tzdata: update to 2018g

[unleashed.git] / lib / libssl / t1_lib.c

/* $OpenBSD: t1_lib.c,v 1.144 2018/08/24 18:10:25 jsing Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>

#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/objects.h>
#include <openssl/ocsp.h>

#include "ssl_locl.h"

#include "bytestring.h"
#include "ssl_tlsext.h"

static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
    const unsigned char *sess_id, int sesslen,
    SSL_SESSION **psess);

SSL3_ENC_METHOD TLSv1_enc_data = {
        .enc = tls1_enc,
        .enc_flags = 0,
};

SSL3_ENC_METHOD TLSv1_1_enc_data = {
        .enc = tls1_enc,
        .enc_flags = SSL_ENC_FLAG_EXPLICIT_IV,
};

SSL3_ENC_METHOD TLSv1_2_enc_data = {
        .enc = tls1_enc,
        .enc_flags = SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS|
            SSL_ENC_FLAG_SHA256_PRF|SSL_ENC_FLAG_TLS1_2_CIPHERS,
};

long
tls1_default_timeout(void)
{
        /* 2 hours, the 24 hours mentioned in the TLSv1 spec
         * is way too long for http, the cache would over fill */
        return (60 * 60 * 2);
}

int
tls1_new(SSL *s)
{
        if (!ssl3_new(s))
                return (0);
        s->method->internal->ssl_clear(s);
        return (1);
}

void
tls1_free(SSL *s)
{
        if (s == NULL)
                return;

        free(s->internal->tlsext_session_ticket);
        ssl3_free(s);
}

void
tls1_clear(SSL *s)
{
        ssl3_clear(s);
        s->version = s->method->internal->version;
}

static int nid_list[] = {
        NID_sect163k1,          /* sect163k1 (1) */
        NID_sect163r1,          /* sect163r1 (2) */
        NID_sect163r2,          /* sect163r2 (3) */
        NID_sect193r1,          /* sect193r1 (4) */
        NID_sect193r2,          /* sect193r2 (5) */
        NID_sect233k1,          /* sect233k1 (6) */
        NID_sect233r1,          /* sect233r1 (7) */
        NID_sect239k1,          /* sect239k1 (8) */
        NID_sect283k1,          /* sect283k1 (9) */
        NID_sect283r1,          /* sect283r1 (10) */
        NID_sect409k1,          /* sect409k1 (11) */
        NID_sect409r1,          /* sect409r1 (12) */
        NID_sect571k1,          /* sect571k1 (13) */
        NID_sect571r1,          /* sect571r1 (14) */
        NID_secp160k1,          /* secp160k1 (15) */
        NID_secp160r1,          /* secp160r1 (16) */
        NID_secp160r2,          /* secp160r2 (17) */
        NID_secp192k1,          /* secp192k1 (18) */
        NID_X9_62_prime192v1,   /* secp192r1 (19) */
        NID_secp224k1,          /* secp224k1 (20) */
        NID_secp224r1,          /* secp224r1 (21) */
        NID_secp256k1,          /* secp256k1 (22) */
        NID_X9_62_prime256v1,   /* secp256r1 (23) */
        NID_secp384r1,          /* secp384r1 (24) */
        NID_secp521r1,          /* secp521r1 (25) */
        NID_brainpoolP256r1,    /* brainpoolP256r1 (26) */
        NID_brainpoolP384r1,    /* brainpoolP384r1 (27) */
        NID_brainpoolP512r1,    /* brainpoolP512r1 (28) */
        NID_X25519,             /* X25519 (29) */
};

#if 0
static const uint8_t ecformats_list[] = {
        TLSEXT_ECPOINTFORMAT_uncompressed,
        TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
        TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
};
#endif

static const uint8_t ecformats_default[] = {
        TLSEXT_ECPOINTFORMAT_uncompressed,
};

#if 0
static const uint16_t eccurves_list[] = {
        29,                     /* X25519 (29) */
        14,                     /* sect571r1 (14) */
        13,                     /* sect571k1 (13) */
        25,                     /* secp521r1 (25) */
        28,                     /* brainpoolP512r1 (28) */
        11,                     /* sect409k1 (11) */
        12,                     /* sect409r1 (12) */
        27,                     /* brainpoolP384r1 (27) */
        24,                     /* secp384r1 (24) */
        9,                      /* sect283k1 (9) */
        10,                     /* sect283r1 (10) */
        26,                     /* brainpoolP256r1 (26) */
        22,                     /* secp256k1 (22) */
        23,                     /* secp256r1 (23) */
        8,                      /* sect239k1 (8) */
        6,                      /* sect233k1 (6) */
        7,                      /* sect233r1 (7) */
        20,                     /* secp224k1 (20) */
        21,                     /* secp224r1 (21) */
        4,                      /* sect193r1 (4) */
        5,                      /* sect193r2 (5) */
        18,                     /* secp192k1 (18) */
        19,                     /* secp192r1 (19) */
        1,                      /* sect163k1 (1) */
        2,                      /* sect163r1 (2) */
        3,                      /* sect163r2 (3) */
        15,                     /* secp160k1 (15) */
        16,                     /* secp160r1 (16) */
        17,                     /* secp160r2 (17) */
};
#endif

