ssl/ssl_ciph.c

   1 /* ssl/ssl_ciph.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58 /* ====================================================================
  59  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
  60  * ECC cipher suite support in OpenSSL originally developed by
  61  * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
  62  */
  63 #include <stdio.h>
  64 #include <openssl/objects.h>
  65 #include <openssl/comp.h>
  66 #include "ssl_locl.h"
  67
  68 #define SSL_ENC_DES_IDX         0
  69 #define SSL_ENC_3DES_IDX        1
  70 #define SSL_ENC_RC4_IDX         2
  71 #define SSL_ENC_RC2_IDX         3
  72 #define SSL_ENC_IDEA_IDX        4
  73 #define SSL_ENC_eFZA_IDX        5
  74 #define SSL_ENC_NULL_IDX        6
  75 #define SSL_ENC_AES128_IDX      7
  76 #define SSL_ENC_AES256_IDX      8
  77 #define SSL_ENC_NUM_IDX         9
  78
  79 static const EVP_CIPHER *ssl_cipher_methods[SSL_ENC_NUM_IDX]={
  80         NULL,NULL,NULL,NULL,NULL,NULL,
  81         };
  82
  83 #define SSL_COMP_NULL_IDX       0
  84 #define SSL_COMP_ZLIB_IDX       1
  85 #define SSL_COMP_NUM_IDX        2
  86
  87 static STACK_OF(SSL_COMP) *ssl_comp_methods=NULL;
  88
  89 #define SSL_MD_MD5_IDX  0
  90 #define SSL_MD_SHA1_IDX 1
  91 #define SSL_MD_NUM_IDX  2
  92 static const EVP_MD *ssl_digest_methods[SSL_MD_NUM_IDX]={
  93         NULL,NULL,
  94         };
  95
  96 #define CIPHER_ADD      1
  97 #define CIPHER_KILL     2
  98 #define CIPHER_DEL      3
  99 #define CIPHER_ORD      4
 100 #define CIPHER_SPECIAL  5
 101
 102 typedef struct cipher_order_st
 103         {
 104         SSL_CIPHER *cipher;
 105         int active;
 106         int dead;
 107         struct cipher_order_st *next,*prev;
 108         } CIPHER_ORDER;
 109
 110 static const SSL_CIPHER cipher_aliases[]={
 111         /* Don't include eNULL unless specifically enabled. */
 112         /* Don't include ECC in ALL because these ciphers are not yet official. */
 113         {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 */
 114         /* TODO: COMPLEMENT OF ALL and COMPLEMENT OF DEFAULT do not have ECC cipher suites handled properly. */
 115         {0,SSL_TXT_CMPALL,0,SSL_eNULL,0,0,0,0,SSL_ENC_MASK,0},  /* COMPLEMENT OF ALL */
 116         {0,SSL_TXT_CMPDEF,0,SSL_ADH, 0,0,0,0,SSL_AUTH_MASK,0},
 117         {0,SSL_TXT_kKRB5,0,SSL_kKRB5,0,0,0,0,SSL_MKEY_MASK,0},  /* VRS Kerberos5 */
 118         {0,SSL_TXT_kRSA,0,SSL_kRSA,  0,0,0,0,SSL_MKEY_MASK,0},
 119         {0,SSL_TXT_kDHr,0,SSL_kDHr,  0,0,0,0,SSL_MKEY_MASK,0},
 120         {0,SSL_TXT_kDHd,0,SSL_kDHd,  0,0,0,0,SSL_MKEY_MASK,0},
 121         {0,SSL_TXT_kEDH,0,SSL_kEDH,  0,0,0,0,SSL_MKEY_MASK,0},
 122         {0,SSL_TXT_kFZA,0,SSL_kFZA,  0,0,0,0,SSL_MKEY_MASK,0},
 123         {0,SSL_TXT_DH,  0,SSL_DH,    0,0,0,0,SSL_MKEY_MASK,0},
 124         {0,SSL_TXT_ECC, 0,(SSL_kECDH|SSL_kECDHE), 0,0,0,0,SSL_MKEY_MASK,0},
 125         {0,SSL_TXT_EDH, 0,SSL_EDH,   0,0,0,0,SSL_MKEY_MASK|SSL_AUTH_MASK,0},
 126         {0,SSL_TXT_aKRB5,0,SSL_aKRB5,0,0,0,0,SSL_AUTH_MASK,0},  /* VRS Kerberos5 */
 127         {0,SSL_TXT_aRSA,0,SSL_aRSA,  0,0,0,0,SSL_AUTH_MASK,0},
 128         {0,SSL_TXT_aDSS,0,SSL_aDSS,  0,0,0,0,SSL_AUTH_MASK,0},
 129         {0,SSL_TXT_aFZA,0,SSL_aFZA,  0,0,0,0,SSL_AUTH_MASK,0},
 130         {0,SSL_TXT_aNULL,0,SSL_aNULL,0,0,0,0,SSL_AUTH_MASK,0},
 131         {0,SSL_TXT_aDH, 0,SSL_aDH,   0,0,0,0,SSL_AUTH_MASK,0},
 132         {0,SSL_TXT_DSS, 0,SSL_DSS,   0,0,0,0,SSL_AUTH_MASK,0},
 133
 134         {0,SSL_TXT_DES, 0,SSL_DES,   0,0,0,0,SSL_ENC_MASK,0},
 135         {0,SSL_TXT_3DES,0,SSL_3DES,  0,0,0,0,SSL_ENC_MASK,0},
 136         {0,SSL_TXT_RC4, 0,SSL_RC4,   0,0,0,0,SSL_ENC_MASK,0},
 137         {0,SSL_TXT_RC2, 0,SSL_RC2,   0,0,0,0,SSL_ENC_MASK,0},
 138         {0,SSL_TXT_IDEA,0,SSL_IDEA,  0,0,0,0,SSL_ENC_MASK,0},
 139         {0,SSL_TXT_eNULL,0,SSL_eNULL,0,0,0,0,SSL_ENC_MASK,0},
 140         {0,SSL_TXT_eFZA,0,SSL_eFZA,  0,0,0,0,SSL_ENC_MASK,0},
 141         {0,SSL_TXT_AES, 0,SSL_AES,   0,0,0,0,SSL_ENC_MASK,0},
 142
 143         {0,SSL_TXT_MD5, 0,SSL_MD5,   0,0,0,0,SSL_MAC_MASK,0},
 144         {0,SSL_TXT_SHA1,0,SSL_SHA1,  0,0,0,0,SSL_MAC_MASK,0},
 145         {0,SSL_TXT_SHA, 0,SSL_SHA,   0,0,0,0,SSL_MAC_MASK,0},
 146
 147         {0,SSL_TXT_NULL,0,SSL_NULL,  0,0,0,0,SSL_ENC_MASK,0},
 148         {0,SSL_TXT_KRB5,0,SSL_KRB5,  0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_MASK,0},
 149         {0,SSL_TXT_RSA, 0,SSL_RSA,   0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_MASK,0},
 150         {0,SSL_TXT_ADH, 0,SSL_ADH,   0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_MASK,0},
