/* $OpenBSD: cms_sd.c,v 1.24 2022/08/28 18:27:47 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/x509.h>
#include <openssl/x509v3.h>
#include <openssl/err.h>
#include <openssl/cms.h>
#include "cms_lcl.h"
#include "asn1/asn1_locl.h"
#include "evp/evp_locl.h"

/* CMS SignedData Utilities */

static CMS_SignedData *
cms_get0_signed(CMS_ContentInfo *cms)
{
        if (OBJ_obj2nid(cms->contentType) != NID_pkcs7_signed) {
                CMSerror(CMS_R_CONTENT_TYPE_NOT_SIGNED_DATA);
                return NULL;
        }
        return cms->d.signedData;
}

static CMS_SignedData *
cms_signed_data_init(CMS_ContentInfo *cms)
{
        if (cms->d.other == NULL) {
                cms->d.signedData = (CMS_SignedData *)ASN1_item_new(&CMS_SignedData_it);
                if (!cms->d.signedData) {
                        CMSerror(ERR_R_MALLOC_FAILURE);
                        return NULL;
                }
                cms->d.signedData->version = 1;
                cms->d.signedData->encapContentInfo->eContentType =
                    OBJ_nid2obj(NID_pkcs7_data);
                cms->d.signedData->encapContentInfo->partial = 1;
                ASN1_OBJECT_free(cms->contentType);
                cms->contentType = OBJ_nid2obj(NID_pkcs7_signed);
                return cms->d.signedData;
        }
        return cms_get0_signed(cms);
}

/* Just initialise SignedData e.g. for certs only structure */

int
CMS_SignedData_init(CMS_ContentInfo *cms)
{
        if (cms_signed_data_init(cms))
                return 1;
        else
                return 0;
}

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

static void
cms_sd_set_version(CMS_SignedData *sd)
{
        int i;
        CMS_CertificateChoices *cch;
        CMS_RevocationInfoChoice *rch;
        CMS_SignerInfo *si;

        for (i = 0; i < sk_CMS_CertificateChoices_num(sd->certificates); i++) {
                cch = sk_CMS_CertificateChoices_value(sd->certificates, i);
                if (cch->type == CMS_CERTCHOICE_OTHER) {
                        if (sd->version < 5)
                            sd->version = 5;
                } else if (cch->type == CMS_CERTCHOICE_V2ACERT) {
                        if (sd->version < 4)
                            sd->version = 4;
                } else if (cch->type == CMS_CERTCHOICE_V1ACERT) {
                        if (sd->version < 3)
                            sd->version = 3;
                }
        }

        for (i = 0; i < sk_CMS_RevocationInfoChoice_num(sd->crls); i++) {
                rch = sk_CMS_RevocationInfoChoice_value(sd->crls, i);
                if (rch->type == CMS_REVCHOICE_OTHER) {
                        if (sd->version < 5)
                            sd->version = 5;
                }
        }

        if ((OBJ_obj2nid(sd->encapContentInfo->eContentType) != NID_pkcs7_data)
                && (sd->version < 3))
                sd->version = 3;

        for (i = 0; i < sk_CMS_SignerInfo_num(sd->signerInfos); i++) {
                si = sk_CMS_SignerInfo_value(sd->signerInfos, i);
                if (si->sid->type == CMS_SIGNERINFO_KEYIDENTIFIER) {
                        if (si->version < 3)
                            si->version = 3;
                        if (sd->version < 3)
                            sd->version = 3;
                } else if (si->version < 1)
                        si->version = 1;
        }

        if (sd->version < 1)
                sd->version = 1;
}

/* Copy an existing messageDigest value */

static int
cms_copy_messageDigest(CMS_ContentInfo *cms, CMS_SignerInfo *si)
{
        STACK_OF(CMS_SignerInfo) *sinfos;
        CMS_SignerInfo *sitmp;
        int i;

