Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 1 | /* crypto/evp/bio_enc.c */ |
| 2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This package is an SSL implementation written |
| 6 | * by Eric Young (eay@cryptsoft.com). |
| 7 | * The implementation was written so as to conform with Netscapes SSL. |
| 8 | * |
| 9 | * This library is free for commercial and non-commercial use as long as |
| 10 | * the following conditions are aheared to. The following conditions |
| 11 | * apply to all code found in this distribution, be it the RC4, RSA, |
| 12 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| 13 | * included with this distribution is covered by the same copyright terms |
| 14 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| 15 | * |
| 16 | * Copyright remains Eric Young's, and as such any Copyright notices in |
| 17 | * the code are not to be removed. |
| 18 | * If this package is used in a product, Eric Young should be given attribution |
| 19 | * as the author of the parts of the library used. |
| 20 | * This can be in the form of a textual message at program startup or |
| 21 | * in documentation (online or textual) provided with the package. |
| 22 | * |
| 23 | * Redistribution and use in source and binary forms, with or without |
| 24 | * modification, are permitted provided that the following conditions |
| 25 | * are met: |
| 26 | * 1. Redistributions of source code must retain the copyright |
| 27 | * notice, this list of conditions and the following disclaimer. |
| 28 | * 2. Redistributions in binary form must reproduce the above copyright |
| 29 | * notice, this list of conditions and the following disclaimer in the |
| 30 | * documentation and/or other materials provided with the distribution. |
| 31 | * 3. All advertising materials mentioning features or use of this software |
| 32 | * must display the following acknowledgement: |
| 33 | * "This product includes cryptographic software written by |
| 34 | * Eric Young (eay@cryptsoft.com)" |
| 35 | * The word 'cryptographic' can be left out if the rouines from the library |
| 36 | * being used are not cryptographic related :-). |
| 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
| 38 | * the apps directory (application code) you must include an acknowledgement: |
| 39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| 40 | * |
| 41 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| 42 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 43 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 44 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 45 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 46 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 47 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 49 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 50 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 51 | * SUCH DAMAGE. |
| 52 | * |
| 53 | * The licence and distribution terms for any publically available version or |
| 54 | * derivative of this code cannot be changed. i.e. this code cannot simply be |
| 55 | * copied and put under another distribution licence |
| 56 | * [including the GNU Public Licence.] |
| 57 | */ |
| 58 | |
| 59 | #include <stdio.h> |
| 60 | #include <errno.h> |
| 61 | #include "cryptlib.h" |
| 62 | #include <openssl/buffer.h> |
| 63 | #include <openssl/evp.h> |
| 64 | |
| 65 | static int enc_write(BIO *h, const char *buf, int num); |
| 66 | static int enc_read(BIO *h, char *buf, int size); |
