engines/e_chil.c

   1 /* crypto/engine/e_chil.c -*- mode: C; c-file-style: "eay" -*- */
   2 /*
   3  * Written by Richard Levitte (richard@levitte.org), Geoff Thorpe
   4  * (geoff@geoffthorpe.net) and Dr Stephen N Henson (steve@openssl.org) for
   5  * the OpenSSL project 2000.
   6  */
   7 /* ====================================================================
   8  * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  *
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in
  19  *    the documentation and/or other materials provided with the
  20  *    distribution.
  21  *
  22  * 3. All advertising materials mentioning features or use of this
  23  *    software must display the following acknowledgment:
  24  *    "This product includes software developed by the OpenSSL Project
  25  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  26  *
  27  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  28  *    endorse or promote products derived from this software without
  29  *    prior written permission. For written permission, please contact
  30  *    licensing@OpenSSL.org.
  31  *
  32  * 5. Products derived from this software may not be called "OpenSSL"
  33  *    nor may "OpenSSL" appear in their names without prior written
  34  *    permission of the OpenSSL Project.
  35  *
  36  * 6. Redistributions of any form whatsoever must retain the following
  37  *    acknowledgment:
  38  *    "This product includes software developed by the OpenSSL Project
  39  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  42  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  44  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  45  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  46  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  47  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  48  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  50  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  51  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  52  * OF THE POSSIBILITY OF SUCH DAMAGE.
  53  * ====================================================================
  54  *
  55  * This product includes cryptographic software written by Eric Young
  56  * (eay@cryptsoft.com).  This product includes software written by Tim
  57  * Hudson (tjh@cryptsoft.com).
  58  *
  59  */
  60
  61 #include <stdio.h>
  62 #include <string.h>
  63 #include <openssl/crypto.h>
  64 #include <openssl/pem.h>
  65 #include <openssl/dso.h>
  66 #include <openssl/engine.h>
  67 #include <openssl/ui.h>
  68 #include <openssl/rand.h>
  69 #ifndef OPENSSL_NO_RSA
  70 # include <openssl/rsa.h>
  71 #endif
  72 #ifndef OPENSSL_NO_DH
  73 # include <openssl/dh.h>
  74 #endif
  75 #include <openssl/bn.h>
  76
  77 #ifndef OPENSSL_NO_HW
  78 # ifndef OPENSSL_NO_HW_CHIL
  79
  80 /*-
  81  * Attribution notice: nCipher have said several times that it's OK for
  82  * us to implement a general interface to their boxes, and recently declared
  83  * their HWCryptoHook to be public, and therefore available for us to use.
  84  * Thanks, nCipher.
  85  *
  86  * The hwcryptohook.h included here is from May 2000.
  87  * [Richard Levitte]
  88  */
  89 #  ifdef FLAT_INC
  90 #   include "hwcryptohook.h"
  91 #  else
  92 #   include "vendor_defns/hwcryptohook.h"
  93 #  endif
  94
  95 #  define HWCRHK_LIB_NAME "CHIL engine"
  96 #  include "e_chil_err.c"
  97
  98 static int hwcrhk_destroy(ENGINE *e);
  99 static int hwcrhk_init(ENGINE *e);
 100 static int hwcrhk_finish(ENGINE *e);
 101 static int hwcrhk_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void));
 102
 103 /* Functions to handle mutexes */
 104 static int hwcrhk_mutex_init(HWCryptoHook_Mutex *,
 105                              HWCryptoHook_CallerContext *);
 106 static int hwcrhk_mutex_lock(HWCryptoHook_Mutex *);
 107 static void hwcrhk_mutex_unlock(HWCryptoHook_Mutex *);
 108 static void hwcrhk_mutex_destroy(HWCryptoHook_Mutex *);
 109
 110 /* BIGNUM stuff */
 111 static int hwcrhk_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 112                           const BIGNUM *m, BN_CTX *ctx);
 113
 114 #  ifndef OPENSSL_NO_RSA
 115 /* RSA stuff */
 116 static int hwcrhk_rsa_mod_exp(BIGNUM *r, const BIGNUM *I, RSA *rsa,
 117                               BN_CTX *ctx);
 118 /* This function is aliased to mod_exp (with the mont stuff dropped). */
 119 static int hwcrhk_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 120                                const BIGNUM *m, BN_CTX *ctx,
 121                                BN_MONT_CTX *m_ctx);
 122 static int hwcrhk_rsa_finish(RSA *rsa);
 123 #  endif
 124
 125 #  ifndef OPENSSL_NO_DH
 126 /* DH stuff */
 127 /* This function is alised to mod_exp (with the DH and mont dropped). */
 128 static int hwcrhk_mod_exp_dh(const DH *dh, BIGNUM *r,
 129                              const BIGNUM *a, const BIGNUM *p,
 130                              const BIGNUM *m, BN_CTX *ctx,
 131                              BN_MONT_CTX *m_ctx);
 132 #  endif
 133
 134 /* RAND stuff */
 135 static int hwcrhk_rand_bytes(unsigned char *buf, int num);
 136 static int hwcrhk_rand_status(void);
 137
 138 /* KM stuff */
 139 static EVP_PKEY *hwcrhk_load_privkey(ENGINE *eng, const char *key_id,
 140                                      UI_METHOD *ui_method,
 141                                      void *callback_data);
 142 static EVP_PKEY *hwcrhk_load_pubkey(ENGINE *eng, const char *key_id,
 143                                     UI_METHOD *ui_method,
 144                                     void *callback_data);
 145
 146 /* Interaction stuff */
 147 static int hwcrhk_insert_card(const char *prompt_info,
 148                               const char *wrong_info,
 149                               HWCryptoHook_PassphraseContext * ppctx,
 150                               HWCryptoHook_CallerContext * cactx);
 151 static int hwcrhk_get_pass(const char *prompt_info,
 152                            int *len_io, char *buf,
 153                            HWCryptoHook_PassphraseContext * ppctx,
 154                            HWCryptoHook_CallerContext * cactx);
 155 static void hwcrhk_log_message(void *logstr, const char *message);
 156
 157 /* The definitions for control commands specific to this engine */
 158 #  define HWCRHK_CMD_SO_PATH              ENGINE_CMD_BASE
 159 #  define HWCRHK_CMD_FORK_CHECK           (ENGINE_CMD_BASE + 1)
 160 #  define HWCRHK_CMD_THREAD_LOCKING       (ENGINE_CMD_BASE + 2)
