crypto/asn1/bio_asn1.c

   1 /*
   2  * Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*
  11  * Experimental ASN1 BIO. When written through the data is converted to an
  12  * ASN1 string type: default is OCTET STRING. Additional functions can be
  13  * provided to add prefix and suffix data.
  14  */
  15
  16 #include <string.h>
  17 #include "internal/bio.h"
  18 #include <openssl/asn1.h>
  19 #include "internal/cryptlib.h"
  20
  21 /* Must be large enough for biggest tag+length */
  22 #define DEFAULT_ASN1_BUF_SIZE 20
  23
  24 typedef enum {
  25     ASN1_STATE_START,
  26     ASN1_STATE_PRE_COPY,
  27     ASN1_STATE_HEADER,
  28     ASN1_STATE_HEADER_COPY,
  29     ASN1_STATE_DATA_COPY,
  30     ASN1_STATE_POST_COPY,
  31     ASN1_STATE_DONE
  32 } asn1_bio_state_t;
  33
  34 typedef struct BIO_ASN1_EX_FUNCS_st {
  35     asn1_ps_func *ex_func;
  36     asn1_ps_func *ex_free_func;
  37 } BIO_ASN1_EX_FUNCS;
  38
  39 typedef struct BIO_ASN1_BUF_CTX_t {
  40     /* Internal state */
  41     asn1_bio_state_t state;
  42     /* Internal buffer */
  43     unsigned char *buf;
  44     /* Size of buffer */
  45     int bufsize;
  46     /* Current position in buffer */
  47     int bufpos;
  48     /* Current buffer length */
  49     int buflen;
  50     /* Amount of data to copy */
  51     int copylen;
  52     /* Class and tag to use */
  53     int asn1_class, asn1_tag;
  54     asn1_ps_func *prefix, *prefix_free, *suffix, *suffix_free;
  55     /* Extra buffer for prefix and suffix data */
  56     unsigned char *ex_buf;
  57     int ex_len;
  58     int ex_pos;
  59     void *ex_arg;
  60 } BIO_ASN1_BUF_CTX;
  61
  62 static int asn1_bio_write(BIO *h, const char *buf, int num);
  63 static int asn1_bio_read(BIO *h, char *buf, int size);
  64 static int asn1_bio_puts(BIO *h, const char *str);
  65 static int asn1_bio_gets(BIO *h, char *str, int size);
  66 static long asn1_bio_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  67 static int asn1_bio_new(BIO *h);
  68 static int asn1_bio_free(BIO *data);
  69 static long asn1_bio_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
  70
  71 static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size);
  72 static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
  73                              asn1_ps_func *cleanup, asn1_bio_state_t next);
  74 static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
  75                              asn1_ps_func *setup,
  76                              asn1_bio_state_t ex_state,
  77                              asn1_bio_state_t other_state);
  78
  79 static const BIO_METHOD methods_asn1 = {
  80     BIO_TYPE_ASN1,
  81     "asn1",
  82     /* TODO: Convert to new style write function */
  83     bwrite_conv,
  84     asn1_bio_write,
  85     /* TODO: Convert to new style read function */
  86     bread_conv,
  87     asn1_bio_read,
  88     asn1_bio_puts,
  89     asn1_bio_gets,
  90     asn1_bio_ctrl,
  91     asn1_bio_new,
  92     asn1_bio_free,
  93     asn1_bio_callback_ctrl,
  94 };
  95
  96 const BIO_METHOD *BIO_f_asn1(void)
  97 {
  98     return (&methods_asn1);
  99 }
 100
 101 static int asn1_bio_new(BIO *b)
 102 {
 103     BIO_ASN1_BUF_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
 104
 105     if (ctx == NULL)
 106         return 0;
 107     if (!asn1_bio_init(ctx, DEFAULT_ASN1_BUF_SIZE)) {
 108         OPENSSL_free(ctx);
 109         return 0;
 110     }
 111     BIO_set_data(b, ctx);
 112     BIO_set_init(b, 1);
 113
 114     return 1;
 115 }
 116
 117 static int asn1_bio_init(BIO_ASN1_BUF_CTX *ctx, int size)
 118 {
 119     ctx->buf = OPENSSL_malloc(size);
 120     if (ctx->buf == NULL)
 121         return 0;
 122     ctx->bufsize = size;
 123     ctx->asn1_class = V_ASN1_UNIVERSAL;
 124     ctx->asn1_tag = V_ASN1_OCTET_STRING;
 125     ctx->state = ASN1_STATE_START;
 126     return 1;
 127 }
 128
 129 static int asn1_bio_free(BIO *b)
 130 {
 131     BIO_ASN1_BUF_CTX *ctx;
 132
 133     if (b == NULL)
 134         return 0;
 135
 136     ctx = BIO_get_data(b);
 137     if (ctx == NULL)
 138         return 0;
 139
 140     OPENSSL_free(ctx->buf);
 141     OPENSSL_free(ctx);
 142     BIO_set_data(b, NULL);
 143     BIO_set_init(b, 0);
 144
 145     return 1;
 146 }
 147
 148 static int asn1_bio_write(BIO *b, const char *in, int inl)
 149 {
 150     BIO_ASN1_BUF_CTX *ctx;
