[thirdparty/openssl.git] / ssl / ssl_ciph.c

/* ssl/ssl_ciph.c */
/* 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) 1998-2006 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).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * ECC cipher suite support in OpenSSL originally developed by
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */
#include <stdio.h>
#include <openssl/objects.h>
#ifndef OPENSSL_NO_COMP
# include <openssl/comp.h>
#endif

#include "ssl_locl.h"

#define SSL_ENC_DES_IDX         0
#define SSL_ENC_3DES_IDX        1
#define SSL_ENC_RC4_IDX         2
#define SSL_ENC_RC2_IDX         3
#define SSL_ENC_IDEA_IDX        4
#define SSL_ENC_eFZA_IDX        5
#define SSL_ENC_NULL_IDX        6
#define SSL_ENC_AES128_IDX      7
#define SSL_ENC_AES256_IDX      8
#define SSL_ENC_CAMELLIA128_IDX 9
#define SSL_ENC_CAMELLIA256_IDX 10
#define SSL_ENC_SEED_IDX        11
#define SSL_ENC_NUM_IDX         12

static const EVP_CIPHER *ssl_cipher_methods[SSL_ENC_NUM_IDX] = {
    NULL, NULL, NULL, NULL, NULL, NULL,
};

#define SSL_COMP_NULL_IDX       0
#define SSL_COMP_ZLIB_IDX       1
#define SSL_COMP_NUM_IDX        2

static STACK_OF(SSL_COMP) *ssl_comp_methods = NULL;

#define SSL_MD_MD5_IDX  0
#define SSL_MD_SHA1_IDX 1
#define SSL_MD_NUM_IDX  2
static const EVP_MD *ssl_digest_methods[SSL_MD_NUM_IDX] = {
    NULL, NULL,
};

#define CIPHER_ADD      1
#define CIPHER_KILL     2
#define CIPHER_DEL      3
#define CIPHER_ORD      4
#define CIPHER_SPECIAL  5

typedef struct cipher_order_st {
    SSL_CIPHER *cipher;
    int active;
    int dead;
    struct cipher_order_st *next, *prev;
} CIPHER_ORDER;

static const SSL_CIPHER cipher_aliases[] = {
    /* Don't include eNULL unless specifically enabled. */
    /*
     * Don't include ECC in ALL because these ciphers are not yet official.
     */
    /* must be first */
    {0, SSL_TXT_ALL, 0, SSL_ALL & ~SSL_eNULL & ~SSL_kECDH & ~SSL_kECDHE,
     SSL_ALL, 0, 0, 0, SSL_ALL, SSL_ALL},
    /*
     * TODO: COMPLEMENT OF ALL and COMPLEMENT OF DEFAULT do not have ECC
     * cipher suites handled properly.
     */
    /* COMPLEMENT OF ALL */
    {0, SSL_TXT_CMPALL, 0, SSL_eNULL, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_CMPDEF, 0, SSL_ADH, 0, 0, 0, 0, SSL_AUTH_MASK, 0},
    /* VRS Kerberos5 */
    {0, SSL_TXT_kKRB5, 0, SSL_kKRB5, 0, 0, 0, 0, SSL_MKEY_MASK, 0},
    {0, SSL_TXT_kRSA, 0, SSL_kRSA, 0, 0, 0, 0, SSL_MKEY_MASK, 0},
    {0, SSL_TXT_kDHr, 0, SSL_kDHr, 0, 0, 0, 0, SSL_MKEY_MASK, 0},
    {0, SSL_TXT_kDHd, 0, SSL_kDHd, 0, 0, 0, 0, SSL_MKEY_MASK, 0},
    {0, SSL_TXT_kEDH, 0, SSL_kEDH, 0, 0, 0, 0, SSL_MKEY_MASK, 0},
    {0, SSL_TXT_kFZA, 0, SSL_kFZA, 0, 0, 0, 0, SSL_MKEY_MASK, 0},
    {0, SSL_TXT_DH, 0, SSL_DH, 0, 0, 0, 0, SSL_MKEY_MASK, 0},
    {0, SSL_TXT_ECC, 0, (SSL_kECDH | SSL_kECDHE), 0, 0, 0, 0, SSL_MKEY_MASK,
     0},
    {0, SSL_TXT_EDH, 0, SSL_EDH, 0, 0, 0, 0, SSL_MKEY_MASK | SSL_AUTH_MASK,
     0},
    /* VRS Kerberos5 */
    {0, SSL_TXT_aKRB5, 0, SSL_aKRB5, 0, 0, 0, 0, SSL_AUTH_MASK, 0},
    {0, SSL_TXT_aRSA, 0, SSL_aRSA, 0, 0, 0, 0, SSL_AUTH_MASK, 0},
    {0, SSL_TXT_aDSS, 0, SSL_aDSS, 0, 0, 0, 0, SSL_AUTH_MASK, 0},
    {0, SSL_TXT_aFZA, 0, SSL_aFZA, 0, 0, 0, 0, SSL_AUTH_MASK, 0},
    {0, SSL_TXT_aNULL, 0, SSL_aNULL, 0, 0, 0, 0, SSL_AUTH_MASK, 0},
    {0, SSL_TXT_aDH, 0, SSL_aDH, 0, 0, 0, 0, SSL_AUTH_MASK, 0},
    {0, SSL_TXT_DSS, 0, SSL_DSS, 0, 0, 0, 0, SSL_AUTH_MASK, 0},

    {0, SSL_TXT_DES, 0, SSL_DES, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_3DES, 0, SSL_3DES, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_RC4, 0, SSL_RC4, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_RC2, 0, SSL_RC2, 0, 0, 0, 0, SSL_ENC_MASK, 0},
#ifndef OPENSSL_NO_IDEA
    {0, SSL_TXT_IDEA, 0, SSL_IDEA, 0, 0, 0, 0, SSL_ENC_MASK, 0},
#endif
    {0, SSL_TXT_SEED, 0, SSL_SEED, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_eNULL, 0, SSL_eNULL, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_eFZA, 0, SSL_eFZA, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_AES, 0, SSL_AES, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_CAMELLIA, 0, SSL_CAMELLIA, 0, 0, 0, 0, SSL_ENC_MASK, 0},