 161 #  define HWCRHK_CMD_SET_USER_INTERFACE   (ENGINE_CMD_BASE + 3)
 162 #  define HWCRHK_CMD_SET_CALLBACK_DATA    (ENGINE_CMD_BASE + 4)
 163 static const ENGINE_CMD_DEFN hwcrhk_cmd_defns[] = {
 164     {HWCRHK_CMD_SO_PATH,
 165      "SO_PATH",
 166      "Specifies the path to the 'hwcrhk' shared library",
 167      ENGINE_CMD_FLAG_STRING},
 168     {HWCRHK_CMD_FORK_CHECK,
 169      "FORK_CHECK",
 170      "Turns fork() checking on (non-zero) or off (zero)",
 171      ENGINE_CMD_FLAG_NUMERIC},
 172     {HWCRHK_CMD_THREAD_LOCKING,
 173      "THREAD_LOCKING",
 174      "Turns thread-safe locking on (zero) or off (non-zero)",
 175      ENGINE_CMD_FLAG_NUMERIC},
 176     {HWCRHK_CMD_SET_USER_INTERFACE,
 177      "SET_USER_INTERFACE",
 178      "Set the global user interface (internal)",
 179      ENGINE_CMD_FLAG_INTERNAL},
 180     {HWCRHK_CMD_SET_CALLBACK_DATA,
 181      "SET_CALLBACK_DATA",
 182      "Set the global user interface extra data (internal)",
 183      ENGINE_CMD_FLAG_INTERNAL},
 184     {0, NULL, NULL, 0}
 185 };
 186
 187 #  ifndef OPENSSL_NO_RSA
 188 /* Our internal RSA_METHOD that we provide pointers to */
 189 static RSA_METHOD hwcrhk_rsa = {
 190     "CHIL RSA method",
 191     NULL,
 192     NULL,
 193     NULL,
 194     NULL,
 195     hwcrhk_rsa_mod_exp,
 196     hwcrhk_mod_exp_mont,
 197     NULL,
 198     hwcrhk_rsa_finish,
 199     0,
 200     NULL,
 201     NULL,
 202     NULL,
 203     NULL
 204 };
 205 #  endif
 206
 207 #  ifndef OPENSSL_NO_DH
 208 /* Our internal DH_METHOD that we provide pointers to */
 209 static DH_METHOD hwcrhk_dh = {
 210     "CHIL DH method",
 211     NULL,
 212     NULL,
 213     hwcrhk_mod_exp_dh,
 214     NULL,
 215     NULL,
 216     0,
 217     NULL,
 218     NULL
 219 };
 220 #  endif
 221
 222 static RAND_METHOD hwcrhk_rand = {
 223     /* "CHIL RAND method", */
 224     NULL,
 225     hwcrhk_rand_bytes,
 226     NULL,
 227     NULL,
 228     hwcrhk_rand_bytes,
 229     hwcrhk_rand_status,
 230 };
 231
 232 /* Constants used when creating the ENGINE */
 233 static const char *engine_hwcrhk_id = "chil";
 234 static const char *engine_hwcrhk_name = "CHIL hardware engine support";
 235 #  ifndef OPENSSL_NO_DYNAMIC_ENGINE
 236 /* Compatibility hack, the dynamic library uses this form in the path */
 237 static const char *engine_hwcrhk_id_alt = "ncipher";
 238 #  endif
 239
 240 /* Internal stuff for HWCryptoHook */
 241
 242 /* Some structures needed for proper use of thread locks */
 243 /*
 244  * hwcryptohook.h has some typedefs that turn struct HWCryptoHook_MutexValue
 245  * into HWCryptoHook_Mutex
 246  */
 247 struct HWCryptoHook_MutexValue {
 248     int lockid;
 249 };
 250
 251 /*
 252  * hwcryptohook.h has some typedefs that turn struct
 253  * HWCryptoHook_PassphraseContextValue into HWCryptoHook_PassphraseContext
 254  */
 255 struct HWCryptoHook_PassphraseContextValue {
 256     UI_METHOD *ui_method;
 257     void *callback_data;
 258 };
 259
 260 /*
 261  * hwcryptohook.h has some typedefs that turn struct
 262  * HWCryptoHook_CallerContextValue into HWCryptoHook_CallerContext
 263  */
 264 struct HWCryptoHook_CallerContextValue {
 265     pem_password_cb *password_callback; /* Deprecated! Only present for
 266                                          * backward compatibility! */
 267     UI_METHOD *ui_method;
 268     void *callback_data;
 269 };
 270
 271 /*
 272  * The MPI structure in HWCryptoHook is pretty compatible with OpenSSL
 273  * BIGNUM's, so lets define a couple of conversion macros
 274  */
 275 #  define BN2MPI(mp, bn) \
 276     {mp.size = bn->top * sizeof(BN_ULONG); mp.buf = (unsigned char *)bn->d;}
 277 #  define MPI2BN(bn, mp) \
 278     {mp.size = bn->dmax * sizeof(BN_ULONG); mp.buf = (unsigned char *)bn->d;}
 279
 280 static BIO *logstream = NULL;
 281 static int disable_mutex_callbacks = 0;
 282
 283 /*
 284  * One might wonder why these are needed, since one can pass down at least a
 285  * UI_METHOD and a pointer to callback data to the key-loading functions. The
 286  * thing is that the ModExp and RSAImmed functions can load keys as well, if
 287  * the data they get is in a special, nCipher-defined format (hint: if you
 288  * look at the private exponent of the RSA data as a string, you'll see this
 289  * string: "nCipher KM tool key id", followed by some bytes, followed a key
 290  * identity string, followed by more bytes.  This happens when you use
 291  * "embed" keys instead of "hwcrhk" keys).  Unfortunately, those functions do
 292  * not take any passphrase or caller context, and our functions can't really
 293  * take any callback data either.  Still, the "insert_card" and
 294  * "get_passphrase" callbacks may be called down the line, and will need to
 295  * know what user interface callbacks to call, and having callback data from
 296  * the application may be a nice thing as well, so we need to keep track of
 297  * that globally.
 298  */
 299 static HWCryptoHook_CallerContext password_context = { NULL, NULL, NULL };
 300
 301 /* Stuff to pass to the HWCryptoHook library */
 302 static HWCryptoHook_InitInfo hwcrhk_globals = {
 303     HWCryptoHook_InitFlags_SimpleForkCheck, /* Flags */
 304     &logstream,                 /* logstream */
 305     sizeof(BN_ULONG),           /* limbsize */
 306     0,                          /* mslimb first: false for BNs */
 307     -1,                         /* msbyte first: use native */
 308     0,                          /* Max mutexes, 0 = no small limit */
 309     0,                          /* Max simultaneous, 0 = default */
 310
 311     /*
 312      * The next few are mutex stuff: we write wrapper functions around the OS
 313      * mutex functions.  We initialise them to 0 here, and change that to
 314      * actual function pointers in hwcrhk_init() if dynamic locks are
 315      * supported (that is, if the application programmer has made sure of
 316      * setting up callbacks bafore starting this engine) *and* if
 317      * disable_mutex_callbacks hasn't been set by a call to
 318      * ENGINE_ctrl(ENGINE_CTRL_CHIL_NO_LOCKING).
 319      */
 320     sizeof(HWCryptoHook_Mutex),
 321     0,
 322     0,
 323     0,
 324     0,
 325
 326     /*
 327      * The next few are condvar stuff: we write wrapper functions round the
 328      * OS functions.  Currently not implemented and not and absolute
 329      * necessity even in threaded programs, therefore 0'ed.  Will hopefully
 330      * be implemented some day, since it enhances the efficiency of
 331      * HWCryptoHook.
