crypto/heimdal/lib/gssapi/krb5/arcfour.c

   1 /*
   2  * Copyright (c) 2003 - 2006 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "gsskrb5_locl.h"
  35
  36 /*
  37  * Implements draft-brezak-win2k-krb-rc4-hmac-04.txt
  38  *
  39  * The arcfour message have the following formats:
  40  *
  41  * MIC token
  42  *      TOK_ID[2] = 01 01
  43  *      SGN_ALG[2] = 11 00
  44  *      Filler[4]
  45  *      SND_SEQ[8]
  46  *      SGN_CKSUM[8]
  47  *
  48  * WRAP token
  49  *      TOK_ID[2] = 02 01
  50  *      SGN_ALG[2];
  51  *      SEAL_ALG[2]
  52  *      Filler[2]
  53  *      SND_SEQ[2]
  54  *      SGN_CKSUM[8]
  55  *      Confounder[8]
  56  */
  57
  58 /*
  59  * WRAP in DCE-style have a fixed size header, the oid and length over
  60  * the WRAP header is a total of
  61  * GSS_ARCFOUR_WRAP_TOKEN_DCE_DER_HEADER_SIZE +
  62  * GSS_ARCFOUR_WRAP_TOKEN_SIZE byte (ie total of 45 bytes overhead,
  63  * remember the 2 bytes from APPL [0] SEQ).
  64  */
  65
  66 #define GSS_ARCFOUR_WRAP_TOKEN_SIZE 32
  67 #define GSS_ARCFOUR_WRAP_TOKEN_DCE_DER_HEADER_SIZE 13
  68
  69
  70 static krb5_error_code
  71 arcfour_mic_key(krb5_context context, krb5_keyblock *key,
  72                 void *cksum_data, size_t cksum_size,
  73                 void *key6_data, size_t key6_size)
  74 {
  75     krb5_error_code ret;
  76
  77     Checksum cksum_k5;
  78     krb5_keyblock key5;
  79     char k5_data[16];
  80
  81     Checksum cksum_k6;
  82
  83     char T[4];
  84
  85     memset(T, 0, 4);
  86     cksum_k5.checksum.data = k5_data;
  87     cksum_k5.checksum.length = sizeof(k5_data);
  88
  89     if (key->keytype == ENCTYPE_ARCFOUR_HMAC_MD5_56) {
  90         char L40[14] = "fortybits";
  91
  92         memcpy(L40 + 10, T, sizeof(T));
  93         ret = krb5_hmac(context, CKSUMTYPE_RSA_MD5,
  94                         L40, 14, 0, key, &cksum_k5);
  95         memset(&k5_data[7], 0xAB, 9);
  96     } else {
  97         ret = krb5_hmac(context, CKSUMTYPE_RSA_MD5,
  98                         T, 4, 0, key, &cksum_k5);
  99     }
 100     if (ret)
 101         return ret;
 102
 103     key5.keytype = ENCTYPE_ARCFOUR_HMAC_MD5;
 104     key5.keyvalue = cksum_k5.checksum;
 105
 106     cksum_k6.checksum.data = key6_data;
 107     cksum_k6.checksum.length = key6_size;
 108
 109     return krb5_hmac(context, CKSUMTYPE_RSA_MD5,
 110                      cksum_data, cksum_size, 0, &key5, &cksum_k6);
 111 }
 112
 113
 114 static krb5_error_code
 115 arcfour_mic_cksum(krb5_context context,
 116                   krb5_keyblock *key, unsigned usage,
 117                   u_char *sgn_cksum, size_t sgn_cksum_sz,
 118                   const u_char *v1, size_t l1,
 119                   const void *v2, size_t l2,
 120                   const void *v3, size_t l3)
 121 {
 122     Checksum CKSUM;
 123     u_char *ptr;
 124     size_t len;
 125     krb5_crypto crypto;
 126     krb5_error_code ret;
 127
 128     assert(sgn_cksum_sz == 8);
 129
 130     len = l1 + l2 + l3;
 131
 132     ptr = malloc(len);
 133     if (ptr == NULL)
 134         return ENOMEM;
 135
 136     memcpy(ptr, v1, l1);
 137     memcpy(ptr + l1, v2, l2);
 138     memcpy(ptr + l1 + l2, v3, l3);
 139
 140     ret = krb5_crypto_init(context, key, 0, &crypto);
 141     if (ret) {
 142         free(ptr);
 143         return ret;
 144     }
 145
 146     ret = krb5_create_checksum(context,
 147                                crypto,
 148                                usage,
 149                                0,
 150                                ptr, len,
