crypto/bio/bss_mem.c

   1 /*
   2  * Copyright 1995-2016 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 #include <stdio.h>
  11 #include <errno.h>
  12 #include "bio_lcl.h"
  13 #include "internal/cryptlib.h"
  14
  15 static int mem_write(BIO *h, const char *buf, int num);
  16 static int mem_read(BIO *h, char *buf, int size);
  17 static int mem_puts(BIO *h, const char *str);
  18 static int mem_gets(BIO *h, char *str, int size);
  19 static long mem_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  20 static int mem_new(BIO *h);
  21 static int secmem_new(BIO *h);
  22 static int mem_free(BIO *data);
  23 static int mem_buf_free(BIO *data, int free_all);
  24 static int mem_buf_sync(BIO *h);
  25
  26 static const BIO_METHOD mem_method = {
  27     BIO_TYPE_MEM,
  28     "memory buffer",
  29     /* TODO: Convert to new style write function */
  30     bwrite_conv,
  31     mem_write,
  32     /* TODO: Convert to new style read function */
  33     bread_conv,
  34     mem_read,
  35     mem_puts,
  36     mem_gets,
  37     mem_ctrl,
  38     mem_new,
  39     mem_free,
  40     NULL,
  41 };
  42
  43 static const BIO_METHOD secmem_method = {
  44     BIO_TYPE_MEM,
  45     "secure memory buffer",
  46     /* TODO: Convert to new style write function */
  47     bwrite_conv,
  48     mem_write,
  49     /* TODO: Convert to new style read function */
  50     bread_conv,
  51     mem_read,
  52     mem_puts,
  53     mem_gets,
  54     mem_ctrl,
  55     secmem_new,
  56     mem_free,
  57     NULL,
  58 };
  59
  60 /* BIO memory stores buffer and read pointer  */
  61 typedef struct bio_buf_mem_st {
  62     struct buf_mem_st *buf;   /* allocated buffer */
  63     struct buf_mem_st *readp; /* read pointer */
  64 } BIO_BUF_MEM;
  65
  66 /*
  67  * bio->num is used to hold the value to return on 'empty', if it is 0,
  68  * should_retry is not set
  69  */
  70
  71 const BIO_METHOD *BIO_s_mem(void)
  72 {
  73     return &mem_method;
  74 }
  75
  76 const BIO_METHOD *BIO_s_secmem(void)
  77 {
  78     return(&secmem_method);
  79 }
  80
  81 BIO *BIO_new_mem_buf(const void *buf, int len)
  82 {
  83     BIO *ret;
  84     BUF_MEM *b;
  85     BIO_BUF_MEM *bb;
  86     size_t sz;
  87
  88     if (buf == NULL) {
  89         BIOerr(BIO_F_BIO_NEW_MEM_BUF, BIO_R_NULL_PARAMETER);
  90         return NULL;
  91     }
  92     sz = (len < 0) ? strlen(buf) : (size_t)len;
  93     if ((ret = BIO_new(BIO_s_mem())) == NULL)
  94         return NULL;
  95     bb = (BIO_BUF_MEM *)ret->ptr;
  96     b = bb->buf;
  97     /* Cast away const and trust in the MEM_RDONLY flag. */
  98     b->data = (void *)buf;
  99     b->length = sz;
 100     b->max = sz;
 101     *bb->readp = *bb->buf;
 102     ret->flags |= BIO_FLAGS_MEM_RDONLY;
 103     /* Since this is static data retrying won't help */
 104     ret->num = 0;
 105     return ret;
 106 }
 107
 108 static int mem_init(BIO *bi, unsigned long flags)
 109 {
 110     BIO_BUF_MEM *bb = OPENSSL_zalloc(sizeof(*bb));
 111
 112     if (bb == NULL)
 113         return 0;
 114     if ((bb->buf = BUF_MEM_new_ex(flags)) == NULL) {
 115         OPENSSL_free(bb);
 116         return 0;
 117     }
 118     if ((bb->readp = OPENSSL_zalloc(sizeof(*bb->readp))) == NULL) {
