/*

 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (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

 */

#include <stdio.h>

#include <time.h>

#include <sys/types.h>

#include "internal/cryptlib.h"

#include <openssl/bn.h>

#include <openssl/evp.h>

#include <openssl/x509.h>

#include <openssl/objects.h>

#include <openssl/buffer.h>

#include "crypto/asn1.h"

#include "crypto/evp.h"

#ifndef NO_ASN1_OLD

int ASN1_sign(i2d_of_void *i2d, X509_ALGOR *algor1, X509_ALGOR *algor2,

              ASN1_BIT_STRING *signature, char *data, EVP_PKEY *pkey,

              const EVP_MD *type)

{

    EVP_MD_CTX *ctx = EVP_MD_CTX_new();

    unsigned char *p, *buf_in = NULL, *buf_out = NULL;

    int i, inl = 0, outl = 0;

    size_t inll = 0, outll = 0;

    X509_ALGOR *a;

    if (ctx == NULL) {

        ASN1err(ASN1_F_ASN1_SIGN, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    for (i = 0; i < 2; i++) {

        if (i == 0)

            a = algor1;

        else

            a = algor2;

        if (a == NULL)

            continue;

        if (type->pkey_type == NID_dsaWithSHA1) {

            /*

             * special case: RFC 2459 tells us to omit 'parameters' with

             * id-dsa-with-sha1

             */

            ASN1_TYPE_free(a->parameter);

            a->parameter = NULL;

        } else if ((a->parameter == NULL) ||

                   (a->parameter->type != V_ASN1_NULL)) {

            ASN1_TYPE_free(a->parameter);

            if ((a->parameter = ASN1_TYPE_new()) == NULL)

                goto err;

            a->parameter->type = V_ASN1_NULL;

        }

        ASN1_OBJECT_free(a->algorithm);

        a->algorithm = OBJ_nid2obj(type->pkey_type);

        if (a->algorithm == NULL) {

            ASN1err(ASN1_F_ASN1_SIGN, ASN1_R_UNKNOWN_OBJECT_TYPE);

            goto err;

        }

        if (a->algorithm->length == 0) {

            ASN1err(ASN1_F_ASN1_SIGN,

                    ASN1_R_THE_ASN1_OBJECT_IDENTIFIER_IS_NOT_KNOWN_FOR_THIS_MD);

            goto err;

        }

    }

    inl = i2d(data, NULL);

    if (inl <= 0) {

        ASN1err(ASN1_F_ASN1_SIGN, ERR_R_INTERNAL_ERROR);

        goto err;

    }

    inll = (size_t)inl;

    buf_in = OPENSSL_malloc(inll);

    outll = outl = EVP_PKEY_size(pkey);

    buf_out = OPENSSL_malloc(outll);

    if (buf_in == NULL || buf_out == NULL) {

        outl = 0;

        ASN1err(ASN1_F_ASN1_SIGN, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    p = buf_in;

    i2d(data, &p);

    if (!EVP_SignInit_ex(ctx, type, NULL)

        || !EVP_SignUpdate(ctx, (unsigned char *)buf_in, inl)

        || !EVP_SignFinal(ctx, (unsigned char *)buf_out,

                          (unsigned int *)&outl, pkey)) {

        outl = 0;

        ASN1err(ASN1_F_ASN1_SIGN, ERR_R_EVP_LIB);

        goto err;

    }

    OPENSSL_free(signature->data);

    signature->data = buf_out;

    buf_out = NULL;

    signature->length = outl;

    /*

     * In the interests of compatibility, I'll make sure that the bit string

     * has a 'not-used bits' value of 0

     */

    signature->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);

    signature->flags |= ASN1_STRING_FLAG_BITS_LEFT;

 err:

    EVP_MD_CTX_free(ctx);

    OPENSSL_clear_free((char *)buf_in, inll);

    OPENSSL_clear_free((char *)buf_out, outll);

    return outl;

}

#endif

int ASN1_item_sign(const ASN1_ITEM *it, X509_ALGOR *algor1,

                   X509_ALGOR *algor2, ASN1_BIT_STRING *signature, void *asn,

                   EVP_PKEY *pkey, const EVP_MD *type)

