evp_key.c

mediastreamer2是开源的网络传输媒体流的库

/* crypto/evp/evp_key.c */
/* Copyright (C) 1995-1998 Eric Young ([e-mail])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([e-mail]).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson ([e-mail]).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young ([e-mail])"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson ([e-mail])"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include "cryptlib.h"
#include <openssl/x509.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/ui.h>

/* should be init to zeros. */
static char prompt_string[80];

void EVP_set_pw_prompt(const char *prompt)
	{
	if (prompt == NULL)
		prompt_string[0]='\0';
	else
		{
		strncpy(prompt_string,prompt,79);
		prompt_string[79]='\0';
		}
	}

char *EVP_get_pw_prompt(void)
	{
	if (prompt_string[0] == '\0')
		return(NULL);
	else
		return(prompt_string);
	}

/* For historical reasons, the standard function for reading passwords is
 * in the DES library -- if someone ever wants to disable DES,
 * this function will fail */
int EVP_read_pw_string(char *buf, int len, const char *prompt, int verify)
	{
	int ret;
	char buff[BUFSIZ];
	UI *ui;

	if ((prompt == NULL) && (prompt_string[0] != '\0'))
		prompt=prompt_string;
	ui = UI_new();
	UI_add_input_string(ui,prompt,0,buf,0,(len>=BUFSIZ)?BUFSIZ-1:len);
	if (verify)
		UI_add_verify_string(ui,prompt,0,
			buff,0,(len>=BUFSIZ)?BUFSIZ-1:len,buf);
	ret = UI_process(ui);
	UI_free(ui);
	OPENSSL_cleanse(buff,BUFSIZ);
	return ret;
	}

int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md, 
	     const unsigned char *salt, const unsigned char *data, int datal,
	     int count, unsigned char *key, unsigned char *iv)
	{
	EVP_MD_CTX c;
	unsigned char md_buf[EVP_MAX_MD_SIZE];
	int niv,nkey,addmd=0;
	unsigned int mds=0,i;

	nkey=type->key_len;
	niv=type->iv_len;
	OPENSSL_assert(nkey <= EVP_MAX_KEY_LENGTH);
	OPENSSL_assert(niv <= EVP_MAX_IV_LENGTH);

	if (data == NULL) return(nkey);

	EVP_MD_CTX_init(&c);
	for (;;)
		{
		EVP_DigestInit_ex(&c,md, NULL);
		if (addmd++)
			EVP_DigestUpdate(&c,&(md_buf[0]),mds);
		EVP_DigestUpdate(&c,data,datal);
		if (salt != NULL)
			EVP_DigestUpdate(&c,salt,PKCS5_SALT_LEN);
		EVP_DigestFinal_ex(&c,&(md_buf[0]),&mds);

		for (i=1; i<(unsigned int)count; i++)
			{
			EVP_DigestInit_ex(&c,md, NULL);
			EVP_DigestUpdate(&c,&(md_buf[0]),mds);
			EVP_DigestFinal_ex(&c,&(md_buf[0]),&mds);
			}
		i=0;
		if (nkey)
			{
			for (;;)
				{
				if (nkey == 0) break;
				if (i == mds) break;
				if (key != NULL)
					*(key++)=md_buf[i];
				nkey--;
				i++;
				}
			}
		if (niv && (i != mds))
			{
			for (;;)
				{
				if (niv == 0) break;
				if (i == mds) break;
				if (iv != NULL)
					*(iv++)=md_buf[i];
				niv--;
				i++;
				}
			}
		if ((nkey == 0) && (niv == 0)) break;
		}
	EVP_MD_CTX_cleanup(&c);
	OPENSSL_cleanse(&(md_buf[0]),EVP_MAX_MD_SIZE);
	return(type->key_len);
	}