        sinfos = CMS_get0_SignerInfos(cms);
        for (i = 0; i < sk_CMS_SignerInfo_num(sinfos); i++) {
                ASN1_OCTET_STRING *messageDigest;
                sitmp = sk_CMS_SignerInfo_value(sinfos, i);
                if (sitmp == si)
                        continue;
                if (CMS_signed_get_attr_count(sitmp) < 0)
                        continue;
                if (OBJ_cmp(si->digestAlgorithm->algorithm,
                    sitmp->digestAlgorithm->algorithm))
                        continue;
                messageDigest = CMS_signed_get0_data_by_OBJ(sitmp,
                    OBJ_nid2obj(NID_pkcs9_messageDigest), -3, V_ASN1_OCTET_STRING);
                if (!messageDigest) {
                        CMSerror(CMS_R_ERROR_READING_MESSAGEDIGEST_ATTRIBUTE);
                        return 0;
                }

                if (CMS_signed_add1_attr_by_NID(si, NID_pkcs9_messageDigest,
                    V_ASN1_OCTET_STRING, messageDigest, -1))
                        return 1;
                else
                        return 0;
        }

        CMSerror(CMS_R_NO_MATCHING_DIGEST);

        return 0;
}

int
cms_set1_SignerIdentifier(CMS_SignerIdentifier *sid, X509 *cert, int type)
{
        switch (type) {
        case CMS_SIGNERINFO_ISSUER_SERIAL:
                if (!cms_set1_ias(&sid->d.issuerAndSerialNumber, cert))
                        return 0;
                break;

        case CMS_SIGNERINFO_KEYIDENTIFIER:
                if (!cms_set1_keyid(&sid->d.subjectKeyIdentifier, cert))
                        return 0;
                break;

        default:
                CMSerror(CMS_R_UNKNOWN_ID);
                return 0;
        }

        sid->type = type;

        return 1;
}

int
cms_SignerIdentifier_get0_signer_id(CMS_SignerIdentifier *sid,
    ASN1_OCTET_STRING **keyid, X509_NAME **issuer, ASN1_INTEGER **sno)
{
        if (sid->type == CMS_SIGNERINFO_ISSUER_SERIAL) {
                if (issuer)
                        *issuer = sid->d.issuerAndSerialNumber->issuer;
                if (sno)
                        *sno = sid->d.issuerAndSerialNumber->serialNumber;
        } else if (sid->type == CMS_SIGNERINFO_KEYIDENTIFIER) {
                if (keyid)
                        *keyid = sid->d.subjectKeyIdentifier;
        } else
                return 0;

        return 1;
}

int
cms_SignerIdentifier_cert_cmp(CMS_SignerIdentifier *sid, X509 *cert)
{
        if (sid->type == CMS_SIGNERINFO_ISSUER_SERIAL)
                return cms_ias_cert_cmp(sid->d.issuerAndSerialNumber, cert);
        else if (sid->type == CMS_SIGNERINFO_KEYIDENTIFIER)
                return cms_keyid_cert_cmp(sid->d.subjectKeyIdentifier, cert);
        else
                return -1;
}

static int
cms_sd_asn1_ctrl(CMS_SignerInfo *si, int cmd)
{
        EVP_PKEY *pkey = si->pkey;
        int i;

        if (!pkey->ameth || !pkey->ameth->pkey_ctrl)
                return 1;
        i = pkey->ameth->pkey_ctrl(pkey, ASN1_PKEY_CTRL_CMS_SIGN, cmd, si);
        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;
}

CMS_SignerInfo *
CMS_add1_signer(CMS_ContentInfo *cms, X509 *signer, EVP_PKEY *pk,
    const EVP_MD *md, unsigned int flags)
{
        CMS_SignedData *sd;
        CMS_SignerInfo *si = NULL;
        X509_ALGOR *alg;
        int i, type;

        if (!X509_check_private_key(signer, pk)) {
                CMSerror(CMS_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
                return NULL;
        }
        sd = cms_signed_data_init(cms);
        if (!sd)
                goto err;
        si = (CMS_SignerInfo *)ASN1_item_new(&CMS_SignerInfo_it);
        if (!si)
                goto merr;
        /* Call for side-effect of computing hash and caching extensions */
        X509_check_purpose(signer, -1, -1);

