crypto/asn1/a_strex.c

   1 /*
   2  * Copyright 2000-2020 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 <string.h>
  12 #include "internal/cryptlib.h"
  13 #include "crypto/asn1.h"
  14 #include <openssl/crypto.h>
  15 #include <openssl/x509.h>
  16 #include <openssl/asn1.h>
  17
  18 #include "charmap.h"
  19
  20 /*
  21  * ASN1_STRING_print_ex() and X509_NAME_print_ex(). Enhanced string and name
  22  * printing routines handling multibyte characters, RFC2253 and a host of
  23  * other options.
  24  */
  25
  26 #define CHARTYPE_BS_ESC         (ASN1_STRFLGS_ESC_2253 | CHARTYPE_FIRST_ESC_2253 | CHARTYPE_LAST_ESC_2253)
  27
  28 #define ESC_FLAGS (ASN1_STRFLGS_ESC_2253 | \
  29                   ASN1_STRFLGS_ESC_2254 | \
  30                   ASN1_STRFLGS_ESC_QUOTE | \
  31                   ASN1_STRFLGS_ESC_CTRL | \
  32                   ASN1_STRFLGS_ESC_MSB)
  33
  34 /*
  35  * Three IO functions for sending data to memory, a BIO and a FILE
  36  * pointer.
  37  */
  38 static int send_bio_chars(void *arg, const void *buf, int len)
  39 {
  40     if (!arg)
  41         return 1;
  42     if (BIO_write(arg, buf, len) != len)
  43         return 0;
  44     return 1;
  45 }
  46
  47 #ifndef OPENSSL_NO_STDIO
  48 static int send_fp_chars(void *arg, const void *buf, int len)
  49 {
  50     if (!arg)
  51         return 1;
  52     if (fwrite(buf, 1, len, arg) != (unsigned int)len)
  53         return 0;
  54     return 1;
  55 }
  56 #endif
  57
  58 typedef int char_io (void *arg, const void *buf, int len);
  59
  60 /*
  61  * This function handles display of strings, one character at a time. It is
  62  * passed an unsigned long for each character because it could come from 2 or
  63  * even 4 byte forms.
  64  */
  65
  66 static int do_esc_char(unsigned long c, unsigned short flags, char *do_quotes,
  67                        char_io *io_ch, void *arg)
  68 {
  69     unsigned short chflgs;
  70     unsigned char chtmp;
  71     char tmphex[HEX_SIZE(long) + 3];
  72
  73     if (c > 0xffffffffL)
  74         return -1;
  75     if (c > 0xffff) {
  76         BIO_snprintf(tmphex, sizeof(tmphex), "\\W%08lX", c);
  77         if (!io_ch(arg, tmphex, 10))
  78             return -1;
  79         return 10;
  80     }
  81     if (c > 0xff) {
  82         BIO_snprintf(tmphex, sizeof(tmphex), "\\U%04lX", c);
  83         if (!io_ch(arg, tmphex, 6))
  84             return -1;
  85         return 6;
  86     }
  87     chtmp = (unsigned char)c;
  88     if (chtmp > 0x7f)
  89         chflgs = flags & ASN1_STRFLGS_ESC_MSB;
  90     else
  91         chflgs = char_type[chtmp] & flags;
  92     if (chflgs & CHARTYPE_BS_ESC) {
  93         /* If we don't escape with quotes, signal we need quotes */
  94         if (chflgs & ASN1_STRFLGS_ESC_QUOTE) {
  95             if (do_quotes)
  96                 *do_quotes = 1;
  97             if (!io_ch(arg, &chtmp, 1))
  98                 return -1;
  99             return 1;
 100         }
 101         if (!io_ch(arg, "\\", 1))
 102             return -1;
 103         if (!io_ch(arg, &chtmp, 1))
 104             return -1;
 105         return 2;
 106     }
 107     if (chflgs & (ASN1_STRFLGS_ESC_CTRL
 108                   | ASN1_STRFLGS_ESC_MSB
 109                   | ASN1_STRFLGS_ESC_2254)) {
 110         BIO_snprintf(tmphex, 11, "\\%02X", chtmp);
 111         if (!io_ch(arg, tmphex, 3))
 112             return -1;
 113         return 3;
 114     }
 115     /*
 116      * If we get this far and do any escaping at all must escape the escape
 117      * character itself: backslash.
