/*
 * Copyright 2000-2021 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
 */

#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/asn1t.h>
#include <openssl/pkcs7.h>
#include <openssl/x509.h>
#include "pk7_local.h"

/* PKCS#7 ASN1 module */

/* This is the ANY DEFINED BY table for the top level PKCS#7 structure */

ASN1_ADB_TEMPLATE(p7default) = ASN1_EXP_OPT(PKCS7, d.other, ASN1_ANY, 0);

ASN1_ADB(PKCS7) = {
        ADB_ENTRY(NID_pkcs7_data, ASN1_NDEF_EXP_OPT(PKCS7, d.data, ASN1_OCTET_STRING_NDEF, 0)),
        ADB_ENTRY(NID_pkcs7_signed, ASN1_NDEF_EXP_OPT(PKCS7, d.sign, PKCS7_SIGNED, 0)),
        ADB_ENTRY(NID_pkcs7_enveloped, ASN1_NDEF_EXP_OPT(PKCS7, d.enveloped, PKCS7_ENVELOPE, 0)),
        ADB_ENTRY(NID_pkcs7_signedAndEnveloped, ASN1_NDEF_EXP_OPT(PKCS7, d.signed_and_enveloped, PKCS7_SIGN_ENVELOPE, 0)),
        ADB_ENTRY(NID_pkcs7_digest, ASN1_NDEF_EXP_OPT(PKCS7, d.digest, PKCS7_DIGEST, 0)),
        ADB_ENTRY(NID_pkcs7_encrypted, ASN1_NDEF_EXP_OPT(PKCS7, d.encrypted, PKCS7_ENCRYPT, 0))
} ASN1_ADB_END(PKCS7, 0, type, 0, &p7default_tt, NULL);

/* PKCS#7 streaming support */
static int pk7_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
                  void *exarg)
{
    ASN1_STREAM_ARG *sarg = exarg;
    PKCS7 **pp7 = (PKCS7 **)pval;

    switch (operation) {

    case ASN1_OP_STREAM_PRE:
        if (PKCS7_stream(&sarg->boundary, *pp7) <= 0)
            return 0;
        /* fall through */
    case ASN1_OP_DETACHED_PRE:
        sarg->ndef_bio = PKCS7_dataInit(*pp7, sarg->out);
        if (!sarg->ndef_bio)
            return 0;
        break;

    case ASN1_OP_STREAM_POST:
    case ASN1_OP_DETACHED_POST:
        if (PKCS7_dataFinal(*pp7, sarg->ndef_bio) <= 0)
            return 0;
        break;

    }
    return 1;
}

ASN1_NDEF_SEQUENCE_cb(PKCS7, pk7_cb) = {
        ASN1_SIMPLE(PKCS7, type, ASN1_OBJECT),
        ASN1_ADB_OBJECT(PKCS7)
}ASN1_NDEF_SEQUENCE_END_cb(PKCS7, PKCS7)

PKCS7 *d2i_PKCS7(PKCS7 **a, const unsigned char **in, long len)
{
    PKCS7 *ret;
    OSSL_LIB_CTX *libctx = NULL;
    const char *propq = NULL;

    if (a != NULL && *a != NULL) {
        libctx = (*a)->ctx.libctx;
        propq = (*a)->ctx.propq;
    }

    ret = (PKCS7 *)ASN1_item_d2i_ex((ASN1_VALUE **)a, in, len, (PKCS7_it()),
                                    libctx, propq);
    if (ret != NULL)
        ossl_pkcs7_resolve_libctx(ret);
    return ret;
}

int i2d_PKCS7(const PKCS7 *a, unsigned char **out)
{
    return ASN1_item_i2d((const ASN1_VALUE *)a, out, (PKCS7_it()));\
}

PKCS7 *PKCS7_new(void)
{
    return (PKCS7 *)ASN1_item_new(ASN1_ITEM_rptr(PKCS7));
}

PKCS7 *PKCS7_new_ex(OSSL_LIB_CTX *libctx, const char *propq)
{
    PKCS7 *pkcs7 = (PKCS7 *)ASN1_item_new_ex(ASN1_ITEM_rptr(PKCS7), libctx,
                                             propq);

    if (pkcs7 != NULL) {
        pkcs7->ctx.libctx = libctx;
        pkcs7->ctx.propq = NULL;
        if (propq != NULL) {
            pkcs7->ctx.propq = OPENSSL_strdup(propq);
            if (pkcs7->ctx.propq == NULL) {
                PKCS7_free(pkcs7);
                pkcs7 = NULL;
            }
        }
    }
    return pkcs7;
}

void PKCS7_free(PKCS7 *p7)
{
    if (p7 != NULL) {
        OPENSSL_free(p7->ctx.propq);
        ASN1_item_free((ASN1_VALUE *)p7, ASN1_ITEM_rptr(PKCS7));
    }
}