 151                                &CKSUM);
 152     free(ptr);
 153     if (ret == 0) {
 154         memcpy(sgn_cksum, CKSUM.checksum.data, sgn_cksum_sz);
 155         free_Checksum(&CKSUM);
 156     }
 157     krb5_crypto_destroy(context, crypto);
 158
 159     return ret;
 160 }
 161
 162
 163 OM_uint32
 164 _gssapi_get_mic_arcfour(OM_uint32 * minor_status,
 165                         const gsskrb5_ctx context_handle,
 166                         krb5_context context,
 167                         gss_qop_t qop_req,
 168                         const gss_buffer_t message_buffer,
 169                         gss_buffer_t message_token,
 170                         krb5_keyblock *key)
 171 {
 172     krb5_error_code ret;
 173     int32_t seq_number;
 174     size_t len, total_len;
 175     u_char k6_data[16], *p0, *p;
 176     EVP_CIPHER_CTX rc4_key;
 177
 178     _gsskrb5_encap_length (22, &len, &total_len, GSS_KRB5_MECHANISM);
 179
 180     message_token->length = total_len;
 181     message_token->value  = malloc (total_len);
 182     if (message_token->value == NULL) {
 183         *minor_status = ENOMEM;
 184         return GSS_S_FAILURE;
 185     }
 186
 187     p0 = _gssapi_make_mech_header(message_token->value,
 188                                   len,
 189                                   GSS_KRB5_MECHANISM);
 190     p = p0;
 191
 192     *p++ = 0x01; /* TOK_ID */
 193     *p++ = 0x01;
 194     *p++ = 0x11; /* SGN_ALG */
 195     *p++ = 0x00;
 196     *p++ = 0xff; /* Filler */
 197     *p++ = 0xff;
 198     *p++ = 0xff;
 199     *p++ = 0xff;
 200
 201     p = NULL;
 202
 203     ret = arcfour_mic_cksum(context,
 204                             key, KRB5_KU_USAGE_SIGN,
 205                             p0 + 16, 8,  /* SGN_CKSUM */
 206                             p0, 8, /* TOK_ID, SGN_ALG, Filer */
 207                             message_buffer->value, message_buffer->length,
 208                             NULL, 0);
 209     if (ret) {
 210         _gsskrb5_release_buffer(minor_status, message_token);
 211         *minor_status = ret;
 212         return GSS_S_FAILURE;
 213     }
 214
 215     ret = arcfour_mic_key(context, key,
 216                           p0 + 16, 8, /* SGN_CKSUM */
 217                           k6_data, sizeof(k6_data));
 218     if (ret) {
 219         _gsskrb5_release_buffer(minor_status, message_token);
 220         *minor_status = ret;
 221         return GSS_S_FAILURE;
 222     }
 223
 224     HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
 225     krb5_auth_con_getlocalseqnumber (context,
 226                                      context_handle->auth_context,
 227                                      &seq_number);
 228     p = p0 + 8; /* SND_SEQ */
 229     _gsskrb5_encode_be_om_uint32(seq_number, p);
 230
 231     krb5_auth_con_setlocalseqnumber (context,
 232                                      context_handle->auth_context,
 233                                      ++seq_number);
 234     HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
 235
 236     memset (p + 4, (context_handle->more_flags & LOCAL) ? 0 : 0xff, 4);
 237
 238     EVP_CIPHER_CTX_init(&rc4_key);
 239     EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
 240     EVP_Cipher(&rc4_key, p, p, 8);
 241     EVP_CIPHER_CTX_cleanup(&rc4_key);
 242
 243     memset(k6_data, 0, sizeof(k6_data));
 244
 245     *minor_status = 0;
 246     return GSS_S_COMPLETE;
 247 }
 248
 249
 250 OM_uint32
 251 _gssapi_verify_mic_arcfour(OM_uint32 * minor_status,
 252                            const gsskrb5_ctx context_handle,