        X509_up_ref(signer);
        EVP_PKEY_up_ref(pk);

        si->pkey = pk;
        si->signer = signer;
        si->mctx = EVP_MD_CTX_new();
        si->pctx = NULL;

        if (si->mctx == NULL) {
                CMSerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        if (flags & CMS_USE_KEYID) {
                si->version = 3;
                if (sd->version < 3)
                        sd->version = 3;
                type = CMS_SIGNERINFO_KEYIDENTIFIER;
        } else {
                type = CMS_SIGNERINFO_ISSUER_SERIAL;
                si->version = 1;
        }

        if (!cms_set1_SignerIdentifier(si->sid, signer, type))
                goto err;

        if (md == NULL) {
                int def_nid;
                if (EVP_PKEY_get_default_digest_nid(pk, &def_nid) <= 0)
                        goto err;
                md = EVP_get_digestbynid(def_nid);
                if (md == NULL) {
                        CMSerror(CMS_R_NO_DEFAULT_DIGEST);
                        goto err;
                }
        }

        if (!md) {
                CMSerror(CMS_R_NO_DIGEST_SET);
                goto err;
        }

        X509_ALGOR_set_md(si->digestAlgorithm, md);

        /* See if digest is present in digestAlgorithms */
        for (i = 0; i < sk_X509_ALGOR_num(sd->digestAlgorithms); i++) {
                const ASN1_OBJECT *aoid;
                alg = sk_X509_ALGOR_value(sd->digestAlgorithms, i);
                X509_ALGOR_get0(&aoid, NULL, NULL, alg);
                if (OBJ_obj2nid(aoid) == EVP_MD_type(md))
                        break;
        }

        if (i == sk_X509_ALGOR_num(sd->digestAlgorithms)) {
                alg = X509_ALGOR_new();
                if (alg == NULL)
                        goto merr;
                X509_ALGOR_set_md(alg, md);
                if (!sk_X509_ALGOR_push(sd->digestAlgorithms, alg)) {
                        X509_ALGOR_free(alg);
                        goto merr;
                }
        }

        if (!(flags & CMS_KEY_PARAM) && !cms_sd_asn1_ctrl(si, 0))
                goto err;
        if (!(flags & CMS_NOATTR)) {
                /*
                 * Initialize signed attributes structure so other attributes
                 * such as signing time etc are added later even if we add none here.
                 */
                if (!si->signedAttrs) {
                        si->signedAttrs = sk_X509_ATTRIBUTE_new_null();
                        if (!si->signedAttrs)
                                goto merr;
                }

                if (!(flags & CMS_NOSMIMECAP)) {
                        STACK_OF(X509_ALGOR) *smcap = NULL;

                        i = CMS_add_standard_smimecap(&smcap);
                        if (i)
                            i = CMS_add_smimecap(si, smcap);
                        sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free);
                        if (!i)
                                goto merr;
                }
                if (flags & CMS_REUSE_DIGEST) {
                        if (!cms_copy_messageDigest(cms, si))
                                goto err;
                        if (!(flags & (CMS_PARTIAL | CMS_KEY_PARAM)) &&
                            !CMS_SignerInfo_sign(si))
                                goto err;
                }
        }

        if (!(flags & CMS_NOCERTS)) {
                /* NB ignore -1 return for duplicate cert */
                if (!CMS_add1_cert(cms, signer))
                        goto merr;
        }

