hx509: Remove unused variable

[heimdal.git] / lib / hx509 / cms.c

/*
 * Copyright (c) 2003 - 2007 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * 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. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE 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.
 */

#include "hx_locl.h"

/**
 * @page page_cms CMS/PKCS7 message functions.
 *
 * CMS is defined in RFC 3369 and is an continuation of the RSA Labs
 * standard PKCS7. The basic messages in CMS is
 *
 * - SignedData
 *   Data signed with private key (RSA, DSA, ECDSA) or secret
 *   (symmetric) key
 * - EnvelopedData
 *   Data encrypted with private key (RSA)
 * - EncryptedData
 *   Data encrypted with secret (symmetric) key.
 * - ContentInfo
 *   Wrapper structure including type and data.
 *
 *
 * See the library functions here: @ref hx509_cms
 */

#define ALLOC(X, N) (X) = calloc((N), sizeof(*(X)))
#define ALLOC_SEQ(X, N) do { (X)->len = (N); ALLOC((X)->val, (N)); } while(0)

/**
 * Wrap data and oid in a ContentInfo and encode it.
 *
 * @param oid type of the content.
 * @param buf data to be wrapped. If a NULL pointer is passed in, the
 * optional content field in the ContentInfo is not going be filled
 * in.
 * @param res the encoded buffer, the result should be freed with
 * der_free_octet_string().
 *
 * @return Returns an hx509 error code.
 *
 * @ingroup hx509_cms
 */

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_wrap_ContentInfo(const heim_oid *oid,
                           const heim_octet_string *buf,
                           heim_octet_string *res)
{
    ContentInfo ci;
    size_t size;
    int ret;

    memset(res, 0, sizeof(*res));
    memset(&ci, 0, sizeof(ci));

    ret = der_copy_oid(oid, &ci.contentType);
    if (ret)
        return ret;
    if (buf) {
        ALLOC(ci.content, 1);
        if (ci.content == NULL) {
            free_ContentInfo(&ci);
            return ENOMEM;
        }
        ci.content->data = malloc(buf->length);
        if (ci.content->data == NULL) {
            free_ContentInfo(&ci);
            return ENOMEM;
        }
        memcpy(ci.content->data, buf->data, buf->length);
        ci.content->length = buf->length;
    }

    ASN1_MALLOC_ENCODE(ContentInfo, res->data, res->length, &ci, &size, ret);
    free_ContentInfo(&ci);
    if (ret)
        return ret;
    if (res->length != size)
        _hx509_abort("internal ASN.1 encoder error");

    return 0;
}

/**
 * Decode an ContentInfo and unwrap data and oid it.
 *
 * @param in the encoded buffer.
 * @param oid type of the content.
 * @param out data to be wrapped.
 * @param have_data since the data is optional, this flag shows the
 * difference between no data and the zero length data.
 *
 * @return Returns an hx509 error code.
 *
 * @ingroup hx509_cms
 */

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_unwrap_ContentInfo(const heim_octet_string *in,
                             heim_oid *oid,
                             heim_octet_string *out,
                             int *have_data)
{
    ContentInfo ci;
    size_t size;
    int ret;

    memset(oid, 0, sizeof(*oid));
    memset(out, 0, sizeof(*out));

    ret = decode_ContentInfo(in->data, in->length, &ci, &size);
    if (ret)
        return ret;

    ret = der_copy_oid(&ci.contentType, oid);
    if (ret) {
        free_ContentInfo(&ci);
        return ret;
    }
    if (ci.content) {
        ret = der_copy_octet_string(ci.content, out);
        if (ret) {
            der_free_oid(oid);
            free_ContentInfo(&ci);
            return ret;
        }
    } else
        memset(out, 0, sizeof(*out));

    if (have_data)
        *have_data = (ci.content != NULL) ? 1 : 0;

    free_ContentInfo(&ci);

    return 0;
}

#define CMS_ID_SKI      0
#define CMS_ID_NAME     1

static int
fill_CMSIdentifier(const hx509_cert cert,
                   int type,
                   CMSIdentifier *id)
{
    int ret;

    switch (type) {
    case CMS_ID_SKI:
        id->element = choice_CMSIdentifier_subjectKeyIdentifier;
        ret = _hx509_find_extension_subject_key_id(_hx509_get_cert(cert),
                                                   &id->u.subjectKeyIdentifier);
        if (ret == 0)
            break;
        HEIM_FALLTHROUGH;
    case CMS_ID_NAME: {
        hx509_name name;

        id->element = choice_CMSIdentifier_issuerAndSerialNumber;
        ret = hx509_cert_get_issuer(cert, &name);
        if (ret)
            return ret;
        ret = hx509_name_to_Name(name, &id->u.issuerAndSerialNumber.issuer);
        hx509_name_free(&name);
        if (ret)
            return ret;

        ret = hx509_cert_get_serialnumber(cert, &id->u.issuerAndSerialNumber.serialNumber);
        break;
    }
    default:
        _hx509_abort("CMS fill identifier with unknown type");
    }
    return ret;
}

static int
unparse_CMSIdentifier(hx509_context context,
                      CMSIdentifier *id,
                      char **str)
{
    int ret = -1;

    *str = NULL;
    switch (id->element) {
    case choice_CMSIdentifier_issuerAndSerialNumber: {
        IssuerAndSerialNumber *iasn;
        char *serial, *name;

        iasn = &id->u.issuerAndSerialNumber;

        ret = _hx509_Name_to_string(&iasn->issuer, &name);
        if(ret)
            return ret;
        ret = der_print_hex_heim_integer(&iasn->serialNumber, &serial);
        if (ret) {
            free(name);
            return ret;
        }
        ret = asprintf(str, "certificate issued by %s with serial number %s",
                       name, serial);
        free(name);
        free(serial);
        break;
    }
    case choice_CMSIdentifier_subjectKeyIdentifier: {
        KeyIdentifier *ki  = &id->u.subjectKeyIdentifier;
        char *keyid;
        ssize_t len;

        len = hex_encode(ki->data, ki->length, &keyid);
        if (len < 0)
            return ENOMEM;

        if (len)
            ret = asprintf(str, "certificate with id %s", keyid);
        else
            ret = asprintf(str, "certificate");
        free(keyid);
        break;
    }
    default:
        ret = asprintf(str, "certificate has unknown CMSidentifier type");
        break;
    }
    /*
     * In the following if, we check ret and *str which should be returned/set
     * by asprintf(3) in every branch of the switch statement.
     */
    if (ret == -1 || *str == NULL)
        return ENOMEM;
    return 0;
}

static int
find_CMSIdentifier(hx509_context context,
                   CMSIdentifier *client,
                   hx509_certs certs,
                   time_t time_now,
                   hx509_cert *signer_cert,
                   int match)
{
    hx509_query q;
    hx509_cert cert;
    Certificate c;
    int ret;

    memset(&c, 0, sizeof(c));
    _hx509_query_clear(&q);