 151         {0,SSL_TXT_FZA, 0,SSL_FZA,   0,0,0,0,SSL_AUTH_MASK|SSL_MKEY_MASK|SSL_ENC_MASK,0},
 152
 153         {0,SSL_TXT_SSLV2, 0,SSL_SSLV2, 0,0,0,0,SSL_SSL_MASK,0},
 154         {0,SSL_TXT_SSLV3, 0,SSL_SSLV3, 0,0,0,0,SSL_SSL_MASK,0},
 155         {0,SSL_TXT_TLSV1, 0,SSL_TLSV1, 0,0,0,0,SSL_SSL_MASK,0},
 156
 157         {0,SSL_TXT_EXP   ,0, 0,SSL_EXPORT, 0,0,0,0,SSL_EXP_MASK},
 158         {0,SSL_TXT_EXPORT,0, 0,SSL_EXPORT, 0,0,0,0,SSL_EXP_MASK},
 159         {0,SSL_TXT_EXP40, 0, 0, SSL_EXP40, 0,0,0,0,SSL_STRONG_MASK},
 160         {0,SSL_TXT_EXP56, 0, 0, SSL_EXP56, 0,0,0,0,SSL_STRONG_MASK},
 161         {0,SSL_TXT_LOW,   0, 0,   SSL_LOW, 0,0,0,0,SSL_STRONG_MASK},
 162         {0,SSL_TXT_MEDIUM,0, 0,SSL_MEDIUM, 0,0,0,0,SSL_STRONG_MASK},
 163         {0,SSL_TXT_HIGH,  0, 0,  SSL_HIGH, 0,0,0,0,SSL_STRONG_MASK},
 164         };
 165
 166 static int init_ciphers=1;
 167
 168 static void load_ciphers(void)
 169         {
 170         init_ciphers=0;
 171         ssl_cipher_methods[SSL_ENC_DES_IDX]=
 172                 EVP_get_cipherbyname(SN_des_cbc);
 173         ssl_cipher_methods[SSL_ENC_3DES_IDX]=
 174                 EVP_get_cipherbyname(SN_des_ede3_cbc);
 175         ssl_cipher_methods[SSL_ENC_RC4_IDX]=
 176                 EVP_get_cipherbyname(SN_rc4);
 177         ssl_cipher_methods[SSL_ENC_RC2_IDX]=
 178                 EVP_get_cipherbyname(SN_rc2_cbc);
 179         ssl_cipher_methods[SSL_ENC_IDEA_IDX]=
 180                 EVP_get_cipherbyname(SN_idea_cbc);
 181         ssl_cipher_methods[SSL_ENC_AES128_IDX]=
 182           EVP_get_cipherbyname(SN_aes_128_cbc);
 183         ssl_cipher_methods[SSL_ENC_AES256_IDX]=
 184           EVP_get_cipherbyname(SN_aes_256_cbc);
 185
 186         ssl_digest_methods[SSL_MD_MD5_IDX]=
 187                 EVP_get_digestbyname(SN_md5);
 188         ssl_digest_methods[SSL_MD_SHA1_IDX]=
 189                 EVP_get_digestbyname(SN_sha1);
 190         }
 191
 192 static int sk_comp_cmp(const SSL_COMP * const *a,
 193                         const SSL_COMP * const *b)
 194         {
 195         return((*a)->id-(*b)->id);
 196         }
 197
 198 static void load_builtin_compressions(void)
 199         {
 200         if (ssl_comp_methods != NULL)
 201                 return;
 202
 203         CRYPTO_w_lock(CRYPTO_LOCK_SSL);
 204         if (ssl_comp_methods == NULL)
 205                 {
 206                 SSL_COMP *comp = NULL;
 207
 208                 MemCheck_off();
 209                 ssl_comp_methods=sk_SSL_COMP_new(sk_comp_cmp);
 210                 if (ssl_comp_methods != NULL)
 211                         {
 212                         comp=(SSL_COMP *)OPENSSL_malloc(sizeof(SSL_COMP));
 213                         if (comp != NULL)
 214                                 {
 215                                 comp->method=COMP_zlib();
 216                                 if (comp->method
 217                                         && comp->method->type == NID_undef)
 218                                         OPENSSL_free(comp);
 219                                 else
 220                                         {
 221                                         comp->id=SSL_COMP_ZLIB_IDX;
 222                                         comp->name=comp->method->name;
 223                                         sk_SSL_COMP_push(ssl_comp_methods,comp);
 224                                         }
 225                                 }
 226                         }
 227                 MemCheck_on();
 228                 }
 229         CRYPTO_w_unlock(CRYPTO_LOCK_SSL);
 230         }
 231
 232 int ssl_cipher_get_evp(SSL_SESSION *s, const EVP_CIPHER **enc,
 233              const EVP_MD **md, SSL_COMP **comp)
 234         {
 235         int i;
 236         SSL_CIPHER *c;
 237
 238         c=s->cipher;
 239         if (c == NULL) return(0);
 240         if (comp != NULL)
 241                 {
 242                 SSL_COMP ctmp;
 243
 244                 load_builtin_compressions();
 245
 246                 *comp=NULL;
 247                 ctmp.id=s->compress_meth;
 248                 if (ssl_comp_methods != NULL)
 249                         {
 250                         i=sk_SSL_COMP_find(ssl_comp_methods,&ctmp);
 251                         if (i >= 0)
 252                                 *comp=sk_SSL_COMP_value(ssl_comp_methods,i);
 253                         else
 254                                 *comp=NULL;
 255                         }
 256                 }
 257
 258         if ((enc == NULL) || (md == NULL)) return(0);
 259
 260         switch (c->algorithms & SSL_ENC_MASK)
