/* $OpenBSD: cms_env.c,v 1.24 2021/09/08 14:33:02 tb Exp $ */
/*
 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
 * project.
 */
/* ====================================================================
 * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
 *
 * 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 above 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 acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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.
 * ====================================================================
 */

#include <string.h>

#include "cryptlib.h"
#include <openssl/asn1t.h>
#include <openssl/pem.h>
#include <openssl/x509v3.h>
#include <openssl/err.h>
#include <openssl/cms.h>
#include <openssl/aes.h>
#include "cms_lcl.h"
#include "asn1/asn1_locl.h"
#include "evp/evp_locl.h"

/* CMS EnvelopedData Utilities */

CMS_EnvelopedData *
cms_get0_enveloped(CMS_ContentInfo *cms)
{
        if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_enveloped) {
                CMSerror(CMS_R_CONTENT_TYPE_NOT_ENVELOPED_DATA);
                return NULL;
        }
        return cms->d.envelopedData;
}

static CMS_EnvelopedData *
cms_enveloped_data_init(CMS_ContentInfo *cms)
{
        if (cms->d.other == NULL) {
                cms->d.envelopedData = (CMS_EnvelopedData *)ASN1_item_new(&CMS_EnvelopedData_it);
                if (!cms->d.envelopedData) {
                        CMSerror(ERR_R_MALLOC_FAILURE);
                        return NULL;
                }
                cms->d.envelopedData->version = 0;
                cms->d.envelopedData->encryptedContentInfo->contentType =
                        OBJ_nid2obj(NID_pkcs7_data);
                ASN1_OBJECT_free(cms->contentType);
                cms->contentType = OBJ_nid2obj(NID_pkcs7_enveloped);
                return cms->d.envelopedData;
        }
        return cms_get0_enveloped(cms);
}

int
cms_env_asn1_ctrl(CMS_RecipientInfo *ri, int cmd)
{
        EVP_PKEY *pkey;
        int i;

        if (ri->type == CMS_RECIPINFO_TRANS)
                pkey = ri->d.ktri->pkey;
        else if (ri->type == CMS_RECIPINFO_AGREE) {
                EVP_PKEY_CTX *pctx = ri->d.kari->pctx;
                if (!pctx)
                        return 0;
                pkey = EVP_PKEY_CTX_get0_pkey(pctx);
                if (!pkey)
                        return 0;
        } else
                return 0;
        if (!pkey->ameth || !pkey->ameth->pkey_ctrl)
                return 1;
        i = pkey->ameth->pkey_ctrl(pkey, ASN1_PKEY_CTRL_CMS_ENVELOPE, cmd, ri);
        if (i == -2) {
                CMSerror(CMS_R_NOT_SUPPORTED_FOR_THIS_KEY_TYPE);
                return 0;
        }
        if (i <= 0) {
                CMSerror(CMS_R_CTRL_FAILURE);
                return 0;
        }

        return 1;
}

STACK_OF(CMS_RecipientInfo) *
CMS_get0_RecipientInfos(CMS_ContentInfo *cms)
{
        CMS_EnvelopedData *env;

        env = cms_get0_enveloped(cms);
        if (!env)
                return NULL;

        return env->recipientInfos;
}

int
CMS_RecipientInfo_type(CMS_RecipientInfo *ri)
{
        return ri->type;
}

EVP_PKEY_CTX *
CMS_RecipientInfo_get0_pkey_ctx(CMS_RecipientInfo *ri)
{
        if (ri->type == CMS_RECIPINFO_TRANS)
                return ri->d.ktri->pctx;
        else if (ri->type == CMS_RECIPINFO_AGREE)
                return ri->d.kari->pctx;

        return NULL;
}

CMS_ContentInfo *
CMS_EnvelopedData_create(const EVP_CIPHER *cipher)
{
        CMS_ContentInfo *cms;
        CMS_EnvelopedData *env;

        cms = CMS_ContentInfo_new();
        if (cms == NULL)
                goto merr;
        env = cms_enveloped_data_init(cms);
        if (env == NULL)
                goto merr;
        if (!cms_EncryptedContent_init(env->encryptedContentInfo, cipher,
            NULL, 0))
                goto merr;

        return cms;

 merr:
        CMS_ContentInfo_free(cms);
        CMSerror(ERR_R_MALLOC_FAILURE);
        return NULL;
}

