--- /dev/null
+/* crypto/evp/bio_ok.c */
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * 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 (tjh@cryptsoft.com).
+ *
+ * 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 (eay@cryptsoft.com)"
+ * 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 (tjh@cryptsoft.com)"
+ *
+ * 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.]
+ */
+
+/*
+ From: Arne Ansper <arne@cyber.ee>
+
+ Why BIO_f_reliable?
+
+ I wrote function which took BIO* as argument, read data from it
+ and processed it. Then I wanted to store the input file in
+ encrypted form. OK I pushed BIO_f_cipher to the BIO stack
+ and everything was OK. BUT if user types wrong password
+ BIO_f_cipher outputs only garbage and my function crashes. Yes
+ I can and I should fix my function, but BIO_f_cipher is
+ easy way to add encryption support to many exisiting applications
+ and it's hard to debug and fix them all.
+
+ So I wanted another BIO which would catch the incorrect passwords and
+ file damages which cause garbage on BIO_f_cipher's output.
+
+ The easy way is to push the BIO_f_md and save the checksum at
+ the end of the file. However there are several problems with this
+ approach:
+
+ 1) you must somehow separate checksum from actual data.
+ 2) you need lot's of memory when reading the file, because you
+ must read to the end of the file and verify the checksum before
+ leting the application to read the data.
+
+ BIO_f_reliable tries to solve both problems, so that you can
+ read and write arbitraly long streams using only fixed amount
+ of memory.
+
+ BIO_f_reliable splits data stream into blocks. Each block is prefixed
+ with it's length and suffixed with it's digest. So you need only
+ several Kbytes of memory to buffer single block before verifying
+ it's digest.
+
+ BIO_f_reliable goes futher and adds several important capabilities:
+
+ 1) the digest of the block is computed over the whole stream
+ -- so nobody can rearrange the blocks or remove or replace them.
+
+ 2) to detect invalid passwords right at the start BIO_f_reliable
+ adds special prefix to the stream. In order to avoid known plain-text
+ attacks this prefix is generated as follows:
+
+ *) digest is initialized with random seed instead of
+ standardized one.
+ *) same seed is written to ouput
+ *) well-known text is then hashed and the output
+ of the digest is also written to output.
+
+ reader can now read the seed from stream, hash the same string
+ and then compare the digest output.
+
+ Bad things: BIO_f_reliable knows what's going on in EVP_Digest. I
+ initialy wrote and tested this code on x86 machine and wrote the
+ digests out in machine-dependent order :( There are people using
+ this code and I cannot change this easily without making existing
+ data files unreadable.
+
+*/
+
+#include <stdio.h>
+#include <errno.h>
+#include "cryptlib.h"
+#include "buffer.h"
+#include "bio.h"
+#include "evp.h"
+#include "rand.h"
+
+#ifndef NOPROTO
+static int ok_write(BIO *h,char *buf,int num);
+static int ok_read(BIO *h,char *buf,int size);
+static long ok_ctrl(BIO *h,int cmd,long arg1,char *arg2);
+static int ok_new(BIO *h);
+static int ok_free(BIO *data);
+static void sig_out(BIO* b);
+static void sig_in(BIO* b);
+static void block_out(BIO* b);
+static void block_in(BIO* b);
+#else
+static int ok_write();
+static int ok_read();
+static long ok_ctrl();
+static int ok_new();
+static int ok_free();
+static void sig_out();
+static void sig_in();
+static void block_out();
+static void block_in();
+#endif
+
+#define OK_BLOCK_SIZE (1024*4)
+#define OK_BLOCK_BLOCK 4
+#define IOBS (OK_BLOCK_SIZE+ OK_BLOCK_BLOCK+ 3*EVP_MAX_MD_SIZE)
+#define WELLKNOWN "The quick brown fox jumped over the lazy dog's back."
