2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
12 #include "internal/cryptlib.h"
13 #include <openssl/buffer.h>
14 #include <openssl/evp.h>
15 #include "internal/bio.h"
17 static int enc_write(BIO *h, const char *buf, int num);
18 static int enc_read(BIO *h, char *buf, int size);
20 * static int enc_puts(BIO *h, const char *str);
23 * static int enc_gets(BIO *h, char *str, int size);
25 static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2);
26 static int enc_new(BIO *h);
27 static int enc_free(BIO *data);
28 static long enc_callback_ctrl(BIO *h, int cmd, bio_info_cb *fps);
29 #define ENC_BLOCK_SIZE (1024*4)
30 #define ENC_MIN_CHUNK (256)
31 #define BUF_OFFSET (ENC_MIN_CHUNK + EVP_MAX_BLOCK_LENGTH)
33 typedef struct enc_struct {
36 int cont; /* <= 0 when finished */
38 int ok; /* bad decrypt */
39 EVP_CIPHER_CTX *cipher;
40 unsigned char *read_start, *read_end;
42 * buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate can return
43 * up to a block more data than is presented to it
45 unsigned char buf[BUF_OFFSET + ENC_BLOCK_SIZE];
48 static const BIO_METHOD methods_enc = {
49 BIO_TYPE_CIPHER, "cipher",
50 /* TODO: Convert to new style write function */
53 /* TODO: Convert to new style read function */
64 const BIO_METHOD *BIO_f_cipher(void)
66 return (&methods_enc);
69 static int enc_new(BIO *bi)
73 ctx = OPENSSL_zalloc(sizeof(*ctx));
77 ctx->cipher = EVP_CIPHER_CTX_new();
78 if (ctx->cipher == NULL) {
84 ctx->read_end = ctx->read_start = &(ctx->buf[BUF_OFFSET]);
85 BIO_set_data(bi, ctx);
91 static int enc_free(BIO *a)
102 EVP_CIPHER_CTX_free(b->cipher);
103 OPENSSL_clear_free(b, sizeof(BIO_ENC_CTX));
104 BIO_set_data(a, NULL);
110 static int enc_read(BIO *b, char *out, int outl)
112 int ret = 0, i, blocksize;
118 ctx = BIO_get_data(b);
121 if ((ctx == NULL) || (next == NULL))
124 /* First check if there are bytes decoded/encoded */
125 if (ctx->buf_len > 0) {
126 i = ctx->buf_len - ctx->buf_off;
129 memcpy(out, &(ctx->buf[ctx->buf_off]), i);
134 if (ctx->buf_len == ctx->buf_off) {
140 blocksize = EVP_CIPHER_CTX_block_size(ctx->cipher);
145 * At this point, we have room of outl bytes and an empty buffer, so we
146 * should read in some more.
153 if (ctx->read_start == ctx->read_end) { /* time to read more data */
154 ctx->read_end = ctx->read_start = &(ctx->buf[BUF_OFFSET]);
155 i = BIO_read(next, ctx->read_start, ENC_BLOCK_SIZE);
159 i = ctx->read_end - ctx->read_start;
163 /* Should be continue next time we are called? */
164 if (!BIO_should_retry(next)) {
166 i = EVP_CipherFinal_ex(ctx->cipher,
167 ctx->buf, &(ctx->buf_len));
171 ret = (ret == 0) ? i : ret;
175 if (outl > ENC_MIN_CHUNK) {
177 * Depending on flags block cipher decrypt can write
178 * one extra block and then back off, i.e. output buffer
179 * has to accommodate extra block...