static const uint16_t eccurves_default[] = {
        29,                     /* X25519 (29) */
        23,                     /* secp256r1 (23) */
        24,                     /* secp384r1 (24) */
};

int
tls1_ec_curve_id2nid(const uint16_t curve_id)
{
        /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
        if ((curve_id < 1) ||
            ((unsigned int)curve_id > sizeof(nid_list) / sizeof(nid_list[0])))
                return 0;
        return nid_list[curve_id - 1];
}

uint16_t
tls1_ec_nid2curve_id(const int nid)
{
        /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
        switch (nid) {
        case NID_sect163k1: /* sect163k1 (1) */
                return 1;
        case NID_sect163r1: /* sect163r1 (2) */
                return 2;
        case NID_sect163r2: /* sect163r2 (3) */
                return 3;
        case NID_sect193r1: /* sect193r1 (4) */
                return 4;
        case NID_sect193r2: /* sect193r2 (5) */
                return 5;
        case NID_sect233k1: /* sect233k1 (6) */
                return 6;
        case NID_sect233r1: /* sect233r1 (7) */
                return 7;
        case NID_sect239k1: /* sect239k1 (8) */
                return 8;
        case NID_sect283k1: /* sect283k1 (9) */
                return 9;
        case NID_sect283r1: /* sect283r1 (10) */
                return 10;
        case NID_sect409k1: /* sect409k1 (11) */
                return 11;
        case NID_sect409r1: /* sect409r1 (12) */
                return 12;
        case NID_sect571k1: /* sect571k1 (13) */
                return 13;
        case NID_sect571r1: /* sect571r1 (14) */
                return 14;
        case NID_secp160k1: /* secp160k1 (15) */
                return 15;
        case NID_secp160r1: /* secp160r1 (16) */
                return 16;
        case NID_secp160r2: /* secp160r2 (17) */
                return 17;
        case NID_secp192k1: /* secp192k1 (18) */
                return 18;
        case NID_X9_62_prime192v1: /* secp192r1 (19) */
                return 19;
        case NID_secp224k1: /* secp224k1 (20) */
                return 20;
        case NID_secp224r1: /* secp224r1 (21) */
                return 21;
        case NID_secp256k1: /* secp256k1 (22) */
                return 22;
        case NID_X9_62_prime256v1: /* secp256r1 (23) */
                return 23;
        case NID_secp384r1: /* secp384r1 (24) */
                return 24;
        case NID_secp521r1: /* secp521r1 (25) */
                return 25;
        case NID_brainpoolP256r1: /* brainpoolP256r1 (26) */
                return 26;
        case NID_brainpoolP384r1: /* brainpoolP384r1 (27) */
                return 27;
        case NID_brainpoolP512r1: /* brainpoolP512r1 (28) */
                return 28;
        case NID_X25519:                /* X25519 (29) */
                return 29;
        default:
                return 0;
        }
}

/*
 * Return the appropriate format list. If client_formats is non-zero, return
 * the client/session formats. Otherwise return the custom format list if one
 * exists, or the default formats if a custom list has not been specified.
 */
void
tls1_get_formatlist(SSL *s, int client_formats, const uint8_t **pformats,
    size_t *pformatslen)
{
        if (client_formats != 0) {
                *pformats = SSI(s)->tlsext_ecpointformatlist;
                *pformatslen = SSI(s)->tlsext_ecpointformatlist_length;
                return;
        }

        *pformats = s->internal->tlsext_ecpointformatlist;
        *pformatslen = s->internal->tlsext_ecpointformatlist_length;
        if (*pformats == NULL) {
                *pformats = ecformats_default;
                *pformatslen = sizeof(ecformats_default);
        }
}

/*
 * Return the appropriate curve list. If client_curves is non-zero, return
 * the client/session curves. Otherwise return the custom curve list if one
 * exists, or the default curves if a custom list has not been specified.
 */
void
tls1_get_curvelist(SSL *s, int client_curves, const uint16_t **pcurves,
    size_t *pcurveslen)
{
        if (client_curves != 0) {
                *pcurves = SSI(s)->tlsext_supportedgroups;
                *pcurveslen = SSI(s)->tlsext_supportedgroups_length;
                return;
        }

