/* crypto/evp/bio_enc.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.] */ #include #include #include "cryptlib.h" #include #include static int enc_write(BIO *h, const char *buf, int num); static int enc_read(BIO *h, char *buf, int size); /*static int enc_puts(BIO *h, const char *str); */ /*static int enc_gets(BIO *h, char *str, int size); */ static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2); static int enc_new(BIO *h); static int enc_free(BIO *data); static long enc_callback_ctrl(BIO *h, int cmd, bio_info_cb *fps); #define ENC_BLOCK_SIZE (1024*4) #define BUF_OFFSET (EVP_MAX_BLOCK_LENGTH*2) typedef struct enc_struct { int buf_len; int buf_off; int cont; /* <= 0 when finished */ int finished; int ok; /* bad decrypt */ EVP_CIPHER_CTX cipher; /* buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate * can return up to a block more data than is presented to it */ char buf[ENC_BLOCK_SIZE+BUF_OFFSET+2]; } BIO_ENC_CTX; static BIO_METHOD methods_enc= { BIO_TYPE_CIPHER,"cipher", enc_write, enc_read, NULL, /* enc_puts, */ NULL, /* enc_gets, */ enc_ctrl, enc_new, enc_free, enc_callback_ctrl, }; BIO_METHOD *BIO_f_cipher(void) { return(&methods_enc); } static int enc_new(BIO *bi) { BIO_ENC_CTX *ctx; ctx=(BIO_ENC_CTX *)OPENSSL_malloc(sizeof(BIO_ENC_CTX)); if (ctx == NULL) return(0); EVP_CIPHER_CTX_init(&ctx->cipher); ctx->buf_len=0; ctx->buf_off=0; ctx->cont=1; ctx->finished=0; ctx->ok=1; bi->init=0; bi->ptr=(char *)ctx; bi->flags=0; return(1); } static int enc_free(BIO *a) { BIO_ENC_CTX *b; if (a == NULL) return(0); b=(BIO_ENC_CTX *)a->ptr; EVP_CIPHER_CTX_cleanup(&(b->cipher)); OPENSSL_cleanse(a->ptr,sizeof(BIO_ENC_CTX)); OPENSSL_free(a->ptr); a->ptr=NULL; a->init=0; a->flags=0; return(1); } static int enc_read(BIO *b, char *out, int outl) { int ret=0,i; BIO_ENC_CTX *ctx; if (out == NULL) return(0); ctx=(BIO_ENC_CTX *)b->ptr; if ((ctx == NULL) || (b->next_bio == NULL)) return(0); /* First check if there are bytes decoded/encoded */ if (ctx->buf_len > 0) { 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; if (ctx->buf_len == ctx->buf_off) { ctx->buf_len=0; ctx->buf_off=0; } } /* At this point, we have room of outl bytes and an empty * buffer, so we should read in some more. */ while (outl > 0) { if (ctx->cont <= 0) break; /* read in at IV offset, read the EVP_Cipher * documentation about why */ i=BIO_read(b->next_bio,&(ctx->buf[BUF_OFFSET]),ENC_BLOCK_SIZE); if (i <= 0) { /* Should be continue next time we are called? */ if (!BIO_should_retry(b->next_bio)) { ctx->cont=i; i=EVP_CipherFinal_ex(&(ctx->cipher), (unsigned char *)ctx->buf, &(ctx->buf_len)); ctx->ok=i; ctx->buf_off=0; } else { ret=(ret == 0)?i:ret; break; } } else { EVP_CipherUpdate(&(ctx->cipher), (unsigned char *)ctx->buf,&ctx->buf_len, (unsigned char *)&(ctx->buf[BUF_OFFSET]),i); ctx->cont=1; /* Note: it is possible for EVP_CipherUpdate to * decrypt zero bytes because this is or looks like * the final block: if this happens we should retry * and either read more data or decrypt the final * block */ if(ctx->buf_len == 0) continue; } if (ctx->buf_len <= outl) i=ctx->buf_len; else i=outl; if (i <= 0) break; memcpy(out,ctx->buf,i); ret+=i; ctx->buf_off=i; outl-=i; out+=i; } BIO_clear_retry_flags(b); BIO_copy_next_retry(b); return((ret == 0)?ctx->cont:ret); } static int enc_write(BIO *b, const char *in, int inl) { int ret=0,n,i; BIO_ENC_CTX *ctx; ctx=(BIO_ENC_CTX *)b->ptr; ret=inl; BIO_clear_retry_flags(b); n=ctx->buf_len-ctx->buf_off; while (n > 0) { i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n); if (i <= 0) { BIO_copy_next_retry(b); return(i); } ctx->buf_off+=i; n-=i; } /* at this point all pending data has been written */ if ((in == NULL) || (inl <= 0)) return(0); ctx->buf_off=0; while (inl > 0) { n=(inl > ENC_BLOCK_SIZE)?ENC_BLOCK_SIZE:inl; EVP_CipherUpdate(&(ctx->cipher), (unsigned char *)ctx->buf,&ctx->buf_len, (unsigned char *)in,n); inl-=n; in+=n; ctx->buf_off=0; n=ctx->buf_len; while (n > 0) { i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n); if (i <= 0) { BIO_copy_next_retry(b); return (ret == inl) ? i : ret - inl; } n-=i; ctx->buf_off+=i; } ctx->buf_len=0; ctx->buf_off=0; } BIO_copy_next_retry(b); return(ret); } static long enc_ctrl(BIO *b, int cmd, long num, void *ptr) { BIO *dbio; BIO_ENC_CTX *ctx,*dctx; long ret=1; int i; EVP_CIPHER_CTX **c_ctx; ctx=(BIO_ENC_CTX *)b->ptr; switch (cmd) { case BIO_CTRL_RESET: ctx->ok=1; ctx->finished=0; EVP_CipherInit_ex(&(ctx->cipher),NULL,NULL,NULL,NULL, ctx->cipher.encrypt); 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_WPENDING: ret=ctx->buf_len-ctx->buf_off; if (ret <= 0) ret=BIO_ctrl(b->next_bio,cmd,num,ptr); break; case BIO_CTRL_PENDING: /* More to read in buffer */ ret=ctx->buf_len-ctx->buf_off; if (ret <= 0) ret=BIO_ctrl(b->next_bio,cmd,num,ptr); break; case BIO_CTRL_FLUSH: /* do a final write */ again: while (ctx->buf_len != ctx->buf_off) { i=enc_write(b,NULL,0); if (i < 0) return i; } if (!ctx->finished) { ctx->finished=1; ctx->buf_off=0; ret=EVP_CipherFinal_ex(&(ctx->cipher), (unsigned char *)ctx->buf, &(ctx->buf_len)); ctx->ok=(int)ret; if (ret <= 0) break; /* push out the bytes */ goto again; } /* Finally flush the underlying BIO */ ret=BIO_ctrl(b->next_bio,cmd,num,ptr); break; case BIO_C_GET_CIPHER_STATUS: ret=(long)ctx->ok; 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_C_GET_CIPHER_CTX: c_ctx=(EVP_CIPHER_CTX **)ptr; (*c_ctx)= &(ctx->cipher); b->init=1; break; case BIO_CTRL_DUP: dbio=(BIO *)ptr; dctx=(BIO_ENC_CTX *)dbio->ptr; memcpy(&(dctx->cipher),&(ctx->cipher),sizeof(ctx->cipher)); dbio->init=1; break; default: ret=BIO_ctrl(b->next_bio,cmd,num,ptr); break; } return(ret); } static long enc_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); } /* void BIO_set_cipher_ctx(b,c) BIO *b; EVP_CIPHER_ctx *c; { if (b == NULL) return; if ((b->callback != NULL) && (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0)) return; b->init=1; ctx=(BIO_ENC_CTX *)b->ptr; memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX)); if (b->callback != NULL) b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L); } */ void BIO_set_cipher(BIO *b, const EVP_CIPHER *c, unsigned char *k, unsigned char *i, int e) { BIO_ENC_CTX *ctx; if (b == NULL) return; if ((b->callback != NULL) && (b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,0L) <= 0)) return; b->init=1; ctx=(BIO_ENC_CTX *)b->ptr; EVP_CipherInit_ex(&(ctx->cipher),c,NULL, k,i,e); if (b->callback != NULL) b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,1L); }