libidav/resource.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2018 Olaf Wintermann. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <libxml/tree.h>

#include "utils.h"
#include "session.h"
#include "methods.h"
#include "crypto.h"
#include "ucx/buffer.h"
#include "ucx/utils.h"

#include "resource.h"
#include "xml.h"
#include "davqlexec.h"

#define xstreq(a,b) xmlStrEqual(BAD_CAST a, BAD_CAST b)

DavResource* dav_resource_new(DavSession *sn, char *path) {
    //char *href = util_url_path(url);
    //DavResource *res = dav_resource_new_href(sn, href);
    char *parent = util_parent_path(path);
    char *name = util_resource_name(path); 
    char *href = dav_session_create_plain_href(sn, path);
    
    DavResource *res = dav_resource_new_full(sn, parent, name, href);
    free(parent);
    return res;
}

DavResource* dav_resource_new_child(DavSession *sn, DavResource *parent, char *name) {
    char *path = util_concat_path(parent->path, name);
    char *href = dav_session_create_plain_href(sn, path);
    DavResource *res = dav_resource_new_full(sn, parent->path, name, href);
    free(path);
    return res;
}


DavResource* dav_resource_new_href(DavSession *sn, char *href) {  
    DavResource *res = ucx_mempool_calloc(sn->mp, 1, sizeof(DavResource));
    res->session = sn;
    
    // set name, path and href
    resource_set_info(res, href);
    
    // initialize resource data
    res->data = resource_data_new(sn);
    
    return res;
}

DavResource* dav_resource_new_full(DavSession *sn, char *parent_path, char *name, char *href) {
    sstr_t n = sstr(name);
    // the name must not contain path separators
    if(n.length > 0 && href) {
        for(int i=0;i<n.length-1;i++) {
            char c = n.ptr[i];
            if(c == '/' || c == '\\') {
                n = sstr(util_resource_name(href));
                break;
            }
        }
    }
    // remove trailing '/'
    if(n.length > 0 && n.ptr[n.length-1] == '/') {
        n.length--;
    }
    
    DavResource *res = ucx_mempool_calloc(sn->mp, 1, sizeof(DavResource));
    res->session = sn;
    
    // set name, path and href
    res->name = sstrdup_a(sn->mp->allocator, n).ptr;
    
    char *path = util_concat_path(parent_path, name); 
    res->path = dav_session_strdup(sn, path);
    
    res->href = href;
    
    // initialize resource data
    res->data = resource_data_new(sn);
    
    // cache href/path
    if(href) {
        dav_session_cache_path(sn, sstr(path), sstr(href));
    }
    free(path);
    
    return res;
}

void resource_free_properties(DavSession *sn, UcxMap *properties) {
    if(!properties) return;
    
    UcxMapIterator i = ucx_map_iterator(properties);
    DavProperty *property;
    UCX_MAP_FOREACH(key, property, i) {
        // TODO: free everything
        dav_session_free(sn, property);
    }
    ucx_map_free(properties);
}

void dav_resource_free(DavResource *res) {
    DavSession *sn = res->session;
    
    dav_session_free(sn, res->name);
    dav_session_free(sn, res->path);
    if(res->href) {
        dav_session_free(sn, res->href);
    }
    
    DavResourceData *data = res->data;
    resource_free_properties(sn, data->properties);
    resource_free_properties(sn, data->crypto_properties);
    
    UCX_FOREACH(elm, data->set) {
        DavProperty *p = elm->data;
        dav_session_free(sn, p->ns->name);
        if(p->ns->prefix) {
            dav_session_free(sn, p->ns->prefix);
        }
        dav_session_free(sn, p->ns);
        
        dav_session_free(sn, p->name);
        dav_free_xml_node_sn(sn, p->value);
        dav_session_free(sn, p);
    }
    
    UCX_FOREACH(elm, data->remove) {
        DavProperty *p = elm->data;
        dav_session_free(sn, p->ns->name);
        if(p->ns->prefix) {
            dav_session_free(sn, p->ns->prefix);
        }
        dav_session_free(sn, p->ns);
        
        dav_session_free(sn, p->name);
        dav_session_free(sn, p);
    }
    
    if(!data->read && data->content) {
        dav_session_free(sn, data->content);
    }
    dav_session_free(sn, data);
    
    dav_session_free(sn, res);
}

void dav_resource_free_all(DavResource *res) {
    DavResource *child = res->children;
    dav_resource_free(res);
    while(child) {
        DavResource *next = child->next;
        dav_resource_free_all(child);
        child = next;
    }
}

void resource_set_href(DavResource *res, sstr_t href) {
    res->href = sstrdup_a(res->session->mp->allocator, href).ptr;
}

void resource_set_info(DavResource *res, char *href_str) {
    char *url_str = NULL;
    curl_easy_getinfo(res->session->handle, CURLINFO_EFFECTIVE_URL, &url_str);
    sstr_t name = sstr(util_resource_name(href_str));
    sstr_t href = sstr(href_str);
    
    sstr_t base_href = sstr(util_url_path(res->session->base_url));
    sstr_t path = sstrsubs(href, base_href.length - 1);
    