{

    int rv;

    EVP_MD_CTX *ctx = EVP_MD_CTX_new();

    if (ctx == NULL) {

        ASN1err(ASN1_F_ASN1_ITEM_SIGN, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    if (!EVP_DigestSignInit(ctx, NULL, type, NULL, pkey)) {

        EVP_MD_CTX_free(ctx);

        return 0;

    }

    rv = ASN1_item_sign_ctx(it, algor1, algor2, signature, asn, ctx);

    EVP_MD_CTX_free(ctx);

    return rv;

}

int ASN1_item_sign_ctx(const ASN1_ITEM *it,

                       X509_ALGOR *algor1, X509_ALGOR *algor2,

                       ASN1_BIT_STRING *signature, void *asn, EVP_MD_CTX *ctx)

{

    const EVP_MD *type;

    EVP_PKEY *pkey;

    unsigned char *buf_in = NULL, *buf_out = NULL;

    size_t inl = 0, outl = 0, outll = 0;

    int signid, paramtype, buf_len = 0;

    int rv;

    type = EVP_MD_CTX_md(ctx);

    pkey = EVP_PKEY_CTX_get0_pkey(EVP_MD_CTX_pkey_ctx(ctx));

    if (pkey == NULL) {

        ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ASN1_R_CONTEXT_NOT_INITIALISED);

        goto err;

    }

    if (pkey->ameth == NULL) {

        ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ASN1_R_DIGEST_AND_KEY_TYPE_NOT_SUPPORTED);

        goto err;

    }

    if (pkey->ameth->item_sign) {

        rv = pkey->ameth->item_sign(ctx, it, asn, algor1, algor2, signature);

        if (rv == 1)

            outl = signature->length;

        /*-

         * Return value meanings:

         * <=0: error.

         *   1: method does everything.

         *   2: carry on as normal.

         *   3: ASN1 method sets algorithm identifiers: just sign.

         */

        if (rv <= 0)

            ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ERR_R_EVP_LIB);

        if (rv <= 1)

            goto err;

    } else {

        rv = 2;

    }

    if (rv == 2) {

        if (type == NULL) {

            ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ASN1_R_CONTEXT_NOT_INITIALISED);

            goto err;

        }

        if (!OBJ_find_sigid_by_algs(&signid,

                                    EVP_MD_nid(type),

                                    pkey->ameth->pkey_id)) {

            ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX,

                    ASN1_R_DIGEST_AND_KEY_TYPE_NOT_SUPPORTED);

            goto err;

        }

        if (pkey->ameth->pkey_flags & ASN1_PKEY_SIGPARAM_NULL)

            paramtype = V_ASN1_NULL;

        else

            paramtype = V_ASN1_UNDEF;

        if (algor1)

            X509_ALGOR_set0(algor1, OBJ_nid2obj(signid), paramtype, NULL);

        if (algor2)

            X509_ALGOR_set0(algor2, OBJ_nid2obj(signid), paramtype, NULL);

    }

    buf_len = ASN1_item_i2d(asn, &buf_in, it);

    if (buf_len <= 0) {

        outl = 0;

        ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ERR_R_INTERNAL_ERROR);

        goto err;

    }

    inl = buf_len;

    outll = outl = EVP_PKEY_size(pkey);

    buf_out = OPENSSL_malloc(outll);

    if (buf_in == NULL || buf_out == NULL) {

        outl = 0;

        ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    if (!EVP_DigestSign(ctx, buf_out, &outl, buf_in, inl)) {

        outl = 0;

        ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ERR_R_EVP_LIB);

        goto err;

    }

    OPENSSL_free(signature->data);

    signature->data = buf_out;

    buf_out = NULL;

    signature->length = outl;

    /*

     * In the interests of compatibility, I'll make sure that the bit string

     * has a 'not-used bits' value of 0

     */

    signature->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);

    signature->flags |= ASN1_STRING_FLAG_BITS_LEFT;

 err:

    OPENSSL_clear_free((char *)buf_in, inl);

    OPENSSL_clear_free((char *)buf_out, outll);

    return outl;

}