    {0, SSL_TXT_MD5, 0, SSL_MD5, 0, 0, 0, 0, SSL_MAC_MASK, 0},
    {0, SSL_TXT_SHA1, 0, SSL_SHA1, 0, 0, 0, 0, SSL_MAC_MASK, 0},
    {0, SSL_TXT_SHA, 0, SSL_SHA, 0, 0, 0, 0, SSL_MAC_MASK, 0},

    {0, SSL_TXT_NULL, 0, SSL_NULL, 0, 0, 0, 0, SSL_ENC_MASK, 0},
    {0, SSL_TXT_KRB5, 0, SSL_KRB5, 0, 0, 0, 0, SSL_AUTH_MASK | SSL_MKEY_MASK,
     0},
    {0, SSL_TXT_RSA, 0, SSL_RSA, 0, 0, 0, 0, SSL_AUTH_MASK | SSL_MKEY_MASK,
     0},
    {0, SSL_TXT_ADH, 0, SSL_ADH, 0, 0, 0, 0, SSL_AUTH_MASK | SSL_MKEY_MASK,
     0},
    {0, SSL_TXT_FZA, 0, SSL_FZA, 0, 0, 0, 0,
     SSL_AUTH_MASK | SSL_MKEY_MASK | SSL_ENC_MASK, 0},

    {0, SSL_TXT_SSLV2, 0, SSL_SSLV2, 0, 0, 0, 0, SSL_SSL_MASK, 0},
    {0, SSL_TXT_SSLV3, 0, SSL_SSLV3, 0, 0, 0, 0, SSL_SSL_MASK, 0},
    {0, SSL_TXT_TLSV1, 0, SSL_TLSV1, 0, 0, 0, 0, SSL_SSL_MASK, 0},

    {0, SSL_TXT_EXP, 0, 0, SSL_EXPORT, 0, 0, 0, 0, SSL_EXP_MASK},
    {0, SSL_TXT_EXPORT, 0, 0, SSL_EXPORT, 0, 0, 0, 0, SSL_EXP_MASK},
    {0, SSL_TXT_EXP40, 0, 0, SSL_EXP40, 0, 0, 0, 0, SSL_STRONG_MASK},
    {0, SSL_TXT_EXP56, 0, 0, SSL_EXP56, 0, 0, 0, 0, SSL_STRONG_MASK},
    {0, SSL_TXT_LOW, 0, 0, SSL_LOW, 0, 0, 0, 0, SSL_STRONG_MASK},
    {0, SSL_TXT_MEDIUM, 0, 0, SSL_MEDIUM, 0, 0, 0, 0, SSL_STRONG_MASK},
    {0, SSL_TXT_HIGH, 0, 0, SSL_HIGH, 0, 0, 0, 0, SSL_STRONG_MASK},
    {0, SSL_TXT_FIPS, 0, 0, SSL_FIPS, 0, 0, 0, 0, SSL_FIPS | SSL_STRONG_NONE},
};

void ssl_load_ciphers(void)
{
    ssl_cipher_methods[SSL_ENC_DES_IDX] = EVP_get_cipherbyname(SN_des_cbc);
    ssl_cipher_methods[SSL_ENC_3DES_IDX] =
        EVP_get_cipherbyname(SN_des_ede3_cbc);
    ssl_cipher_methods[SSL_ENC_RC4_IDX] = EVP_get_cipherbyname(SN_rc4);
    ssl_cipher_methods[SSL_ENC_RC2_IDX] = EVP_get_cipherbyname(SN_rc2_cbc);
#ifndef OPENSSL_NO_IDEA
    ssl_cipher_methods[SSL_ENC_IDEA_IDX] = EVP_get_cipherbyname(SN_idea_cbc);
#else
    ssl_cipher_methods[SSL_ENC_IDEA_IDX] = NULL;
#endif
    ssl_cipher_methods[SSL_ENC_AES128_IDX] =
        EVP_get_cipherbyname(SN_aes_128_cbc);
    ssl_cipher_methods[SSL_ENC_AES256_IDX] =
        EVP_get_cipherbyname(SN_aes_256_cbc);
    ssl_cipher_methods[SSL_ENC_CAMELLIA128_IDX] =
        EVP_get_cipherbyname(SN_camellia_128_cbc);
    ssl_cipher_methods[SSL_ENC_CAMELLIA256_IDX] =
        EVP_get_cipherbyname(SN_camellia_256_cbc);
    ssl_cipher_methods[SSL_ENC_SEED_IDX] = EVP_get_cipherbyname(SN_seed_cbc);

    ssl_digest_methods[SSL_MD_MD5_IDX] = EVP_get_digestbyname(SN_md5);
    ssl_digest_methods[SSL_MD_SHA1_IDX] = EVP_get_digestbyname(SN_sha1);
}

#ifndef OPENSSL_NO_COMP

static int sk_comp_cmp(const SSL_COMP *const *a, const SSL_COMP *const *b)
{
    return ((*a)->id - (*b)->id);
}

static void load_builtin_compressions(void)
{
    int got_write_lock = 0;

    CRYPTO_r_lock(CRYPTO_LOCK_SSL);
    if (ssl_comp_methods == NULL) {
        CRYPTO_r_unlock(CRYPTO_LOCK_SSL);
        CRYPTO_w_lock(CRYPTO_LOCK_SSL);
        got_write_lock = 1;

        if (ssl_comp_methods == NULL) {
            SSL_COMP *comp = NULL;