 332      */
 333     0,                          /* sizeof(HWCryptoHook_CondVar), */
 334     0,                          /* hwcrhk_cv_init, */
 335     0,                          /* hwcrhk_cv_wait, */
 336     0,                          /* hwcrhk_cv_signal, */
 337     0,                          /* hwcrhk_cv_broadcast, */
 338     0,                          /* hwcrhk_cv_destroy, */
 339
 340     hwcrhk_get_pass,            /* pass phrase */
 341     hwcrhk_insert_card,         /* insert a card */
 342     hwcrhk_log_message          /* Log message */
 343 };
 344
 345 /* Now, to our own code */
 346
 347 /*
 348  * This internal function is used by ENGINE_chil() and possibly by the
 349  * "dynamic" ENGINE support too
 350  */
 351 static int bind_helper(ENGINE *e)
 352 {
 353 #  ifndef OPENSSL_NO_RSA
 354     const RSA_METHOD *meth1;
 355 #  endif
 356 #  ifndef OPENSSL_NO_DH
 357     const DH_METHOD *meth2;
 358 #  endif
 359     if (!ENGINE_set_id(e, engine_hwcrhk_id) ||
 360         !ENGINE_set_name(e, engine_hwcrhk_name) ||
 361 #  ifndef OPENSSL_NO_RSA
 362         !ENGINE_set_RSA(e, &hwcrhk_rsa) ||
 363 #  endif
 364 #  ifndef OPENSSL_NO_DH
 365         !ENGINE_set_DH(e, &hwcrhk_dh) ||
 366 #  endif
 367         !ENGINE_set_RAND(e, &hwcrhk_rand) ||
 368         !ENGINE_set_destroy_function(e, hwcrhk_destroy) ||
 369         !ENGINE_set_init_function(e, hwcrhk_init) ||
 370         !ENGINE_set_finish_function(e, hwcrhk_finish) ||
 371         !ENGINE_set_ctrl_function(e, hwcrhk_ctrl) ||
 372         !ENGINE_set_load_privkey_function(e, hwcrhk_load_privkey) ||
 373         !ENGINE_set_load_pubkey_function(e, hwcrhk_load_pubkey) ||
 374         !ENGINE_set_cmd_defns(e, hwcrhk_cmd_defns))
 375         return 0;
 376
 377 #  ifndef OPENSSL_NO_RSA
 378     /*
 379      * We know that the "PKCS1_SSLeay()" functions hook properly to the
 380      * cswift-specific mod_exp and mod_exp_crt so we use those functions. NB:
 381      * We don't use ENGINE_openssl() or anything "more generic" because
 382      * something like the RSAref code may not hook properly, and if you own
 383      * one of these cards then you have the right to do RSA operations on it
 384      * anyway!
 385      */
 386     meth1 = RSA_PKCS1_SSLeay();
 387     hwcrhk_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
 388     hwcrhk_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
 389     hwcrhk_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
 390     hwcrhk_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
 391 #  endif
 392
 393 #  ifndef OPENSSL_NO_DH
 394     /* Much the same for Diffie-Hellman */
 395     meth2 = DH_OpenSSL();
 396     hwcrhk_dh.generate_key = meth2->generate_key;
 397     hwcrhk_dh.compute_key = meth2->compute_key;
 398 #  endif
 399
 400     /* Ensure the hwcrhk error handling is set up */
 401     ERR_load_HWCRHK_strings();
 402     return 1;
 403 }
 404
 405 #  ifdef OPENSSL_NO_DYNAMIC_ENGINE
 406 static ENGINE *engine_chil(void)
 407 {
 408     ENGINE *ret = ENGINE_new();
 409     if (!ret)
 410         return NULL;
 411     if (!bind_helper(ret)) {
 412         ENGINE_free(ret);
 413         return NULL;
 414     }
 415     return ret;
 416 }
 417
 418 void ENGINE_load_chil(void)
 419 {
 420     /* Copied from eng_[openssl|dyn].c */
 421     ENGINE *toadd = engine_chil();
 422     if (!toadd)
 423         return;
 424     ENGINE_add(toadd);
 425     ENGINE_free(toadd);
 426     ERR_clear_error();
 427 }
 428 #  endif
 429
 430 /*
 431  * This is a process-global DSO handle used for loading and unloading the
 432  * HWCryptoHook library. NB: This is only set (or unset) during an init() or
 433  * finish() call (reference counts permitting) and they're operating with
 434  * global locks, so this should be thread-safe implicitly.
 435  */
 436 static DSO *hwcrhk_dso = NULL;
 437 static HWCryptoHook_ContextHandle hwcrhk_context = 0;
 438 #  ifndef OPENSSL_NO_RSA
 439 /* Index for KM handle.  Not really used yet. */
 440 static int hndidx_rsa = -1;
 441 #  endif
 442
 443 /*
 444  * These are the function pointers that are (un)set when the library has
 445  * successfully (un)loaded.
 446  */
 447 static HWCryptoHook_Init_t *p_hwcrhk_Init = NULL;
 448 static HWCryptoHook_Finish_t *p_hwcrhk_Finish = NULL;
 449 static HWCryptoHook_ModExp_t *p_hwcrhk_ModExp = NULL;
 450 #  ifndef OPENSSL_NO_RSA
 451 static HWCryptoHook_RSA_t *p_hwcrhk_RSA = NULL;
 452 #  endif
 453 static HWCryptoHook_RandomBytes_t *p_hwcrhk_RandomBytes = NULL;
 454 #  ifndef OPENSSL_NO_RSA
 455 static HWCryptoHook_RSALoadKey_t *p_hwcrhk_RSALoadKey = NULL;
 456 static HWCryptoHook_RSAGetPublicKey_t *p_hwcrhk_RSAGetPublicKey = NULL;
 457 static HWCryptoHook_RSAUnloadKey_t *p_hwcrhk_RSAUnloadKey = NULL;
 458 #  endif
 459 static HWCryptoHook_ModExpCRT_t *p_hwcrhk_ModExpCRT = NULL;
 460
 461 /* Used in the DSO operations. */
 462 static const char *HWCRHK_LIBNAME = NULL;
 463 static void free_HWCRHK_LIBNAME(void)
 464 {
 465     if (HWCRHK_LIBNAME)
 466         OPENSSL_free((void *)HWCRHK_LIBNAME);
 467     HWCRHK_LIBNAME = NULL;
 468 }
 469
 470 static const char *get_HWCRHK_LIBNAME(void)
 471 {
 472     if (HWCRHK_LIBNAME)
 473         return HWCRHK_LIBNAME;
 474     return "nfhwcrhk";
 475 }
 476
 477 static long set_HWCRHK_LIBNAME(const char *name)
 478 {
 479     free_HWCRHK_LIBNAME();
 480     return (((HWCRHK_LIBNAME = BUF_strdup(name)) != NULL) ? 1 : 0);
 481 }
 482
 483 static const char *n_hwcrhk_Init = "HWCryptoHook_Init";
 484 static const char *n_hwcrhk_Finish = "HWCryptoHook_Finish";
 485 static const char *n_hwcrhk_ModExp = "HWCryptoHook_ModExp";
 486 #  ifndef OPENSSL_NO_RSA
 487 static const char *n_hwcrhk_RSA = "HWCryptoHook_RSA";
 488 #  endif
 489 static const char *n_hwcrhk_RandomBytes = "HWCryptoHook_RandomBytes";
 490 #  ifndef OPENSSL_NO_RSA
 491 static const char *n_hwcrhk_RSALoadKey = "HWCryptoHook_RSALoadKey";
 492 static const char *n_hwcrhk_RSAGetPublicKey = "HWCryptoHook_RSAGetPublicKey";
 493 static const char *n_hwcrhk_RSAUnloadKey = "HWCryptoHook_RSAUnloadKey";
 494 #  endif
 495 static const char *n_hwcrhk_ModExpCRT = "HWCryptoHook_ModExpCRT";
 496
 497 /*
 498  * HWCryptoHook library functions and mechanics - these are used by the
 499  * higher-level functions further down. NB: As and where there's no error
 500  * checking, take a look lower down where these functions are called, the
 501  * checking and error handling is probably down there.