| 67 | /*static int enc_puts(BIO *h, const char *str); */ |
| 68 | /*static int enc_gets(BIO *h, char *str, int size); */ |
| 69 | static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2); |
| 70 | static int enc_new(BIO *h); |
| 71 | static int enc_free(BIO *data); |
| 72 | static long enc_callback_ctrl(BIO *h, int cmd, bio_info_cb *fps); |
| 73 | #define ENC_BLOCK_SIZE (1024*4) |
| 74 | #define BUF_OFFSET (EVP_MAX_BLOCK_LENGTH*2) |
| 75 | |
| 76 | typedef struct enc_struct |
| 77 | { |
| 78 | int buf_len; |
| 79 | int buf_off; |
| 80 | int cont; /* <= 0 when finished */ |
| 81 | int finished; |
| 82 | int ok; /* bad decrypt */ |
| 83 | EVP_CIPHER_CTX cipher; |
| 84 | /* buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate |
| 85 | * can return up to a block more data than is presented to it |
| 86 | */ |
| 87 | char buf[ENC_BLOCK_SIZE+BUF_OFFSET+2]; |
| 88 | } BIO_ENC_CTX; |
| 89 | |
| 90 | static BIO_METHOD methods_enc= |
| 91 | { |
| 92 | BIO_TYPE_CIPHER,"cipher", |
| 93 | enc_write, |
| 94 | enc_read, |
| 95 | NULL, /* enc_puts, */ |
| 96 | NULL, /* enc_gets, */ |
| 97 | enc_ctrl, |
| 98 | enc_new, |
| 99 | enc_free, |
| 100 | enc_callback_ctrl, |
| 101 | }; |
| 102 | |
| 103 | BIO_METHOD *BIO_f_cipher(void) |
| 104 | { |
| 105 | return(&methods_enc); |
| 106 | } |
| 107 | |
| 108 | static int enc_new(BIO *bi) |
| 109 | { |
| 110 | BIO_ENC_CTX *ctx; |
| 111 | |
| 112 | ctx=(BIO_ENC_CTX *)OPENSSL_malloc(sizeof(BIO_ENC_CTX)); |
| 113 | if (ctx == NULL) return(0); |
| 114 | EVP_CIPHER_CTX_init(&ctx->cipher); |
| 115 | |
| 116 | ctx->buf_len=0; |
| 117 | ctx->buf_off=0; |
| 118 | ctx->cont=1; |
| 119 | ctx->finished=0; |
| 120 | ctx->ok=1; |
| 121 | |
| 122 | bi->init=0; |
| 123 | bi->ptr=(char *)ctx; |
| 124 | bi->flags=0; |
| 125 | return(1); |
| 126 | } |
| 127 | |
| 128 | static int enc_free(BIO *a) |
| 129 | { |
| 130 | BIO_ENC_CTX *b; |
| 131 | |
| 132 | if (a == NULL) return(0); |
| 133 | b=(BIO_ENC_CTX *)a->ptr; |
| 134 | EVP_CIPHER_CTX_cleanup(&(b->cipher)); |
| 135 | OPENSSL_cleanse(a->ptr,sizeof(BIO_ENC_CTX)); |
| 136 | OPENSSL_free(a->ptr); |
| 137 | a->ptr=NULL; |
| 138 | a->init=0; |
| 139 | a->flags=0; |
| 140 | return(1); |
| 141 | } |
| 142 | |
| 143 | static int enc_read(BIO *b, char *out, int outl) |
| 144 | { |
| 145 | int ret=0,i; |
| 146 | BIO_ENC_CTX *ctx; |
| 147 | |
| 148 | if (out == NULL) return(0); |
| 149 | ctx=(BIO_ENC_CTX *)b->ptr; |
| 150 | |
| 151 | if ((ctx == NULL) || (b->next_bio == NULL)) return(0); |
| 152 | |
| 153 | /* First check if there are bytes decoded/encoded */ |
| 154 | if (ctx->buf_len > 0) |
| 155 | { |
| 156 | i=ctx->buf_len-ctx->buf_off; |
| 157 | if (i > outl) i=outl; |
| 158 | memcpy(out,&(ctx->buf[ctx->buf_off]),i); |
| 159 | ret=i; |
| 160 | out+=i; |
| 161 | outl-=i; |
| 162 | ctx->buf_off+=i; |
| 163 | if (ctx->buf_len == ctx->buf_off) |
| 164 | { |
| 165 | ctx->buf_len=0; |
| 166 | ctx->buf_off=0; |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | /* At this point, we have room of outl bytes and an empty |
| 171 | * buffer, so we should read in some more. */ |
| 172 | |
| 173 | while (outl > 0) |
| 174 | { |
| 175 | if (ctx->cont <= 0) break; |
| 176 | |
| 177 | /* read in at IV offset, read the EVP_Cipher |
| 178 | * documentation about why */ |
| 179 | i=BIO_read(b->next_bio,&(ctx->buf[BUF_OFFSET]),ENC_BLOCK_SIZE); |
| 180 | |
| 181 | if (i <= 0) |
| 182 | { |
| 183 | /* Should be continue next time we are called? */ |
