path: root/contrib/libs/openssl/ssl/statem/extensions_cust.c

/* 
 * 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 "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; 
    } 
}