cb_wrap, 
+                                custom_ext_parse_old_cb_wrap, 
+                                parse_cb_wrap); 
+ 
+    if (!ret) { 
+        OPENSSL_free(add_cb_wrap); 
+        OPENSSL_free(parse_cb_wrap); 
+    } 
+ 
+    return ret; 
+} 
+ 
+/* Application level functions to add the old custom extension callbacks */ 
+int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type, 
+                                  custom_ext_add_cb add_cb, 
+                                  custom_ext_free_cb free_cb, 
+                                  void *add_arg, 
+                                  custom_ext_parse_cb parse_cb, void *parse_arg) 
+{ 
+    return add_old_custom_ext(ctx, ENDPOINT_CLIENT, ext_type, 
+                              SSL_EXT_TLS1_2_AND_BELOW_ONLY 
+                              | SSL_EXT_CLIENT_HELLO 
+                              | SSL_EXT_TLS1_2_SERVER_HELLO 
+                              | SSL_EXT_IGNORE_ON_RESUMPTION, 
+                              add_cb, free_cb, add_arg, parse_cb, parse_arg); 
+} 
+ 
+int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type, 
+                                  custom_ext_add_cb add_cb, 
+                                  custom_ext_free_cb free_cb, 
+                                  void *add_arg, 
+                                  custom_ext_parse_cb parse_cb, void *parse_arg) 
+{ 
+    return add_old_custom_ext(ctx, ENDPOINT_SERVER, ext_type, 
+                              SSL_EXT_TLS1_2_AND_BELOW_ONLY 
+                              | SSL_EXT_CLIENT_HELLO 
+                              | SSL_EXT_TLS1_2_SERVER_HELLO 
+                              | SSL_EXT_IGNORE_ON_RESUMPTION, 
+                              add_cb, free_cb, add_arg, parse_cb, parse_arg); 
+} 
+ 
+int SSL_CTX_add_custom_ext(SSL_CTX *ctx, unsigned int ext_type, 
+                           unsigned int context, 
+                           SSL_custom_ext_add_cb_ex add_cb, 
+                           SSL_custom_ext_free_cb_ex free_cb, 
+                           void *add_arg, 
+                           SSL_custom_ext_parse_cb_ex parse_cb, void *parse_arg) 
+{ 
+    return add_custom_ext_intern(ctx, ENDPOINT_BOTH, ext_type, context, add_cb, 
+                                 free_cb, add_arg, parse_cb, parse_arg); 
+} 
+ 
+int SSL_extension_supported(unsigned int ext_type) 
+{ 
+    switch (ext_type) { 
+        /* Internally supported extensions. */ 
+    case TLSEXT_TYPE_application_layer_protocol_negotiation: 
+#ifndef OPENSSL_NO_EC 
+    case TLSEXT_TYPE_ec_point_formats: 
+    case TLSEXT_TYPE_supported_groups: 
+    case TLSEXT_TYPE_key_share: 
+#endif 
+#ifndef OPENSSL_NO_NEXTPROTONEG 
+    case TLSEXT_TYPE_next_proto_neg: 
+#endif 
+    case TLSEXT_TYPE_padding: 
+    case TLSEXT_TYPE_renegotiate: 
+    case TLSEXT_TYPE_max_fragment_length: 
+    case TLSEXT_TYPE_server_name: 
+    case TLSEXT_TYPE_session_ticket: 
+    case TLSEXT_TYPE_signature_algorithms: 
+#ifndef OPENSSL_NO_SRP 
+    case TLSEXT_TYPE_srp: 
+#endif 
+#ifndef OPENSSL_NO_OCSP 
+    case TLSEXT_TYPE_status_request: 
+#endif 
+#ifndef OPENSSL_NO_CT 
+    case TLSEXT_TYPE_signed_certificate_timestamp: 
+#endif 
+#ifndef OPENSSL_NO_SRTP 
+    case TLSEXT_TYPE_use_srtp: 
+#endif 
+    case TLSEXT_TYPE_encrypt_then_mac: 
+    case TLSEXT_TYPE_supported_versions: 
+    case TLSEXT_TYPE_extended_master_secret: 
+    case TLSEXT_TYPE_psk_kex_modes: 
+    case TLSEXT_TYPE_cookie: 
+    case TLSEXT_TYPE_early_data: 
+    case TLSEXT_TYPE_certificate_authorities: 
+    case TLSEXT_TYPE_psk: 
+    case TLSEXT_TYPE_post_handshake_auth: 
+        return 1; 
+    default: 
+        return 0; 
+    } 
+}