        if (flags & CMS_KEY_PARAM) {
                if (flags & CMS_NOATTR) {
                        si->pctx = EVP_PKEY_CTX_new(si->pkey, NULL);
                        if (si->pctx == NULL)
                                goto err;
                        if (EVP_PKEY_sign_init(si->pctx) <= 0)
                                goto err;
                        if (EVP_PKEY_CTX_set_signature_md(si->pctx, md) <= 0)
                                goto err;
                } else if (EVP_DigestSignInit(si->mctx, &si->pctx, md,
                    NULL, pk) <= 0)
                        goto err;
        }

        if (!sd->signerInfos)
                sd->signerInfos = sk_CMS_SignerInfo_new_null();
        if (!sd->signerInfos || !sk_CMS_SignerInfo_push(sd->signerInfos, si))
                goto merr;

        return si;

 merr:
        CMSerror(ERR_R_MALLOC_FAILURE);
 err:
        ASN1_item_free((ASN1_VALUE *)si, &CMS_SignerInfo_it);

        return NULL;
}

static int
cms_add1_signingTime(CMS_SignerInfo *si, ASN1_TIME *t)
{
        ASN1_TIME *tt;
        int r = 0;

        if (t)
                tt = t;
        else
                tt = X509_gmtime_adj(NULL, 0);

        if (!tt)
                goto merr;

        if (CMS_signed_add1_attr_by_NID(si, NID_pkcs9_signingTime,
                                                tt->type, tt, -1) <= 0)
                goto merr;

        r = 1;

 merr:
        if (!t)
                ASN1_TIME_free(tt);
        if (!r)
                CMSerror(ERR_R_MALLOC_FAILURE);

        return r;
}

EVP_PKEY_CTX *
CMS_SignerInfo_get0_pkey_ctx(CMS_SignerInfo *si)
{
        return si->pctx;
}

EVP_MD_CTX *
CMS_SignerInfo_get0_md_ctx(CMS_SignerInfo *si)
{
        return si->mctx;
}

STACK_OF(CMS_SignerInfo) *
CMS_get0_SignerInfos(CMS_ContentInfo *cms)
{
        CMS_SignedData *sd;

        sd = cms_get0_signed(cms);
        if (!sd)
                return NULL;

        return sd->signerInfos;
}

STACK_OF(X509) *
CMS_get0_signers(CMS_ContentInfo *cms)
{
        STACK_OF(X509) *signers = NULL;
        STACK_OF(CMS_SignerInfo) *sinfos;
        CMS_SignerInfo *si;
        int i;

        sinfos = CMS_get0_SignerInfos(cms);
        for (i = 0; i < sk_CMS_SignerInfo_num(sinfos); i++) {
                si = sk_CMS_SignerInfo_value(sinfos, i);
                if (si->signer) {
                        if (!signers) {
                                signers = sk_X509_new_null();
                                if (!signers)
                                        return NULL;
                        }
                        if (!sk_X509_push(signers, si->signer)) {
                                sk_X509_free(signers);
                                return NULL;
                        }
                }
        }

        return signers;
}

void
CMS_SignerInfo_set1_signer_cert(CMS_SignerInfo *si, X509 *signer)
{
        if (signer) {
                X509_up_ref(signer);
                EVP_PKEY_free(si->pkey);
                si->pkey = X509_get_pubkey(signer);
        }
        X509_free(si->signer);
        si->signer = signer;
}

int
CMS_SignerInfo_get0_signer_id(CMS_SignerInfo *si, ASN1_OCTET_STRING **keyid,
    X509_NAME **issuer, ASN1_INTEGER **sno)
{
        return cms_SignerIdentifier_get0_signer_id(si->sid, keyid, issuer, sno);
}

int
CMS_SignerInfo_cert_cmp(CMS_SignerInfo *si, X509 *cert)
{
        return cms_SignerIdentifier_cert_cmp(si->sid, cert);
}