 261                 {
 262         case SSL_DES:
 263                 i=SSL_ENC_DES_IDX;
 264                 break;
 265         case SSL_3DES:
 266                 i=SSL_ENC_3DES_IDX;
 267                 break;
 268         case SSL_RC4:
 269                 i=SSL_ENC_RC4_IDX;
 270                 break;
 271         case SSL_RC2:
 272                 i=SSL_ENC_RC2_IDX;
 273                 break;
 274         case SSL_IDEA:
 275                 i=SSL_ENC_IDEA_IDX;
 276                 break;
 277         case SSL_eNULL:
 278                 i=SSL_ENC_NULL_IDX;
 279                 break;
 280         case SSL_AES:
 281                 switch(c->alg_bits)
 282                         {
 283                 case 128: i=SSL_ENC_AES128_IDX; break;
 284                 case 256: i=SSL_ENC_AES256_IDX; break;
 285                 default: i=-1; break;
 286                         }
 287                 break;
 288         default:
 289                 i= -1;
 290                 break;
 291                 }
 292
 293         if ((i < 0) || (i > SSL_ENC_NUM_IDX))
 294                 *enc=NULL;
 295         else
 296                 {
 297                 if (i == SSL_ENC_NULL_IDX)
 298                         *enc=EVP_enc_null();
 299                 else
 300                         *enc=ssl_cipher_methods[i];
 301                 }
 302
 303         switch (c->algorithms & SSL_MAC_MASK)
 304                 {
 305         case SSL_MD5:
 306                 i=SSL_MD_MD5_IDX;
 307                 break;
 308         case SSL_SHA1:
 309                 i=SSL_MD_SHA1_IDX;
 310                 break;
 311         default:
 312                 i= -1;
 313                 break;
 314                 }
 315         if ((i < 0) || (i > SSL_MD_NUM_IDX))
 316                 *md=NULL;
 317         else
 318                 *md=ssl_digest_methods[i];
 319
 320         if ((*enc != NULL) && (*md != NULL))
 321                 return(1);
 322         else
 323                 return(0);
 324         }
 325
 326 #define ITEM_SEP(a) \
 327         (((a) == ':') || ((a) == ' ') || ((a) == ';') || ((a) == ','))
 328
 329 static void ll_append_tail(CIPHER_ORDER **head, CIPHER_ORDER *curr,
 330              CIPHER_ORDER **tail)
 331         {
 332         if (curr == *tail) return;
 333         if (curr == *head)
 334                 *head=curr->next;
 335         if (curr->prev != NULL)
 336                 curr->prev->next=curr->next;
 337         if (curr->next != NULL) /* should always be true */
 338                 curr->next->prev=curr->prev;
 339         (*tail)->next=curr;
 340         curr->prev= *tail;
 341         curr->next=NULL;
 342         *tail=curr;
 343         }
 344
 345 static unsigned long ssl_cipher_get_disabled(void)
 346         {
 347         unsigned long mask;
 348
 349         mask = SSL_kFZA;
 350 #ifdef OPENSSL_NO_RSA
 351         mask |= SSL_aRSA|SSL_kRSA;
 352 #endif
 353 #ifdef OPENSSL_NO_DSA
 354         mask |= SSL_aDSS;
 355 #endif
 356 #ifdef OPENSSL_NO_DH
 357         mask |= SSL_kDHr|SSL_kDHd|SSL_kEDH|SSL_aDH;
 358 #endif
 359 #ifdef OPENSSL_NO_KRB5
 360         mask |= SSL_kKRB5|SSL_aKRB5;
 361 #endif
 362 #ifdef OPENSSL_NO_ECDH
 363         mask |= SSL_kECDH|SSL_kECDHE;
 364 #endif
 365 #ifdef SSL_FORBID_ENULL
 366         mask |= SSL_eNULL;
 367 #endif
 368
 369         mask |= (ssl_cipher_methods[SSL_ENC_DES_IDX ] == NULL) ? SSL_DES :0;
 370         mask |= (ssl_cipher_methods[SSL_ENC_3DES_IDX] == NULL) ? SSL_3DES:0;
 371         mask |= (ssl_cipher_methods[SSL_ENC_RC4_IDX ] == NULL) ? SSL_RC4 :0;
 372         mask |= (ssl_cipher_methods[SSL_ENC_RC2_IDX ] == NULL) ? SSL_RC2 :0;
 373         mask |= (ssl_cipher_methods[SSL_ENC_IDEA_IDX] == NULL) ? SSL_IDEA:0;
 374         mask |= (ssl_cipher_methods[SSL_ENC_eFZA_IDX] == NULL) ? SSL_eFZA:0;
 375         mask |= (ssl_cipher_methods[SSL_ENC_AES128_IDX] == NULL) ? SSL_AES:0;
 376
 377         mask |= (ssl_digest_methods[SSL_MD_MD5_IDX ] == NULL) ? SSL_MD5 :0;
 378         mask |= (ssl_digest_methods[SSL_MD_SHA1_IDX] == NULL) ? SSL_SHA1:0;
 379
 380         return(mask);
 381         }
 382
 383 static void ssl_cipher_collect_ciphers(const SSL_METHOD *ssl_method,
 384                 int num_of_ciphers, unsigned long mask, CIPHER_ORDER *list,
 385                 CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
 386         {
 387         int i, list_num;
 388         SSL_CIPHER *c;
 389
 390         /*
 391          * We have num_of_ciphers descriptions compiled in, depending on the
 392          * method selected (SSLv2 and/or SSLv3, TLSv1 etc).
