/* $OpenBSD: pk7_doit.c,v 1.61 2025/07/27 07:06:41 tb Exp $ */
/* 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 <stdlib.h>
#include <string.h>

#include <openssl/objects.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>

#include "err_local.h"
#include "evp_local.h"
#include "x509_local.h"

static int
PKCS7_type_is_other(PKCS7* p7)
{
        int isOther = 1;

        int nid = OBJ_obj2nid(p7->type);

        switch (nid ) {
        case NID_pkcs7_data:
        case NID_pkcs7_signed:
        case NID_pkcs7_enveloped:
        case NID_pkcs7_signedAndEnveloped:
        case NID_pkcs7_digest:
        case NID_pkcs7_encrypted:
                isOther = 0;
                break;
        default:
                isOther = 1;
        }

        return isOther;

}

ASN1_OCTET_STRING *
PKCS7_get_octet_string(PKCS7 *p7)
{
        if (PKCS7_type_is_data(p7))
                return p7->d.data;
        if (PKCS7_type_is_other(p7) && p7->d.other &&
            (p7->d.other->type == V_ASN1_OCTET_STRING))
                return p7->d.other->value.octet_string;
        return NULL;
}

static int
PKCS7_bio_add_digest(BIO **pbio, X509_ALGOR *alg)
{
        BIO *btmp;
        const EVP_MD *md;

        if ((btmp = BIO_new(BIO_f_md())) == NULL) {
                PKCS7error(ERR_R_BIO_LIB);
                goto err;
        }

        md = EVP_get_digestbyobj(alg->algorithm);
        if (md == NULL) {
                PKCS7error(PKCS7_R_UNKNOWN_DIGEST_TYPE);
                goto err;
        }

        if (BIO_set_md(btmp, md) <= 0) {
                PKCS7error(ERR_R_BIO_LIB);
                goto err;
        }

        if (*pbio == NULL)
                *pbio = btmp;
        else if (!BIO_push(*pbio, btmp)) {
                PKCS7error(ERR_R_BIO_LIB);
                goto err;
        }
        btmp = NULL;

        return 1;

err:
        BIO_free(btmp);
        return 0;

}

static int
pkcs7_encode_rinfo(PKCS7_RECIP_INFO *ri, unsigned char *key, int keylen)
{
        EVP_PKEY_CTX *pctx = NULL;
        EVP_PKEY *pkey = NULL;
        unsigned char *ek = NULL;
        int ret = 0;
        size_t eklen;

        pkey = X509_get_pubkey(ri->cert);
        if (!pkey)
                return 0;

        pctx = EVP_PKEY_CTX_new(pkey, NULL);
        if (!pctx)
                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_PKCS7_ENCRYPT, 0, ri) <= 0) {
                PKCS7error(PKCS7_R_CTRL_ERROR);
                goto err;
        }

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

        ek = malloc(eklen);

        if (ek == NULL) {
                PKCS7error(ERR_R_MALLOC_FAILURE);
                goto err;
        }

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

        ASN1_STRING_set0(ri->enc_key, ek, eklen);
        ek = NULL;

        ret = 1;

err:
        EVP_PKEY_free(pkey);
        EVP_PKEY_CTX_free(pctx);
        free(ek);
        return ret;
}


static int
pkcs7_decrypt_rinfo(unsigned char **pek, int *peklen, PKCS7_RECIP_INFO *ri,
    EVP_PKEY *pkey, size_t fixlen)
{
        EVP_PKEY_CTX *pctx = NULL;
        unsigned char *ek = NULL;
        size_t eklen;

        int ret = -1;

        pctx = EVP_PKEY_CTX_new(pkey, NULL);
        if (!pctx)
                return -1;

        if (EVP_PKEY_decrypt_init(pctx) <= 0)
                goto err;

        if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_DECRYPT,
            EVP_PKEY_CTRL_PKCS7_DECRYPT, 0, ri) <= 0) {
                PKCS7error(PKCS7_R_CTRL_ERROR);
                goto err;
        }

        if (EVP_PKEY_decrypt(pctx, NULL, &eklen,
            ri->enc_key->data, ri->enc_key->length) <= 0)
                goto err;

        ek = malloc(eklen);
        if (ek == NULL) {
                PKCS7error(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        if (EVP_PKEY_decrypt(pctx, ek, &eklen, ri->enc_key->data,
            ri->enc_key->length) <= 0 || eklen == 0 ||
            (fixlen != 0 && eklen != fixlen)) {
                ret = 0;
                PKCS7error(ERR_R_EVP_LIB);
                goto err;
        }

        ret = 1;

        freezero(*pek, *peklen);