 119         BUF_MEM_free(bb->buf);
 120         OPENSSL_free(bb);
 121         return 0;
 122     }
 123     *bb->readp = *bb->buf;
 124     bi->shutdown = 1;
 125     bi->init = 1;
 126     bi->num = -1;
 127     bi->ptr = (char *)bb;
 128     return 1;
 129 }
 130
 131 static int mem_new(BIO *bi)
 132 {
 133     return mem_init(bi, 0L);
 134 }
 135
 136 static int secmem_new(BIO *bi)
 137 {
 138     return mem_init(bi, BUF_MEM_FLAG_SECURE);
 139 }
 140
 141 static int mem_free(BIO *a)
 142 {
 143     return mem_buf_free(a, 1);
 144 }
 145
 146 static int mem_buf_free(BIO *a, int free_all)
 147 {
 148     if (a == NULL)
 149         return 0;
 150
 151     if (a->shutdown && a->init && a->ptr != NULL) {
 152         BIO_BUF_MEM *bb = (BIO_BUF_MEM *)a->ptr;
 153         BUF_MEM *b = bb->buf;
 154
 155         if (a->flags & BIO_FLAGS_MEM_RDONLY)
 156             b->data = NULL;
 157         BUF_MEM_free(b);
 158         if (free_all) {
 159             OPENSSL_free(bb->readp);
 160             OPENSSL_free(bb);
 161         }
 162         a->ptr = NULL;
 163     }
 164     return 1;
 165 }
 166
 167 /*
 168  * Reallocate memory buffer if read pointer differs
 169  */
 170 static int mem_buf_sync(BIO *b)
 171 {
 172     if (b != NULL && b->init != 0 && b->ptr != NULL) {
 173         BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
 174
 175         if (bbm->readp->data != bbm->buf->data) {
 176             memmove(bbm->buf->data, bbm->readp->data, bbm->readp->length);
 177             bbm->buf->length = bbm->readp->length;
 178             bbm->readp->data = bbm->buf->data;
 179         }
 180     }
 181     return 0;
 182 }
 183
 184 static int mem_read(BIO *b, char *out, int outl)
 185 {
 186     int ret = -1;
 187     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
 188     BUF_MEM *bm = bbm->readp;
 189
 190     BIO_clear_retry_flags(b);
 191     ret = (outl >= 0 && (size_t)outl > bm->length) ? (int)bm->length : outl;
 192     if ((out != NULL) && (ret > 0)) {
 193         memcpy(out, bm->data, ret);
 194         bm->length -= ret;
 195         bm->data += ret;
 196     } else if (bm->length == 0) {
 197         ret = b->num;
 198         if (ret != 0)
 199             BIO_set_retry_read(b);
 200     }
 201     return ret;
 202 }
 203
 204 static int mem_write(BIO *b, const char *in, int inl)
 205 {
 206     int ret = -1;
 207     int blen;
 208     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
 209
 210     if (in == NULL) {
 211         BIOerr(BIO_F_MEM_WRITE, BIO_R_NULL_PARAMETER);
 212         goto end;
 213     }
 214     if (b->flags & BIO_FLAGS_MEM_RDONLY) {
 215         BIOerr(BIO_F_MEM_WRITE, BIO_R_WRITE_TO_READ_ONLY_BIO);
 216         goto end;
 217     }
 218     BIO_clear_retry_flags(b);
 219     blen = bbm->readp->length;
 220     mem_buf_sync(b);
 221     if (BUF_MEM_grow_clean(bbm->buf, blen + inl) == 0)
 222         goto end;
 223     memcpy(bbm->buf->data + blen, in, inl);
 224     *bbm->readp = *bbm->buf;
 225     ret = inl;
 226  end:
 227     return ret;
 228 }
 229
 230 static long mem_ctrl(BIO *b, int cmd, long num, void *ptr)
 231 {
 232     long ret = 1;
 233     char **pptr;
 234     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)b->ptr;
