bf_buff.c

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/* crypto/bio/bf_buff.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 buffer_write(BIO *h, const char *buf,int num);
static int buffer_read(BIO *h, char *buf, int size);
static int buffer_puts(BIO *h, const char *str);
static int buffer_gets(BIO *h, char *str, int size);
static long buffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
static int buffer_new(BIO *h);
static int buffer_free(BIO *data);
static long buffer_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
#define DEFAULT_BUFFER_SIZE 4096

static BIO_METHOD methods_buffer=
    {
    BIO_TYPE_BUFFER,
    "buffer",
    buffer_write,
    buffer_read,
    buffer_puts,
    buffer_gets,
    buffer_ctrl,
    buffer_new,
    buffer_free,
    buffer_callback_ctrl,
    };

BIO_METHOD *BIO_f_buffer(void)
    {
    return(&methods_buffer);
    }

static int buffer_new(BIO *bi)
    {
    BIO_F_BUFFER_CTX *ctx;

    ctx=(BIO_F_BUFFER_CTX *)OPENSSL_malloc(sizeof(BIO_F_BUFFER_CTX));
    if (ctx == NULL) return(0);
    ctx->ibuf=(char *)OPENSSL_malloc(DEFAULT_BUFFER_SIZE);
    if (ctx->ibuf == NULL) { OPENSSL_free(ctx); return(0); }
    ctx->obuf=(char *)OPENSSL_malloc(DEFAULT_BUFFER_SIZE);
    if (ctx->obuf == NULL) { OPENSSL_free(ctx->ibuf); OPENSSL_free(ctx); return(0); }
    ctx->ibuf_size=DEFAULT_BUFFER_SIZE;
    ctx->obuf_size=DEFAULT_BUFFER_SIZE;
    ctx->ibuf_len=0;
    ctx->ibuf_off=0;
    ctx->obuf_len=0;
    ctx->obuf_off=0;

    bi->init=1;
    bi->ptr=(char *)ctx;
    bi->flags=0;
    return(1);
    }

static int buffer_free(BIO *a)
    {
    BIO_F_BUFFER_CTX *b;

    if (a == NULL) return(0);
    b=(BIO_F_BUFFER_CTX *)a->ptr;
    if (b->ibuf != NULL) OPENSSL_free(b->ibuf);
    if (b->obuf != NULL) OPENSSL_free(b->obuf);
    OPENSSL_free(a->ptr);
    a->ptr=NULL;
    a->init=0;
    a->flags=0;
    return(1);
    }
    
static int buffer_read(BIO *b, char *out, int outl)
    {
    int i,num=0;
    BIO_F_BUFFER_CTX *ctx;

    if (out == NULL) return(0);
    ctx=(BIO_F_BUFFER_CTX *)b->ptr;

    if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
    num=0;
    BIO_clear_retry_flags(b);

start:
    i=ctx->ibuf_len;
    /* If there is stuff left over, grab it */
    if (i != 0)
        {
        if (i > outl) i=outl;
        memcpy(out,&(ctx->ibuf[ctx->ibuf_off]),i);
        ctx->ibuf_off+=i;
        ctx->ibuf_len-=i;
        num+=i;
        if (outl == i)  return(num);
        outl-=i;
        out+=i;
        }

    /* We may have done a partial read. try to do more.
     * We have nothing in the buffer.
     * If we get an error and have read some data, just return it
     * and let them retry to get the error again.
     * copy direct to parent address space */
    if (outl > ctx->ibuf_size)
        {
        for (;;)
            {
            i=BIO_read(b->next_bio,out,outl);
            if (i <= 0)
                {
                BIO_copy_next_retry(b);
                if (i < 0) return((num > 0)?num:i);
                if (i == 0) return(num);
                }
            num+=i;
            if (outl == i) return(num);
            out+=i;
            outl-=i;
            }
        }
    /* else */

    /* we are going to be doing some buffering */
    i=BIO_read(b->next_bio,ctx->ibuf,ctx->ibuf_size);
    if (i <= 0)
        {
        BIO_copy_next_retry(b);
        if (i < 0) return((num > 0)?num:i);
        if (i == 0) return(num);
        }
    ctx->ibuf_off=0;
    ctx->ibuf_len=i;

