/*
 * Copyright (c) 2004 - 2008 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"
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif

#ifdef HAVE_DLOPEN

#include "pkcs11.h"

struct p11_slot {
    int flags;
#define P11_SESSION             1
#define P11_SESSION_IN_USE      2
#define P11_LOGIN_REQ           4
#define P11_LOGIN_DONE          8
#define P11_TOKEN_PRESENT       16
    CK_SESSION_HANDLE session;
    CK_SLOT_ID id;
    CK_BBOOL token;
    char *name;
    hx509_certs certs;
    char *pin;
    struct {
        CK_MECHANISM_TYPE_PTR list;
        CK_ULONG num;
        CK_MECHANISM_INFO_PTR *infos;
    } mechs;
};

struct p11_module {
    void *dl_handle;
    CK_FUNCTION_LIST_PTR funcs;
    CK_ULONG num_slots;
    unsigned int ref;
    struct p11_slot *slot;
};

#define P11FUNC(module,f,args) (*(module)->funcs->C_##f)args

static int p11_get_session(hx509_context,
                           struct p11_module *,
                           struct p11_slot *,
                           hx509_lock,
                           CK_SESSION_HANDLE *);
static int p11_put_session(struct p11_module *,
                           struct p11_slot *,
                           CK_SESSION_HANDLE);
static void p11_release_module(struct p11_module *);

static int p11_list_keys(hx509_context,
                         struct p11_module *,
                         struct p11_slot *,
                         CK_SESSION_HANDLE,
                         hx509_lock,
                         hx509_certs *);

/*
 *
 */

struct p11_rsa {
    struct p11_module *p;
    struct p11_slot *slot;
    CK_OBJECT_HANDLE private_key;
    CK_OBJECT_HANDLE public_key;
};

static int
p11_rsa_public_encrypt(int flen,
                       const unsigned char *from,
                       unsigned char *to,
                       RSA *rsa,
                       int padding)
{
    return -1;
}

static int
p11_rsa_public_decrypt(int flen,
                       const unsigned char *from,
                       unsigned char *to,
                       RSA *rsa,
                       int padding)
{
    return -1;
}


static int
p11_rsa_private_encrypt(int flen,
                        const unsigned char *from,
                        unsigned char *to,
                        RSA *rsa,
                        int padding)
{
    struct p11_rsa *p11rsa = RSA_get_app_data(rsa);
    CK_OBJECT_HANDLE key = p11rsa->private_key;
    CK_SESSION_HANDLE session;
    CK_MECHANISM mechanism;
    CK_ULONG ck_sigsize;
    int ret;

    if (padding != RSA_PKCS1_PADDING)
        return -1;

    memset(&mechanism, 0, sizeof(mechanism));
    mechanism.mechanism = CKM_RSA_PKCS;

    ck_sigsize = RSA_size(rsa);

    ret = p11_get_session(NULL, p11rsa->p, p11rsa->slot, NULL, &session);
    if (ret)
        return -1;

    ret = P11FUNC(p11rsa->p, SignInit, (session, &mechanism, key));
    if (ret != CKR_OK) {
        p11_put_session(p11rsa->p, p11rsa->slot, session);
        return -1;
    }

    ret = P11FUNC(p11rsa->p, Sign,
                  (session, (CK_BYTE *)(intptr_t)from, flen, to, &ck_sigsize));
    p11_put_session(p11rsa->p, p11rsa->slot, session);
    if (ret != CKR_OK)
        return -1;

    return ck_sigsize;
}

static int
p11_rsa_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
                        RSA * rsa, int padding)
{
    struct p11_rsa *p11rsa = RSA_get_app_data(rsa);
    CK_OBJECT_HANDLE key = p11rsa->private_key;
    CK_SESSION_HANDLE session;
    CK_MECHANISM mechanism;
    CK_ULONG ck_sigsize;
    int ret;

    if (padding != RSA_PKCS1_PADDING)
        return -1;

    memset(&mechanism, 0, sizeof(mechanism));
    mechanism.mechanism = CKM_RSA_PKCS;

    ck_sigsize = RSA_size(rsa);

    ret = p11_get_session(NULL, p11rsa->p, p11rsa->slot, NULL, &session);
    if (ret)
        return -1;

    ret = P11FUNC(p11rsa->p, DecryptInit, (session, &mechanism, key));
    if (ret != CKR_OK) {
        p11_put_session(p11rsa->p, p11rsa->slot, session);
        return -1;
    }

