1 /* crypto/evp/bio_enc.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
62 #include <openssl/buffer.h>
63 #include <openssl/evp.h>
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)
76 typedef struct enc_struct
80 int cont; /* <= 0 when 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
87 char buf[ENC_BLOCK_SIZE+BUF_OFFSET+2];
90 static BIO_METHOD methods_enc=
92 BIO_TYPE_CIPHER,"cipher",
103 BIO_METHOD *BIO_f_cipher(void)
105 return(&methods_enc);
108 static int enc_new(BIO *bi)
112 ctx=(BIO_ENC_CTX *)OPENSSL_malloc(sizeof(BIO_ENC_CTX));
113 if (ctx == NULL) return(0);
114 EVP_CIPHER_CTX_init(&ctx->cipher);
128 static int enc_free(BIO *a)
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);
143 static int enc_read(BIO *b, char *out, int outl)
148 if (out == NULL) return(0);
149 ctx=(BIO_ENC_CTX *)b->ptr;
151 if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
153 /* First check if there are bytes decoded/encoded */
154 if (ctx->buf_len > 0)
156 i=ctx->buf_len-ctx->buf_off;
157 if (i > outl) i=outl;
158 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
163 if (ctx->buf_len == ctx->buf_off)
170 /* At this point, we have room of outl bytes and an empty
171 * buffer, so we should read in some more. */
175 if (ctx->cont <= 0) break;
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);
183 /* Should be continue next time we are called? */
184 if (!BIO_should_retry(b->next_bio))
187 i=EVP_CipherFinal_ex(&(ctx->cipher),
188 (unsigned char *)ctx->buf,
195 ret=(ret == 0)?i:ret;
201 EVP_CipherUpdate(&(ctx->cipher),
202 (unsigned char *)ctx->buf,&ctx->buf_len,
203 (unsigned char *)&(ctx->buf[BUF_OFFSET]),i);
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
211 if(ctx->buf_len == 0) continue;
214 if (ctx->buf_len <= outl)
219 memcpy(out,ctx->buf,i);
226 BIO_clear_retry_flags(b);
227 BIO_copy_next_retry(b);
228 return((ret == 0)?ctx->cont:ret);
231 static int enc_write(BIO *b, const char *in, int inl)
236 ctx=(BIO_ENC_CTX *)b->ptr;
239 BIO_clear_retry_flags(b);
240 n=ctx->buf_len-ctx->buf_off;
243 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
246 BIO_copy_next_retry(b);
252 /* at this point all pending data has been written */
254 if ((in == NULL) || (inl <= 0)) return(0);
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);
270 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
273 BIO_copy_next_retry(b);
274 return (ret == inl) ? i : ret - inl;
282 BIO_copy_next_retry(b);
286 static long enc_ctrl(BIO *b, int cmd, long num, void *ptr)
289 BIO_ENC_CTX *ctx,*dctx;
292 EVP_CIPHER_CTX **c_ctx;
294 ctx=(BIO_ENC_CTX *)b->ptr;
301 EVP_CipherInit_ex(&(ctx->cipher),NULL,NULL,NULL,NULL,
302 ctx->cipher.encrypt);
303 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
305 case BIO_CTRL_EOF: /* More to read */
309 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
311 case BIO_CTRL_WPENDING:
312 ret=ctx->buf_len-ctx->buf_off;
314 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
316 case BIO_CTRL_PENDING: /* More to read in buffer */
317 ret=ctx->buf_len-ctx->buf_off;
319 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
322 /* do a final write */
324 while (ctx->buf_len != ctx->buf_off)
326 i=enc_write(b,NULL,0);
335 ret=EVP_CipherFinal_ex(&(ctx->cipher),
336 (unsigned char *)ctx->buf,
341 /* push out the bytes */
345 /* Finally flush the underlying BIO */
346 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
348 case BIO_C_GET_CIPHER_STATUS:
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);
356 case BIO_C_GET_CIPHER_CTX:
357 c_ctx=(EVP_CIPHER_CTX **)ptr;
358 (*c_ctx)= &(ctx->cipher);
363 dctx=(BIO_ENC_CTX *)dbio->ptr;
364 EVP_CIPHER_CTX_init(&dctx->cipher);
365 ret = EVP_CIPHER_CTX_copy(&dctx->cipher,&ctx->cipher);
370 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
376 static long enc_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
380 if (b->next_bio == NULL) return(0);
384 ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
391 void BIO_set_cipher_ctx(b,c)
395 if (b == NULL) return;
397 if ((b->callback != NULL) &&
398 (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))
402 ctx=(BIO_ENC_CTX *)b->ptr;
403 memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX));
405 if (b->callback != NULL)
406 b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
410 void BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k,
411 const unsigned char *i, int e)
415 if (b == NULL) return;
417 if ((b->callback != NULL) &&
418 (b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,0L) <= 0))
422 ctx=(BIO_ENC_CTX *)b->ptr;
423 EVP_CipherInit_ex(&(ctx->cipher),c,NULL, k,i,e);
425 if (b->callback != NULL)
426 b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,1L);