crypto/bio/b_print.c

   1 /*
   2  * Copyright 1995-2017 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 #include <stdio.h>
  11 #include <string.h>
  12 #include "internal/ctype.h"
  13 #include "internal/numbers.h"
  14 #include "internal/cryptlib.h"
  15 #include <openssl/bio.h>
  16
  17 /*
  18  * Copyright Patrick Powell 1995
  19  * This code is based on code written by Patrick Powell <papowell@astart.com>
  20  * It may be used for any purpose as long as this notice remains intact
  21  * on all source code distributions.
  22  */
  23
  24 #ifdef HAVE_LONG_DOUBLE
  25 # define LDOUBLE long double
  26 #else
  27 # define LDOUBLE double
  28 #endif
  29
  30 static int fmtstr(char **, char **, size_t *, size_t *,
  31                   const char *, int, int, int);
  32 static int fmtint(char **, char **, size_t *, size_t *,
  33                   int64_t, int, int, int, int);
  34 static int fmtfp(char **, char **, size_t *, size_t *,
  35                  LDOUBLE, int, int, int, int);
  36 static int doapr_outch(char **, char **, size_t *, size_t *, int);
  37 static int _dopr(char **sbuffer, char **buffer,
  38                  size_t *maxlen, size_t *retlen, int *truncated,
  39                  const char *format, va_list args);
  40
  41 /* format read states */
  42 #define DP_S_DEFAULT    0
  43 #define DP_S_FLAGS      1
  44 #define DP_S_MIN        2
  45 #define DP_S_DOT        3
  46 #define DP_S_MAX        4
  47 #define DP_S_MOD        5
  48 #define DP_S_CONV       6
  49 #define DP_S_DONE       7
  50
  51 /* format flags - Bits */
  52 /* left-aligned padding */
  53 #define DP_F_MINUS      (1 << 0)
  54 /* print an explicit '+' for a value with positive sign */
  55 #define DP_F_PLUS       (1 << 1)
  56 /* print an explicit ' ' for a value with positive sign */
  57 #define DP_F_SPACE      (1 << 2)
  58 /* print 0/0x prefix for octal/hex and decimal point for floating point */
  59 #define DP_F_NUM        (1 << 3)
  60 /* print leading zeroes */
  61 #define DP_F_ZERO       (1 << 4)
  62 /* print HEX in UPPPERcase */
  63 #define DP_F_UP         (1 << 5)
  64 /* treat value as unsigned */
  65 #define DP_F_UNSIGNED   (1 << 6)
  66
  67 /* conversion flags */
  68 #define DP_C_SHORT      1
  69 #define DP_C_LONG       2
  70 #define DP_C_LDOUBLE    3
  71 #define DP_C_LLONG      4
  72 #define DP_C_SIZE       5
  73
  74 /* Floating point formats */
  75 #define F_FORMAT        0
  76 #define E_FORMAT        1
  77 #define G_FORMAT        2
  78
  79 /* some handy macros */
  80 #define char_to_int(p) (p - '0')
  81 #define OSSL_MAX(p,q) ((p >= q) ? p : q)
  82
  83 static int
  84 _dopr(char **sbuffer,
  85       char **buffer,
  86       size_t *maxlen,
  87       size_t *retlen, int *truncated, const char *format, va_list args)
  88 {
  89     char ch;
  90     int64_t value;
  91     LDOUBLE fvalue;
  92     char *strvalue;
  93     int min;
  94     int max;
  95     int state;
  96     int flags;
  97     int cflags;
  98     size_t currlen;
  99
 100     state = DP_S_DEFAULT;
 101     flags = currlen = cflags = min = 0;
 102     max = -1;
 103     ch = *format++;
 104
 105     while (state != DP_S_DONE) {
 106         if (ch == '\0' || (buffer == NULL && currlen >= *maxlen))
 107             state = DP_S_DONE;
 108
 109         switch (state) {
 110         case DP_S_DEFAULT:
 111             if (ch == '%')
 112                 state = DP_S_FLAGS;
 113             else
 114                 if(!doapr_outch(sbuffer, buffer, &currlen, maxlen, ch))
 115                     return 0;
 116             ch = *format++;
 117             break;
 118         case DP_S_FLAGS:
 119             switch (ch) {
 120             case '-':
 121                 flags |= DP_F_MINUS;
 122                 ch = *format++;
 123                 break;
 124             case '+':
 125                 flags |= DP_F_PLUS;
 126                 ch = *format++;
 127                 break;
 128             case ' ':
 129                 flags |= DP_F_SPACE;
 130                 ch = *format++;
 131                 break;
 132             case '#':
