crypto/evp/bio_enc.c - third_party/openssl - Git at Google

 /*
  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 #define OPENSSL_SUPPRESS_DEPRECATED /* for BIO_get_callback */

 #include <stdio.h>
 #include <errno.h>
 #include "internal/cryptlib.h"
 #include <openssl/buffer.h>
 #include <openssl/evp.h>
 #include "internal/bio.h"

 static int enc_write(BIO *h, const char *buf, int num);
 static int enc_read(BIO *h, char *buf, int size);
 static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2);
 static int enc_new(BIO *h);
 static int enc_free(BIO *data);
 static long enc_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fps);
 #define ENC_BLOCK_SIZE  (1024*4)
 #define ENC_MIN_CHUNK   (256)
 #define BUF_OFFSET      (ENC_MIN_CHUNK + EVP_MAX_BLOCK_LENGTH)

 typedef struct enc_struct {
     int buf_len;
     int buf_off;
     int cont;                   /* <= 0 when finished */
     int finished;
     int ok;                     /* bad decrypt */
     EVP_CIPHER_CTX *cipher;
     unsigned char *read_start, *read_end;
     /*
      * buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate can return
      * up to a block more data than is presented to it
      */
     unsigned char buf[BUF_OFFSET + ENC_BLOCK_SIZE];
 } BIO_ENC_CTX;

 static const BIO_METHOD methods_enc = {
     BIO_TYPE_CIPHER,
     "cipher",
     bwrite_conv,
     enc_write,
     bread_conv,
     enc_read,
     NULL,                       /* enc_puts, */
     NULL,                       /* enc_gets, */
     enc_ctrl,
     enc_new,
     enc_free,
     enc_callback_ctrl,
 };

 const BIO_METHOD *BIO_f_cipher(void)
 {
     return &methods_enc;
 }

 static int enc_new(BIO *bi)
 {
     BIO_ENC_CTX *ctx;

     if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL) {
         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
         return 0;
     }

     ctx->cipher = EVP_CIPHER_CTX_new();
     if (ctx->cipher == NULL) {
         OPENSSL_free(ctx);
         return 0;
     }
     ctx->cont = 1;
     ctx->ok = 1;
     ctx->read_end = ctx->read_start = &(ctx->buf[BUF_OFFSET]);
     BIO_set_data(bi, ctx);
     BIO_set_init(bi, 1);

     return 1;
 }

 static int enc_free(BIO *a)
 {
     BIO_ENC_CTX *b;

     if (a == NULL)
         return 0;

     b = BIO_get_data(a);
     if (b == NULL)
         return 0;

     EVP_CIPHER_CTX_free(b->cipher);
     OPENSSL_clear_free(b, sizeof(BIO_ENC_CTX));
     BIO_set_data(a, NULL);
     BIO_set_init(a, 0);

     return 1;
 }

 static int enc_read(BIO *b, char *out, int outl)
 {
     int ret = 0, i, blocksize;
     BIO_ENC_CTX *ctx;
     BIO *next;

     if (out == NULL)
         return 0;
     ctx = BIO_get_data(b);

     next = BIO_next(b);
     if ((ctx == NULL) || (next == NULL))
         return 0;

     /* First check if there are bytes decoded/encoded */
     if (ctx->buf_len > 0) {
         i = ctx->buf_len - ctx->buf_off;
         if (i > outl)
             i = outl;
         memcpy(out, &(ctx->buf[ctx->buf_off]), i);
         ret = i;
         out += i;
         outl -= i;
         ctx->buf_off += i;
         if (ctx->buf_len == ctx->buf_off) {
             ctx->buf_len = 0;
             ctx->buf_off = 0;
         }
     }

     blocksize = EVP_CIPHER_CTX_get_block_size(ctx->cipher);
     if (blocksize == 1)
         blocksize = 0;