            MemCheck_off();
            ssl_comp_methods = sk_SSL_COMP_new(sk_comp_cmp);
            if (ssl_comp_methods != NULL) {
                comp = (SSL_COMP *)OPENSSL_malloc(sizeof(SSL_COMP));
                if (comp != NULL) {
                    comp->method = COMP_zlib();
                    if (comp->method && comp->method->type == NID_undef)
                        OPENSSL_free(comp);
                    else {
                        comp->id = SSL_COMP_ZLIB_IDX;
                        comp->name = comp->method->name;
                        sk_SSL_COMP_push(ssl_comp_methods, comp);
                    }
                }
                sk_SSL_COMP_sort(ssl_comp_methods);
            }
            MemCheck_on();
        }
    }

    if (got_write_lock)
        CRYPTO_w_unlock(CRYPTO_LOCK_SSL);
    else
        CRYPTO_r_unlock(CRYPTO_LOCK_SSL);
}
#endif

int ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc,
                       const EVP_MD **md, SSL_COMP **comp)
{
    int i;
    SSL_CIPHER *c;

    c = s->cipher;
    if (c == NULL)
        return (0);
    if (comp != NULL) {
        SSL_COMP ctmp;
#ifndef OPENSSL_NO_COMP
        load_builtin_compressions();
#endif

        *comp = NULL;
        ctmp.id = s->compress_meth;
        if (ssl_comp_methods != NULL) {
            i = sk_SSL_COMP_find(ssl_comp_methods, &ctmp);
            if (i >= 0)
                *comp = sk_SSL_COMP_value(ssl_comp_methods, i);
            else
                *comp = NULL;
        }
    }

    if ((enc == NULL) || (md == NULL))
        return (0);

    switch (c->algorithms & SSL_ENC_MASK) {
    case SSL_DES:
        i = SSL_ENC_DES_IDX;
        break;
    case SSL_3DES:
        i = SSL_ENC_3DES_IDX;
        break;
    case SSL_RC4:
        i = SSL_ENC_RC4_IDX;
        break;
    case SSL_RC2:
        i = SSL_ENC_RC2_IDX;
        break;
    case SSL_IDEA:
        i = SSL_ENC_IDEA_IDX;
        break;
    case SSL_eNULL:
        i = SSL_ENC_NULL_IDX;
        break;
    case SSL_AES:
        switch (c->alg_bits) {
        case 128:
            i = SSL_ENC_AES128_IDX;
            break;
        case 256:
            i = SSL_ENC_AES256_IDX;
            break;
        default:
            i = -1;
            break;
        }
        break;
    case SSL_CAMELLIA:
        switch (c->alg_bits) {
        case 128:
            i = SSL_ENC_CAMELLIA128_IDX;
            break;
        case 256:
            i = SSL_ENC_CAMELLIA256_IDX;
            break;
        default:
            i = -1;
            break;
        }
        break;
    case SSL_SEED:
        i = SSL_ENC_SEED_IDX;
        break;

    default:
        i = -1;
        break;
    }

    if ((i < 0) || (i >= SSL_ENC_NUM_IDX))
        *enc = NULL;
    else {
        if (i == SSL_ENC_NULL_IDX)
            *enc = EVP_enc_null();
        else
            *enc = ssl_cipher_methods[i];
    }

    switch (c->algorithms & SSL_MAC_MASK) {
    case SSL_MD5:
        i = SSL_MD_MD5_IDX;
        break;
    case SSL_SHA1:
        i = SSL_MD_SHA1_IDX;
        break;
    default:
        i = -1;
        break;
    }
    if ((i < 0) || (i >= SSL_MD_NUM_IDX))
        *md = NULL;
    else
        *md = ssl_digest_methods[i];

    if ((*enc != NULL) && (*md != NULL))
        return (1);
    else
        return (0);
}

#define ITEM_SEP(a) \
        (((a) == ':') || ((a) == ' ') || ((a) == ';') || ((a) == ','))

static void ll_append_tail(CIPHER_ORDER **head, CIPHER_ORDER *curr,
                           CIPHER_ORDER **tail)
{
    if (curr == *tail)
        return;
    if (curr == *head)
        *head = curr->next;
    if (curr->prev != NULL)
        curr->prev->next = curr->next;
    if (curr->next != NULL)     /* should always be true */
        curr->next->prev = curr->prev;
    (*tail)->next = curr;
    curr->prev = *tail;
    curr->next = NULL;
    *tail = curr;
}

struct disabled_masks {         /* This is a kludge no longer needed with
                                 * OpenSSL 0.9.9, where 128-bit and 256-bit
                                 * algorithms simply will get separate bits. */
    unsigned long mask;         /* everything except m256 */
    unsigned long m256;         /* applies to 256-bit algorithms only */
};

static struct disabled_masks ssl_cipher_get_disabled(void)
{
    unsigned long mask;
    unsigned long m256;
    struct disabled_masks ret;

    mask = SSL_kFZA;
#ifdef OPENSSL_NO_RSA
    mask |= SSL_aRSA | SSL_kRSA;
#endif
#ifdef OPENSSL_NO_DSA
    mask |= SSL_aDSS;
#endif
#ifdef OPENSSL_NO_DH
    mask |= SSL_kDHr | SSL_kDHd | SSL_kEDH | SSL_aDH;
#endif
#ifdef OPENSSL_NO_KRB5
    mask |= SSL_kKRB5 | SSL_aKRB5;
#endif
#ifdef OPENSSL_NO_ECDH
    mask |= SSL_kECDH | SSL_kECDHE;
#endif
#ifdef SSL_FORBID_ENULL
    mask |= SSL_eNULL;
#endif

    mask |= (ssl_cipher_methods[SSL_ENC_DES_IDX] == NULL) ? SSL_DES : 0;
    mask |= (ssl_cipher_methods[SSL_ENC_3DES_IDX] == NULL) ? SSL_3DES : 0;
    mask |= (ssl_cipher_methods[SSL_ENC_RC4_IDX] == NULL) ? SSL_RC4 : 0;
    mask |= (ssl_cipher_methods[SSL_ENC_RC2_IDX] == NULL) ? SSL_RC2 : 0;
    mask |= (ssl_cipher_methods[SSL_ENC_IDEA_IDX] == NULL) ? SSL_IDEA : 0;
    mask |= (ssl_cipher_methods[SSL_ENC_eFZA_IDX] == NULL) ? SSL_eFZA : 0;
    mask |= (ssl_cipher_methods[SSL_ENC_SEED_IDX] == NULL) ? SSL_SEED : 0;

    mask |= (ssl_digest_methods[SSL_MD_MD5_IDX] == NULL) ? SSL_MD5 : 0;
    mask |= (ssl_digest_methods[SSL_MD_SHA1_IDX] == NULL) ? SSL_SHA1 : 0;