 133                 flags |= DP_F_NUM;
 134                 ch = *format++;
 135                 break;
 136             case '0':
 137                 flags |= DP_F_ZERO;
 138                 ch = *format++;
 139                 break;
 140             default:
 141                 state = DP_S_MIN;
 142                 break;
 143             }
 144             break;
 145         case DP_S_MIN:
 146             if (ossl_isdigit(ch)) {
 147                 min = 10 * min + char_to_int(ch);
 148                 ch = *format++;
 149             } else if (ch == '*') {
 150                 min = va_arg(args, int);
 151                 ch = *format++;
 152                 state = DP_S_DOT;
 153             } else
 154                 state = DP_S_DOT;
 155             break;
 156         case DP_S_DOT:
 157             if (ch == '.') {
 158                 state = DP_S_MAX;
 159                 ch = *format++;
 160             } else
 161                 state = DP_S_MOD;
 162             break;
 163         case DP_S_MAX:
 164             if (ossl_isdigit(ch)) {
 165                 if (max < 0)
 166                     max = 0;
 167                 max = 10 * max + char_to_int(ch);
 168                 ch = *format++;
 169             } else if (ch == '*') {
 170                 max = va_arg(args, int);
 171                 ch = *format++;
 172                 state = DP_S_MOD;
 173             } else
 174                 state = DP_S_MOD;
 175             break;
 176         case DP_S_MOD:
 177             switch (ch) {
 178             case 'h':
 179                 cflags = DP_C_SHORT;
 180                 ch = *format++;
 181                 break;
 182             case 'l':
 183                 if (*format == 'l') {
 184                     cflags = DP_C_LLONG;
 185                     format++;
 186                 } else
 187                     cflags = DP_C_LONG;
 188                 ch = *format++;
 189                 break;
 190             case 'q':
 191             case 'j':
 192                 cflags = DP_C_LLONG;
 193                 ch = *format++;
 194                 break;
 195             case 'L':
 196                 cflags = DP_C_LDOUBLE;
 197                 ch = *format++;
 198                 break;
 199             case 'z':
 200                 cflags = DP_C_SIZE;
 201                 ch = *format++;
 202                 break;
 203             default:
 204                 break;
 205             }
 206             state = DP_S_CONV;
 207             break;
 208         case DP_S_CONV:
 209             switch (ch) {
 210             case 'd':
 211             case 'i':
 212                 switch (cflags) {
 213                 case DP_C_SHORT:
 214                     value = (short int)va_arg(args, int);
 215                     break;
 216                 case DP_C_LONG:
 217                     value = va_arg(args, long int);
 218                     break;
 219                 case DP_C_LLONG:
 220                     value = va_arg(args, int64_t);
 221                     break;
 222                 case DP_C_SIZE:
 223                     value = va_arg(args, ossl_ssize_t);
 224                     break;
 225                 default:
 226                     value = va_arg(args, int);
 227                     break;
 228                 }
 229                 if (!fmtint(sbuffer, buffer, &currlen, maxlen, value, 10, min,
 230                             max, flags))
 231                     return 0;
 232                 break;
 233             case 'X':
 234                 flags |= DP_F_UP;
 235                 /* FALLTHROUGH */
 236             case 'x':
 237             case 'o':
 238             case 'u':
 239                 flags |= DP_F_UNSIGNED;
 240                 switch (cflags) {
 241                 case DP_C_SHORT:
 242                     value = (unsigned short int)va_arg(args, unsigned int);
 243                     break;
 244                 case DP_C_LONG:
 245                     value = va_arg(args, unsigned long int);
 246                     break;
 247                 case DP_C_LLONG:
 248                     value = va_arg(args, uint64_t);
 249                     break;
 250                 case DP_C_SIZE:
 251                     value = va_arg(args, size_t);
 252                     break;
 253                 default:
 254                     value = va_arg(args, unsigned int);
 255                     break;
 256                 }
 257                 if (!fmtint(sbuffer, buffer, &currlen, maxlen, value,
 258                             ch == 'o' ? 8 : (ch == 'u' ? 10 : 16),
 259                             min, max, flags))
 260                     return 0;
 261                 break;
 262             case 'f':
 263                 if (cflags == DP_C_LDOUBLE)
 264                     fvalue = va_arg(args, LDOUBLE);
 265                 else
 266                     fvalue = va_arg(args, double);
 267                 if (!fmtfp(sbuffer, buffer, &currlen, maxlen, fvalue, min, max,
 268                            flags, F_FORMAT))
 269                     return 0;
 270                 break;
 271             case 'E':
 272                 flags |= DP_F_UP;
 273                 /* fall thru */
 274             case 'e':
 275                 if (cflags == DP_C_LDOUBLE)
 276                     fvalue = va_arg(args, LDOUBLE);
 277                 else
 278                     fvalue = va_arg(args, double);
 279                 if (!fmtfp(sbuffer, buffer, &currlen, maxlen, fvalue, min, max,
 280                            flags, E_FORMAT))
 281                     return 0;
 282                 break;
 283             case 'G':
 284                 flags |= DP_F_UP;
 285                 /* fall thru */
 286             case 'g':
 287                 if (cflags == DP_C_LDOUBLE)
 288                     fvalue = va_arg(args, LDOUBLE);
 289                 else
 290                     fvalue = va_arg(args, double);
 291                 if (!fmtfp(sbuffer, buffer, &currlen, maxlen, fvalue, min, max,
 292                            flags, G_FORMAT))
 293                     return 0;
 294                 break;
 295             case 'c':
 296                 if(!doapr_outch(sbuffer, buffer, &currlen, maxlen,
 297                             va_arg(args, int)))
 298                     return 0;
 299                 break;
 300             case 's':
 301                 strvalue = va_arg(args, char *);
 302                 if (max < 0) {
 303                     if (buffer)
 304                         max = INT_MAX;
 305                     else
 306                         max = *maxlen;
 307                 }
 308                 if (!fmtstr(sbuffer, buffer, &currlen, maxlen, strvalue,
 309                             flags, min, max))
 310                     return 0;
 311                 break;
 312             case 'p':
 313                 value = (size_t)va_arg(args, void *);
 314                 if (!fmtint(sbuffer, buffer, &currlen, maxlen,
 315                             value, 16, min, max, flags | DP_F_NUM))
 316                     return 0;
 317                 break;
 318             case 'n':
 319                 {
 320                     int *num;
 321                     num = va_arg(args, int *);
 322                     *num = currlen;
 323                 }
 324                 break;
 325             case '%':
 326                 if(!doapr_outch(sbuffer, buffer, &currlen, maxlen, ch))
 327                     return 0;
 328                 break;
 329             case 'w':
 330                 /* not supported yet, treat as next char */
 331                 ch = *format++;
 332                 break;
 333             default:
 334                 /* unknown, skip */
 335                 break;
 336             }
 337             ch = *format++;
 338             state = DP_S_DEFAULT;
 339             flags = cflags = min = 0;
 340             max = -1;
 341             break;
 342         case DP_S_DONE:
 343             break;
 344         default:
 345             break;
 346         }
 347     }
 348     /*
 349      * We have to truncate if there is no dynamic buffer and we have filled the
 350      * static buffer.