/* Key Transport Recipient Info (KTRI) routines */

/* Initialise a ktri based on passed certificate and key */

static int
cms_RecipientInfo_ktri_init(CMS_RecipientInfo *ri, X509 *recip, EVP_PKEY *pk,
    unsigned int flags)
{
        CMS_KeyTransRecipientInfo *ktri;
        int idtype;

        ri->d.ktri = (CMS_KeyTransRecipientInfo *)ASN1_item_new(&CMS_KeyTransRecipientInfo_it);
        if (!ri->d.ktri)
                return 0;
        ri->type = CMS_RECIPINFO_TRANS;

        ktri = ri->d.ktri;

        if (flags & CMS_USE_KEYID) {
                ktri->version = 2;
                idtype = CMS_RECIPINFO_KEYIDENTIFIER;
        } else {
                ktri->version = 0;
                idtype = CMS_RECIPINFO_ISSUER_SERIAL;
        }

        /*
         * Not a typo: RecipientIdentifier and SignerIdentifier are the same
         * structure.
         */

        if (!cms_set1_SignerIdentifier(ktri->rid, recip, idtype))
                return 0;

        X509_up_ref(recip);
        EVP_PKEY_up_ref(pk);

        ktri->pkey = pk;
        ktri->recip = recip;

        if (flags & CMS_KEY_PARAM) {
                ktri->pctx = EVP_PKEY_CTX_new(ktri->pkey, NULL);
                if (ktri->pctx == NULL)
                        return 0;
                if (EVP_PKEY_encrypt_init(ktri->pctx) <= 0)
                        return 0;
        } else if (!cms_env_asn1_ctrl(ri, 0))
                return 0;

        return 1;
}

/*
 * Add a recipient certificate using appropriate type of RecipientInfo
 */

CMS_RecipientInfo *
CMS_add1_recipient_cert(CMS_ContentInfo *cms, X509 *recip, unsigned int flags)
{
        CMS_RecipientInfo *ri = NULL;
        CMS_EnvelopedData *env;
        EVP_PKEY *pk = NULL;

        env = cms_get0_enveloped(cms);
        if (!env)
                goto err;

        /* Initialize recipient info */
        ri = (CMS_RecipientInfo *)ASN1_item_new(&CMS_RecipientInfo_it);
        if (!ri)
                goto merr;

        pk = X509_get0_pubkey(recip);
        if (!pk) {
                CMSerror(CMS_R_ERROR_GETTING_PUBLIC_KEY);
                goto err;
        }

        switch (cms_pkey_get_ri_type(pk)) {

        case CMS_RECIPINFO_TRANS:
                if (!cms_RecipientInfo_ktri_init(ri, recip, pk, flags))
                        goto err;
                break;

        case CMS_RECIPINFO_AGREE:
                if (!cms_RecipientInfo_kari_init(ri, recip, pk, flags))
                        goto err;
                break;

        default:
                CMSerror(CMS_R_NOT_SUPPORTED_FOR_THIS_KEY_TYPE);
                goto err;

        }

        if (!sk_CMS_RecipientInfo_push(env->recipientInfos, ri))
                goto merr;

        return ri;

 merr:
        CMSerror(ERR_R_MALLOC_FAILURE);
 err:
        ASN1_item_free((ASN1_VALUE *)ri, &CMS_RecipientInfo_it);
        return NULL;
}

int
CMS_RecipientInfo_ktri_get0_algs(CMS_RecipientInfo *ri, EVP_PKEY **pk,
    X509 **recip, X509_ALGOR **palg)
{
        CMS_KeyTransRecipientInfo *ktri;

        if (ri->type != CMS_RECIPINFO_TRANS) {
                CMSerror(CMS_R_NOT_KEY_TRANSPORT);
                return 0;
        }

        ktri = ri->d.ktri;