IMPLEMENT_ASN1_NDEF_FUNCTION(PKCS7)

IMPLEMENT_ASN1_DUP_FUNCTION(PKCS7)

ASN1_NDEF_SEQUENCE(PKCS7_SIGNED) = {
        ASN1_SIMPLE(PKCS7_SIGNED, version, ASN1_INTEGER),
        ASN1_SET_OF(PKCS7_SIGNED, md_algs, X509_ALGOR),
        ASN1_SIMPLE(PKCS7_SIGNED, contents, PKCS7),
        ASN1_IMP_SEQUENCE_OF_OPT(PKCS7_SIGNED, cert, X509, 0),
        ASN1_IMP_SET_OF_OPT(PKCS7_SIGNED, crl, X509_CRL, 1),
        ASN1_SET_OF(PKCS7_SIGNED, signer_info, PKCS7_SIGNER_INFO)
} ASN1_NDEF_SEQUENCE_END(PKCS7_SIGNED)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_SIGNED)

/* Minor tweak to operation: free up EVP_PKEY */
static int si_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
                 void *exarg)
{
    if (operation == ASN1_OP_FREE_POST) {
        PKCS7_SIGNER_INFO *si = (PKCS7_SIGNER_INFO *)*pval;
        EVP_PKEY_free(si->pkey);
    }
    return 1;
}

ASN1_SEQUENCE_cb(PKCS7_SIGNER_INFO, si_cb) = {
        ASN1_SIMPLE(PKCS7_SIGNER_INFO, version, ASN1_INTEGER),
        ASN1_SIMPLE(PKCS7_SIGNER_INFO, issuer_and_serial, PKCS7_ISSUER_AND_SERIAL),
        ASN1_SIMPLE(PKCS7_SIGNER_INFO, digest_alg, X509_ALGOR),
        /* NB this should be a SET OF but we use a SEQUENCE OF so the
         * original order * is retained when the structure is reencoded.
         * Since the attributes are implicitly tagged this will not affect
         * the encoding.
         */
        ASN1_IMP_SEQUENCE_OF_OPT(PKCS7_SIGNER_INFO, auth_attr, X509_ATTRIBUTE, 0),
        ASN1_SIMPLE(PKCS7_SIGNER_INFO, digest_enc_alg, X509_ALGOR),
        ASN1_SIMPLE(PKCS7_SIGNER_INFO, enc_digest, ASN1_OCTET_STRING),
        ASN1_IMP_SET_OF_OPT(PKCS7_SIGNER_INFO, unauth_attr, X509_ATTRIBUTE, 1)
} ASN1_SEQUENCE_END_cb(PKCS7_SIGNER_INFO, PKCS7_SIGNER_INFO)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_SIGNER_INFO)

ASN1_SEQUENCE(PKCS7_ISSUER_AND_SERIAL) = {
        ASN1_SIMPLE(PKCS7_ISSUER_AND_SERIAL, issuer, X509_NAME),
        ASN1_SIMPLE(PKCS7_ISSUER_AND_SERIAL, serial, ASN1_INTEGER)
} ASN1_SEQUENCE_END(PKCS7_ISSUER_AND_SERIAL)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_ISSUER_AND_SERIAL)

ASN1_NDEF_SEQUENCE(PKCS7_ENVELOPE) = {
        ASN1_SIMPLE(PKCS7_ENVELOPE, version, ASN1_INTEGER),
        ASN1_SET_OF(PKCS7_ENVELOPE, recipientinfo, PKCS7_RECIP_INFO),
        ASN1_SIMPLE(PKCS7_ENVELOPE, enc_data, PKCS7_ENC_CONTENT)
} ASN1_NDEF_SEQUENCE_END(PKCS7_ENVELOPE)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_ENVELOPE)

/* Minor tweak to operation: free up X509 */
static int ri_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
                 void *exarg)
{
    if (operation == ASN1_OP_FREE_POST) {
        PKCS7_RECIP_INFO *ri = (PKCS7_RECIP_INFO *)*pval;
        X509_free(ri->cert);
    }
    return 1;
}