    UcxAllocator *a = res->session->mp->allocator;
    CURL *handle = res->session->handle;
    
    int nlen = 0;
    char *uname = curl_easy_unescape(handle, name.ptr, name.length , &nlen);
    int plen = 0;
    char *upath = curl_easy_unescape(handle, path.ptr, path.length, &plen); 
    
    res->name = sstrdup_a(a, sstrn(uname, nlen)).ptr;
    res->href = sstrdup_a(a, href).ptr;
    res->path = sstrdup_a(a, sstrn(upath, plen)).ptr;
    
    curl_free(uname);
    curl_free(upath);
}

DavResourceData* resource_data_new(DavSession *sn) {
    DavResourceData *data = ucx_mempool_malloc(
            sn->mp,
            sizeof(DavResourceData));
    if(!data) {
        return NULL;
    }
    data->properties = ucx_map_new_a(sn->mp->allocator, 32);
    data->crypto_properties = NULL;
    data->set = NULL;
    data->remove = NULL;
    data->crypto_set = NULL;
    data->crypto_remove = NULL;
    data->read = NULL;
    data->content = NULL;
    data->seek = NULL;
    data->length = 0;
    return data;
}

char* dav_resource_get_href(DavResource *resource) {
    if(!resource->href) {
        resource->href = dav_session_get_href(
                resource->session,
                resource->path);
    }
    return resource->href;
}

void resource_add_prop(DavResource *res, const char *ns, const char *name, DavXmlNode *val) {
    DavSession *sn = res->session;
    
    DavNamespace *namespace = dav_session_malloc(sn, sizeof(DavNamespace));
    namespace->prefix = NULL;
    namespace->name = dav_session_strdup(sn, ns);
    
    DavProperty *prop = dav_session_malloc(sn, sizeof(DavProperty));
    prop->name = dav_session_strdup(sn, name);
    prop->ns = namespace;
    prop->value = val;
    
    sstr_t key = dav_property_key(ns, name);
    ucx_map_sstr_put(((DavResourceData*)res->data)->properties, key, prop);
    free(key.ptr);
}

void resource_add_property(DavResource *res, const char *ns, const char *name, xmlNode *val) {
    if(!val) {
        return;
    }
    
    resource_add_prop(res, ns, name, dav_convert_xml(res->session, val));
}

void resource_add_string_property(DavResource *res, char *ns, char *name, char *val) {
    if(!val) {
        return;
    }
    
    resource_add_prop(res, ns, name, dav_text_node(res->session, val));
}

void resource_set_crypto_properties(DavResource *res, UcxMap *cprops) {
    DavResourceData *data = res->data;
    resource_free_properties(res->session, data->crypto_properties);
    data->crypto_properties = cprops;
}

DavXmlNode* resource_get_property(DavResource *res, const char *ns, const char *name) {
    sstr_t keystr = dav_property_key(ns, name);
    UcxKey key = ucx_key(keystr.ptr, keystr.length);
    DavXmlNode *ret = resource_get_property_k(res, key);
    free(keystr.ptr);
    
    return ret;
}

DavXmlNode* resource_get_encrypted_property(DavResource *res, const char *ns, const char *name) {
    sstr_t keystr = dav_property_key(ns, name);
    UcxKey key = ucx_key(keystr.ptr, keystr.length);
    DavXmlNode *ret = resource_get_encrypted_property_k(res, key);
    free(keystr.ptr);
    
    return ret;
}

DavXmlNode* resource_get_property_k(DavResource *res, UcxKey key) {
    DavResourceData *data = (DavResourceData*)res->data;
    DavProperty *property = ucx_map_get(data->properties, key);
    
    return property ? property->value : NULL;
}

DavXmlNode* resource_get_encrypted_property_k(DavResource *res, UcxKey key) {
    DavResourceData *data = (DavResourceData*)res->data;
    DavProperty *property = ucx_map_get(data->crypto_properties, key);
    
    return property ? property->value : NULL;
}

sstr_t dav_property_key(const char *ns, const char *name) {
    return dav_property_key_a(ucx_default_allocator(), ns, name);
}