 393          * These will later be sorted in a linked list with at most num
 394          * entries.
 395          */
 396
 397         /* Get the initial list of ciphers */
 398         list_num = 0;   /* actual count of ciphers */
 399         for (i = 0; i < num_of_ciphers; i++)
 400                 {
 401                 c = ssl_method->get_cipher(i);
 402                 /* drop those that use any of that is not available */
 403                 if ((c != NULL) && c->valid && !(c->algorithms & mask))
 404                         {
 405                         list[list_num].cipher = c;
 406                         list[list_num].next = NULL;
 407                         list[list_num].prev = NULL;
 408                         list[list_num].active = 0;
 409                         list_num++;
 410 #ifdef KSSL_DEBUG
 411                         printf("\t%d: %s %lx %lx\n",i,c->name,c->id,c->algorithms);
 412 #endif  /* KSSL_DEBUG */
 413                         /*
 414                         if (!sk_push(ca_list,(char *)c)) goto err;
 415                         */
 416                         }
 417                 }
 418
 419         /*
 420          * Prepare linked list from list entries
 421          */
 422         for (i = 1; i < list_num - 1; i++)
 423                 {
 424                 list[i].prev = &(list[i-1]);
 425                 list[i].next = &(list[i+1]);
 426                 }
 427         if (list_num > 0)
 428                 {
 429                 (*head_p) = &(list[0]);
 430                 (*head_p)->prev = NULL;
 431                 (*head_p)->next = &(list[1]);
 432                 (*tail_p) = &(list[list_num - 1]);
 433                 (*tail_p)->prev = &(list[list_num - 2]);
 434                 (*tail_p)->next = NULL;
 435                 }
 436         }
 437
 438 static void ssl_cipher_collect_aliases(SSL_CIPHER **ca_list,
 439                         int num_of_group_aliases, unsigned long mask,
 440                         CIPHER_ORDER *head)
 441         {
 442         CIPHER_ORDER *ciph_curr;
 443         SSL_CIPHER **ca_curr;
 444         int i;
 445
 446         /*
 447          * First, add the real ciphers as already collected
 448          */
 449         ciph_curr = head;
 450         ca_curr = ca_list;
 451         while (ciph_curr != NULL)
 452                 {
 453                 *ca_curr = ciph_curr->cipher;
 454                 ca_curr++;
 455                 ciph_curr = ciph_curr->next;
 456                 }
 457
 458         /*
 459          * Now we add the available ones from the cipher_aliases[] table.
 460          * They represent either an algorithm, that must be fully
 461          * supported (not match any bit in mask) or represent a cipher
 462          * strength value (will be added in any case because algorithms=0).
 463          */
 464         for (i = 0; i < num_of_group_aliases; i++)
 465                 {
 466                 if ((i == 0) ||         /* always fetch "ALL" */
 467                     !(cipher_aliases[i].algorithms & mask))
 468                         {
 469                         *ca_curr = (SSL_CIPHER *)(cipher_aliases + i);
 470                         ca_curr++;
 471                         }
 472                 }
 473
 474         *ca_curr = NULL;        /* end of list */
 475         }
 476
 477 static void ssl_cipher_apply_rule(unsigned long algorithms, unsigned long mask,
 478                 unsigned long algo_strength, unsigned long mask_strength,
 479                 int rule, int strength_bits, CIPHER_ORDER *list,
 480                 CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
 481         {
 482         CIPHER_ORDER *head, *tail, *curr, *curr2, *tail2;
 483         SSL_CIPHER *cp;
 484         unsigned long ma, ma_s;
 485
 486 #ifdef CIPHER_DEBUG
 487         printf("Applying rule %d with %08lx %08lx %08lx %08lx (%d)\n",
 488                 rule, algorithms, mask, algo_strength, mask_strength,
 489                 strength_bits);
 490 #endif
 491
 492         curr = head = *head_p;
 493         curr2 = head;
 494         tail2 = tail = *tail_p;
 495         for (;;)
 496                 {
 497                 if ((curr == NULL) || (curr == tail2)) break;
 498                 curr = curr2;
 499                 curr2 = curr->next;
 500
 501                 cp = curr->cipher;
 502
 503                 /*
 504                  * Selection criteria is either the number of strength_bits
 505                  * or the algorithm used.
 506                  */
 507                 if (strength_bits == -1)
 508                         {
 509                         ma = mask & cp->algorithms;
 510                         ma_s = mask_strength & cp->algo_strength;
 511
 512 #ifdef CIPHER_DEBUG
 513                         printf("\nName: %s:\nAlgo = %08lx Algo_strength = %08lx\nMask = %08lx Mask_strength %08lx\n", cp->name, cp->algorithms, cp->algo_strength, mask, mask_strength);
 514                         printf("ma = %08lx ma_s %08lx, ma&algo=%08lx, ma_s&algos=%08lx\n", ma, ma_s, ma&algorithms, ma_s&algo_strength);
 515 #endif
 516                         /*
 517                          * Select: if none of the mask bit was met from the
 518                          * cipher or not all of the bits were met, the
 519                          * selection does not apply.