    /* Lets re-read using ourselves :-) */
    goto start;
    }

static int buffer_write(BIO *b, const char *in, int inl)
    {
    int i,num=0;
    BIO_F_BUFFER_CTX *ctx;

    if ((in == NULL) || (inl <= 0)) return(0);
    ctx=(BIO_F_BUFFER_CTX *)b->ptr;
    if ((ctx == NULL) || (b->next_bio == NULL)) return(0);

    BIO_clear_retry_flags(b);
start:
    i=ctx->obuf_size-(ctx->obuf_len+ctx->obuf_off);
    /* add to buffer and return */
    if (i >= inl)
        {
        memcpy(&(ctx->obuf[ctx->obuf_off+ctx->obuf_len]),in,inl);
        ctx->obuf_len+=inl;
        return(num+inl);
        }
    /* else */
    /* stuff already in buffer, so add to it first, then flush */
    if (ctx->obuf_len != 0)
        {
        if (i > 0) /* lets fill it up if we can */
            {
            memcpy(&(ctx->obuf[ctx->obuf_off+ctx->obuf_len]),in,i);
            in+=i;
            inl-=i;
            num+=i;
            ctx->obuf_len+=i;
            }
        /* we now have a full buffer needing flushing */
        for (;;)
            {
            i=BIO_write(b->next_bio,&(ctx->obuf[ctx->obuf_off]),
                ctx->obuf_len);
            if (i <= 0)
                {
                BIO_copy_next_retry(b);

                if (i < 0) return((num > 0)?num:i);
                if (i == 0) return(num);
                }
            ctx->obuf_off+=i;
            ctx->obuf_len-=i;
            if (ctx->obuf_len == 0) break;
            }
        }
    /* we only get here if the buffer has been flushed and we
     * still have stuff to write */
    ctx->obuf_off=0;

    /* we now have inl bytes to write */
    while (inl >= ctx->obuf_size)
        {
        i=BIO_write(b->next_bio,in,inl);
        if (i <= 0)
            {
            BIO_copy_next_retry(b);
            if (i < 0) return((num > 0)?num:i);
            if (i == 0) return(num);
            }
        num+=i;
        in+=i;
        inl-=i;
        if (inl == 0) return(num);
        }

    /* copy the rest into the buffer since we have only a small 
     * amount left */
    goto start;
    }

static long buffer_ctrl(BIO *b, int cmd, long num, void *ptr)
    {
    BIO *dbio;
    BIO_F_BUFFER_CTX *ctx;
    long ret=1;
    char *p1,*p2;
    int r,i,*ip;
    int ibs,obs;

    ctx=(BIO_F_BUFFER_CTX *)b->ptr;

    switch (cmd)
        {
    case BIO_CTRL_RESET:
        ctx->ibuf_off=0;
        ctx->ibuf_len=0;
        ctx->obuf_off=0;
        ctx->obuf_len=0;
        if (b->next_bio == NULL) return(0);
        ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
        break;
    case BIO_CTRL_INFO:
        ret=(long)ctx->obuf_len;
        break;
    case BIO_C_GET_BUFF_NUM_LINES:
        ret=0;
        p1=ctx->ibuf;
        for (i=0; i<ctx->ibuf_len; i++)
            {
            if (p1[ctx->ibuf_off + i] == '\n') ret++;
            }
        break;
    case BIO_CTRL_WPENDING:
        ret=(long)ctx->obuf_len;
        if (ret == 0)
            {
            if (b->next_bio == NULL) return(0);
            ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
            }
        break;
    case BIO_CTRL_PENDING:
        ret=(long)ctx->ibuf_len;
        if (ret == 0)
            {
            if (b->next_bio == NULL) return(0);
            ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
            }
        break;
    case BIO_C_SET_BUFF_READ_DATA:
        if (num > ctx->ibuf_size)
            {
            p1=OPENSSL_malloc((int)num);
            if (p1 == NULL) goto malloc_error;
            if (ctx->ibuf != NULL) OPENSSL_free(ctx->ibuf);
            ctx->ibuf=p1;
            }
        ctx->ibuf_off=0;
        ctx->ibuf_len=(int)num;
        memcpy(ctx->ibuf,ptr,(int)num);
        ret=1;
        break;
    case BIO_C_SET_BUFF_SIZE:
        if (ptr != NULL)
            {
            ip=(int *)ptr;
            if (*ip == 0)
                {
                ibs=(int)num;
                obs=ctx->obuf_size;
                }
            else /* if (*ip == 1) */
                {
                ibs=ctx->ibuf_size;
                obs=(int)num;
                }
            }
        else
            {
            ibs=(int)num;
            obs=(int)num;
            }
        p1=ctx->ibuf;
        p2=ctx->obuf;
        if ((ibs > DEFAULT_BUFFER_SIZE) && (ibs != ctx->ibuf_size))
            {
            p1=(char *)OPENSSL_malloc((int)num);
            if (p1 == NULL) goto malloc_error;
            }
        if ((obs > DEFAULT_BUFFER_SIZE) && (obs != ctx->obuf_size))
            {
            p2=(char *)OPENSSL_malloc((int)num);
            if (p2 == NULL)
                {
                if (p1 != ctx->ibuf) OPENSSL_free(p1);
                goto malloc_error;
                }
            }
        if (ctx->ibuf != p1)
            {
            OPENSSL_free(ctx->ibuf);
            ctx->ibuf=p1;
            ctx->ibuf_off=0;
            ctx->ibuf_len=0;
            ctx->ibuf_size=ibs;
            }
        if (ctx->obuf != p2)
            {
            OPENSSL_free(ctx->obuf);
            ctx->obuf=p2;
            ctx->obuf_off=0;
            ctx->obuf_len=0;
            ctx->obuf_size=obs;
            }
        break;
    case BIO_C_DO_STATE_MACHINE:
        if (b->next_bio == NULL) return(0);
        BIO_clear_retry_flags(b);
        ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
        BIO_copy_next_retry(b);
        break;