    /* finally consider algorithms where mask and m256 differ */
    m256 = mask;
    mask |= (ssl_cipher_methods[SSL_ENC_AES128_IDX] == NULL) ? SSL_AES : 0;
    mask |=
        (ssl_cipher_methods[SSL_ENC_CAMELLIA128_IDX] ==
         NULL) ? SSL_CAMELLIA : 0;
    m256 |= (ssl_cipher_methods[SSL_ENC_AES256_IDX] == NULL) ? SSL_AES : 0;
    m256 |=
        (ssl_cipher_methods[SSL_ENC_CAMELLIA256_IDX] ==
         NULL) ? SSL_CAMELLIA : 0;

    ret.mask = mask;
    ret.m256 = m256;
    return ret;
}

static void ssl_cipher_collect_ciphers(const SSL_METHOD *ssl_method,
                                       int num_of_ciphers, unsigned long mask,
                                       unsigned long m256,
                                       CIPHER_ORDER *co_list,
                                       CIPHER_ORDER **head_p,
                                       CIPHER_ORDER **tail_p)
{
    int i, co_list_num;
    SSL_CIPHER *c;

    /*
     * We have num_of_ciphers descriptions compiled in, depending on the
     * method selected (SSLv2 and/or SSLv3, TLSv1 etc).
     * These will later be sorted in a linked list with at most num
     * entries.
     */

    /* Get the initial list of ciphers */
    co_list_num = 0;            /* actual count of ciphers */
    for (i = 0; i < num_of_ciphers; i++) {
        c = ssl_method->get_cipher(i);
#define IS_MASKED(c) ((c)->algorithms & (((c)->alg_bits == 256) ? m256 : mask))
        /* drop those that use any of that is not available */
#ifdef OPENSSL_FIPS
        if ((c != NULL) && c->valid && !IS_MASKED(c)
            && (!FIPS_mode() || (c->algo_strength & SSL_FIPS)))
#else
        if ((c != NULL) && c->valid && !IS_MASKED(c))
#endif
        {
            co_list[co_list_num].cipher = c;
            co_list[co_list_num].next = NULL;
            co_list[co_list_num].prev = NULL;
            co_list[co_list_num].active = 0;
            co_list_num++;
#ifdef KSSL_DEBUG
            printf("\t%d: %s %lx %lx\n", i, c->name, c->id, c->algorithms);
#endif                          /* KSSL_DEBUG */
            /*
             * if (!sk_push(ca_list,(char *)c)) goto err;
             */
        }
    }

    /*
     * Prepare linked list from list entries
     */
    for (i = 1; i < co_list_num - 1; i++) {
        co_list[i].prev = &(co_list[i - 1]);
        co_list[i].next = &(co_list[i + 1]);
    }
    if (co_list_num > 0) {
        (*head_p) = &(co_list[0]);
        (*head_p)->prev = NULL;
        (*head_p)->next = &(co_list[1]);
        (*tail_p) = &(co_list[co_list_num - 1]);
        (*tail_p)->prev = &(co_list[co_list_num - 2]);
        (*tail_p)->next = NULL;
    }
}

static void ssl_cipher_collect_aliases(SSL_CIPHER **ca_list,
                                       int num_of_group_aliases,
                                       unsigned long mask, CIPHER_ORDER *head)
{
    CIPHER_ORDER *ciph_curr;
    SSL_CIPHER **ca_curr;
    int i;

    /*
     * First, add the real ciphers as already collected
     */
    ciph_curr = head;
    ca_curr = ca_list;
    while (ciph_curr != NULL) {
        *ca_curr = ciph_curr->cipher;
        ca_curr++;
        ciph_curr = ciph_curr->next;
    }

    /*
     * Now we add the available ones from the cipher_aliases[] table.
     * They represent either an algorithm, that must be fully
     * supported (not match any bit in mask) or represent a cipher
     * strength value (will be added in any case because algorithms=0).
     */
    for (i = 0; i < num_of_group_aliases; i++) {
        if ((i == 0) ||         /* always fetch "ALL" */
            !(cipher_aliases[i].algorithms & mask)) {
            *ca_curr = (SSL_CIPHER *)(cipher_aliases + i);
            ca_curr++;
        }
    }

    *ca_curr = NULL;            /* end of list */
}

static void ssl_cipher_apply_rule(unsigned long cipher_id,
                                  unsigned long ssl_version,
                                  unsigned long algorithms,
                                  unsigned long mask,
                                  unsigned long algo_strength,
                                  unsigned long mask_strength, int rule,
                                  int strength_bits, CIPHER_ORDER *co_list,
                                  CIPHER_ORDER **head_p,
                                  CIPHER_ORDER **tail_p)
{
    CIPHER_ORDER *head, *tail, *curr, *curr2, *tail2;
    SSL_CIPHER *cp;
    unsigned long ma, ma_s;

#ifdef CIPHER_DEBUG
    printf("Applying rule %d with %08lx %08lx %08lx %08lx (%d)\n",
           rule, algorithms, mask, algo_strength, mask_strength,
           strength_bits);
#endif

    curr = head = *head_p;
    curr2 = head;
    tail2 = tail = *tail_p;
    for (;;) {
        if ((curr == NULL) || (curr == tail2))
            break;
        curr = curr2;
        curr2 = curr->next;

        cp = curr->cipher;