     /*
      * At this point, we have room of outl bytes and an empty buffer, so we
      * should read in some more.
      */

     while (outl > 0) {
         if (ctx->cont <= 0)
             break;

         if (ctx->read_start == ctx->read_end) { /* time to read more data */
             ctx->read_end = ctx->read_start = &(ctx->buf[BUF_OFFSET]);
             i = BIO_read(next, ctx->read_start, ENC_BLOCK_SIZE);
             if (i > 0)
                 ctx->read_end += i;
         } else {
             i = ctx->read_end - ctx->read_start;
         }

         if (i <= 0) {
             /* Should be continue next time we are called? */
             if (!BIO_should_retry(next)) {
                 ctx->cont = i;
                 i = EVP_CipherFinal_ex(ctx->cipher,
                                        ctx->buf, &(ctx->buf_len));
                 ctx->ok = i;
                 ctx->buf_off = 0;
             } else {
                 ret = (ret == 0) ? i : ret;
                 break;
             }
         } else {
             if (outl > ENC_MIN_CHUNK) {
                 /*
                  * Depending on flags block cipher decrypt can write
                  * one extra block and then back off, i.e. output buffer
                  * has to accommodate extra block...
                  */
                 int j = outl - blocksize, buf_len;

                 if (!EVP_CipherUpdate(ctx->cipher,
                                       (unsigned char *)out, &buf_len,
                                       ctx->read_start, i > j ? j : i)) {
                     BIO_clear_retry_flags(b);
                     return 0;
                 }
                 ret += buf_len;
                 out += buf_len;
                 outl -= buf_len;

                 if ((i -= j) <= 0) {
                     ctx->read_start = ctx->read_end;
                     continue;
                 }
                 ctx->read_start += j;
             }
             if (i > ENC_MIN_CHUNK)
                 i = ENC_MIN_CHUNK;
             if (!EVP_CipherUpdate(ctx->cipher,
                                   ctx->buf, &ctx->buf_len,
                                   ctx->read_start, i)) {
                 BIO_clear_retry_flags(b);
                 ctx->ok = 0;
                 return 0;
             }
             ctx->read_start += i;
             ctx->cont = 1;
             /*
              * Note: it is possible for EVP_CipherUpdate to decrypt zero
              * bytes because this is or looks like the final block: if this
              * happens we should retry and either read more data or decrypt
              * the final block
              */
             if (ctx->buf_len == 0)
                 continue;
         }

         if (ctx->buf_len <= outl)
             i = ctx->buf_len;
         else
             i = outl;
         if (i <= 0)
             break;
         memcpy(out, ctx->buf, i);
         ret += i;
         ctx->buf_off = i;
         outl -= i;
         out += i;
     }

     BIO_clear_retry_flags(b);
     BIO_copy_next_retry(b);
     return ((ret == 0) ? ctx->cont : ret);
 }

 static int enc_write(BIO *b, const char *in, int inl)
 {
     int ret = 0, n, i;
     BIO_ENC_CTX *ctx;
     BIO *next;

     ctx = BIO_get_data(b);
     next = BIO_next(b);
     if ((ctx == NULL) || (next == NULL))
         return 0;

     ret = inl;

     BIO_clear_retry_flags(b);
     n = ctx->buf_len - ctx->buf_off;
     while (n > 0) {
         i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
         if (i <= 0) {
             BIO_copy_next_retry(b);
             return i;
         }
         ctx->buf_off += i;
         n -= i;
     }
     /* at this point all pending data has been written */

     if ((in == NULL) || (inl <= 0))
         return 0;

     ctx->buf_off = 0;
     while (inl > 0) {
         n = (inl > ENC_BLOCK_SIZE) ? ENC_BLOCK_SIZE : inl;
         if (!EVP_CipherUpdate(ctx->cipher,
                               ctx->buf, &ctx->buf_len,
                               (const unsigned char *)in, n)) {
             BIO_clear_retry_flags(b);
             ctx->ok = 0;
             return 0;
         }
         inl -= n;
         in += n;

         ctx->buf_off = 0;
         n = ctx->buf_len;
         while (n > 0) {
             i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
             if (i <= 0) {
                 BIO_copy_next_retry(b);
                 return (ret == inl) ? i : ret - inl;
             }
             n -= i;
             ctx->buf_off += i;
         }
         ctx->buf_len = 0;
         ctx->buf_off = 0;
     }
     BIO_copy_next_retry(b);
     return ret;
 }

 static long enc_ctrl(BIO *b, int cmd, long num, void *ptr)
 {
     BIO *dbio;
     BIO_ENC_CTX *ctx, *dctx;
     long ret = 1;
     int i;
     EVP_CIPHER_CTX **c_ctx;
     BIO *next;