+
+#ifndef L_ENDIAN
+#define swapem(x) \
+ ((unsigned long int)((((unsigned long int)(x) & 0x000000ffU) << 24) | \
+ (((unsigned long int)(x) & 0x0000ff00U) << 8) | \
+ (((unsigned long int)(x) & 0x00ff0000U) >> 8) | \
+ (((unsigned long int)(x) & 0xff000000U) >> 24)))
+#else
+#define swapem(x) (x)
+#endif
+
+typedef struct ok_struct
+ {
+ int buf_len;
+ int buf_off;
+ int buf_len_save;
+ int buf_off_save;
+ int cont; /* <= 0 when finished */
+ int finished;
+ EVP_MD_CTX md;
+ int blockout; /* output block is ready */
+ int sigio; /* must process signature */
+ char buf[IOBS];
+ } BIO_OK_CTX;
+
+static BIO_METHOD methods_ok=
+ {
+ BIO_TYPE_CIPHER,"reliable",
+ ok_write,
+ ok_read,
+ NULL, /* ok_puts, */
+ NULL, /* ok_gets, */
+ ok_ctrl,
+ ok_new,
+ ok_free,
+ };
+
+BIO_METHOD *BIO_f_reliable()
+ {
+ return(&methods_ok);
+ }
+
+static int ok_new(bi)
+BIO *bi;
+ {
+ BIO_OK_CTX *ctx;
+
+ ctx=(BIO_OK_CTX *)Malloc(sizeof(BIO_OK_CTX));
+ if (ctx == NULL) return(0);
+
+ ctx->buf_len=0;
+ ctx->buf_off=0;
+ ctx->buf_len_save=0;
+ ctx->buf_off_save=0;
+ ctx->cont=1;
+ ctx->finished=0;
+ ctx->blockout= 0;
+ ctx->sigio=1;
+
+ bi->init=0;
+ bi->ptr=(char *)ctx;
+ bi->flags=0;
+ return(1);
+ }
+
+static int ok_free(a)
+BIO *a;
+ {
+ if (a == NULL) return(0);
+ memset(a->ptr,0,sizeof(BIO_OK_CTX));
+ Free(a->ptr);
+ a->ptr=NULL;
+ a->init=0;
+ a->flags=0;
+ return(1);
+ }
+
+static int ok_read(b,out,outl)
+BIO *b;
+char *out;
+int outl;
+ {
+ int ret=0,i,n;
+ BIO_OK_CTX *ctx;
+
+ if (out == NULL) return(0);
+ ctx=(BIO_OK_CTX *)b->ptr;
+
+ if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) return(0);
+
+ while(outl > 0)
+ {
+
+ /* copy clean bytes to output buffer */
+ if (ctx->blockout)
+ {
+ i=ctx->buf_len-ctx->buf_off;
+ if (i > outl) i=outl;
+ memcpy(out,&(ctx->buf[ctx->buf_off]),i);
+ ret+=i;
+ out+=i;
+ outl-=i;
+ ctx->buf_off+=i;
+
+ /* all clean bytes are out */
+ if (ctx->buf_len == ctx->buf_off)
+ {
+ ctx->buf_off=0;
+
+ /* copy start of the next block into proper place */
+ if(ctx->buf_len_save- ctx->buf_off_save > 0)
+ {
+ ctx->buf_len= ctx->buf_len_save- ctx->buf_off_save;
+ memmove(ctx->buf, &(ctx->buf[ctx->buf_off_save]),
+ ctx->buf_len);
+ }
+ else
+ {
+ ctx->buf_len=0;
+ }
+ ctx->blockout= 0;
+ }
+ }
+
+ /* output buffer full -- cancel */
+ if (outl == 0) break;
+
+ /* no clean bytes in buffer -- fill it */
+ n=IOBS- ctx->buf_len;
+ i=BIO_read(b->next_bio,&(ctx->buf[ctx->buf_len]),n);
+
+ if (i <= 0) break; /* nothing new */
+
+ ctx->buf_len+= i;
+
+ /* no signature yet -- check if we got one */
+ if (ctx->sigio == 1) sig_in(b);
+
+ /* signature ok -- check if we got block */
+ if (ctx->sigio == 0) block_in(b);
+
+ /* invalid block -- cancel */
+ if (ctx->cont <= 0) break;
+
+ }
+
+ BIO_clear_retry_flags(b);
+ BIO_copy_next_retry(b);
+ return(ret);
+ }
+
+static int ok_write(b,in,inl)
+BIO *b;
+char *in;
+int inl;
+ {
+ int ret=0,n,i;
+ BIO_OK_CTX *ctx;
+
+ ctx=(BIO_OK_CTX *)b->ptr;
+ ret=inl;
+
+ if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) return(0);
+
+ if(ctx->sigio) sig_out(b);
+
+ do{
+ BIO_clear_retry_flags(b);
+ n=ctx->buf_len-ctx->buf_off;
+ while (ctx->blockout && n > 0)
+ {
+ i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
+ if (i <= 0)
+ {
+ BIO_copy_next_retry(b);
+ if(!BIO_should_retry(b))
+ ctx->cont= 0;
+ return(i);
+ }
+ ctx->buf_off+=i;
+ n-=i;
+ }
+
+ /* at this point all pending data has been written */
+ ctx->blockout= 0;
+ if (ctx->buf_len == ctx->buf_off)
+ {
+ ctx->buf_len=OK_BLOCK_BLOCK;
+ ctx->buf_off=0;
+ }
+
+ if ((in == NULL) || (inl <= 0)) return(0);
+
+ n= (inl+ ctx->buf_len > OK_BLOCK_SIZE+ OK_BLOCK_BLOCK) ?
