1 /* $OpenBSD: bio_enc.c,v 1.22 2018/08/24 19:30:24 tb Exp $ */
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.]
63 #include <openssl/buffer.h>
64 #include <openssl/evp.h>
66 static int enc_write(BIO *h, const char *buf, int num);
67 static int enc_read(BIO *h, char *buf, int size);
68 /*static int enc_puts(BIO *h, const char *str); */
69 /*static int enc_gets(BIO *h, char *str, int size); */
70 static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2);
71 static int enc_new(BIO *h);
72 static int enc_free(BIO *data);
73 static long enc_callback_ctrl(BIO *h, int cmd, bio_info_cb *fps);
74 #define ENC_BLOCK_SIZE (1024*4)
75 #define BUF_OFFSET (EVP_MAX_BLOCK_LENGTH*2)
77 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 const BIO_METHOD methods_enc = {
91 .type = BIO_TYPE_CIPHER,
98 .callback_ctrl = enc_callback_ctrl
104 return (&methods_enc);
112 ctx = malloc(sizeof(BIO_ENC_CTX));
115 EVP_CIPHER_CTX_init(&ctx->cipher);
124 bi->ptr = (char *)ctx;
136 b = (BIO_ENC_CTX *)a->ptr;
137 EVP_CIPHER_CTX_cleanup(&(b->cipher));
138 freezero(a->ptr, sizeof(BIO_ENC_CTX));
146 enc_read(BIO *b, char *out, int outl)
153 ctx = (BIO_ENC_CTX *)b->ptr;
155 if ((ctx == NULL) || (b->next_bio == NULL))
158 /* First check if there are bytes decoded/encoded */
159 if (ctx->buf_len > 0) {
160 i = ctx->buf_len - ctx->buf_off;
163 memcpy(out, &(ctx->buf[ctx->buf_off]), i);
168 if (ctx->buf_len == ctx->buf_off) {
174 /* At this point, we have room of outl bytes and an empty
175 * buffer, so we should read in some more. */
181 /* read in at IV offset, read the EVP_Cipher
182 * documentation about why */
183 i = BIO_read(b->next_bio, &(ctx->buf[BUF_OFFSET]), ENC_BLOCK_SIZE);
186 /* Should be continue next time we are called? */
187 if (!BIO_should_retry(b->next_bio)) {
189 i = EVP_CipherFinal_ex(&(ctx->cipher),
190 (unsigned char *)ctx->buf,
195 ret = (ret == 0) ? i : ret;
199 EVP_CipherUpdate(&(ctx->cipher),
200 (unsigned char *)ctx->buf, &ctx->buf_len,
201 (unsigned char *)&(ctx->buf[BUF_OFFSET]), i);
203 /* Note: it is possible for EVP_CipherUpdate to
204 * decrypt zero bytes because this is or looks like
205 * the final block: if this happens we should retry
206 * and either read more data or decrypt the final
209 if (ctx->buf_len == 0)
213 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);
232 enc_write(BIO *b, const char *in, int inl)
237 ctx = (BIO_ENC_CTX *)b->ptr;
240 BIO_clear_retry_flags(b);
241 n = ctx->buf_len - ctx->buf_off;
243 i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
245 BIO_copy_next_retry(b);
251 /* at this point all pending data has been written */
253 if ((in == NULL) || (inl <= 0))
258 n = (inl > ENC_BLOCK_SIZE) ? ENC_BLOCK_SIZE : inl;
259 EVP_CipherUpdate(&(ctx->cipher),
260 (unsigned char *)ctx->buf, &ctx->buf_len,
261 (unsigned char *)in, n);
268 i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
270 BIO_copy_next_retry(b);
271 return (ret == inl) ? i : ret - inl;
279 BIO_copy_next_retry(b);
284 enc_ctrl(BIO *b, int cmd, long num, void *ptr)
287 BIO_ENC_CTX *ctx, *dctx;
290 EVP_CIPHER_CTX **c_ctx;
292 ctx = (BIO_ENC_CTX *)b->ptr;
298 EVP_CipherInit_ex(&(ctx->cipher), NULL, NULL, NULL, NULL,
299 ctx->cipher.encrypt);
300 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
302 case BIO_CTRL_EOF: /* More to read */
306 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
308 case BIO_CTRL_WPENDING:
309 ret = ctx->buf_len - ctx->buf_off;
311 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
313 case BIO_CTRL_PENDING: /* More to read in buffer */
314 ret = ctx->buf_len - ctx->buf_off;
316 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
319 /* do a final write */
321 while (ctx->buf_len != ctx->buf_off) {
322 i = enc_write(b, NULL, 0);
327 if (!ctx->finished) {
330 ret = EVP_CipherFinal_ex(&(ctx->cipher),
331 (unsigned char *)ctx->buf,
337 /* push out the bytes */
341 /* Finally flush the underlying BIO */
342 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
344 case BIO_C_GET_CIPHER_STATUS:
347 case BIO_C_DO_STATE_MACHINE:
348 BIO_clear_retry_flags(b);
349 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
350 BIO_copy_next_retry(b);
352 case BIO_C_GET_CIPHER_CTX:
353 c_ctx = (EVP_CIPHER_CTX **)ptr;
354 (*c_ctx) = &(ctx->cipher);
359 dctx = (BIO_ENC_CTX *)dbio->ptr;
360 EVP_CIPHER_CTX_init(&dctx->cipher);
361 ret = EVP_CIPHER_CTX_copy(&dctx->cipher, &ctx->cipher);
366 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
373 enc_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
377 if (b->next_bio == NULL)
381 ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
388 void BIO_set_cipher_ctx(b,c)
392 if (b == NULL) return;
394 if ((b->callback != NULL) &&
395 (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))
399 ctx=(BIO_ENC_CTX *)b->ptr;
400 memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX));
402 if (b->callback != NULL)
403 b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
408 BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k,
409 const unsigned char *i, int e)
412 long (*cb)(BIO *, int, const char *, int, long, long);
417 if ((ctx = BIO_get_data(b)) == NULL)
420 if ((cb = BIO_get_callback(b)) != NULL) {
421 if (cb(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e, 0L)
428 if (!EVP_CipherInit_ex(&(ctx->cipher), c, NULL, k, i, e))
432 return cb(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e, 1L);