sstr_t dav_property_key_a(UcxAllocator *a, const char *ns, const char *name) {
    scstr_t ns_str = scstr(ns);
    scstr_t name_str = scstr(name);
    
    return sstrcat_a(a, 4, ns_str, S("\0"), name_str, S("\0"));
}


void resource_add_child(DavResource *parent, DavResource *child) {
    child->next = NULL;
    if(parent->children) {
        DavResource *last = parent->children;
        while(last->next) {
            last = last->next;
        }
        last->next = child;
        child->prev = last;
    } else {
        child->prev = NULL;
        parent->children = child;
    }
    child->parent = parent;
}

static int resource_cmp(DavResource *res1, DavResource *res2, DavOrderCriterion *cr) {
    if(!(res1 && res2)) {
        return 0;
    }
    
    int ret;
    if(cr->type == 0) {
        switch(cr->column.resprop) {
            case DAVQL_RES_NAME: {
                ret = strcmp(res1->name, res2->name);
                break;
            }
            case DAVQL_RES_PATH: {
                ret = strcmp(res1->path, res2->path);
                break;
            }
            case DAVQL_RES_HREF: {
                ret = strcmp(res1->href, res2->href);
                break;
            }
            case DAVQL_RES_CONTENTLENGTH: {
                int c = res1->contentlength == res2->contentlength;
                ret = c ? 0 : (res1->contentlength < res2->contentlength?-1:1);
                break;
            }
            case DAVQL_RES_CONTENTTYPE: {
                ret = strcmp(res1->contenttype, res2->contenttype);
                break;
            }
            case DAVQL_RES_CREATIONDATE: {
                int c = res1->creationdate == res2->creationdate;
                ret = c ? 0 : (res1->creationdate < res2->creationdate?-1:1);
                break;
            }
            case DAVQL_RES_LASTMODIFIED: {
                int c = res1->lastmodified == res2->lastmodified;
                ret = c ? 0 : (res1->lastmodified < res2->lastmodified?-1:1);
                break;
            }
            case DAVQL_RES_ISCOLLECTION: {
                int c = res1->iscollection == res2->iscollection;
                ret = c ? 0 : (res1->iscollection < res2->iscollection?-1:1);
                break;
            }
            default: ret = 0;
        }
    } else if(cr->type == 1) {
        DavXmlNode *xvalue1 = resource_get_property_k(res1, cr->column.property);
        DavXmlNode *xvalue2 = resource_get_property_k(res2, cr->column.property);
        char *value1 = dav_xml_getstring(xvalue1);
        char *value2 = dav_xml_getstring(xvalue2);
        if(!value1) {
            ret = value2 ? -1 : 0;
        } else if(!value2) {
            ret = value1 ? 1 : 0;
        } else {
            ret = strcmp(value1, value2);
        }
    } else {
        return 0;
    }
    
    return cr->descending ? -ret : ret;
}

void resource_add_ordered_child(DavResource *parent, DavResource *child, UcxList *ordercr) {
    if(!ordercr) {
        resource_add_child(parent, child);
        return;
    }
    
    child->parent = parent;
    
    if(!parent->children) {
        child->next = NULL;
        child->prev = NULL;
        parent->children = child;
    } else {
        DavResource *resource = parent->children;
        while(resource) {
            int r = 0;
            UCX_FOREACH(elm, ordercr) {
                DavOrderCriterion *cr = elm->data;
                r = resource_cmp(child, resource, cr);
                if(r != 0) {
                    break;
                }
            }
            
            if(r < 0) {
                // insert child before resource
                child->prev = resource->prev;
                child->next = resource;
                if(resource->prev) {
                    resource->prev->next = child;
                } else {
                    parent->children = child;
                }
                resource->prev = child;
                break;
            } if(!resource->next) {
                // append child
                child->prev = resource;
                child->next = NULL;
                resource->next = child;
                break;
            } else {
                resource = resource->next;
            }
        }
    }
}

char* dav_get_string_property(DavResource *res, char *name) {
    char *pns;
    char *pname;
    dav_get_property_namespace_str(res->session->context, name, &pns, &pname);
    if(!pns || !pname) {
        return NULL;
    }
    return dav_get_string_property_ns(res, pns, pname);
}

char* dav_get_string_property_ns(DavResource *res, char *ns, char *name) {
    DavXmlNode *prop = dav_get_property_ns(res, ns, name);
    if(!prop) {
        return NULL;
    }
    return dav_xml_getstring(prop);
}

DavXmlNode* dav_get_property(DavResource *res, char *name) {
    char *pns;
    char *pname;
    dav_get_property_namespace_str(res->session->context, name, &pns, &pname);
    if(!pns || !pname) {
        return NULL;
    }
    return dav_get_property_ns(res, pns, pname);
}

static DavXmlNode* get_property_ns(DavResource *res, DavBool encrypted, const char *ns, const char *name) {
    if(!ns || !name) {
        return NULL;
    }
    