+ OK_BLOCK_SIZE+ OK_BLOCK_BLOCK- ctx->buf_len : inl;
+
+ memcpy((unsigned char *)(&(ctx->buf[ctx->buf_len])),(unsigned char *)in,n);
+ ctx->buf_len+= n;
+ inl-=n;
+ in+=n;
+
+ if(ctx->buf_len >= OK_BLOCK_SIZE+ OK_BLOCK_BLOCK)
+ {
+ block_out(b);
+ }
+ }while(inl > 0);
+
+ BIO_clear_retry_flags(b);
+ BIO_copy_next_retry(b);
+ return(ret);
+ }
+
+static long ok_ctrl(b,cmd,num,ptr)
+BIO *b;
+int cmd;
+long num;
+char *ptr;
+ {
+ BIO_OK_CTX *ctx;
+ EVP_MD *md;
+ EVP_MD **ppmd;
+ long ret=1;
+ int i;
+
+ ctx=(BIO_OK_CTX *)b->ptr;
+
+ switch (cmd)
+ {
+ case BIO_CTRL_RESET:
+ ctx->buf_len=0;
+ ctx->buf_off=0;
+ ctx->buf_len_save=0;
+ ctx->buf_off_save=0;
+ ctx->cont=1;
+ ctx->finished=0;
+ ctx->blockout= 0;
+ ctx->sigio=1;
+ ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
+ break;
+ case BIO_CTRL_EOF: /* More to read */
+ if (ctx->cont <= 0)
+ ret=1;
+ else
+ ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
+ break;
+ case BIO_CTRL_PENDING: /* More to read in buffer */
+ case BIO_CTRL_WPENDING: /* More to read in buffer */
+ ret=ctx->blockout ? ctx->buf_len-ctx->buf_off : 0;
+ if (ret <= 0)
+ ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
+ break;
+ case BIO_CTRL_FLUSH:
+ /* do a final write */
+ if(ctx->blockout == 0)
+ block_out(b);
+
+ while (ctx->blockout)
+ {
+ i=ok_write(b,NULL,0);
+ if (i < 0)
+ {
+ ret=i;
+ break;
+ }
+ }
+
+ ctx->finished=1;
+ ctx->buf_off=ctx->buf_len=0;
+ ctx->cont=(int)ret;
+
+ /* Finally flush the underlying BIO */
+ ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
+ break;
+ case BIO_C_DO_STATE_MACHINE:
+ BIO_clear_retry_flags(b);
+ ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
+ BIO_copy_next_retry(b);
+ break;
+ case BIO_CTRL_INFO:
+ ret=(long)ctx->cont;
+ break;
+ case BIO_C_SET_MD:
+ md=(EVP_MD *)ptr;
+ EVP_DigestInit(&(ctx->md),md);
+ b->init=1;
+ break;
+ case BIO_C_GET_MD:
+ if (b->init)
+ {
+ ppmd=(EVP_MD **)ptr;
+ *ppmd=ctx->md.digest;
+ }
+ else
+ ret=0;
+ break;
+ default:
+ ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
+ break;
+ }
+ return(ret);
+ }
+
+static void longswap(char* ptr, int len)
+{
+#ifndef L_ENDIAN
+ int i;
+
+ for(i= 0;i < len;i+= 4){
+ *((unsigned long *)&(ptr[i]))= swapem(*((unsigned long *)&(ptr[i])));
+ }
+#endif
+}
+
+static void sig_out(BIO* b)
+ {
+ BIO_OK_CTX *ctx;
+ EVP_MD_CTX *md;
+
+ ctx=(BIO_OK_CTX *)b->ptr;
+ md= &(ctx->md);
+
+ if(ctx->buf_len+ 2* md->digest->md_size > OK_BLOCK_SIZE) return;
+
+ EVP_DigestInit(md, md->digest);
+ RAND_bytes(&(md->md.base[0]), md->digest->md_size);
