crypto/asn1/asn1_parse.c

   1 /*
   2  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/buffer.h>
  13 #include <openssl/objects.h>
  14 #include <openssl/asn1.h>
  15
  16 #ifndef ASN1_PARSE_MAXDEPTH
  17 #define ASN1_PARSE_MAXDEPTH 128
  18 #endif
  19
  20 static int asn1_parse2(BIO *bp, const unsigned char **pp, long length,
  21                        int offset, int depth, int indent, int dump);
  22 static int asn1_print_info(BIO *bp, long offset, int depth, int hl, long len,
  23                            int tag, int xclass, int constructed, int indent)
  24 {
  25     char str[128];
  26     const char *p;
  27     int pop_f_prefix = 0;
  28     long saved_indent = -1;
  29     int i = 0;
  30
  31     if (constructed & V_ASN1_CONSTRUCTED)
  32         p = "cons: ";
  33     else
  34         p = "prim: ";
  35     if (constructed != (V_ASN1_CONSTRUCTED | 1)) {
  36         if (BIO_snprintf(str, sizeof(str), "%5ld:d=%-2d hl=%ld l=%4ld %s",
  37                          offset, depth, (long)hl, len, p) <= 0)
  38             goto err;
  39     } else {
  40         if (BIO_snprintf(str, sizeof(str), "%5ld:d=%-2d hl=%ld l=inf  %s",
  41                          offset, depth, (long)hl, p) <= 0)
  42             goto err;
  43     }
  44     if (BIO_set_prefix(bp, str) <= 0) {
  45         if ((bp = BIO_push(BIO_new(BIO_f_prefix()), bp)) == NULL)
  46             goto err;
  47         pop_f_prefix = 1;
  48     }
  49     saved_indent = BIO_get_indent(bp);
  50     if (BIO_set_prefix(bp, str) <= 0
  51         || BIO_set_indent(bp, indent) < 0)
  52         goto err;
  53
  54     /*
  55      * BIO_set_prefix made a copy of |str|, so we can safely use it for
  56      * something else, ASN.1 tag printout.
  57      */
  58     p = str;
  59     if ((xclass & V_ASN1_PRIVATE) == V_ASN1_PRIVATE)
  60         BIO_snprintf(str, sizeof(str), "priv [ %d ] ", tag);
  61     else if ((xclass & V_ASN1_CONTEXT_SPECIFIC) == V_ASN1_CONTEXT_SPECIFIC)
  62         BIO_snprintf(str, sizeof(str), "cont [ %d ]", tag);
  63     else if ((xclass & V_ASN1_APPLICATION) == V_ASN1_APPLICATION)
  64         BIO_snprintf(str, sizeof(str), "appl [ %d ]", tag);
  65     else if (tag > 30)
  66         BIO_snprintf(str, sizeof(str), "<ASN1 %d>", tag);
  67     else
  68         p = ASN1_tag2str(tag);
  69
  70     i = (BIO_printf(bp, "%-18s", p) > 0);
  71  err:
  72     if (saved_indent >= 0)
  73         BIO_set_indent(bp, saved_indent);
  74     if (pop_f_prefix) {
  75         BIO_pop(bp);
  76         BIO_free(bp);
  77     }
  78     return i;
  79 }
  80
  81 int ASN1_parse(BIO *bp, const unsigned char *pp, long len, int indent)
  82 {
  83     return asn1_parse2(bp, &pp, len, 0, 0, indent, 0);
  84 }
  85
  86 int ASN1_parse_dump(BIO *bp, const unsigned char *pp, long len, int indent,
  87                     int dump)
  88 {
  89     return asn1_parse2(bp, &pp, len, 0, 0, indent, dump);
  90 }
  91
  92 static int asn1_parse2(BIO *bp, const unsigned char **pp, long length,
  93                        int offset, int depth, int indent, int dump)
  94 {
  95     const unsigned char *p, *ep, *tot, *op, *opp;
  96     long len;
  97     int tag, xclass, ret = 0;
  98     int nl, hl, j, r;
  99     ASN1_OBJECT *o = NULL;
 100     ASN1_OCTET_STRING *os = NULL;
 101     ASN1_INTEGER *ai = NULL;
 102     ASN1_ENUMERATED *ae = NULL;
 103     /* ASN1_BMPSTRING *bmp=NULL; */
 104     int dump_indent, dump_cont = 0;
 105
 106     if (depth > ASN1_PARSE_MAXDEPTH) {
 107         BIO_puts(bp, "BAD RECURSION DEPTH\n");
 108         return 0;
 109     }
 110
 111     dump_indent = 6;            /* Because we know BIO_dump_indent() */
 112     p = *pp;
 113     tot = p + length;
 114     while (length > 0) {
 115         op = p;