 351      */
 352     if (buffer == NULL) {
 353         *truncated = (currlen > *maxlen - 1);
 354         if (*truncated)
 355             currlen = *maxlen - 1;
 356     }
 357     if(!doapr_outch(sbuffer, buffer, &currlen, maxlen, '\0'))
 358         return 0;
 359     *retlen = currlen - 1;
 360     return 1;
 361 }
 362
 363 static int
 364 fmtstr(char **sbuffer,
 365        char **buffer,
 366        size_t *currlen,
 367        size_t *maxlen, const char *value, int flags, int min, int max)
 368 {
 369     int padlen;
 370     size_t strln;
 371     int cnt = 0;
 372
 373     if (value == 0)
 374         value = "<NULL>";
 375
 376     strln = OPENSSL_strnlen(value, max < 0 ? SIZE_MAX : (size_t)max);
 377
 378     padlen = min - strln;
 379     if (min < 0 || padlen < 0)
 380         padlen = 0;
 381     if (max >= 0) {
 382         /*
 383          * Calculate the maximum output including padding.
 384          * Make sure max doesn't overflow into negativity
 385          */
 386         if (max < INT_MAX - padlen)
 387             max += padlen;
 388         else
 389             max = INT_MAX;
 390     }
 391     if (flags & DP_F_MINUS)
 392         padlen = -padlen;
 393
 394     while ((padlen > 0) && (max < 0 || cnt < max)) {
 395         if(!doapr_outch(sbuffer, buffer, currlen, maxlen, ' '))
 396             return 0;
 397         --padlen;
 398         ++cnt;
 399     }
 400     while (strln > 0 && (max < 0 || cnt < max)) {
 401         if(!doapr_outch(sbuffer, buffer, currlen, maxlen, *value++))
 402             return 0;
 403         --strln;
 404         ++cnt;
 405     }
 406     while ((padlen < 0) && (max < 0 || cnt < max)) {
 407         if(!doapr_outch(sbuffer, buffer, currlen, maxlen, ' '))
 408             return 0;
 409         ++padlen;
 410         ++cnt;
 411     }
 412     return 1;
 413 }
 414
 415 static int
 416 fmtint(char **sbuffer,
 417        char **buffer,
 418        size_t *currlen,
 419        size_t *maxlen, int64_t value, int base, int min, int max, int flags)
 420 {
 421     int signvalue = 0;
 422     const char *prefix = "";
 423     uint64_t uvalue;
 424     char convert[DECIMAL_SIZE(value) + 3];
 425     int place = 0;
 426     int spadlen = 0;
 427     int zpadlen = 0;
 428     int caps = 0;
 429
 430     if (max < 0)
 431         max = 0;
 432     uvalue = value;
 433     if (!(flags & DP_F_UNSIGNED)) {
 434         if (value < 0) {
 435             signvalue = '-';
 436             uvalue = 0 - (uint64_t)value;
 437         } else if (flags & DP_F_PLUS)
 438             signvalue = '+';
 439         else if (flags & DP_F_SPACE)
 440             signvalue = ' ';
 441     }
 442     if (flags & DP_F_NUM) {
 443         if (base == 8)
 444             prefix = "0";
 445         if (base == 16)
 446             prefix = "0x";
 447     }
 448     if (flags & DP_F_UP)
 449         caps = 1;
 450     do {
 451         convert[place++] = (caps ? "0123456789ABCDEF" : "0123456789abcdef")
 452             [uvalue % (unsigned)base];
 453         uvalue = (uvalue / (unsigned)base);
 454     } while (uvalue && (place < (int)sizeof(convert)));
 455     if (place == sizeof(convert))
 456         place--;
 457     convert[place] = 0;
 458
 459     zpadlen = max - place;