    ret = P11FUNC(p11rsa->p, Decrypt,
                  (session, (CK_BYTE *)(intptr_t)from, flen, to, &ck_sigsize));
    p11_put_session(p11rsa->p, p11rsa->slot, session);
    if (ret != CKR_OK)
        return -1;

    return ck_sigsize;
}

static int
p11_rsa_init(RSA *rsa)
{
    return 1;
}

static int
p11_rsa_finish(RSA *rsa)
{
    struct p11_rsa *p11rsa = RSA_get_app_data(rsa);
    p11_release_module(p11rsa->p);
    free(p11rsa);
    return 1;
}

static const RSA_METHOD *
get_p11_rsa_pkcs1_method(void)
{
    static const RSA_METHOD *p11_rsa_pkcs1_method;
    RSA_METHOD *new_method;

    if (p11_rsa_pkcs1_method != NULL)
        return p11_rsa_pkcs1_method;

    new_method = RSA_meth_new("hx509 PKCS11 PKCS#1 RSA", 0);
    if (new_method == NULL)
        return NULL;

    if (RSA_meth_set_pub_enc(new_method, p11_rsa_public_encrypt) != 1)
        goto out;

    if (RSA_meth_set_pub_dec(new_method, p11_rsa_public_decrypt) != 1)
        goto out;

    if (RSA_meth_set_priv_enc(new_method, p11_rsa_private_encrypt) != 1)
        goto out;

    if (RSA_meth_set_priv_dec(new_method, p11_rsa_private_decrypt) != 1)
        goto out;

    if (RSA_meth_set_init(new_method, p11_rsa_init) != 1)
        goto out;

    if (RSA_meth_set_finish(new_method, p11_rsa_finish) != 1)
        goto out;

    /*
     * This might overwrite a previously-created method if multiple
     * threads invoke this concurrently which will leak memory.
     */
    p11_rsa_pkcs1_method = new_method;
    return p11_rsa_pkcs1_method;
out:
    RSA_meth_free(new_method);
    return NULL;
}

/*
 *
 */

static int
p11_mech_info(hx509_context context,
              struct p11_module *p,
              struct p11_slot *slot,
              int num)
{
    CK_ULONG i;
    int ret;

    ret = P11FUNC(p, GetMechanismList, (slot->id, NULL_PTR, &i));
    if (ret) {
        hx509_set_error_string(context, 0, HX509_PKCS11_NO_MECH,
                               "Failed to get mech list count for slot %d",
                               num);
        return HX509_PKCS11_NO_MECH;
    }
    if (i == 0) {
        hx509_set_error_string(context, 0, HX509_PKCS11_NO_MECH,
                               "no mech supported for slot %d", num);
        return HX509_PKCS11_NO_MECH;
    }
    slot->mechs.list = calloc(i, sizeof(slot->mechs.list[0]));
    if (slot->mechs.list == NULL) {
        hx509_set_error_string(context, 0, ENOMEM,
                               "out of memory");
        return ENOMEM;
    }
    slot->mechs.num = i;
    ret = P11FUNC(p, GetMechanismList, (slot->id, slot->mechs.list, &i));
    if (ret) {
        hx509_set_error_string(context, 0, HX509_PKCS11_NO_MECH,
                               "Failed to get mech list for slot %d",
                               num);
        return HX509_PKCS11_NO_MECH;
    }
    assert(i == slot->mechs.num);

    slot->mechs.infos = calloc(i, sizeof(*slot->mechs.infos));
    if (slot->mechs.list == NULL) {
        hx509_set_error_string(context, 0, ENOMEM,
                               "out of memory");
        return ENOMEM;
    }

    for (i = 0; i < slot->mechs.num; i++) {
        slot->mechs.infos[i] = calloc(1, sizeof(*(slot->mechs.infos[0])));
        if (slot->mechs.infos[i] == NULL) {
            hx509_set_error_string(context, 0, ENOMEM,
                                   "out of memory");
            return ENOMEM;
        }
        ret = P11FUNC(p, GetMechanismInfo, (slot->id, slot->mechs.list[i],
                                            slot->mechs.infos[i]));
        if (ret) {
            hx509_set_error_string(context, 0, HX509_PKCS11_NO_MECH,
                                   "Failed to get mech info for slot %d",
                                   num);
            return HX509_PKCS11_NO_MECH;
        }
    }

    return 0;
}

static int
p11_init_slot(hx509_context context,
              struct p11_module *p,
              hx509_lock lock,
              CK_SLOT_ID id,
              int num,
              struct p11_slot *slot)
{
    CK_SESSION_HANDLE session;
    CK_SLOT_INFO slot_info;
    CK_TOKEN_INFO token_info;
    size_t i;
    int ret;