    DavResourceData *data = res->data;
    
    DavXmlNode *property = NULL;
    UcxList *remove_list = NULL;
    UcxList *set_list = NULL;
    
    if(encrypted) {
        // check if crypto_properties because it will only be created
        // if the resource has encrypted properties
        if(!data->crypto_properties) {
            return NULL;
        }
        property = resource_get_encrypted_property(res, ns, name);
        remove_list = data->crypto_remove;
        set_list = data->crypto_set;
    } else {
        property = resource_get_property(res, ns, name);
        remove_list = data->remove;
        set_list = data->set;
    }
    
    // resource_get_property only returns persistent properties
    // check the remove and set list
    if(property) {
        // if the property is in the remove list, we return NULL
        UCX_FOREACH(elm, remove_list) {
            DavProperty *p = elm->data;
            if(!strcmp(p->name, name) && !strcmp(p->ns->name, ns)) {
                return NULL;
            }
        }
    }
    // the set list contains property updates
    // we return an updated property if possible
    UCX_FOREACH(elm, set_list) {
        DavProperty *p = elm->data;
        if(!strcmp(p->name, name) && !strcmp(p->ns->name, ns)) {
            return p->value; // TODO: fix
        }
    }
    // no property update
    
    return property;
}

DavXmlNode* dav_get_property_ns(DavResource *res, const char *ns, const char *name) {
    DavXmlNode *property_value = get_property_ns(res, FALSE, ns, name);
    
    if(!property_value && DAV_DECRYPT_PROPERTIES(res->session)) {
        property_value = get_property_ns(res, TRUE, ns, name);
    }
    
    return property_value;
}

DavXmlNode* dav_get_encrypted_property_ns(DavResource *res, const char *ns, const char *name) {
    return get_property_ns(res, TRUE, ns, name);
}

static DavProperty* createprop(DavSession *sn, const char *ns, const char *name) {
    DavProperty *property = dav_session_malloc(sn, sizeof(DavProperty));
    property->name = dav_session_strdup(sn, name);
    property->value = NULL;
    
    DavNamespace *namespace = dav_session_malloc(sn, sizeof(DavNamespace));
    namespace->prefix = NULL;
    namespace->name = dav_session_strdup(sn, ns);
    
    property->ns = namespace;
    
    return property;
}

void dav_set_string_property(DavResource *res, char *name, char *value) {
    char *pns;
    char *pname;
    dav_get_property_namespace_str(res->session->context, name, &pns, &pname);
    dav_set_string_property_ns(res, pns, pname, value);
}

void dav_set_string_property_ns(DavResource *res, char *ns, char *name, char *value) {
    DavSession *sn = res->session;
    UcxAllocator *a = res->session->mp->allocator;
    DavResourceData *data = res->data;
    
    DavProperty *property = createprop(res->session, ns, name);
    property->value = dav_text_node(res->session, value);
    
    if(DAV_ENCRYPT_PROPERTIES(sn) && dav_namespace_is_encrypted(sn->context, ns)) {
        data->crypto_set = ucx_list_append_a(a, data->crypto_set, property);
    } else {
        data->set = ucx_list_append_a(a, data->set, property);
    }
}

void dav_set_property(DavResource *res, char *name, DavXmlNode *value) {
    char *pns;
    char *pname;
    dav_get_property_namespace_str(res->session->context, name, &pns, &pname);
    dav_set_property_ns(res, pns, pname, value);
}

void dav_set_property_ns(DavResource *res, char *ns, char *name, DavXmlNode *value) {
    DavSession *sn = res->session;
    UcxAllocator *a = sn->mp->allocator; 
    DavResourceData *data = res->data;
    
    DavProperty *property = createprop(sn, ns, name);
    // TODO: this function should copy the value
    //       but we also need a function, that doesn't create a copy
    property->value = value;
    
    if(DAV_ENCRYPT_PROPERTIES(sn) && dav_namespace_is_encrypted(sn->context, ns)) {
        data->crypto_set = ucx_list_append_a(a, data->crypto_set, property);
    } else {
        data->set = ucx_list_append_a(a, data->set, property);
    }
}

void dav_remove_property(DavResource *res, char *name) {
    char *pns;
    char *pname;
    dav_get_property_namespace_str(res->session->context, name, &pns, &pname);
    dav_remove_property_ns(res, pns, pname);
}

void dav_remove_property_ns(DavResource *res, char *ns, char *name) {
    DavSession *sn = res->session;
    DavResourceData *data = res->data;
    UcxAllocator *a = res->session->mp->allocator;
    