| 184 | if (!BIO_should_retry(b->next_bio)) |
| 185 | { |
| 186 | ctx->cont=i; |
| 187 | i=EVP_CipherFinal_ex(&(ctx->cipher), |
| 188 | (unsigned char *)ctx->buf, |
| 189 | &(ctx->buf_len)); |
| 190 | ctx->ok=i; |
| 191 | ctx->buf_off=0; |
| 192 | } |
| 193 | else |
| 194 | { |
| 195 | ret=(ret == 0)?i:ret; |
| 196 | break; |
| 197 | } |
| 198 | } |
| 199 | else |
| 200 | { |
| 201 | EVP_CipherUpdate(&(ctx->cipher), |
| 202 | (unsigned char *)ctx->buf,&ctx->buf_len, |
| 203 | (unsigned char *)&(ctx->buf[BUF_OFFSET]),i); |
| 204 | ctx->cont=1; |
| 205 | /* Note: it is possible for EVP_CipherUpdate to |
| 206 | * decrypt zero bytes because this is or looks like |
| 207 | * the final block: if this happens we should retry |
| 208 | * and either read more data or decrypt the final |
| 209 | * block |
| 210 | */ |
| 211 | if(ctx->buf_len == 0) continue; |
| 212 | } |
| 213 | |
| 214 | if (ctx->buf_len <= outl) |
| 215 | i=ctx->buf_len; |
| 216 | else |
| 217 | i=outl; |
| 218 | if (i <= 0) break; |
| 219 | memcpy(out,ctx->buf,i); |
| 220 | ret+=i; |
| 221 | ctx->buf_off=i; |
| 222 | outl-=i; |
| 223 | out+=i; |
| 224 | } |
| 225 | |
| 226 | BIO_clear_retry_flags(b); |
| 227 | BIO_copy_next_retry(b); |
| 228 | return((ret == 0)?ctx->cont:ret); |
| 229 | } |
| 230 | |
| 231 | static int enc_write(BIO *b, const char *in, int inl) |
| 232 | { |
| 233 | int ret=0,n,i; |
| 234 | BIO_ENC_CTX *ctx; |
| 235 | |
| 236 | ctx=(BIO_ENC_CTX *)b->ptr; |
| 237 | ret=inl; |
| 238 | |
| 239 | BIO_clear_retry_flags(b); |
| 240 | n=ctx->buf_len-ctx->buf_off; |
| 241 | while (n > 0) |
| 242 | { |
| 243 | i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n); |
| 244 | if (i <= 0) |
| 245 | { |
| 246 | BIO_copy_next_retry(b); |
| 247 | return(i); |
| 248 | } |
| 249 | ctx->buf_off+=i; |
| 250 | n-=i; |
| 251 | } |
| 252 | /* at this point all pending data has been written */ |
| 253 | |
| 254 | if ((in == NULL) || (inl <= 0)) return(0); |
| 255 | |
| 256 | ctx->buf_off=0; |
| 257 | while (inl > 0) |
| 258 | { |
| 259 | n=(inl > ENC_BLOCK_SIZE)?ENC_BLOCK_SIZE:inl; |
| 260 | EVP_CipherUpdate(&(ctx->cipher), |
| 261 | (unsigned char *)ctx->buf,&ctx->buf_len, |
| 262 | (unsigned char *)in,n); |
| 263 | inl-=n; |
| 264 | in+=n; |
| 265 | |
| 266 | ctx->buf_off=0; |
| 267 | n=ctx->buf_len; |
| 268 | while (n > 0) |
| 269 | { |
| 270 | i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n); |
| 271 | if (i <= 0) |
| 272 | { |
| 273 | BIO_copy_next_retry(b); |
| 274 | return (ret == inl) ? i : ret - inl; |
| 275 | } |
| 276 | n-=i; |
| 277 | ctx->buf_off+=i; |
| 278 | } |
| 279 | ctx->buf_len=0; |
| 280 | ctx->buf_off=0; |
| 281 | } |
| 282 | BIO_copy_next_retry(b); |
| 283 | return(ret); |
| 284 | } |
| 285 | |
| 286 | static long enc_ctrl(BIO *b, int cmd, long num, void *ptr) |
| 287 | { |
| 288 | BIO *dbio; |
| 289 | BIO_ENC_CTX *ctx,*dctx; |
| 290 | long ret=1; |
| 291 | int i; |
| 292 | EVP_CIPHER_CTX **c_ctx; |
| 293 | |
| 294 | ctx=(BIO_ENC_CTX *)b->ptr; |
| 295 | |
| 296 | switch (cmd) |
| 297 | { |
| 298 | case BIO_CTRL_RESET: |
| 299 | ctx->ok=1; |
| 300 | ctx->finished=0; |
| 301 | EVP_CipherInit_ex(&(ctx->cipher),NULL,NULL,NULL,NULL, |
| 302 | ctx->cipher.encrypt); |
| 303 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); |
| 304 | break; |
| 305 | case BIO_CTRL_EOF: /* More to read */ |
| 306 | if (ctx->cont <= 0) |
| 307 | ret=1; |
| 308 | else |
| 309 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); |
| 310 | break; |