    slot->certs = NULL;
    slot->id = id;

    ret = P11FUNC(p, GetSlotInfo, (slot->id, &slot_info));
    if (ret) {
        hx509_set_error_string(context, 0, HX509_PKCS11_TOKEN_CONFUSED,
                               "Failed to init PKCS11 slot %d",
                               num);
        return HX509_PKCS11_TOKEN_CONFUSED;
    }

    for (i = sizeof(slot_info.slotDescription) - 1; i > 0; i--) {
        char c = slot_info.slotDescription[i];
        if (c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\0')
            continue;
        i++;
        break;
    }

    asprintf(&slot->name, "%.*s",
             (int)i, slot_info.slotDescription);

    if ((slot_info.flags & CKF_TOKEN_PRESENT) == 0)
        return 0;

    ret = P11FUNC(p, GetTokenInfo, (slot->id, &token_info));
    if (ret) {
        hx509_set_error_string(context, 0, HX509_PKCS11_NO_TOKEN,
                               "Failed to init PKCS11 slot %d "
                               "with error 0x08x",
                               num, ret);
        return HX509_PKCS11_NO_TOKEN;
    }
    slot->flags |= P11_TOKEN_PRESENT;

    if (token_info.flags & CKF_LOGIN_REQUIRED)
        slot->flags |= P11_LOGIN_REQ;

    ret = p11_get_session(context, p, slot, lock, &session);
    if (ret)
        return ret;

    ret = p11_mech_info(context, p, slot, num);
    if (ret)
        goto out;

    ret = p11_list_keys(context, p, slot, session, lock, &slot->certs);
 out:
    p11_put_session(p, slot, session);

    return ret;
}

static int
p11_get_session(hx509_context context,
                struct p11_module *p,
                struct p11_slot *slot,
                hx509_lock lock,
                CK_SESSION_HANDLE *psession)
{
    CK_RV ret;

    if (slot->flags & P11_SESSION_IN_USE)
        _hx509_abort("slot already in session");

    if (slot->flags & P11_SESSION) {
        slot->flags |= P11_SESSION_IN_USE;
        *psession = slot->session;
        return 0;
    }

    ret = P11FUNC(p, OpenSession, (slot->id,
                                   CKF_SERIAL_SESSION,
                                   NULL,
                                   NULL,
                                   &slot->session));
    if (ret != CKR_OK) {
        if (context)
            hx509_set_error_string(context, 0, HX509_PKCS11_OPEN_SESSION,
                                   "Failed to OpenSession for slot id %d "
                                   "with error: 0x%08x",
                                   (int)slot->id, ret);
        return HX509_PKCS11_OPEN_SESSION;
    }

    slot->flags |= P11_SESSION;

    /*
     * If we have have to login, and haven't tried before and have a
     * prompter or known to work pin code.
     *
     * This code is very conversative and only uses the prompter in
     * the hx509_lock, the reason is that it's bad to try many
     * passwords on a pkcs11 token, it might lock up and have to be
     * unlocked by a administrator.
     *
     * XXX try harder to not use pin several times on the same card.
     */

    if (   (slot->flags & P11_LOGIN_REQ)
        && (slot->flags & P11_LOGIN_DONE) == 0
        && (lock || slot->pin))
    {
        hx509_prompt prompt;
        char pin[20];
        char *str;

        if (slot->pin == NULL) {

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

            asprintf(&str, "PIN code for %s: ", slot->name);
            prompt.prompt = str;
            prompt.type = HX509_PROMPT_TYPE_PASSWORD;
            prompt.reply.data = pin;
            prompt.reply.length = sizeof(pin);

            ret = hx509_lock_prompt(lock, &prompt);
            if (ret) {
                free(str);
                if (context)
                    hx509_set_error_string(context, 0, ret,
                                           "Failed to get pin code for slot "
                                           "id %d with error: %d",
                                           (int)slot->id, ret);
                return ret;
            }
            free(str);
        } else {
            strlcpy(pin, slot->pin, sizeof(pin));
        }

        ret = P11FUNC(p, Login, (slot->session, CKU_USER,
                                 (unsigned char*)pin, strlen(pin)));
        if (ret != CKR_OK) {
            if (context)
                hx509_set_error_string(context, 0, HX509_PKCS11_LOGIN,
                                       "Failed to login on slot id %d "
                                       "with error: 0x%08x",
                                       (int)slot->id, ret);
            return HX509_PKCS11_LOGIN;
        } else
            slot->flags |= P11_LOGIN_DONE;

        if (slot->pin == NULL) {
            slot->pin = strdup(pin);
            if (slot->pin == NULL) {
                if (context)
                    hx509_set_error_string(context, 0, ENOMEM,
                                           "out of memory");
                return ENOMEM;
            }
        }
    } else
        slot->flags |= P11_LOGIN_DONE;

    slot->flags |= P11_SESSION_IN_USE;