     ctx = BIO_get_data(b);
     next = BIO_next(b);
     if (ctx == NULL)
         return 0;

     switch (cmd) {
     case BIO_CTRL_RESET:
         ctx->ok = 1;
         ctx->finished = 0;
         if (!EVP_CipherInit_ex(ctx->cipher, NULL, NULL, NULL, NULL,
                                EVP_CIPHER_CTX_is_encrypting(ctx->cipher)))
             return 0;
         ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_CTRL_EOF:         /* More to read */
         if (ctx->cont <= 0)
             ret = 1;
         else
             ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_CTRL_WPENDING:
         ret = ctx->buf_len - ctx->buf_off;
         if (ret <= 0)
             ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_CTRL_PENDING:     /* More to read in buffer */
         ret = ctx->buf_len - ctx->buf_off;
         if (ret <= 0)
             ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_CTRL_FLUSH:
         /* do a final write */
  again:
         while (ctx->buf_len != ctx->buf_off) {
             i = enc_write(b, NULL, 0);
             if (i < 0)
                 return i;
         }

         if (!ctx->finished) {
             ctx->finished = 1;
             ctx->buf_off = 0;
             ret = EVP_CipherFinal_ex(ctx->cipher,
                                      (unsigned char *)ctx->buf,
                                      &(ctx->buf_len));
             ctx->ok = (int)ret;
             if (ret <= 0)
                 break;

             /* push out the bytes */
             goto again;
         }

         /* Finally flush the underlying BIO */
         ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_C_GET_CIPHER_STATUS:
         ret = (long)ctx->ok;
         break;
     case BIO_C_DO_STATE_MACHINE:
         BIO_clear_retry_flags(b);
         ret = BIO_ctrl(next, cmd, num, ptr);
         BIO_copy_next_retry(b);
         break;
     case BIO_C_GET_CIPHER_CTX:
         c_ctx = (EVP_CIPHER_CTX **)ptr;
         *c_ctx = ctx->cipher;
         BIO_set_init(b, 1);
         break;
     case BIO_CTRL_DUP:
         dbio = (BIO *)ptr;
         dctx = BIO_get_data(dbio);
         dctx->cipher = EVP_CIPHER_CTX_new();
         if (dctx->cipher == NULL)
             return 0;
         ret = EVP_CIPHER_CTX_copy(dctx->cipher, ctx->cipher);
         if (ret)
             BIO_set_init(dbio, 1);
         break;
     default:
         ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     }
     return ret;
 }

 static long enc_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
 {
     BIO *next = BIO_next(b);

     if (next == NULL)
         return 0;

     return BIO_callback_ctrl(next, cmd, fp);
 }

 int BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k,
                    const unsigned char *i, int e)
 {
     BIO_ENC_CTX *ctx;
     BIO_callback_fn_ex callback_ex;
 #ifndef OPENSSL_NO_DEPRECATED_3_0
     long (*callback) (struct bio_st *, int, const char *, int, long, long) = NULL;
 #endif

     ctx = BIO_get_data(b);
     if (ctx == NULL)
         return 0;

     if ((callback_ex = BIO_get_callback_ex(b)) != NULL) {
         if (callback_ex(b, BIO_CB_CTRL, (const char *)c, 0, BIO_CTRL_SET,
                         e, 1, NULL) <= 0)
             return 0;
     }
 #ifndef OPENSSL_NO_DEPRECATED_3_0
     else {
         callback = BIO_get_callback(b);

         if ((callback != NULL) &&
             (callback(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e,
                       0L) <= 0))
             return 0;
     }
 #endif

     BIO_set_init(b, 1);

     if (!EVP_CipherInit_ex(ctx->cipher, c, NULL, k, i, e))
         return 0;

     if (callback_ex != NULL)
         return callback_ex(b, BIO_CB_CTRL | BIO_CB_RETURN, (const char *)c, 0,
                            BIO_CTRL_SET, e, 1, NULL);
 #ifndef OPENSSL_NO_DEPRECATED_3_0
     else if (callback != NULL)
         return callback(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e, 1L);
 #endif
     return 1;
 }
	/*
	* Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the Apache License 2.0 (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	#define OPENSSL_SUPPRESS_DEPRECATED /* for BIO_get_callback */