 253                            krb5_context context,
 254                            const gss_buffer_t message_buffer,
 255                            const gss_buffer_t token_buffer,
 256                            gss_qop_t * qop_state,
 257                            krb5_keyblock *key,
 258                            const char *type)
 259 {
 260     krb5_error_code ret;
 261     uint32_t seq_number;
 262     OM_uint32 omret;
 263     u_char SND_SEQ[8], cksum_data[8], *p;
 264     char k6_data[16];
 265     int cmp;
 266
 267     if (qop_state)
 268         *qop_state = 0;
 269
 270     p = token_buffer->value;
 271     omret = _gsskrb5_verify_header (&p,
 272                                        token_buffer->length,
 273                                        type,
 274                                        GSS_KRB5_MECHANISM);
 275     if (omret)
 276         return omret;
 277
 278     if (memcmp(p, "\x11\x00", 2) != 0) /* SGN_ALG = HMAC MD5 ARCFOUR */
 279         return GSS_S_BAD_SIG;
 280     p += 2;
 281     if (memcmp (p, "\xff\xff\xff\xff", 4) != 0)
 282         return GSS_S_BAD_MIC;
 283     p += 4;
 284
 285     ret = arcfour_mic_cksum(context,
 286                             key, KRB5_KU_USAGE_SIGN,
 287                             cksum_data, sizeof(cksum_data),
 288                             p - 8, 8,
 289                             message_buffer->value, message_buffer->length,
 290                             NULL, 0);
 291     if (ret) {
 292         *minor_status = ret;
 293         return GSS_S_FAILURE;
 294     }
 295
 296     ret = arcfour_mic_key(context, key,
 297                           cksum_data, sizeof(cksum_data),
 298                           k6_data, sizeof(k6_data));
 299     if (ret) {
 300         *minor_status = ret;
 301         return GSS_S_FAILURE;
 302     }
 303
 304     cmp = ct_memcmp(cksum_data, p + 8, 8);
 305     if (cmp) {
 306         *minor_status = 0;
 307         return GSS_S_BAD_MIC;
 308     }
 309
 310     {
 311         EVP_CIPHER_CTX rc4_key;
 312
 313         EVP_CIPHER_CTX_init(&rc4_key);
 314         EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, (void *)k6_data, NULL, 0);
 315         EVP_Cipher(&rc4_key, SND_SEQ, p, 8);
 316         EVP_CIPHER_CTX_cleanup(&rc4_key);
 317
 318         memset(k6_data, 0, sizeof(k6_data));
 319     }
 320
 321     _gsskrb5_decode_be_om_uint32(SND_SEQ, &seq_number);
 322
 323     if (context_handle->more_flags & LOCAL)
 324         cmp = memcmp(&SND_SEQ[4], "\xff\xff\xff\xff", 4);
 325     else
 326         cmp = memcmp(&SND_SEQ[4], "\x00\x00\x00\x00", 4);
 327
 328     memset(SND_SEQ, 0, sizeof(SND_SEQ));
 329     if (cmp != 0) {
 330         *minor_status = 0;
 331         return GSS_S_BAD_MIC;
 332     }
 333
 334     HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
 335     omret = _gssapi_msg_order_check(context_handle->order, seq_number);
 336     HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
 337     if (omret)
 338         return omret;
 339
 340     *minor_status = 0;
 341     return GSS_S_COMPLETE;
 342 }
 343
 344 OM_uint32
 345 _gssapi_wrap_arcfour(OM_uint32 * minor_status,
 346                      const gsskrb5_ctx context_handle,
 347                      krb5_context context,
 348                      int conf_req_flag,
 349                      gss_qop_t qop_req,
 350                      const gss_buffer_t input_message_buffer,
 351                      int * conf_state,
 352                      gss_buffer_t output_message_buffer,
 353                      krb5_keyblock *key)