        if (pk)
                *pk = ktri->pkey;
        if (recip)
                *recip = ktri->recip;
        if (palg)
                *palg = ktri->keyEncryptionAlgorithm;

        return 1;
}

int
CMS_RecipientInfo_ktri_get0_signer_id(CMS_RecipientInfo *ri,
    ASN1_OCTET_STRING **keyid, X509_NAME **issuer, ASN1_INTEGER **sno)
{
        CMS_KeyTransRecipientInfo *ktri;

        if (ri->type != CMS_RECIPINFO_TRANS) {
                CMSerror(CMS_R_NOT_KEY_TRANSPORT);
                return 0;
        }
        ktri = ri->d.ktri;

        return cms_SignerIdentifier_get0_signer_id(ktri->rid, keyid, issuer, sno);
}

int
CMS_RecipientInfo_ktri_cert_cmp(CMS_RecipientInfo *ri, X509 *cert)
{
        if (ri->type != CMS_RECIPINFO_TRANS) {
                CMSerror(CMS_R_NOT_KEY_TRANSPORT);
                return -2;
        }

        return cms_SignerIdentifier_cert_cmp(ri->d.ktri->rid, cert);
}

int
CMS_RecipientInfo_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pkey)
{
        if (ri->type != CMS_RECIPINFO_TRANS) {
                CMSerror(CMS_R_NOT_KEY_TRANSPORT);
                return 0;
        }
        EVP_PKEY_free(ri->d.ktri->pkey);
        ri->d.ktri->pkey = pkey;

        return 1;
}

/* Encrypt content key in key transport recipient info */

static int
cms_RecipientInfo_ktri_encrypt(CMS_ContentInfo *cms, CMS_RecipientInfo *ri)
{
        CMS_KeyTransRecipientInfo *ktri;
        CMS_EncryptedContentInfo *ec;
        EVP_PKEY_CTX *pctx;
        unsigned char *ek = NULL;
        size_t eklen;

        int ret = 0;

        if (ri->type != CMS_RECIPINFO_TRANS) {
                CMSerror(CMS_R_NOT_KEY_TRANSPORT);
                return 0;
        }
        ktri = ri->d.ktri;
        ec = cms->d.envelopedData->encryptedContentInfo;

        pctx = ktri->pctx;

        if (pctx) {
                if (!cms_env_asn1_ctrl(ri, 0))
                        goto err;
        } else {
                pctx = EVP_PKEY_CTX_new(ktri->pkey, NULL);
                if (pctx == NULL)
                        return 0;

                if (EVP_PKEY_encrypt_init(pctx) <= 0)
                        goto err;
        }

        if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_ENCRYPT,
                                      EVP_PKEY_CTRL_CMS_ENCRYPT, 0, ri) <= 0) {
                CMSerror(CMS_R_CTRL_ERROR);
                goto err;
        }

        if (EVP_PKEY_encrypt(pctx, NULL, &eklen, ec->key, ec->keylen) <= 0)
                goto err;

        ek = malloc(eklen);

        if (ek == NULL) {
                CMSerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        if (EVP_PKEY_encrypt(pctx, ek, &eklen, ec->key, ec->keylen) <= 0)
                goto err;

        ASN1_STRING_set0(ktri->encryptedKey, ek, eklen);
        ek = NULL;

        ret = 1;

 err:
        EVP_PKEY_CTX_free(pctx);
        ktri->pctx = NULL;
        free(ek);

        return ret;
}

/* Decrypt content key from KTRI */

static int
cms_RecipientInfo_ktri_decrypt(CMS_ContentInfo *cms, CMS_RecipientInfo *ri)
{
        CMS_KeyTransRecipientInfo *ktri = ri->d.ktri;
        EVP_PKEY *pkey = ktri->pkey;
        unsigned char *ek = NULL;
        size_t eklen;
        size_t fixlen = 0;
        int ret = 0;
        CMS_EncryptedContentInfo *ec;

