/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/gssapi/krb5/naming_exts.c */
/*
 * Copyright 2009 by the Massachusetts Institute of Technology.
 * All Rights Reserved.
 *
 * Export of this software from the United States of America may
 *   require a specific license from the United States Government.
 *   It is the responsibility of any person or organization contemplating
 *   export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  Furthermore if you modify this software you must label
 * your software as modified software and not distribute it in such a
 * fashion that it might be confused with the original M.I.T. software.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 */

#include <assert.h>
#include "k5-int.h"          /* for zap() */
#include "gssapiP_krb5.h"
#include <stdarg.h>

krb5_error_code
kg_init_name(krb5_context context, krb5_principal principal,
             char *service, char *host, krb5_authdata_context ad_context,
             krb5_flags flags, krb5_gss_name_t *ret_name)
{
    krb5_error_code code;
    krb5_gss_name_t name;

    *ret_name = NULL;

    assert(principal != NULL);

    if (principal == NULL)
        return EINVAL;

    name = xmalloc(sizeof(krb5_gss_name_rec));
    if (name == NULL)
        return ENOMEM;

    memset(name, 0, sizeof(krb5_gss_name_rec));

    code = k5_mutex_init(&name->lock);
    if (code != 0)
        goto cleanup;

    if ((flags & KG_INIT_NAME_NO_COPY) == 0) {
        code = krb5_copy_principal(context, principal, &name->princ);
        if (code != 0)
            goto cleanup;

        if (ad_context != NULL) {
            code = krb5_authdata_context_copy(context,
                                              ad_context,
                                              &name->ad_context);
            if (code != 0)
                goto cleanup;
        }

        code = ENOMEM;
        if (service != NULL) {
            name->service = strdup(service);
            if (name->service == NULL)
                goto cleanup;
        }
        if (host != NULL) {
            name->host = strdup(host);
            if (name->host == NULL)
                goto cleanup;
        }
        code = 0;
    } else {
        name->princ = principal;
        name->service = service;
        name->host = host;
        name->ad_context = ad_context;
    }

    *ret_name = name;

cleanup:
    if (code != 0)
        kg_release_name(context, &name);

    return code;
}

krb5_error_code
kg_release_name(krb5_context context,
                krb5_gss_name_t *name)
{
    if (*name != NULL) {
        krb5_free_principal(context, (*name)->princ);
        free((*name)->service);
        free((*name)->host);
        krb5_authdata_context_free(context, (*name)->ad_context);
        k5_mutex_destroy(&(*name)->lock);
        free(*name);
        *name = NULL;
    }

    return 0;
}

krb5_error_code
kg_duplicate_name(krb5_context context,
                  const krb5_gss_name_t src,
                  krb5_gss_name_t *dst)
{
    krb5_error_code code;

    k5_mutex_lock(&src->lock);
    code = kg_init_name(context, src->princ, src->service, src->host,
                        src->ad_context, 0, dst);
    k5_mutex_unlock(&src->lock);
    return code;
}


krb5_boolean
kg_compare_name(krb5_context context,
                krb5_gss_name_t name1,
                krb5_gss_name_t name2)
{
    return krb5_principal_compare(context, name1->princ, name2->princ);
}

/* Determine the principal to use for an acceptor name, which is different from
 * name->princ for host-based names. */
krb5_boolean
kg_acceptor_princ(krb5_context context, krb5_gss_name_t name,
                  krb5_principal *princ_out)
{
    krb5_error_code code;
    const char *host;
    char *tmp = NULL;

    *princ_out = NULL;
    if (name == NULL)
        return 0;

    /* If it's not a host-based name, just copy name->princ. */
    if (name->service == NULL)
        return krb5_copy_principal(context, name->princ, princ_out);

    if (name->host != NULL && name->princ->length == 2) {
        /* If a host was given, we have to use the canonicalized form of it (as
         * given by krb5_sname_to_principal) for backward compatibility. */
        const krb5_data *d = &name->princ->data[1];
        tmp = k5memdup0(d->data, d->length, &code);
        if (tmp == NULL)
            return ENOMEM;
        host = tmp;
    } else                      /* No host was given; use an empty string. */
        host = "";

    code = krb5_build_principal(context, princ_out, 0, "", name->service, host,
                                (char *)NULL);
    if (*princ_out != NULL)
        (*princ_out)->type = KRB5_NT_SRV_HST;
    free(tmp);
    return code;
}

static OM_uint32
kg_map_name_error(OM_uint32 *minor_status, krb5_error_code code)
{
    OM_uint32 major_status;

    switch (code) {
    case 0:
        major_status = GSS_S_COMPLETE;
        break;
    case ENOENT:
    case EPERM:
        major_status = GSS_S_UNAVAILABLE;
        break;
    default:
        major_status = GSS_S_FAILURE;
        break;
    }