 502  */
 503
 504 /* utility function to obtain a context */
 505 static int get_context(HWCryptoHook_ContextHandle * hac,
 506                        HWCryptoHook_CallerContext * cac)
 507 {
 508     char tempbuf[1024];
 509     HWCryptoHook_ErrMsgBuf rmsg;
 510
 511     rmsg.buf = tempbuf;
 512     rmsg.size = sizeof(tempbuf);
 513
 514     *hac = p_hwcrhk_Init(&hwcrhk_globals, sizeof(hwcrhk_globals), &rmsg, cac);
 515     if (!*hac)
 516         return 0;
 517     return 1;
 518 }
 519
 520 /* similarly to release one. */
 521 static void release_context(HWCryptoHook_ContextHandle hac)
 522 {
 523     p_hwcrhk_Finish(hac);
 524 }
 525
 526 /* Destructor (complements the "ENGINE_chil()" constructor) */
 527 static int hwcrhk_destroy(ENGINE *e)
 528 {
 529     free_HWCRHK_LIBNAME();
 530     ERR_unload_HWCRHK_strings();
 531     return 1;
 532 }
 533
 534 /* (de)initialisation functions. */
 535 static int hwcrhk_init(ENGINE *e)
 536 {
 537     HWCryptoHook_Init_t *p1;
 538     HWCryptoHook_Finish_t *p2;
 539     HWCryptoHook_ModExp_t *p3;
 540 #  ifndef OPENSSL_NO_RSA
 541     HWCryptoHook_RSA_t *p4;
 542     HWCryptoHook_RSALoadKey_t *p5;
 543     HWCryptoHook_RSAGetPublicKey_t *p6;
 544     HWCryptoHook_RSAUnloadKey_t *p7;
 545 #  endif
 546     HWCryptoHook_RandomBytes_t *p8;
 547     HWCryptoHook_ModExpCRT_t *p9;
 548
 549     if (hwcrhk_dso != NULL) {
 550         HWCRHKerr(HWCRHK_F_HWCRHK_INIT, HWCRHK_R_ALREADY_LOADED);
 551         goto err;
 552     }
 553     /* Attempt to load libnfhwcrhk.so/nfhwcrhk.dll/whatever. */
 554     hwcrhk_dso = DSO_load(NULL, get_HWCRHK_LIBNAME(), NULL, 0);
 555     if (hwcrhk_dso == NULL) {
 556         HWCRHKerr(HWCRHK_F_HWCRHK_INIT, HWCRHK_R_DSO_FAILURE);
 557         goto err;
 558     }
 559     if (!(p1 = (HWCryptoHook_Init_t *)
 560           DSO_bind_func(hwcrhk_dso, n_hwcrhk_Init)) ||
 561         !(p2 = (HWCryptoHook_Finish_t *)
 562           DSO_bind_func(hwcrhk_dso, n_hwcrhk_Finish)) ||
 563         !(p3 = (HWCryptoHook_ModExp_t *)
 564           DSO_bind_func(hwcrhk_dso, n_hwcrhk_ModExp)) ||
 565 #  ifndef OPENSSL_NO_RSA
 566         !(p4 = (HWCryptoHook_RSA_t *)
 567           DSO_bind_func(hwcrhk_dso, n_hwcrhk_RSA)) ||
 568         !(p5 = (HWCryptoHook_RSALoadKey_t *)
 569           DSO_bind_func(hwcrhk_dso, n_hwcrhk_RSALoadKey)) ||
 570         !(p6 = (HWCryptoHook_RSAGetPublicKey_t *)
 571           DSO_bind_func(hwcrhk_dso, n_hwcrhk_RSAGetPublicKey)) ||
 572         !(p7 = (HWCryptoHook_RSAUnloadKey_t *)
 573           DSO_bind_func(hwcrhk_dso, n_hwcrhk_RSAUnloadKey)) ||
 574 #  endif
 575         !(p8 = (HWCryptoHook_RandomBytes_t *)
 576           DSO_bind_func(hwcrhk_dso, n_hwcrhk_RandomBytes)) ||
 577         !(p9 = (HWCryptoHook_ModExpCRT_t *)
 578           DSO_bind_func(hwcrhk_dso, n_hwcrhk_ModExpCRT))) {
 579         HWCRHKerr(HWCRHK_F_HWCRHK_INIT, HWCRHK_R_DSO_FAILURE);
 580         goto err;
 581     }
 582     /* Copy the pointers */
 583     p_hwcrhk_Init = p1;
 584     p_hwcrhk_Finish = p2;
 585     p_hwcrhk_ModExp = p3;
 586 #  ifndef OPENSSL_NO_RSA
 587     p_hwcrhk_RSA = p4;
 588     p_hwcrhk_RSALoadKey = p5;
 589     p_hwcrhk_RSAGetPublicKey = p6;
 590     p_hwcrhk_RSAUnloadKey = p7;
 591 #  endif
 592     p_hwcrhk_RandomBytes = p8;
 593     p_hwcrhk_ModExpCRT = p9;
 594
 595     /*
 596      * Check if the application decided to support dynamic locks, and if it
 597      * does, use them.
 598      */
 599     if (disable_mutex_callbacks == 0) {
 600         if (CRYPTO_get_dynlock_create_callback() != NULL &&
 601             CRYPTO_get_dynlock_lock_callback() != NULL &&
 602             CRYPTO_get_dynlock_destroy_callback() != NULL) {
 603             hwcrhk_globals.mutex_init = hwcrhk_mutex_init;
 604             hwcrhk_globals.mutex_acquire = hwcrhk_mutex_lock;
 605             hwcrhk_globals.mutex_release = hwcrhk_mutex_unlock;
 606             hwcrhk_globals.mutex_destroy = hwcrhk_mutex_destroy;
 607         }
 608     }
 609
 610     /*
 611      * Try and get a context - if not, we may have a DSO but no accelerator!