    DavProperty *property = createprop(res->session, ns, name);
    
    if(DAV_ENCRYPT_PROPERTIES(sn) && dav_namespace_is_encrypted(sn->context, ns)) {
        data->crypto_remove = ucx_list_append_a(a, data->crypto_remove, property);
    } else {
        data->remove = ucx_list_append_a(a, data->remove, property);
    }
}

void dav_set_encrypted_property_ns(DavResource *res, char *ns, char *name, DavXmlNode *value) {
    UcxAllocator *a = res->session->mp->allocator;
    DavResourceData *data = res->data;
    
    DavProperty *property = createprop(res->session, ns, name);
    property->value = value; // TODO: copy node?
    
    data->crypto_set = ucx_list_append_a(a, data->crypto_set, property);
}

void dav_set_encrypted_string_property_ns(DavResource *res, char *ns, char *name, char *value) {
    UcxAllocator *a = res->session->mp->allocator;
    DavResourceData *data = res->data;
    
    DavProperty *property = createprop(res->session, ns, name);
    property->value = dav_text_node(res->session, value);
    
    data->crypto_set = ucx_list_append_a(a, data->crypto_set, property);
}

void dav_remove_encrypted_property_ns(DavResource *res, char *ns, char *name) {
    DavResourceData *data = res->data;
    UcxAllocator *a = res->session->mp->allocator;
    
    DavProperty *property = createprop(res->session, ns, name);
    
    data->crypto_remove = ucx_list_append_a(a, data->crypto_remove, property);
}

static int compare_propname(const void *a, const void *b) {
    const DavPropName *p1 = a;
    const DavPropName *p2 = b;
    
    int result = strcmp(p1->ns, p2->ns);
    if(result) {
        return result;
    } else {
        return strcmp(p1->name, p2->name);
    }
}

DavPropName* dav_get_property_names(DavResource *res, size_t *count) {
    DavResourceData *data = res->data;
    
    *count = data->properties->count;
    DavPropName *names = dav_session_calloc(
            res->session,
            *count,
            sizeof(DavPropName));
    
    
    UcxMapIterator i = ucx_map_iterator(data->properties);
    DavProperty *value;
    int j = 0;
    UCX_MAP_FOREACH(key, value, i) {
        DavPropName *name = &names[j];
        
        name->ns = value->ns->name;
        name->name = value->name;
        
        j++;
    }
    
    qsort(names, *count, sizeof(DavPropName), compare_propname);
    
    return names;
}


void dav_set_content(DavResource *res, void *stream, dav_read_func read_func, dav_seek_func seek_func) {
    DavResourceData *data = res->data;
    data->content = stream;
    data->read = read_func;
    data->seek = seek_func;
    data->length = 0;
}

void dav_set_content_data(DavResource *res, char *content, size_t length) {
    DavSession *sn = res->session;
    DavResourceData *data = res->data;
    data->content = dav_session_malloc(sn, length);
    memcpy(data->content, content, length);
    data->read = NULL;
    data->seek = NULL;
    data->length = length;
}

void dav_set_content_length(DavResource *res, size_t length) {
    DavResourceData *data = res->data;
    data->length = length;
}


int dav_load(DavResource *res) {
    UcxBuffer *rqbuf = create_allprop_propfind_request();
    int ret = dav_propfind(res->session, res, rqbuf);
    ucx_buffer_free(rqbuf);
    return ret;
}

int dav_load_prop(DavResource *res, DavPropName *properties, size_t numprop) {
    UcxMempool *mp = ucx_mempool_new(64);
    
    UcxList *proplist = NULL;
    for(size_t i=0;i<numprop;i++) {
        DavProperty *p = ucx_mempool_malloc(mp, sizeof(DavProperty));
        p->name = properties[i].name;
        p->ns = ucx_mempool_malloc(mp, sizeof(DavNamespace));
        p->ns->name = properties[i].ns;
        if(!strcmp(properties[i].ns, "DAV:")) {
            p->ns->prefix = "D";
        } else {
            p->ns->prefix = ucx_asprintf(mp->allocator, "x%d", i).ptr;
        }
        p->value = NULL;
        proplist = ucx_list_append_a(mp->allocator, proplist, p);
    }
    