 151     int wrmax, wrlen, ret;
 152     unsigned char *p;
 153     BIO *next;
 154
 155     ctx = BIO_get_data(b);
 156     next = BIO_next(b);
 157     if (in == NULL || inl < 0 || ctx == NULL || next == NULL)
 158         return 0;
 159
 160     wrlen = 0;
 161     ret = -1;
 162
 163     for (;;) {
 164         switch (ctx->state) {
 165             /* Setup prefix data, call it */
 166         case ASN1_STATE_START:
 167             if (!asn1_bio_setup_ex(b, ctx, ctx->prefix,
 168                                    ASN1_STATE_PRE_COPY, ASN1_STATE_HEADER))
 169                 return 0;
 170             break;
 171
 172             /* Copy any pre data first */
 173         case ASN1_STATE_PRE_COPY:
 174
 175             ret = asn1_bio_flush_ex(b, ctx, ctx->prefix_free,
 176                                     ASN1_STATE_HEADER);
 177
 178             if (ret <= 0)
 179                 goto done;
 180
 181             break;
 182
 183         case ASN1_STATE_HEADER:
 184             ctx->buflen = ASN1_object_size(0, inl, ctx->asn1_tag) - inl;
 185             if (!ossl_assert(ctx->buflen <= ctx->bufsize))
 186                 return 0;
 187             p = ctx->buf;
 188             ASN1_put_object(&p, 0, inl, ctx->asn1_tag, ctx->asn1_class);
 189             ctx->copylen = inl;
 190             ctx->state = ASN1_STATE_HEADER_COPY;
 191
 192             break;
 193
 194         case ASN1_STATE_HEADER_COPY:
 195             ret = BIO_write(next, ctx->buf + ctx->bufpos, ctx->buflen);
 196             if (ret <= 0)
 197                 goto done;
 198
 199             ctx->buflen -= ret;
 200             if (ctx->buflen)
 201                 ctx->bufpos += ret;
 202             else {
 203                 ctx->bufpos = 0;
 204                 ctx->state = ASN1_STATE_DATA_COPY;
 205             }
 206
 207             break;
 208
 209         case ASN1_STATE_DATA_COPY:
 210
 211             if (inl > ctx->copylen)
 212                 wrmax = ctx->copylen;
 213             else
 214                 wrmax = inl;
 215             ret = BIO_write(next, in, wrmax);
 216             if (ret <= 0)
 217                 goto done;
 218             wrlen += ret;
 219             ctx->copylen -= ret;
 220             in += ret;
 221             inl -= ret;
 222
 223             if (ctx->copylen == 0)
 224                 ctx->state = ASN1_STATE_HEADER;
 225
 226             if (inl == 0)
 227                 goto done;
 228
 229             break;
 230
 231         case ASN1_STATE_POST_COPY:
 232         case ASN1_STATE_DONE:
 233             BIO_clear_retry_flags(b);
 234             return 0;
 235
 236         }
 237
 238     }
 239
 240  done:
 241     BIO_clear_retry_flags(b);
 242     BIO_copy_next_retry(b);
 243
 244     return (wrlen > 0) ? wrlen : ret;
 245
 246 }
 247
 248 static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
 249                              asn1_ps_func *cleanup, asn1_bio_state_t next)
 250 {
 251     int ret;
 252
 253     if (ctx->ex_len <= 0)
 254         return 1;
 255     for (;;) {
 256         ret = BIO_write(BIO_next(b), ctx->ex_buf + ctx->ex_pos, ctx->ex_len);
 257         if (ret <= 0)
 258             break;
 259         ctx->ex_len -= ret;
 260         if (ctx->ex_len > 0)
 261             ctx->ex_pos += ret;
 262         else {
 263             if (cleanup)
 264                 cleanup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg);
 265             ctx->state = next;
 266             ctx->ex_pos = 0;
 267             break;
 268         }
 269     }
 270     return ret;
 271 }
 272
 273 static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,
 274                              asn1_ps_func *setup,
 275                              asn1_bio_state_t ex_state,
 276                              asn1_bio_state_t other_state)
 277 {
 278     if (setup && !setup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg)) {
 279         BIO_clear_retry_flags(b);
 280         return 0;
 281     }
 282     if (ctx->ex_len > 0)
 283         ctx->state = ex_state;
 284     else
 285         ctx->state = other_state;
 286     return 1;
 287 }
 288
 289 static int asn1_bio_read(BIO *b, char *in, int inl)
 290 {
 291     BIO *next = BIO_next(b);
 292     if (next == NULL)
 293         return 0;
 294     return BIO_read(next, in, inl);
 295 }
 296
 297 static int asn1_bio_puts(BIO *b, const char *str)
 298 {