 118      */
 119     if (chtmp == '\\' && (flags & ESC_FLAGS)) {
 120         if (!io_ch(arg, "\\\\", 2))
 121             return -1;
 122         return 2;
 123     }
 124     if (!io_ch(arg, &chtmp, 1))
 125         return -1;
 126     return 1;
 127 }
 128
 129 #define BUF_TYPE_WIDTH_MASK     0x7
 130 #define BUF_TYPE_CONVUTF8       0x8
 131
 132 /*
 133  * This function sends each character in a buffer to do_esc_char(). It
 134  * interprets the content formats and converts to or from UTF8 as
 135  * appropriate.
 136  */
 137
 138 static int do_buf(unsigned char *buf, int buflen,
 139                   int type, unsigned short flags, char *quotes, char_io *io_ch,
 140                   void *arg)
 141 {
 142     int i, outlen, len, charwidth;
 143     unsigned short orflags;
 144     unsigned char *p, *q;
 145     unsigned long c;
 146
 147     p = buf;
 148     q = buf + buflen;
 149     outlen = 0;
 150     charwidth = type & BUF_TYPE_WIDTH_MASK;
 151
 152     switch (charwidth) {
 153     case 4:
 154         if (buflen & 3) {
 155             ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_UNIVERSALSTRING_LENGTH);
 156             return -1;
 157         }
 158         break;
 159     case 2:
 160         if (buflen & 1) {
 161             ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_BMPSTRING_LENGTH);
 162             return -1;
 163         }
 164         break;
 165     default:
 166         break;
 167     }
 168
 169     while (p != q) {
 170         if (p == buf && flags & ASN1_STRFLGS_ESC_2253)
 171             orflags = CHARTYPE_FIRST_ESC_2253;
 172         else
 173             orflags = 0;
 174
 175         switch (charwidth) {
 176         case 4:
 177             c = ((unsigned long)*p++) << 24;
 178             c |= ((unsigned long)*p++) << 16;
 179             c |= ((unsigned long)*p++) << 8;
 180             c |= *p++;
 181             break;
 182
 183         case 2:
 184             c = ((unsigned long)*p++) << 8;
 185             c |= *p++;
 186             break;
 187
 188         case 1:
 189             c = *p++;
 190             break;
 191
 192         case 0:
 193             i = UTF8_getc(p, buflen, &c);
 194             if (i < 0)
 195                 return -1;      /* Invalid UTF8String */
 196             buflen -= i;
 197             p += i;
 198             break;
 199         default:
 200             return -1;          /* invalid width */
 201         }
 202         if (p == q && flags & ASN1_STRFLGS_ESC_2253)
 203             orflags = CHARTYPE_LAST_ESC_2253;
 204         if (type & BUF_TYPE_CONVUTF8) {
 205             unsigned char utfbuf[6];
 206             int utflen;
 207             utflen = UTF8_putc(utfbuf, sizeof(utfbuf), c);
 208             for (i = 0; i < utflen; i++) {
 209                 /*
 210                  * We don't need to worry about setting orflags correctly
 211                  * because if utflen==1 its value will be correct anyway
 212                  * otherwise each character will be > 0x7f and so the
 213                  * character will never be escaped on first and last.