 520                          */
 521                         if (((ma == 0) && (ma_s == 0)) ||
 522                             ((ma & algorithms) != ma) ||
 523                             ((ma_s & algo_strength) != ma_s))
 524                                 continue; /* does not apply */
 525                         }
 526                 else if (strength_bits != cp->strength_bits)
 527                         continue;       /* does not apply */
 528
 529 #ifdef CIPHER_DEBUG
 530                 printf("Action = %d\n", rule);
 531 #endif
 532
 533                 /* add the cipher if it has not been added yet. */
 534                 if (rule == CIPHER_ADD)
 535                         {
 536                         if (!curr->active)
 537                                 {
 538                                 ll_append_tail(&head, curr, &tail);
 539                                 curr->active = 1;
 540                                 }
 541                         }
 542                 /* Move the added cipher to this location */
 543                 else if (rule == CIPHER_ORD)
 544                         {
 545                         if (curr->active)
 546                                 {
 547                                 ll_append_tail(&head, curr, &tail);
 548                                 }
 549                         }
 550                 else if (rule == CIPHER_DEL)
 551                         curr->active = 0;
 552                 else if (rule == CIPHER_KILL)
 553                         {
 554                         if (head == curr)
 555                                 head = curr->next;
 556                         else
 557                                 curr->prev->next = curr->next;
 558                         if (tail == curr)
 559                                 tail = curr->prev;
 560                         curr->active = 0;
 561                         if (curr->next != NULL)
 562                                 curr->next->prev = curr->prev;
 563                         if (curr->prev != NULL)
 564                                 curr->prev->next = curr->next;
 565                         curr->next = NULL;
 566                         curr->prev = NULL;
 567                         }
 568                 }
 569
 570         *head_p = head;
 571         *tail_p = tail;
 572         }
 573
 574 static int ssl_cipher_strength_sort(CIPHER_ORDER *list, CIPHER_ORDER **head_p,
 575                                      CIPHER_ORDER **tail_p)
 576         {
 577         int max_strength_bits, i, *number_uses;
 578         CIPHER_ORDER *curr;
 579
 580         /*
 581          * This routine sorts the ciphers with descending strength. The sorting
 582          * must keep the pre-sorted sequence, so we apply the normal sorting
 583          * routine as '+' movement to the end of the list.
 584          */
 585         max_strength_bits = 0;
 586         curr = *head_p;
 587         while (curr != NULL)
 588                 {
 589                 if (curr->active &&
 590                     (curr->cipher->strength_bits > max_strength_bits))
 591                     max_strength_bits = curr->cipher->strength_bits;
 592                 curr = curr->next;
 593                 }
 594
 595         number_uses = OPENSSL_malloc((max_strength_bits + 1) * sizeof(int));
 596         if (!number_uses)
 597         {
 598                 SSLerr(SSL_F_SSL_CIPHER_STRENGTH_SORT,ERR_R_MALLOC_FAILURE);
 599                 return(0);
 600         }
 601         memset(number_uses, 0, (max_strength_bits + 1) * sizeof(int));
 602
 603         /*
 604          * Now find the strength_bits values actually used
 605          */
 606         curr = *head_p;
 607         while (curr != NULL)
 608                 {
 609                 if (curr->active)
 610                         number_uses[curr->cipher->strength_bits]++;
 611                 curr = curr->next;
 612                 }
 613         /*
 614          * Go through the list of used strength_bits values in descending
 615          * order.
 616          */
 617         for (i = max_strength_bits; i >= 0; i--)
 618                 if (number_uses[i] > 0)
 619                         ssl_cipher_apply_rule(0, 0, 0, 0, CIPHER_ORD, i,
 620                                         list, head_p, tail_p);
 621
 622         OPENSSL_free(number_uses);
 623         return(1);
 624         }
 625
 626 static int ssl_cipher_process_rulestr(const char *rule_str,
 627                 CIPHER_ORDER *list, CIPHER_ORDER **head_p,
 628                 CIPHER_ORDER **tail_p, SSL_CIPHER **ca_list)
 629         {
 630         unsigned long algorithms, mask, algo_strength, mask_strength;
 631         const char *l, *start, *buf;
 632         int j, multi, found, rule, retval, ok, buflen;
 633         char ch;
 634
 635         retval = 1;
 636         l = rule_str;
 637         for (;;)
 638                 {
 639                 ch = *l;
 640
 641                 if (ch == '\0')
 642                         break;          /* done */
 643                 if (ch == '-')
 644                         { rule = CIPHER_DEL; l++; }
 645                 else if (ch == '+')
 646                         { rule = CIPHER_ORD; l++; }
 647                 else if (ch == '!')
 648                         { rule = CIPHER_KILL; l++; }
 649                 else if (ch == '@')
 650                         { rule = CIPHER_SPECIAL; l++; }
 651                 else
 652                         { rule = CIPHER_ADD; }
 653
 654                 if (ITEM_SEP(ch))
 655                         {
 656                         l++;
 657                         continue;
 658                         }
 659
 660                 algorithms = mask = algo_strength = mask_strength = 0;
 661
 662                 start=l;
 663                 for (;;)
 664                         {
 665                         ch = *l;
 666                         buf = l;
 667                         buflen = 0;
 668 #ifndef CHARSET_EBCDIC
 669                         while ( ((ch >= 'A') && (ch <= 'Z')) ||
 670                                 ((ch >= '0') && (ch <= '9')) ||
 671                                 ((ch >= 'a') && (ch <= 'z')) ||
 672                                  (ch == '-'))
 673 #else
 674                         while ( isalnum(ch) || (ch == '-'))
 675 #endif
 676                                  {
 677                                  ch = *(++l);
 678                                  buflen++;
 679                                  }
 680
 681                         if (buflen == 0)
 682                                 {
 683                                 /*
 684                                  * We hit something we cannot deal with,
 685                                  * it is no command or separator nor
 686                                  * alphanumeric, so we call this an error.
 687                                  */
 688                                 SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR,
 689                                        SSL_R_INVALID_COMMAND);
 690                                 retval = found = 0;
 691                                 l++;
 692                                 break;
 693                                 }
 694
 695                         if (rule == CIPHER_SPECIAL)
 696                                 {
 697                                 found = 0; /* unused -- avoid compiler warning */
 698                                 break;  /* special treatment */
 699                                 }
 700
 701                         /* check for multi-part specification */
 702                         if (ch == '+')
 703                                 {
 704                                 multi=1;
 705                                 l++;
 706                                 }
 707                         else
 708                                 multi=0;
 709
 710                         /*
 711                          * Now search for the cipher alias in the ca_list. Be careful
 712                          * with the strncmp, because the "buflen" limitation
 713                          * will make the rule "ADH:SOME" and the cipher
 714                          * "ADH-MY-CIPHER" look like a match for buflen=3.
 715                          * So additionally check whether the cipher name found
 716                          * has the correct length. We can save a strlen() call:
 717                          * just checking for the '\0' at the right place is
 718                          * sufficient, we have to strncmp() anyway. (We cannot
 719                          * use strcmp(), because buf is not '\0' terminated.)