 460     spadlen =
 461         min - OSSL_MAX(max, place) - (signvalue ? 1 : 0) - strlen(prefix);
 462     if (zpadlen < 0)
 463         zpadlen = 0;
 464     if (spadlen < 0)
 465         spadlen = 0;
 466     if (flags & DP_F_ZERO) {
 467         zpadlen = OSSL_MAX(zpadlen, spadlen);
 468         spadlen = 0;
 469     }
 470     if (flags & DP_F_MINUS)
 471         spadlen = -spadlen;
 472
 473     /* spaces */
 474     while (spadlen > 0) {
 475         if(!doapr_outch(sbuffer, buffer, currlen, maxlen, ' '))
 476             return 0;
 477         --spadlen;
 478     }
 479
 480     /* sign */
 481     if (signvalue)
 482         if(!doapr_outch(sbuffer, buffer, currlen, maxlen, signvalue))
 483             return 0;
 484
 485     /* prefix */
 486     while (*prefix) {
 487         if(!doapr_outch(sbuffer, buffer, currlen, maxlen, *prefix))
 488             return 0;
 489         prefix++;
 490     }
 491
 492     /* zeros */
 493     if (zpadlen > 0) {
 494         while (zpadlen > 0) {
 495             if(!doapr_outch(sbuffer, buffer, currlen, maxlen, '0'))
 496                 return 0;
 497             --zpadlen;
 498         }
 499     }
 500     /* digits */
 501     while (place > 0) {
 502         if (!doapr_outch(sbuffer, buffer, currlen, maxlen, convert[--place]))
 503             return 0;
 504     }
 505
 506     /* left justified spaces */
 507     while (spadlen < 0) {
 508         if (!doapr_outch(sbuffer, buffer, currlen, maxlen, ' '))
 509             return 0;
 510         ++spadlen;
 511     }
 512     return 1;
 513 }
 514
 515 static LDOUBLE abs_val(LDOUBLE value)
 516 {
 517     LDOUBLE result = value;
 518     if (value < 0)
 519         result = -value;
 520     return result;
 521 }
 522
 523 static LDOUBLE pow_10(int in_exp)
 524 {
 525     LDOUBLE result = 1;
 526     while (in_exp) {
 527         result *= 10;
 528         in_exp--;
 529     }
 530     return result;
 531 }
 532
 533 static long roundv(LDOUBLE value)
 534 {
 535     long intpart;
 536     intpart = (long)value;
 537     value = value - intpart;
 538     if (value >= 0.5)
 539         intpart++;
 540     return intpart;
 541 }
 542
 543 static int
 544 fmtfp(char **sbuffer,
 545       char **buffer,
 546       size_t *currlen,
 547       size_t *maxlen, LDOUBLE fvalue, int min, int max, int flags, int style)
 548 {
 549     int signvalue = 0;
 550     LDOUBLE ufvalue;
 551     LDOUBLE tmpvalue;
 552     char iconvert[20];
 553     char fconvert[20];
 554     char econvert[20];
 555     int iplace = 0;
 556     int fplace = 0;
 557     int eplace = 0;
 558     int padlen = 0;
 559     int zpadlen = 0;
 560     long exp = 0;
 561     unsigned long intpart;
 562     unsigned long fracpart;
 563     unsigned long max10;
 564     int realstyle;
 565
 566     if (max < 0)
 567         max = 6;
 568
 569     if (fvalue < 0)
 570         signvalue = '-';
 571     else if (flags & DP_F_PLUS)
 572         signvalue = '+';
 573     else if (flags & DP_F_SPACE)
 574         signvalue = ' ';
 575
 576     /*
 577      * G_FORMAT sometimes prints like E_FORMAT and sometimes like F_FORMAT
 578      * depending on the number to be printed. Work out which one it is and use
 579      * that from here on.