        *pcurves = s->internal->tlsext_supportedgroups;
        *pcurveslen = s->internal->tlsext_supportedgroups_length;
        if (*pcurves == NULL) {
                *pcurves = eccurves_default;
                *pcurveslen = sizeof(eccurves_default) / 2;
        }
}

int
tls1_set_groups(uint16_t **out_group_ids, size_t *out_group_ids_len,
    const int *groups, size_t ngroups)
{
        uint16_t *group_ids;
        size_t i;

        group_ids = calloc(ngroups, sizeof(uint16_t));
        if (group_ids == NULL)
                return 0;

        for (i = 0; i < ngroups; i++) {
                group_ids[i] = tls1_ec_nid2curve_id(groups[i]);
                if (group_ids[i] == 0) {
                        free(group_ids);
                        return 0;
                }
        }

        free(*out_group_ids);
        *out_group_ids = group_ids;
        *out_group_ids_len = ngroups;

        return 1;
}

int
tls1_set_groups_list(uint16_t **out_group_ids, size_t *out_group_ids_len,
    const char *groups)
{
        uint16_t *new_group_ids, *group_ids = NULL;
        size_t ngroups = 0;
        char *gs, *p, *q;
        int nid;

        if ((gs = strdup(groups)) == NULL)
                return 0;

        q = gs;
        while ((p = strsep(&q, ":")) != NULL) {
                nid = OBJ_sn2nid(p);
                if (nid == NID_undef)
                        nid = OBJ_ln2nid(p);
                if (nid == NID_undef)
                        nid = EC_curve_nist2nid(p);
                if (nid == NID_undef)
                        goto err;

                if ((new_group_ids = reallocarray(group_ids, ngroups + 1,
                    sizeof(uint16_t))) == NULL)
                        goto err;
                group_ids = new_group_ids;

                group_ids[ngroups] = tls1_ec_nid2curve_id(nid);
                if (group_ids[ngroups] == 0)
                        goto err;

                ngroups++;
        }

        free(gs);
        free(*out_group_ids);
        *out_group_ids = group_ids;
        *out_group_ids_len = ngroups;

        return 1;

 err:
        free(gs);
        free(group_ids);

        return 0;
}

/* Check that a curve is one of our preferences. */
int
tls1_check_curve(SSL *s, const uint16_t curve_id)
{
        const uint16_t *curves;
        size_t curveslen, i;

        tls1_get_curvelist(s, 0, &curves, &curveslen);

        for (i = 0; i < curveslen; i++) {
                if (curves[i] == curve_id)
                        return (1);
        }
        return (0);
}

int
tls1_get_shared_curve(SSL *s)
{
        size_t preflen, supplen, i, j;
        const uint16_t *pref, *supp;
        unsigned long server_pref;

        /* Cannot do anything on the client side. */
        if (s->server == 0)
                return (NID_undef);

        /* Return first preference shared curve. */
        server_pref = (s->internal->options & SSL_OP_CIPHER_SERVER_PREFERENCE);
        tls1_get_curvelist(s, (server_pref == 0), &pref, &preflen);
        tls1_get_curvelist(s, (server_pref != 0), &supp, &supplen);

        for (i = 0; i < preflen; i++) {
                for (j = 0; j < supplen; j++) {
                        if (pref[i] == supp[j])
                                return (tls1_ec_curve_id2nid(pref[i]));
                }
        }
        return (NID_undef);
}

/* For an EC key set TLS ID and required compression based on parameters. */
static int
tls1_set_ec_id(uint16_t *curve_id, uint8_t *comp_id, EC_KEY *ec)
{
        const EC_GROUP *grp;
        const EC_METHOD *meth;
        int is_prime = 0;
        int nid, id;

        if (ec == NULL)
                return (0);

        /* Determine if it is a prime field. */
        if ((grp = EC_KEY_get0_group(ec)) == NULL)
                return (0);
        if ((meth = EC_GROUP_method_of(grp)) == NULL)
                return (0);
        if (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field)
                is_prime = 1;

        /* Determine curve ID. */
        nid = EC_GROUP_get_curve_name(grp);
        id = tls1_ec_nid2curve_id(nid);

        /* If we have an ID set it, otherwise set arbitrary explicit curve. */
        if (id != 0)
                *curve_id = id;
        else
                *curve_id = is_prime ? 0xff01 : 0xff02;

        /* Specify the compression identifier. */
        if (comp_id != NULL) {
                if (EC_KEY_get0_public_key(ec) == NULL)
                        return (0);

                if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED) {
                        *comp_id = is_prime ?
                            TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime :
                            TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
                } else {
                        *comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
                }
        }
        return (1);
}

/* Check that an EC key is compatible with extensions. */
static int
tls1_check_ec_key(SSL *s, const uint16_t *curve_id, const uint8_t *comp_id)
{
        size_t curveslen, formatslen, i;
        const uint16_t *curves;
        const uint8_t *formats;