int
CMS_set1_signers_certs(CMS_ContentInfo *cms, STACK_OF(X509) *scerts,
    unsigned int flags)
{
        CMS_SignedData *sd;
        CMS_SignerInfo *si;
        CMS_CertificateChoices *cch;
        STACK_OF(CMS_CertificateChoices) *certs;
        X509 *x;
        int i, j;
        int ret = 0;

        sd = cms_get0_signed(cms);
        if (!sd)
                return -1;
        certs = sd->certificates;
        for (i = 0; i < sk_CMS_SignerInfo_num(sd->signerInfos); i++) {
                si = sk_CMS_SignerInfo_value(sd->signerInfos, i);
                if (si->signer)
                        continue;

                for (j = 0; j < sk_X509_num(scerts); j++) {
                        x = sk_X509_value(scerts, j);
                        if (CMS_SignerInfo_cert_cmp(si, x) == 0) {
                                CMS_SignerInfo_set1_signer_cert(si, x);
                                ret++;
                                break;
                        }
                }

                if (si->signer || (flags & CMS_NOINTERN))
                        continue;

                for (j = 0; j < sk_CMS_CertificateChoices_num(certs); j++) {
                        cch = sk_CMS_CertificateChoices_value(certs, j);
                        if (cch->type != 0)
                                continue;
                        x = cch->d.certificate;
                        if (CMS_SignerInfo_cert_cmp(si, x) == 0) {
                                CMS_SignerInfo_set1_signer_cert(si, x);
                                ret++;
                                break;
                        }
                }
        }
        return ret;
}

void
CMS_SignerInfo_get0_algs(CMS_SignerInfo *si, EVP_PKEY **pk, X509 **signer,
X509_ALGOR **pdig, X509_ALGOR **psig)
{
        if (pk)
                *pk = si->pkey;
        if (signer)
                *signer = si->signer;
        if (pdig)
                *pdig = si->digestAlgorithm;
        if (psig)
                *psig = si->signatureAlgorithm;
}

ASN1_OCTET_STRING *
CMS_SignerInfo_get0_signature(CMS_SignerInfo *si)
{
        return si->signature;
}

static int
cms_SignerInfo_content_sign(CMS_ContentInfo *cms, CMS_SignerInfo *si, BIO *chain)
{
        EVP_MD_CTX *mctx = EVP_MD_CTX_new();
        int r = 0;
        EVP_PKEY_CTX *pctx = NULL;

        if (mctx == NULL) {
                CMSerror(ERR_R_MALLOC_FAILURE);
                return 0;
        }

        if (!si->pkey) {
                CMSerror(CMS_R_NO_PRIVATE_KEY);
                goto err;
        }

        if (!cms_DigestAlgorithm_find_ctx(mctx, chain, si->digestAlgorithm))
                goto err;
        /* Set SignerInfo algorithm details if we used custom parameter */
        if (si->pctx && !cms_sd_asn1_ctrl(si, 0))
                goto err;

        /*
         * If any signed attributes calculate and add messageDigest attribute
         */

        if (CMS_signed_get_attr_count(si) >= 0) {
                ASN1_OBJECT *ctype =
                    cms->d.signedData->encapContentInfo->eContentType;
                unsigned char md[EVP_MAX_MD_SIZE];
                unsigned int mdlen;

                if (!EVP_DigestFinal_ex(mctx, md, &mdlen))
                        goto err;
                if (!CMS_signed_add1_attr_by_NID(si, NID_pkcs9_messageDigest,
                    V_ASN1_OCTET_STRING, md, mdlen))
                        goto err;
                /* Copy content type across */
                if (CMS_signed_add1_attr_by_NID(si, NID_pkcs9_contentType,
                    V_ASN1_OBJECT, ctype, -1) <= 0)
                        goto err;
                if (!CMS_SignerInfo_sign(si))
                        goto err;
        } else if (si->pctx) {
                unsigned char *sig;
                size_t siglen;
                unsigned char md[EVP_MAX_MD_SIZE];
                unsigned int mdlen;