 580      */
 581     if (style == G_FORMAT) {
 582         if (fvalue == 0.0) {
 583             realstyle = F_FORMAT;
 584         } else if (fvalue < 0.0001) {
 585             realstyle = E_FORMAT;
 586         } else if ((max == 0 && fvalue >= 10)
 587                     || (max > 0 && fvalue >= pow_10(max))) {
 588             realstyle = E_FORMAT;
 589         } else {
 590             realstyle = F_FORMAT;
 591         }
 592     } else {
 593         realstyle = style;
 594     }
 595
 596     if (style != F_FORMAT) {
 597         tmpvalue = fvalue;
 598         /* Calculate the exponent */
 599         if (fvalue != 0.0) {
 600             while (tmpvalue < 1) {
 601                 tmpvalue *= 10;
 602                 exp--;
 603             }
 604             while (tmpvalue > 10) {
 605                 tmpvalue /= 10;
 606                 exp++;
 607             }
 608         }
 609         if (style == G_FORMAT) {
 610             /*
 611              * In G_FORMAT the "precision" represents significant digits. We
 612              * always have at least 1 significant digit.
 613              */
 614             if (max == 0)
 615                 max = 1;
 616             /* Now convert significant digits to decimal places */
 617             if (realstyle == F_FORMAT) {
 618                 max -= (exp + 1);
 619                 if (max < 0) {
 620                     /*
 621                      * Should not happen. If we're in F_FORMAT then exp < max?
 622                      */
 623                     return 0;
 624                 }
 625             } else {
 626                 /*
 627                  * In E_FORMAT there is always one significant digit in front
 628                  * of the decimal point, so:
 629                  * significant digits == 1 + decimal places
 630                  */
 631                 max--;
 632             }
 633         }
 634         if (realstyle == E_FORMAT)
 635             fvalue = tmpvalue;
 636     }
 637     ufvalue = abs_val(fvalue);
 638     if (ufvalue > ULONG_MAX) {
 639         /* Number too big */
 640         return 0;
 641     }
 642     intpart = (unsigned long)ufvalue;
 643
 644     /*
 645      * sorry, we only support 9 digits past the decimal because of our
 646      * conversion method
 647      */
 648     if (max > 9)
 649         max = 9;
 650
 651     /*
 652      * we "cheat" by converting the fractional part to integer by multiplying
 653      * by a factor of 10
 654      */
 655     max10 = roundv(pow_10(max));
 656     fracpart = roundv(pow_10(max) * (ufvalue - intpart));
 657
 658     if (fracpart >= max10) {
 659         intpart++;
 660         fracpart -= max10;
 661     }
 662
 663     /* convert integer part */
 664     do {
 665         iconvert[iplace++] = "0123456789"[intpart % 10];
 666         intpart = (intpart / 10);
 667     } while (intpart && (iplace < (int)sizeof(iconvert)));
 668     if (iplace == sizeof iconvert)
 669         iplace--;
 670     iconvert[iplace] = 0;
 671
 672     /* convert fractional part */
 673     while (fplace < max) {
 674         if (style == G_FORMAT && fplace == 0 && (fracpart % 10) == 0) {
 675             /* We strip trailing zeros in G_FORMAT */
 676             max--;
 677             fracpart = fracpart / 10;
 678             if (fplace < max)
 679                 continue;
 680             break;
 681         }
 682         fconvert[fplace++] = "0123456789"[fracpart % 10];
 683         fracpart = (fracpart / 10);
 684     }
 685
 686     if (fplace == sizeof fconvert)
 687         fplace--;
 688     fconvert[fplace] = 0;
 689
 690     /* convert exponent part */
 691     if (realstyle == E_FORMAT) {
 692         int tmpexp;
 693         if (exp < 0)
 694             tmpexp = -exp;