        /*
         * If explicit cipher suite, match only that one for its own protocol
         * version. Usual selection criteria will be used for similar
         * ciphersuites from other version!
         */

        if (cipher_id && (cp->algorithms & SSL_SSL_MASK) == ssl_version) {
            if (cp->id != cipher_id)
                continue;
        }

        /*
         * Selection criteria is either the number of strength_bits
         * or the algorithm used.
         */
        else if (strength_bits == -1) {
            ma = mask & cp->algorithms;
            ma_s = mask_strength & cp->algo_strength;

#ifdef CIPHER_DEBUG
            printf
                ("\nName: %s:\nAlgo = %08lx Algo_strength = %08lx\nMask = %08lx Mask_strength %08lx\n",
                 cp->name, cp->algorithms, cp->algo_strength, mask,
                 mask_strength);
            printf("ma = %08lx ma_s %08lx, ma&algo=%08lx, ma_s&algos=%08lx\n",
                   ma, ma_s, ma & algorithms, ma_s & algo_strength);
#endif
            /*
             * Select: if none of the mask bit was met from the
             * cipher or not all of the bits were met, the
             * selection does not apply.
             */
            if (((ma == 0) && (ma_s == 0)) ||
                ((ma & algorithms) != ma) || ((ma_s & algo_strength) != ma_s))
                continue;       /* does not apply */
        } else if (strength_bits != cp->strength_bits)
            continue;           /* does not apply */

#ifdef CIPHER_DEBUG
        printf("Action = %d\n", rule);
#endif

        /* add the cipher if it has not been added yet. */
        if (rule == CIPHER_ADD) {
            if (!curr->active) {
                int add_this_cipher = 1;

                if (((cp->algorithms & (SSL_kECDHE | SSL_kECDH | SSL_aECDSA))
                     != 0)) {
                    /*
                     * Make sure "ECCdraft" ciphersuites are activated only
                     * if *explicitly* requested, but not implicitly (such as
                     * as part of the "AES" alias).
                     */

                    add_this_cipher =
                        (mask & (SSL_kECDHE | SSL_kECDH | SSL_aECDSA)) != 0
                        || cipher_id != 0;
                }

                if (add_this_cipher) {
                    ll_append_tail(&head, curr, &tail);
                    curr->active = 1;
                }
            }
        }
        /* Move the added cipher to this location */
        else if (rule == CIPHER_ORD) {
            if (curr->active) {
                ll_append_tail(&head, curr, &tail);
            }
        } else if (rule == CIPHER_DEL)
            curr->active = 0;
        else if (rule == CIPHER_KILL) {
            if (head == curr)
                head = curr->next;
            else
                curr->prev->next = curr->next;
            if (tail == curr)
                tail = curr->prev;
            curr->active = 0;
            if (curr->next != NULL)
                curr->next->prev = curr->prev;
            if (curr->prev != NULL)
                curr->prev->next = curr->next;
            curr->next = NULL;
            curr->prev = NULL;
        }
    }

    *head_p = head;
    *tail_p = tail;
}

static int ssl_cipher_strength_sort(CIPHER_ORDER *co_list,
                                    CIPHER_ORDER **head_p,
                                    CIPHER_ORDER **tail_p)
{
    int max_strength_bits, i, *number_uses;
    CIPHER_ORDER *curr;

    /*
     * This routine sorts the ciphers with descending strength. The sorting
     * must keep the pre-sorted sequence, so we apply the normal sorting
     * routine as '+' movement to the end of the list.
     */
    max_strength_bits = 0;
    curr = *head_p;
    while (curr != NULL) {
        if (curr->active && (curr->cipher->strength_bits > max_strength_bits))
            max_strength_bits = curr->cipher->strength_bits;
        curr = curr->next;
    }

    number_uses = OPENSSL_malloc((max_strength_bits + 1) * sizeof(int));
    if (!number_uses) {
        SSLerr(SSL_F_SSL_CIPHER_STRENGTH_SORT, ERR_R_MALLOC_FAILURE);
        return (0);
    }
    memset(number_uses, 0, (max_strength_bits + 1) * sizeof(int));

    /*
     * Now find the strength_bits values actually used
     */
    curr = *head_p;
    while (curr != NULL) {
        if (curr->active)
            number_uses[curr->cipher->strength_bits]++;
        curr = curr->next;
    }
    /*
     * Go through the list of used strength_bits values in descending
     * order.
     */
    for (i = max_strength_bits; i >= 0; i--)
        if (number_uses[i] > 0)
            ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, CIPHER_ORD, i,
                                  co_list, head_p, tail_p);

    OPENSSL_free(number_uses);
    return (1);
}

static int ssl_cipher_process_rulestr(const char *rule_str,
                                      CIPHER_ORDER *co_list,
                                      CIPHER_ORDER **head_p,
                                      CIPHER_ORDER **tail_p,
                                      SSL_CIPHER **ca_list)
{
    unsigned long algorithms, mask, algo_strength, mask_strength;
    const char *l, *buf;
    int j, multi, found, rule, retval, ok, buflen;
    unsigned long cipher_id = 0, ssl_version = 0;
    char ch;

    retval = 1;
    l = rule_str;
    for (;;) {
        ch = *l;

        if (ch == '\0')
            break;              /* done */
        if (ch == '-') {
            rule = CIPHER_DEL;
            l++;
        } else if (ch == '+') {
            rule = CIPHER_ORD;
            l++;
        } else if (ch == '!') {
            rule = CIPHER_KILL;
            l++;
        } else if (ch == '@') {
            rule = CIPHER_SPECIAL;
            l++;
        } else {
            rule = CIPHER_ADD;
        }

        if (ITEM_SEP(ch)) {
            l++;
            continue;
        }

        algorithms = mask = algo_strength = mask_strength = 0;

        for (;;) {
            ch = *l;
            buf = l;
            buflen = 0;
#ifndef CHARSET_EBCDIC
            while (((ch >= 'A') && (ch <= 'Z')) ||
                   ((ch >= '0') && (ch <= '9')) ||
                   ((ch >= 'a') && (ch <= 'z')) || (ch == '-'))
#else
            while (isalnum(ch) || (ch == '-'))
#endif
            {
                ch = *(++l);
                buflen++;
            }

            if (buflen == 0) {
                /*
                 * We hit something we cannot deal with,
                 * it is no command or separator nor
                 * alphanumeric, so we call this an error.
                 */
                SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR,
                       SSL_R_INVALID_COMMAND);
                retval = found = 0;
                l++;
                break;
            }

            if (rule == CIPHER_SPECIAL) {
                found = 0;      /* unused -- avoid compiler warning */
                break;          /* special treatment */
            }