        /*
         * Check point formats extension if present, otherwise everything
         * is supported (see RFC4492).
         */
        tls1_get_formatlist(s, 1, &formats, &formatslen);
        if (comp_id != NULL && formats != NULL) {
                for (i = 0; i < formatslen; i++) {
                        if (formats[i] == *comp_id)
                                break;
                }
                if (i == formatslen)
                        return (0);
        }

        /*
         * Check curve list if present, otherwise everything is supported.
         */
        tls1_get_curvelist(s, 1, &curves, &curveslen);
        if (curve_id != NULL && curves != NULL) {
                for (i = 0; i < curveslen; i++) {
                        if (curves[i] == *curve_id)
                                break;
                }
                if (i == curveslen)
                        return (0);
        }

        return (1);
}

/* Check EC server key is compatible with client extensions. */
int
tls1_check_ec_server_key(SSL *s)
{
        CERT_PKEY *cpk = s->cert->pkeys + SSL_PKEY_ECC;
        uint16_t curve_id;
        uint8_t comp_id;
        EVP_PKEY *pkey;
        int rv;

        if (cpk->x509 == NULL || cpk->privatekey == NULL)
                return (0);
        if ((pkey = X509_get_pubkey(cpk->x509)) == NULL)
                return (0);
        rv = tls1_set_ec_id(&curve_id, &comp_id, pkey->pkey.ec);
        EVP_PKEY_free(pkey);
        if (rv != 1)
                return (0);

        return tls1_check_ec_key(s, &curve_id, &comp_id);
}

/* Check EC temporary key is compatible with client extensions. */
int
tls1_check_ec_tmp_key(SSL *s)
{
        EC_KEY *ec = s->cert->ecdh_tmp;
        uint16_t curve_id;

        /* Need a shared curve. */
        if (tls1_get_shared_curve(s) != NID_undef)
                return (1);

        if (ec == NULL)
                return (0);

        if (tls1_set_ec_id(&curve_id, NULL, ec) != 1)
                return (0);

        return tls1_check_ec_key(s, &curve_id, NULL);
}

/*
 * List of supported signature algorithms and hashes. Should make this
 * customisable at some point, for now include everything we support.
 */

static unsigned char tls12_sigalgs[] = {
        TLSEXT_hash_sha512, TLSEXT_signature_rsa,
        TLSEXT_hash_sha512, TLSEXT_signature_ecdsa,
#ifndef OPENSSL_NO_GOST
        TLSEXT_hash_streebog_512, TLSEXT_signature_gostr12_512,
#endif

        TLSEXT_hash_sha384, TLSEXT_signature_rsa,
        TLSEXT_hash_sha384, TLSEXT_signature_ecdsa,

        TLSEXT_hash_sha256, TLSEXT_signature_rsa,
        TLSEXT_hash_sha256, TLSEXT_signature_ecdsa,

#ifndef OPENSSL_NO_GOST
        TLSEXT_hash_streebog_256, TLSEXT_signature_gostr12_256,
        TLSEXT_hash_gost94, TLSEXT_signature_gostr01,
#endif

        TLSEXT_hash_sha224, TLSEXT_signature_rsa,
        TLSEXT_hash_sha224, TLSEXT_signature_ecdsa,

        TLSEXT_hash_sha1, TLSEXT_signature_rsa,
        TLSEXT_hash_sha1, TLSEXT_signature_ecdsa,
};

void
tls12_get_req_sig_algs(SSL *s, unsigned char **sigalgs, size_t *sigalgs_len)
{
        *sigalgs = tls12_sigalgs;
        *sigalgs_len = sizeof(tls12_sigalgs);
}

int
ssl_check_clienthello_tlsext_early(SSL *s)
{
        int ret = SSL_TLSEXT_ERR_NOACK;
        int al = SSL_AD_UNRECOGNIZED_NAME;

        /* The handling of the ECPointFormats extension is done elsewhere, namely in
         * ssl3_choose_cipher in s3_lib.c.
         */
        /* The handling of the EllipticCurves extension is done elsewhere, namely in
         * ssl3_choose_cipher in s3_lib.c.
         */

        if (s->ctx != NULL && s->ctx->internal->tlsext_servername_callback != 0)
                ret = s->ctx->internal->tlsext_servername_callback(s, &al,
                    s->ctx->internal->tlsext_servername_arg);
        else if (s->initial_ctx != NULL && s->initial_ctx->internal->tlsext_servername_callback != 0)
                ret = s->initial_ctx->internal->tlsext_servername_callback(s, &al,
                    s->initial_ctx->internal->tlsext_servername_arg);

        switch (ret) {
        case SSL_TLSEXT_ERR_ALERT_FATAL:
                ssl3_send_alert(s, SSL3_AL_FATAL, al);
                return -1;
        case SSL_TLSEXT_ERR_ALERT_WARNING:
                ssl3_send_alert(s, SSL3_AL_WARNING, al);
                return 1;
        case SSL_TLSEXT_ERR_NOACK:
                s->internal->servername_done = 0;
        default:
                return 1;
        }
}

int
ssl_check_clienthello_tlsext_late(SSL *s)
{
        int ret = SSL_TLSEXT_ERR_OK;
        int al = 0;     /* XXX gcc3 */