    *psession = slot->session;

    return 0;
}

static int
p11_put_session(struct p11_module *p,
                struct p11_slot *slot,
                CK_SESSION_HANDLE session)
{
    if ((slot->flags & P11_SESSION_IN_USE) == 0)
        _hx509_abort("slot not in session");
    slot->flags &= ~P11_SESSION_IN_USE;

    return 0;
}

static int
iterate_entries(hx509_context context,
                struct p11_module *p, struct p11_slot *slot,
                CK_SESSION_HANDLE session,
                CK_ATTRIBUTE *search_data, int num_search_data,
                CK_ATTRIBUTE *query, int num_query,
                int (*func)(hx509_context,
                            struct p11_module *, struct p11_slot *,
                            CK_SESSION_HANDLE session,
                            CK_OBJECT_HANDLE object,
                            void *, CK_ATTRIBUTE *, int), void *ptr)
{
    CK_OBJECT_HANDLE object;
    CK_ULONG object_count;
    int ret, ret2, i;

    ret = P11FUNC(p, FindObjectsInit, (session, search_data, num_search_data));
    if (ret != CKR_OK) {
        return -1;
    }
    while (1) {
        ret = P11FUNC(p, FindObjects, (session, &object, 1, &object_count));
        if (ret != CKR_OK) {
            return -1;
        }
        if (object_count == 0)
            break;

        for (i = 0; i < num_query; i++)
            query[i].pValue = NULL;

        ret = P11FUNC(p, GetAttributeValue,
                      (session, object, query, num_query));
        if (ret != CKR_OK) {
            return -1;
        }
        for (i = 0; i < num_query; i++) {
            query[i].pValue = malloc(query[i].ulValueLen);
            if (query[i].pValue == NULL) {
                ret = ENOMEM;
                goto out;
            }
        }
        ret = P11FUNC(p, GetAttributeValue,
                      (session, object, query, num_query));
        if (ret != CKR_OK) {
            ret = -1;
            goto out;
        }

        ret = (*func)(context, p, slot, session, object, ptr, query, num_query);
        if (ret)
            goto out;

        for (i = 0; i < num_query; i++) {
            if (query[i].pValue)
                free(query[i].pValue);
            query[i].pValue = NULL;
        }
    }
 out:

    for (i = 0; i < num_query; i++) {
        if (query[i].pValue)
            free(query[i].pValue);
        query[i].pValue = NULL;
    }

    ret2 = P11FUNC(p, FindObjectsFinal, (session));
    if (ret2 != CKR_OK) {
        return ret2;
    }

    return ret;
}

static BIGNUM *
getattr_bn(struct p11_module *p,
           struct p11_slot *slot,
           CK_SESSION_HANDLE session,
           CK_OBJECT_HANDLE object,
           unsigned int type)
{
    CK_ATTRIBUTE query;
    BIGNUM *bn;
    int ret;

    query.type = type;
    query.pValue = NULL;
    query.ulValueLen = 0;

    ret = P11FUNC(p, GetAttributeValue,
                  (session, object, &query, 1));
    if (ret != CKR_OK)
        return NULL;

    query.pValue = malloc(query.ulValueLen);

    ret = P11FUNC(p, GetAttributeValue,
                  (session, object, &query, 1));
    if (ret != CKR_OK) {
        free(query.pValue);
        return NULL;
    }
    bn = BN_bin2bn(query.pValue, query.ulValueLen, NULL);
    free(query.pValue);

    return bn;
}

static int
collect_private_key(hx509_context context,
                    struct p11_module *p, struct p11_slot *slot,
                    CK_SESSION_HANDLE session,
                    CK_OBJECT_HANDLE object,
                    void *ptr, CK_ATTRIBUTE *query, int num_query)
{
    struct hx509_collector *collector = ptr;
    hx509_private_key key;
    heim_octet_string localKeyId;
    int ret;
    const RSA_METHOD *meth;
    BIGNUM *n, *e;
    RSA *rsa;
    struct p11_rsa *p11rsa;

    localKeyId.data = query[0].pValue;
    localKeyId.length = query[0].ulValueLen;

    ret = hx509_private_key_init(&key, NULL, NULL);
    if (ret)
        return ret;

    rsa = RSA_new();
    if (rsa == NULL)
        _hx509_abort("out of memory");