 354 {
 355     u_char Klocaldata[16], k6_data[16], *p, *p0;
 356     size_t len, total_len, datalen;
 357     krb5_keyblock Klocal;
 358     krb5_error_code ret;
 359     int32_t seq_number;
 360
 361     if (conf_state)
 362         *conf_state = 0;
 363
 364     datalen = input_message_buffer->length;
 365
 366     if (IS_DCE_STYLE(context_handle)) {
 367         len = GSS_ARCFOUR_WRAP_TOKEN_SIZE;
 368         _gssapi_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
 369         total_len += datalen;
 370     } else {
 371         datalen += 1; /* padding */
 372         len = datalen + GSS_ARCFOUR_WRAP_TOKEN_SIZE;
 373         _gssapi_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
 374     }
 375
 376     output_message_buffer->length = total_len;
 377     output_message_buffer->value  = malloc (total_len);
 378     if (output_message_buffer->value == NULL) {
 379         *minor_status = ENOMEM;
 380         return GSS_S_FAILURE;
 381     }
 382
 383     p0 = _gssapi_make_mech_header(output_message_buffer->value,
 384                                   len,
 385                                   GSS_KRB5_MECHANISM);
 386     p = p0;
 387
 388     *p++ = 0x02; /* TOK_ID */
 389     *p++ = 0x01;
 390     *p++ = 0x11; /* SGN_ALG */
 391     *p++ = 0x00;
 392     if (conf_req_flag) {
 393         *p++ = 0x10; /* SEAL_ALG */
 394         *p++ = 0x00;
 395     } else {
 396         *p++ = 0xff; /* SEAL_ALG */
 397         *p++ = 0xff;
 398     }
 399     *p++ = 0xff; /* Filler */
 400     *p++ = 0xff;
 401
 402     p = NULL;
 403
 404     HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
 405     krb5_auth_con_getlocalseqnumber (context,
 406                                      context_handle->auth_context,
 407                                      &seq_number);
 408
 409     _gsskrb5_encode_be_om_uint32(seq_number, p0 + 8);
 410
 411     krb5_auth_con_setlocalseqnumber (context,
 412                                      context_handle->auth_context,
 413                                      ++seq_number);
 414     HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
 415
 416     memset (p0 + 8 + 4,
 417             (context_handle->more_flags & LOCAL) ? 0 : 0xff,
 418             4);
 419
 420     krb5_generate_random_block(p0 + 24, 8); /* fill in Confounder */
 421
 422     /* p points to data */
 423     p = p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE;
 424     memcpy(p, input_message_buffer->value, input_message_buffer->length);
 425
 426     if (!IS_DCE_STYLE(context_handle))
 427         p[input_message_buffer->length] = 1; /* padding */
 428
 429     ret = arcfour_mic_cksum(context,
 430                             key, KRB5_KU_USAGE_SEAL,
 431                             p0 + 16, 8, /* SGN_CKSUM */
 432                             p0, 8, /* TOK_ID, SGN_ALG, SEAL_ALG, Filler */
 433                             p0 + 24, 8, /* Confounder */
 434                             p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE,
 435                             datalen);
 436     if (ret) {
 437         *minor_status = ret;
 438         _gsskrb5_release_buffer(minor_status, output_message_buffer);
 439         return GSS_S_FAILURE;
 440     }
 441
 442     {
 443         int i;
 444
 445         Klocal.keytype = key->keytype;
 446         Klocal.keyvalue.data = Klocaldata;
 447         Klocal.keyvalue.length = sizeof(Klocaldata);
 448
 449         for (i = 0; i < 16; i++)
 450             Klocaldata[i] = ((u_char *)key->keyvalue.data)[i] ^ 0xF0;
 451     }