    UcxBuffer *rqbuf = create_propfind_request(res->session, proplist, "propfind", 0);
    int ret = dav_propfind(res->session, res, rqbuf);
    ucx_buffer_free(rqbuf);
    ucx_mempool_destroy(mp);
    return ret;
}


static void init_hash_stream(HashStream *hstr, void *stream, dav_read_func readfn, dav_seek_func seekfn) {
    hstr->sha = NULL;
    hstr->stream = stream;
    hstr->read = readfn;
    hstr->seek = seekfn;
    hstr->error = 0;
}

static size_t dav_read_h(void *buf, size_t size, size_t nelm, void *stream) {
    HashStream *s = stream;
    if(!s->sha) {
        s->sha = dav_hash_init();
    }
     
    size_t r = s->read(buf, size, nelm, s->stream);
    dav_hash_update(s->sha, buf, r);
    return r;
}

static int dav_seek_h(void *stream, long offset, int whence) {
    HashStream *s = stream;
    if(offset == 0 && whence == SEEK_SET) {
        unsigned char buf[DAV_SHA256_DIGEST_LENGTH];
        dav_hash_final(s->sha, buf);
        s->sha = NULL;
    } else {
        s->error = 1;
    }
    return s->seek(s->stream, offset, whence);
}


int dav_store(DavResource *res) {
    DavSession *sn = res->session;
    DavResourceData *data = res->data;
    
    util_set_url(sn, dav_resource_get_href(res));
    
    DavLock *lock = dav_get_lock(sn, res->path);
    char *locktoken = lock ? lock->token : NULL;
    
    // store content
    if(data->content) {
        int encryption = DAV_ENCRYPT_CONTENT(sn) && sn->key;
        CURLcode ret;
        if(encryption) {
            AESEncrypter *enc = NULL;
            UcxBuffer *buf = NULL;
            if(data->read) {
                enc = aes_encrypter_new(
                        sn->key,
                        data->content,
                        data->read,
                        data->seek);
            } else {
                buf = ucx_buffer_new(data->content, data->length, 0);
                buf->size = data->length;
                enc = aes_encrypter_new(
                        sn->key,
                        buf,
                        (dav_read_func)ucx_buffer_read,
                        (dav_seek_func)dav_buffer_seek);
            }
              
            // put resource
            ret = do_put_request(
                    sn,
                    locktoken,
                    TRUE,
                    enc,
                    (dav_read_func)aes_read,
                    (dav_seek_func)aes_encrypter_reset,
                    0);
            
            // get sha256 hash
            dav_get_hash(&enc->sha256, (unsigned char*)data->hash);
            char *enc_hash = aes_encrypt(data->hash, DAV_SHA256_DIGEST_LENGTH, sn->key);
            
            aes_encrypter_close(enc);
            if(buf) {
                ucx_buffer_free(buf);
            }
            
            // add crypto properties
            // TODO: store the properties later
            if(resource_add_crypto_info(sn, res->href, res->name, enc_hash)) {
                free(enc_hash);
                return 1;
            }
            resource_add_string_property(res, DAV_NS, "crypto-hash", enc_hash);
            free(enc_hash);
        } else if((sn->flags & DAV_SESSION_STORE_HASH) == DAV_SESSION_STORE_HASH) {
            HashStream hstr;
            UcxBuffer *iobuf = NULL;
            if(!data->read) {
                iobuf = ucx_buffer_new(data->content, data->length, 0);
                iobuf->size = data->length;
                init_hash_stream(
                        &hstr,
                        iobuf,
                        (dav_read_func)ucx_buffer_read,
                        (dav_seek_func)ucx_buffer_seek);
            } else {
                init_hash_stream(
                        &hstr,
                        data->content,
                        data->read,
                        data->seek);
            }
            
            ret = do_put_request(
                    sn,
                    locktoken,
                    TRUE,
                    &hstr,
                    dav_read_h,
                    (dav_seek_func)dav_seek_h,
                    data->length);
            
            if(hstr.sha) {
                dav_hash_final(hstr.sha, (unsigned char*)data->hash);
                char *hash = util_hexstr((unsigned char*)data->hash, 32);
                dav_set_string_property_ns(res, DAV_NS, "content-hash", hash);
                free(hash);
            }
        } else {
            ret = do_put_request(
                    sn,
                    locktoken,
                    TRUE,
                    data->content,
                    data->read,
                    data->seek,
                    data->length);
        }
        
        long status = 0;
        curl_easy_getinfo(sn->handle, CURLINFO_RESPONSE_CODE, &status);
        if(ret == CURLE_OK && (status >= 200 && status < 300)) {
            res->session->error = 0;
            // cleanup node data
            if(!data->read) {
                ucx_mempool_free(sn->mp, data->content);
            }
            data->content = NULL;
            data->read = NULL;
            data->length = 0;
        } else {
            dav_session_set_error(sn, ret, status);
            return 1;
        }
    }
    