    *minor_status = code;

    return major_status;
}

/* Owns data on success */
static krb5_error_code
data_list_to_buffer_set(krb5_context context,
                        krb5_data *data,
                        gss_buffer_set_t *buffer_set)
{
    gss_buffer_set_t set = GSS_C_NO_BUFFER_SET;
    OM_uint32 minor_status;
    int i;
    krb5_error_code code = 0;

    if (data == NULL)
        goto cleanup;

    if (buffer_set == NULL)
        goto cleanup;

    if (GSS_ERROR(gss_create_empty_buffer_set(&minor_status,
                                              &set))) {
        assert(minor_status != 0);
        code = minor_status;
        goto cleanup;
    }

    for (i = 0; data[i].data != NULL; i++)
        ;

    set->count = i;
    set->elements = gssalloc_calloc(i, sizeof(gss_buffer_desc));
    if (set->elements == NULL) {
        gss_release_buffer_set(&minor_status, &set);
        code = ENOMEM;
        goto cleanup;
    }

    /*
     * Copy last element first so data remains properly
     * NULL-terminated in case of allocation failure
     * in data_to_gss() on windows.
     */
    for (i = set->count-1; i >= 0; i--) {
        if (data_to_gss(&data[i], &set->elements[i])) {
            gss_release_buffer_set(&minor_status, &set);
            code = ENOMEM;
            goto cleanup;
        }
    }
cleanup:
    krb5int_free_data_list(context, data);

    if (buffer_set != NULL)
        *buffer_set = set;

    return code;
}

OM_uint32 KRB5_CALLCONV
krb5_gss_inquire_name(OM_uint32 *minor_status,
                      gss_name_t name,
                      int *name_is_MN,
                      gss_OID *MN_mech,
                      gss_buffer_set_t *attrs)
{
    krb5_context context;
    krb5_error_code code;
    krb5_gss_name_t kname;
    krb5_data *kattrs = NULL;

    if (minor_status != NULL)
        *minor_status = 0;

    if (attrs != NULL)
        *attrs = GSS_C_NO_BUFFER_SET;

    code = krb5_gss_init_context(&context);
    if (code != 0) {
        *minor_status = code;
        return GSS_S_FAILURE;
    }

    kname = (krb5_gss_name_t)name;

    k5_mutex_lock(&kname->lock);

    if (kname->ad_context == NULL) {
        code = krb5_authdata_context_init(context, &kname->ad_context);
        if (code != 0)
            goto cleanup;
    }

    code = krb5_authdata_get_attribute_types(context,
                                             kname->ad_context,
                                             &kattrs);
    if (code != 0)
        goto cleanup;

    code = data_list_to_buffer_set(context, kattrs, attrs);
    kattrs = NULL;
    if (code != 0)
        goto cleanup;

cleanup:
    k5_mutex_unlock(&kname->lock);
    krb5int_free_data_list(context, kattrs);

    krb5_free_context(context);

    return kg_map_name_error(minor_status, code);
}

OM_uint32 KRB5_CALLCONV
krb5_gss_get_name_attribute(OM_uint32 *minor_status,
                            gss_name_t name,
                            gss_buffer_t attr,
                            int *authenticated,
                            int *complete,
                            gss_buffer_t value,
                            gss_buffer_t display_value,
                            int *more)
{
    krb5_context context;
    krb5_error_code code;
    krb5_gss_name_t kname;
    krb5_data kattr;
    krb5_boolean kauthenticated;
    krb5_boolean kcomplete;
    krb5_data kvalue;
    krb5_data kdisplay_value;

    if (minor_status != NULL)
        *minor_status = 0;

    code = krb5_gss_init_context(&context);
    if (code != 0) {
        *minor_status = code;
        return GSS_S_FAILURE;
    }

    kname = (krb5_gss_name_t)name;
    k5_mutex_lock(&kname->lock);

    if (kname->ad_context == NULL) {
        code = krb5_authdata_context_init(context, &kname->ad_context);
        if (code != 0) {
            *minor_status = code;
            k5_mutex_unlock(&kname->lock);
            krb5_free_context(context);
            return GSS_S_UNAVAILABLE;
        }
    }

    kattr.data = (char *)attr->value;
    kattr.length = attr->length;

    kauthenticated = FALSE;
    kcomplete = FALSE;