        *pek = ek;
        *peklen = eklen;

err:
        EVP_PKEY_CTX_free(pctx);
        if (!ret && ek)
                free(ek);

        return ret;
}

BIO *
PKCS7_dataInit(PKCS7 *p7, BIO *bio)
{
        int i;
        BIO *out = NULL, *btmp = NULL;
        X509_ALGOR *xa = NULL;
        const EVP_CIPHER *evp_cipher = NULL;
        STACK_OF(X509_ALGOR) *md_sk = NULL;
        STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
        X509_ALGOR *xalg = NULL;
        PKCS7_RECIP_INFO *ri = NULL;
        ASN1_OCTET_STRING *os = NULL;

        if (p7 == NULL) {
                PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
                return NULL;
        }

        /*
         * The content field in the PKCS7 ContentInfo is optional,
         * but that really only applies to inner content (precisely,
         * detached signatures).
         *
         * When reading content, missing outer content is therefore
         * treated as an error.
         *
         * When creating content, PKCS7_content_new() must be called
         * before calling this method, so a NULL p7->d is always
         * an error.
         */
        if (p7->d.ptr == NULL) {
                PKCS7error(PKCS7_R_NO_CONTENT);
                return NULL;
        }

        i = OBJ_obj2nid(p7->type);
        p7->state = PKCS7_S_HEADER;

        switch (i) {
        case NID_pkcs7_signed:
                md_sk = p7->d.sign->md_algs;
                os = PKCS7_get_octet_string(p7->d.sign->contents);
                break;
        case NID_pkcs7_signedAndEnveloped:
                rsk = p7->d.signed_and_enveloped->recipientinfo;
                md_sk = p7->d.signed_and_enveloped->md_algs;
                xalg = p7->d.signed_and_enveloped->enc_data->algorithm;
                evp_cipher = p7->d.signed_and_enveloped->enc_data->cipher;
                if (evp_cipher == NULL) {
                        PKCS7error(PKCS7_R_CIPHER_NOT_INITIALIZED);
                        goto err;
                }
                break;
        case NID_pkcs7_enveloped:
                rsk = p7->d.enveloped->recipientinfo;
                xalg = p7->d.enveloped->enc_data->algorithm;
                evp_cipher = p7->d.enveloped->enc_data->cipher;
                if (evp_cipher == NULL) {
                        PKCS7error(PKCS7_R_CIPHER_NOT_INITIALIZED);
                        goto err;
                }
                break;
        case NID_pkcs7_digest:
                xa = p7->d.digest->md;
                os = PKCS7_get_octet_string(p7->d.digest->contents);
                break;
        case NID_pkcs7_data:
                break;
        default:
                PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
                goto err;
        }

        for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++)
                if (!PKCS7_bio_add_digest(&out, sk_X509_ALGOR_value(md_sk, i)))
                        goto err;

        if (xa && !PKCS7_bio_add_digest(&out, xa))
                goto err;

        if (evp_cipher != NULL) {
                unsigned char key[EVP_MAX_KEY_LENGTH];
                unsigned char iv[EVP_MAX_IV_LENGTH];
                int keylen, ivlen;
                EVP_CIPHER_CTX *ctx;

                if ((btmp = BIO_new(BIO_f_cipher())) == NULL) {
                        PKCS7error(ERR_R_BIO_LIB);
                        goto err;
                }
                BIO_get_cipher_ctx(btmp, &ctx);
                keylen = EVP_CIPHER_key_length(evp_cipher);
                ivlen = EVP_CIPHER_iv_length(evp_cipher);
                xalg->algorithm = OBJ_nid2obj(EVP_CIPHER_type(evp_cipher));
                if (ivlen > 0)
                        arc4random_buf(iv, ivlen);
                if (EVP_CipherInit_ex(ctx, evp_cipher, NULL, NULL,
                    NULL, 1) <= 0)
                        goto err;
                if (EVP_CIPHER_CTX_rand_key(ctx, key) <= 0)
                        goto err;
                if (EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, 1) <= 0)
                        goto err;

                if (ivlen > 0) {
                        if (xalg->parameter == NULL) {
                                xalg->parameter = ASN1_TYPE_new();
                                if (xalg->parameter == NULL)
                                        goto err;
                        }
                        if (EVP_CIPHER_param_to_asn1(ctx, xalg->parameter) < 0)
                                goto err;
                }

                /* Lets do the pub key stuff :-) */
                for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
                        ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
                        if (pkcs7_encode_rinfo(ri, key, keylen) <= 0)
                                goto err;
                }
                explicit_bzero(key, keylen);

                if (out == NULL)
                        out = btmp;
                else
                        BIO_push(out, btmp);
                btmp = NULL;
        }

        if (bio == NULL) {
                if (PKCS7_is_detached(p7))
                        bio = BIO_new(BIO_s_null());
                else if (os && os->length > 0)
                        bio = BIO_new_mem_buf(os->data, os->length);
                if (bio == NULL) {
                        bio = BIO_new(BIO_s_mem());
                        if (bio == NULL)
                                goto err;
                        BIO_set_mem_eof_return(bio, 0);
                }
        }
        if (out)
                BIO_push(out, bio);
        else
                out = bio;
        bio = NULL;
        if (0) {
err:
                if (out != NULL)
                        BIO_free_all(out);
                if (btmp != NULL)
                        BIO_free_all(btmp);
                out = NULL;
        }
        return out;
}
LCRYPTO_ALIAS(PKCS7_dataInit);

static int
pkcs7_cmp_ri(PKCS7_RECIP_INFO *ri, X509 *pcert)
{
        int ret;

        ret = X509_NAME_cmp(ri->issuer_and_serial->issuer,
            pcert->cert_info->issuer);
        if (ret)
                return ret;
        return ASN1_INTEGER_cmp(pcert->cert_info->serialNumber,
            ri->issuer_and_serial->serial);
}