 695         else
 696             tmpexp = exp;
 697
 698         do {
 699             econvert[eplace++] = "0123456789"[tmpexp % 10];
 700             tmpexp = (tmpexp / 10);
 701         } while (tmpexp > 0 && eplace < (int)sizeof(econvert));
 702         /* Exponent is huge!! Too big to print */
 703         if (tmpexp > 0)
 704             return 0;
 705         /* Add a leading 0 for single digit exponents */
 706         if (eplace == 1)
 707             econvert[eplace++] = '0';
 708     }
 709
 710     /*
 711      * -1 for decimal point (if we have one, i.e. max > 0),
 712      * another -1 if we are printing a sign
 713      */
 714     padlen = min - iplace - max - (max > 0 ? 1 : 0) - ((signvalue) ? 1 : 0);
 715     /* Take some off for exponent prefix "+e" and exponent */
 716     if (realstyle == E_FORMAT)
 717         padlen -= 2 + eplace;
 718     zpadlen = max - fplace;
 719     if (zpadlen < 0)
 720         zpadlen = 0;
 721     if (padlen < 0)
 722         padlen = 0;
 723     if (flags & DP_F_MINUS)
 724         padlen = -padlen;
 725
 726     if ((flags & DP_F_ZERO) && (padlen > 0)) {
 727         if (signvalue) {
 728             if (!doapr_outch(sbuffer, buffer, currlen, maxlen, signvalue))
 729                 return 0;
 730             --padlen;
 731             signvalue = 0;
 732         }
 733         while (padlen > 0) {
 734             if (!doapr_outch(sbuffer, buffer, currlen, maxlen, '0'))
 735                 return 0;
 736             --padlen;
 737         }
 738     }
 739     while (padlen > 0) {
 740         if (!doapr_outch(sbuffer, buffer, currlen, maxlen, ' '))
 741             return 0;
 742         --padlen;
 743     }
 744     if (signvalue && !doapr_outch(sbuffer, buffer, currlen, maxlen, signvalue))
 745         return 0;
 746
 747     while (iplace > 0) {
 748         if (!doapr_outch(sbuffer, buffer, currlen, maxlen, iconvert[--iplace]))
 749             return 0;
 750     }
 751
 752     /*
 753      * Decimal point. This should probably use locale to find the correct
 754      * char to print out.
 755      */
 756     if (max > 0 || (flags & DP_F_NUM)) {
 757         if (!doapr_outch(sbuffer, buffer, currlen, maxlen, '.'))
 758             return 0;
 759
 760         while (fplace > 0) {
 761             if(!doapr_outch(sbuffer, buffer, currlen, maxlen,
 762                             fconvert[--fplace]))
 763                 return 0;
 764         }
 765     }
 766     while (zpadlen > 0) {
 767         if (!doapr_outch(sbuffer, buffer, currlen, maxlen, '0'))
 768             return 0;
 769         --zpadlen;
 770     }
 771     if (realstyle == E_FORMAT) {
 772         char ech;
 773
 774         if ((flags & DP_F_UP) == 0)
 775             ech = 'e';
 776         else
 777             ech = 'E';
 778         if (!doapr_outch(sbuffer, buffer, currlen, maxlen, ech))
 779                 return 0;
 780         if (exp < 0) {
 781             if (!doapr_outch(sbuffer, buffer, currlen, maxlen, '-'))
 782                     return 0;
 783         } else {
 784             if (!doapr_outch(sbuffer, buffer, currlen, maxlen, '+'))
 785                     return 0;
 786         }
 787         while (eplace > 0) {
 788             if (!doapr_outch(sbuffer, buffer, currlen, maxlen,
 789                              econvert[--eplace]))
 790                 return 0;
 791         }
 792     }
 793
 794     while (padlen < 0) {
 795         if (!doapr_outch(sbuffer, buffer, currlen, maxlen, ' '))
 796             return 0;
 797         ++padlen;
 798     }
 799     return 1;
 800 }
 801
 802 #define BUFFER_INC  1024
 803
 804 static int
 805 doapr_outch(char **sbuffer,
 806             char **buffer, size_t *currlen, size_t *maxlen, int c)
 807 {