 720                          */
 721                          j = found = 0;
 722                          while (ca_list[j])
 723                                 {
 724                                 if (!strncmp(buf, ca_list[j]->name, buflen) &&
 725                                     (ca_list[j]->name[buflen] == '\0'))
 726                                         {
 727                                         found = 1;
 728                                         break;
 729                                         }
 730                                 else
 731                                         j++;
 732                                 }
 733                         if (!found)
 734                                 break;  /* ignore this entry */
 735
 736                         algorithms |= ca_list[j]->algorithms;
 737                         mask |= ca_list[j]->mask;
 738                         algo_strength |= ca_list[j]->algo_strength;
 739                         mask_strength |= ca_list[j]->mask_strength;
 740
 741                         if (!multi) break;
 742                         }
 743
 744                 /*
 745                  * Ok, we have the rule, now apply it
 746                  */
 747                 if (rule == CIPHER_SPECIAL)
 748                         {       /* special command */
 749                         ok = 0;
 750                         if ((buflen == 8) &&
 751                                 !strncmp(buf, "STRENGTH", 8))
 752                                 ok = ssl_cipher_strength_sort(list,
 753                                         head_p, tail_p);
 754                         else
 755                                 SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR,
 756                                         SSL_R_INVALID_COMMAND);
 757                         if (ok == 0)
 758                                 retval = 0;
 759                         /*
 760                          * We do not support any "multi" options
 761                          * together with "@", so throw away the
 762                          * rest of the command, if any left, until
 763                          * end or ':' is found.
 764                          */
 765                         while ((*l != '\0') && ITEM_SEP(*l))
 766                                 l++;
 767                         }
 768                 else if (found)
 769                         {
 770                         ssl_cipher_apply_rule(algorithms, mask,
 771                                 algo_strength, mask_strength, rule, -1,
 772                                 list, head_p, tail_p);
 773                         }
 774                 else
 775                         {
 776                         while ((*l != '\0') && ITEM_SEP(*l))
 777                                 l++;
 778                         }
 779                 if (*l == '\0') break; /* done */
 780                 }
 781
 782         return(retval);
 783         }
 784
 785 STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method,
 786                 STACK_OF(SSL_CIPHER) **cipher_list,
 787                 STACK_OF(SSL_CIPHER) **cipher_list_by_id,
 788                 const char *rule_str)
 789         {
 790         int ok, num_of_ciphers, num_of_alias_max, num_of_group_aliases;
 791         unsigned long disabled_mask;
 792         STACK_OF(SSL_CIPHER) *cipherstack;
 793         const char *rule_p;
 794         CIPHER_ORDER *list = NULL, *head = NULL, *tail = NULL, *curr;
 795         SSL_CIPHER **ca_list = NULL;
 796
 797         /*
 798          * Return with error if nothing to do.
 799          */
 800         if (rule_str == NULL) return(NULL);
 801
 802         if (init_ciphers)
 803                 {
 804                 CRYPTO_w_lock(CRYPTO_LOCK_SSL);
 805                 if (init_ciphers) load_ciphers();
 806                 CRYPTO_w_unlock(CRYPTO_LOCK_SSL);
 807                 }
 808
 809         /*
 810          * To reduce the work to do we only want to process the compiled
 811          * in algorithms, so we first get the mask of disabled ciphers.
 812          */
 813         disabled_mask = ssl_cipher_get_disabled();
 814
 815         /*
 816          * Now we have to collect the available ciphers from the compiled
 817          * in ciphers. We cannot get more than the number compiled in, so
 818          * it is used for allocation.
 819          */
 820         num_of_ciphers = ssl_method->num_ciphers();
 821 #ifdef KSSL_DEBUG
 822         printf("ssl_create_cipher_list() for %d ciphers\n", num_of_ciphers);
 823 #endif    /* KSSL_DEBUG */
 824         list = (CIPHER_ORDER *)OPENSSL_malloc(sizeof(CIPHER_ORDER) * num_of_ciphers);
 825         if (list == NULL)
 826                 {
 827                 SSLerr(SSL_F_SSL_CREATE_CIPHER_LIST,ERR_R_MALLOC_FAILURE);
 828                 return(NULL);   /* Failure */
 829                 }
 830
 831         ssl_cipher_collect_ciphers(ssl_method, num_of_ciphers, disabled_mask,
 832                                    list, &head, &tail);
 833
 834         /*
 835          * We also need cipher aliases for selecting based on the rule_str.
 836          * There might be two types of entries in the rule_str: 1) names
 837          * of ciphers themselves 2) aliases for groups of ciphers.
 838          * For 1) we need the available ciphers and for 2) the cipher
 839          * groups of cipher_aliases added together in one list (otherwise
 840          * we would be happy with just the cipher_aliases table).
 841          */
 842         num_of_group_aliases = sizeof(cipher_aliases) / sizeof(SSL_CIPHER);
 843         num_of_alias_max = num_of_ciphers + num_of_group_aliases + 1;
 844         ca_list =
 845                 (SSL_CIPHER **)OPENSSL_malloc(sizeof(SSL_CIPHER *) * num_of_alias_max);
 846         if (ca_list == NULL)
 847                 {
 848                 OPENSSL_free(list);
 849                 SSLerr(SSL_F_SSL_CREATE_CIPHER_LIST,ERR_R_MALLOC_FAILURE);
 850                 return(NULL);   /* Failure */
 851                 }
 852         ssl_cipher_collect_aliases(ca_list, num_of_group_aliases, disabled_mask,
 853                                    head);
 854
 855         /*
 856          * If the rule_string begins with DEFAULT, apply the default rule
 857          * before using the (possibly available) additional rules.
