If cipher list contains a match for an explicit ciphersuite only match that

[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 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.
 */
/* ====================================================================
 * Copyright 2005 Nokia. All rights reserved.
 *
 * The portions of the attached software ("Contribution") is developed by
 * Nokia Corporation and is licensed pursuant to the OpenSSL open source
 * license.
 *
 * The Contribution, originally written by Mika Kousa and Pasi Eronen of
 * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
 * support (see RFC 4279) to OpenSSL.
 *
 * No patent licenses or other rights except those expressly stated in
 * the OpenSSL open source license shall be deemed granted or received
 * expressly, by implication, estoppel, or otherwise.
 *
 * No assurances are provided by Nokia that the Contribution does not
 * infringe the patent or other intellectual property rights of any third
 * party or that the license provides you with all the necessary rights
 * to make use of the Contribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
 * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
 * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
 * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
 * OTHERWISE.
 */

#include <stdio.h>
#include <openssl/objects.h>
#include <openssl/comp.h>
#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_NUM_IDX         9

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. */
        {0,SSL_TXT_ALL, 0,SSL_ALL & ~SSL_eNULL & ~SSL_kECDH & ~SSL_kECDHE, SSL_ALL ,0,0,0,SSL_ALL,SSL_ALL}, /* must be first */
        /* TODO: COMPLEMENT OF ALL and COMPLEMENT OF DEFAULT do not have ECC cipher suites handled properly. */
        {0,SSL_TXT_CMPALL,0,SSL_eNULL,0,0,0,0,SSL_ENC_MASK,0},  /* COMPLEMENT OF ALL */
        {0,SSL_TXT_CMPDEF,0,SSL_ADH, 0,0,0,0,SSL_AUTH_MASK,0},
        {0,SSL_TXT_kKRB5,0,SSL_kKRB5,0,0,0,0,SSL_MKEY_MASK,0},  /* VRS Kerberos5 */
        {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_kPSK,0,SSL_kPSK,  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},
        {0,SSL_TXT_aKRB5,0,SSL_aKRB5,0,0,0,0,SSL_AUTH_MASK,0},  /* VRS Kerberos5 */
        {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_aPSK,0,SSL_aPSK,  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_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_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_PSK, 0,SSL_PSK,   0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_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},
        };

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_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)
        {
        if (ssl_comp_methods != NULL)
                return;

        CRYPTO_w_lock(CRYPTO_LOCK_SSL);
        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);
                                        }
                                }
                        }
                MemCheck_on();
                }
        CRYPTO_w_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;
        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;
        }

static unsigned long ssl_cipher_get_disabled(void)
        {
        unsigned long mask;

        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 OPENSSL_NO_PSK
        mask |= SSL_kPSK;
#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_AES128_IDX] == NULL) ? SSL_AES: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;

        return(mask);
        }

static void ssl_cipher_collect_ciphers(const SSL_METHOD *ssl_method,
                int num_of_ciphers, unsigned long mask, 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);
                /* drop those that use any of that is not available */
                if ((c != NULL) && c->valid && !(c->algorithms & mask))
                        {
                        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 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 that one only */

                if (cipher_id)
                        {
                        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)
                                {
                                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, 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, *start, *buf;
        int j, multi, found, rule, retval, ok, buflen;
        unsigned long cipher_id;
        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;

                start=l;
                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;
                         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 */

                        if (ca_list[j]->valid)
                                {
                                cipher_id = ca_list[j]->id;
                                break;
                                }

                        /* 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;

                        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, 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;
        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.
         */
        disabled_mask = ssl_cipher_get_disabled();

        /*
         * 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,
                                   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,
                                   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)
                {
                if (curr->active)
                        {
                        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;
        sk_SSL_CIPHER_set_cmp_func(*cipher_list_by_id,ssl_cipher_ptr_id_cmp);

        return(cipherstack);
        }

char *SSL_CIPHER_description(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,alg_s;
#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;
        alg_s=cipher->algo_strength;
        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;
        case SSL_kPSK:
                kx="PSK";
                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;
        case SSL_aPSK:
                au="PSK";
                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;
        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))
                {
                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