 452     ret = arcfour_mic_key(context, &Klocal,
 453                           p0 + 8, 4, /* SND_SEQ */
 454                           k6_data, sizeof(k6_data));
 455     memset(Klocaldata, 0, sizeof(Klocaldata));
 456     if (ret) {
 457         _gsskrb5_release_buffer(minor_status, output_message_buffer);
 458         *minor_status = ret;
 459         return GSS_S_FAILURE;
 460     }
 461
 462
 463     if(conf_req_flag) {
 464         EVP_CIPHER_CTX rc4_key;
 465
 466         EVP_CIPHER_CTX_init(&rc4_key);
 467         EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
 468         EVP_Cipher(&rc4_key, p0 + 24, p0 + 24, 8 + datalen);
 469         EVP_CIPHER_CTX_cleanup(&rc4_key);
 470     }
 471     memset(k6_data, 0, sizeof(k6_data));
 472
 473     ret = arcfour_mic_key(context, key,
 474                           p0 + 16, 8, /* SGN_CKSUM */
 475                           k6_data, sizeof(k6_data));
 476     if (ret) {
 477         _gsskrb5_release_buffer(minor_status, output_message_buffer);
 478         *minor_status = ret;
 479         return GSS_S_FAILURE;
 480     }
 481
 482     {
 483         EVP_CIPHER_CTX rc4_key;
 484
 485         EVP_CIPHER_CTX_init(&rc4_key);
 486         EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
 487         EVP_Cipher(&rc4_key, p0 + 8, p0 + 8 /* SND_SEQ */, 8);
 488         EVP_CIPHER_CTX_cleanup(&rc4_key);
 489         memset(k6_data, 0, sizeof(k6_data));
 490     }
 491
 492     if (conf_state)
 493         *conf_state = conf_req_flag;
 494
 495     *minor_status = 0;
 496     return GSS_S_COMPLETE;
 497 }
 498
 499 OM_uint32 _gssapi_unwrap_arcfour(OM_uint32 *minor_status,
 500                                  const gsskrb5_ctx context_handle,
 501                                  krb5_context context,
 502                                  const gss_buffer_t input_message_buffer,
 503                                  gss_buffer_t output_message_buffer,
 504                                  int *conf_state,
 505                                  gss_qop_t *qop_state,
 506                                  krb5_keyblock *key)
 507 {
 508     u_char Klocaldata[16];
 509     krb5_keyblock Klocal;
 510     krb5_error_code ret;
 511     uint32_t seq_number;
 512     size_t datalen;
 513     OM_uint32 omret;
 514     u_char k6_data[16], SND_SEQ[8], Confounder[8];
 515     u_char cksum_data[8];
 516     u_char *p, *p0;
 517     int cmp;
 518     int conf_flag;
 519     size_t padlen = 0, len;
 520
 521     if (conf_state)
 522         *conf_state = 0;
 523     if (qop_state)
 524         *qop_state = 0;
 525
 526     p0 = input_message_buffer->value;
 527
 528     if (IS_DCE_STYLE(context_handle)) {
 529         len = GSS_ARCFOUR_WRAP_TOKEN_SIZE +
 530             GSS_ARCFOUR_WRAP_TOKEN_DCE_DER_HEADER_SIZE;
 531         if (input_message_buffer->length < len)
 532             return GSS_S_BAD_MECH;
 533     } else {
 534         len = input_message_buffer->length;
 535     }
 536
 537     omret = _gssapi_verify_mech_header(&p0,
 538                                        len,
 539                                        GSS_KRB5_MECHANISM);
 540     if (omret)
 541         return omret;
 542
 543     /* length of mech header */
 544     len = (p0 - (u_char *)input_message_buffer->value) +
 545         GSS_ARCFOUR_WRAP_TOKEN_SIZE;
 546
 547     if (len > input_message_buffer->length)
 548         return GSS_S_BAD_MECH;
 549
 550     /* length of data */
 551     datalen = input_message_buffer->length - len;
 552
 553     p = p0;
 554
 555     if (memcmp(p, "\x02\x01", 2) != 0)