    *signer_cert = NULL;

    switch (client->element) {
    case choice_CMSIdentifier_issuerAndSerialNumber:
        q.serial = &client->u.issuerAndSerialNumber.serialNumber;
        q.issuer_name = &client->u.issuerAndSerialNumber.issuer;
        q.match = HX509_QUERY_MATCH_SERIALNUMBER|HX509_QUERY_MATCH_ISSUER_NAME;
        break;
    case choice_CMSIdentifier_subjectKeyIdentifier:
        q.subject_id = &client->u.subjectKeyIdentifier;
        q.match = HX509_QUERY_MATCH_SUBJECT_KEY_ID;
        break;
    default:
        hx509_set_error_string(context, 0, HX509_CMS_NO_RECIPIENT_CERTIFICATE,
                               "unknown CMS identifier element");
        return HX509_CMS_NO_RECIPIENT_CERTIFICATE;
    }

    q.match |= match;

    q.match |= HX509_QUERY_MATCH_TIME;
    if (time_now)
        q.timenow = time_now;
    else
        q.timenow = time(NULL);

    ret = hx509_certs_find(context, certs, &q, &cert);
    if (ret == HX509_CERT_NOT_FOUND) {
        char *str;

        ret = unparse_CMSIdentifier(context, client, &str);
        if (ret == 0) {
            hx509_set_error_string(context, 0,
                                   HX509_CMS_NO_RECIPIENT_CERTIFICATE,
                                   "Failed to find %s", str);
        } else
            hx509_clear_error_string(context);
        return HX509_CMS_NO_RECIPIENT_CERTIFICATE;
    } else if (ret) {
        hx509_set_error_string(context, HX509_ERROR_APPEND,
                               HX509_CMS_NO_RECIPIENT_CERTIFICATE,
                               "Failed to find CMS id in cert store");
        return HX509_CMS_NO_RECIPIENT_CERTIFICATE;
    }

    *signer_cert = cert;

    return 0;
}

/**
 * Decode and unencrypt EnvelopedData.
 *
 * Extract data and parameters from the EnvelopedData. Also
 * supports using detached EnvelopedData.
 *
 * @param context A hx509 context.
 * @param certs Certificate that can decrypt the EnvelopedData
 * encryption key.
 * @param flags HX509_CMS_UE flags to control the behavior.
 * @param data pointer the structure the contains the DER/BER encoded
 * EnvelopedData stucture.
 * @param length length of the data that data point to.
 * @param encryptedContent in case of detached signature, this
 * contains the actual encrypted data, otherwise it should be NULL.
 * @param time_now set the current time, if zero the library uses now as the date.
 * @param contentType output type oid, should be freed with der_free_oid().
 * @param content the data, free with der_free_octet_string().
 *
 * @return an hx509 error code.
 *
 * @ingroup hx509_cms
 */

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_unenvelope(hx509_context context,
                     hx509_certs certs,
                     int flags,
                     const void *data,
                     size_t length,
                     const heim_octet_string *encryptedContent,
                     time_t time_now,
                     heim_oid *contentType,
                     heim_octet_string *content)
{
    heim_octet_string key;
    EnvelopedData ed;
    hx509_cert cert;
    AlgorithmIdentifier *ai;
    const heim_octet_string *enccontent;
    heim_octet_string *params, params_data;
    heim_octet_string ivec;
    size_t size;
    int ret, matched = 0, findflags = 0;
    size_t i;


    memset(&key, 0, sizeof(key));
    memset(&ed, 0, sizeof(ed));
    memset(&ivec, 0, sizeof(ivec));
    memset(content, 0, sizeof(*content));
    memset(contentType, 0, sizeof(*contentType));

    if ((flags & HX509_CMS_UE_DONT_REQUIRE_KU_ENCIPHERMENT) == 0)
        findflags |= HX509_QUERY_KU_ENCIPHERMENT;

    ret = decode_EnvelopedData(data, length, &ed, &size);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to decode EnvelopedData");
        return ret;
    }

    if (ed.recipientInfos.len == 0) {
        ret = HX509_CMS_NO_RECIPIENT_CERTIFICATE;
        hx509_set_error_string(context, 0, ret,
                               "No recipient info in enveloped data");
        goto out;
    }

    enccontent = ed.encryptedContentInfo.encryptedContent;
    if (enccontent == NULL) {
        if (encryptedContent == NULL) {
            ret = HX509_CMS_NO_DATA_AVAILABLE;
            hx509_set_error_string(context, 0, ret,
                                   "Content missing from encrypted data");
            goto out;
        }
        enccontent = encryptedContent;
    } else if (encryptedContent != NULL) {
        ret = HX509_CMS_NO_DATA_AVAILABLE;
        hx509_set_error_string(context, 0, ret,
                               "Both internal and external encrypted data");
        goto out;
    }

    cert = NULL;
    for (i = 0; i < ed.recipientInfos.len; i++) {
        KeyTransRecipientInfo *ri;
        char *str;
        int ret2;

        ri = &ed.recipientInfos.val[i];

        ret = find_CMSIdentifier(context, &ri->rid, certs,
                                 time_now, &cert,
                                 HX509_QUERY_PRIVATE_KEY|findflags);
        if (ret)
            continue;

        matched = 1; /* found a matching certificate, let decrypt */

        ret = _hx509_cert_private_decrypt(context,
                                          &ri->encryptedKey,
                                          &ri->keyEncryptionAlgorithm.algorithm,
                                          cert, &key);

        hx509_cert_free(cert);
        if (ret == 0)
            break; /* successfully decrypted cert */
        cert = NULL;
        ret2 = unparse_CMSIdentifier(context, &ri->rid, &str);
        if (ret2 == 0) {
            hx509_set_error_string(context, HX509_ERROR_APPEND, ret,
                                   "Failed to decrypt with %s", str);
            free(str);
        }
    }