 116         j = ASN1_get_object(&p, &len, &tag, &xclass, length);
 117         if (j & 0x80) {
 118             BIO_puts(bp, "Error in encoding\n");
 119             goto end;
 120         }
 121         hl = (p - op);
 122         length -= hl;
 123         /*
 124          * if j == 0x21 it is a constructed indefinite length object
 125          */
 126         if (!asn1_print_info(bp, (long)offset + (long)(op - *pp), depth,
 127                              hl, len, tag, xclass, j, (indent) ? depth : 0))
 128             goto end;
 129         if (j & V_ASN1_CONSTRUCTED) {
 130             const unsigned char *sp = p;
 131
 132             ep = p + len;
 133             if (BIO_write(bp, "\n", 1) <= 0)
 134                 goto end;
 135             if (len > length) {
 136                 BIO_printf(bp, "length is greater than %ld\n", length);
 137                 goto end;
 138             }
 139             if ((j == 0x21) && (len == 0)) {
 140                 for (;;) {
 141                     r = asn1_parse2(bp, &p, (long)(tot - p),
 142                                     offset + (p - *pp), depth + 1,
 143                                     indent, dump);
 144                     if (r == 0)
 145                         goto end;
 146                     if ((r == 2) || (p >= tot)) {
 147                         len = p - sp;
 148                         break;
 149                     }
 150                 }
 151             } else {
 152                 long tmp = len;
 153
 154                 while (p < ep) {
 155                     sp = p;
 156                     r = asn1_parse2(bp, &p, tmp,
 157                                     offset + (p - *pp), depth + 1,
 158                                     indent, dump);
 159                     if (r == 0)
 160                         goto end;
 161                     tmp -= p - sp;
 162                 }
 163             }
 164         } else if (xclass != 0) {
 165             p += len;
 166             if (BIO_write(bp, "\n", 1) <= 0)
 167                 goto end;
 168         } else {
 169             nl = 0;
 170             if ((tag == V_ASN1_PRINTABLESTRING) ||
 171                 (tag == V_ASN1_T61STRING) ||
 172                 (tag == V_ASN1_IA5STRING) ||
 173                 (tag == V_ASN1_VISIBLESTRING) ||
 174                 (tag == V_ASN1_NUMERICSTRING) ||
 175                 (tag == V_ASN1_UTF8STRING) ||
 176                 (tag == V_ASN1_UTCTIME) || (tag == V_ASN1_GENERALIZEDTIME)) {
 177                 if (BIO_write(bp, ":", 1) <= 0)
 178                     goto end;
 179                 if ((len > 0) && BIO_write(bp, (const char *)p, (int)len)
 180                     != (int)len)
 181                     goto end;
 182             } else if (tag == V_ASN1_OBJECT) {
 183                 opp = op;
 184                 if (d2i_ASN1_OBJECT(&o, &opp, len + hl) != NULL) {
 185                     if (BIO_write(bp, ":", 1) <= 0)
 186                         goto end;
 187                     i2a_ASN1_OBJECT(bp, o);
 188                 } else {
 189                     if (BIO_puts(bp, ":BAD OBJECT") <= 0)
 190                         goto end;
 191                     dump_cont = 1;
 192                 }
 193             } else if (tag == V_ASN1_BOOLEAN) {
 194                 if (len != 1) {
 195                     if (BIO_puts(bp, ":BAD BOOLEAN") <= 0)
 196                         goto end;
 197                     dump_cont = 1;
 198                 }
 199                 if (len > 0)
 200                     BIO_printf(bp, ":%u", p[0]);
 201             } else if (tag == V_ASN1_BMPSTRING) {
 202                 /* do the BMP thang */
 203             } else if (tag == V_ASN1_OCTET_STRING) {
 204                 int i, printable = 1;