                pctx = si->pctx;
                if (!EVP_DigestFinal_ex(mctx, md, &mdlen))
                        goto err;
                siglen = EVP_PKEY_size(si->pkey);
                sig = malloc(siglen);
                if (sig == NULL) {
                        CMSerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                if (EVP_PKEY_sign(pctx, sig, &siglen, md, mdlen) <= 0) {
                        free(sig);
                        goto err;
                }
                ASN1_STRING_set0(si->signature, sig, siglen);
        } else {
                unsigned char *sig;
                unsigned int siglen;

                sig = malloc(EVP_PKEY_size(si->pkey));
                if (sig == NULL) {
                        CMSerror(ERR_R_MALLOC_FAILURE);
                        goto err;
                }
                if (!EVP_SignFinal(mctx, sig, &siglen, si->pkey)) {
                        CMSerror(CMS_R_SIGNFINAL_ERROR);
                        free(sig);
                        goto err;
                }
                ASN1_STRING_set0(si->signature, sig, siglen);
        }

        r = 1;

 err:
        EVP_MD_CTX_free(mctx);
        EVP_PKEY_CTX_free(pctx);

        return r;
}

int
cms_SignedData_final(CMS_ContentInfo *cms, BIO *chain)
{
        STACK_OF(CMS_SignerInfo) *sinfos;
        CMS_SignerInfo *si;
        int i;

        sinfos = CMS_get0_SignerInfos(cms);
        for (i = 0; i < sk_CMS_SignerInfo_num(sinfos); i++) {
                si = sk_CMS_SignerInfo_value(sinfos, i);
                if (!cms_SignerInfo_content_sign(cms, si, chain))
                        return 0;
        }
        cms->d.signedData->encapContentInfo->partial = 0;

        return 1;
}

int
CMS_SignerInfo_sign(CMS_SignerInfo *si)
{
        EVP_MD_CTX *mctx = si->mctx;
        EVP_PKEY_CTX *pctx = NULL;
        unsigned char *abuf = NULL;
        int alen;
        size_t siglen;
        const EVP_MD *md = NULL;

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

        if (CMS_signed_get_attr_by_NID(si, NID_pkcs9_signingTime, -1) < 0) {
                if (!cms_add1_signingTime(si, NULL))
                        goto err;
        }

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

        if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
            EVP_PKEY_CTRL_CMS_SIGN, 0, si) <= 0) {
                CMSerror(CMS_R_CTRL_ERROR);
                goto err;
        }

        alen = ASN1_item_i2d((ASN1_VALUE *)si->signedAttrs, &abuf,
            &CMS_Attributes_Sign_it);
        if (!abuf)
                goto err;
        if (EVP_DigestSignUpdate(mctx, abuf, alen) <= 0)
                goto err;
        if (EVP_DigestSignFinal(mctx, NULL, &siglen) <= 0)
                goto err;
        free(abuf);
        abuf = malloc(siglen);
        if (abuf == NULL)
                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_CMS_SIGN, 1, si) <= 0) {
                CMSerror(CMS_R_CTRL_ERROR);
                goto err;
        }

        EVP_MD_CTX_reset(mctx);

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

        return 1;

 err:
        free(abuf);
        EVP_MD_CTX_reset(mctx);

        return 0;
}

int
CMS_SignerInfo_verify(CMS_SignerInfo *si)
{
        EVP_MD_CTX *mctx = NULL;
        unsigned char *abuf = NULL;
        int alen, r = -1;
        const EVP_MD *md = NULL;

        if (!si->pkey) {
                CMSerror(CMS_R_NO_PUBLIC_KEY);
                return -1;
        }

