/*

 * Copyright 1995-2020 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

 */

/*

 * RSA low level APIs are deprecated for public use, but still ok for

 * internal use.

 */

#include "internal/deprecated.h"

#include <stdio.h>

#include "internal/cryptlib.h"

#include <openssl/bn.h>

#include <openssl/rsa.h>

#include <openssl/objects.h>

#include <openssl/x509.h>

int RSA_sign_ASN1_OCTET_STRING(int type,

                               const unsigned char *m, unsigned int m_len,

                               unsigned char *sigret, unsigned int *siglen,

                               RSA *rsa)

{

    ASN1_OCTET_STRING sig;

    int i, j, ret = 1;

    unsigned char *p, *s;

    sig.type = V_ASN1_OCTET_STRING;

    sig.length = m_len;

    sig.data = (unsigned char *)m;

    i = i2d_ASN1_OCTET_STRING(&sig, NULL);

    j = RSA_size(rsa);

    if (i > (j - RSA_PKCS1_PADDING_SIZE)) {

        ERR_raise(ERR_LIB_RSA, RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY);

        return 0;

    }

    s = OPENSSL_malloc((unsigned int)j + 1);

    if (s == NULL)

        return 0;

    p = s;

    i2d_ASN1_OCTET_STRING(&sig, &p);

    i = RSA_private_encrypt(i, s, sigret, rsa, RSA_PKCS1_PADDING);

    if (i <= 0)

        ret = 0;

    else

        *siglen = i;

    OPENSSL_clear_free(s, (unsigned int)j + 1);

    return ret;

}

int RSA_verify_ASN1_OCTET_STRING(int dtype,

                                 const unsigned char *m,

                                 unsigned int m_len, unsigned char *sigbuf,

                                 unsigned int siglen, RSA *rsa)

{

    int i, ret = 0;

    unsigned char *s;

    const unsigned char *p;

    ASN1_OCTET_STRING *sig = NULL;

    if (siglen != (unsigned int)RSA_size(rsa)) {

        ERR_raise(ERR_LIB_RSA, RSA_R_WRONG_SIGNATURE_LENGTH);

        return 0;

    }

    s = OPENSSL_malloc((unsigned int)siglen);

    if (s == NULL)

        goto err;

    i = RSA_public_decrypt((int)siglen, sigbuf, s, rsa, RSA_PKCS1_PADDING);

    if (i <= 0)

        goto err;

    p = s;

    sig = d2i_ASN1_OCTET_STRING(NULL, &p, (long)i);

    if (sig == NULL)

        goto err;

    if (((unsigned int)sig->length != m_len) ||

        (memcmp(m, sig->data, m_len) != 0)) {

        ERR_raise(ERR_LIB_RSA, RSA_R_BAD_SIGNATURE);

    } else {

        ret = 1;

    }

 err:

    ASN1_OCTET_STRING_free(sig);

    OPENSSL_clear_free(s, (unsigned int)siglen);

    return ret;

}