bss_mem.c

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/* crypto/bio/bss_mem.c */
/* Copyright (C) 1995-1998 Eric Young ([email protected])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([email protected]).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson ([email protected]).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young ([email protected])"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson ([email protected])"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include <errno.h>
#include "cryptlib.h"
#include <openssl/bio.h>

static int mem_write(BIO *h, const char *buf, int num);
static int mem_read(BIO *h, char *buf, int size);
static int mem_puts(BIO *h, const char *str);
static int mem_gets(BIO *h, char *str, int size);
static long mem_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int mem_new(BIO *h);
static int mem_free(BIO *data);
static BIO_METHOD mem_method=
    {
    BIO_TYPE_MEM,
    "memory buffer",
    mem_write,
    mem_read,
    mem_puts,
    mem_gets,
    mem_ctrl,
    mem_new,
    mem_free,
    NULL,
    };

/* bio->num is used to hold the value to return on 'empty', if it is
 * 0, should_retry is not set */

BIO_METHOD *BIO_s_mem(void)
    {
    return(&mem_method);
    }

BIO *BIO_new_mem_buf(void *buf, int len)
{
    BIO *ret;
    BUF_MEM *b;
    size_t sz;

    if (!buf) {
        BIOerr(BIO_F_BIO_NEW_MEM_BUF,BIO_R_NULL_PARAMETER);
        return NULL;
    }
    sz = (len<0) ? strlen(buf) : (size_t)len;
    if(!(ret = BIO_new(BIO_s_mem())) ) return NULL;
    b = (BUF_MEM *)ret->ptr;
    b->data = buf;
    b->length = sz;
    b->max = sz;
    ret->flags |= BIO_FLAGS_MEM_RDONLY;
    /* Since this is static data retrying wont help */
    ret->num = 0;
    return ret;
}

static int mem_new(BIO *bi)
    {
    BUF_MEM *b;

    if ((b=BUF_MEM_new()) == NULL)
        return(0);
    bi->shutdown=1;
    bi->init=1;
    bi->num= -1;
    bi->ptr=(char *)b;
    return(1);
    }

static int mem_free(BIO *a)
    {
    if (a == NULL) return(0);
    if (a->shutdown)
        {
        if ((a->init) && (a->ptr != NULL))
            {
            BUF_MEM *b;
            b = (BUF_MEM *)a->ptr;
            if(a->flags & BIO_FLAGS_MEM_RDONLY) b->data = NULL;
            BUF_MEM_free(b);
            a->ptr=NULL;
            }
        }
    return(1);
    }
    
static int mem_read(BIO *b, char *out, int outl)
    {
    int ret= -1;
    BUF_MEM *bm;

    bm=(BUF_MEM *)b->ptr;
    BIO_clear_retry_flags(b);
    ret=(outl >=0 && (size_t)outl > bm->length)?(int)bm->length:outl;
    if ((out != NULL) && (ret > 0)) {
        memcpy(out,bm->data,ret);
        bm->length-=ret;
        if(b->flags & BIO_FLAGS_MEM_RDONLY) bm->data += ret;
        else {
            memmove(&(bm->data[0]),&(bm->data[ret]),bm->length);
        }
    } else if (bm->length == 0)
        {
        ret = b->num;
        if (ret != 0)
            BIO_set_retry_read(b);
        }
    return(ret);
    }

static int mem_write(BIO *b, const char *in, int inl)
    {
    int ret= -1;
    int blen;
    BUF_MEM *bm;

    bm=(BUF_MEM *)b->ptr;
    if (in == NULL)
        {
        BIOerr(BIO_F_MEM_WRITE,BIO_R_NULL_PARAMETER);
        goto end;
        }

    if(b->flags & BIO_FLAGS_MEM_RDONLY) {
        BIOerr(BIO_F_MEM_WRITE,BIO_R_WRITE_TO_READ_ONLY_BIO);
        goto end;
    }

    BIO_clear_retry_flags(b);
    blen=bm->length;
    if (BUF_MEM_grow_clean(bm,blen+inl) != (blen+inl))
        goto end;
    memcpy(&(bm->data[blen]),in,inl);
    ret=inl;
end:
    return(ret);
    }

static long mem_ctrl(BIO *b, int cmd, long num, void *ptr)
    {
    long ret=1;
    char **pptr;

    BUF_MEM *bm=(BUF_MEM *)b->ptr;

    switch (cmd)
        {
    case BIO_CTRL_RESET:
        if (bm->data != NULL)
            {
            /* For read only case reset to the start again */
            if(b->flags & BIO_FLAGS_MEM_RDONLY) 
                {
                bm->data -= bm->max - bm->length;
                bm->length = bm->max;
                }
            else
                {
                memset(bm->data,0,bm->max);
                bm->length=0;
                }
            }
        break;
    case BIO_CTRL_EOF:
        ret=(long)(bm->length == 0);
        break;
    case BIO_C_SET_BUF_MEM_EOF_RETURN:
        b->num=(int)num;
        break;
    case BIO_CTRL_INFO:
        ret=(long)bm->length;
        if (ptr != NULL)
            {
            pptr=(char **)ptr;
            *pptr=(char *)&(bm->data[0]);
            }
        break;
    case BIO_C_SET_BUF_MEM:
        mem_free(b);
        b->shutdown=(int)num;
        b->ptr=ptr;
        break;
    case BIO_C_GET_BUF_MEM_PTR:
        if (ptr != NULL)
            {
            pptr=(char **)ptr;
            *pptr=(char *)bm;
            }
        break;
    case BIO_CTRL_GET_CLOSE:
        ret=(long)b->shutdown;
        break;
    case BIO_CTRL_SET_CLOSE:
        b->shutdown=(int)num;
        break;

    case BIO_CTRL_WPENDING:
        ret=0L;
        break;
    case BIO_CTRL_PENDING:
        ret=(long)bm->length;
        break;
    case BIO_CTRL_DUP:
    case BIO_CTRL_FLUSH:
        ret=1;
        break;
    case BIO_CTRL_PUSH:
    case BIO_CTRL_POP:
    default:
        ret=0;
        break;
        }
    return(ret);
    }

static int mem_gets(BIO *bp, char *buf, int size)
    {
    int i,j;
    int ret= -1;
    char *p;
    BUF_MEM *bm=(BUF_MEM *)bp->ptr;

    BIO_clear_retry_flags(bp);
    j=bm->length;
    if ((size-1) < j) j=size-1;
    if (j <= 0)
        {
        *buf='\0';
        return 0;
        }
    p=bm->data;
    for (i=0; i<j; i++)
        {
        if (p[i] == '\n')
            {
            i++;
            break;
            }
        }

    /*
     * i is now the max num of bytes to copy, either j or up to
     * and including the first newline
     */ 

    i=mem_read(bp,buf,i);
    if (i > 0) buf[i]='\0';
    ret=i;
    return(ret);
    }

static int mem_puts(BIO *bp, const char *str)
    {
    int n,ret;

    n=strlen(str);
    ret=mem_write(bp,str,n);
    /* memory semantics is that it will always work */
    return(ret);
    }