openssl/crypto/evp/evp_key.c

/* crypto/evp/evp_key.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * 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 (tjh@cryptsoft.com).
 *
 * 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 (eay@cryptsoft.com)"
 *    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 (tjh@cryptsoft.com)"
 *
 * 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 (;;) {
        if (!EVP_DigestInit_ex(&c, md, NULL))
            return 0;
        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);
}