        /* If status request then ask callback what to do.
         * Note: this must be called after servername callbacks in case
         * the certificate has changed, and must be called after the cipher
         * has been chosen because this may influence which certificate is sent
         */
        if ((s->tlsext_status_type != -1) &&
            s->ctx && s->ctx->internal->tlsext_status_cb) {
                int r;
                CERT_PKEY *certpkey;
                certpkey = ssl_get_server_send_pkey(s);
                /* If no certificate can't return certificate status */
                if (certpkey == NULL) {
                        s->internal->tlsext_status_expected = 0;
                        return 1;
                }
                /* Set current certificate to one we will use so
                 * SSL_get_certificate et al can pick it up.
                 */
                s->cert->key = certpkey;
                r = s->ctx->internal->tlsext_status_cb(s,
                    s->ctx->internal->tlsext_status_arg);
                switch (r) {
                        /* We don't want to send a status request response */
                case SSL_TLSEXT_ERR_NOACK:
                        s->internal->tlsext_status_expected = 0;
                        break;
                        /* status request response should be sent */
                case SSL_TLSEXT_ERR_OK:
                        if (s->internal->tlsext_ocsp_resp)
                                s->internal->tlsext_status_expected = 1;
                        else
                                s->internal->tlsext_status_expected = 0;
                        break;
                        /* something bad happened */
                case SSL_TLSEXT_ERR_ALERT_FATAL:
                        ret = SSL_TLSEXT_ERR_ALERT_FATAL;
                        al = SSL_AD_INTERNAL_ERROR;
                        goto err;
                }
        } else
                s->internal->tlsext_status_expected = 0;

err:
        switch (ret) {
        case SSL_TLSEXT_ERR_ALERT_FATAL:
                ssl3_send_alert(s, SSL3_AL_FATAL, al);
                return -1;
        case SSL_TLSEXT_ERR_ALERT_WARNING:
                ssl3_send_alert(s, SSL3_AL_WARNING, al);
                return 1;
        default:
                return 1;
        }
}

int
ssl_check_serverhello_tlsext(SSL *s)
{
        int ret = SSL_TLSEXT_ERR_NOACK;
        int al = SSL_AD_UNRECOGNIZED_NAME;

        ret = SSL_TLSEXT_ERR_OK;

        if (s->ctx != NULL && s->ctx->internal->tlsext_servername_callback != 0)
                ret = s->ctx->internal->tlsext_servername_callback(s, &al,
                    s->ctx->internal->tlsext_servername_arg);
        else if (s->initial_ctx != NULL && s->initial_ctx->internal->tlsext_servername_callback != 0)
                ret = s->initial_ctx->internal->tlsext_servername_callback(s, &al,
                    s->initial_ctx->internal->tlsext_servername_arg);

        /* If we've requested certificate status and we wont get one
         * tell the callback
         */
        if ((s->tlsext_status_type != -1) && !(s->internal->tlsext_status_expected) &&
            s->ctx && s->ctx->internal->tlsext_status_cb) {
                int r;
                /* Set resp to NULL, resplen to -1 so callback knows
                 * there is no response.
                 */
                free(s->internal->tlsext_ocsp_resp);
                s->internal->tlsext_ocsp_resp = NULL;
                s->internal->tlsext_ocsp_resplen = -1;
                r = s->ctx->internal->tlsext_status_cb(s,
                    s->ctx->internal->tlsext_status_arg);
                if (r == 0) {
                        al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
                        ret = SSL_TLSEXT_ERR_ALERT_FATAL;
                }
                if (r < 0) {
                        al = SSL_AD_INTERNAL_ERROR;
                        ret = SSL_TLSEXT_ERR_ALERT_FATAL;
                }
        }

        switch (ret) {
        case SSL_TLSEXT_ERR_ALERT_FATAL:
                ssl3_send_alert(s, SSL3_AL_FATAL, al);

                return -1;
        case SSL_TLSEXT_ERR_ALERT_WARNING:
                ssl3_send_alert(s, SSL3_AL_WARNING, al);

                return 1;
        case SSL_TLSEXT_ERR_NOACK:
                s->internal->servername_done = 0;
        default:
                return 1;
        }
}