/* int */
BIO *
PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
{
        int i, j;
        BIO *out = NULL, *btmp = NULL, *etmp = NULL, *bio = NULL;
        X509_ALGOR *xa;
        ASN1_OCTET_STRING *data_body = NULL;
        const EVP_MD *evp_md;
        const EVP_CIPHER *evp_cipher = NULL;
        EVP_CIPHER_CTX *evp_ctx = NULL;
        X509_ALGOR *enc_alg = NULL;
        STACK_OF(X509_ALGOR) *md_sk = NULL;
        STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
        PKCS7_RECIP_INFO *ri = NULL;
        unsigned char *ek = NULL, *tkey = NULL;
        int eklen = 0, tkeylen = 0;

        if (p7 == NULL) {
                PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
                return NULL;
        }

        if (p7->d.ptr == NULL) {
                PKCS7error(PKCS7_R_NO_CONTENT);
                return NULL;
        }

        i = OBJ_obj2nid(p7->type);
        p7->state = PKCS7_S_HEADER;

        switch (i) {
        case NID_pkcs7_signed:
                data_body = PKCS7_get_octet_string(p7->d.sign->contents);
                md_sk = p7->d.sign->md_algs;
                break;
        case NID_pkcs7_signedAndEnveloped:
                rsk = p7->d.signed_and_enveloped->recipientinfo;
                md_sk = p7->d.signed_and_enveloped->md_algs;
                data_body = p7->d.signed_and_enveloped->enc_data->enc_data;
                enc_alg = p7->d.signed_and_enveloped->enc_data->algorithm;
                evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
                if (evp_cipher == NULL) {
                        PKCS7error(PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
                        goto err;
                }
                break;
        case NID_pkcs7_enveloped:
                rsk = p7->d.enveloped->recipientinfo;
                enc_alg = p7->d.enveloped->enc_data->algorithm;
                data_body = p7->d.enveloped->enc_data->enc_data;
                evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
                if (evp_cipher == NULL) {
                        PKCS7error(PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
                        goto err;
                }
                break;
        default:
                PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
                goto err;
        }

        /* We will be checking the signature */
        if (md_sk != NULL) {
                for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++) {
                        xa = sk_X509_ALGOR_value(md_sk, i);
                        if ((btmp = BIO_new(BIO_f_md())) == NULL) {
                                PKCS7error(ERR_R_BIO_LIB);
                                goto err;
                        }

                        j = OBJ_obj2nid(xa->algorithm);
                        evp_md = EVP_get_digestbynid(j);
                        if (evp_md == NULL) {
                                PKCS7error(PKCS7_R_UNKNOWN_DIGEST_TYPE);
                                goto err;
                        }

                        if (BIO_set_md(btmp, evp_md) <= 0) {
                                PKCS7error(ERR_R_BIO_LIB);
                                goto err;
                        }
                        if (out == NULL)
                                out = btmp;
                        else
                                BIO_push(out, btmp);
                        btmp = NULL;
                }
        }

        if (evp_cipher != NULL) {
                if ((etmp = BIO_new(BIO_f_cipher())) == NULL) {
                        PKCS7error(ERR_R_BIO_LIB);
                        goto err;
                }

                /* It was encrypted, we need to decrypt the secret key
                 * with the private key */

                /* Find the recipientInfo which matches the passed certificate
                 * (if any)
                 */
                if (pcert) {
                        for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
                                ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
                                if (!pkcs7_cmp_ri(ri, pcert))
                                        break;
                                ri = NULL;
                        }
                        if (ri == NULL) {
                                PKCS7error(PKCS7_R_NO_RECIPIENT_MATCHES_CERTIFICATE);
                                goto err;
                        }
                }

                /* If we haven't got a certificate try each ri in turn */
                if (pcert == NULL) {
                        /* Always attempt to decrypt all rinfo even
                         * after success as a defence against MMA timing
                         * attacks.
                         */
                        for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
                                ri = sk_PKCS7_RECIP_INFO_value(rsk, i);

