/*

 * Copyright 2008-2018 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 "internal/cryptlib.h"

#include <openssl/asn1t.h>

#include <openssl/pem.h>

#include <openssl/x509v3.h>

#include <openssl/err.h>

#include <openssl/cms.h>

#include <openssl/rand.h>

#include "cms_lcl.h"

/* CMS EncryptedData Utilities */

/* Return BIO based on EncryptedContentInfo and key */

BIO *cms_EncryptedContent_init_bio(CMS_EncryptedContentInfo *ec)

{

    BIO *b;

    EVP_CIPHER_CTX *ctx;

    const EVP_CIPHER *ciph;

    X509_ALGOR *calg = ec->contentEncryptionAlgorithm;

    unsigned char iv[EVP_MAX_IV_LENGTH], *piv = NULL;

    unsigned char *tkey = NULL;

    size_t tkeylen = 0;

    int ok = 0;

    int enc, keep_key = 0;

    enc = ec->cipher ? 1 : 0;

    b = BIO_new(BIO_f_cipher());

    if (b == NULL) {

        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);

        return NULL;

    }

    BIO_get_cipher_ctx(b, &ctx);

    if (enc) {

        ciph = ec->cipher;

        /*

         * If not keeping key set cipher to NULL so subsequent calls decrypt.

         */

        if (ec->key)

            ec->cipher = NULL;

    } else {

        ciph = EVP_get_cipherbyobj(calg->algorithm);

        if (!ciph) {

            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, CMS_R_UNKNOWN_CIPHER);

            goto err;

        }

    }

    if (EVP_CipherInit_ex(ctx, ciph, NULL, NULL, NULL, enc) <= 0) {

        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,

               CMS_R_CIPHER_INITIALISATION_ERROR);

        goto err;

    }

    if (enc) {

        int ivlen;

        calg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_type(ctx));

        /* Generate a random IV if we need one */

        ivlen = EVP_CIPHER_CTX_iv_length(ctx);

        if (ivlen > 0) {

            if (RAND_bytes(iv, ivlen) <= 0)

                goto err;

            piv = iv;

        }

    } else if (EVP_CIPHER_asn1_to_param(ctx, calg->parameter) <= 0) {

        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,

               CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);

        goto err;

    }

    tkeylen = EVP_CIPHER_CTX_key_length(ctx);

    /* Generate random session key */

    if (!enc || !ec->key) {

        tkey = OPENSSL_malloc(tkeylen);

        if (tkey == NULL) {

            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);

            goto err;

        }

        if (EVP_CIPHER_CTX_rand_key(ctx, tkey) <= 0)

            goto err;

    }

    if (!ec->key) {

        ec->key = tkey;

        ec->keylen = tkeylen;

        tkey = NULL;

        if (enc)

            keep_key = 1;

        else

            ERR_clear_error();

    }

    if (ec->keylen != tkeylen) {

        /* If necessary set key length */

        if (EVP_CIPHER_CTX_set_key_length(ctx, ec->keylen) <= 0) {

            /*

             * Only reveal failure if debugging so we don't leak information

             * which may be useful in MMA.

             */

            if (enc || ec->debug) {

                CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,

                       CMS_R_INVALID_KEY_LENGTH);

                goto err;

            } else {

                /* Use random key */

                OPENSSL_clear_free(ec->key, ec->keylen);

                ec->key = tkey;

                ec->keylen = tkeylen;

                tkey = NULL;

                ERR_clear_error();

            }

        }

    }

    if (EVP_CipherInit_ex(ctx, NULL, NULL, ec->key, piv, enc) <= 0) {

        CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,

               CMS_R_CIPHER_INITIALISATION_ERROR);

        goto err;

    }

    if (enc) {

        calg->parameter = ASN1_TYPE_new();

        if (calg->parameter == NULL) {

            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO, ERR_R_MALLOC_FAILURE);

            goto err;

        }

        if (EVP_CIPHER_param_to_asn1(ctx, calg->parameter) <= 0) {

            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT_BIO,

                   CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);

            goto err;

        }

        /* If parameter type not set omit parameter */

        if (calg->parameter->type == V_ASN1_UNDEF) {

            ASN1_TYPE_free(calg->parameter);

            calg->parameter = NULL;

        }

    }

    ok = 1;

 err:

    if (!keep_key || !ok) {

        OPENSSL_clear_free(ec->key, ec->keylen);

        ec->key = NULL;

    }

    OPENSSL_clear_free(tkey, tkeylen);

    if (ok)

        return b;

    BIO_free(b);

    return NULL;

}

int cms_EncryptedContent_init(CMS_EncryptedContentInfo *ec,

                              const EVP_CIPHER *cipher,

                              const unsigned char *key, size_t keylen)

{

    ec->cipher = cipher;

    if (key) {

        if ((ec->key = OPENSSL_malloc(keylen)) == NULL) {

            CMSerr(CMS_F_CMS_ENCRYPTEDCONTENT_INIT, ERR_R_MALLOC_FAILURE);

            return 0;

        }

        memcpy(ec->key, key, keylen);

    }

    ec->keylen = keylen;

    if (cipher)

        ec->contentType = OBJ_nid2obj(NID_pkcs7_data);

    return 1;

}

int CMS_EncryptedData_set1_key(CMS_ContentInfo *cms, const EVP_CIPHER *ciph,

                               const unsigned char *key, size_t keylen)

{

    CMS_EncryptedContentInfo *ec;

    if (!key || !keylen) {

        CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NO_KEY);

        return 0;

    }

    if (ciph) {

        cms->d.encryptedData = M_ASN1_new_of(CMS_EncryptedData);

        if (!cms->d.encryptedData) {

            CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, ERR_R_MALLOC_FAILURE);

            return 0;

        }

        cms->contentType = OBJ_nid2obj(NID_pkcs7_encrypted);

        cms->d.encryptedData->version = 0;

    } else if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_encrypted) {

        CMSerr(CMS_F_CMS_ENCRYPTEDDATA_SET1_KEY, CMS_R_NOT_ENCRYPTED_DATA);

        return 0;

    }

    ec = cms->d.encryptedData->encryptedContentInfo;

    return cms_EncryptedContent_init(ec, ciph, key, keylen);

}

BIO *cms_EncryptedData_init_bio(CMS_ContentInfo *cms)

{

    CMS_EncryptedData *enc = cms->d.encryptedData;

    if (enc->encryptedContentInfo->cipher && enc->unprotectedAttrs)

        enc->version = 2;

    return cms_EncryptedContent_init_bio(enc->encryptedContentInfo);

}