 858          */
 859         ok = 1;
 860         rule_p = rule_str;
 861         if (strncmp(rule_str,"DEFAULT",7) == 0)
 862                 {
 863                 ok = ssl_cipher_process_rulestr(SSL_DEFAULT_CIPHER_LIST,
 864                         list, &head, &tail, ca_list);
 865                 rule_p += 7;
 866                 if (*rule_p == ':')
 867                         rule_p++;
 868                 }
 869
 870         if (ok && (strlen(rule_p) > 0))
 871                 ok = ssl_cipher_process_rulestr(rule_p, list, &head, &tail,
 872                                                 ca_list);
 873
 874         OPENSSL_free(ca_list);  /* Not needed anymore */
 875
 876         if (!ok)
 877                 {       /* Rule processing failure */
 878                 OPENSSL_free(list);
 879                 return(NULL);
 880                 }
 881         /*
 882          * Allocate new "cipherstack" for the result, return with error
 883          * if we cannot get one.
 884          */
 885         if ((cipherstack = sk_SSL_CIPHER_new_null()) == NULL)
 886                 {
 887                 OPENSSL_free(list);
 888                 return(NULL);
 889                 }
 890
 891         /*
 892          * The cipher selection for the list is done. The ciphers are added
 893          * to the resulting precedence to the STACK_OF(SSL_CIPHER).
 894          */
 895         for (curr = head; curr != NULL; curr = curr->next)
 896                 {
 897                 if (curr->active)
 898                         {
 899                         sk_SSL_CIPHER_push(cipherstack, curr->cipher);
 900 #ifdef CIPHER_DEBUG
 901                         printf("<%s>\n",curr->cipher->name);
 902 #endif
 903                         }
 904                 }
 905         OPENSSL_free(list);     /* Not needed any longer */
 906
 907         /*
 908          * The following passage is a little bit odd. If pointer variables
 909          * were supplied to hold STACK_OF(SSL_CIPHER) return information,
 910          * the old memory pointed to is free()ed. Then, however, the
 911          * cipher_list entry will be assigned just a copy of the returned
 912          * cipher stack. For cipher_list_by_id a copy of the cipher stack
 913          * will be created. See next comment...
 914          */
 915         if (cipher_list != NULL)
 916                 {
 917                 if (*cipher_list != NULL)
 918                         sk_SSL_CIPHER_free(*cipher_list);
 919                 *cipher_list = cipherstack;
 920                 }
 921
 922         if (cipher_list_by_id != NULL)
 923                 {
 924                 if (*cipher_list_by_id != NULL)
 925                         sk_SSL_CIPHER_free(*cipher_list_by_id);
 926                 *cipher_list_by_id = sk_SSL_CIPHER_dup(cipherstack);
 927                 }
 928
 929         /*
 930          * Now it is getting really strange. If something failed during
 931          * the previous pointer assignment or if one of the pointers was
 932          * not requested, the error condition is met. That might be
 933          * discussable. The strange thing is however that in this case
 934          * the memory "ret" pointed to is "free()ed" and hence the pointer
 935          * cipher_list becomes wild. The memory reserved for
 936          * cipher_list_by_id however is not "free()ed" and stays intact.
 937          */
 938         if (    (cipher_list_by_id == NULL) ||
 939                 (*cipher_list_by_id == NULL) ||
 940                 (cipher_list == NULL) ||
 941                 (*cipher_list == NULL))
 942                 {
 943                 sk_SSL_CIPHER_free(cipherstack);
 944                 return(NULL);
 945                 }
 946
 947         sk_SSL_CIPHER_set_cmp_func(*cipher_list_by_id,ssl_cipher_ptr_id_cmp);
 948
 949         return(cipherstack);
 950         }
 951
 952 char *SSL_CIPHER_description(SSL_CIPHER *cipher, char *buf, int len)
 953         {
 954         int is_export,pkl,kl;
 955         char *ver,*exp;
 956         char *kx,*au,*enc,*mac;
 957         unsigned long alg,alg2,alg_s;
 958 #ifdef KSSL_DEBUG
 959         static char *format="%-23s %s Kx=%-8s Au=%-4s Enc=%-9s Mac=%-4s%s AL=%lx\n";
 960 #else
 961         static char *format="%-23s %s Kx=%-8s Au=%-4s Enc=%-9s Mac=%-4s%s\n";
 962 #endif /* KSSL_DEBUG */
 963
 964         alg=cipher->algorithms;
 965         alg_s=cipher->algo_strength;
 966         alg2=cipher->algorithm2;
 967
 968         is_export=SSL_C_IS_EXPORT(cipher);
 969         pkl=SSL_C_EXPORT_PKEYLENGTH(cipher);
 970         kl=SSL_C_EXPORT_KEYLENGTH(cipher);
 971         exp=is_export?" export":"";
 972
 973         if (alg & SSL_SSLV2)
 974                 ver="SSLv2";
 975         else if (alg & SSL_SSLV3)
 976                 ver="SSLv3";
 977         else
 978                 ver="unknown";
 979
 980         switch (alg&SSL_MKEY_MASK)
 981                 {
 982         case SSL_kRSA:
 983                 kx=is_export?(pkl == 512 ? "RSA(512)" : "RSA(1024)"):"RSA";
 984                 break;
 985         case SSL_kDHr:
 986                 kx="DH/RSA";
 987                 break;
 988         case SSL_kDHd:
 989                 kx="DH/DSS";
 990                 break;
 991         case SSL_kKRB5:         /* VRS */
 992         case SSL_KRB5:          /* VRS */
 993             kx="KRB5";
 994             break;
 995         case SSL_kFZA:
 996                 kx="Fortezza";
 997                 break;
 998         case SSL_kEDH:
 999                 kx=is_export?(pkl == 512 ? "DH(512)" : "DH(1024)"):"DH";
1000                 break;
1001         case SSL_kECDH:
1002         case SSL_kECDHE:
1003                 kx=is_export?"ECDH(<=163)":"ECDH";
1004                 break;
1005         default:
1006                 kx="unknown";
1007                 }
1008
1009         switch (alg&SSL_AUTH_MASK)
1010                 {
1011         case SSL_aRSA:
1012                 au="RSA";
1013                 break;
1014         case SSL_aDSS:
1015                 au="DSS";
1016                 break;
1017         case SSL_aDH:
1018                 au="DH";
1019                 break;
1020         case SSL_aKRB5:         /* VRS */
1021         case SSL_KRB5:          /* VRS */
1022             au="KRB5";
1023             break;
1024         case SSL_aFZA:
1025         case SSL_aNULL:
1026                 au="None";
1027                 break;
1028         case SSL_aECDSA:
1029                 au="ECDSA";
1030                 break;
1031         default:
1032                 au="unknown";
1033                 break;
1034                 }
1035
1036         switch (alg&SSL_ENC_MASK)
1037                 {
1038         case SSL_DES:
1039                 enc=(is_export && kl == 5)?"DES(40)":"DES(56)";
1040                 break;
1041         case SSL_3DES:
1042                 enc="3DES(168)";
1043                 break;
1044         case SSL_RC4:
1045                 enc=is_export?(kl == 5 ? "RC4(40)" : "RC4(56)")
1046                   :((alg2&SSL2_CF_8_BYTE_ENC)?"RC4(64)":"RC4(128)");
1047                 break;
1048         case SSL_RC2:
1049                 enc=is_export?(kl == 5 ? "RC2(40)" : "RC2(56)"):"RC2(128)";
1050                 break;
1051         case SSL_IDEA:
1052                 enc="IDEA(128)";
1053                 break;
1054         case SSL_eFZA:
1055                 enc="Fortezza";
1056                 break;
1057         case SSL_eNULL:
1058                 enc="None";
1059                 break;
1060         case SSL_AES:
1061                 switch(cipher->strength_bits)
1062                         {
1063                 case 128: enc="AES(128)"; break;
1064                 case 192: enc="AES(192)"; break;
1065                 case 256: enc="AES(256)"; break;
1066                 default: enc="AES(?""?""?)"; break;
1067                         }
1068                 break;
1069         default:
1070                 enc="unknown";
1071                 break;
1072                 }
1073
1074         switch (alg&SSL_MAC_MASK)
1075                 {
1076         case SSL_MD5:
1077                 mac="MD5";
1078                 break;
1079         case SSL_SHA1:
1080                 mac="SHA1";
1081                 break;
1082         default:
1083                 mac="unknown";
1084                 break;
1085                 }
1086
1087         if (buf == NULL)
1088                 {
1089                 len=128;
1090                 buf=OPENSSL_malloc(len);
1091                 if (buf == NULL) return("OPENSSL_malloc Error");
1092                 }
1093         else if (len < 128)
1094                 return("Buffer too small");
1095
1096 #ifdef KSSL_DEBUG
1097         BIO_snprintf(buf,len,format,cipher->name,ver,kx,au,enc,mac,exp,alg);
1098 #else
1099         BIO_snprintf(buf,len,format,cipher->name,ver,kx,au,enc,mac,exp);
1100 #endif /* KSSL_DEBUG */
1101         return(buf);
1102         }
1103
1104 char *SSL_CIPHER_get_version(SSL_CIPHER *c)
1105         {
1106         int i;
1107
1108         if (c == NULL) return("(NONE)");
1109         i=(int)(c->id>>24L);
1110         if (i == 3)
1111                 return("TLSv1/SSLv3");
1112         else if (i == 2)
1113                 return("SSLv2");
1114         else
1115                 return("unknown");
1116         }
1117
1118 /* return the actual cipher being used */
1119 const char *SSL_CIPHER_get_name(SSL_CIPHER *c)
1120         {
1121         if (c != NULL)
1122                 return(c->name);
1123         return("(NONE)");
1124         }
1125
1126 /* number of bits for symmetric cipher */
1127 int SSL_CIPHER_get_bits(SSL_CIPHER *c, int *alg_bits)
1128         {
1129         int ret=0;
1130
1131         if (c != NULL)
1132                 {
1133                 if (alg_bits != NULL) *alg_bits = c->alg_bits;
1134                 ret = c->strength_bits;
1135                 }
1136         return(ret);
1137         }
1138
1139 SSL_COMP *ssl3_comp_find(STACK_OF(SSL_COMP) *sk, int n)
1140         {
1141         SSL_COMP *ctmp;
1142         int i,nn;
1143
1144         if ((n == 0) || (sk == NULL)) return(NULL);
1145         nn=sk_SSL_COMP_num(sk);
1146         for (i=0; i<nn; i++)
1147                 {
1148                 ctmp=sk_SSL_COMP_value(sk,i);
1149                 if (ctmp->id == n)
1150                         return(ctmp);
1151                 }
1152         return(NULL);
1153         }
1154
1155 STACK_OF(SSL_COMP) *SSL_COMP_get_compression_methods(void)
1156         {
1157         load_builtin_compressions();
1158         return(ssl_comp_methods);
1159         }
1160
1161 int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm)
1162         {
1163         SSL_COMP *comp;
1164
1165         if (cm == NULL || cm->type == NID_undef)
1166                 return 1;
1167
1168         /* According to draft-ietf-tls-compression-04.txt, the
1169            compression number ranges should be the following:
1170
1171            0 to 63:    methods defined by the IETF
1172            64 to 192:  external party methods assigned by IANA
1173            193 to 255: reserved for private use */
1174         if (id < 193 || id > 255)
1175                 {
1176                 SSLerr(SSL_F_SSL_COMP_ADD_COMPRESSION_METHOD,SSL_R_COMPRESSION_ID_NOT_WITHIN_PRIVATE_RANGE);
1177                 return 0;
1178                 }
1179
1180         MemCheck_off();
1181         comp=(SSL_COMP *)OPENSSL_malloc(sizeof(SSL_COMP));
1182         comp->id=id;
1183         comp->method=cm;
1184         load_builtin_compressions();
1185         if ((ssl_comp_methods == NULL)
1186                 || !sk_SSL_COMP_push(ssl_comp_methods,comp))
1187                 {
1188                 OPENSSL_free(comp);
1189                 MemCheck_on();
1190                 SSLerr(SSL_F_SSL_COMP_ADD_COMPRESSION_METHOD,ERR_R_MALLOC_FAILURE);
1191                 return(0);
1192                 }
1193         else
1194                 {
1195                 MemCheck_on();
1196                 return(1);
1197                 }
1198         }