 205
 206                 opp = op;
 207                 os = d2i_ASN1_OCTET_STRING(NULL, &opp, len + hl);
 208                 if (os != NULL && os->length > 0) {
 209                     opp = os->data;
 210                     /*
 211                      * testing whether the octet string is printable
 212                      */
 213                     for (i = 0; i < os->length; i++) {
 214                         if (((opp[i] < ' ') &&
 215                              (opp[i] != '\n') &&
 216                              (opp[i] != '\r') &&
 217                              (opp[i] != '\t')) || (opp[i] > '~')) {
 218                             printable = 0;
 219                             break;
 220                         }
 221                     }
 222                     if (printable)
 223                         /* printable string */
 224                     {
 225                         if (BIO_write(bp, ":", 1) <= 0)
 226                             goto end;
 227                         if (BIO_write(bp, (const char *)opp, os->length) <= 0)
 228                             goto end;
 229                     } else if (!dump)
 230                         /*
 231                          * not printable => print octet string as hex dump
 232                          */
 233                     {
 234                         if (BIO_write(bp, "[HEX DUMP]:", 11) <= 0)
 235                             goto end;
 236                         for (i = 0; i < os->length; i++) {
 237                             if (BIO_printf(bp, "%02X", opp[i]) <= 0)
 238                                 goto end;
 239                         }
 240                     } else
 241                         /* print the normal dump */
 242                     {
 243                         if (!nl) {
 244                             if (BIO_write(bp, "\n", 1) <= 0)
 245                                 goto end;
 246                         }
 247                         if (BIO_dump_indent(bp,
 248                                             (const char *)opp,
 249                                             ((dump == -1 || dump >
 250                                               os->
 251                                               length) ? os->length : dump),
 252                                             dump_indent) <= 0)
 253                             goto end;
 254                         nl = 1;
 255                     }
 256                 }
 257                 ASN1_OCTET_STRING_free(os);
 258                 os = NULL;
 259             } else if (tag == V_ASN1_INTEGER) {
 260                 int i;
 261
 262                 opp = op;
 263                 ai = d2i_ASN1_INTEGER(NULL, &opp, len + hl);
 264                 if (ai != NULL) {
 265                     if (BIO_write(bp, ":", 1) <= 0)
 266                         goto end;
 267                     if (ai->type == V_ASN1_NEG_INTEGER)
 268                         if (BIO_write(bp, "-", 1) <= 0)
 269                             goto end;
 270                     for (i = 0; i < ai->length; i++) {
 271                         if (BIO_printf(bp, "%02X", ai->data[i]) <= 0)
 272                             goto end;
 273                     }
 274                     if (ai->length == 0) {
 275                         if (BIO_write(bp, "00", 2) <= 0)
 276                             goto end;
 277                     }
 278                 } else {
 279                     if (BIO_puts(bp, ":BAD INTEGER") <= 0)
 280                         goto end;
 281                     dump_cont = 1;
 282                 }
 283                 ASN1_INTEGER_free(ai);
 284                 ai = NULL;
 285             } else if (tag == V_ASN1_ENUMERATED) {