/* Since the server cache lookup is done early on in the processing of the
 * ClientHello, and other operations depend on the result, we need to handle
 * any TLS session ticket extension at the same time.
 *
 *   session_id: points at the session ID in the ClientHello.
 *   session_id_len: the length of the session ID.
 *   ext_block: a CBS for the ClientHello extensions block.
 *   ret: (output) on return, if a ticket was decrypted, then this is set to
 *       point to the resulting session.
 *
 * If s->internal->tls_session_secret_cb is set then we are expecting a pre-shared key
 * ciphersuite, in which case we have no use for session tickets and one will
 * never be decrypted, nor will s->internal->tlsext_ticket_expected be set to 1.
 *
 * Returns:
 *   -1: fatal error, either from parsing or decrypting the ticket.
 *    0: no ticket was found (or was ignored, based on settings).
 *    1: a zero length extension was found, indicating that the client supports
 *       session tickets but doesn't currently have one to offer.
 *    2: either s->internal->tls_session_secret_cb was set, or a ticket was offered but
 *       couldn't be decrypted because of a non-fatal error.
 *    3: a ticket was successfully decrypted and *ret was set.
 *
 * Side effects:
 *   Sets s->internal->tlsext_ticket_expected to 1 if the server will have to issue
 *   a new session ticket to the client because the client indicated support
 *   (and s->internal->tls_session_secret_cb is NULL) but the client either doesn't have
 *   a session ticket or we couldn't use the one it gave us, or if
 *   s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
 *   Otherwise, s->internal->tlsext_ticket_expected is set to 0.
 */
int
tls1_process_ticket(SSL *s, const unsigned char *session_id, int session_id_len,
    CBS *ext_block, SSL_SESSION **ret)
{
        CBS extensions;

        s->internal->tlsext_ticket_expected = 0;
        *ret = NULL;

        /*
         * If tickets disabled behave as if no ticket present to permit stateful
         * resumption.
         */
        if (SSL_get_options(s) & SSL_OP_NO_TICKET)
                return 0;

        /*
         * An empty extensions block is valid, but obviously does not contain
         * a session ticket.
         */
        if (CBS_len(ext_block) == 0)
                return 0;

        if (!CBS_get_u16_length_prefixed(ext_block, &extensions))
                return -1;

        while (CBS_len(&extensions) > 0) {
                uint16_t ext_type;
                CBS ext_data;

                if (!CBS_get_u16(&extensions, &ext_type) ||
                    !CBS_get_u16_length_prefixed(&extensions, &ext_data))
                        return -1;

                if (ext_type == TLSEXT_TYPE_session_ticket) {
                        int r;
                        if (CBS_len(&ext_data) == 0) {
                                /* The client will accept a ticket but doesn't
                                 * currently have one. */
                                s->internal->tlsext_ticket_expected = 1;
                                return 1;
                        }
                        if (s->internal->tls_session_secret_cb != NULL) {
                                /* Indicate that the ticket couldn't be
                                 * decrypted rather than generating the session
                                 * from ticket now, trigger abbreviated
                                 * handshake based on external mechanism to
                                 * calculate the master secret later. */
                                return 2;
                        }

                        r = tls_decrypt_ticket(s, CBS_data(&ext_data),
                            CBS_len(&ext_data), session_id, session_id_len, ret);

                        switch (r) {
                        case 2: /* ticket couldn't be decrypted */
                                s->internal->tlsext_ticket_expected = 1;
                                return 2;
                        case 3: /* ticket was decrypted */
                                return r;
                        case 4: /* ticket decrypted but need to renew */
                                s->internal->tlsext_ticket_expected = 1;
                                return 3;
                        default: /* fatal error */
                                return -1;
                        }
                }
        }
        return 0;
}

/* tls_decrypt_ticket attempts to decrypt a session ticket.
 *
 *   etick: points to the body of the session ticket extension.
 *   eticklen: the length of the session tickets extenion.
 *   sess_id: points at the session ID.
 *   sesslen: the length of the session ID.
 *   psess: (output) on return, if a ticket was decrypted, then this is set to
 *       point to the resulting session.
 *
 * Returns:
 *   -1: fatal error, either from parsing or decrypting the ticket.
 *    2: the ticket couldn't be decrypted.
 *    3: a ticket was successfully decrypted and *psess was set.
 *    4: same as 3, but the ticket needs to be renewed.
 */
static int
tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
    const unsigned char *sess_id, int sesslen, SSL_SESSION **psess)
{
        SSL_SESSION *sess;
        unsigned char *sdec;
        const unsigned char *p;
        int slen, mlen, renew_ticket = 0;
        unsigned char tick_hmac[EVP_MAX_MD_SIZE];
        HMAC_CTX hctx;
        EVP_CIPHER_CTX ctx;
        SSL_CTX *tctx = s->initial_ctx;