 612      */
 613     if (!get_context(&hwcrhk_context, &password_context)) {
 614         HWCRHKerr(HWCRHK_F_HWCRHK_INIT, HWCRHK_R_UNIT_FAILURE);
 615         goto err;
 616     }
 617     /* Everything's fine. */
 618 #  ifndef OPENSSL_NO_RSA
 619     if (hndidx_rsa == -1)
 620         hndidx_rsa = RSA_get_ex_new_index(0,
 621                                           "nFast HWCryptoHook RSA key handle",
 622                                           NULL, NULL, NULL);
 623 #  endif
 624     return 1;
 625  err:
 626     if (hwcrhk_dso)
 627         DSO_free(hwcrhk_dso);
 628     hwcrhk_dso = NULL;
 629     p_hwcrhk_Init = NULL;
 630     p_hwcrhk_Finish = NULL;
 631     p_hwcrhk_ModExp = NULL;
 632 #  ifndef OPENSSL_NO_RSA
 633     p_hwcrhk_RSA = NULL;
 634     p_hwcrhk_RSALoadKey = NULL;
 635     p_hwcrhk_RSAGetPublicKey = NULL;
 636     p_hwcrhk_RSAUnloadKey = NULL;
 637 #  endif
 638     p_hwcrhk_ModExpCRT = NULL;
 639     p_hwcrhk_RandomBytes = NULL;
 640     return 0;
 641 }
 642
 643 static int hwcrhk_finish(ENGINE *e)
 644 {
 645     int to_return = 1;
 646     free_HWCRHK_LIBNAME();
 647     if (hwcrhk_dso == NULL) {
 648         HWCRHKerr(HWCRHK_F_HWCRHK_FINISH, HWCRHK_R_NOT_LOADED);
 649         to_return = 0;
 650         goto err;
 651     }
 652     release_context(hwcrhk_context);
 653     if (!DSO_free(hwcrhk_dso)) {
 654         HWCRHKerr(HWCRHK_F_HWCRHK_FINISH, HWCRHK_R_DSO_FAILURE);
 655         to_return = 0;
 656         goto err;
 657     }
 658  err:
 659     if (logstream)
 660         BIO_free(logstream);
 661     hwcrhk_dso = NULL;
 662     p_hwcrhk_Init = NULL;
 663     p_hwcrhk_Finish = NULL;
 664     p_hwcrhk_ModExp = NULL;
 665 #  ifndef OPENSSL_NO_RSA
 666     p_hwcrhk_RSA = NULL;
 667     p_hwcrhk_RSALoadKey = NULL;
 668     p_hwcrhk_RSAGetPublicKey = NULL;
 669     p_hwcrhk_RSAUnloadKey = NULL;
 670 #  endif
 671     p_hwcrhk_ModExpCRT = NULL;
 672     p_hwcrhk_RandomBytes = NULL;
 673     return to_return;
 674 }
 675
 676 static int hwcrhk_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
 677 {
 678     int to_return = 1;
 679
 680     switch (cmd) {
 681     case HWCRHK_CMD_SO_PATH:
 682         if (hwcrhk_dso) {
 683             HWCRHKerr(HWCRHK_F_HWCRHK_CTRL, HWCRHK_R_ALREADY_LOADED);
 684             return 0;
 685         }
 686         if (p == NULL) {
 687             HWCRHKerr(HWCRHK_F_HWCRHK_CTRL, ERR_R_PASSED_NULL_PARAMETER);
 688             return 0;
 689         }
 690         return set_HWCRHK_LIBNAME((const char *)p);
 691     case ENGINE_CTRL_SET_LOGSTREAM:
 692         {
 693             BIO *bio = (BIO *)p;
 694
 695             CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 696             if (logstream) {
 697                 BIO_free(logstream);
 698                 logstream = NULL;
 699             }
 700             if (CRYPTO_add(&bio->references, 1, CRYPTO_LOCK_BIO) > 1)
 701                 logstream = bio;
 702             else
 703                 HWCRHKerr(HWCRHK_F_HWCRHK_CTRL, HWCRHK_R_BIO_WAS_FREED);
 704         }
 705         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 706         break;
 707     case ENGINE_CTRL_SET_PASSWORD_CALLBACK:
 708         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 709         password_context.password_callback = (pem_password_cb *)f;
 710         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 711         break;
 712     case ENGINE_CTRL_SET_USER_INTERFACE:
 713     case HWCRHK_CMD_SET_USER_INTERFACE:
 714         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 715         password_context.ui_method = (UI_METHOD *)p;
 716         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 717         break;
 718     case ENGINE_CTRL_SET_CALLBACK_DATA:
 719     case HWCRHK_CMD_SET_CALLBACK_DATA:
 720         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 721         password_context.callback_data = p;
 722         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 723         break;
 724         /*
 725          * this enables or disables the "SimpleForkCheck" flag used in the
 726          * initialisation structure.
 727          */
 728     case ENGINE_CTRL_CHIL_SET_FORKCHECK:
 729     case HWCRHK_CMD_FORK_CHECK:
 730         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 731         if (i)
 732             hwcrhk_globals.flags |= HWCryptoHook_InitFlags_SimpleForkCheck;
 733         else
 734             hwcrhk_globals.flags &= ~HWCryptoHook_InitFlags_SimpleForkCheck;
 735         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 736         break;
 737         /*
 738          * This will prevent the initialisation function from "installing"
 739          * the mutex-handling callbacks, even if they are available from
 740          * within the library (or were provided to the library from the
 741          * calling application). This is to remove any baggage for
 742          * applications not using multithreading.
 743          */
 744     case ENGINE_CTRL_CHIL_NO_LOCKING:
 745         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 746         disable_mutex_callbacks = 1;
 747         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 748         break;
 749     case HWCRHK_CMD_THREAD_LOCKING:
 750         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 751         disable_mutex_callbacks = ((i == 0) ? 0 : 1);
 752         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 753         break;
 754
 755         /* The command isn't understood by this engine */
 756     default:
 757         HWCRHKerr(HWCRHK_F_HWCRHK_CTRL,
 758                   HWCRHK_R_CTRL_COMMAND_NOT_IMPLEMENTED);
 759         to_return = 0;
 760         break;
 761     }
 762
 763     return to_return;
 764 }
 765
 766 static EVP_PKEY *hwcrhk_load_privkey(ENGINE *eng, const char *key_id,
 767                                      UI_METHOD *ui_method,
 768                                      void *callback_data)
 769 {
 770 #  ifndef OPENSSL_NO_RSA
 771     RSA *rtmp = NULL;
 772 #  endif
 773     EVP_PKEY *res = NULL;
 774 #  ifndef OPENSSL_NO_RSA
 775     HWCryptoHook_MPI e, n;
 776     HWCryptoHook_RSAKeyHandle *hptr;
 777 #  endif
 778 #  if !defined(OPENSSL_NO_RSA)
 779     char tempbuf[1024];
 780     HWCryptoHook_ErrMsgBuf rmsg;
 781     HWCryptoHook_PassphraseContext ppctx;
 782 #  endif