 286                 int i;
 287
 288                 opp = op;
 289                 ae = d2i_ASN1_ENUMERATED(NULL, &opp, len + hl);
 290                 if (ae != NULL) {
 291                     if (BIO_write(bp, ":", 1) <= 0)
 292                         goto end;
 293                     if (ae->type == V_ASN1_NEG_ENUMERATED)
 294                         if (BIO_write(bp, "-", 1) <= 0)
 295                             goto end;
 296                     for (i = 0; i < ae->length; i++) {
 297                         if (BIO_printf(bp, "%02X", ae->data[i]) <= 0)
 298                             goto end;
 299                     }
 300                     if (ae->length == 0) {
 301                         if (BIO_write(bp, "00", 2) <= 0)
 302                             goto end;
 303                     }
 304                 } else {
 305                     if (BIO_puts(bp, ":BAD ENUMERATED") <= 0)
 306                         goto end;
 307                     dump_cont = 1;
 308                 }
 309                 ASN1_ENUMERATED_free(ae);
 310                 ae = NULL;
 311             } else if (len > 0 && dump) {
 312                 if (!nl) {
 313                     if (BIO_write(bp, "\n", 1) <= 0)
 314                         goto end;
 315                 }
 316                 if (BIO_dump_indent(bp, (const char *)p,
 317                                     ((dump == -1 || dump > len) ? len : dump),
 318                                     dump_indent) <= 0)
 319                     goto end;
 320                 nl = 1;
 321             }
 322             if (dump_cont) {
 323                 int i;
 324                 const unsigned char *tmp = op + hl;
 325                 if (BIO_puts(bp, ":[") <= 0)
 326                     goto end;
 327                 for (i = 0; i < len; i++) {
 328                     if (BIO_printf(bp, "%02X", tmp[i]) <= 0)
 329                         goto end;
 330                 }
 331                 if (BIO_puts(bp, "]") <= 0)
 332                     goto end;
 333                 dump_cont = 0;
 334             }
 335
 336             if (!nl) {
 337                 if (BIO_write(bp, "\n", 1) <= 0)
 338                     goto end;
 339             }
 340             p += len;
 341             if ((tag == V_ASN1_EOC) && (xclass == 0)) {
 342                 ret = 2;        /* End of sequence */
 343                 goto end;
 344             }
 345         }
 346         length -= len;
 347     }
 348     ret = 1;
 349  end:
 350     ASN1_OBJECT_free(o);
 351     ASN1_OCTET_STRING_free(os);
 352     ASN1_INTEGER_free(ai);
 353     ASN1_ENUMERATED_free(ae);
 354     *pp = p;
 355     return ret;
 356 }
 357
 358 const char *ASN1_tag2str(int tag)
 359 {
 360     static const char *const tag2str[] = {
 361         /* 0-4 */
 362         "EOC", "BOOLEAN", "INTEGER", "BIT STRING", "OCTET STRING",
 363         /* 5-9 */
 364         "NULL", "OBJECT", "OBJECT DESCRIPTOR", "EXTERNAL", "REAL",
 365         /* 10-13 */
 366         "ENUMERATED", "<ASN1 11>", "UTF8STRING", "<ASN1 13>",
 367         /* 15-17 */
 368         "<ASN1 14>", "<ASN1 15>", "SEQUENCE", "SET",
 369         /* 18-20 */
 370         "NUMERICSTRING", "PRINTABLESTRING", "T61STRING",
 371         /* 21-24 */
 372         "VIDEOTEXSTRING", "IA5STRING", "UTCTIME", "GENERALIZEDTIME",
 373         /* 25-27 */
 374         "GRAPHICSTRING", "VISIBLESTRING", "GENERALSTRING",
 375         /* 28-30 */
 376         "UNIVERSALSTRING", "<ASN1 29>", "BMPSTRING"
 377     };
 378
 379     if ((tag == V_ASN1_NEG_INTEGER) || (tag == V_ASN1_NEG_ENUMERATED))
 380         tag &= ~0x100;
 381
 382     if (tag < 0 || tag > 30)
 383         return "(unknown)";
 384     return tag2str[tag];
 385 }