            /* check for multi-part specification */
            if (ch == '+') {
                multi = 1;
                l++;
            } else
                multi = 0;

            /*
             * Now search for the cipher alias in the ca_list. Be careful
             * with the strncmp, because the "buflen" limitation
             * will make the rule "ADH:SOME" and the cipher
             * "ADH-MY-CIPHER" look like a match for buflen=3.
             * So additionally check whether the cipher name found
             * has the correct length. We can save a strlen() call:
             * just checking for the '\0' at the right place is
             * sufficient, we have to strncmp() anyway. (We cannot
             * use strcmp(), because buf is not '\0' terminated.)
             */
            j = found = 0;
            cipher_id = 0;
            ssl_version = 0;
            while (ca_list[j]) {
                if (!strncmp(buf, ca_list[j]->name, buflen) &&
                    (ca_list[j]->name[buflen] == '\0')) {
                    found = 1;
                    break;
                } else
                    j++;
            }
            if (!found)
                break;          /* ignore this entry */

                        /*-
                         * New algorithms:
                         *  1 - any old restrictions apply outside new mask
                         *  2 - any new restrictions apply outside old mask
                         *  3 - enforce old & new where masks intersect
                         */
            algorithms = (algorithms & ~ca_list[j]->mask) | /* 1 */
                (ca_list[j]->algorithms & ~mask) | /* 2 */
                (algorithms & ca_list[j]->algorithms); /* 3 */
            mask |= ca_list[j]->mask;
            algo_strength = (algo_strength & ~ca_list[j]->mask_strength) |
                (ca_list[j]->algo_strength & ~mask_strength) |
                (algo_strength & ca_list[j]->algo_strength);
            mask_strength |= ca_list[j]->mask_strength;

            /* explicit ciphersuite found */
            if (ca_list[j]->valid) {
                cipher_id = ca_list[j]->id;
                ssl_version = ca_list[j]->algorithms & SSL_SSL_MASK;
                break;
            }

            if (!multi)
                break;
        }

        /*
         * Ok, we have the rule, now apply it
         */
        if (rule == CIPHER_SPECIAL) { /* special command */
            ok = 0;
            if ((buflen == 8) && !strncmp(buf, "STRENGTH", 8))
                ok = ssl_cipher_strength_sort(co_list, head_p, tail_p);
            else
                SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR,
                       SSL_R_INVALID_COMMAND);
            if (ok == 0)
                retval = 0;
            /*
             * We do not support any "multi" options
             * together with "@", so throw away the
             * rest of the command, if any left, until
             * end or ':' is found.
             */
            while ((*l != '\0') && !ITEM_SEP(*l))
                l++;
        } else if (found) {
            ssl_cipher_apply_rule(cipher_id, ssl_version, algorithms, mask,
                                  algo_strength, mask_strength, rule, -1,
                                  co_list, head_p, tail_p);
        } else {
            while ((*l != '\0') && !ITEM_SEP(*l))
                l++;
        }
        if (*l == '\0')
            break;              /* done */
    }

    return (retval);
}

STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, STACK_OF(SSL_CIPHER)
                                             **cipher_list, STACK_OF(SSL_CIPHER)
                                             **cipher_list_by_id,
                                             const char *rule_str)
{
    int ok, num_of_ciphers, num_of_alias_max, num_of_group_aliases;
    unsigned long disabled_mask;
    unsigned long disabled_m256;
    STACK_OF(SSL_CIPHER) *cipherstack, *tmp_cipher_list;
    const char *rule_p;
    CIPHER_ORDER *co_list = NULL, *head = NULL, *tail = NULL, *curr;
    SSL_CIPHER **ca_list = NULL;

    /*
     * Return with error if nothing to do.
     */
    if (rule_str == NULL || cipher_list == NULL || cipher_list_by_id == NULL)
        return NULL;

    /*
     * To reduce the work to do we only want to process the compiled
     * in algorithms, so we first get the mask of disabled ciphers.
     */
    {
        struct disabled_masks d;
        d = ssl_cipher_get_disabled();
        disabled_mask = d.mask;
        disabled_m256 = d.m256;
    }

    /*
     * Now we have to collect the available ciphers from the compiled
     * in ciphers. We cannot get more than the number compiled in, so
     * it is used for allocation.
     */
    num_of_ciphers = ssl_method->num_ciphers();
#ifdef KSSL_DEBUG
    printf("ssl_create_cipher_list() for %d ciphers\n", num_of_ciphers);
#endif                          /* KSSL_DEBUG */
    co_list =
        (CIPHER_ORDER *)OPENSSL_malloc(sizeof(CIPHER_ORDER) * num_of_ciphers);
    if (co_list == NULL) {
        SSLerr(SSL_F_SSL_CREATE_CIPHER_LIST, ERR_R_MALLOC_FAILURE);
        return (NULL);          /* Failure */
    }

    ssl_cipher_collect_ciphers(ssl_method, num_of_ciphers, disabled_mask,
                               disabled_m256, co_list, &head, &tail);