    if (!matched) {
        ret = HX509_CMS_NO_RECIPIENT_CERTIFICATE;
        hx509_set_error_string(context, 0, ret,
                               "No private key matched any certificate");
        goto out;
    }

    if (cert == NULL) {
        ret = HX509_CMS_NO_RECIPIENT_CERTIFICATE;
        hx509_set_error_string(context, HX509_ERROR_APPEND, ret,
                               "No private key decrypted the transfer key");
        goto out;
    }

    ret = der_copy_oid(&ed.encryptedContentInfo.contentType, contentType);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to copy EnvelopedData content oid");
        goto out;
    }

    ai = &ed.encryptedContentInfo.contentEncryptionAlgorithm;
    if (ai->parameters) {
        params_data.data = ai->parameters->data;
        params_data.length = ai->parameters->length;
        params = &params_data;
    } else
        params = NULL;

    {
        hx509_crypto crypto;

        ret = hx509_crypto_init(context, NULL, &ai->algorithm, &crypto);
        if (ret)
            goto out;

        if (flags & HX509_CMS_UE_ALLOW_WEAK)
            hx509_crypto_allow_weak(crypto);

        if (params) {
            ret = hx509_crypto_set_params(context, crypto, params, &ivec);
            if (ret) {
                hx509_crypto_destroy(crypto);
                goto out;
            }
        }

        ret = hx509_crypto_set_key_data(crypto, key.data, key.length);
        if (ret) {
            hx509_crypto_destroy(crypto);
            hx509_set_error_string(context, 0, ret,
                                   "Failed to set key for decryption "
                                   "of EnvelopedData");
            goto out;
        }

        ret = hx509_crypto_decrypt(crypto,
                                   enccontent->data,
                                   enccontent->length,
                                   ivec.length ? &ivec : NULL,
                                   content);
        hx509_crypto_destroy(crypto);
        if (ret) {
            hx509_set_error_string(context, 0, ret,
                                   "Failed to decrypt EnvelopedData");
            goto out;
        }
    }

out:

    free_EnvelopedData(&ed);
    der_free_octet_string(&key);
    if (ivec.length)
        der_free_octet_string(&ivec);
    if (ret) {
        der_free_oid(contentType);
        der_free_octet_string(content);
    }

    return ret;
}

/**
 * Encrypt and encode EnvelopedData.
 *
 * Encrypt and encode EnvelopedData. The data is encrypted with a
 * random key and the the random key is encrypted with the
 * certificate's private key. This limits what private key type can be
 * used to RSA.
 *
 * @param context A hx509 context.
 * @param flags flags to control the behavior.
 *    - HX509_CMS_EV_NO_KU_CHECK - Don't check KU on certificate
 *    - HX509_CMS_EV_ALLOW_WEAK - Allow weak crypto
 *    - HX509_CMS_EV_ID_NAME - prefer issuer name and serial number
 * @param cert Certificate to encrypt the EnvelopedData encryption key
 * with.
 * @param data pointer the data to encrypt.
 * @param length length of the data that data point to.
 * @param encryption_type Encryption cipher to use for the bulk data,
 * use NULL to get default.
 * @param contentType type of the data that is encrypted
 * @param content the output of the function,
 * free with der_free_octet_string().
 *
 * @return an hx509 error code.
 *
 * @ingroup hx509_cms
 */

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_envelope_1(hx509_context context,
                     int flags,
                     hx509_cert cert,
                     const void *data,
                     size_t length,
                     const heim_oid *encryption_type,
                     const heim_oid *contentType,
                     heim_octet_string *content)
{
    KeyTransRecipientInfo *ri;
    heim_octet_string ivec;
    heim_octet_string key;
    hx509_crypto crypto = NULL;
    int ret, cmsidflag;
    EnvelopedData ed;
    size_t size;

    memset(&ivec, 0, sizeof(ivec));
    memset(&key, 0, sizeof(key));
    memset(&ed, 0, sizeof(ed));
    memset(content, 0, sizeof(*content));

    if (encryption_type == NULL)
        encryption_type = &asn1_oid_id_aes_256_cbc;

    if ((flags & HX509_CMS_EV_NO_KU_CHECK) == 0) {
        ret = _hx509_check_key_usage(context, cert, 1 << 2, TRUE);
        if (ret)
            goto out;
    }

    ret = hx509_crypto_init(context, NULL, encryption_type, &crypto);
    if (ret)
        goto out;

    if (flags & HX509_CMS_EV_ALLOW_WEAK)
        hx509_crypto_allow_weak(crypto);

    ret = hx509_crypto_set_random_key(crypto, &key);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Create random key for EnvelopedData content");
        goto out;
    }

    ret = hx509_crypto_random_iv(crypto, &ivec);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to create a random iv");
        goto out;
    }

    ret = hx509_crypto_encrypt(crypto,
                               data,
                               length,
                               &ivec,
                               &ed.encryptedContentInfo.encryptedContent);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to encrypt EnvelopedData content");
        goto out;
    }

    {
        AlgorithmIdentifier *enc_alg;
        enc_alg = &ed.encryptedContentInfo.contentEncryptionAlgorithm;
        ret = der_copy_oid(encryption_type, &enc_alg->algorithm);
        if (ret) {
            hx509_set_error_string(context, 0, ret,
                                   "Failed to set crypto oid "
                                   "for EnvelopedData");
            goto out;
        }
        ALLOC(enc_alg->parameters, 1);
        if (enc_alg->parameters == NULL) {
            ret = ENOMEM;
            hx509_set_error_string(context, 0, ret,
                                   "Failed to allocate crypto parameters "
                                   "for EnvelopedData");
            goto out;
        }

        ret = hx509_crypto_get_params(context,
                                      crypto,
                                      &ivec,
                                      enc_alg->parameters);
        if (ret) {
            goto out;
        }
    }