ASN1_SEQUENCE_cb(PKCS7_RECIP_INFO, ri_cb) = {
        ASN1_SIMPLE(PKCS7_RECIP_INFO, version, ASN1_INTEGER),
        ASN1_SIMPLE(PKCS7_RECIP_INFO, issuer_and_serial, PKCS7_ISSUER_AND_SERIAL),
        ASN1_SIMPLE(PKCS7_RECIP_INFO, key_enc_algor, X509_ALGOR),
        ASN1_SIMPLE(PKCS7_RECIP_INFO, enc_key, ASN1_OCTET_STRING)
} ASN1_SEQUENCE_END_cb(PKCS7_RECIP_INFO, PKCS7_RECIP_INFO)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_RECIP_INFO)

ASN1_NDEF_SEQUENCE(PKCS7_ENC_CONTENT) = {
        ASN1_SIMPLE(PKCS7_ENC_CONTENT, content_type, ASN1_OBJECT),
        ASN1_SIMPLE(PKCS7_ENC_CONTENT, algorithm, X509_ALGOR),
        ASN1_IMP_OPT(PKCS7_ENC_CONTENT, enc_data, ASN1_OCTET_STRING_NDEF, 0)
} ASN1_NDEF_SEQUENCE_END(PKCS7_ENC_CONTENT)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_ENC_CONTENT)

ASN1_NDEF_SEQUENCE(PKCS7_SIGN_ENVELOPE) = {
        ASN1_SIMPLE(PKCS7_SIGN_ENVELOPE, version, ASN1_INTEGER),
        ASN1_SET_OF(PKCS7_SIGN_ENVELOPE, recipientinfo, PKCS7_RECIP_INFO),
        ASN1_SET_OF(PKCS7_SIGN_ENVELOPE, md_algs, X509_ALGOR),
        ASN1_SIMPLE(PKCS7_SIGN_ENVELOPE, enc_data, PKCS7_ENC_CONTENT),
        ASN1_IMP_SET_OF_OPT(PKCS7_SIGN_ENVELOPE, cert, X509, 0),
        ASN1_IMP_SET_OF_OPT(PKCS7_SIGN_ENVELOPE, crl, X509_CRL, 1),
        ASN1_SET_OF(PKCS7_SIGN_ENVELOPE, signer_info, PKCS7_SIGNER_INFO)
} ASN1_NDEF_SEQUENCE_END(PKCS7_SIGN_ENVELOPE)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_SIGN_ENVELOPE)

ASN1_NDEF_SEQUENCE(PKCS7_ENCRYPT) = {
        ASN1_SIMPLE(PKCS7_ENCRYPT, version, ASN1_INTEGER),
        ASN1_SIMPLE(PKCS7_ENCRYPT, enc_data, PKCS7_ENC_CONTENT)
} ASN1_NDEF_SEQUENCE_END(PKCS7_ENCRYPT)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_ENCRYPT)

ASN1_NDEF_SEQUENCE(PKCS7_DIGEST) = {
        ASN1_SIMPLE(PKCS7_DIGEST, version, ASN1_INTEGER),
        ASN1_SIMPLE(PKCS7_DIGEST, md, X509_ALGOR),
        ASN1_SIMPLE(PKCS7_DIGEST, contents, PKCS7),
        ASN1_SIMPLE(PKCS7_DIGEST, digest, ASN1_OCTET_STRING)
} ASN1_NDEF_SEQUENCE_END(PKCS7_DIGEST)

IMPLEMENT_ASN1_FUNCTIONS(PKCS7_DIGEST)

/* Specials for authenticated attributes */

/*
 * When signing attributes we want to reorder them to match the sorted
 * encoding.
 */

ASN1_ITEM_TEMPLATE(PKCS7_ATTR_SIGN) =
        ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SET_ORDER, 0, PKCS7_ATTRIBUTES, X509_ATTRIBUTE)
ASN1_ITEM_TEMPLATE_END(PKCS7_ATTR_SIGN)

/*
 * When verifying attributes we need to use the received order. So we use
 * SEQUENCE OF and tag it to SET OF
 */

ASN1_ITEM_TEMPLATE(PKCS7_ATTR_VERIFY) =
        ASN1_EX_TEMPLATE_TYPE(ASN1_TFLG_SEQUENCE_OF | ASN1_TFLG_IMPTAG | ASN1_TFLG_UNIVERSAL,
                                V_ASN1_SET, PKCS7_ATTRIBUTES, X509_ATTRIBUTE)
ASN1_ITEM_TEMPLATE_END(PKCS7_ATTR_VERIFY)

IMPLEMENT_ASN1_PRINT_FUNCTION(PKCS7)