| 311 | case BIO_CTRL_WPENDING: |
| 312 | ret=ctx->buf_len-ctx->buf_off; |
| 313 | if (ret <= 0) |
| 314 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); |
| 315 | break; |
| 316 | case BIO_CTRL_PENDING: /* More to read in buffer */ |
| 317 | ret=ctx->buf_len-ctx->buf_off; |
| 318 | if (ret <= 0) |
| 319 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); |
| 320 | break; |
| 321 | case BIO_CTRL_FLUSH: |
| 322 | /* do a final write */ |
| 323 | again: |
| 324 | while (ctx->buf_len != ctx->buf_off) |
| 325 | { |
| 326 | i=enc_write(b,NULL,0); |
| 327 | if (i < 0) |
| 328 | return i; |
| 329 | } |
| 330 | |
| 331 | if (!ctx->finished) |
| 332 | { |
| 333 | ctx->finished=1; |
| 334 | ctx->buf_off=0; |
| 335 | ret=EVP_CipherFinal_ex(&(ctx->cipher), |
| 336 | (unsigned char *)ctx->buf, |
| 337 | &(ctx->buf_len)); |
| 338 | ctx->ok=(int)ret; |
| 339 | if (ret <= 0) break; |
| 340 | |
| 341 | /* push out the bytes */ |
| 342 | goto again; |
| 343 | } |
| 344 | |
| 345 | /* Finally flush the underlying BIO */ |
| 346 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); |
| 347 | break; |
| 348 | case BIO_C_GET_CIPHER_STATUS: |
| 349 | ret=(long)ctx->ok; |
| 350 | break; |
| 351 | case BIO_C_DO_STATE_MACHINE: |
| 352 | BIO_clear_retry_flags(b); |
| 353 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); |
| 354 | BIO_copy_next_retry(b); |
| 355 | break; |
| 356 | case BIO_C_GET_CIPHER_CTX: |
| 357 | c_ctx=(EVP_CIPHER_CTX **)ptr; |
| 358 | (*c_ctx)= &(ctx->cipher); |
| 359 | b->init=1; |
| 360 | break; |
| 361 | case BIO_CTRL_DUP: |
| 362 | dbio=(BIO *)ptr; |
| 363 | dctx=(BIO_ENC_CTX *)dbio->ptr; |
| 364 | EVP_CIPHER_CTX_init(&dctx->cipher); |
| 365 | ret = EVP_CIPHER_CTX_copy(&dctx->cipher,&ctx->cipher); |
| 366 | if (ret) |
| 367 | dbio->init=1; |
| 368 | break; |
| 369 | default: |
| 370 | ret=BIO_ctrl(b->next_bio,cmd,num,ptr); |
| 371 | break; |
| 372 | } |
| 373 | return(ret); |
| 374 | } |
| 375 | |
| 376 | static long enc_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp) |
| 377 | { |
| 378 | long ret=1; |
| 379 | |
| 380 | if (b->next_bio == NULL) return(0); |
| 381 | switch (cmd) |
| 382 | { |
| 383 | default: |
| 384 | ret=BIO_callback_ctrl(b->next_bio,cmd,fp); |
| 385 | break; |
| 386 | } |
| 387 | return(ret); |
| 388 | } |
| 389 | |
| 390 | /* |
| 391 | void BIO_set_cipher_ctx(b,c) |
| 392 | BIO *b; |
| 393 | EVP_CIPHER_ctx *c; |
| 394 | { |
| 395 | if (b == NULL) return; |
| 396 | |
| 397 | if ((b->callback != NULL) && |
| 398 | (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0)) |
| 399 | return; |
| 400 | |
| 401 | b->init=1; |
| 402 | ctx=(BIO_ENC_CTX *)b->ptr; |
| 403 | memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX)); |
| 404 | |
| 405 | if (b->callback != NULL) |
| 406 | b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L); |
| 407 | } |
| 408 | */ |
| 409 | |
| 410 | void BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k, |
| 411 | const unsigned char *i, int e) |
| 412 | { |
| 413 | BIO_ENC_CTX *ctx; |
| 414 | |
| 415 | if (b == NULL) return; |
| 416 | |
| 417 | if ((b->callback != NULL) && |
| 418 | (b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,0L) <= 0)) |
| 419 | return; |
| 420 | |
| 421 | b->init=1; |
| 422 | ctx=(BIO_ENC_CTX *)b->ptr; |
| 423 | EVP_CipherInit_ex(&(ctx->cipher),c,NULL, k,i,e); |
| 424 | |
| 425 | if (b->callback != NULL) |
| 426 | b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,1L); |
| 427 | } |
| 428 | |