evp_key.c

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/* crypto/evp/evp_key.c */
/* Copyright (C) 1995-1998 Eric Young ([email protected])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([email protected]).
 * 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 ([email protected]).
 * 
 * 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 ([email protected])"
 *    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 ([email protected])"
 * 
 * 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)
    {
    return EVP_read_pw_string_min(buf, 0, len, prompt, verify);
    }

int EVP_read_pw_string_min(char *buf, int min, 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,min,(len>=BUFSIZ)?BUFSIZ-1:len);
    if (verify)
        UI_add_verify_string(ui,prompt,0,
            buff,min,(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;
    int rv = 0;
    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 (;;)
        {
        if (!EVP_DigestInit_ex(&c,md, NULL))
            return 0;
        if (addmd++)
            if (!EVP_DigestUpdate(&c,&(md_buf[0]),mds))
                goto err;
        if (!EVP_DigestUpdate(&c,data,datal))
            goto err;
        if (salt != NULL)
            if (!EVP_DigestUpdate(&c,salt,PKCS5_SALT_LEN))
                goto err;
        if (!EVP_DigestFinal_ex(&c,&(md_buf[0]),&mds))
            goto err;

        for (i=1; i<(unsigned int)count; i++)
            {
            if (!EVP_DigestInit_ex(&c,md, NULL))
                goto err;
            if (!EVP_DigestUpdate(&c,&(md_buf[0]),mds))
                goto err;
            if (!EVP_DigestFinal_ex(&c,&(md_buf[0]),&mds))
                goto err;
            }
        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;
        }
    rv = type->key_len;
    err:
    EVP_MD_CTX_cleanup(&c);
    OPENSSL_cleanse(&(md_buf[0]),EVP_MAX_MD_SIZE);
    return rv;
    }