        /*
         * The API guarantees EVP_MAX_IV_LENGTH bytes of space for
         * the iv to tlsext_ticket_key_cb().  Since the total space
         * required for a session cookie is never less than this,
         * this check isn't too strict.  The exact check comes later.
         */
        if (eticklen < 16 + EVP_MAX_IV_LENGTH)
                return 2;

        /* Initialize session ticket encryption and HMAC contexts */
        HMAC_CTX_init(&hctx);
        EVP_CIPHER_CTX_init(&ctx);
        if (tctx->internal->tlsext_ticket_key_cb) {
                unsigned char *nctick = (unsigned char *)etick;
                int rv = tctx->internal->tlsext_ticket_key_cb(s,
                    nctick, nctick + 16, &ctx, &hctx, 0);
                if (rv < 0) {
                        HMAC_CTX_cleanup(&hctx);
                        EVP_CIPHER_CTX_cleanup(&ctx);
                        return -1;
                }
                if (rv == 0) {
                        HMAC_CTX_cleanup(&hctx);
                        EVP_CIPHER_CTX_cleanup(&ctx);
                        return 2;
                }
                if (rv == 2)
                        renew_ticket = 1;
        } else {
                /* Check key name matches */
                if (timingsafe_memcmp(etick,
                    tctx->internal->tlsext_tick_key_name, 16))
                        return 2;
                HMAC_Init_ex(&hctx, tctx->internal->tlsext_tick_hmac_key,
                    16, tlsext_tick_md(), NULL);
                EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
                    tctx->internal->tlsext_tick_aes_key, etick + 16);
        }

        /*
         * Attempt to process session ticket, first conduct sanity and
         * integrity checks on ticket.
         */
        mlen = HMAC_size(&hctx);
        if (mlen < 0) {
                HMAC_CTX_cleanup(&hctx);
                EVP_CIPHER_CTX_cleanup(&ctx);
                return -1;
        }

        /* Sanity check ticket length: must exceed keyname + IV + HMAC */
        if (eticklen <= 16 + EVP_CIPHER_CTX_iv_length(&ctx) + mlen) {
                HMAC_CTX_cleanup(&hctx);
                EVP_CIPHER_CTX_cleanup(&ctx);
                return 2;
        }
        eticklen -= mlen;

        /* Check HMAC of encrypted ticket */
        if (HMAC_Update(&hctx, etick, eticklen) <= 0 ||
            HMAC_Final(&hctx, tick_hmac, NULL) <= 0) {
                HMAC_CTX_cleanup(&hctx);
                EVP_CIPHER_CTX_cleanup(&ctx);
                return -1;
        }

        HMAC_CTX_cleanup(&hctx);
        if (timingsafe_memcmp(tick_hmac, etick + eticklen, mlen)) {
                EVP_CIPHER_CTX_cleanup(&ctx);
                return 2;
        }

        /* Attempt to decrypt session data */
        /* Move p after IV to start of encrypted ticket, update length */
        p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
        eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
        sdec = malloc(eticklen);
        if (sdec == NULL ||
            EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen) <= 0) {
                free(sdec);
                EVP_CIPHER_CTX_cleanup(&ctx);
                return -1;
        }
        if (EVP_DecryptFinal_ex(&ctx, sdec + slen, &mlen) <= 0) {
                free(sdec);
                EVP_CIPHER_CTX_cleanup(&ctx);
                return 2;
        }
        slen += mlen;
        EVP_CIPHER_CTX_cleanup(&ctx);
        p = sdec;

        sess = d2i_SSL_SESSION(NULL, &p, slen);
        free(sdec);
        if (sess) {
                /* The session ID, if non-empty, is used by some clients to
                 * detect that the ticket has been accepted. So we copy it to
                 * the session structure. If it is empty set length to zero
                 * as required by standard.
                 */
                if (sesslen)
                        memcpy(sess->session_id, sess_id, sesslen);
                sess->session_id_length = sesslen;
                *psess = sess;
                if (renew_ticket)
                        return 4;
                else
                        return 3;
        }
        ERR_clear_error();
        /* For session parse failure, indicate that we need to send a new
         * ticket. */
        return 2;
}

/* Tables to translate from NIDs to TLS v1.2 ids */

typedef struct {
        int nid;
        int id;
} tls12_lookup;

static tls12_lookup tls12_md[] = {
        {NID_md5, TLSEXT_hash_md5},
        {NID_sha1, TLSEXT_hash_sha1},
        {NID_sha224, TLSEXT_hash_sha224},
        {NID_sha256, TLSEXT_hash_sha256},
        {NID_sha384, TLSEXT_hash_sha384},
        {NID_sha512, TLSEXT_hash_sha512},
        {NID_id_GostR3411_94, TLSEXT_hash_gost94},
        {NID_id_tc26_gost3411_2012_256, TLSEXT_hash_streebog_256},
        {NID_id_tc26_gost3411_2012_512, TLSEXT_hash_streebog_512}
};