        md = EVP_get_digestbyobj(si->digestAlgorithm->algorithm);
        if (md == NULL)
                return -1;
        if (si->mctx == NULL && (si->mctx = EVP_MD_CTX_new()) == NULL) {
                CMSerror(ERR_R_MALLOC_FAILURE);
                return -1;
        }
        mctx = si->mctx;
        if (EVP_DigestVerifyInit(mctx, &si->pctx, md, NULL, si->pkey) <= 0)
                goto err;

        if (!cms_sd_asn1_ctrl(si, 1))
                goto err;

        alen = ASN1_item_i2d((ASN1_VALUE *)si->signedAttrs, &abuf,
            &CMS_Attributes_Verify_it);
        if (!abuf)
                goto err;
        r = EVP_DigestVerifyUpdate(mctx, abuf, alen);
        free(abuf);
        if (r <= 0) {
                r = -1;
                goto err;
        }

        r = EVP_DigestVerifyFinal(mctx, si->signature->data,
            si->signature->length);
        if (r <= 0)
                CMSerror(CMS_R_VERIFICATION_FAILURE);

 err:
        EVP_MD_CTX_reset(mctx);

        return r;
}

/* Create a chain of digest BIOs from a CMS ContentInfo */

BIO *
cms_SignedData_init_bio(CMS_ContentInfo *cms)
{
        int i;
        CMS_SignedData *sd;
        BIO *chain = NULL;

        sd = cms_get0_signed(cms);
        if (!sd)
                return NULL;
        if (cms->d.signedData->encapContentInfo->partial)
                cms_sd_set_version(sd);
        for (i = 0; i < sk_X509_ALGOR_num(sd->digestAlgorithms); i++) {
                X509_ALGOR *digestAlgorithm;
                BIO *mdbio;
                digestAlgorithm = sk_X509_ALGOR_value(sd->digestAlgorithms, i);
                mdbio = cms_DigestAlgorithm_init_bio(digestAlgorithm);
                if (!mdbio)
                        goto err;
                if (chain)
                        BIO_push(chain, mdbio);
                else
                        chain = mdbio;
        }

        return chain;

 err:
        BIO_free_all(chain);

        return NULL;
}

int
CMS_SignerInfo_verify_content(CMS_SignerInfo *si, BIO *chain)
{
        ASN1_OCTET_STRING *os = NULL;
        EVP_MD_CTX *mctx = EVP_MD_CTX_new();
        EVP_PKEY_CTX *pkctx = NULL;
        int r = -1;
        unsigned char mval[EVP_MAX_MD_SIZE];
        unsigned int mlen;

        if (mctx == NULL) {
                CMSerror(ERR_R_MALLOC_FAILURE);
                goto err;
        }
        /* If we have any signed attributes look for messageDigest value */
        if (CMS_signed_get_attr_count(si) >= 0) {
                os = CMS_signed_get0_data_by_OBJ(si,
                    OBJ_nid2obj(NID_pkcs9_messageDigest), -3,
                    V_ASN1_OCTET_STRING);
                if (!os) {
                        CMSerror(CMS_R_ERROR_READING_MESSAGEDIGEST_ATTRIBUTE);
                        goto err;
                }
        }

        if (!cms_DigestAlgorithm_find_ctx(mctx, chain, si->digestAlgorithm))
                goto err;

        if (EVP_DigestFinal_ex(mctx, mval, &mlen) <= 0) {
                CMSerror(CMS_R_UNABLE_TO_FINALIZE_CONTEXT);
                goto err;
        }

        /* If messageDigest found compare it */

        if (os) {
                if (mlen != (unsigned int)os->length) {
                        CMSerror(CMS_R_MESSAGEDIGEST_ATTRIBUTE_WRONG_LENGTH);
                        goto err;
                }

                if (memcmp(mval, os->data, mlen)) {
                        CMSerror(CMS_R_VERIFICATION_FAILURE);
                        r = 0;
                } else
                        r = 1;
        } else {
                const EVP_MD *md = EVP_MD_CTX_md(mctx);