 783
 784 #  if !defined(OPENSSL_NO_RSA)
 785     rmsg.buf = tempbuf;
 786     rmsg.size = sizeof(tempbuf);
 787 #  endif
 788
 789     if (!hwcrhk_context) {
 790         HWCRHKerr(HWCRHK_F_HWCRHK_LOAD_PRIVKEY, HWCRHK_R_NOT_INITIALISED);
 791         goto err;
 792     }
 793 #  ifndef OPENSSL_NO_RSA
 794     hptr = OPENSSL_malloc(sizeof(HWCryptoHook_RSAKeyHandle));
 795     if (!hptr) {
 796         HWCRHKerr(HWCRHK_F_HWCRHK_LOAD_PRIVKEY, ERR_R_MALLOC_FAILURE);
 797         goto err;
 798     }
 799     ppctx.ui_method = ui_method;
 800     ppctx.callback_data = callback_data;
 801     if (p_hwcrhk_RSALoadKey(hwcrhk_context, key_id, hptr, &rmsg, &ppctx)) {
 802         HWCRHKerr(HWCRHK_F_HWCRHK_LOAD_PRIVKEY, HWCRHK_R_CHIL_ERROR);
 803         ERR_add_error_data(1, rmsg.buf);
 804         goto err;
 805     }
 806     if (!*hptr) {
 807         HWCRHKerr(HWCRHK_F_HWCRHK_LOAD_PRIVKEY, HWCRHK_R_NO_KEY);
 808         goto err;
 809     }
 810 #  endif
 811 #  ifndef OPENSSL_NO_RSA
 812     rtmp = RSA_new_method(eng);
 813     RSA_set_ex_data(rtmp, hndidx_rsa, (char *)hptr);
 814     rtmp->e = BN_new();
 815     rtmp->n = BN_new();
 816     rtmp->flags |= RSA_FLAG_EXT_PKEY;
 817     MPI2BN(rtmp->e, e);
 818     MPI2BN(rtmp->n, n);
 819     if (p_hwcrhk_RSAGetPublicKey(*hptr, &n, &e, &rmsg)
 820         != HWCRYPTOHOOK_ERROR_MPISIZE) {
 821         HWCRHKerr(HWCRHK_F_HWCRHK_LOAD_PRIVKEY, HWCRHK_R_CHIL_ERROR);
 822         ERR_add_error_data(1, rmsg.buf);
 823         goto err;
 824     }
 825
 826     bn_expand2(rtmp->e, e.size / sizeof(BN_ULONG));
 827     bn_expand2(rtmp->n, n.size / sizeof(BN_ULONG));
 828     MPI2BN(rtmp->e, e);
 829     MPI2BN(rtmp->n, n);
 830
 831     if (p_hwcrhk_RSAGetPublicKey(*hptr, &n, &e, &rmsg)) {
 832         HWCRHKerr(HWCRHK_F_HWCRHK_LOAD_PRIVKEY, HWCRHK_R_CHIL_ERROR);
 833         ERR_add_error_data(1, rmsg.buf);
 834         goto err;
 835     }
 836     rtmp->e->top = e.size / sizeof(BN_ULONG);
 837     bn_fix_top(rtmp->e);
 838     rtmp->n->top = n.size / sizeof(BN_ULONG);
 839     bn_fix_top(rtmp->n);
 840
 841     res = EVP_PKEY_new();
 842     EVP_PKEY_assign_RSA(res, rtmp);
 843 #  endif
 844
 845     if (!res)
 846         HWCRHKerr(HWCRHK_F_HWCRHK_LOAD_PRIVKEY,
 847                   HWCRHK_R_PRIVATE_KEY_ALGORITHMS_DISABLED);
 848
 849     return res;
 850  err:
 851 #  ifndef OPENSSL_NO_RSA
 852     if (rtmp)
 853         RSA_free(rtmp);
 854 #  endif
 855     return NULL;
 856 }
 857
 858 static EVP_PKEY *hwcrhk_load_pubkey(ENGINE *eng, const char *key_id,
 859                                     UI_METHOD *ui_method, void *callback_data)
 860 {
 861     EVP_PKEY *res = NULL;
 862
 863 #  ifndef OPENSSL_NO_RSA
 864     res = hwcrhk_load_privkey(eng, key_id, ui_method, callback_data);
 865 #  endif
 866
 867     if (res)
 868         switch (res->type) {
 869 #  ifndef OPENSSL_NO_RSA
 870         case EVP_PKEY_RSA:
 871             {
 872                 RSA *rsa = NULL;
 873
 874                 CRYPTO_w_lock(CRYPTO_LOCK_EVP_PKEY);
 875                 rsa = res->pkey.rsa;
 876                 res->pkey.rsa = RSA_new();
 877                 res->pkey.rsa->n = rsa->n;
 878                 res->pkey.rsa->e = rsa->e;
 879                 rsa->n = NULL;
 880                 rsa->e = NULL;
 881                 CRYPTO_w_unlock(CRYPTO_LOCK_EVP_PKEY);
 882                 RSA_free(rsa);
 883             }
 884             break;
 885 #  endif
 886         default:
 887             HWCRHKerr(HWCRHK_F_HWCRHK_LOAD_PUBKEY,
 888                       HWCRHK_R_CTRL_COMMAND_NOT_IMPLEMENTED);
 889             goto err;
 890         }
 891
 892     return res;
 893  err:
 894     if (res)
 895         EVP_PKEY_free(res);
 896     return NULL;
 897 }
 898
 899 /* A little mod_exp */
 900 static int hwcrhk_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 901                           const BIGNUM *m, BN_CTX *ctx)
 902 {
 903     char tempbuf[1024];
 904     HWCryptoHook_ErrMsgBuf rmsg;
 905     /*
 906      * Since HWCryptoHook_MPI is pretty compatible with BIGNUM's, we use them
 907      * directly, plus a little macro magic.  We only thing we need to make
 908      * sure of is that enough space is allocated.
 909      */
 910     HWCryptoHook_MPI m_a, m_p, m_n, m_r;
 911     int to_return, ret;
 912
 913     to_return = 0;              /* expect failure */
 914     rmsg.buf = tempbuf;
 915     rmsg.size = sizeof(tempbuf);
 916
 917     if (!hwcrhk_context) {
 918         HWCRHKerr(HWCRHK_F_HWCRHK_MOD_EXP, HWCRHK_R_NOT_INITIALISED);
 919         goto err;
 920     }
 921     /* Prepare the params */
 922     bn_expand2(r, m->top);      /* Check for error !! */
 923     BN2MPI(m_a, a);
 924     BN2MPI(m_p, p);
 925     BN2MPI(m_n, m);
 926     MPI2BN(r, m_r);
 927
 928     /* Perform the operation */
 929     ret = p_hwcrhk_ModExp(hwcrhk_context, m_a, m_p, m_n, &m_r, &rmsg);
 930
 931     /* Convert the response */
 932     r->top = m_r.size / sizeof(BN_ULONG);
 933     bn_fix_top(r);
 934
 935     if (ret < 0) {
 936         /*
 937          * FIXME: When this error is returned, HWCryptoHook is telling us
 938          * that falling back to software computation might be a good thing.
 939          */
 940         if (ret == HWCRYPTOHOOK_ERROR_FALLBACK) {
 941             HWCRHKerr(HWCRHK_F_HWCRHK_MOD_EXP, HWCRHK_R_REQUEST_FALLBACK);
 942         } else {
 943             HWCRHKerr(HWCRHK_F_HWCRHK_MOD_EXP, HWCRHK_R_REQUEST_FAILED);
 944         }
 945         ERR_add_error_data(1, rmsg.buf);
 946         goto err;
 947     }
 948
 949     to_return = 1;
 950  err:
 951     return to_return;
 952 }
 953
 954 #  ifndef OPENSSL_NO_RSA
 955 static int hwcrhk_rsa_mod_exp(BIGNUM *r, const BIGNUM *I, RSA *rsa,
 956                               BN_CTX *ctx)
 957 {
 958     char tempbuf[1024];
 959     HWCryptoHook_ErrMsgBuf rmsg;
 960     HWCryptoHook_RSAKeyHandle *hptr;
 961     int to_return = 0, ret;
 962
 963     rmsg.buf = tempbuf;
 964     rmsg.size = sizeof(tempbuf);
 965
 966     if (!hwcrhk_context) {
 967         HWCRHKerr(HWCRHK_F_HWCRHK_RSA_MOD_EXP, HWCRHK_R_NOT_INITIALISED);
 968         goto err;
 969     }
 970
 971     /*
 972      * This provides support for nForce keys.  Since that's opaque data all
 973      * we do is provide a handle to the proper key and let HWCryptoHook take
 974      * care of the rest.