	#include <stdio.h>
	#include <errno.h>
	#include "internal/cryptlib.h"
	#include <openssl/buffer.h>
	#include <openssl/evp.h>
	#include "internal/bio.h"

	static int enc_write(BIO h, const char buf, int num);
	static int enc_read(BIO h, char buf, int size);
	static long enc_ctrl(BIO h, int cmd, long arg1, void arg2);
	static int enc_new(BIO *h);
	static int enc_free(BIO *data);
	static long enc_callback_ctrl(BIO h, int cmd, BIO_info_cb fps);
	#define ENC_BLOCK_SIZE (1024*4)
	#define ENC_MIN_CHUNK (256)
	#define BUF_OFFSET (ENC_MIN_CHUNK + EVP_MAX_BLOCK_LENGTH)

	typedef struct enc_struct {
	int buf_len;
	int buf_off;
	int cont; /* <= 0 when finished */
	int finished;
	int ok; /* bad decrypt */
	EVP_CIPHER_CTX *cipher;
	unsigned char read_start, read_end;
	/*
	* buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate can return
	* up to a block more data than is presented to it
	*/
	unsigned char buf[BUF_OFFSET + ENC_BLOCK_SIZE];
	} BIO_ENC_CTX;

	static const BIO_METHOD methods_enc = {
	BIO_TYPE_CIPHER,
	"cipher",
	bwrite_conv,
	enc_write,
	bread_conv,
	enc_read,
	NULL, /* enc_puts, */
	NULL, /* enc_gets, */
	enc_ctrl,
	enc_new,
	enc_free,
	enc_callback_ctrl,
	};

	const BIO_METHOD *BIO_f_cipher(void)
	{
	return &methods_enc;
	}

	static int enc_new(BIO *bi)
	{
	BIO_ENC_CTX *ctx;

	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL) {
	ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
	return 0;
	}

	ctx->cipher = EVP_CIPHER_CTX_new();
	if (ctx->cipher == NULL) {
	OPENSSL_free(ctx);
	return 0;
	}
	ctx->cont = 1;
	ctx->ok = 1;
	ctx->read_end = ctx->read_start = &(ctx->buf[BUF_OFFSET]);
	BIO_set_data(bi, ctx);
	BIO_set_init(bi, 1);

	return 1;
	}

	static int enc_free(BIO *a)
	{
	BIO_ENC_CTX *b;

	if (a == NULL)
	return 0;

	b = BIO_get_data(a);
	if (b == NULL)
	return 0;

	EVP_CIPHER_CTX_free(b->cipher);
	OPENSSL_clear_free(b, sizeof(BIO_ENC_CTX));
	BIO_set_data(a, NULL);
	BIO_set_init(a, 0);

	return 1;
	}

	static int enc_read(BIO b, char out, int outl)
	{
	int ret = 0, i, blocksize;
	BIO_ENC_CTX *ctx;
	BIO *next;

	if (out == NULL)
	return 0;
	ctx = BIO_get_data(b);

	next = BIO_next(b);
	if ((ctx == NULL) \|\| (next == NULL))
	return 0;

	/* First check if there are bytes decoded/encoded */
	if (ctx->buf_len > 0) {
	i = ctx->buf_len - ctx->buf_off;
	if (i > outl)
	i = outl;
	memcpy(out, &(ctx->buf[ctx->buf_off]), i);
	ret = i;
	out += i;
	outl -= i;
	ctx->buf_off += i;
	if (ctx->buf_len == ctx->buf_off) {
	ctx->buf_len = 0;
	ctx->buf_off = 0;
	}
	}

	blocksize = EVP_CIPHER_CTX_get_block_size(ctx->cipher);
	if (blocksize == 1)
	blocksize = 0;