    /*
     * The exponent and modulus should always be present according to
     * the pkcs11 specification, but some smartcards leaves it out,
     * let ignore any failure to fetch it.
     */
    n = getattr_bn(p, slot, session, object, CKA_MODULUS);
    e = getattr_bn(p, slot, session, object, CKA_PUBLIC_EXPONENT);
    if (RSA_set0_key(rsa, n, e, NULL) != 1) {
        BN_free(n);
        BN_free(e);
        RSA_free(rsa);
        hx509_private_key_free(&key);
        return EINVAL;
    }

    p11rsa = calloc(1, sizeof(*p11rsa));
    if (p11rsa == NULL)
        _hx509_abort("out of memory");

    p11rsa->p = p;
    p11rsa->slot = slot;
    p11rsa->private_key = object;

    if (p->ref == 0)
        _hx509_abort("pkcs11 ref == 0 on alloc");
    p->ref++;
    if (p->ref == UINT_MAX)
        _hx509_abort("pkcs11 ref == UINT_MAX on alloc");

    meth = get_p11_rsa_pkcs1_method();
    if (meth == NULL)
        _hx509_abort("failed to create RSA method");
    RSA_set_method(rsa, meth);
    ret = RSA_set_app_data(rsa, p11rsa);
    if (ret != 1)
        _hx509_abort("RSA_set_app_data");

    hx509_private_key_assign_rsa(key, rsa);

    ret = _hx509_collector_private_key_add(context,
                                           collector,
                                           hx509_signature_rsa(),
                                           key,
                                           NULL,
                                           &localKeyId);

    if (ret) {
        hx509_private_key_free(&key);
        return ret;
    }
    return 0;
}

static void
p11_cert_release(hx509_cert cert, void *ctx)
{
    struct p11_module *p = ctx;
    p11_release_module(p);
}


static int
collect_cert(hx509_context context,
             struct p11_module *p, struct p11_slot *slot,
             CK_SESSION_HANDLE session,
             CK_OBJECT_HANDLE object,
             void *ptr, CK_ATTRIBUTE *query, int num_query)
{
    struct hx509_collector *collector = ptr;
    hx509_cert cert;
    int ret;

    if ((CK_LONG)query[0].ulValueLen == -1 ||
        (CK_LONG)query[1].ulValueLen == -1)
    {
        return 0;
    }

    ret = hx509_cert_init_data(context, query[1].pValue,
                               query[1].ulValueLen, &cert);
    if (ret)
        return ret;

    if (p->ref == 0)
        _hx509_abort("pkcs11 ref == 0 on alloc");
    p->ref++;
    if (p->ref == UINT_MAX)
        _hx509_abort("pkcs11 ref to high");

    _hx509_cert_set_release(cert, p11_cert_release, p);

    {
        heim_octet_string data;

        data.data = query[0].pValue;
        data.length = query[0].ulValueLen;

        _hx509_set_cert_attribute(context,
                                  cert,
                                  &asn1_oid_id_pkcs_9_at_localKeyId,
                                  &data);
    }

    if ((CK_LONG)query[2].ulValueLen != -1) {
        char *str;

        asprintf(&str, "%.*s",
                 (int)query[2].ulValueLen, (char *)query[2].pValue);
        if (str) {
            hx509_cert_set_friendly_name(cert, str);
            free(str);
        }
    }

    ret = _hx509_collector_certs_add(context, collector, cert);
    hx509_cert_free(cert);

    return ret;
}


static int
p11_list_keys(hx509_context context,
              struct p11_module *p,
              struct p11_slot *slot,
              CK_SESSION_HANDLE session,
              hx509_lock lock,
              hx509_certs *certs)
{
    struct hx509_collector *collector;
    CK_OBJECT_CLASS key_class;
    CK_ATTRIBUTE search_data[] = {
        {CKA_CLASS, NULL, 0},
    };
    CK_ATTRIBUTE query_data[3] = {
        {CKA_ID, NULL, 0},
        {CKA_VALUE, NULL, 0},
        {CKA_LABEL, NULL, 0}
    };
    int ret;

    search_data[0].pValue = &key_class;
    search_data[0].ulValueLen = sizeof(key_class);

    if (lock == NULL)
        lock = _hx509_empty_lock;

    ret = _hx509_collector_alloc(context, lock, &collector);
    if (ret)
        return ret;