    code = krb5_authdata_get_attribute(context,
                                       kname->ad_context,
                                       &kattr,
                                       &kauthenticated,
                                       &kcomplete,
                                       value ? &kvalue : NULL,
                                       display_value ? &kdisplay_value : NULL,
                                       more);
    if (code == 0) {
        if (value != NULL)
            code = data_to_gss(&kvalue, value);

        if (authenticated != NULL)
            *authenticated = kauthenticated;
        if (complete != NULL)
            *complete = kcomplete;

        if (display_value != NULL) {
            if (code == 0)
                code = data_to_gss(&kdisplay_value, display_value);
            else
                free(kdisplay_value.data);
        }
    }

    k5_mutex_unlock(&kname->lock);
    krb5_free_context(context);

    return kg_map_name_error(minor_status, code);
}

OM_uint32 KRB5_CALLCONV
krb5_gss_set_name_attribute(OM_uint32 *minor_status,
                            gss_name_t name,
                            int complete,
                            gss_buffer_t attr,
                            gss_buffer_t value)
{
    krb5_context context;
    krb5_error_code code;
    krb5_gss_name_t kname;
    krb5_data kattr;
    krb5_data kvalue;

    if (minor_status != NULL)
        *minor_status = 0;

    code = krb5_gss_init_context(&context);
    if (code != 0) {
        *minor_status = code;
        return GSS_S_FAILURE;
    }

    kname = (krb5_gss_name_t)name;
    k5_mutex_lock(&kname->lock);

    if (kname->ad_context == NULL) {
        code = krb5_authdata_context_init(context, &kname->ad_context);
        if (code != 0) {
            *minor_status = code;
            k5_mutex_unlock(&kname->lock);
            krb5_free_context(context);
            return GSS_S_UNAVAILABLE;
        }
    }

    kattr.data = (char *)attr->value;
    kattr.length = attr->length;

    kvalue.data = (char *)value->value;
    kvalue.length = value->length;

    code = krb5_authdata_set_attribute(context,
                                       kname->ad_context,
                                       complete,
                                       &kattr,
                                       &kvalue);

    k5_mutex_unlock(&kname->lock);
    krb5_free_context(context);

    return kg_map_name_error(minor_status, code);
}

OM_uint32 KRB5_CALLCONV
krb5_gss_delete_name_attribute(OM_uint32 *minor_status,
                               gss_name_t name,
                               gss_buffer_t attr)
{
    krb5_context context;
    krb5_error_code code;
    krb5_gss_name_t kname;
    krb5_data kattr;

    if (minor_status != NULL)
        *minor_status = 0;

    code = krb5_gss_init_context(&context);
    if (code != 0) {
        *minor_status = code;
        return GSS_S_FAILURE;
    }

    kname = (krb5_gss_name_t)name;
    k5_mutex_lock(&kname->lock);

    if (kname->ad_context == NULL) {
        code = krb5_authdata_context_init(context, &kname->ad_context);
        if (code != 0) {
            *minor_status = code;
            k5_mutex_unlock(&kname->lock);
            krb5_free_context(context);
            return GSS_S_UNAVAILABLE;
        }
    }

    kattr.data = (char *)attr->value;
    kattr.length = attr->length;

    code = krb5_authdata_delete_attribute(context,
                                          kname->ad_context,
                                          &kattr);

    k5_mutex_unlock(&kname->lock);
    krb5_free_context(context);

    return kg_map_name_error(minor_status, code);
}

OM_uint32 KRB5_CALLCONV
krb5_gss_map_name_to_any(OM_uint32 *minor_status,
                         gss_name_t name,
                         int authenticated,
                         gss_buffer_t type_id,
                         gss_any_t *output)
{
    krb5_context context;
    krb5_error_code code;
    krb5_gss_name_t kname;
    char *kmodule;

    if (minor_status != NULL)
        *minor_status = 0;

    code = krb5_gss_init_context(&context);
    if (code != 0) {
        *minor_status = code;
        return GSS_S_FAILURE;
    }

    kname = (krb5_gss_name_t)name;
    k5_mutex_lock(&kname->lock);

    if (kname->ad_context == NULL) {
        code = krb5_authdata_context_init(context, &kname->ad_context);
        if (code != 0) {
            *minor_status = code;
            k5_mutex_unlock(&kname->lock);
            krb5_free_context(context);
            return GSS_S_UNAVAILABLE;
        }
    }

    kmodule = (char *)type_id->value;
    if (kmodule[type_id->length] != '\0') {
        k5_mutex_unlock(&kname->lock);
        krb5_free_context(context);
        return GSS_S_UNAVAILABLE;
    }