	/*
	* At this point, we have room of outl bytes and an empty buffer, so we
	* should read in some more.
	*/

	while (outl > 0) {
	if (ctx->cont <= 0)
	break;

	if (ctx->read_start == ctx->read_end) { /* time to read more data */
	ctx->read_end = ctx->read_start = &(ctx->buf[BUF_OFFSET]);
	i = BIO_read(next, ctx->read_start, ENC_BLOCK_SIZE);
	if (i > 0)
	ctx->read_end += i;
	} else {
	i = ctx->read_end - ctx->read_start;
	}

	if (i <= 0) {
	/* Should be continue next time we are called? */
	if (!BIO_should_retry(next)) {
	ctx->cont = i;
	i = EVP_CipherFinal_ex(ctx->cipher,
	ctx->buf, &(ctx->buf_len));
	ctx->ok = i;
	ctx->buf_off = 0;
	} else {
	ret = (ret == 0) ? i : ret;
	break;
	}
	} else {
	if (outl > ENC_MIN_CHUNK) {
	/*
	* Depending on flags block cipher decrypt can write
	* one extra block and then back off, i.e. output buffer
	* has to accommodate extra block...
	*/
	int j = outl - blocksize, buf_len;

	if (!EVP_CipherUpdate(ctx->cipher,
	(unsigned char *)out, &buf_len,
	ctx->read_start, i > j ? j : i)) {
	BIO_clear_retry_flags(b);
	return 0;
	}
	ret += buf_len;
	out += buf_len;
	outl -= buf_len;

	if ((i -= j) <= 0) {
	ctx->read_start = ctx->read_end;
	continue;
	}
	ctx->read_start += j;
	}
	if (i > ENC_MIN_CHUNK)
	i = ENC_MIN_CHUNK;
	if (!EVP_CipherUpdate(ctx->cipher,
	ctx->buf, &ctx->buf_len,
	ctx->read_start, i)) {
	BIO_clear_retry_flags(b);
	ctx->ok = 0;
	return 0;
	}
	ctx->read_start += i;
	ctx->cont = 1;
	/*
	* Note: it is possible for EVP_CipherUpdate to decrypt zero
	* bytes because this is or looks like the final block: if this
	* happens we should retry and either read more data or decrypt
	* the final block
	*/
	if (ctx->buf_len == 0)
	continue;
	}

	if (ctx->buf_len <= outl)
	i = ctx->buf_len;
	else
	i = outl;
	if (i <= 0)
	break;
	memcpy(out, ctx->buf, i);
	ret += i;
	ctx->buf_off = i;
	outl -= i;
	out += i;
	}

	BIO_clear_retry_flags(b);
	BIO_copy_next_retry(b);
	return ((ret == 0) ? ctx->cont : ret);
	}

	static int enc_write(BIO b, const char in, int inl)
	{
	int ret = 0, n, i;
	BIO_ENC_CTX *ctx;
	BIO *next;

	ctx = BIO_get_data(b);
	next = BIO_next(b);
	if ((ctx == NULL) \|\| (next == NULL))
	return 0;

	ret = inl;

	BIO_clear_retry_flags(b);
	n = ctx->buf_len - ctx->buf_off;
	while (n > 0) {
	i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
	if (i <= 0) {
	BIO_copy_next_retry(b);
	return i;
	}
	ctx->buf_off += i;
	n -= i;
	}
	/* at this point all pending data has been written */

	if ((in == NULL) \|\| (inl <= 0))
	return 0;

	ctx->buf_off = 0;
	while (inl > 0) {
	n = (inl > ENC_BLOCK_SIZE) ? ENC_BLOCK_SIZE : inl;
	if (!EVP_CipherUpdate(ctx->cipher,
	ctx->buf, &ctx->buf_len,
	(const unsigned char *)in, n)) {
	BIO_clear_retry_flags(b);
	ctx->ok = 0;
	return 0;
	}
	inl -= n;
	in += n;

	ctx->buf_off = 0;
	n = ctx->buf_len;
	while (n > 0) {
	i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
	if (i <= 0) {
	BIO_copy_next_retry(b);
	return (ret == inl) ? i : ret - inl;
	}
	n -= i;
	ctx->buf_off += i;
	}
	ctx->buf_len = 0;
	ctx->buf_off = 0;
	}
	BIO_copy_next_retry(b);
	return ret;
	}

	static long enc_ctrl(BIO b, int cmd, long num, void ptr)
	{
	BIO *dbio;
	BIO_ENC_CTX ctx, dctx;
	long ret = 1;
	int i;
	EVP_CIPHER_CTX **c_ctx;
	BIO *next;