                                if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey,
                                    EVP_CIPHER_key_length(evp_cipher)) < 0)
                                        goto err;
                                ERR_clear_error();
                        }
                } else {
                        /* Only exit on fatal errors, not decrypt failure */
                        if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey, 0) < 0)
                                goto err;
                        ERR_clear_error();
                }

                evp_ctx = NULL;
                BIO_get_cipher_ctx(etmp, &evp_ctx);
                if (EVP_CipherInit_ex(evp_ctx, evp_cipher, NULL, NULL,
                    NULL, 0) <= 0)
                        goto err;
                if (EVP_CIPHER_asn1_to_param(evp_ctx, enc_alg->parameter) < 0)
                        goto err;
                /* Generate random key as MMA defence */
                tkeylen = EVP_CIPHER_CTX_key_length(evp_ctx);
                tkey = malloc(tkeylen);
                if (!tkey)
                        goto err;
                if (EVP_CIPHER_CTX_rand_key(evp_ctx, tkey) <= 0)
                        goto err;
                if (ek == NULL) {
                        ek = tkey;
                        eklen = tkeylen;
                        tkey = NULL;
                }

                if (eklen != EVP_CIPHER_CTX_key_length(evp_ctx)) {
                        /* Some S/MIME clients don't use the same key
                         * and effective key length. The key length is
                         * determined by the size of the decrypted RSA key.
                         */
                        if (!EVP_CIPHER_CTX_set_key_length(evp_ctx, eklen)) {
                                /* Use random key as MMA defence */
                                freezero(ek, eklen);
                                ek = tkey;
                                eklen = tkeylen;
                                tkey = NULL;
                        }
                }
                /* Clear errors so we don't leak information useful in MMA */
                ERR_clear_error();
                if (EVP_CipherInit_ex(evp_ctx, NULL, NULL, ek, NULL, 0) <= 0)
                        goto err;

                freezero(ek, eklen);
                ek = NULL;
                freezero(tkey, tkeylen);
                tkey = NULL;

                if (out == NULL)
                        out = etmp;
                else
                        BIO_push(out, etmp);
                etmp = NULL;
        }

        if (PKCS7_is_detached(p7) || (in_bio != NULL)) {
                bio = in_bio;
        } else {
                if (data_body != NULL && data_body->length > 0)
                        bio = BIO_new_mem_buf(data_body->data, data_body->length);
                else {
                        bio = BIO_new(BIO_s_mem());
                        BIO_set_mem_eof_return(bio, 0);
                }
                if (bio == NULL)
                        goto err;
        }
        BIO_push(out, bio);

        if (0) {
err:
                freezero(ek, eklen);
                freezero(tkey, tkeylen);
                if (out != NULL)
                        BIO_free_all(out);
                if (btmp != NULL)
                        BIO_free_all(btmp);
                if (etmp != NULL)
                        BIO_free_all(etmp);
                out = NULL;
        }
        return out;
}
LCRYPTO_ALIAS(PKCS7_dataDecode);

static BIO *
PKCS7_find_digest(EVP_MD_CTX **pmd, BIO *bio, int nid)
{
        for (;;) {
                bio = BIO_find_type(bio, BIO_TYPE_MD);
                if (bio == NULL) {
                        PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
                        return NULL;
                }
                BIO_get_md_ctx(bio, pmd);
                if (*pmd == NULL) {
                        PKCS7error(ERR_R_INTERNAL_ERROR);
                        return NULL;
                }
                if (EVP_MD_CTX_type(*pmd) == nid)
                        return bio;
                bio = BIO_next(bio);
        }
        return NULL;
}

static int
do_pkcs7_signed_attrib(PKCS7_SIGNER_INFO *si, EVP_MD_CTX *mctx)
{
        unsigned char md_data[EVP_MAX_MD_SIZE];
        unsigned int md_len;

        /* Add signing time if not already present */
        if (!PKCS7_get_signed_attribute(si, NID_pkcs9_signingTime)) {
                if (!PKCS7_add0_attrib_signing_time(si, NULL)) {
                        PKCS7error(ERR_R_MALLOC_FAILURE);
                        return 0;
                }
        }

        /* Add digest */
        if (!EVP_DigestFinal_ex(mctx, md_data, &md_len)) {
                PKCS7error(ERR_R_EVP_LIB);
                return 0;
        }
        if (!PKCS7_add1_attrib_digest(si, md_data, md_len)) {
                PKCS7error(ERR_R_MALLOC_FAILURE);
                return 0;
        }

        /* Now sign the attributes */
        if (!PKCS7_SIGNER_INFO_sign(si))
                return 0;

        return 1;
}


int
PKCS7_dataFinal(PKCS7 *p7, BIO *bio)
{
        int ret = 0;
        int i, j;
        BIO *btmp;
        PKCS7_SIGNER_INFO *si;
        EVP_MD_CTX *mdc, ctx_tmp;
        STACK_OF(X509_ATTRIBUTE) *sk;
        STACK_OF(PKCS7_SIGNER_INFO) *si_sk = NULL;
        ASN1_OCTET_STRING *os = NULL;

        if (p7 == NULL) {
                PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
                return 0;
        }

        if (p7->d.ptr == NULL) {
                PKCS7error(PKCS7_R_NO_CONTENT);
                return 0;
        }