 214                  */
 215                 len = do_esc_char(utfbuf[i], flags | orflags, quotes,
 216                                   io_ch, arg);
 217                 if (len < 0)
 218                     return -1;
 219                 outlen += len;
 220             }
 221         } else {
 222             len = do_esc_char(c, flags | orflags, quotes,
 223                               io_ch, arg);
 224             if (len < 0)
 225                 return -1;
 226             outlen += len;
 227         }
 228     }
 229     return outlen;
 230 }
 231
 232 /* This function hex dumps a buffer of characters */
 233
 234 static int do_hex_dump(char_io *io_ch, void *arg, unsigned char *buf,
 235                        int buflen)
 236 {
 237     static const char hexdig[] = "0123456789ABCDEF";
 238     unsigned char *p, *q;
 239     char hextmp[2];
 240     if (arg) {
 241         p = buf;
 242         q = buf + buflen;
 243         while (p != q) {
 244             hextmp[0] = hexdig[*p >> 4];
 245             hextmp[1] = hexdig[*p & 0xf];
 246             if (!io_ch(arg, hextmp, 2))
 247                 return -1;
 248             p++;
 249         }
 250     }
 251     return buflen << 1;
 252 }
 253
 254 /*
 255  * "dump" a string. This is done when the type is unknown, or the flags
 256  * request it. We can either dump the content octets or the entire DER
 257  * encoding. This uses the RFC2253 #01234 format.
 258  */
 259
 260 static int do_dump(unsigned long lflags, char_io *io_ch, void *arg,
 261                    const ASN1_STRING *str)
 262 {
 263     /*
 264      * Placing the ASN1_STRING in a temp ASN1_TYPE allows the DER encoding to
 265      * readily obtained
 266      */
 267     ASN1_TYPE t;
 268     unsigned char *der_buf, *p;
 269     int outlen, der_len;
 270
 271     if (!io_ch(arg, "#", 1))
 272         return -1;
 273     /* If we don't dump DER encoding just dump content octets */
 274     if (!(lflags & ASN1_STRFLGS_DUMP_DER)) {
 275         outlen = do_hex_dump(io_ch, arg, str->data, str->length);
 276         if (outlen < 0)
 277             return -1;
 278         return outlen + 1;
 279     }
 280     t.type = str->type;
 281     t.value.ptr = (char *)str;
 282     der_len = i2d_ASN1_TYPE(&t, NULL);
 283     if ((der_buf = OPENSSL_malloc(der_len)) == NULL) {
 284         ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
 285         return -1;
 286     }
 287     p = der_buf;
 288     i2d_ASN1_TYPE(&t, &p);
 289     outlen = do_hex_dump(io_ch, arg, der_buf, der_len);
 290     OPENSSL_free(der_buf);
 291     if (outlen < 0)
 292         return -1;
 293     return outlen + 1;
 294 }
 295
 296 /*
 297  * Lookup table to convert tags to character widths, 0 = UTF8 encoded, -1 is
 298  * used for non string types otherwise it is the number of bytes per
 299  * character
 300  */
 301
 302 static const signed char tag2nbyte[] = {
 303     -1, -1, -1, -1, -1,         /* 0-4 */
 304     -1, -1, -1, -1, -1,         /* 5-9 */
 305     -1, -1,                     /* 10-11 */
 306      0,                         /* 12 V_ASN1_UTF8STRING */
 307     -1, -1, -1, -1, -1,         /* 13-17 */
 308      1,                         /* 18 V_ASN1_NUMERICSTRING */
 309      1,                         /* 19 V_ASN1_PRINTABLESTRING */
 310      1,                         /* 20 V_ASN1_T61STRING */
 311     -1,                         /* 21 */
 312      1,                         /* 22 V_ASN1_IA5STRING */
 313      1,                         /* 23 V_ASN1_UTCTIME */
 314      1,                         /* 24 V_ASN1_GENERALIZEDTIME */
 315     -1,                         /* 25 */
 316      1,                         /* 26 V_ASN1_ISO64STRING */
 317     -1,                         /* 27 */
 318      4,                         /* 28 V_ASN1_UNIVERSALSTRING */
 319     -1,                         /* 29 */
 320      2                          /* 30 V_ASN1_BMPSTRING */
 321 };
 322
 323 /*
 324  * This is the main function, print out an ASN1_STRING taking note of various
 325  * escape and display options. Returns number of characters written or -1 if
 326  * an error occurred.