    ALLOC_SEQ(&ed.recipientInfos, 1);
    if (ed.recipientInfos.val == NULL) {
        ret = ENOMEM;
        hx509_set_error_string(context, 0, ret,
                               "Failed to allocate recipients info "
                               "for EnvelopedData");
        goto out;
    }

    ri = &ed.recipientInfos.val[0];

    if (flags & HX509_CMS_EV_ID_NAME) {
        ri->version = 0;
        cmsidflag = CMS_ID_NAME;
    } else {
        ri->version = 2;
        cmsidflag = CMS_ID_SKI;
    }

    ret = fill_CMSIdentifier(cert, cmsidflag, &ri->rid);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to set CMS identifier info "
                               "for EnvelopedData");
        goto out;
    }

    ret = hx509_cert_public_encrypt(context,
                                     &key, cert,
                                     &ri->keyEncryptionAlgorithm.algorithm,
                                     &ri->encryptedKey);
    if (ret) {
        hx509_set_error_string(context, HX509_ERROR_APPEND, ret,
                               "Failed to encrypt transport key for "
                               "EnvelopedData");
        goto out;
    }

    /*
     *
     */

    ed.version = 0;
    ed.originatorInfo = NULL;

    ret = der_copy_oid(contentType, &ed.encryptedContentInfo.contentType);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to copy content oid for "
                               "EnvelopedData");
        goto out;
    }

    ed.unprotectedAttrs = NULL;

    ASN1_MALLOC_ENCODE(EnvelopedData, content->data, content->length,
                       &ed, &size, ret);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to encode EnvelopedData");
        goto out;
    }
    if (size != content->length)
        _hx509_abort("internal ASN.1 encoder error");

out:
    if (crypto)
        hx509_crypto_destroy(crypto);
    if (ret)
        der_free_octet_string(content);
    der_free_octet_string(&key);
    der_free_octet_string(&ivec);
    free_EnvelopedData(&ed);

    return ret;
}

static int
any_to_certs(hx509_context context, const SignedData *sd, hx509_certs certs)
{
    int ret;
    size_t i;

    if (sd->certificates == NULL)
        return 0;

    for (i = 0; i < sd->certificates->len; i++) {
        heim_error_t error;
        hx509_cert c;

        c = hx509_cert_init_data(context,
                                 sd->certificates->val[i].data,
                                 sd->certificates->val[i].length,
                                 &error);
        if (c == NULL) {
            ret = heim_error_get_code(error);
            heim_release(error);
            return ret;
        }
        ret = hx509_certs_add(context, certs, c);
        hx509_cert_free(c);
        if (ret)
            return ret;
    }

    return 0;
}

static const Attribute *
find_attribute(const CMSAttributes *attr, const heim_oid *oid)
{
    size_t i;
    for (i = 0; i < attr->len; i++)
        if (der_heim_oid_cmp(&attr->val[i].type, oid) == 0)
            return &attr->val[i];
    return NULL;
}

/**
 * Decode SignedData and verify that the signature is correct.
 *
 * @param context A hx509 context.
 * @param ctx a hx509 verify context.
 * @param flags to control the behavior of the function.
 *    - HX509_CMS_VS_NO_KU_CHECK - Don't check KeyUsage
 *    - HX509_CMS_VS_ALLOW_DATA_OID_MISMATCH - allow oid mismatch
 *    - HX509_CMS_VS_ALLOW_ZERO_SIGNER - no signer, see below.
 * @param data pointer to CMS SignedData encoded data.
 * @param length length of the data that data points to.
 * @param signedContent external data used for signature.
 * @param pool certificate pool to build certificates paths.
 * @param contentType free with der_free_oid().
 * @param content the output of the function, free with
 * der_free_octet_string().
 * @param signer_certs list of the cerficates used to sign this
 * request, free with hx509_certs_free().
 *
 * @return an hx509 error code.
 *
 * @ingroup hx509_cms
 */

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_verify_signed(hx509_context context,
                        hx509_verify_ctx ctx,
                        unsigned int flags,
                        const void *data,
                        size_t length,
                        const heim_octet_string *signedContent,
                        hx509_certs pool,
                        heim_oid *contentType,
                        heim_octet_string *content,
                        hx509_certs *signer_certs)
{
    unsigned int verify_flags;

    return hx509_cms_verify_signed_ext(context,
                                       ctx,
                                       flags,
                                       data,
                                       length,
                                       signedContent,
                                       pool,
                                       contentType,
                                       content,
                                       signer_certs,
                                       &verify_flags);
}

/**
 * Decode SignedData and verify that the signature is correct.
 *
 * @param context A hx509 context.
 * @param ctx a hx509 verify context.
 * @param flags to control the behaivor of the function.
 *    - HX509_CMS_VS_NO_KU_CHECK - Don't check KeyUsage
 *    - HX509_CMS_VS_ALLOW_DATA_OID_MISMATCH - allow oid mismatch
 *    - HX509_CMS_VS_ALLOW_ZERO_SIGNER - no signer, see below.
 * @param data pointer to CMS SignedData encoded data.
 * @param length length of the data that data points to.
 * @param signedContent external data used for signature.
 * @param pool certificate pool to build certificates paths.
 * @param contentType free with der_free_oid().
 * @param content the output of the function, free with
 * der_free_octet_string().
 * @param signer_certs list of the cerficates used to sign this
 * request, free with hx509_certs_free().
 * @param verify_flags flags indicating whether the certificate
 * was verified or not
 *
 * @return an hx509 error code.
 *
 * @ingroup hx509_cms
 */

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_verify_signed_ext(hx509_context context,
                            hx509_verify_ctx ctx,
                            unsigned int flags,
                            const void *data,
                            size_t length,
                            const heim_octet_string *signedContent,
                            hx509_certs pool,
                            heim_oid *contentType,
                            heim_octet_string *content,
                            hx509_certs *signer_certs,
                            unsigned int *verify_flags)
{
    SignerInfo *signer_info;
    hx509_cert cert = NULL;
    hx509_certs certs = NULL;
    SignedData sd;
    size_t size;
    int ret, found_valid_sig;
    size_t i;