	ctx = BIO_get_data(b);
	next = BIO_next(b);
	if (ctx == NULL)
	return 0;

	switch (cmd) {
	case BIO_CTRL_RESET:
	ctx->ok = 1;
	ctx->finished = 0;
	if (!EVP_CipherInit_ex(ctx->cipher, NULL, NULL, NULL, NULL,
	EVP_CIPHER_CTX_is_encrypting(ctx->cipher)))
	return 0;
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_CTRL_EOF: /* More to read */
	if (ctx->cont <= 0)
	ret = 1;
	else
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_CTRL_WPENDING:
	ret = ctx->buf_len - ctx->buf_off;
	if (ret <= 0)
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_CTRL_PENDING: /* More to read in buffer */
	ret = ctx->buf_len - ctx->buf_off;
	if (ret <= 0)
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_CTRL_FLUSH:
	/* do a final write */
	again:
	while (ctx->buf_len != ctx->buf_off) {
	i = enc_write(b, NULL, 0);
	if (i < 0)
	return i;
	}

	if (!ctx->finished) {
	ctx->finished = 1;
	ctx->buf_off = 0;
	ret = EVP_CipherFinal_ex(ctx->cipher,
	(unsigned char *)ctx->buf,
	&(ctx->buf_len));
	ctx->ok = (int)ret;
	if (ret <= 0)
	break;

	/* push out the bytes */
	goto again;
	}

	/* Finally flush the underlying BIO */
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_C_GET_CIPHER_STATUS:
	ret = (long)ctx->ok;
	break;
	case BIO_C_DO_STATE_MACHINE:
	BIO_clear_retry_flags(b);
	ret = BIO_ctrl(next, cmd, num, ptr);
	BIO_copy_next_retry(b);
	break;
	case BIO_C_GET_CIPHER_CTX:
	c_ctx = (EVP_CIPHER_CTX **)ptr;
	*c_ctx = ctx->cipher;
	BIO_set_init(b, 1);
	break;
	case BIO_CTRL_DUP:
	dbio = (BIO *)ptr;
	dctx = BIO_get_data(dbio);
	dctx->cipher = EVP_CIPHER_CTX_new();
	if (dctx->cipher == NULL)
	return 0;
	ret = EVP_CIPHER_CTX_copy(dctx->cipher, ctx->cipher);
	if (ret)
	BIO_set_init(dbio, 1);
	break;
	default:
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	}
	return ret;
	}

	static long enc_callback_ctrl(BIO b, int cmd, BIO_info_cb fp)
	{
	BIO *next = BIO_next(b);

	if (next == NULL)
	return 0;

	return BIO_callback_ctrl(next, cmd, fp);
	}

	int BIO_set_cipher(BIO b, const EVP_CIPHER c, const unsigned char *k,
	const unsigned char *i, int e)
	{
	BIO_ENC_CTX *ctx;
	BIO_callback_fn_ex callback_ex;
	#ifndef OPENSSL_NO_DEPRECATED_3_0
	long (callback) (struct bio_st , int, const char *, int, long, long) = NULL;
	#endif

	ctx = BIO_get_data(b);
	if (ctx == NULL)
	return 0;

	if ((callback_ex = BIO_get_callback_ex(b)) != NULL) {
	if (callback_ex(b, BIO_CB_CTRL, (const char *)c, 0, BIO_CTRL_SET,
	e, 1, NULL) <= 0)
	return 0;
	}
	#ifndef OPENSSL_NO_DEPRECATED_3_0
	else {
	callback = BIO_get_callback(b);

	if ((callback != NULL) &&
	(callback(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e,
	0L) <= 0))
	return 0;
	}
	#endif

	BIO_set_init(b, 1);

	if (!EVP_CipherInit_ex(ctx->cipher, c, NULL, k, i, e))
	return 0;

	if (callback_ex != NULL)
	return callback_ex(b, BIO_CB_CTRL \| BIO_CB_RETURN, (const char *)c, 0,
	BIO_CTRL_SET, e, 1, NULL);
	#ifndef OPENSSL_NO_DEPRECATED_3_0
	else if (callback != NULL)
	return callback(b, BIO_CB_CTRL, (const char *)c, BIO_CTRL_SET, e, 1L);
	#endif
	return 1;
	}