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

        if (ktri->pkey == NULL) {
                CMSerror(CMS_R_NO_PRIVATE_KEY);
                return 0;
        }

        if (cms->d.envelopedData->encryptedContentInfo->havenocert &&
            !cms->d.envelopedData->encryptedContentInfo->debug) {
                X509_ALGOR *calg = ec->contentEncryptionAlgorithm;
                const EVP_CIPHER *ciph;

                if ((ciph = EVP_get_cipherbyobj(calg->algorithm)) == NULL) {
                        CMSerror(CMS_R_UNKNOWN_CIPHER);
                        return 0;
                }

                fixlen = EVP_CIPHER_key_length(ciph);
        }

        ktri->pctx = EVP_PKEY_CTX_new(pkey, NULL);
        if (ktri->pctx == NULL)
                return 0;

        if (EVP_PKEY_decrypt_init(ktri->pctx) <= 0)
                goto err;

        if (!cms_env_asn1_ctrl(ri, 1))
                goto err;

        if (EVP_PKEY_CTX_ctrl(ktri->pctx, -1, EVP_PKEY_OP_DECRYPT,
            EVP_PKEY_CTRL_CMS_DECRYPT, 0, ri) <= 0) {
                CMSerror(CMS_R_CTRL_ERROR);
                goto err;
        }

        if (EVP_PKEY_decrypt(ktri->pctx, NULL, &eklen, ktri->encryptedKey->data,
            ktri->encryptedKey->length) <= 0 || eklen == 0 ||
            (fixlen != 0 && eklen != fixlen)) {
                CMSerror(CMS_R_CMS_LIB);
                goto err;
        }

        ek = malloc(eklen);

        if (ek == NULL) {
                CMSerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        if (EVP_PKEY_decrypt(ktri->pctx, ek, &eklen, ktri->encryptedKey->data,
            ktri->encryptedKey->length) <= 0) {
                CMSerror(CMS_R_CMS_LIB);
                goto err;
        }

        ret = 1;

        freezero(ec->key, ec->keylen);
        ec->key = ek;
        ec->keylen = eklen;

 err:
        EVP_PKEY_CTX_free(ktri->pctx);
        ktri->pctx = NULL;
        if (!ret)
                free(ek);

        return ret;
}

/* Key Encrypted Key (KEK) RecipientInfo routines */

int
CMS_RecipientInfo_kekri_id_cmp(CMS_RecipientInfo *ri, const unsigned char *id,
    size_t idlen)
{
        ASN1_OCTET_STRING tmp_os;
        CMS_KEKRecipientInfo *kekri;

        if (ri->type != CMS_RECIPINFO_KEK) {
                CMSerror(CMS_R_NOT_KEK);
                return -2;
        }
        kekri = ri->d.kekri;
        tmp_os.type = V_ASN1_OCTET_STRING;
        tmp_os.flags = 0;
        tmp_os.data = (unsigned char *)id;
        tmp_os.length = (int)idlen;

        return ASN1_OCTET_STRING_cmp(&tmp_os, kekri->kekid->keyIdentifier);
}

/* For now hard code AES key wrap info */

static size_t
aes_wrap_keylen(int nid)
{
        switch (nid) {
        case NID_id_aes128_wrap:
                return 16;

        case NID_id_aes192_wrap:
                return 24;

        case NID_id_aes256_wrap:
                return 32;

        default:
                return 0;
        }
}

CMS_RecipientInfo *
CMS_add0_recipient_key(CMS_ContentInfo *cms, int nid, unsigned char *key,
    size_t keylen, unsigned char *id, size_t idlen, ASN1_GENERALIZEDTIME *date,
    ASN1_OBJECT *otherTypeId, ASN1_TYPE *otherType)
{
        CMS_RecipientInfo *ri = NULL;
        CMS_EnvelopedData *env;
        CMS_KEKRecipientInfo *kekri;

        env = cms_get0_enveloped(cms);
        if (!env)
                goto err;

        if (nid == NID_undef) {
                switch (keylen) {
                case 16:
                        nid = NID_id_aes128_wrap;
                        break;

                case 24:
                        nid = NID_id_aes192_wrap;
                        break;

                case 32:
                        nid = NID_id_aes256_wrap;
                        break;

                default:
                        CMSerror(CMS_R_INVALID_KEY_LENGTH);
                        goto err;
                }