 327  */
 328
 329 static int do_print_ex(char_io *io_ch, void *arg, unsigned long lflags,
 330                        const ASN1_STRING *str)
 331 {
 332     int outlen, len;
 333     int type;
 334     char quotes;
 335     unsigned short flags;
 336     quotes = 0;
 337     /* Keep a copy of escape flags */
 338     flags = (unsigned short)(lflags & ESC_FLAGS);
 339
 340     type = str->type;
 341
 342     outlen = 0;
 343
 344     if (lflags & ASN1_STRFLGS_SHOW_TYPE) {
 345         const char *tagname;
 346         tagname = ASN1_tag2str(type);
 347         outlen += strlen(tagname);
 348         if (!io_ch(arg, tagname, outlen) || !io_ch(arg, ":", 1))
 349             return -1;
 350         outlen++;
 351     }
 352
 353     /* Decide what to do with type, either dump content or display it */
 354
 355     /* Dump everything */
 356     if (lflags & ASN1_STRFLGS_DUMP_ALL)
 357         type = -1;
 358     /* Ignore the string type */
 359     else if (lflags & ASN1_STRFLGS_IGNORE_TYPE)
 360         type = 1;
 361     else {
 362         /* Else determine width based on type */
 363         if ((type > 0) && (type < 31))
 364             type = tag2nbyte[type];
 365         else
 366             type = -1;
 367         if ((type == -1) && !(lflags & ASN1_STRFLGS_DUMP_UNKNOWN))
 368             type = 1;
 369     }
 370
 371     if (type == -1) {
 372         len = do_dump(lflags, io_ch, arg, str);
 373         if (len < 0)
 374             return -1;
 375         outlen += len;
 376         return outlen;
 377     }
 378
 379     if (lflags & ASN1_STRFLGS_UTF8_CONVERT) {
 380         /*
 381          * Note: if string is UTF8 and we want to convert to UTF8 then we
 382          * just interpret it as 1 byte per character to avoid converting
 383          * twice.
 384          */
 385         if (!type)
 386             type = 1;
 387         else
 388             type |= BUF_TYPE_CONVUTF8;
 389     }
 390
 391     len = do_buf(str->data, str->length, type, flags, &quotes, io_ch, NULL);
 392     if (len < 0)
 393         return -1;
 394     outlen += len;
 395     if (quotes)
 396         outlen += 2;
 397     if (!arg)
 398         return outlen;
 399     if (quotes && !io_ch(arg, "\"", 1))
 400         return -1;
 401     if (do_buf(str->data, str->length, type, flags, NULL, io_ch, arg) < 0)
 402         return -1;
 403     if (quotes && !io_ch(arg, "\"", 1))
 404         return -1;
 405     return outlen;
 406 }
 407
 408 /* Used for line indenting: print 'indent' spaces */
 409
 410 static int do_indent(char_io *io_ch, void *arg, int indent)
 411 {
 412     int i;
 413     for (i = 0; i < indent; i++)
 414         if (!io_ch(arg, " ", 1))
 415             return 0;
 416     return 1;
 417 }
 418
 419 #define FN_WIDTH_LN     25
 420 #define FN_WIDTH_SN     10
 421
 422 static int do_name_ex(char_io *io_ch, void *arg, const X509_NAME *n,
 423                       int indent, unsigned long flags)
 424 {
 425     int i, prev = -1, orflags, cnt;
 426     int fn_opt, fn_nid;
 427     ASN1_OBJECT *fn;
 428     const ASN1_STRING *val;
 429     const X509_NAME_ENTRY *ent;
 430     char objtmp[80];
 431     const char *objbuf;
 432     int outlen, len;
 433     char *sep_dn, *sep_mv, *sep_eq;
 434     int sep_dn_len, sep_mv_len, sep_eq_len;
 435     if (indent < 0)
 436         indent = 0;
 437     outlen = indent;
 438     if (!do_indent(io_ch, arg, indent))
 439         return -1;
 440     switch (flags & XN_FLAG_SEP_MASK) {
 441     case XN_FLAG_SEP_MULTILINE:
 442         sep_dn = "\n";
 443         sep_dn_len = 1;