static tls12_lookup tls12_sig[] = {
        {EVP_PKEY_RSA, TLSEXT_signature_rsa},
        {EVP_PKEY_EC, TLSEXT_signature_ecdsa},
        {EVP_PKEY_GOSTR01, TLSEXT_signature_gostr01},
};

static int
tls12_find_id(int nid, tls12_lookup *table, size_t tlen)
{
        size_t i;
        for (i = 0; i < tlen; i++) {
                if (table[i].nid == nid)
                        return table[i].id;
        }
        return -1;
}

int
tls12_get_hashid(const EVP_MD *md)
{
        if (md == NULL)
                return -1;

        return tls12_find_id(EVP_MD_type(md), tls12_md,
            sizeof(tls12_md) / sizeof(tls12_lookup));
}

int
tls12_get_sigid(const EVP_PKEY *pk)
{
        if (pk == NULL)
                return -1;

        return tls12_find_id(pk->type, tls12_sig,
            sizeof(tls12_sig) / sizeof(tls12_lookup));
}

int
tls12_get_hashandsig(CBB *cbb, const EVP_PKEY *pk, const EVP_MD *md)
{
        int hash_id, sig_id;

        if ((hash_id = tls12_get_hashid(md)) == -1)
                return 0;
        if ((sig_id = tls12_get_sigid(pk)) == -1)
                return 0;

        if (!CBB_add_u8(cbb, hash_id))
                return 0;
        if (!CBB_add_u8(cbb, sig_id))
                return 0;

        return 1;
}

const EVP_MD *
tls12_get_hash(unsigned char hash_alg)
{
        switch (hash_alg) {
        case TLSEXT_hash_sha1:
                return EVP_sha1();
        case TLSEXT_hash_sha224:
                return EVP_sha224();
        case TLSEXT_hash_sha256:
                return EVP_sha256();
        case TLSEXT_hash_sha384:
                return EVP_sha384();
        case TLSEXT_hash_sha512:
                return EVP_sha512();
#ifndef OPENSSL_NO_GOST
        case TLSEXT_hash_gost94:
                return EVP_gostr341194();
        case TLSEXT_hash_streebog_256:
                return EVP_streebog256();
        case TLSEXT_hash_streebog_512:
                return EVP_streebog512();
#endif
        default:
                return NULL;
        }
}

/* Set preferred digest for each key type */

int
tls1_process_sigalgs(SSL *s, CBS *cbs)
{
        const EVP_MD *md;
        CERT *c = s->cert;
        int idx;

        /* Extension ignored for inappropriate versions */
        if (!SSL_USE_SIGALGS(s))
                return 1;

        /* Should never happen */
        if (c == NULL)
                return 0;

        c->pkeys[SSL_PKEY_RSA_SIGN].digest = NULL;
        c->pkeys[SSL_PKEY_RSA_ENC].digest = NULL;
        c->pkeys[SSL_PKEY_ECC].digest = NULL;
        c->pkeys[SSL_PKEY_GOST01].digest = NULL;

        while (CBS_len(cbs) > 0) {
                uint8_t hash_alg, sig_alg;

                if (!CBS_get_u8(cbs, &hash_alg) || !CBS_get_u8(cbs, &sig_alg))
                        return 0;

                switch (sig_alg) {
                case TLSEXT_signature_rsa:
                        idx = SSL_PKEY_RSA_SIGN;
                        break;
                case TLSEXT_signature_ecdsa:
                        idx = SSL_PKEY_ECC;
                        break;
                case TLSEXT_signature_gostr01:
                case TLSEXT_signature_gostr12_256:
                case TLSEXT_signature_gostr12_512:
                        idx = SSL_PKEY_GOST01;
                        break;
                default:
                        continue;
                }

                if (c->pkeys[idx].digest == NULL) {
                        md = tls12_get_hash(hash_alg);
                        if (md) {
                                c->pkeys[idx].digest = md;
                                if (idx == SSL_PKEY_RSA_SIGN)
                                        c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
                        }
                }

        }

        /*
         * Set any remaining keys to default values. NOTE: if alg is not
         * supported it stays as NULL.
         */
        if (!c->pkeys[SSL_PKEY_RSA_SIGN].digest) {
                c->pkeys[SSL_PKEY_RSA_SIGN].digest = EVP_sha1();
                c->pkeys[SSL_PKEY_RSA_ENC].digest = EVP_sha1();
        }
        if (!c->pkeys[SSL_PKEY_ECC].digest)
                c->pkeys[SSL_PKEY_ECC].digest = EVP_sha1();
#ifndef OPENSSL_NO_GOST
        if (!c->pkeys[SSL_PKEY_GOST01].digest)
                c->pkeys[SSL_PKEY_GOST01].digest = EVP_gostr341194();
#endif
        return 1;
}