    *signer_certs = NULL;
    *verify_flags = 0;

    content->data = NULL;
    content->length = 0;
    contentType->length = 0;
    contentType->components = NULL;

    memset(&sd, 0, sizeof(sd));

    ret = decode_SignedData(data, length, &sd, &size);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to decode SignedData");
        goto out;
    }

    if (sd.encapContentInfo.eContent == NULL && signedContent == NULL) {
        ret = HX509_CMS_NO_DATA_AVAILABLE;
        hx509_set_error_string(context, 0, ret,
                               "No content data in SignedData");
        goto out;
    }
    if (sd.encapContentInfo.eContent && signedContent) {
        ret = HX509_CMS_NO_DATA_AVAILABLE;
        hx509_set_error_string(context, 0, ret,
                               "Both external and internal SignedData");
        goto out;
    }

    if (sd.encapContentInfo.eContent)
        ret = der_copy_octet_string(sd.encapContentInfo.eContent, content);
    else
        ret = der_copy_octet_string(signedContent, content);
    if (ret) {
        hx509_set_error_string(context, 0, ret, "malloc: out of memory");
        goto out;
    }

    ret = hx509_certs_init(context, "MEMORY:cms-cert-buffer",
                           0, NULL, &certs);
    if (ret)
        goto out;

    ret = hx509_certs_init(context, "MEMORY:cms-signer-certs",
                           0, NULL, signer_certs);
    if (ret)
        goto out;

    /* XXX Check CMS version */

    ret = any_to_certs(context, &sd, certs);
    if (ret)
        goto out;

    if (pool) {
        ret = hx509_certs_merge(context, certs, pool);
        if (ret)
            goto out;
    }

    for (found_valid_sig = 0, i = 0; i < sd.signerInfos.len; i++) {
        heim_octet_string signed_data = { 0, NULL };
        const heim_oid *match_oid;
        heim_oid decode_oid;

        signer_info = &sd.signerInfos.val[i];
        match_oid = NULL;

        if (signer_info->signature.length == 0) {
            ret = HX509_CMS_MISSING_SIGNER_DATA;
            hx509_set_error_string(context, 0, ret,
                                   "SignerInfo %zu in SignedData "
                                   "missing signature", i);
            continue;
        }

        ret = find_CMSIdentifier(context, &signer_info->sid, certs,
                                 _hx509_verify_get_time(ctx), &cert,
                                 HX509_QUERY_KU_DIGITALSIGNATURE);
        if (ret) {
            /**
             * If HX509_CMS_VS_NO_KU_CHECK is set, allow more liberal
             * search for matching certificates by not considering
             * KeyUsage bits on the certificates.
             */
            if ((flags & HX509_CMS_VS_NO_KU_CHECK) == 0)
                continue;

            ret = find_CMSIdentifier(context, &signer_info->sid, certs,
                                     _hx509_verify_get_time(ctx), &cert,
                                     0);
            if (ret)
                continue;

        }

        if (signer_info->signedAttrs) {
            const Attribute *attr;

            CMSAttributes sa;
            heim_octet_string os;

            sa.val = signer_info->signedAttrs->val;
            sa.len = signer_info->signedAttrs->len;

            /* verify that signature exists */
            attr = find_attribute(&sa, &asn1_oid_id_pkcs9_messageDigest);
            if (attr == NULL) {
                ret = HX509_CRYPTO_SIGNATURE_MISSING;
                hx509_set_error_string(context, 0, ret,
                                       "SignerInfo has signed attributes "
                                       "but messageDigest (signature) "
                                       "is missing");
                goto next_signature;
            }
            if (attr->value.len != 1) {
                ret = HX509_CRYPTO_SIGNATURE_MISSING;
                hx509_set_error_string(context, 0, ret,
                                       "SignerInfo has more than one "
                                       "messageDigest (signature)");
                goto next_signature;
            }

            ret = decode_MessageDigest(attr->value.val[0].data,
                                       attr->value.val[0].length,
                                       &os,
                                       &size);
            if (ret) {
                hx509_set_error_string(context, 0, ret,
                                       "Failed to decode "
                                       "messageDigest (signature)");
                goto next_signature;
            }

            ret = _hx509_verify_signature(context,
                                          NULL,
                                          &signer_info->digestAlgorithm,
                                          content,
                                          &os);
            der_free_octet_string(&os);
            if (ret) {
                hx509_set_error_string(context, HX509_ERROR_APPEND, ret,
                                       "Failed to verify messageDigest");
                goto next_signature;
            }

            /*
             * Fetch content oid inside signedAttrs or set it to
             * id-pkcs7-data.
             */
            attr = find_attribute(&sa, &asn1_oid_id_pkcs9_contentType);
            if (attr == NULL) {
                match_oid = &asn1_oid_id_pkcs7_data;
            } else {
                if (attr->value.len != 1) {
                    ret = HX509_CMS_DATA_OID_MISMATCH;
                    hx509_set_error_string(context, 0, ret,
                                           "More than one oid in signedAttrs");
                    goto next_signature;

                }
                ret = decode_ContentType(attr->value.val[0].data,
                                         attr->value.val[0].length,
                                         &decode_oid,
                                         &size);
                if (ret) {
                    hx509_set_error_string(context, 0, ret,
                                           "Failed to decode "
                                           "oid in signedAttrs");
                    goto next_signature;
                }
                match_oid = &decode_oid;
            }

            ASN1_MALLOC_ENCODE(CMSAttributes,
                               signed_data.data,
                               signed_data.length,
                               &sa,
                               &size, ret);
            if (ret) {
                if (match_oid == &decode_oid)
                    der_free_oid(&decode_oid);
                hx509_clear_error_string(context);
                goto next_signature;
            }
            if (size != signed_data.length)
                _hx509_abort("internal ASN.1 encoder error");

        } else {
            signed_data.data = content->data;
            signed_data.length = content->length;
            match_oid = &asn1_oid_id_pkcs7_data;
        }

        /**
         * If HX509_CMS_VS_ALLOW_DATA_OID_MISMATCH, allow
         * encapContentInfo mismatch with the oid in signedAttributes
         * (or if no signedAttributes where use, pkcs7-data oid).
         * This is only needed to work with broken CMS implementations
         * that doesn't follow CMS signedAttributes rules.
         */

        if (der_heim_oid_cmp(match_oid, &sd.encapContentInfo.eContentType) &&
            (flags & HX509_CMS_VS_ALLOW_DATA_OID_MISMATCH) == 0) {
            ret = HX509_CMS_DATA_OID_MISMATCH;
            hx509_set_error_string(context, 0, ret,
                                   "Oid in message mismatch from the expected");
        }
        if (match_oid == &decode_oid)
            der_free_oid(&decode_oid);

        if (ret == 0) {
            ret = hx509_verify_signature(context,
                                         cert,
                                         &signer_info->signatureAlgorithm,
                                         &signed_data,
                                         &signer_info->signature);
            if (ret)
                hx509_set_error_string(context, HX509_ERROR_APPEND, ret,
                                       "Failed to verify signature in "
                                       "CMS SignedData");
        }
        if (signed_data.data != NULL && content->data != signed_data.data) {
            free(signed_data.data);
            signed_data.data = NULL;
        }
        if (ret)
            goto next_signature;