 975      */
 976     if ((hptr =
 977          (HWCryptoHook_RSAKeyHandle *) RSA_get_ex_data(rsa, hndidx_rsa))
 978         != NULL) {
 979         HWCryptoHook_MPI m_a, m_r;
 980
 981         if (!rsa->n) {
 982             HWCRHKerr(HWCRHK_F_HWCRHK_RSA_MOD_EXP,
 983                       HWCRHK_R_MISSING_KEY_COMPONENTS);
 984             goto err;
 985         }
 986
 987         /* Prepare the params */
 988         bn_expand2(r, rsa->n->top); /* Check for error !! */
 989         BN2MPI(m_a, I);
 990         MPI2BN(r, m_r);
 991
 992         /* Perform the operation */
 993         ret = p_hwcrhk_RSA(m_a, *hptr, &m_r, &rmsg);
 994
 995         /* Convert the response */
 996         r->top = m_r.size / sizeof(BN_ULONG);
 997         bn_fix_top(r);
 998
 999         if (ret < 0) {
1000             /*
1001              * FIXME: When this error is returned, HWCryptoHook is telling us
1002              * that falling back to software computation might be a good
1003              * thing.
1004              */
1005             if (ret == HWCRYPTOHOOK_ERROR_FALLBACK) {
1006                 HWCRHKerr(HWCRHK_F_HWCRHK_RSA_MOD_EXP,
1007                           HWCRHK_R_REQUEST_FALLBACK);
1008             } else {
1009                 HWCRHKerr(HWCRHK_F_HWCRHK_RSA_MOD_EXP,
1010                           HWCRHK_R_REQUEST_FAILED);
1011             }
1012             ERR_add_error_data(1, rmsg.buf);
1013             goto err;
1014         }
1015     } else {
1016         HWCryptoHook_MPI m_a, m_p, m_q, m_dmp1, m_dmq1, m_iqmp, m_r;
1017
1018         if (!rsa->p || !rsa->q || !rsa->dmp1 || !rsa->dmq1 || !rsa->iqmp) {
1019             HWCRHKerr(HWCRHK_F_HWCRHK_RSA_MOD_EXP,
1020                       HWCRHK_R_MISSING_KEY_COMPONENTS);
1021             goto err;
1022         }
1023
1024         /* Prepare the params */
1025         bn_expand2(r, rsa->n->top); /* Check for error !! */
1026         BN2MPI(m_a, I);
1027         BN2MPI(m_p, rsa->p);
1028         BN2MPI(m_q, rsa->q);
1029         BN2MPI(m_dmp1, rsa->dmp1);
1030         BN2MPI(m_dmq1, rsa->dmq1);
1031         BN2MPI(m_iqmp, rsa->iqmp);
1032         MPI2BN(r, m_r);
1033
1034         /* Perform the operation */
1035         ret = p_hwcrhk_ModExpCRT(hwcrhk_context, m_a, m_p, m_q,
1036                                  m_dmp1, m_dmq1, m_iqmp, &m_r, &rmsg);
1037
1038         /* Convert the response */
1039         r->top = m_r.size / sizeof(BN_ULONG);
1040         bn_fix_top(r);
1041
1042         if (ret < 0) {
1043             /*
1044              * FIXME: When this error is returned, HWCryptoHook is telling us
1045              * that falling back to software computation might be a good
1046              * thing.
1047              */
1048             if (ret == HWCRYPTOHOOK_ERROR_FALLBACK) {
1049                 HWCRHKerr(HWCRHK_F_HWCRHK_RSA_MOD_EXP,
1050                           HWCRHK_R_REQUEST_FALLBACK);
1051             } else {
1052                 HWCRHKerr(HWCRHK_F_HWCRHK_RSA_MOD_EXP,
1053                           HWCRHK_R_REQUEST_FAILED);
1054             }
1055             ERR_add_error_data(1, rmsg.buf);
1056             goto err;
1057         }
1058     }
1059     /*
1060      * If we're here, we must be here with some semblance of success :-)
1061      */
1062     to_return = 1;
1063  err:
1064     return to_return;
1065 }
1066 #  endif
1067
1068 #  ifndef OPENSSL_NO_RSA
1069 /* This function is aliased to mod_exp (with the mont stuff dropped). */
1070 static int hwcrhk_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
1071                                const BIGNUM *m, BN_CTX *ctx,
1072                                BN_MONT_CTX *m_ctx)
1073 {
1074     return hwcrhk_mod_exp(r, a, p, m, ctx);
1075 }
1076
1077 static int hwcrhk_rsa_finish(RSA *rsa)
1078 {
1079     HWCryptoHook_RSAKeyHandle *hptr;
1080
1081     hptr = RSA_get_ex_data(rsa, hndidx_rsa);
1082     if (hptr) {
1083         p_hwcrhk_RSAUnloadKey(*hptr, NULL);
1084         OPENSSL_free(hptr);
1085         RSA_set_ex_data(rsa, hndidx_rsa, NULL);
1086     }
1087     return 1;
1088 }
1089
1090 #  endif
1091
1092 #  ifndef OPENSSL_NO_DH
1093 /* This function is aliased to mod_exp (with the dh and mont dropped). */
1094 static int hwcrhk_mod_exp_dh(const DH *dh, BIGNUM *r,
1095                              const BIGNUM *a, const BIGNUM *p,
1096                              const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
1097 {
1098     return hwcrhk_mod_exp(r, a, p, m, ctx);
1099 }
1100 #  endif
1101
1102 /* Random bytes are good */
1103 static int hwcrhk_rand_bytes(unsigned char *buf, int num)
1104 {
1105     char tempbuf[1024];
1106     HWCryptoHook_ErrMsgBuf rmsg;
1107     int to_return = 0;          /* assume failure */
1108     int ret;
1109
1110     rmsg.buf = tempbuf;
1111     rmsg.size = sizeof(tempbuf);
1112
1113     if (!hwcrhk_context) {
1114         HWCRHKerr(HWCRHK_F_HWCRHK_RAND_BYTES, HWCRHK_R_NOT_INITIALISED);
1115         goto err;
1116     }
1117
1118     ret = p_hwcrhk_RandomBytes(hwcrhk_context, buf, num, &rmsg);
1119     if (ret < 0) {
1120         /*
1121          * FIXME: When this error is returned, HWCryptoHook is telling us
1122          * that falling back to software computation might be a good thing.
1123          */
1124         if (ret == HWCRYPTOHOOK_ERROR_FALLBACK) {
1125             HWCRHKerr(HWCRHK_F_HWCRHK_RAND_BYTES, HWCRHK_R_REQUEST_FALLBACK);
1126         } else {
1127             HWCRHKerr(HWCRHK_F_HWCRHK_RAND_BYTES, HWCRHK_R_REQUEST_FAILED);
1128         }
1129         ERR_add_error_data(1, rmsg.buf);
1130         goto err;
1131     }
1132     to_return = 1;
1133  err:
1134     return to_return;
1135 }
1136
1137 static int hwcrhk_rand_status(void)
1138 {
1139     return 1;
1140 }
1141
1142 /*
1143  * Mutex calls: since the HWCryptoHook model closely follows the POSIX model
1144  * these just wrap the POSIX functions and add some logging.