    code = krb5_authdata_export_internal(context,
                                         kname->ad_context,
                                         authenticated,
                                         kmodule,
                                         (void **)output);

    k5_mutex_unlock(&kname->lock);
    krb5_free_context(context);

    return kg_map_name_error(minor_status, code);
}

OM_uint32 KRB5_CALLCONV
krb5_gss_release_any_name_mapping(OM_uint32 *minor_status,
                                  gss_name_t name,
                                  gss_buffer_t type_id,
                                  gss_any_t *input)
{
    krb5_context context;
    krb5_error_code code;
    krb5_gss_name_t kname;
    char *kmodule;

    if (minor_status != NULL)
        *minor_status = 0;

    code = krb5_gss_init_context(&context);
    if (code != 0) {
        *minor_status = code;
        return GSS_S_FAILURE;
    }

    kname = (krb5_gss_name_t)name;
    k5_mutex_lock(&kname->lock);

    if (kname->ad_context == NULL) {
        code = krb5_authdata_context_init(context, &kname->ad_context);
        if (code != 0) {
            *minor_status = code;
            k5_mutex_unlock(&kname->lock);
            krb5_free_context(context);
            return GSS_S_UNAVAILABLE;
        }
    }

    kmodule = (char *)type_id->value;
    if (kmodule[type_id->length] != '\0') {
        k5_mutex_unlock(&kname->lock);
        krb5_free_context(context);
        return GSS_S_UNAVAILABLE;
    }

    code = krb5_authdata_free_internal(context,
                                       kname->ad_context,
                                       kmodule,
                                       *input);
    if (code == 0)
        *input = NULL;

    k5_mutex_unlock(&kname->lock);
    krb5_free_context(context);

    return kg_map_name_error(minor_status, code);

}

OM_uint32 KRB5_CALLCONV
krb5_gss_export_name_composite(OM_uint32 *minor_status,
                               gss_name_t name,
                               gss_buffer_t exp_composite_name)
{
    krb5_context context;
    krb5_error_code code;
    krb5_gss_name_t kname;
    krb5_data *attrs = NULL;
    char *princstr = NULL;
    unsigned char *cp;
    size_t princlen;

    if (minor_status != NULL)
        *minor_status = 0;

    code = krb5_gss_init_context(&context);
    if (code != 0) {
        *minor_status = code;
        return GSS_S_FAILURE;
    }

    kname = (krb5_gss_name_t)name;
    k5_mutex_lock(&kname->lock);

    code = krb5_unparse_name(context, kname->princ, &princstr);
    if (code != 0)
        goto cleanup;

    princlen = strlen(princstr);

    if (kname->ad_context != NULL) {
        code = krb5_authdata_export_attributes(context,
                                               kname->ad_context,
                                               AD_USAGE_MASK,
                                               &attrs);
        if (code != 0)
            goto cleanup;
    }

    /* 04 02 OID Name AuthData */

    exp_composite_name->length = 10 + gss_mech_krb5->length + princlen;
    exp_composite_name->length += 4; /* length of encoded attributes */
    if (attrs != NULL)
        exp_composite_name->length += attrs->length;
    exp_composite_name->value = malloc(exp_composite_name->length);
    if (exp_composite_name->value == NULL) {
        code = ENOMEM;
        goto cleanup;
    }

    cp = exp_composite_name->value;

    /* Note: we assume the OID will be less than 128 bytes... */
    *cp++ = 0x04;
    *cp++ = 0x02;

    store_16_be(gss_mech_krb5->length + 2, cp);
    cp += 2;
    *cp++ = 0x06;
    *cp++ = (gss_mech_krb5->length) & 0xFF;
    memcpy(cp, gss_mech_krb5->elements, gss_mech_krb5->length);
    cp += gss_mech_krb5->length;

    store_32_be(princlen, cp);
    cp += 4;
    memcpy(cp, princstr, princlen);
    cp += princlen;

    store_32_be(attrs != NULL ? attrs->length : 0, cp);
    cp += 4;

    if (attrs != NULL) {
        memcpy(cp, attrs->data, attrs->length);
        cp += attrs->length;
    }

cleanup:
    krb5_free_unparsed_name(context, princstr);
    krb5_free_data(context, attrs);
    k5_mutex_unlock(&kname->lock);
    krb5_free_context(context);

    return kg_map_name_error(minor_status, code);
}

#if 0
OM_uint32
krb5_gss_display_name_ext(OM_uint32 *minor_status,
                          gss_name_t name,
                          gss_OID display_as_name_type,
                          gss_buffer_t display_name)
{
}
#endif