/*

 * Copyright 2008-2016 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 "internal/cryptlib.h"

#include <openssl/asn1t.h>

#include <openssl/pem.h>

#include <openssl/rand.h>

#include <openssl/x509v3.h>

#include <openssl/err.h>

#include <openssl/cms.h>

#include "cms_local.h"

IMPLEMENT_ASN1_FUNCTIONS(CMS_ReceiptRequest)

/* ESS services: for now just Signed Receipt related */

int CMS_get1_ReceiptRequest(CMS_SignerInfo *si, CMS_ReceiptRequest **prr)

{

    ASN1_STRING *str;

    CMS_ReceiptRequest *rr = NULL;

    if (prr)

        *prr = NULL;

    str = CMS_signed_get0_data_by_OBJ(si,

                                      OBJ_nid2obj

                                      (NID_id_smime_aa_receiptRequest), -3,

                                      V_ASN1_SEQUENCE);

    if (!str)

        return 0;

    rr = ASN1_item_unpack(str, ASN1_ITEM_rptr(CMS_ReceiptRequest));

    if (!rr)

        return -1;

    if (prr)

        *prr = rr;

    else

        CMS_ReceiptRequest_free(rr);

    return 1;

}

CMS_ReceiptRequest *CMS_ReceiptRequest_create0(unsigned char *id, int idlen,

                                               int allorfirst,

                                               STACK_OF(GENERAL_NAMES)

                                               *receiptList, STACK_OF(GENERAL_NAMES)

                                               *receiptsTo)

{

    CMS_ReceiptRequest *rr = NULL;

    rr = CMS_ReceiptRequest_new();

    if (rr == NULL)

        goto merr;

    if (id)

        ASN1_STRING_set0(rr->signedContentIdentifier, id, idlen);

    else {

        if (!ASN1_STRING_set(rr->signedContentIdentifier, NULL, 32))

            goto merr;

        if (RAND_bytes(rr->signedContentIdentifier->data, 32) <= 0)

            goto err;

    }

    sk_GENERAL_NAMES_pop_free(rr->receiptsTo, GENERAL_NAMES_free);

    rr->receiptsTo = receiptsTo;

    if (receiptList) {

        rr->receiptsFrom->type = 1;

        rr->receiptsFrom->d.receiptList = receiptList;

    } else {

        rr->receiptsFrom->type = 0;

        rr->receiptsFrom->d.allOrFirstTier = allorfirst;

    }

    return rr;

 merr:

    CMSerr(CMS_F_CMS_RECEIPTREQUEST_CREATE0, ERR_R_MALLOC_FAILURE);

 err:

    CMS_ReceiptRequest_free(rr);

    return NULL;

}

int CMS_add1_ReceiptRequest(CMS_SignerInfo *si, CMS_ReceiptRequest *rr)

{

    unsigned char *rrder = NULL;

    int rrderlen, r = 0;

    rrderlen = i2d_CMS_ReceiptRequest(rr, &rrder);

    if (rrderlen < 0)

        goto merr;

    if (!CMS_signed_add1_attr_by_NID(si, NID_id_smime_aa_receiptRequest,

                                     V_ASN1_SEQUENCE, rrder, rrderlen))

        goto merr;

    r = 1;

 merr:

    if (!r)

        CMSerr(CMS_F_CMS_ADD1_RECEIPTREQUEST, ERR_R_MALLOC_FAILURE);

    OPENSSL_free(rrder);

    return r;

}

void CMS_ReceiptRequest_get0_values(CMS_ReceiptRequest *rr,

                                    ASN1_STRING **pcid,

                                    int *pallorfirst,

                                    STACK_OF(GENERAL_NAMES) **plist,

                                    STACK_OF(GENERAL_NAMES) **prto)

{

    if (pcid)

        *pcid = rr->signedContentIdentifier;

    if (rr->receiptsFrom->type == 0) {

        if (pallorfirst)

            *pallorfirst = (int)rr->receiptsFrom->d.allOrFirstTier;

        if (plist)

            *plist = NULL;

    } else {

        if (pallorfirst)

            *pallorfirst = -1;

        if (plist)

            *plist = rr->receiptsFrom->d.receiptList;

    }

    if (prto)

        *prto = rr->receiptsTo;

}

/* Digest a SignerInfo structure for msgSigDigest attribute processing */

static int cms_msgSigDigest(CMS_SignerInfo *si,

                            unsigned char *dig, unsigned int *diglen)

{

    const EVP_MD *md;

    md = EVP_get_digestbyobj(si->digestAlgorithm->algorithm);

    if (md == NULL)

        return 0;

    if (!ASN1_item_digest(ASN1_ITEM_rptr(CMS_Attributes_Verify), md,

                          si->signedAttrs, dig, diglen))

        return 0;

    return 1;

}

/* Add a msgSigDigest attribute to a SignerInfo */

int cms_msgSigDigest_add1(CMS_SignerInfo *dest, CMS_SignerInfo *src)

{

    unsigned char dig[EVP_MAX_MD_SIZE];

    unsigned int diglen;

    if (!cms_msgSigDigest(src, dig, &diglen)) {

        CMSerr(CMS_F_CMS_MSGSIGDIGEST_ADD1, CMS_R_MSGSIGDIGEST_ERROR);

        return 0;

    }

    if (!CMS_signed_add1_attr_by_NID(dest, NID_id_smime_aa_msgSigDigest,

                                     V_ASN1_OCTET_STRING, dig, diglen)) {

        CMSerr(CMS_F_CMS_MSGSIGDIGEST_ADD1, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    return 1;