    // generate crypto-prop content
    if(DAV_ENCRYPT_PROPERTIES(sn) && sn->key && (data->crypto_set || data->crypto_remove)) {
        DavResource *crypto_res = dav_resource_new_href(sn, res->href);
        int ret = 1;
        
        if(crypto_res) {
            UcxBuffer *rqbuf = create_cryptoprop_propfind_request();
            ret = dav_propfind(res->session, res, rqbuf);
            ucx_buffer_free(rqbuf);
        }
        
        if(!ret) {
            DavXmlNode *crypto_prop_node = dav_get_property_ns(crypto_res, DAV_NS, "crypto-prop");
            UcxMap *crypto_props = parse_crypto_prop(sn, sn->key, crypto_prop_node);
            if(!crypto_props) {
                // resource hasn't encrypted properties yet
                crypto_props = ucx_map_new(32); // create new map
            }
            
            // remove all properties
            UCX_FOREACH(elm, data->crypto_remove) {
                if(crypto_props->count == 0) {
                    break; // map already empty, can't remove any more
                }
                
                DavProperty *property = elm->data;
                sstr_t key = dav_property_key(property->ns->name, property->name);
                DavProperty *existing_prop = ucx_map_sstr_remove(crypto_props, key);
                if(existing_prop) {
                    // TODO: free existing_prop
                }                
                free(key.ptr);
            }
            
            // set properties
            UCX_FOREACH(elm, data->crypto_set) {
                DavProperty *property = elm->data;
                sstr_t key = dav_property_key(property->ns->name, property->name);
                DavProperty *existing_prop = ucx_map_sstr_remove(crypto_props, key);
                ucx_map_sstr_put(crypto_props, key, property);
                if(existing_prop) {
                    // TODO: free existing_prop
                }  
                free(key.ptr);
            }
            
            DavXmlNode *crypto_prop_value = create_crypto_prop(sn, crypto_props);
            if(crypto_prop_value) {
                DavProperty *new_crypto_prop = createprop(sn, DAV_NS, "crypto-prop");
                new_crypto_prop->value = crypto_prop_value;
                data->set = ucx_list_prepend_a(sn->mp->allocator, data->set, new_crypto_prop);
            }
            
            dav_resource_free(crypto_res);
        }
        
        if(ret) {
            return 1;
        }
    }
    
    // store properties
    int r = 0;
    sn->error = DAV_OK;
    if(data->set || data->remove) {
        UcxBuffer *request = create_proppatch_request(data);
        UcxBuffer *response = ucx_buffer_new(NULL, 1024, UCX_BUFFER_AUTOEXTEND);
        //printf("request:\n%.*s\n\n", request->pos, request->space);

        CURLcode ret = do_proppatch_request(sn, locktoken, request, response);
        long status = 0;
        curl_easy_getinfo (sn->handle, CURLINFO_RESPONSE_CODE, &status);
        if(ret == CURLE_OK && status == 207) {
            //printf("%s\n", response->space);
            // TODO: parse response
            // TODO: cleanup node data correctly
            data->set = NULL;
            data->remove = NULL;
        } else {
            dav_session_set_error(sn, ret, status);
            r = -1;
        }
        
        ucx_buffer_free(request);
        ucx_buffer_free(response);
    }
     
    return r;
}

#if LIBCURL_VERSION_MAJOR >= 7 && LIBCURL_VERSION_MINOR >= 32
static void set_progressfunc(DavResource *res) {
    CURL *handle = res->session->handle;
    curl_easy_setopt(handle, CURLOPT_XFERINFOFUNCTION, dav_session_get_progress);
    curl_easy_setopt(handle, CURLOPT_XFERINFODATA, res);
    curl_easy_setopt(handle, CURLOPT_NOPROGRESS, 0L);
}

static void unset_progressfunc(DavResource *res) {
    CURL *handle = res->session->handle;
    curl_easy_setopt(handle, CURLOPT_XFERINFOFUNCTION, NULL);
    curl_easy_setopt(handle, CURLOPT_XFERINFODATA, NULL);
    curl_easy_setopt(handle, CURLOPT_NOPROGRESS, 1L);
}
#else
static void set_progressfunc(DavResource *res) {
    
}
static void unset_progressfunc(DavResource *res) {
    
}
#endif

int dav_get_content(DavResource *res, void *stream, dav_write_func write_fnc) { 
    DavSession *sn = res->session;
    CURL *handle = sn->handle;
    util_set_url(res->session, dav_resource_get_href(res));
    