 808     /* If we haven't at least one buffer, someone has done a big booboo */
 809     if (!ossl_assert(*sbuffer != NULL || buffer != NULL))
 810         return 0;
 811
 812     /* |currlen| must always be <= |*maxlen| */
 813     if (!ossl_assert(*currlen <= *maxlen))
 814         return 0;
 815
 816     if (buffer && *currlen == *maxlen) {
 817         if (*maxlen > INT_MAX - BUFFER_INC)
 818             return 0;
 819
 820         *maxlen += BUFFER_INC;
 821         if (*buffer == NULL) {
 822             *buffer = OPENSSL_malloc(*maxlen);
 823             if (*buffer == NULL)
 824                 return 0;
 825             if (*currlen > 0) {
 826                 if (!ossl_assert(*sbuffer != NULL))
 827                     return 0;
 828                 memcpy(*buffer, *sbuffer, *currlen);
 829             }
 830             *sbuffer = NULL;
 831         } else {
 832             char *tmpbuf;
 833             tmpbuf = OPENSSL_realloc(*buffer, *maxlen);
 834             if (tmpbuf == NULL)
 835                 return 0;
 836             *buffer = tmpbuf;
 837         }
 838     }
 839
 840     if (*currlen < *maxlen) {
 841         if (*sbuffer)
 842             (*sbuffer)[(*currlen)++] = (char)c;
 843         else
 844             (*buffer)[(*currlen)++] = (char)c;
 845     }
 846
 847     return 1;
 848 }
 849
 850 /***************************************************************************/
 851
 852 int BIO_printf(BIO *bio, const char *format, ...)
 853 {
 854     va_list args;
 855     int ret;
 856
 857     va_start(args, format);
 858
 859     ret = BIO_vprintf(bio, format, args);
 860
 861     va_end(args);
 862     return ret;
 863 }
 864
 865 int BIO_vprintf(BIO *bio, const char *format, va_list args)
 866 {
 867     int ret;
 868     size_t retlen;
 869     char hugebuf[1024 * 2];     /* Was previously 10k, which is unreasonable
 870                                  * in small-stack environments, like threads
 871                                  * or DOS programs. */
 872     char *hugebufp = hugebuf;
 873     size_t hugebufsize = sizeof(hugebuf);
 874     char *dynbuf = NULL;
 875     int ignored;
 876
 877     dynbuf = NULL;
 878     if (!_dopr(&hugebufp, &dynbuf, &hugebufsize, &retlen, &ignored, format,
 879                 args)) {
 880         OPENSSL_free(dynbuf);
 881         return -1;
 882     }
 883     if (dynbuf) {
 884         ret = BIO_write(bio, dynbuf, (int)retlen);
 885         OPENSSL_free(dynbuf);
 886     } else {
 887         ret = BIO_write(bio, hugebuf, (int)retlen);
 888     }
 889     return ret;
 890 }
 891
 892 /*
 893  * As snprintf is not available everywhere, we provide our own
 894  * implementation. This function has nothing to do with BIOs, but it's
 895  * closely related to BIO_printf, and we need *some* name prefix ... (XXX the
 896  * function should be renamed, but to what?)
 897  */
 898 int BIO_snprintf(char *buf, size_t n, const char *format, ...)
 899 {
 900     va_list args;
 901     int ret;
 902
 903     va_start(args, format);
 904
 905     ret = BIO_vsnprintf(buf, n, format, args);
 906
 907     va_end(args);
 908     return ret;
 909 }
 910
 911 int BIO_vsnprintf(char *buf, size_t n, const char *format, va_list args)
 912 {
 913     size_t retlen;
 914     int truncated;
 915
 916     if(!_dopr(&buf, NULL, &n, &retlen, &truncated, format, args))
 917         return -1;
 918
 919     if (truncated)
 920         /*
 921          * In case of truncation, return -1 like traditional snprintf.
 922          * (Current drafts for ISO/IEC 9899 say snprintf should return the
 923          * number of characters that would have been written, had the buffer
 924          * been large enough.)
 925          */
 926         return -1;
 927     else
 928         return (retlen <= INT_MAX) ? (int)retlen : -1;
 929 }