crypto/bio/bf_lbuf.c

   1 /*
   2  * Copyright 1995-2018 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 <errno.h>
  12 #include "bio_local.h"
  13 #include "internal/cryptlib.h"
  14 #include <openssl/evp.h>
  15
  16 static int linebuffer_write(BIO *h, const char *buf, int num);
  17 static int linebuffer_read(BIO *h, char *buf, int size);
  18 static int linebuffer_puts(BIO *h, const char *str);
  19 static int linebuffer_gets(BIO *h, char *str, int size);
  20 static long linebuffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  21 static int linebuffer_new(BIO *h);
  22 static int linebuffer_free(BIO *data);
  23 static long linebuffer_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
  24
  25 /* A 10k maximum should be enough for most purposes */
  26 #define DEFAULT_LINEBUFFER_SIZE 1024*10
  27
  28 /* #define DEBUG */
  29
  30 static const BIO_METHOD methods_linebuffer = {
  31     BIO_TYPE_LINEBUFFER,
  32     "linebuffer",
  33     /* TODO: Convert to new style write function */
  34     bwrite_conv,
  35     linebuffer_write,
  36     /* TODO: Convert to new style read function */
  37     bread_conv,
  38     linebuffer_read,
  39     linebuffer_puts,
  40     linebuffer_gets,
  41     linebuffer_ctrl,
  42     linebuffer_new,
  43     linebuffer_free,
  44     linebuffer_callback_ctrl,
  45 };
  46
  47 const BIO_METHOD *BIO_f_linebuffer(void)
  48 {
  49     return &methods_linebuffer;
  50 }
  51
  52 typedef struct bio_linebuffer_ctx_struct {
  53     char *obuf;                 /* the output char array */
  54     int obuf_size;              /* how big is the output buffer */
  55     int obuf_len;               /* how many bytes are in it */
  56 } BIO_LINEBUFFER_CTX;
  57
  58 static int linebuffer_new(BIO *bi)
  59 {
  60     BIO_LINEBUFFER_CTX *ctx;
  61
  62     if ((ctx = OPENSSL_malloc(sizeof(*ctx))) == NULL) {
  63         BIOerr(BIO_F_LINEBUFFER_NEW, ERR_R_MALLOC_FAILURE);
  64         return 0;
  65     }
  66     ctx->obuf = OPENSSL_malloc(DEFAULT_LINEBUFFER_SIZE);
  67     if (ctx->obuf == NULL) {
  68         BIOerr(BIO_F_LINEBUFFER_NEW, ERR_R_MALLOC_FAILURE);
  69         OPENSSL_free(ctx);
  70         return 0;
  71     }
  72     ctx->obuf_size = DEFAULT_LINEBUFFER_SIZE;
  73     ctx->obuf_len = 0;
  74
  75     bi->init = 1;
  76     bi->ptr = (char *)ctx;
  77     bi->flags = 0;
  78     return 1;
  79 }
  80
  81 static int linebuffer_free(BIO *a)
  82 {
  83     BIO_LINEBUFFER_CTX *b;
  84
  85     if (a == NULL)
  86         return 0;
  87     b = (BIO_LINEBUFFER_CTX *)a->ptr;
  88     OPENSSL_free(b->obuf);
  89     OPENSSL_free(a->ptr);
  90     a->ptr = NULL;
  91     a->init = 0;
  92     a->flags = 0;
  93     return 1;
  94 }
  95
  96 static int linebuffer_read(BIO *b, char *out, int outl)
  97 {
  98     int ret = 0;
  99
 100     if (out == NULL)
 101         return 0;
 102     if (b->next_bio == NULL)
 103         return 0;
 104     ret = BIO_read(b->next_bio, out, outl);
 105     BIO_clear_retry_flags(b);
 106     BIO_copy_next_retry(b);
 107     return ret;
 108 }
 109
 110 static int linebuffer_write(BIO *b, const char *in, int inl)
 111 {
 112     int i, num = 0, foundnl;
 113     BIO_LINEBUFFER_CTX *ctx;
 114
 115     if ((in == NULL) || (inl <= 0))
 116         return 0;
 117     ctx = (BIO_LINEBUFFER_CTX *)b->ptr;
 118     if ((ctx == NULL) || (b->next_bio == NULL))
 119         return 0;
 120
 121     BIO_clear_retry_flags(b);
 122
 123     do {
 124         const char *p;
 125         char c;
 126
 127         for (p = in, c = '\0'; p < in + inl && (c = *p) != '\n'; p++) ;
 128         if (c == '\n') {
 129             p++;
 130             foundnl = 1;
 131         } else
 132             foundnl = 0;
 133
 134         /*
 135          * If a NL was found and we already have text in the save buffer,
 136          * concatenate them and write
 137          */
 138         while ((foundnl || p - in > ctx->obuf_size - ctx->obuf_len)
 139                && ctx->obuf_len > 0) {
 140             int orig_olen = ctx->obuf_len;
 141
 142             i = ctx->obuf_size - ctx->obuf_len;
 143             if (p - in > 0) {
 144                 if (i >= p - in) {
 145                     memcpy(&(ctx->obuf[ctx->obuf_len]), in, p - in);
 146                     ctx->obuf_len += p - in;
 147                     inl -= p - in;
 148                     num += p - in;
 149                     in = p;
 150                 } else {
 151                     memcpy(&(ctx->obuf[ctx->obuf_len]), in, i);
 152                     ctx->obuf_len += i;
 153                     inl -= i;
 154                     in += i;
 155                     num += i;
 156                 }
 157             }
 158             i = BIO_write(b->next_bio, ctx->obuf, ctx->obuf_len);
 159             if (i <= 0) {
 160                 ctx->obuf_len = orig_olen;
 161                 BIO_copy_next_retry(b);
 162
 163                 if (i < 0)
 164                     return ((num > 0) ? num : i);
 165                 if (i == 0)
 166                     return num;
 167             }
 168             if (i < ctx->obuf_len)
 169                 memmove(ctx->obuf, ctx->obuf + i, ctx->obuf_len - i);
 170             ctx->obuf_len -= i;
 171         }
 172
 173         /*
 174          * Now that the save buffer is emptied, let's write the input buffer
 175          * if a NL was found and there is anything to write.