                pkctx = EVP_PKEY_CTX_new(si->pkey, NULL);
                if (pkctx == NULL)
                        goto err;
                if (EVP_PKEY_verify_init(pkctx) <= 0)
                        goto err;
                if (EVP_PKEY_CTX_set_signature_md(pkctx, md) <= 0)
                        goto err;
                si->pctx = pkctx;
                if (!cms_sd_asn1_ctrl(si, 1))
                        goto err;
                r = EVP_PKEY_verify(pkctx, si->signature->data,
                                        si->signature->length, mval, mlen);
                if (r <= 0) {
                        CMSerror(CMS_R_VERIFICATION_FAILURE);
                        r = 0;
                }
        }

 err:
        EVP_PKEY_CTX_free(pkctx);
        EVP_MD_CTX_free(mctx);

        return r;
}

int
CMS_add_smimecap(CMS_SignerInfo *si, STACK_OF(X509_ALGOR) *algs)
{
        unsigned char *smder = NULL;
        int smderlen, r;

        smderlen = i2d_X509_ALGORS(algs, &smder);
        if (smderlen <= 0)
                return 0;
        r = CMS_signed_add1_attr_by_NID(si, NID_SMIMECapabilities,
            V_ASN1_SEQUENCE, smder, smderlen);
        free(smder);

        return r;
}

int
CMS_add_simple_smimecap(STACK_OF(X509_ALGOR) **algs, int algnid, int keysize)
{
        X509_ALGOR *alg;
        ASN1_INTEGER *key = NULL;

        if (keysize > 0) {
                if ((key = ASN1_INTEGER_new()) == NULL)
                        return 0;
                if (!ASN1_INTEGER_set(key, keysize)) {
                        ASN1_INTEGER_free(key);
                        return 0;
                }
        }
        alg = X509_ALGOR_new();
        if (alg == NULL) {
                ASN1_INTEGER_free(key);
                return 0;
        }

        X509_ALGOR_set0(alg, OBJ_nid2obj(algnid),
            key ? V_ASN1_INTEGER : V_ASN1_UNDEF, key);
        if (*algs == NULL)
                *algs = sk_X509_ALGOR_new_null();
        if (*algs == NULL || !sk_X509_ALGOR_push(*algs, alg)) {
                X509_ALGOR_free(alg);
                return 0;
        }

        return 1;
}

/* Check to see if a cipher exists and if so add S/MIME capabilities */

static int
cms_add_cipher_smcap(STACK_OF(X509_ALGOR) **sk, int nid, int arg)
{
        if (EVP_get_cipherbynid(nid))
                return CMS_add_simple_smimecap(sk, nid, arg);
        return 1;
}

static int
cms_add_digest_smcap(STACK_OF(X509_ALGOR) **sk, int nid, int arg)
{
        if (EVP_get_digestbynid(nid))
                return CMS_add_simple_smimecap(sk, nid, arg);
        return 1;
}

int
CMS_add_standard_smimecap(STACK_OF(X509_ALGOR) **smcap)
{
        if (!cms_add_cipher_smcap(smcap, NID_aes_256_cbc, -1) ||
            !cms_add_digest_smcap(smcap, NID_id_GostR3411_94, -1) ||
            !cms_add_cipher_smcap(smcap, NID_id_Gost28147_89, -1) ||
            !cms_add_cipher_smcap(smcap, NID_aes_192_cbc, -1) ||
            !cms_add_cipher_smcap(smcap, NID_aes_128_cbc, -1) ||
            !cms_add_cipher_smcap(smcap, NID_des_ede3_cbc, -1) ||
            !cms_add_cipher_smcap(smcap, NID_rc2_cbc, 128) ||
            !cms_add_cipher_smcap(smcap, NID_rc2_cbc, 64) ||
            !cms_add_cipher_smcap(smcap, NID_des_cbc, -1) ||
            !cms_add_cipher_smcap(smcap, NID_rc2_cbc, 40))
                return 0;

        return 1;
}