        EVP_MD_CTX_legacy_clear(&ctx_tmp);
        i = OBJ_obj2nid(p7->type);
        p7->state = PKCS7_S_HEADER;

        switch (i) {
        case NID_pkcs7_data:
                os = p7->d.data;
                break;
        case NID_pkcs7_signedAndEnveloped:
                /* XXX */
                si_sk = p7->d.signed_and_enveloped->signer_info;
                os = p7->d.signed_and_enveloped->enc_data->enc_data;
                if (!os) {
                        os = ASN1_OCTET_STRING_new();
                        if (!os) {
                                PKCS7error(ERR_R_MALLOC_FAILURE);
                                goto err;
                        }
                        p7->d.signed_and_enveloped->enc_data->enc_data = os;
                }
                break;
        case NID_pkcs7_enveloped:
                /* XXX */
                os = p7->d.enveloped->enc_data->enc_data;
                if (!os) {
                        os = ASN1_OCTET_STRING_new();
                        if (!os) {
                                PKCS7error(ERR_R_MALLOC_FAILURE);
                                goto err;
                        }
                        p7->d.enveloped->enc_data->enc_data = os;
                }
                break;
        case NID_pkcs7_signed:
                si_sk = p7->d.sign->signer_info;
                os = PKCS7_get_octet_string(p7->d.sign->contents);
                if (!PKCS7_is_detached(p7) && os == NULL) {
                        PKCS7error(PKCS7_R_DECODE_ERROR);
                        goto err;
                }
                /* If detached data then the content is excluded */
                if (PKCS7_type_is_data(p7->d.sign->contents) && p7->detached) {
                        ASN1_OCTET_STRING_free(os);
                        os = NULL;
                        p7->d.sign->contents->d.data = NULL;
                }
                break;

        case NID_pkcs7_digest:
                os = PKCS7_get_octet_string(p7->d.digest->contents);
                if (os == NULL) {
                        PKCS7error(PKCS7_R_DECODE_ERROR);
                        goto err;
                }
                /* If detached data then the content is excluded */
                if (PKCS7_type_is_data(p7->d.digest->contents) &&
                    p7->detached) {
                        ASN1_OCTET_STRING_free(os);
                        os = NULL;
                        p7->d.digest->contents->d.data = NULL;
                }
                break;

        default:
                PKCS7error(PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
                goto err;
        }

        if (si_sk != NULL) {
                for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(si_sk); i++) {
                        si = sk_PKCS7_SIGNER_INFO_value(si_sk, i);
                        if (si->pkey == NULL)
                                continue;

                        j = OBJ_obj2nid(si->digest_alg->algorithm);

                        if ((btmp = PKCS7_find_digest(&mdc, bio, j)) == NULL)
                                goto err;

                        /* We now have the EVP_MD_CTX, lets do the
                         * signing. */
                        if (!EVP_MD_CTX_copy_ex(&ctx_tmp, mdc))
                                goto err;

                        sk = si->auth_attr;

                        /* If there are attributes, we add the digest
                         * attribute and only sign the attributes */
                        if (sk_X509_ATTRIBUTE_num(sk) > 0) {
                                if (!do_pkcs7_signed_attrib(si, &ctx_tmp))
                                        goto err;
                        } else {
                                unsigned char *abuf = NULL;
                                unsigned int abuflen;
                                abuflen = EVP_PKEY_size(si->pkey);
                                abuf = malloc(abuflen);
                                if (!abuf)
                                        goto err;

                                if (!EVP_SignFinal(&ctx_tmp, abuf, &abuflen,
                                    si->pkey)) {
                                        PKCS7error(ERR_R_EVP_LIB);
                                        free(abuf);
                                        goto err;
                                }
                                ASN1_STRING_set0(si->enc_digest, abuf, abuflen);
                        }
                }
        } else if (i == NID_pkcs7_digest) {
                unsigned char md_data[EVP_MAX_MD_SIZE];
                unsigned int md_len;

                if (!PKCS7_find_digest(&mdc, bio,
                    OBJ_obj2nid(p7->d.digest->md->algorithm)))
                        goto err;
                if (!EVP_DigestFinal_ex(mdc, md_data, &md_len))
                        goto err;
                if (ASN1_STRING_set(p7->d.digest->digest, md_data,
                    md_len) == 0)
                        goto err;
        }

        if (!PKCS7_is_detached(p7)) {
                /*
                 * NOTE: only reach os == NULL here because detached
                 * digested data support is broken?
                 */
                if (os == NULL)
                        goto err;
                if (!(os->flags & ASN1_STRING_FLAG_NDEF)) {
                        char *cont;
                        long contlen;