        /**
         * If HX509_CMS_VS_NO_VALIDATE flags is set, return the signer
         * certificate unconditionally but do not set HX509_CMS_VSE_VALIDATED.
         */
        ret = hx509_verify_path(context, ctx, cert, certs);
        if (ret == 0 || (flags & HX509_CMS_VS_NO_VALIDATE)) {
            if (ret == 0)
                *verify_flags |= HX509_CMS_VSE_VALIDATED;

            ret = hx509_certs_add(context, *signer_certs, cert);
            if (ret == 0)
                found_valid_sig++;
        }

    next_signature:
        if (cert)
            hx509_cert_free(cert);
        cert = NULL;
    }
    /**
     * If HX509_CMS_VS_ALLOW_ZERO_SIGNER is set, allow empty
     * SignerInfo (no signatures). If SignedData has no signatures,
     * the function will return 0 with signer_certs set to NULL. Zero
     * signers is allowed by the standard, but since it's only useful
     * in corner cases, it's made into a flag that the caller has to
     * turn on.
     */
    if (sd.signerInfos.len == 0 && (flags & HX509_CMS_VS_ALLOW_ZERO_SIGNER)) {
        if (*signer_certs)
            hx509_certs_free(signer_certs);
    } else if (found_valid_sig == 0) {
        if (ret == 0) {
            ret = HX509_CMS_SIGNER_NOT_FOUND;
            hx509_set_error_string(context, 0, ret,
                                   "No signers were found");
        }
        goto out;
    }

    ret = der_copy_oid(&sd.encapContentInfo.eContentType, contentType);
    if (ret) {
        hx509_clear_error_string(context);
        goto out;
    }

out:
    free_SignedData(&sd);
    if (certs)
        hx509_certs_free(&certs);
    if (ret) {
        if (content->data)
            der_free_octet_string(content);
        if (*signer_certs)
            hx509_certs_free(signer_certs);
        der_free_oid(contentType);
        der_free_octet_string(content);
    }

    return ret;
}

static int
add_one_attribute(Attribute **attr,
                  unsigned int *len,
                  const heim_oid *oid,
                  heim_octet_string *data)
{
    void *d;
    int ret;

    d = realloc(*attr, sizeof((*attr)[0]) * (*len + 1));
    if (d == NULL)
        return ENOMEM;
    (*attr) = d;

    ret = der_copy_oid(oid, &(*attr)[*len].type);
    if (ret)
        return ret;

    ALLOC_SEQ(&(*attr)[*len].value, 1);
    if ((*attr)[*len].value.val == NULL) {
        der_free_oid(&(*attr)[*len].type);
        return ENOMEM;
    }

    (*attr)[*len].value.val[0].data = data->data;
    (*attr)[*len].value.val[0].length = data->length;

    *len += 1;

    return 0;
}

/**
 * Decode SignedData and verify that the signature is correct.
 *
 * @param context A hx509 context.
 * @param flags
 * @param eContentType the type of the data.
 * @param data data to sign
 * @param length length of the data that data points to.
 * @param digest_alg digest algorithm to use, use NULL to get the
 * default or the peer determined algorithm.
 * @param cert certificate to use for signing the data.
 * @param peer info about the peer the message to send the message to,
 * like what digest algorithm to use.
 * @param anchors trust anchors that the client will use, used to
 * polulate the certificates included in the message
 * @param pool certificates to use in try to build the path to the
 * trust anchors.
 * @param signed_data the output of the function, free with
 * der_free_octet_string().
 *
 * @return Returns an hx509 error code.
 *
 * @ingroup hx509_cms
 */

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_create_signed_1(hx509_context context,
                          int flags,
                          const heim_oid *eContentType,
                          const void *data, size_t length,
                          const AlgorithmIdentifier *digest_alg,
                          hx509_cert cert,
                          hx509_peer_info peer,
                          hx509_certs anchors,
                          hx509_certs pool,
                          heim_octet_string *signed_data)
{
    hx509_certs certs;
    int ret = 0;

    signed_data->data = NULL;
    signed_data->length = 0;

    ret = hx509_certs_init(context, "MEMORY:certs", 0, NULL, &certs);
    if (ret)
        return ret;
    ret = hx509_certs_add(context, certs, cert);
    if (ret)
        goto out;

    ret = hx509_cms_create_signed(context, flags, eContentType, data, length,
                                  digest_alg, certs, peer, anchors, pool,
                                  signed_data);

 out:
    hx509_certs_free(&certs);
    return ret;
}

struct sigctx {
    SignedData sd;
    const AlgorithmIdentifier *digest_alg;
    const heim_oid *eContentType;
    heim_octet_string content;
    hx509_peer_info peer;
    int cmsidflag;
    int leafonly;
    hx509_certs certs;
    hx509_certs anchors;
    hx509_certs pool;
};

static int HX509_LIB_CALL
sig_process(hx509_context context, void *ctx, hx509_cert cert)
{
    struct sigctx *sigctx = ctx;
    heim_octet_string buf, sigdata = { 0, NULL };
    SignerInfo *signer_info = NULL;
    AlgorithmIdentifier digest;
    size_t size;
    void *ptr;
    int ret;
    SignedData *sd = &sigctx->sd;
    hx509_path path;

    memset(&digest, 0, sizeof(digest));
    memset(&path, 0, sizeof(path));

    if (_hx509_cert_private_key(cert) == NULL) {
        hx509_set_error_string(context, 0, HX509_PRIVATE_KEY_MISSING,
                               "Private key missing for signing");
        return HX509_PRIVATE_KEY_MISSING;
    }

    if (sigctx->digest_alg) {
        ret = copy_AlgorithmIdentifier(sigctx->digest_alg, &digest);
        if (ret)
            hx509_clear_error_string(context);
    } else {
        ret = hx509_crypto_select(context, HX509_SELECT_DIGEST,
                                  _hx509_cert_private_key(cert),
                                  sigctx->peer, &digest);
    }
    if (ret)
        goto out;