        } else {

                size_t exp_keylen = aes_wrap_keylen(nid);

                if (!exp_keylen) {
                        CMSerror(CMS_R_UNSUPPORTED_KEK_ALGORITHM);
                        goto err;
                }

                if (keylen != exp_keylen) {
                        CMSerror(CMS_R_INVALID_KEY_LENGTH);
                        goto err;
                }

        }

        /* Initialize recipient info */
        ri = (CMS_RecipientInfo *)ASN1_item_new(&CMS_RecipientInfo_it);
        if (!ri)
                goto merr;

        ri->d.kekri = (CMS_KEKRecipientInfo *)ASN1_item_new(&CMS_KEKRecipientInfo_it);
        if (!ri->d.kekri)
                goto merr;
        ri->type = CMS_RECIPINFO_KEK;

        kekri = ri->d.kekri;

        if (otherTypeId) {
                kekri->kekid->other = (CMS_OtherKeyAttribute *)ASN1_item_new(&CMS_OtherKeyAttribute_it);
                if (kekri->kekid->other == NULL)
                        goto merr;
        }

        if (!sk_CMS_RecipientInfo_push(env->recipientInfos, ri))
                goto merr;

        /* After this point no calls can fail */

        kekri->version = 4;

        kekri->key = key;
        kekri->keylen = keylen;

        ASN1_STRING_set0(kekri->kekid->keyIdentifier, id, idlen);

        kekri->kekid->date = date;

        if (kekri->kekid->other) {
                kekri->kekid->other->keyAttrId = otherTypeId;
                kekri->kekid->other->keyAttr = otherType;
        }

        X509_ALGOR_set0(kekri->keyEncryptionAlgorithm,
                                OBJ_nid2obj(nid), V_ASN1_UNDEF, NULL);

        return ri;

 merr:
        CMSerror(ERR_R_MALLOC_FAILURE);
 err:
        ASN1_item_free((ASN1_VALUE *)ri, &CMS_RecipientInfo_it);
        return NULL;
}

int
CMS_RecipientInfo_kekri_get0_id(CMS_RecipientInfo *ri, X509_ALGOR **palg,
    ASN1_OCTET_STRING **pid, ASN1_GENERALIZEDTIME **pdate,
    ASN1_OBJECT **potherid, ASN1_TYPE **pothertype)
{
        CMS_KEKIdentifier *rkid;

        if (ri->type != CMS_RECIPINFO_KEK) {
                CMSerror(CMS_R_NOT_KEK);
                return 0;
        }
        rkid = ri->d.kekri->kekid;
        if (palg)
                *palg = ri->d.kekri->keyEncryptionAlgorithm;
        if (pid)
                *pid = rkid->keyIdentifier;
        if (pdate)
                *pdate = rkid->date;
        if (potherid) {
                if (rkid->other)
                        *potherid = rkid->other->keyAttrId;
                else
                        *potherid = NULL;
        }
        if (pothertype) {
                if (rkid->other)
                        *pothertype = rkid->other->keyAttr;
                else
                        *pothertype = NULL;
        }

        return 1;
}

int
CMS_RecipientInfo_set0_key(CMS_RecipientInfo *ri, unsigned char *key,
    size_t keylen)
{
        CMS_KEKRecipientInfo *kekri;

        if (ri->type != CMS_RECIPINFO_KEK) {
                CMSerror(CMS_R_NOT_KEK);
                return 0;
        }

        kekri = ri->d.kekri;
        kekri->key = key;
        kekri->keylen = keylen;
        return 1;
}

/* Encrypt content key in KEK recipient info */

static int
cms_RecipientInfo_kekri_encrypt(CMS_ContentInfo *cms, CMS_RecipientInfo *ri)
{
        CMS_EncryptedContentInfo *ec;
        CMS_KEKRecipientInfo *kekri;
        AES_KEY actx;
        unsigned char *wkey = NULL;
        int wkeylen;
        int r = 0;

        ec = cms->d.envelopedData->encryptedContentInfo;
        kekri = ri->d.kekri;

        if (!kekri->key) {
                CMSerror(CMS_R_NO_KEY);
                return 0;
        }

        if (AES_set_encrypt_key(kekri->key, kekri->keylen << 3, &actx)) {
                CMSerror(CMS_R_ERROR_SETTING_KEY);
                goto err;
        }

        wkey = malloc(ec->keylen + 8);
        if (wkey == NULL) {
                CMSerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        wkeylen = AES_wrap_key(&actx, NULL, wkey, ec->key, ec->keylen);
        if (wkeylen <= 0) {
                CMSerror(CMS_R_WRAP_ERROR);
                goto err;
        }