                        btmp = BIO_find_type(bio, BIO_TYPE_MEM);
                        if (btmp == NULL) {
                                PKCS7error(PKCS7_R_UNABLE_TO_FIND_MEM_BIO);
                                goto err;
                        }
                        contlen = BIO_get_mem_data(btmp, &cont);
                        /*
                         * Mark the BIO read only then we can use its copy
                         * of the data instead of making an extra copy.
                         */
                        BIO_set_flags(btmp, BIO_FLAGS_MEM_RDONLY);
                        BIO_set_mem_eof_return(btmp, 0);
                        ASN1_STRING_set0(os, (unsigned char *)cont, contlen);
                }
        }
        ret = 1;
err:
        EVP_MD_CTX_cleanup(&ctx_tmp);
        return ret;
}
LCRYPTO_ALIAS(PKCS7_dataFinal);

int
PKCS7_SIGNER_INFO_sign(PKCS7_SIGNER_INFO *si)
{
        EVP_MD_CTX mctx;
        EVP_PKEY_CTX *pctx;
        unsigned char *abuf = NULL;
        int alen;
        size_t siglen;
        const EVP_MD *md = NULL;

        md = EVP_get_digestbyobj(si->digest_alg->algorithm);
        if (md == NULL)
                return 0;

        EVP_MD_CTX_legacy_clear(&mctx);
        if (EVP_DigestSignInit(&mctx, &pctx, md, NULL, si->pkey) <= 0)
                goto err;

        if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
            EVP_PKEY_CTRL_PKCS7_SIGN, 0, si) <= 0) {
                PKCS7error(PKCS7_R_CTRL_ERROR);
                goto err;
        }

        alen = ASN1_item_i2d((ASN1_VALUE *)si->auth_attr, &abuf,
            &PKCS7_ATTR_SIGN_it);
        if (!abuf)
                goto err;
        if (EVP_DigestSignUpdate(&mctx, abuf, alen) <= 0)
                goto err;
        free(abuf);
        abuf = NULL;
        if (EVP_DigestSignFinal(&mctx, NULL, &siglen) <= 0)
                goto err;
        abuf = malloc(siglen);
        if (!abuf)
                goto err;
        if (EVP_DigestSignFinal(&mctx, abuf, &siglen) <= 0)
                goto err;

        if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
            EVP_PKEY_CTRL_PKCS7_SIGN, 1, si) <= 0) {
                PKCS7error(PKCS7_R_CTRL_ERROR);
                goto err;
        }

        EVP_MD_CTX_cleanup(&mctx);

        ASN1_STRING_set0(si->enc_digest, abuf, siglen);

        return 1;

err:
        free(abuf);
        EVP_MD_CTX_cleanup(&mctx);
        return 0;
}
LCRYPTO_ALIAS(PKCS7_SIGNER_INFO_sign);

int
PKCS7_dataVerify(X509_STORE *cert_store, X509_STORE_CTX *ctx, BIO *bio,
    PKCS7 *p7, PKCS7_SIGNER_INFO *si)
{
        PKCS7_ISSUER_AND_SERIAL *ias;
        int ret = 0, i;
        STACK_OF(X509) *cert;
        X509 *x509;

        if (p7 == NULL) {
                PKCS7error(PKCS7_R_INVALID_NULL_POINTER);
                return 0;
        }

        if (p7->d.ptr == NULL) {
                PKCS7error(PKCS7_R_NO_CONTENT);
                return 0;
        }

        if (PKCS7_type_is_signed(p7)) {
                cert = p7->d.sign->cert;
        } else if (PKCS7_type_is_signedAndEnveloped(p7)) {
                cert = p7->d.signed_and_enveloped->cert;
        } else {
                PKCS7error(PKCS7_R_WRONG_PKCS7_TYPE);
                goto err;
        }
        /* XXXX */
        ias = si->issuer_and_serial;

        x509 = X509_find_by_issuer_and_serial(cert, ias->issuer, ias->serial);

        /* were we able to find the cert in passed to us */
        if (x509 == NULL) {
                PKCS7error(PKCS7_R_UNABLE_TO_FIND_CERTIFICATE);
                goto err;
        }

        /* Lets verify */
        if (!X509_STORE_CTX_init(ctx, cert_store, x509, cert)) {
                PKCS7error(ERR_R_X509_LIB);
                goto err;
        }
        if (X509_STORE_CTX_set_purpose(ctx, X509_PURPOSE_SMIME_SIGN) == 0) {
                X509_STORE_CTX_cleanup(ctx);
                goto err;
        }
        i = X509_verify_cert(ctx);
        if (i <= 0) {
                PKCS7error(ERR_R_X509_LIB);
                X509_STORE_CTX_cleanup(ctx);
                goto err;
        }
        X509_STORE_CTX_cleanup(ctx);

        return PKCS7_signatureVerify(bio, p7, si, x509);

err:
        return ret;
}
LCRYPTO_ALIAS(PKCS7_dataVerify);

int
PKCS7_signatureVerify(BIO *bio, PKCS7 *p7, PKCS7_SIGNER_INFO *si, X509 *x509)
{
        ASN1_OCTET_STRING *os;
        EVP_MD_CTX mdc_tmp, *mdc;
        int ret = 0, i;
        int md_type;
        STACK_OF(X509_ATTRIBUTE) *sk;
        BIO *btmp;
        EVP_PKEY *pkey;