    /*
     * We also need cipher aliases for selecting based on the rule_str.
     * There might be two types of entries in the rule_str: 1) names
     * of ciphers themselves 2) aliases for groups of ciphers.
     * For 1) we need the available ciphers and for 2) the cipher
     * groups of cipher_aliases added together in one list (otherwise
     * we would be happy with just the cipher_aliases table).
     */
    num_of_group_aliases = sizeof(cipher_aliases) / sizeof(SSL_CIPHER);
    num_of_alias_max = num_of_ciphers + num_of_group_aliases + 1;
    ca_list =
        (SSL_CIPHER **)OPENSSL_malloc(sizeof(SSL_CIPHER *) *
                                      num_of_alias_max);
    if (ca_list == NULL) {
        OPENSSL_free(co_list);
        SSLerr(SSL_F_SSL_CREATE_CIPHER_LIST, ERR_R_MALLOC_FAILURE);
        return (NULL);          /* Failure */
    }
    ssl_cipher_collect_aliases(ca_list, num_of_group_aliases,
                               (disabled_mask & disabled_m256), head);

    /*
     * If the rule_string begins with DEFAULT, apply the default rule
     * before using the (possibly available) additional rules.
     */
    ok = 1;
    rule_p = rule_str;
    if (strncmp(rule_str, "DEFAULT", 7) == 0) {
        ok = ssl_cipher_process_rulestr(SSL_DEFAULT_CIPHER_LIST,
                                        co_list, &head, &tail, ca_list);
        rule_p += 7;
        if (*rule_p == ':')
            rule_p++;
    }

    if (ok && (strlen(rule_p) > 0))
        ok = ssl_cipher_process_rulestr(rule_p, co_list, &head, &tail,
                                        ca_list);

    OPENSSL_free(ca_list);      /* Not needed anymore */

    if (!ok) {                  /* Rule processing failure */
        OPENSSL_free(co_list);
        return (NULL);
    }
    /*
     * Allocate new "cipherstack" for the result, return with error
     * if we cannot get one.
     */
    if ((cipherstack = sk_SSL_CIPHER_new_null()) == NULL) {
        OPENSSL_free(co_list);
        return (NULL);
    }

    /*
     * The cipher selection for the list is done. The ciphers are added
     * to the resulting precedence to the STACK_OF(SSL_CIPHER).
     */
    for (curr = head; curr != NULL; curr = curr->next) {
#ifdef OPENSSL_FIPS
        if (curr->active
            && (!FIPS_mode() || curr->cipher->algo_strength & SSL_FIPS))
#else
        if (curr->active)
#endif
        {
            sk_SSL_CIPHER_push(cipherstack, curr->cipher);
#ifdef CIPHER_DEBUG
            printf("<%s>\n", curr->cipher->name);
#endif
        }
    }
    OPENSSL_free(co_list);      /* Not needed any longer */

    tmp_cipher_list = sk_SSL_CIPHER_dup(cipherstack);
    if (tmp_cipher_list == NULL) {
        sk_SSL_CIPHER_free(cipherstack);
        return NULL;
    }
    if (*cipher_list != NULL)
        sk_SSL_CIPHER_free(*cipher_list);
    *cipher_list = cipherstack;
    if (*cipher_list_by_id != NULL)
        sk_SSL_CIPHER_free(*cipher_list_by_id);
    *cipher_list_by_id = tmp_cipher_list;
    (void)sk_SSL_CIPHER_set_cmp_func(*cipher_list_by_id,
                                     ssl_cipher_ptr_id_cmp);

    sk_SSL_CIPHER_sort(*cipher_list_by_id);
    return (cipherstack);
}

char *SSL_CIPHER_description(const SSL_CIPHER *cipher, char *buf, int len)
{
    int is_export, pkl, kl;
    const char *ver, *exp_str;
    const char *kx, *au, *enc, *mac;
    unsigned long alg, alg2;
#ifdef KSSL_DEBUG
    static const char *format =
        "%-23s %s Kx=%-8s Au=%-4s Enc=%-9s Mac=%-4s%s AL=%lx\n";
#else
    static const char *format =
        "%-23s %s Kx=%-8s Au=%-4s Enc=%-9s Mac=%-4s%s\n";
#endif                          /* KSSL_DEBUG */

    alg = cipher->algorithms;
    alg2 = cipher->algorithm2;

    is_export = SSL_C_IS_EXPORT(cipher);
    pkl = SSL_C_EXPORT_PKEYLENGTH(cipher);
    kl = SSL_C_EXPORT_KEYLENGTH(cipher);
    exp_str = is_export ? " export" : "";

    if (alg & SSL_SSLV2)
        ver = "SSLv2";
    else if (alg & SSL_SSLV3)
        ver = "SSLv3";
    else
        ver = "unknown";

    switch (alg & SSL_MKEY_MASK) {
    case SSL_kRSA:
        kx = is_export ? (pkl == 512 ? "RSA(512)" : "RSA(1024)") : "RSA";
        break;
    case SSL_kDHr:
        kx = "DH/RSA";
        break;
    case SSL_kDHd:
        kx = "DH/DSS";
        break;
    case SSL_kKRB5:            /* VRS */
    case SSL_KRB5:             /* VRS */
        kx = "KRB5";
        break;
    case SSL_kFZA:
        kx = "Fortezza";
        break;
    case SSL_kEDH:
        kx = is_export ? (pkl == 512 ? "DH(512)" : "DH(1024)") : "DH";
        break;
    case SSL_kECDH:
    case SSL_kECDHE:
        kx = is_export ? "ECDH(<=163)" : "ECDH";
        break;
    default:
        kx = "unknown";
    }

    switch (alg & SSL_AUTH_MASK) {
    case SSL_aRSA:
        au = "RSA";
        break;
    case SSL_aDSS:
        au = "DSS";
        break;
    case SSL_aDH:
        au = "DH";
        break;
    case SSL_aKRB5:            /* VRS */
    case SSL_KRB5:             /* VRS */
        au = "KRB5";
        break;
    case SSL_aFZA:
    case SSL_aNULL:
        au = "None";
        break;
    case SSL_aECDSA:
        au = "ECDSA";
        break;
    default:
        au = "unknown";
        break;
    }