 556         return GSS_S_BAD_SIG;
 557     p += 2;
 558     if (memcmp(p, "\x11\x00", 2) != 0) /* SGN_ALG = HMAC MD5 ARCFOUR */
 559         return GSS_S_BAD_SIG;
 560     p += 2;
 561
 562     if (memcmp (p, "\x10\x00", 2) == 0)
 563         conf_flag = 1;
 564     else if (memcmp (p, "\xff\xff", 2) == 0)
 565         conf_flag = 0;
 566     else
 567         return GSS_S_BAD_SIG;
 568
 569     p += 2;
 570     if (memcmp (p, "\xff\xff", 2) != 0)
 571         return GSS_S_BAD_MIC;
 572     p = NULL;
 573
 574     ret = arcfour_mic_key(context, key,
 575                           p0 + 16, 8, /* SGN_CKSUM */
 576                           k6_data, sizeof(k6_data));
 577     if (ret) {
 578         *minor_status = ret;
 579         return GSS_S_FAILURE;
 580     }
 581
 582     {
 583         EVP_CIPHER_CTX rc4_key;
 584
 585         EVP_CIPHER_CTX_init(&rc4_key);
 586         EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
 587         EVP_Cipher(&rc4_key, SND_SEQ, p0 + 8, 8);
 588         EVP_CIPHER_CTX_cleanup(&rc4_key);
 589         memset(k6_data, 0, sizeof(k6_data));
 590     }
 591
 592     _gsskrb5_decode_be_om_uint32(SND_SEQ, &seq_number);
 593
 594     if (context_handle->more_flags & LOCAL)
 595         cmp = memcmp(&SND_SEQ[4], "\xff\xff\xff\xff", 4);
 596     else
 597         cmp = memcmp(&SND_SEQ[4], "\x00\x00\x00\x00", 4);
 598
 599     if (cmp != 0) {
 600         *minor_status = 0;
 601         return GSS_S_BAD_MIC;
 602     }
 603
 604     {
 605         int i;
 606
 607         Klocal.keytype = key->keytype;
 608         Klocal.keyvalue.data = Klocaldata;
 609         Klocal.keyvalue.length = sizeof(Klocaldata);
 610
 611         for (i = 0; i < 16; i++)
 612             Klocaldata[i] = ((u_char *)key->keyvalue.data)[i] ^ 0xF0;
 613     }
 614     ret = arcfour_mic_key(context, &Klocal,
 615                           SND_SEQ, 4,
 616                           k6_data, sizeof(k6_data));
 617     memset(Klocaldata, 0, sizeof(Klocaldata));
 618     if (ret) {
 619         *minor_status = ret;
 620         return GSS_S_FAILURE;
 621     }
 622
 623     output_message_buffer->value = malloc(datalen);
 624     if (output_message_buffer->value == NULL) {
 625         *minor_status = ENOMEM;
 626         return GSS_S_FAILURE;
 627     }
 628     output_message_buffer->length = datalen;
 629
 630     if(conf_flag) {
 631         EVP_CIPHER_CTX rc4_key;
 632
 633         EVP_CIPHER_CTX_init(&rc4_key);
 634         EVP_CipherInit_ex(&rc4_key, EVP_rc4(), NULL, k6_data, NULL, 1);
 635         EVP_Cipher(&rc4_key, Confounder, p0 + 24, 8);
 636         EVP_Cipher(&rc4_key, output_message_buffer->value, p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE, datalen);
 637         EVP_CIPHER_CTX_cleanup(&rc4_key);
 638     } else {
 639         memcpy(Confounder, p0 + 24, 8); /* Confounder */
 640         memcpy(output_message_buffer->value,
 641                p0 + GSS_ARCFOUR_WRAP_TOKEN_SIZE,
 642                datalen);
 643     }
 644     memset(k6_data, 0, sizeof(k6_data));
 645
 646     if (!IS_DCE_STYLE(context_handle)) {
 647         ret = _gssapi_verify_pad(output_message_buffer, datalen, &padlen);
 648         if (ret) {
 649             _gsskrb5_release_buffer(minor_status, output_message_buffer);
 650             *minor_status = 0;
 651             return ret;
 652         }
 653         output_message_buffer->length -= padlen;
 654     }
 655
 656     ret = arcfour_mic_cksum(context,
 657                             key, KRB5_KU_USAGE_SEAL,
 658                             cksum_data, sizeof(cksum_data),