    /*
     * Allocate on more signerInfo and do the signature processing
     */

    ptr = realloc(sd->signerInfos.val,
                  (sd->signerInfos.len + 1) * sizeof(sd->signerInfos.val[0]));
    if (ptr == NULL) {
        ret = ENOMEM;
        goto out;
    }
    sd->signerInfos.val = ptr;

    signer_info = &sd->signerInfos.val[sd->signerInfos.len];

    memset(signer_info, 0, sizeof(*signer_info));

    signer_info->version = 1;

    ret = fill_CMSIdentifier(cert, sigctx->cmsidflag, &signer_info->sid);
    if (ret) {
        hx509_clear_error_string(context);
        goto out;
    }

    signer_info->signedAttrs = NULL;
    signer_info->unsignedAttrs = NULL;

    ret = copy_AlgorithmIdentifier(&digest, &signer_info->digestAlgorithm);
    if (ret) {
        hx509_clear_error_string(context);
        goto out;
    }

    /*
     * If it isn't pkcs7-data send signedAttributes
     */

    if (der_heim_oid_cmp(sigctx->eContentType, &asn1_oid_id_pkcs7_data) != 0) {
        CMSAttributes sa;
        heim_octet_string sig;

        ALLOC(signer_info->signedAttrs, 1);
        if (signer_info->signedAttrs == NULL) {
            ret = ENOMEM;
            goto out;
        }

        ret = _hx509_create_signature(context,
                                      NULL,
                                      &digest,
                                      &sigctx->content,
                                      NULL,
                                      &sig);
        if (ret)
            goto out;

        ASN1_MALLOC_ENCODE(MessageDigest,
                           buf.data,
                           buf.length,
                           &sig,
                           &size,
                           ret);
        der_free_octet_string(&sig);
        if (ret) {
            hx509_clear_error_string(context);
            goto out;
        }
        if (size != buf.length)
            _hx509_abort("internal ASN.1 encoder error");

        ret = add_one_attribute(&signer_info->signedAttrs->val,
                                &signer_info->signedAttrs->len,
                                &asn1_oid_id_pkcs9_messageDigest,
                                &buf);
        if (ret) {
            free(buf.data);
            hx509_clear_error_string(context);
            goto out;
        }


        ASN1_MALLOC_ENCODE(ContentType,
                           buf.data,
                           buf.length,
                           sigctx->eContentType,
                           &size,
                           ret);
        if (ret)
            goto out;
        if (size != buf.length)
            _hx509_abort("internal ASN.1 encoder error");

        ret = add_one_attribute(&signer_info->signedAttrs->val,
                                &signer_info->signedAttrs->len,
                                &asn1_oid_id_pkcs9_contentType,
                                &buf);
        if (ret) {
            free(buf.data);
            hx509_clear_error_string(context);
            goto out;
        }

        sa.val = signer_info->signedAttrs->val;
        sa.len = signer_info->signedAttrs->len;

        ASN1_MALLOC_ENCODE(CMSAttributes,
                           sigdata.data,
                           sigdata.length,
                           &sa,
                           &size,
                           ret);
        if (ret) {
            hx509_clear_error_string(context);
            goto out;
        }
        if (size != sigdata.length)
            _hx509_abort("internal ASN.1 encoder error");
    } else {
        sigdata.data = sigctx->content.data;
        sigdata.length = sigctx->content.length;
    }

    {
        AlgorithmIdentifier sigalg;

        ret = hx509_crypto_select(context, HX509_SELECT_PUBLIC_SIG,
                                  _hx509_cert_private_key(cert), sigctx->peer,
                                  &sigalg);
        if (ret)
            goto out;

        ret = _hx509_create_signature(context,
                                      _hx509_cert_private_key(cert),
                                      &sigalg,
                                      &sigdata,
                                      &signer_info->signatureAlgorithm,
                                      &signer_info->signature);
        free_AlgorithmIdentifier(&sigalg);
        if (ret)
            goto out;
    }

    sigctx->sd.signerInfos.len++;
    signer_info = NULL;

    /*
     * Provide best effort path
     */
    if (sigctx->certs) {
        unsigned int i;

        if (sigctx->pool && sigctx->leafonly == 0) {
            _hx509_calculate_path(context,
                                  HX509_CALCULATE_PATH_NO_ANCHOR,
                                  time(NULL),
                                  sigctx->anchors,
                                  0,
                                  cert,
                                  sigctx->pool,
                                  &path);
        } else
            _hx509_path_append(context, &path, cert);

        for (i = 0; i < path.len; i++) {
            /* XXX remove dups */
            ret = hx509_certs_add(context, sigctx->certs, path.val[i]);
            if (ret) {
                hx509_clear_error_string(context);
                goto out;
            }
        }
    }

 out:
    if (signer_info)
        free_SignerInfo(signer_info);
    if (sigdata.data != sigctx->content.data)
        der_free_octet_string(&sigdata);
    _hx509_path_free(&path);
    free_AlgorithmIdentifier(&digest);

    return ret;
}

static int HX509_LIB_CALL
cert_process(hx509_context context, void *ctx, hx509_cert cert)
{
    struct sigctx *sigctx = ctx;
    const unsigned int i = sigctx->sd.certificates->len;
    void *ptr;
    int ret;

    ptr = realloc(sigctx->sd.certificates->val,
                  (i + 1) * sizeof(sigctx->sd.certificates->val[0]));
    if (ptr == NULL)
        return ENOMEM;
    sigctx->sd.certificates->val = ptr;

    ret = hx509_cert_binary(context, cert,
                            &sigctx->sd.certificates->val[i]);
    if (ret == 0)
        sigctx->sd.certificates->len++;

    return ret;
}

static int
cmp_AlgorithmIdentifier(const AlgorithmIdentifier *p, const AlgorithmIdentifier *q)
{
    return der_heim_oid_cmp(&p->algorithm, &q->algorithm);
}