    case BIO_CTRL_FLUSH:
        if (b->next_bio == NULL) return(0);
        if (ctx->obuf_len <= 0)
            {
            ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
            break;
            }

        for (;;)
            {
            BIO_clear_retry_flags(b);
            if (ctx->obuf_len > 0)
                {
                r=BIO_write(b->next_bio,
                    &(ctx->obuf[ctx->obuf_off]),
                    ctx->obuf_len);
#if 0
fprintf(stderr,"FLUSH [%3d] %3d -> %3d\n",ctx->obuf_off,ctx->obuf_len,r);
#endif
                BIO_copy_next_retry(b);
                if (r <= 0) return((long)r);
                ctx->obuf_off+=r;
                ctx->obuf_len-=r;
                }
            else
                {
                ctx->obuf_len=0;
                ctx->obuf_off=0;
                ret=1;
                break;
                }
            }
        ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
        break;
    case BIO_CTRL_DUP:
        dbio=(BIO *)ptr;
        if (    !BIO_set_read_buffer_size(dbio,ctx->ibuf_size) ||
            !BIO_set_write_buffer_size(dbio,ctx->obuf_size))
            ret=0;
        break;
    default:
        if (b->next_bio == NULL) return(0);
        ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
        break;
        }
    return(ret);
malloc_error:
    BIOerr(BIO_F_BUFFER_CTRL,ERR_R_MALLOC_FAILURE);
    return(0);
    }

static long buffer_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
    {
    long ret=1;

    if (b->next_bio == NULL) return(0);
    switch (cmd)
        {
    default:
        ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
        break;
        }
    return(ret);
    }

static int buffer_gets(BIO *b, char *buf, int size)
    {
    BIO_F_BUFFER_CTX *ctx;
    int num=0,i,flag;
    char *p;

    ctx=(BIO_F_BUFFER_CTX *)b->ptr;
    size--; /* reserve space for a '\0' */
    BIO_clear_retry_flags(b);

    for (;;)
        {
        if (ctx->ibuf_len > 0)
            {
            p= &(ctx->ibuf[ctx->ibuf_off]);
            flag=0;
            for (i=0; (i<ctx->ibuf_len) && (i<size); i++)
                {
                *(buf++)=p[i];
                if (p[i] == '\n')
                    {
                    flag=1;
                    i++;
                    break;
                    }
                }
            num+=i;
            size-=i;
            ctx->ibuf_len-=i;
            ctx->ibuf_off+=i;
            if (flag || size == 0)
                {
                *buf='\0';
                return(num);
                }
            }
        else    /* read another chunk */
            {
            i=BIO_read(b->next_bio,ctx->ibuf,ctx->ibuf_size);
            if (i <= 0)
                {
                BIO_copy_next_retry(b);
                *buf='\0';
                if (i < 0) return((num > 0)?num:i);
                if (i == 0) return(num);
                }
            ctx->ibuf_len=i;
            ctx->ibuf_off=0;
            }
        }
    }

static int buffer_puts(BIO *b, const char *str)
    {
    return(buffer_write(b,str,strlen(str)));
    }