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| -rw-r--r-- | crypto/evp/bio_ok.c | 576 |
1 files changed, 576 insertions, 0 deletions
diff --git a/crypto/evp/bio_ok.c b/crypto/evp/bio_ok.c new file mode 100644 index 0000000000..8d7ffe28a1 --- /dev/null +++ b/crypto/evp/bio_ok.c @@ -0,0 +1,576 @@ +/* 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; + } + } + |