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_create_signed(hx509_context context,
                        int flags,
                        const heim_oid *eContentType,
                        const void *data, size_t length,
                        const AlgorithmIdentifier *digest_alg,
                        hx509_certs certs,
                        hx509_peer_info peer,
                        hx509_certs anchors,
                        hx509_certs pool,
                        heim_octet_string *signed_data)
{
    unsigned int i, j;
    int ret;
    size_t size;
    struct sigctx sigctx;

    memset(&sigctx, 0, sizeof(sigctx));

    if (eContentType == NULL)
        eContentType = &asn1_oid_id_pkcs7_data;

    sigctx.digest_alg = digest_alg;
    sigctx.content.data = rk_UNCONST(data);
    sigctx.content.length = length;
    sigctx.eContentType = eContentType;
    sigctx.peer = peer;
    /**
     * Use HX509_CMS_SIGNATURE_ID_NAME to preferred use of issuer name
     * and serial number if possible. Otherwise subject key identifier
     * will preferred.
     */
    if (flags & HX509_CMS_SIGNATURE_ID_NAME)
        sigctx.cmsidflag = CMS_ID_NAME;
    else
        sigctx.cmsidflag = CMS_ID_SKI;

    /**
     * Use HX509_CMS_SIGNATURE_LEAF_ONLY to only request leaf
     * certificates to be added to the SignedData.
     */
    sigctx.leafonly = (flags & HX509_CMS_SIGNATURE_LEAF_ONLY) ? 1 : 0;

    /**
     * Use HX509_CMS_NO_CERTS to make the SignedData contain no
     * certificates, overrides HX509_CMS_SIGNATURE_LEAF_ONLY.
     */

    if ((flags & HX509_CMS_SIGNATURE_NO_CERTS) == 0) {
        ret = hx509_certs_init(context, "MEMORY:certs", 0, NULL, &sigctx.certs);
        if (ret)
            return ret;
    }

    sigctx.anchors = anchors;
    sigctx.pool = pool;

    sigctx.sd.version = cMSVersion_v3;

    ret = der_copy_oid(eContentType, &sigctx.sd.encapContentInfo.eContentType);
    if (ret)
        goto out;

    /**
     * Use HX509_CMS_SIGNATURE_DETACHED to create detached signatures.
     */
    if ((flags & HX509_CMS_SIGNATURE_DETACHED) == 0) {
        ALLOC(sigctx.sd.encapContentInfo.eContent, 1);
        if (sigctx.sd.encapContentInfo.eContent == NULL) {
            hx509_clear_error_string(context);
            ret = ENOMEM;
            goto out;
        }

        sigctx.sd.encapContentInfo.eContent->data = malloc(length);
        if (sigctx.sd.encapContentInfo.eContent->data == NULL) {
            hx509_clear_error_string(context);
            ret = ENOMEM;
            goto out;
        }
        memcpy(sigctx.sd.encapContentInfo.eContent->data, data, length);
        sigctx.sd.encapContentInfo.eContent->length = length;
    }

    /**
     * Use HX509_CMS_SIGNATURE_NO_SIGNER to create no sigInfo (no
     * signatures).
     */
    if ((flags & HX509_CMS_SIGNATURE_NO_SIGNER) == 0) {
        ret = hx509_certs_iter_f(context, certs, sig_process, &sigctx);
        if (ret)
            goto out;
    }

    if (sigctx.sd.signerInfos.len) {

        /*
         * For each signerInfo, collect all different digest types.
         */
        for (i = 0; i < sigctx.sd.signerInfos.len; i++) {
            AlgorithmIdentifier *di =
                &sigctx.sd.signerInfos.val[i].digestAlgorithm;

            for (j = 0; j < sigctx.sd.digestAlgorithms.len; j++)
                if (cmp_AlgorithmIdentifier(di, &sigctx.sd.digestAlgorithms.val[j]) == 0)
                    break;
            if (j == sigctx.sd.digestAlgorithms.len) {
                ret = add_DigestAlgorithmIdentifiers(&sigctx.sd.digestAlgorithms, di);
                if (ret) {
                    hx509_clear_error_string(context);
                    goto out;
                }
            }
        }
    }

    /*
     * Add certs we think are needed, build as part of sig_process
     */
    if (sigctx.certs) {
        ALLOC(sigctx.sd.certificates, 1);
        if (sigctx.sd.certificates == NULL) {
            hx509_clear_error_string(context);
            ret = ENOMEM;
            goto out;
        }

        ret = hx509_certs_iter_f(context, sigctx.certs, cert_process, &sigctx);
        if (ret)
            goto out;
    }

    ASN1_MALLOC_ENCODE(SignedData,
                       signed_data->data, signed_data->length,
                       &sigctx.sd, &size, ret);
    if (ret) {
        hx509_clear_error_string(context);
        goto out;
    }
    if (signed_data->length != size)
        _hx509_abort("internal ASN.1 encoder error");

out:
    hx509_certs_free(&sigctx.certs);
    free_SignedData(&sigctx.sd);

    return ret;
}

HX509_LIB_FUNCTION int HX509_LIB_CALL
hx509_cms_decrypt_encrypted(hx509_context context,
                            hx509_lock lock,
                            const void *data,
                            size_t length,
                            heim_oid *contentType,
                            heim_octet_string *content)
{
    heim_octet_string cont;
    CMSEncryptedData ed;
    AlgorithmIdentifier *ai;
    int ret;

    memset(content, 0, sizeof(*content));
    memset(&cont, 0, sizeof(cont));

    ret = decode_CMSEncryptedData(data, length, &ed, NULL);
    if (ret) {
        hx509_set_error_string(context, 0, ret,
                               "Failed to decode CMSEncryptedData");
        return ret;
    }

    if (ed.encryptedContentInfo.encryptedContent == NULL) {
        ret = HX509_CMS_NO_DATA_AVAILABLE;
        hx509_set_error_string(context, 0, ret,
                               "No content in EncryptedData");
        goto out;
    }

    ret = der_copy_oid(&ed.encryptedContentInfo.contentType, contentType);
    if (ret) {
        hx509_clear_error_string(context);
        goto out;
    }

    ai = &ed.encryptedContentInfo.contentEncryptionAlgorithm;
    if (ai->parameters == NULL) {
        ret = HX509_ALG_NOT_SUPP;
        hx509_clear_error_string(context);
        goto out;
    }

    ret = _hx509_pbe_decrypt(context,
                             lock,
                             ai,
                             ed.encryptedContentInfo.encryptedContent,
                             &cont);
    if (ret)
        goto out;

    *content = cont;

out:
    if (ret) {
        if (cont.data)
            free(cont.data);
    }
    free_CMSEncryptedData(&ed);
    return ret;
}