+ memcpy(&(ctx->buf[ctx->buf_len]), &(md->md.base[0]), md->digest->md_size);
+ longswap(&(ctx->buf[ctx->buf_len]), md->digest->md_size);
+ ctx->buf_len+= md->digest->md_size;
+
+ EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN));
+ md->digest->final(&(ctx->buf[ctx->buf_len]), &(md->md.base[0]));
+ ctx->buf_len+= md->digest->md_size;
+ ctx->blockout= 1;
+ ctx->sigio= 0;
+ }
+
+static void sig_in(BIO* b)
+ {
+ BIO_OK_CTX *ctx;
+ EVP_MD_CTX *md;
+ unsigned char tmp[EVP_MAX_MD_SIZE];
+ int ret= 0;
+
+ ctx=(BIO_OK_CTX *)b->ptr;
+ md= &(ctx->md);
+
+ if(ctx->buf_len- ctx->buf_off < 2* md->digest->md_size) return;
+
+ EVP_DigestInit(md, md->digest);
+ memcpy(&(md->md.base[0]), &(ctx->buf[ctx->buf_off]), md->digest->md_size);
+ longswap(&(md->md.base[0]), md->digest->md_size);
+ ctx->buf_off+= md->digest->md_size;
+
+ EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN));
+ md->digest->final(tmp, &(md->md.base[0]));
+ ret= memcmp(&(ctx->buf[ctx->buf_off]), tmp, md->digest->md_size) == 0;
+ ctx->buf_off+= md->digest->md_size;
+ if(ret == 1)
+ {
+ ctx->sigio= 0;
+ if(ctx->buf_len != ctx->buf_off)
+ {
+ memmove(ctx->buf, &(ctx->buf[ctx->buf_off]), ctx->buf_len- ctx->buf_off);
+ }
+ ctx->buf_len-= ctx->buf_off;
+ ctx->buf_off= 0;
+ }
+ else
+ {
+ ctx->cont= 0;
+ }
+ }
+
+static void block_out(BIO* b)
+ {
+ BIO_OK_CTX *ctx;
+ EVP_MD_CTX *md;
+ unsigned long tl;
+
+ ctx=(BIO_OK_CTX *)b->ptr;
+ md= &(ctx->md);
+
+ tl= ctx->buf_len- OK_BLOCK_BLOCK;
+ tl= swapem(tl);
+ memcpy(ctx->buf, &tl, OK_BLOCK_BLOCK);
+ tl= swapem(tl);
+ EVP_DigestUpdate(md, &(ctx->buf[OK_BLOCK_BLOCK]), tl);
+ md->digest->final(&(ctx->buf[ctx->buf_len]), &(md->md.base[0]));
+ ctx->buf_len+= md->digest->md_size;
+ ctx->blockout= 1;
+ }
+
+static void block_in(BIO* b)
+ {
+ BIO_OK_CTX *ctx;
+ EVP_MD_CTX *md;
+ unsigned long tl= 0;
+ unsigned char tmp[EVP_MAX_MD_SIZE];
+
+ ctx=(BIO_OK_CTX *)b->ptr;
+ md= &(ctx->md);
+
+ memcpy(&tl, ctx->buf, OK_BLOCK_BLOCK);
+ tl= swapem(tl);
+ if (ctx->buf_len < tl+ OK_BLOCK_BLOCK+ md->digest->md_size) return;
+
+ EVP_DigestUpdate(md, &(ctx->buf[OK_BLOCK_BLOCK]), tl);
+ md->digest->final(tmp, &(md->md.base[0]));
+ if(memcmp(&(ctx->buf[tl+ OK_BLOCK_BLOCK]), tmp, md->digest->md_size) == 0)
+ {
+ /* there might be parts from next block lurking around ! */
+ ctx->buf_off_save= tl+ OK_BLOCK_BLOCK+ md->digest->md_size;
+ ctx->buf_len_save= ctx->buf_len;
+ ctx->buf_off= OK_BLOCK_BLOCK;
+ ctx->buf_len= tl+ OK_BLOCK_BLOCK;
+ ctx->blockout= 1;
+ }
+ else
+ {
+ ctx->cont= 0;
+ }
+ }
+
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