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);
68 * static int enc_puts(BIO *h, const char *str);
71 * static int enc_gets(BIO *h, char *str, int size);
73 static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2);
74 static int enc_new(BIO *h);
75 static int enc_free(BIO *data);
76 static long enc_callback_ctrl(BIO *h, int cmd, bio_info_cb *fps);
77 #define ENC_BLOCK_SIZE (1024*4)
78 #define BUF_OFFSET (EVP_MAX_BLOCK_LENGTH*2)
80 typedef struct enc_struct {
83 int cont; /* <= 0 when finished */
85 int ok; /* bad decrypt */
86 EVP_CIPHER_CTX cipher;
88 * buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate can return
89 * up to a block more data than is presented to it
91 char buf[ENC_BLOCK_SIZE + BUF_OFFSET + 2];
94 static BIO_METHOD methods_enc = {
95 BIO_TYPE_CIPHER, "cipher",
106 BIO_METHOD *BIO_f_cipher(void)
108 return (&methods_enc);
111 static int enc_new(BIO *bi)
115 ctx = (BIO_ENC_CTX *)OPENSSL_malloc(sizeof(BIO_ENC_CTX));
118 EVP_CIPHER_CTX_init(&ctx->cipher);
127 bi->ptr = (char *)ctx;
132 static int enc_free(BIO *a)
138 b = (BIO_ENC_CTX *)a->ptr;
139 EVP_CIPHER_CTX_cleanup(&(b->cipher));
140 OPENSSL_cleanse(a->ptr, sizeof(BIO_ENC_CTX));
141 OPENSSL_free(a->ptr);
148 static int enc_read(BIO *b, char *out, int outl)
155 ctx = (BIO_ENC_CTX *)b->ptr;
157 if ((ctx == NULL) || (b->next_bio == NULL))
160 /* First check if there are bytes decoded/encoded */
161 if (ctx->buf_len > 0) {
162 i = ctx->buf_len - ctx->buf_off;
165 memcpy(out, &(ctx->buf[ctx->buf_off]), i);
170 if (ctx->buf_len == ctx->buf_off) {
177 * At this point, we have room of outl bytes and an empty buffer, so we
178 * should read in some more.
186 * read in at IV offset, read the EVP_Cipher documentation about why
188 i = BIO_read(b->next_bio, &(ctx->buf[BUF_OFFSET]), ENC_BLOCK_SIZE);
191 /* Should be continue next time we are called? */
192 if (!BIO_should_retry(b->next_bio)) {
194 i = EVP_CipherFinal_ex(&(ctx->cipher),
195 (unsigned char *)ctx->buf,
200 ret = (ret == 0) ? i : ret;
204 if (!EVP_CipherUpdate(&ctx->cipher,
205 (unsigned char *)ctx->buf, &ctx->buf_len,
206 (unsigned char *)&(ctx->buf[BUF_OFFSET]),
208 BIO_clear_retry_flags(b);
214 * Note: it is possible for EVP_CipherUpdate to decrypt zero
215 * bytes because this is or looks like the final block: if this
216 * happens we should retry and either read more data or decrypt
219 if (ctx->buf_len == 0)
223 if (ctx->buf_len <= outl)
229 memcpy(out, ctx->buf, i);
236 BIO_clear_retry_flags(b);
237 BIO_copy_next_retry(b);
238 return ((ret == 0) ? ctx->cont : ret);
241 static int enc_write(BIO *b, const char *in, int inl)
246 ctx = (BIO_ENC_CTX *)b->ptr;
249 BIO_clear_retry_flags(b);
250 n = ctx->buf_len - ctx->buf_off;
252 i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
254 BIO_copy_next_retry(b);
260 /* at this point all pending data has been written */
262 if ((in == NULL) || (inl <= 0))
267 n = (inl > ENC_BLOCK_SIZE) ? ENC_BLOCK_SIZE : inl;
268 if (!EVP_CipherUpdate(&ctx->cipher,
269 (unsigned char *)ctx->buf, &ctx->buf_len,
270 (unsigned char *)in, n)) {
271 BIO_clear_retry_flags(b);
281 i = BIO_write(b->next_bio, &(ctx->buf[ctx->buf_off]), n);
283 BIO_copy_next_retry(b);
284 return (ret == inl) ? i : ret - inl;
292 BIO_copy_next_retry(b);
296 static long enc_ctrl(BIO *b, int cmd, long num, void *ptr)
299 BIO_ENC_CTX *ctx, *dctx;
302 EVP_CIPHER_CTX **c_ctx;
304 ctx = (BIO_ENC_CTX *)b->ptr;
310 EVP_CipherInit_ex(&(ctx->cipher), NULL, NULL, NULL, NULL,
311 ctx->cipher.encrypt);
312 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
314 case BIO_CTRL_EOF: /* More to read */
318 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
320 case BIO_CTRL_WPENDING:
321 ret = ctx->buf_len - ctx->buf_off;
323 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
325 case BIO_CTRL_PENDING: /* More to read in buffer */
326 ret = ctx->buf_len - ctx->buf_off;
328 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
331 /* do a final write */
333 while (ctx->buf_len != ctx->buf_off) {
334 i = enc_write(b, NULL, 0);
339 if (!ctx->finished) {
342 ret = EVP_CipherFinal_ex(&(ctx->cipher),
343 (unsigned char *)ctx->buf,
349 /* push out the bytes */
353 /* Finally flush the underlying BIO */
354 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
356 case BIO_C_GET_CIPHER_STATUS:
359 case BIO_C_DO_STATE_MACHINE:
360 BIO_clear_retry_flags(b);
361 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
362 BIO_copy_next_retry(b);
364 case BIO_C_GET_CIPHER_CTX:
365 c_ctx = (EVP_CIPHER_CTX **)ptr;
366 (*c_ctx) = &(ctx->cipher);
371 dctx = (BIO_ENC_CTX *)dbio->ptr;
372 EVP_CIPHER_CTX_init(&dctx->cipher);
373 ret = EVP_CIPHER_CTX_copy(&dctx->cipher, &ctx->cipher);
378 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
384 static long enc_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
388 if (b->next_bio == NULL)
392 ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
399 void BIO_set_cipher_ctx(b,c)
403 if (b == NULL) return;
405 if ((b->callback != NULL) &&
406 (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))
410 ctx=(BIO_ENC_CTX *)b->ptr;
411 memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX));
413 if (b->callback != NULL)
414 b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
418 void BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k,
419 const unsigned char *i, int e)
426 if ((b->callback != NULL) &&
427 (b->callback(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e, 0L) <=
432 ctx = (BIO_ENC_CTX *)b->ptr;
433 EVP_CipherInit_ex(&(ctx->cipher), c, NULL, k, i, e);
435 if (b->callback != NULL)
436 b->callback(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e, 1L);