    key_class = CKO_PRIVATE_KEY;
    ret = iterate_entries(context, p, slot, session,
                          search_data, 1,
                          query_data, 1,
                          collect_private_key, collector);
    if (ret)
        goto out;

    key_class = CKO_CERTIFICATE;
    ret = iterate_entries(context, p, slot, session,
                          search_data, 1,
                          query_data, 3,
                          collect_cert, collector);
    if (ret)
        goto out;

    ret = _hx509_collector_collect_certs(context, collector, &slot->certs);

out:
    _hx509_collector_free(collector);

    return ret;
}


static int
p11_init(hx509_context context,
         hx509_certs certs, void **data, int flags,
         const char *residue, hx509_lock lock)
{
    CK_C_GetFunctionList getFuncs;
    struct p11_module *p;
    char *list, *str;
    int ret;

    *data = NULL;

    list = strdup(residue);
    if (list == NULL)
        return ENOMEM;

    p = calloc(1, sizeof(*p));
    if (p == NULL) {
        free(list);
        return ENOMEM;
    }

    p->ref = 1;

    str = strchr(list, ',');
    if (str)
        *str++ = '\0';
    while (str) {
        char *strnext;
        strnext = strchr(str, ',');
        if (strnext)
            *strnext++ = '\0';
#if 0
        if (strncasecmp(str, "slot=", 5) == 0)
            p->selected_slot = atoi(str + 5);
#endif
        str = strnext;
    }

    p->dl_handle = dlopen(list, RTLD_NOW);
    free(list);
    if (p->dl_handle == NULL) {
        ret = HX509_PKCS11_LOAD;
        hx509_set_error_string(context, 0, ret,
                               "Failed to open %s: %s", list, dlerror());
        goto out;
    }

    getFuncs = (CK_C_GetFunctionList) dlsym(p->dl_handle, "C_GetFunctionList");
    if (getFuncs == NULL) {
        ret = HX509_PKCS11_LOAD;
        hx509_set_error_string(context, 0, ret,
                               "C_GetFunctionList missing in %s: %s",
                               list, dlerror());
        goto out;
    }

    ret = (*getFuncs)(&p->funcs);
    if (ret) {
        ret = HX509_PKCS11_LOAD;
        hx509_set_error_string(context, 0, ret,
                               "C_GetFunctionList failed in %s", list);
        goto out;
    }

    ret = P11FUNC(p, Initialize, (NULL_PTR));
    if (ret != CKR_OK) {
        ret = HX509_PKCS11_TOKEN_CONFUSED;
        hx509_set_error_string(context, 0, ret,
                               "Failed initialize the PKCS11 module");
        goto out;
    }

    ret = P11FUNC(p, GetSlotList, (FALSE, NULL, &p->num_slots));
    if (ret) {
        ret = HX509_PKCS11_TOKEN_CONFUSED;
        hx509_set_error_string(context, 0, ret,
                               "Failed to get number of PKCS11 slots");
        goto out;
    }

   if (p->num_slots == 0) {
        ret = HX509_PKCS11_NO_SLOT;
        hx509_set_error_string(context, 0, ret,
                               "Selected PKCS11 module have no slots");
        goto out;
   }


    {
        CK_SLOT_ID_PTR slot_ids;
        int num_tokens = 0;
        size_t i;

        slot_ids = malloc(p->num_slots * sizeof(*slot_ids));
        if (slot_ids == NULL) {
            hx509_clear_error_string(context);
            ret = ENOMEM;
            goto out;
        }

        ret = P11FUNC(p, GetSlotList, (FALSE, slot_ids, &p->num_slots));
        if (ret) {
            free(slot_ids);
            hx509_set_error_string(context, 0, HX509_PKCS11_TOKEN_CONFUSED,
                                   "Failed getting slot-list from "
                                   "PKCS11 module");
            ret = HX509_PKCS11_TOKEN_CONFUSED;
            goto out;
        }

        p->slot = calloc(p->num_slots, sizeof(p->slot[0]));
        if (p->slot == NULL) {
            free(slot_ids);
            hx509_set_error_string(context, 0, ENOMEM,
                                   "Failed to get memory for slot-list");
            ret = ENOMEM;
            goto out;
        }

        for (i = 0; i < p->num_slots; i++) {
            ret = p11_init_slot(context, p, lock, slot_ids[i], i, &p->slot[i]);
            if (ret)
                break;
            if (p->slot[i].flags & P11_TOKEN_PRESENT)
                num_tokens++;
        }
        free(slot_ids);
        if (ret)
            goto out;
        if (num_tokens == 0) {
            ret = HX509_PKCS11_NO_TOKEN;
            goto out;
        }
    }