        ASN1_STRING_set0(kekri->encryptedKey, wkey, wkeylen);

        r = 1;

 err:
        if (!r)
                free(wkey);
        explicit_bzero(&actx, sizeof(actx));

        return r;
}

/* Decrypt content key in KEK recipient info */

static int
cms_RecipientInfo_kekri_decrypt(CMS_ContentInfo *cms, CMS_RecipientInfo *ri)
{
        CMS_EncryptedContentInfo *ec;
        CMS_KEKRecipientInfo *kekri;
        AES_KEY actx;
        unsigned char *ukey = NULL;
        int ukeylen;
        int r = 0, wrap_nid;

        ec = cms->d.envelopedData->encryptedContentInfo;
        kekri = ri->d.kekri;

        if (!kekri->key) {
                CMSerror(CMS_R_NO_KEY);
                return 0;
        }

        wrap_nid = OBJ_obj2nid(kekri->keyEncryptionAlgorithm->algorithm);
        if (aes_wrap_keylen(wrap_nid) != kekri->keylen) {
                CMSerror(CMS_R_INVALID_KEY_LENGTH);
                return 0;
        }

        /* If encrypted key length is invalid don't bother */

        if (kekri->encryptedKey->length < 16) {
                CMSerror(CMS_R_INVALID_ENCRYPTED_KEY_LENGTH);
                goto err;
        }

        if (AES_set_decrypt_key(kekri->key, kekri->keylen << 3, &actx)) {
                CMSerror(CMS_R_ERROR_SETTING_KEY);
                goto err;
        }

        ukey = malloc(kekri->encryptedKey->length - 8);
        if (ukey == NULL) {
                CMSerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        ukeylen = AES_unwrap_key(&actx, NULL, ukey, kekri->encryptedKey->data,
            kekri->encryptedKey->length);

        if (ukeylen <= 0) {
                CMSerror(CMS_R_UNWRAP_ERROR);
                goto err;
        }

        freezero(ec->key, ec->keylen);
        ec->key = ukey;
        ec->keylen = ukeylen;

        r = 1;

 err:

        if (!r)
                free(ukey);
        explicit_bzero(&actx, sizeof(actx));

        return r;
}

int
CMS_RecipientInfo_decrypt(CMS_ContentInfo *cms, CMS_RecipientInfo *ri)
{
        switch (ri->type) {
        case CMS_RECIPINFO_TRANS:
                return cms_RecipientInfo_ktri_decrypt(cms, ri);

        case CMS_RECIPINFO_KEK:
                return cms_RecipientInfo_kekri_decrypt(cms, ri);

        case CMS_RECIPINFO_PASS:
                return cms_RecipientInfo_pwri_crypt(cms, ri, 0);

        default:
                CMSerror(CMS_R_UNSUPPORTED_RECIPIENTINFO_TYPE);
                return 0;
        }
}

int
CMS_RecipientInfo_encrypt(CMS_ContentInfo *cms, CMS_RecipientInfo *ri)
{
        switch (ri->type) {
        case CMS_RECIPINFO_TRANS:
                return cms_RecipientInfo_ktri_encrypt(cms, ri);

        case CMS_RECIPINFO_AGREE:
                return cms_RecipientInfo_kari_encrypt(cms, ri);

        case CMS_RECIPINFO_KEK:
                return cms_RecipientInfo_kekri_encrypt(cms, ri);

        case CMS_RECIPINFO_PASS:
                return cms_RecipientInfo_pwri_crypt(cms, ri, 1);

        default:
                CMSerror(CMS_R_UNSUPPORTED_RECIPIENT_TYPE);
                return 0;
        }
}