1145  */
1146
1147 static int hwcrhk_mutex_init(HWCryptoHook_Mutex * mt,
1148                              HWCryptoHook_CallerContext * cactx)
1149 {
1150     mt->lockid = CRYPTO_get_new_dynlockid();
1151     if (mt->lockid == 0)
1152         return 1;               /* failure */
1153     return 0;                   /* success */
1154 }
1155
1156 static int hwcrhk_mutex_lock(HWCryptoHook_Mutex * mt)
1157 {
1158     CRYPTO_w_lock(mt->lockid);
1159     return 0;
1160 }
1161
1162 static void hwcrhk_mutex_unlock(HWCryptoHook_Mutex * mt)
1163 {
1164     CRYPTO_w_unlock(mt->lockid);
1165 }
1166
1167 static void hwcrhk_mutex_destroy(HWCryptoHook_Mutex * mt)
1168 {
1169     CRYPTO_destroy_dynlockid(mt->lockid);
1170 }
1171
1172 static int hwcrhk_get_pass(const char *prompt_info,
1173                            int *len_io, char *buf,
1174                            HWCryptoHook_PassphraseContext * ppctx,
1175                            HWCryptoHook_CallerContext * cactx)
1176 {
1177     pem_password_cb *callback = NULL;
1178     void *callback_data = NULL;
1179     UI_METHOD *ui_method = NULL;
1180     /*
1181      * Despite what the documentation says prompt_info can be an empty
1182      * string.
1183      */
1184     if (prompt_info && !*prompt_info)
1185         prompt_info = NULL;
1186
1187     if (cactx) {
1188         if (cactx->ui_method)
1189             ui_method = cactx->ui_method;
1190         if (cactx->password_callback)
1191             callback = cactx->password_callback;
1192         if (cactx->callback_data)
1193             callback_data = cactx->callback_data;
1194     }
1195     if (ppctx) {
1196         if (ppctx->ui_method) {
1197             ui_method = ppctx->ui_method;
1198             callback = NULL;
1199         }
1200         if (ppctx->callback_data)
1201             callback_data = ppctx->callback_data;
1202     }
1203     if (callback == NULL && ui_method == NULL) {
1204         HWCRHKerr(HWCRHK_F_HWCRHK_GET_PASS, HWCRHK_R_NO_CALLBACK);
1205         return -1;
1206     }
1207
1208     if (ui_method) {
1209         UI *ui = UI_new_method(ui_method);
1210         if (ui) {
1211             int ok;
1212             char *prompt = UI_construct_prompt(ui,
1213                                                "pass phrase", prompt_info);
1214
1215             ok = UI_add_input_string(ui, prompt,
1216                                      UI_INPUT_FLAG_DEFAULT_PWD,
1217                                      buf, 0, (*len_io) - 1);
1218             UI_add_user_data(ui, callback_data);
1219             UI_ctrl(ui, UI_CTRL_PRINT_ERRORS, 1, 0, 0);
1220
1221             if (ok >= 0)
1222                 do {
1223                     ok = UI_process(ui);
1224                 }
1225                 while (ok < 0 && UI_ctrl(ui, UI_CTRL_IS_REDOABLE, 0, 0, 0));
1226
1227             if (ok >= 0)
1228                 *len_io = strlen(buf);
1229
1230             UI_free(ui);
1231             OPENSSL_free(prompt);
1232         }
1233     } else {
1234         *len_io = callback(buf, *len_io, 0, callback_data);
1235     }
1236     if (!*len_io)
1237         return -1;
1238     return 0;
1239 }
1240
1241 static int hwcrhk_insert_card(const char *prompt_info,
1242                               const char *wrong_info,
1243                               HWCryptoHook_PassphraseContext * ppctx,
1244                               HWCryptoHook_CallerContext * cactx)
1245 {
1246     int ok = -1;
1247     UI *ui;
1248     void *callback_data = NULL;
1249     UI_METHOD *ui_method = NULL;
1250
1251     if (cactx) {
1252         if (cactx->ui_method)
1253             ui_method = cactx->ui_method;
1254         if (cactx->callback_data)
1255             callback_data = cactx->callback_data;
1256     }
1257     if (ppctx) {
1258         if (ppctx->ui_method)
1259             ui_method = ppctx->ui_method;
1260         if (ppctx->callback_data)
1261             callback_data = ppctx->callback_data;
1262     }
1263     if (ui_method == NULL) {
1264         HWCRHKerr(HWCRHK_F_HWCRHK_INSERT_CARD, HWCRHK_R_NO_CALLBACK);
1265         return -1;
1266     }
1267
1268     ui = UI_new_method(ui_method);
1269
1270     if (ui) {
1271         char answer;
1272         char buf[BUFSIZ];
1273         /*
1274          * Despite what the documentation says wrong_info can be an empty
1275          * string.
1276          */
1277         if (wrong_info && *wrong_info)
1278             BIO_snprintf(buf, sizeof(buf) - 1,
1279                          "Current card: \"%s\"\n", wrong_info);
1280         else
1281             buf[0] = 0;
1282         ok = UI_dup_info_string(ui, buf);
1283         if (ok >= 0 && prompt_info) {
1284             BIO_snprintf(buf, sizeof(buf) - 1,
1285                          "Insert card \"%s\"", prompt_info);
1286             ok = UI_dup_input_boolean(ui, buf,
1287                                       "\n then hit <enter> or C<enter> to cancel\n",
1288                                       "\r\n", "Cc", UI_INPUT_FLAG_ECHO,
1289                                       &answer);
1290         }
1291         UI_add_user_data(ui, callback_data);
1292
1293         if (ok >= 0)
1294             ok = UI_process(ui);
1295         UI_free(ui);
1296
1297         if (ok == -2 || (ok >= 0 && answer == 'C'))
1298             ok = 1;
1299         else if (ok < 0)
1300             ok = -1;
1301         else
1302             ok = 0;
1303     }
1304     return ok;
1305 }
1306
1307 static void hwcrhk_log_message(void *logstr, const char *message)
1308 {
1309     BIO *lstream = NULL;
1310
1311     CRYPTO_w_lock(CRYPTO_LOCK_BIO);
1312     if (logstr)
1313         lstream = *(BIO **)logstr;
1314     if (lstream) {
1315         BIO_printf(lstream, "%s\n", message);
1316     }
1317     CRYPTO_w_unlock(CRYPTO_LOCK_BIO);
1318 }
1319
1320 /*
1321  * This stuff is needed if this ENGINE is being compiled into a
1322  * self-contained shared-library.
1323  */
1324 #  ifndef OPENSSL_NO_DYNAMIC_ENGINE
1325 static int bind_fn(ENGINE *e, const char *id)
1326 {
1327     if (id && (strcmp(id, engine_hwcrhk_id) != 0) &&
1328         (strcmp(id, engine_hwcrhk_id_alt) != 0))
1329         return 0;
1330     if (!bind_helper(e))
1331         return 0;
1332     return 1;
1333 }
1334
1335 IMPLEMENT_DYNAMIC_CHECK_FN()
1336     IMPLEMENT_DYNAMIC_BIND_FN(bind_fn)
1337 #  endif                        /* OPENSSL_NO_DYNAMIC_ENGINE */
1338 # endif                         /* !OPENSSL_NO_HW_CHIL */
1339 #endif                          /* !OPENSSL_NO_HW */