 444         sep_mv = " + ";
 445         sep_mv_len = 3;
 446         break;
 447
 448     case XN_FLAG_SEP_COMMA_PLUS:
 449         sep_dn = ",";
 450         sep_dn_len = 1;
 451         sep_mv = "+";
 452         sep_mv_len = 1;
 453         indent = 0;
 454         break;
 455
 456     case XN_FLAG_SEP_CPLUS_SPC:
 457         sep_dn = ", ";
 458         sep_dn_len = 2;
 459         sep_mv = " + ";
 460         sep_mv_len = 3;
 461         indent = 0;
 462         break;
 463
 464     case XN_FLAG_SEP_SPLUS_SPC:
 465         sep_dn = "; ";
 466         sep_dn_len = 2;
 467         sep_mv = " + ";
 468         sep_mv_len = 3;
 469         indent = 0;
 470         break;
 471
 472     default:
 473         return -1;
 474     }
 475
 476     if (flags & XN_FLAG_SPC_EQ) {
 477         sep_eq = " = ";
 478         sep_eq_len = 3;
 479     } else {
 480         sep_eq = "=";
 481         sep_eq_len = 1;
 482     }
 483
 484     fn_opt = flags & XN_FLAG_FN_MASK;
 485
 486     cnt = X509_NAME_entry_count(n);
 487     for (i = 0; i < cnt; i++) {
 488         if (flags & XN_FLAG_DN_REV)
 489             ent = X509_NAME_get_entry(n, cnt - i - 1);
 490         else
 491             ent = X509_NAME_get_entry(n, i);
 492         if (prev != -1) {
 493             if (prev == X509_NAME_ENTRY_set(ent)) {
 494                 if (!io_ch(arg, sep_mv, sep_mv_len))
 495                     return -1;
 496                 outlen += sep_mv_len;
 497             } else {
 498                 if (!io_ch(arg, sep_dn, sep_dn_len))
 499                     return -1;
 500                 outlen += sep_dn_len;
 501                 if (!do_indent(io_ch, arg, indent))
 502                     return -1;
 503                 outlen += indent;
 504             }
 505         }
 506         prev = X509_NAME_ENTRY_set(ent);
 507         fn = X509_NAME_ENTRY_get_object(ent);
 508         val = X509_NAME_ENTRY_get_data(ent);
 509         fn_nid = OBJ_obj2nid(fn);
 510         if (fn_opt != XN_FLAG_FN_NONE) {
 511             int objlen, fld_len;
 512             if ((fn_opt == XN_FLAG_FN_OID) || (fn_nid == NID_undef)) {
 513                 OBJ_obj2txt(objtmp, sizeof(objtmp), fn, 1);
 514                 fld_len = 0;    /* XXX: what should this be? */
 515                 objbuf = objtmp;
 516             } else {
 517                 if (fn_opt == XN_FLAG_FN_SN) {
 518                     fld_len = FN_WIDTH_SN;
 519                     objbuf = OBJ_nid2sn(fn_nid);
 520                 } else if (fn_opt == XN_FLAG_FN_LN) {
 521                     fld_len = FN_WIDTH_LN;
 522                     objbuf = OBJ_nid2ln(fn_nid);
 523                 } else {
 524                     fld_len = 0; /* XXX: what should this be? */
 525                     objbuf = "";
 526                 }
 527             }
 528             objlen = strlen(objbuf);
 529             if (!io_ch(arg, objbuf, objlen))
 530                 return -1;
 531             if ((objlen < fld_len) && (flags & XN_FLAG_FN_ALIGN)) {
 532                 if (!do_indent(io_ch, arg, fld_len - objlen))
 533                     return -1;
 534                 outlen += fld_len - objlen;
 535             }
 536             if (!io_ch(arg, sep_eq, sep_eq_len))
 537                 return -1;
 538             outlen += objlen + sep_eq_len;
 539         }
 540         /*
 541          * If the field name is unknown then fix up the DER dump flag. We
 542          * might want to limit this further so it will DER dump on anything
 543          * other than a few 'standard' fields.