    *data = p;

    return 0;
 out:
    p11_release_module(p);
    return ret;
}

static void
p11_release_module(struct p11_module *p)
{
    size_t i;

    if (p->ref == 0)
        _hx509_abort("pkcs11 ref to low");
    if (--p->ref > 0)
        return;

    for (i = 0; i < p->num_slots; i++) {
        if (p->slot[i].flags & P11_SESSION_IN_USE)
            _hx509_abort("pkcs11 module release while session in use");
        if (p->slot[i].flags & P11_SESSION) {
            P11FUNC(p, CloseSession, (p->slot[i].session));
        }

        if (p->slot[i].name)
            free(p->slot[i].name);
        if (p->slot[i].pin) {
            memset(p->slot[i].pin, 0, strlen(p->slot[i].pin));
            free(p->slot[i].pin);
        }
        if (p->slot[i].mechs.num) {
            free(p->slot[i].mechs.list);

            if (p->slot[i].mechs.infos) {
                size_t j;

                for (j = 0 ; j < p->slot[i].mechs.num ; j++)
                    free(p->slot[i].mechs.infos[j]);
                free(p->slot[i].mechs.infos);
            }
        }
    }
    free(p->slot);

    if (p->funcs)
        P11FUNC(p, Finalize, (NULL));

    if (p->dl_handle)
        dlclose(p->dl_handle);

    memset(p, 0, sizeof(*p));
    free(p);
}

static int
p11_free(hx509_certs certs, void *data)
{
    struct p11_module *p = data;
    size_t i;

    for (i = 0; i < p->num_slots; i++) {
        if (p->slot[i].certs)
            hx509_certs_free(&p->slot[i].certs);
    }
    p11_release_module(p);
    return 0;
}

struct p11_cursor {
    hx509_certs certs;
    void *cursor;
};

static int
p11_iter_start(hx509_context context,
               hx509_certs certs, void *data, void **cursor)
{
    struct p11_module *p = data;
    struct p11_cursor *c;
    int ret;
    size_t i;

    c = malloc(sizeof(*c));
    if (c == NULL) {
        hx509_clear_error_string(context);
        return ENOMEM;
    }
    ret = hx509_certs_init(context, "MEMORY:pkcs11-iter", 0, NULL, &c->certs);
    if (ret) {
        free(c);
        return ret;
    }

    for (i = 0 ; i < p->num_slots; i++) {
        if (p->slot[i].certs == NULL)
            continue;
        ret = hx509_certs_merge(context, c->certs, p->slot[i].certs);
        if (ret) {
            hx509_certs_free(&c->certs);
            free(c);
            return ret;
        }
    }

    ret = hx509_certs_start_seq(context, c->certs, &c->cursor);
    if (ret) {
        hx509_certs_free(&c->certs);
        free(c);
        return 0;
    }
    *cursor = c;

    return 0;
}

static int
p11_iter(hx509_context context,
         hx509_certs certs, void *data, void *cursor, hx509_cert *cert)
{
    struct p11_cursor *c = cursor;
    return hx509_certs_next_cert(context, c->certs, c->cursor, cert);
}

static int
p11_iter_end(hx509_context context,
             hx509_certs certs, void *data, void *cursor)
{
    struct p11_cursor *c = cursor;
    int ret;
    ret = hx509_certs_end_seq(context, c->certs, c->cursor);
    hx509_certs_free(&c->certs);
    free(c);
    return ret;
}

#define MECHFLAG(x) { "unknown-flag-" #x, x }
static struct units mechflags[] = {
        MECHFLAG(0x80000000),
        MECHFLAG(0x40000000),
        MECHFLAG(0x20000000),
        MECHFLAG(0x10000000),
        MECHFLAG(0x08000000),
        MECHFLAG(0x04000000),
        {"ec-compress",         0x2000000 },
        {"ec-uncompress",       0x1000000 },
        {"ec-namedcurve",       0x0800000 },
        {"ec-ecparameters",     0x0400000 },
        {"ec-f-2m",             0x0200000 },
        {"ec-f-p",              0x0100000 },
        {"derive",              0x0080000 },
        {"unwrap",              0x0040000 },
        {"wrap",                0x0020000 },
        {"genereate-key-pair",  0x0010000 },
        {"generate",            0x0008000 },
        {"verify-recover",      0x0004000 },
        {"verify",              0x0002000 },
        {"sign-recover",        0x0001000 },
        {"sign",                0x0000800 },
        {"digest",              0x0000400 },
        {"decrypt",             0x0000200 },
        {"encrypt",             0x0000100 },
        MECHFLAG(0x00080),
        MECHFLAG(0x00040),
        MECHFLAG(0x00020),
        MECHFLAG(0x00010),
        MECHFLAG(0x00008),
        MECHFLAG(0x00004),
        MECHFLAG(0x00002),
        {"hw",                  0x0000001 },
        { NULL,                 0x0000000 }
};
#undef MECHFLAG