 235     BUF_MEM *bm;
 236
 237     switch (cmd) {
 238     case BIO_CTRL_RESET:
 239         bm = bbm->buf;
 240         if (bm->data != NULL) {
 241             /* For read only case reset to the start again */
 242             if ((b->flags & BIO_FLAGS_MEM_RDONLY) || (b->flags & BIO_FLAGS_NONCLEAR_RST)) {
 243                 bm->length = bm->max;
 244             } else {
 245                 memset(bm->data, 0, bm->max);
 246                 bm->length = 0;
 247             }
 248             *bbm->readp = *bbm->buf;
 249         }
 250         break;
 251     case BIO_CTRL_EOF:
 252         bm = bbm->readp;
 253         ret = (long)(bm->length == 0);
 254         break;
 255     case BIO_C_SET_BUF_MEM_EOF_RETURN:
 256         b->num = (int)num;
 257         break;
 258     case BIO_CTRL_INFO:
 259         bm = bbm->readp;
 260         ret = (long)bm->length;
 261         if (ptr != NULL) {
 262             pptr = (char **)ptr;
 263             *pptr = (char *)&(bm->data[0]);
 264         }
 265         break;
 266     case BIO_C_SET_BUF_MEM:
 267         mem_buf_free(b, 0);
 268         b->shutdown = (int)num;
 269         bbm->buf = ptr;
 270         *bbm->readp = *bbm->buf;
 271         b->ptr = bbm;
 272         break;
 273     case BIO_C_GET_BUF_MEM_PTR:
 274         if (ptr != NULL) {
 275             mem_buf_sync(b);
 276             bm = bbm->readp;
 277             pptr = (char **)ptr;
 278             *pptr = (char *)bm;
 279         }
 280         break;
 281     case BIO_CTRL_GET_CLOSE:
 282         ret = (long)b->shutdown;
 283         break;
 284     case BIO_CTRL_SET_CLOSE:
 285         b->shutdown = (int)num;
 286         break;
 287     case BIO_CTRL_WPENDING:
 288         ret = 0L;
 289         break;
 290     case BIO_CTRL_PENDING:
 291         bm = bbm->readp;
 292         ret = (long)bm->length;
 293         break;
 294     case BIO_CTRL_DUP:
 295     case BIO_CTRL_FLUSH:
 296         ret = 1;
 297         break;
 298     case BIO_CTRL_PUSH:
 299     case BIO_CTRL_POP:
 300     default:
 301         ret = 0;
 302         break;
 303     }
 304     return ret;
 305 }
 306
 307 static int mem_gets(BIO *bp, char *buf, int size)
 308 {
 309     int i, j;
 310     int ret = -1;
 311     char *p;
 312     BIO_BUF_MEM *bbm = (BIO_BUF_MEM *)bp->ptr;
 313     BUF_MEM *bm = bbm->readp;
 314
 315     BIO_clear_retry_flags(bp);
 316     j = bm->length;
 317     if ((size - 1) < j)
 318         j = size - 1;
 319     if (j <= 0) {
 320         *buf = '\0';
 321         return 0;
 322     }
 323     p = bm->data;
 324     for (i = 0; i < j; i++) {
 325         if (p[i] == '\n') {
 326             i++;
 327             break;
 328         }
 329     }
 330
 331     /*
 332      * i is now the max num of bytes to copy, either j or up to
 333      * and including the first newline
 334      */
 335
 336     i = mem_read(bp, buf, i);
 337     if (i > 0)
 338         buf[i] = '\0';
 339     ret = i;
 340     return ret;
 341 }
 342
 343 static int mem_puts(BIO *bp, const char *str)
 344 {
 345     int n, ret;
 346
 347     n = strlen(str);
 348     ret = mem_write(bp, str, n);
 349     /* memory semantics is that it will always work */
 350     return ret;
 351 }