        EVP_MD_CTX_legacy_clear(&mdc_tmp);

        if (!PKCS7_type_is_signed(p7) &&
            !PKCS7_type_is_signedAndEnveloped(p7)) {
                PKCS7error(PKCS7_R_WRONG_PKCS7_TYPE);
                goto err;
        }

        md_type = OBJ_obj2nid(si->digest_alg->algorithm);

        btmp = bio;
        for (;;) {
                if ((btmp == NULL) ||
                    ((btmp = BIO_find_type(btmp, BIO_TYPE_MD)) == NULL)) {
                        PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
                        goto err;
                }
                BIO_get_md_ctx(btmp, &mdc);
                if (mdc == NULL) {
                        PKCS7error(ERR_R_INTERNAL_ERROR);
                        goto err;
                }
                if (EVP_MD_CTX_type(mdc) == md_type)
                        break;
                /* Workaround for some broken clients that put the signature
                 * OID instead of the digest OID in digest_alg->algorithm
                 */
                if (EVP_MD_pkey_type(EVP_MD_CTX_md(mdc)) == md_type)
                        break;
                btmp = BIO_next(btmp);
        }

        /* mdc is the digest ctx that we want, unless there are attributes,
         * in which case the digest is the signed attributes */
        if (!EVP_MD_CTX_copy_ex(&mdc_tmp, mdc))
                goto err;

        sk = si->auth_attr;
        if ((sk != NULL) && (sk_X509_ATTRIBUTE_num(sk) != 0)) {
                unsigned char md_dat[EVP_MAX_MD_SIZE], *abuf = NULL;
                unsigned int md_len;
                int alen;
                ASN1_OCTET_STRING *message_digest;

                if (!EVP_DigestFinal_ex(&mdc_tmp, md_dat, &md_len))
                        goto err;
                message_digest = PKCS7_digest_from_attributes(sk);
                if (!message_digest) {
                        PKCS7error(PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
                        goto err;
                }
                if ((message_digest->length != (int)md_len) ||
                    (memcmp(message_digest->data, md_dat, md_len))) {
                        PKCS7error(PKCS7_R_DIGEST_FAILURE);
                        ret = -1;
                        goto err;
                }

                if (!EVP_VerifyInit_ex(&mdc_tmp, EVP_get_digestbynid(md_type),
                    NULL))
                        goto err;

                alen = ASN1_item_i2d((ASN1_VALUE *)sk, &abuf,
                    &PKCS7_ATTR_VERIFY_it);
                if (alen <= 0) {
                        PKCS7error(ERR_R_ASN1_LIB);
                        ret = -1;
                        goto err;
                }
                if (!EVP_VerifyUpdate(&mdc_tmp, abuf, alen)) {
                        free(abuf);
                        goto err;
                }

                free(abuf);
        }

        os = si->enc_digest;
        pkey = X509_get_pubkey(x509);
        if (!pkey) {
                ret = -1;
                goto err;
        }

        i = EVP_VerifyFinal(&mdc_tmp, os->data, os->length, pkey);
        EVP_PKEY_free(pkey);
        if (i <= 0) {
                PKCS7error(PKCS7_R_SIGNATURE_FAILURE);
                ret = -1;
                goto err;
        } else
                ret = 1;
err:
        EVP_MD_CTX_cleanup(&mdc_tmp);
        return ret;
}
LCRYPTO_ALIAS(PKCS7_signatureVerify);

PKCS7_ISSUER_AND_SERIAL *
PKCS7_get_issuer_and_serial(PKCS7 *p7, int idx)
{
        STACK_OF(PKCS7_RECIP_INFO) *rsk;
        PKCS7_RECIP_INFO *ri;
        int i;

        i = OBJ_obj2nid(p7->type);
        if (i != NID_pkcs7_signedAndEnveloped)
                return NULL;
        if (p7->d.signed_and_enveloped == NULL)
                return NULL;
        rsk = p7->d.signed_and_enveloped->recipientinfo;
        if (rsk == NULL)
                return NULL;
        ri = sk_PKCS7_RECIP_INFO_value(rsk, 0);
        if (sk_PKCS7_RECIP_INFO_num(rsk) <= idx)
                return NULL;
        ri = sk_PKCS7_RECIP_INFO_value(rsk, idx);
        return ri->issuer_and_serial;
}
LCRYPTO_ALIAS(PKCS7_get_issuer_and_serial);

static ASN1_TYPE *
get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid)
{
        int i;
        X509_ATTRIBUTE *xa;
        ASN1_OBJECT *o;

        o = OBJ_nid2obj(nid);
        if (!o || !sk)
                return NULL;
        for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
                xa = sk_X509_ATTRIBUTE_value(sk, i);
                if (OBJ_cmp(xa->object, o) == 0)
                        return sk_ASN1_TYPE_value(xa->set, 0);
        }
        return NULL;
}