/* Check structures and fixup version numbers (if necessary) */

static void
cms_env_set_originfo_version(CMS_EnvelopedData *env)
{
        CMS_OriginatorInfo *org = env->originatorInfo;
        int i;

        if (org == NULL)
                return;
        for (i = 0; i < sk_CMS_CertificateChoices_num(org->certificates); i++) {
                CMS_CertificateChoices *cch;

                cch = sk_CMS_CertificateChoices_value(org->certificates, i);
                if (cch->type == CMS_CERTCHOICE_OTHER) {
                        env->version = 4;
                        return;
                } else if (cch->type == CMS_CERTCHOICE_V2ACERT) {
                        if (env->version < 3)
                            env->version = 3;
                }
        }

        for (i = 0; i < sk_CMS_RevocationInfoChoice_num(org->crls); i++) {
                CMS_RevocationInfoChoice *rch;

                rch = sk_CMS_RevocationInfoChoice_value(org->crls, i);
                if (rch->type == CMS_REVCHOICE_OTHER) {
                        env->version = 4;
                        return;
                }
        }
}

static void
cms_env_set_version(CMS_EnvelopedData *env)
{
        int i;
        CMS_RecipientInfo *ri;

        /*
         * Can't set version higher than 4 so if 4 or more already nothing to do.
         */
        if (env->version >= 4)
                return;

        cms_env_set_originfo_version(env);

        if (env->version >= 3)
                return;

        for (i = 0; i < sk_CMS_RecipientInfo_num(env->recipientInfos); i++) {
                ri = sk_CMS_RecipientInfo_value(env->recipientInfos, i);
                if (ri->type == CMS_RECIPINFO_PASS || ri->type == CMS_RECIPINFO_OTHER) {
                        env->version = 3;
                        return;
                } else if (ri->type != CMS_RECIPINFO_TRANS
                               || ri->d.ktri->version != 0) {
                        env->version = 2;
                }
        }
        if (env->originatorInfo || env->unprotectedAttrs)
                env->version = 2;
        if (env->version == 2)
                return;
        env->version = 0;
}

BIO *
cms_EnvelopedData_init_bio(CMS_ContentInfo *cms)
{
        CMS_EncryptedContentInfo *ec;
        STACK_OF(CMS_RecipientInfo) *rinfos;
        CMS_RecipientInfo *ri;
        int i, ok = 0;
        BIO *ret;

        /* Get BIO first to set up key */

        ec = cms->d.envelopedData->encryptedContentInfo;
        ret = cms_EncryptedContent_init_bio(ec);

        /* If error or no cipher end of processing */

        if (!ret || !ec->cipher)
                return ret;

        /* Now encrypt content key according to each RecipientInfo type */

        rinfos = cms->d.envelopedData->recipientInfos;

        for (i = 0; i < sk_CMS_RecipientInfo_num(rinfos); i++) {
                ri = sk_CMS_RecipientInfo_value(rinfos, i);
                if (CMS_RecipientInfo_encrypt(cms, ri) <= 0) {
                        CMSerror(CMS_R_ERROR_SETTING_RECIPIENTINFO);
                        goto err;
                }
        }
        cms_env_set_version(cms->d.envelopedData);

        ok = 1;

 err:
        ec->cipher = NULL;
        freezero(ec->key, ec->keylen);
        ec->key = NULL;
        ec->keylen = 0;
        if (ok)
                return ret;
        BIO_free(ret);
        return NULL;
}

/*
 * Get RecipientInfo type (if any) supported by a key (public or private). To
 * retain compatibility with previous behaviour if the ctrl value isn't
 * supported we assume key transport.
 */
int
cms_pkey_get_ri_type(EVP_PKEY *pk)
{
        if (pk->ameth && pk->ameth->pkey_ctrl) {
                int i, r;
                i = pk->ameth->pkey_ctrl(pk, ASN1_PKEY_CTRL_CMS_RI_TYPE, 0, &r);
                if (i > 0)
                        return r;
        }
        return CMS_RECIPINFO_TRANS;
}