static int
p11_printinfo(hx509_context context,
              hx509_certs certs,
              void *data,
              int (*func)(void *, const char *),
              void *ctx)
{
    struct p11_module *p = data;
    size_t i, j;

    _hx509_pi_printf(func, ctx, "pkcs11 driver with %d slot%s",
                     p->num_slots, p->num_slots > 1 ? "s" : "");

    for (i = 0; i < p->num_slots; i++) {
        struct p11_slot *s = &p->slot[i];

        _hx509_pi_printf(func, ctx, "slot %d: id: %d name: %s flags: %08x",
                         i, (int)s->id, s->name, s->flags);

        _hx509_pi_printf(func, ctx, "number of supported mechanisms: %lu",
                         (unsigned long)s->mechs.num);
        for (j = 0; j < s->mechs.num; j++) {
            const char *mechname = "unknown";
            char flags[256], unknownname[40];
#define MECHNAME(s,n) case s: mechname = n; break
            switch(s->mechs.list[j]) {
                MECHNAME(CKM_RSA_PKCS_KEY_PAIR_GEN, "rsa-pkcs-key-pair-gen");
                MECHNAME(CKM_RSA_PKCS, "rsa-pkcs");
                MECHNAME(CKM_RSA_X_509, "rsa-x-509");
                MECHNAME(CKM_MD5_RSA_PKCS, "md5-rsa-pkcs");
                MECHNAME(CKM_SHA1_RSA_PKCS, "sha1-rsa-pkcs");
                MECHNAME(CKM_SHA256_RSA_PKCS, "sha256-rsa-pkcs");
                MECHNAME(CKM_SHA384_RSA_PKCS, "sha384-rsa-pkcs");
                MECHNAME(CKM_SHA512_RSA_PKCS, "sha512-rsa-pkcs");
                MECHNAME(CKM_RIPEMD160_RSA_PKCS, "ripemd160-rsa-pkcs");
                MECHNAME(CKM_RSA_PKCS_OAEP, "rsa-pkcs-oaep");
                MECHNAME(CKM_SHA512_HMAC, "sha512-hmac");
                MECHNAME(CKM_SHA512, "sha512");
                MECHNAME(CKM_SHA384_HMAC, "sha384-hmac");
                MECHNAME(CKM_SHA384, "sha384");
                MECHNAME(CKM_SHA256_HMAC, "sha256-hmac");
                MECHNAME(CKM_SHA256, "sha256");
                MECHNAME(CKM_SHA_1, "sha1");
                MECHNAME(CKM_MD5, "md5");
                MECHNAME(CKM_RIPEMD160, "ripemd-160");
                MECHNAME(CKM_DES_ECB, "des-ecb");
                MECHNAME(CKM_DES_CBC, "des-cbc");
                MECHNAME(CKM_AES_ECB, "aes-ecb");
                MECHNAME(CKM_AES_CBC, "aes-cbc");
                MECHNAME(CKM_DH_PKCS_PARAMETER_GEN, "dh-pkcs-parameter-gen");
            default:
                snprintf(unknownname, sizeof(unknownname),
                         "unknown-mech-%lu",
                         (unsigned long)s->mechs.list[j]);
                mechname = unknownname;
                break;
            }
#undef MECHNAME
            unparse_flags(s->mechs.infos[j]->flags, mechflags,
                          flags, sizeof(flags));

            _hx509_pi_printf(func, ctx, "  %s: %s", mechname, flags);
        }
    }

    return 0;
}

static struct hx509_keyset_ops keyset_pkcs11 = {
    "PKCS11",
    0,
    p11_init,
    NULL,
    p11_free,
    NULL,
    NULL,
    p11_iter_start,
    p11_iter,
    p11_iter_end,
    p11_printinfo
};

#endif /* HAVE_DLOPEN */

void
_hx509_ks_pkcs11_register(hx509_context context)
{
#ifdef HAVE_DLOPEN
    _hx509_ks_register(context, &keyset_pkcs11);
#endif
}