 659                             p0, 8,
 660                             Confounder, sizeof(Confounder),
 661                             output_message_buffer->value,
 662                             output_message_buffer->length + padlen);
 663     if (ret) {
 664         _gsskrb5_release_buffer(minor_status, output_message_buffer);
 665         *minor_status = ret;
 666         return GSS_S_FAILURE;
 667     }
 668
 669     cmp = ct_memcmp(cksum_data, p0 + 16, 8); /* SGN_CKSUM */
 670     if (cmp) {
 671         _gsskrb5_release_buffer(minor_status, output_message_buffer);
 672         *minor_status = 0;
 673         return GSS_S_BAD_MIC;
 674     }
 675
 676     HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
 677     omret = _gssapi_msg_order_check(context_handle->order, seq_number);
 678     HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
 679     if (omret)
 680         return omret;
 681
 682     if (conf_state)
 683         *conf_state = conf_flag;
 684
 685     *minor_status = 0;
 686     return GSS_S_COMPLETE;
 687 }
 688
 689 static OM_uint32
 690 max_wrap_length_arcfour(const gsskrb5_ctx ctx,
 691                         krb5_crypto crypto,
 692                         size_t input_length,
 693                         OM_uint32 *max_input_size)
 694 {
 695     /*
 696      * if GSS_C_DCE_STYLE is in use:
 697      *  - we only need to encapsulate the WRAP token
 698      * However, since this is a fixed since, we just
 699      */
 700     if (IS_DCE_STYLE(ctx)) {
 701         size_t len, total_len;
 702
 703         len = GSS_ARCFOUR_WRAP_TOKEN_SIZE;
 704         _gssapi_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
 705
 706         if (input_length < len)
 707             *max_input_size = 0;
 708         else
 709             *max_input_size = input_length - len;
 710
 711     } else {
 712         size_t extrasize = GSS_ARCFOUR_WRAP_TOKEN_SIZE;
 713         size_t blocksize = 8;
 714         size_t len, total_len;
 715
 716         len = 8 + input_length + blocksize + extrasize;
 717
 718         _gsskrb5_encap_length(len, &len, &total_len, GSS_KRB5_MECHANISM);
 719
 720         total_len -= input_length; /* token length */
 721         if (total_len < input_length) {
 722             *max_input_size = (input_length - total_len);
 723             (*max_input_size) &= (~(OM_uint32)(blocksize - 1));
 724         } else {
 725             *max_input_size = 0;
 726         }
 727     }
 728
 729     return GSS_S_COMPLETE;
 730 }
 731
 732 OM_uint32
 733 _gssapi_wrap_size_arcfour(OM_uint32 *minor_status,
 734                           const gsskrb5_ctx ctx,
 735                           krb5_context context,
 736                           int conf_req_flag,
 737                           gss_qop_t qop_req,
 738                           OM_uint32 req_output_size,
 739                           OM_uint32 *max_input_size,
 740                           krb5_keyblock *key)
 741 {
 742     krb5_error_code ret;
 743     krb5_crypto crypto;
 744
 745     ret = krb5_crypto_init(context, key, 0, &crypto);
 746     if (ret != 0) {
 747         *minor_status = ret;
 748         return GSS_S_FAILURE;
 749     }
 750
 751     ret = max_wrap_length_arcfour(ctx, crypto,
 752                                   req_output_size, max_input_size);
 753     if (ret != 0) {
 754         *minor_status = ret;
 755         krb5_crypto_destroy(context, crypto);
 756         return GSS_S_FAILURE;
 757     }
 758
 759     krb5_crypto_destroy(context, crypto);
 760
 761     return GSS_S_COMPLETE;
 762 }