 544          */
 545         if ((fn_nid == NID_undef) && (flags & XN_FLAG_DUMP_UNKNOWN_FIELDS))
 546             orflags = ASN1_STRFLGS_DUMP_ALL;
 547         else
 548             orflags = 0;
 549
 550         len = do_print_ex(io_ch, arg, flags | orflags, val);
 551         if (len < 0)
 552             return -1;
 553         outlen += len;
 554     }
 555     return outlen;
 556 }
 557
 558 /* Wrappers round the main functions */
 559
 560 int X509_NAME_print_ex(BIO *out, const X509_NAME *nm, int indent,
 561                        unsigned long flags)
 562 {
 563     if (flags == XN_FLAG_COMPAT)
 564         return X509_NAME_print(out, nm, indent);
 565     return do_name_ex(send_bio_chars, out, nm, indent, flags);
 566 }
 567
 568 #ifndef OPENSSL_NO_STDIO
 569 int X509_NAME_print_ex_fp(FILE *fp, const X509_NAME *nm, int indent,
 570                           unsigned long flags)
 571 {
 572     if (flags == XN_FLAG_COMPAT) {
 573         BIO *btmp;
 574         int ret;
 575         btmp = BIO_new_fp(fp, BIO_NOCLOSE);
 576         if (!btmp)
 577             return -1;
 578         ret = X509_NAME_print(btmp, nm, indent);
 579         BIO_free(btmp);
 580         return ret;
 581     }
 582     return do_name_ex(send_fp_chars, fp, nm, indent, flags);
 583 }
 584 #endif
 585
 586 int ASN1_STRING_print_ex(BIO *out, const ASN1_STRING *str, unsigned long flags)
 587 {
 588     return do_print_ex(send_bio_chars, out, flags, str);
 589 }
 590
 591 #ifndef OPENSSL_NO_STDIO
 592 int ASN1_STRING_print_ex_fp(FILE *fp, const ASN1_STRING *str, unsigned long flags)
 593 {
 594     return do_print_ex(send_fp_chars, fp, flags, str);
 595 }
 596 #endif
 597
 598 /*
 599  * Utility function: convert any string type to UTF8, returns number of bytes
 600  * in output string or a negative error code
 601  */
 602
 603 int ASN1_STRING_to_UTF8(unsigned char **out, const ASN1_STRING *in)
 604 {
 605     ASN1_STRING stmp, *str = &stmp;
 606     int mbflag, type, ret;
 607     if (!in)
 608         return -1;
 609     type = in->type;
 610     if ((type < 0) || (type > 30))
 611         return -1;
 612     mbflag = tag2nbyte[type];
 613     if (mbflag == -1)
 614         return -1;
 615     mbflag |= MBSTRING_FLAG;
 616     stmp.data = NULL;
 617     stmp.length = 0;
 618     stmp.flags = 0;
 619     ret =
 620         ASN1_mbstring_copy(&str, in->data, in->length, mbflag,
 621                            B_ASN1_UTF8STRING);
 622     if (ret < 0)
 623         return ret;
 624     *out = stmp.data;
 625     return stmp.length;
 626 }