 176          */
 177         if ((foundnl || p - in > ctx->obuf_size) && p - in > 0) {
 178             i = BIO_write(b->next_bio, in, p - in);
 179             if (i <= 0) {
 180                 BIO_copy_next_retry(b);
 181                 if (i < 0)
 182                     return ((num > 0) ? num : i);
 183                 if (i == 0)
 184                     return num;
 185             }
 186             num += i;
 187             in += i;
 188             inl -= i;
 189         }
 190     }
 191     while (foundnl && inl > 0);
 192     /*
 193      * We've written as much as we can.  The rest of the input buffer, if
 194      * any, is text that doesn't and with a NL and therefore needs to be
 195      * saved for the next trip.
 196      */
 197     if (inl > 0) {
 198         memcpy(&(ctx->obuf[ctx->obuf_len]), in, inl);
 199         ctx->obuf_len += inl;
 200         num += inl;
 201     }
 202     return num;
 203 }
 204
 205 static long linebuffer_ctrl(BIO *b, int cmd, long num, void *ptr)
 206 {
 207     BIO *dbio;
 208     BIO_LINEBUFFER_CTX *ctx;
 209     long ret = 1;
 210     char *p;
 211     int r;
 212     int obs;
 213
 214     ctx = (BIO_LINEBUFFER_CTX *)b->ptr;
 215
 216     switch (cmd) {
 217     case BIO_CTRL_RESET:
 218         ctx->obuf_len = 0;
 219         if (b->next_bio == NULL)
 220             return 0;
 221         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 222         break;
 223     case BIO_CTRL_INFO:
 224         ret = (long)ctx->obuf_len;
 225         break;
 226     case BIO_CTRL_WPENDING:
 227         ret = (long)ctx->obuf_len;
 228         if (ret == 0) {
 229             if (b->next_bio == NULL)
 230                 return 0;
 231             ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 232         }
 233         break;
 234     case BIO_C_SET_BUFF_SIZE:
 235         obs = (int)num;
 236         p = ctx->obuf;
 237         if ((obs > DEFAULT_LINEBUFFER_SIZE) && (obs != ctx->obuf_size)) {
 238             p = OPENSSL_malloc((int)num);
 239             if (p == NULL)
 240                 goto malloc_error;
 241         }
 242         if (ctx->obuf != p) {
 243             if (ctx->obuf_len > obs) {
 244                 ctx->obuf_len = obs;
 245             }
 246             memcpy(p, ctx->obuf, ctx->obuf_len);
 247             OPENSSL_free(ctx->obuf);
 248             ctx->obuf = p;
 249             ctx->obuf_size = obs;
 250         }
 251         break;
 252     case BIO_C_DO_STATE_MACHINE:
 253         if (b->next_bio == NULL)
 254             return 0;
 255         BIO_clear_retry_flags(b);
 256         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 257         BIO_copy_next_retry(b);
 258         break;
 259
 260     case BIO_CTRL_FLUSH:
 261         if (b->next_bio == NULL)
 262             return 0;
 263         if (ctx->obuf_len <= 0) {
 264             ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 265             break;
 266         }
 267
 268         for (;;) {
 269             BIO_clear_retry_flags(b);
 270             if (ctx->obuf_len > 0) {
 271                 r = BIO_write(b->next_bio, ctx->obuf, ctx->obuf_len);
 272                 BIO_copy_next_retry(b);
 273                 if (r <= 0)
 274                     return (long)r;
 275                 if (r < ctx->obuf_len)
 276                     memmove(ctx->obuf, ctx->obuf + r, ctx->obuf_len - r);
 277                 ctx->obuf_len -= r;
 278             } else {
 279                 ctx->obuf_len = 0;
 280                 break;
 281             }
 282         }
 283         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 284         break;
 285     case BIO_CTRL_DUP:
 286         dbio = (BIO *)ptr;
 287         if (!BIO_set_write_buffer_size(dbio, ctx->obuf_size))
 288             ret = 0;
 289         break;
 290     default:
 291         if (b->next_bio == NULL)
 292             return 0;
 293         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
 294         break;
 295     }
 296     return ret;
 297  malloc_error:
 298     BIOerr(BIO_F_LINEBUFFER_CTRL, ERR_R_MALLOC_FAILURE);
 299     return 0;
 300 }
 301
 302 static long linebuffer_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
 303 {
 304     long ret = 1;
 305
 306     if (b->next_bio == NULL)
 307         return 0;
 308     switch (cmd) {
 309     default:
 310         ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
 311         break;
 312     }
 313     return ret;
 314 }
 315
 316 static int linebuffer_gets(BIO *b, char *buf, int size)
 317 {
 318     if (b->next_bio == NULL)
 319         return 0;
 320     return BIO_gets(b->next_bio, buf, size);
 321 }
 322
 323 static int linebuffer_puts(BIO *b, const char *str)
 324 {
 325     return linebuffer_write(b, str, strlen(str));
 326 }