 299     return asn1_bio_write(b, str, strlen(str));
 300 }
 301
 302 static int asn1_bio_gets(BIO *b, char *str, int size)
 303 {
 304     BIO *next = BIO_next(b);
 305     if (next == NULL)
 306         return 0;
 307     return BIO_gets(next, str, size);
 308 }
 309
 310 static long asn1_bio_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
 311 {
 312     BIO *next = BIO_next(b);
 313     if (next == NULL)
 314         return 0;
 315     return BIO_callback_ctrl(next, cmd, fp);
 316 }
 317
 318 static long asn1_bio_ctrl(BIO *b, int cmd, long arg1, void *arg2)
 319 {
 320     BIO_ASN1_BUF_CTX *ctx;
 321     BIO_ASN1_EX_FUNCS *ex_func;
 322     long ret = 1;
 323     BIO *next;
 324
 325     ctx = BIO_get_data(b);
 326     if (ctx == NULL)
 327         return 0;
 328     next = BIO_next(b);
 329     switch (cmd) {
 330
 331     case BIO_C_SET_PREFIX:
 332         ex_func = arg2;
 333         ctx->prefix = ex_func->ex_func;
 334         ctx->prefix_free = ex_func->ex_free_func;
 335         break;
 336
 337     case BIO_C_GET_PREFIX:
 338         ex_func = arg2;
 339         ex_func->ex_func = ctx->prefix;
 340         ex_func->ex_free_func = ctx->prefix_free;
 341         break;
 342
 343     case BIO_C_SET_SUFFIX:
 344         ex_func = arg2;
 345         ctx->suffix = ex_func->ex_func;
 346         ctx->suffix_free = ex_func->ex_free_func;
 347         break;
 348
 349     case BIO_C_GET_SUFFIX:
 350         ex_func = arg2;
 351         ex_func->ex_func = ctx->suffix;
 352         ex_func->ex_free_func = ctx->suffix_free;
 353         break;
 354
 355     case BIO_C_SET_EX_ARG:
 356         ctx->ex_arg = arg2;
 357         break;
 358
 359     case BIO_C_GET_EX_ARG:
 360         *(void **)arg2 = ctx->ex_arg;
 361         break;
 362
 363     case BIO_CTRL_FLUSH:
 364         if (next == NULL)
 365             return 0;
 366
 367         /* Call post function if possible */
 368         if (ctx->state == ASN1_STATE_HEADER) {
 369             if (!asn1_bio_setup_ex(b, ctx, ctx->suffix,
 370                                    ASN1_STATE_POST_COPY, ASN1_STATE_DONE))
 371                 return 0;
 372         }
 373
 374         if (ctx->state == ASN1_STATE_POST_COPY) {
 375             ret = asn1_bio_flush_ex(b, ctx, ctx->suffix_free,
 376                                     ASN1_STATE_DONE);
 377             if (ret <= 0)
 378                 return ret;
 379         }
 380
 381         if (ctx->state == ASN1_STATE_DONE)
 382             return BIO_ctrl(next, cmd, arg1, arg2);
 383         else {
 384             BIO_clear_retry_flags(b);
 385             return 0;
 386         }
 387
 388     default:
 389         if (next == NULL)
 390             return 0;
 391         return BIO_ctrl(next, cmd, arg1, arg2);
 392
 393     }
 394
 395     return ret;
 396 }
 397
 398 static int asn1_bio_set_ex(BIO *b, int cmd,
 399                            asn1_ps_func *ex_func, asn1_ps_func *ex_free_func)
 400 {
 401     BIO_ASN1_EX_FUNCS extmp;
 402     extmp.ex_func = ex_func;
 403     extmp.ex_free_func = ex_free_func;
 404     return BIO_ctrl(b, cmd, 0, &extmp);
 405 }
 406
 407 static int asn1_bio_get_ex(BIO *b, int cmd,
 408                            asn1_ps_func **ex_func,
 409                            asn1_ps_func **ex_free_func)
 410 {
 411     BIO_ASN1_EX_FUNCS extmp;
 412     int ret;
 413     ret = BIO_ctrl(b, cmd, 0, &extmp);
 414     if (ret > 0) {
 415         *ex_func = extmp.ex_func;
 416         *ex_free_func = extmp.ex_free_func;
 417     }
 418     return ret;
 419 }
 420
 421 int BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix,
 422                         asn1_ps_func *prefix_free)
 423 {
 424     return asn1_bio_set_ex(b, BIO_C_SET_PREFIX, prefix, prefix_free);
 425 }
 426
 427 int BIO_asn1_get_prefix(BIO *b, asn1_ps_func **pprefix,
 428                         asn1_ps_func **pprefix_free)
 429 {
 430     return asn1_bio_get_ex(b, BIO_C_GET_PREFIX, pprefix, pprefix_free);
 431 }
 432
 433 int BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix,
 434                         asn1_ps_func *suffix_free)
 435 {
 436     return asn1_bio_set_ex(b, BIO_C_SET_SUFFIX, suffix, suffix_free);
 437 }
 438
 439 int BIO_asn1_get_suffix(BIO *b, asn1_ps_func **psuffix,
 440                         asn1_ps_func **psuffix_free)
 441 {
 442     return asn1_bio_get_ex(b, BIO_C_GET_SUFFIX, psuffix, psuffix_free);
 443 }