181 int j = outl - blocksize, buf_len;
183 if (!EVP_CipherUpdate(ctx->cipher,
184 (unsigned char *)out, &buf_len,
185 ctx->read_start, i > j ? j : i)) {
186 BIO_clear_retry_flags(b);
194 ctx->read_start = ctx->read_end;
197 ctx->read_start += j;
199 if (i > ENC_MIN_CHUNK)
201 if (!EVP_CipherUpdate(ctx->cipher,
202 ctx->buf, &ctx->buf_len,
203 ctx->read_start, i)) {
204 BIO_clear_retry_flags(b);
208 ctx->read_start += i;
211 * Note: it is possible for EVP_CipherUpdate to decrypt zero
212 * bytes because this is or looks like the final block: if this
213 * happens we should retry and either read more data or decrypt
216 if (ctx->buf_len == 0)
220 if (ctx->buf_len <= outl)
226 memcpy(out, ctx->buf, i);
233 BIO_clear_retry_flags(b);
234 BIO_copy_next_retry(b);
235 return ((ret == 0) ? ctx->cont : ret);
238 static int enc_write(BIO *b, const char *in, int inl)
244 ctx = BIO_get_data(b);
246 if ((ctx == NULL) || (next == NULL))
251 BIO_clear_retry_flags(b);
252 n = ctx->buf_len - ctx->buf_off;
254 i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
256 BIO_copy_next_retry(b);
262 /* at this point all pending data has been written */
264 if ((in == NULL) || (inl <= 0))
269 n = (inl > ENC_BLOCK_SIZE) ? ENC_BLOCK_SIZE : inl;
270 if (!EVP_CipherUpdate(ctx->cipher,
271 ctx->buf, &ctx->buf_len,
272 (const unsigned char *)in, n)) {
273 BIO_clear_retry_flags(b);
283 i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
285 BIO_copy_next_retry(b);
286 return (ret == inl) ? i : ret - inl;
294 BIO_copy_next_retry(b);
298 static long enc_ctrl(BIO *b, int cmd, long num, void *ptr)
301 BIO_ENC_CTX *ctx, *dctx;
304 EVP_CIPHER_CTX **c_ctx;
307 ctx = BIO_get_data(b);
316 if (!EVP_CipherInit_ex(ctx->cipher, NULL, NULL, NULL, NULL,
317 EVP_CIPHER_CTX_encrypting(ctx->cipher)))
319 ret = BIO_ctrl(next, cmd, num, ptr);
321 case BIO_CTRL_EOF: /* More to read */
325 ret = BIO_ctrl(next, cmd, num, ptr);
327 case BIO_CTRL_WPENDING:
328 ret = ctx->buf_len - ctx->buf_off;
330 ret = BIO_ctrl(next, cmd, num, ptr);
332 case BIO_CTRL_PENDING: /* More to read in buffer */
333 ret = ctx->buf_len - ctx->buf_off;
335 ret = BIO_ctrl(next, cmd, num, ptr);
338 /* do a final write */
340 while (ctx->buf_len != ctx->buf_off) {
341 i = enc_write(b, NULL, 0);
346 if (!ctx->finished) {
349 ret = EVP_CipherFinal_ex(ctx->cipher,
350 (unsigned char *)ctx->buf,
356 /* push out the bytes */
360 /* Finally flush the underlying BIO */
361 ret = BIO_ctrl(next, cmd, num, ptr);
363 case BIO_C_GET_CIPHER_STATUS:
366 case BIO_C_DO_STATE_MACHINE:
367 BIO_clear_retry_flags(b);
368 ret = BIO_ctrl(next, cmd, num, ptr);
369 BIO_copy_next_retry(b);
371 case BIO_C_GET_CIPHER_CTX:
372 c_ctx = (EVP_CIPHER_CTX **)ptr;
373 *c_ctx = ctx->cipher;
378 dctx = BIO_get_data(dbio);
379 dctx->cipher = EVP_CIPHER_CTX_new();
380 if (dctx->cipher == NULL)
382 ret = EVP_CIPHER_CTX_copy(dctx->cipher, ctx->cipher);
384 BIO_set_init(dbio, 1);
387 ret = BIO_ctrl(next, cmd, num, ptr);
393 static long enc_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
396 BIO *next = BIO_next(b);
402 ret = BIO_callback_ctrl(next, cmd, fp);
409 void BIO_set_cipher_ctx(b,c)
413 if (b == NULL) return;
415 if ((b->callback != NULL) &&
416 (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))
420 ctx=(BIO_ENC_CTX *)b->ptr;
421 memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX));
423 if (b->callback != NULL)
424 b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
428 int BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k,
429 const unsigned char *i, int e)
432 long (*callback) (struct bio_st *, int, const char *, int, long, long);
434 ctx = BIO_get_data(b);
438 callback = BIO_get_callback(b);
440 if ((callback != NULL) &&
441 (callback(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e,
447 if (!EVP_CipherInit_ex(ctx->cipher, c, NULL, k, i, e))
450 if (callback != NULL)
451 return callback(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e, 1L);