}

/* Verify signed receipt after it has already passed normal CMS verify */

int cms_Receipt_verify(CMS_ContentInfo *cms, CMS_ContentInfo *req_cms)

{

    int r = 0, i;

    CMS_ReceiptRequest *rr = NULL;

    CMS_Receipt *rct = NULL;

    STACK_OF(CMS_SignerInfo) *sis, *osis;

    CMS_SignerInfo *si, *osi = NULL;

    ASN1_OCTET_STRING *msig, **pcont;

    ASN1_OBJECT *octype;

    unsigned char dig[EVP_MAX_MD_SIZE];

    unsigned int diglen;

    /* Get SignerInfos, also checks SignedData content type */

    osis = CMS_get0_SignerInfos(req_cms);

    sis = CMS_get0_SignerInfos(cms);

    if (!osis || !sis)

        goto err;

    if (sk_CMS_SignerInfo_num(sis) != 1) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_NEED_ONE_SIGNER);

        goto err;

    }

    /* Check receipt content type */

    if (OBJ_obj2nid(CMS_get0_eContentType(cms)) != NID_id_smime_ct_receipt) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_NOT_A_SIGNED_RECEIPT);

        goto err;

    }

    /* Extract and decode receipt content */

    pcont = CMS_get0_content(cms);

    if (!pcont || !*pcont) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_NO_CONTENT);

        goto err;

    }

    rct = ASN1_item_unpack(*pcont, ASN1_ITEM_rptr(CMS_Receipt));

    if (!rct) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_RECEIPT_DECODE_ERROR);

        goto err;

    }

    /* Locate original request */

    for (i = 0; i < sk_CMS_SignerInfo_num(osis); i++) {

        osi = sk_CMS_SignerInfo_value(osis, i);

        if (!ASN1_STRING_cmp(osi->signature, rct->originatorSignatureValue))

            break;

    }

    if (i == sk_CMS_SignerInfo_num(osis)) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_NO_MATCHING_SIGNATURE);

        goto err;

    }

    si = sk_CMS_SignerInfo_value(sis, 0);

    /* Get msgSigDigest value and compare */

    msig = CMS_signed_get0_data_by_OBJ(si,

                                       OBJ_nid2obj

                                       (NID_id_smime_aa_msgSigDigest), -3,

                                       V_ASN1_OCTET_STRING);

    if (!msig) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_NO_MSGSIGDIGEST);

        goto err;

    }

    if (!cms_msgSigDigest(osi, dig, &diglen)) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_MSGSIGDIGEST_ERROR);

        goto err;

    }

    if (diglen != (unsigned int)msig->length) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_MSGSIGDIGEST_WRONG_LENGTH);

        goto err;

    }

    if (memcmp(dig, msig->data, diglen)) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY,

               CMS_R_MSGSIGDIGEST_VERIFICATION_FAILURE);

        goto err;

    }

    /* Compare content types */

    octype = CMS_signed_get0_data_by_OBJ(osi,

                                         OBJ_nid2obj(NID_pkcs9_contentType),

                                         -3, V_ASN1_OBJECT);

    if (!octype) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_NO_CONTENT_TYPE);

        goto err;

    }

    /* Compare details in receipt request */

    if (OBJ_cmp(octype, rct->contentType)) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_CONTENT_TYPE_MISMATCH);

        goto err;

    }

    /* Get original receipt request details */

    if (CMS_get1_ReceiptRequest(osi, &rr) <= 0) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_NO_RECEIPT_REQUEST);

        goto err;

    }

    if (ASN1_STRING_cmp(rr->signedContentIdentifier,

                        rct->signedContentIdentifier)) {

        CMSerr(CMS_F_CMS_RECEIPT_VERIFY, CMS_R_CONTENTIDENTIFIER_MISMATCH);

        goto err;

    }

    r = 1;

 err:

    CMS_ReceiptRequest_free(rr);

    M_ASN1_free_of(rct, CMS_Receipt);

    return r;

}

/*

 * Encode a Receipt into an OCTET STRING read for including into content of a

 * SignedData ContentInfo.

 */

ASN1_OCTET_STRING *cms_encode_Receipt(CMS_SignerInfo *si)

{

    CMS_Receipt rct;

    CMS_ReceiptRequest *rr = NULL;

    ASN1_OBJECT *ctype;

    ASN1_OCTET_STRING *os = NULL;

    /* Get original receipt request */

    /* Get original receipt request details */

    if (CMS_get1_ReceiptRequest(si, &rr) <= 0) {

        CMSerr(CMS_F_CMS_ENCODE_RECEIPT, CMS_R_NO_RECEIPT_REQUEST);

        goto err;

    }

    /* Get original content type */

    ctype = CMS_signed_get0_data_by_OBJ(si,

                                        OBJ_nid2obj(NID_pkcs9_contentType),

                                        -3, V_ASN1_OBJECT);

    if (!ctype) {

        CMSerr(CMS_F_CMS_ENCODE_RECEIPT, CMS_R_NO_CONTENT_TYPE);

        goto err;

    }

    rct.version = 1;

    rct.contentType = ctype;

    rct.signedContentIdentifier = rr->signedContentIdentifier;

    rct.originatorSignatureValue = si->signature;

    os = ASN1_item_pack(&rct, ASN1_ITEM_rptr(CMS_Receipt), NULL);

 err:

    CMS_ReceiptRequest_free(rr);

    return os;

}