    switch (alg & SSL_ENC_MASK) {
    case SSL_DES:
        enc = (is_export && kl == 5) ? "DES(40)" : "DES(56)";
        break;
    case SSL_3DES:
        enc = "3DES(168)";
        break;
    case SSL_RC4:
        enc = is_export ? (kl == 5 ? "RC4(40)" : "RC4(56)")
            : ((alg2 & SSL2_CF_8_BYTE_ENC) ? "RC4(64)" : "RC4(128)");
        break;
    case SSL_RC2:
        enc = is_export ? (kl == 5 ? "RC2(40)" : "RC2(56)") : "RC2(128)";
        break;
    case SSL_IDEA:
        enc = "IDEA(128)";
        break;
    case SSL_eFZA:
        enc = "Fortezza";
        break;
    case SSL_eNULL:
        enc = "None";
        break;
    case SSL_AES:
        switch (cipher->strength_bits) {
        case 128:
            enc = "AES(128)";
            break;
        case 192:
            enc = "AES(192)";
            break;
        case 256:
            enc = "AES(256)";
            break;
        default:
            enc = "AES(?" "?" "?)";
            break;
        }
        break;
    case SSL_CAMELLIA:
        switch (cipher->strength_bits) {
        case 128:
            enc = "Camellia(128)";
            break;
        case 256:
            enc = "Camellia(256)";
            break;
        default:
            enc = "Camellia(?" "?" "?)";
            break;
        }
        break;
    case SSL_SEED:
        enc = "SEED(128)";
        break;

    default:
        enc = "unknown";
        break;
    }

    switch (alg & SSL_MAC_MASK) {
    case SSL_MD5:
        mac = "MD5";
        break;
    case SSL_SHA1:
        mac = "SHA1";
        break;
    default:
        mac = "unknown";
        break;
    }

    if (buf == NULL) {
        len = 128;
        buf = OPENSSL_malloc(len);
        if (buf == NULL)
            return ("OPENSSL_malloc Error");
    } else if (len < 128)
        return ("Buffer too small");

#ifdef KSSL_DEBUG
    BIO_snprintf(buf, len, format, cipher->name, ver, kx, au, enc, mac,
                 exp_str, alg);
#else
    BIO_snprintf(buf, len, format, cipher->name, ver, kx, au, enc, mac,
                 exp_str);
#endif                          /* KSSL_DEBUG */
    return (buf);
}

char *SSL_CIPHER_get_version(const SSL_CIPHER *c)
{
    int i;

    if (c == NULL)
        return ("(NONE)");
    i = (int)(c->id >> 24L);
    if (i == 3)
        return ("TLSv1/SSLv3");
    else if (i == 2)
        return ("SSLv2");
    else
        return ("unknown");
}

/* return the actual cipher being used */
const char *SSL_CIPHER_get_name(const SSL_CIPHER *c)
{
    if (c != NULL)
        return (c->name);
    return ("(NONE)");
}

/* number of bits for symmetric cipher */
int SSL_CIPHER_get_bits(const SSL_CIPHER *c, int *alg_bits)
{
    int ret = 0;

    if (c != NULL) {
        if (alg_bits != NULL)
            *alg_bits = c->alg_bits;
        ret = c->strength_bits;
    }
    return (ret);
}

SSL_COMP *ssl3_comp_find(STACK_OF(SSL_COMP) *sk, int n)
{
    SSL_COMP *ctmp;
    int i, nn;

    if ((n == 0) || (sk == NULL))
        return (NULL);
    nn = sk_SSL_COMP_num(sk);
    for (i = 0; i < nn; i++) {
        ctmp = sk_SSL_COMP_value(sk, i);
        if (ctmp->id == n)
            return (ctmp);
    }
    return (NULL);
}

#ifdef OPENSSL_NO_COMP
void *SSL_COMP_get_compression_methods(void)
{
    return NULL;
}

int SSL_COMP_add_compression_method(int id, void *cm)
{
    return 1;
}

const char *SSL_COMP_get_name(const void *comp)
{
    return NULL;
}
#else
STACK_OF(SSL_COMP) *SSL_COMP_get_compression_methods(void)
{
    load_builtin_compressions();
    return (ssl_comp_methods);
}

int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm)
{
    SSL_COMP *comp;

    if (cm == NULL || cm->type == NID_undef)
        return 1;

        /*-
         * According to draft-ietf-tls-compression-04.txt, the
         * compression number ranges should be the following:
         *
         *   0 to  63:  methods defined by the IETF
         *  64 to 192:  external party methods assigned by IANA
         * 193 to 255:  reserved for private use
         */
    if (id < 193 || id > 255) {
        SSLerr(SSL_F_SSL_COMP_ADD_COMPRESSION_METHOD,
               SSL_R_COMPRESSION_ID_NOT_WITHIN_PRIVATE_RANGE);
        return 0;
    }

    MemCheck_off();
    comp = (SSL_COMP *)OPENSSL_malloc(sizeof(SSL_COMP));
    comp->id = id;
    comp->method = cm;
    load_builtin_compressions();
    if (ssl_comp_methods && sk_SSL_COMP_find(ssl_comp_methods, comp) >= 0) {
        OPENSSL_free(comp);
        MemCheck_on();
        SSLerr(SSL_F_SSL_COMP_ADD_COMPRESSION_METHOD,
               SSL_R_DUPLICATE_COMPRESSION_ID);
        return (1);
    } else if ((ssl_comp_methods == NULL)
               || !sk_SSL_COMP_push(ssl_comp_methods, comp)) {
        OPENSSL_free(comp);
        MemCheck_on();
        SSLerr(SSL_F_SSL_COMP_ADD_COMPRESSION_METHOD, ERR_R_MALLOC_FAILURE);
        return (1);
    } else {
        MemCheck_on();
        return (0);
    }
}

const char *SSL_COMP_get_name(const COMP_METHOD *comp)
{
    if (comp)
        return comp->name;
    return NULL;
}

#endif