ASN1_TYPE *
PKCS7_get_signed_attribute(PKCS7_SIGNER_INFO *si, int nid)
{
        return get_attribute(si->auth_attr, nid);
}
LCRYPTO_ALIAS(PKCS7_get_signed_attribute);

ASN1_TYPE *
PKCS7_get_attribute(PKCS7_SIGNER_INFO *si, int nid)
{
        return get_attribute(si->unauth_attr, nid);
}
LCRYPTO_ALIAS(PKCS7_get_attribute);

ASN1_OCTET_STRING *
PKCS7_digest_from_attributes(STACK_OF(X509_ATTRIBUTE) *sk)
{
        ASN1_TYPE *astype;

        if (!(astype = get_attribute(sk, NID_pkcs9_messageDigest)))
                return NULL;
        if (astype->type != V_ASN1_OCTET_STRING)
                return NULL;
        return astype->value.octet_string;
}
LCRYPTO_ALIAS(PKCS7_digest_from_attributes);

int
PKCS7_set_signed_attributes(PKCS7_SIGNER_INFO *p7si,
    STACK_OF(X509_ATTRIBUTE) *sk)
{
        int i;

        if (p7si->auth_attr != NULL)
                sk_X509_ATTRIBUTE_pop_free(p7si->auth_attr,
                    X509_ATTRIBUTE_free);
        p7si->auth_attr = sk_X509_ATTRIBUTE_dup(sk);
        if (p7si->auth_attr == NULL)
                return 0;
        for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
                if ((sk_X509_ATTRIBUTE_set(p7si->auth_attr, i,
                    X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value(sk, i))))
                    == NULL)
                        return 0;
        }
        return 1;
}
LCRYPTO_ALIAS(PKCS7_set_signed_attributes);

int
PKCS7_set_attributes(PKCS7_SIGNER_INFO *p7si, STACK_OF(X509_ATTRIBUTE) *sk)
{
        int i;

        if (p7si->unauth_attr != NULL)
                sk_X509_ATTRIBUTE_pop_free(p7si->unauth_attr,
                    X509_ATTRIBUTE_free);
        p7si->unauth_attr = sk_X509_ATTRIBUTE_dup(sk);
        if (p7si->unauth_attr == NULL)
                return 0;
        for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
                if ((sk_X509_ATTRIBUTE_set(p7si->unauth_attr, i,
                    X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value(sk, i))))
                    == NULL)
                        return 0;
        }
        return 1;
}
LCRYPTO_ALIAS(PKCS7_set_attributes);

static int
add_attribute(STACK_OF(X509_ATTRIBUTE) **in_sk, int nid, int atrtype, void *value)
{
        STACK_OF(X509_ATTRIBUTE) *sk;
        X509_ATTRIBUTE *old_attr = NULL, *new_attr = NULL;
        int need_pop = 0;
        int i;

        if ((sk = *in_sk) == NULL)
                sk = sk_X509_ATTRIBUTE_new_null();
        if (sk == NULL)
                goto err;

        /* Replace an already existing attribute with the given nid. */
        for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
                old_attr = sk_X509_ATTRIBUTE_value(sk, i);
                if(OBJ_obj2nid(old_attr->object) == nid)
                        break;
        }

        /* If there is none, make room for the new one, so _set() succeeds. */
        if (i == sk_X509_ATTRIBUTE_num(sk)) {
                old_attr = NULL;
                if (sk_X509_ATTRIBUTE_push(sk, NULL) <= 0)
                        goto err;
                need_pop = 1;
        }

        /* On success, new_attr owns value. */
        if ((new_attr = X509_ATTRIBUTE_create(nid, atrtype, value)) == NULL)
                goto err;

        X509_ATTRIBUTE_free(old_attr);
        (void)sk_X509_ATTRIBUTE_set(sk, i, new_attr);

        *in_sk = sk;

        return 1;

 err:
        if (need_pop)
                (void)sk_X509_ATTRIBUTE_pop(sk);
        if (*in_sk != sk)
                sk_X509_ATTRIBUTE_pop_free(sk, X509_ATTRIBUTE_free);

        return 0;
}

int
PKCS7_add_signed_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype,
    void *value)
{
        return add_attribute(&(p7si->auth_attr), nid, atrtype, value);
}
LCRYPTO_ALIAS(PKCS7_add_signed_attribute);

int
PKCS7_add_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype, void *value)
{
        return add_attribute(&(p7si->unauth_attr), nid, atrtype, value);
}
LCRYPTO_ALIAS(PKCS7_add_attribute);