    // check encryption
    AESDecrypter *dec = NULL;
    DavKey *key = NULL;
    if(DAV_DECRYPT_CONTENT(sn)) {
        char *keyname = dav_get_string_property_ns(res, DAV_NS, "crypto-key");
        if(keyname) {
            key = dav_context_get_key(sn->context, keyname);
            if(key) {
                dec = aes_decrypter_new(key, stream, write_fnc);
                stream = dec;
                write_fnc = (dav_write_func)aes_write;
            }
        }
    }
    
    curl_easy_setopt(handle, CURLOPT_HTTPHEADER, NULL);
    curl_easy_setopt(handle, CURLOPT_CUSTOMREQUEST, NULL);
    curl_easy_setopt(handle, CURLOPT_PUT, 0L);
    curl_easy_setopt(handle, CURLOPT_UPLOAD, 0L);
    
    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, write_fnc);
    curl_easy_setopt(handle, CURLOPT_WRITEDATA, stream);
    
    if(sn->get_progress) {
        set_progressfunc(res);
    }
    
    long status = 0;
    CURLcode ret = dav_session_curl_perform(sn, &status);
    
    if(sn->get_progress) {
        unset_progressfunc(res);
    }
    
    char *hash = NULL;
    if(dec) {
        aes_decrypter_shutdown(dec); // get final bytes
        
        // get hash
        unsigned char sha[DAV_SHA256_DIGEST_LENGTH];
        dav_get_hash(&dec->sha256, sha);
        hash = util_hexstr(sha, DAV_SHA256_DIGEST_LENGTH);
        
        aes_decrypter_close(dec);
    }
    
    if(ret == CURLE_OK && (status >= 200 && status < 300)) {
        int verify_failed = 0;
        if(DAV_DECRYPT_CONTENT(sn) && key) {
            // try to verify the content
            char *res_hash = dav_get_string_property_ns(res, DAV_NS, "crypto-hash");

            if(res_hash) {
                size_t len = 0;
                char *dec_hash = aes_decrypt(res_hash, &len, key);
                char *hex_hash = util_hexstr((unsigned char*)dec_hash, len);
                if(strcmp(hash, hex_hash)) {
                    verify_failed = 1;
                }
                free(dec_hash);
                free(hex_hash);
            }
        }
        if(hash) {
            free(hash);
        }
        
        if(verify_failed) {
            res->session->error = DAV_CONTENT_VERIFICATION_ERROR;
            return 1;
        }
        
        res->session->error = DAV_OK;
        return 0;
    } else {
        if(hash) {
            free(hash);
        }
        dav_session_set_error(res->session, ret, status);
        return 1;
    }
}

DavResource* dav_create_child(DavResource *parent, char *name) {
    DavResource *res = dav_resource_new_child(parent->session, parent, name);
    if(dav_create(res)) {
        dav_resource_free(res);
        return NULL;
    } else {
        return res;
    }
}

int dav_delete(DavResource *res) {
    CURL *handle = res->session->handle;
    util_set_url(res->session, dav_resource_get_href(res));
    
    DavLock *lock = dav_get_lock(res->session, res->path);
    char *locktoken = lock ? lock->token : NULL;
    
    UcxBuffer *response = ucx_buffer_new(NULL, 4096, UCX_BUFFER_AUTOEXTEND);
    CURLcode ret = do_delete_request(res->session, locktoken, response);
    long status = 0;
    curl_easy_getinfo (handle, CURLINFO_RESPONSE_CODE, &status);
    int r = 0;
    if(ret == CURLE_OK && (status >= 200 && status < 300)) {
        res->session->error = DAV_OK;
        res->exists = 0;
        
        // TODO: parse response
        // TODO: free res
    } else {
        dav_session_set_error(res->session, ret, status);
        r = 1;
    }
    
    ucx_buffer_free(response);
    return r;
}

static int create_ancestors(DavSession *sn, char *href, char *path) {
    CURL *handle = sn->handle;
    CURLcode code;
    
    DavLock *lock = dav_get_lock(sn, path);
    char *locktoken = lock ? lock->token : NULL;
    
    long status = 0;
    int ret = 0;
    
    if(strlen(path) <= 1) {
        return 0;
    }
    
    char *p = util_parent_path(path);
    char *h = util_parent_path(href);
    
    for(int i=0;i<2;i++) {
        util_set_url(sn, h);
        code = do_mkcol_request(sn, locktoken);
        curl_easy_getinfo(handle, CURLINFO_RESPONSE_CODE, &status);
        if(status == 201) {
            // resource successfully created
            char *name = util_resource_name(p);
            int len = strlen(name);
            if(name[len - 1] == '/') {
                name[len - 1] = '\0';
            }
            if(resource_add_crypto_info(sn, h, name, NULL)) {
                sn->error = DAV_ERROR;
                dav_session_set_errstr(sn, "Cannot set crypto properties for ancestor");
            }
            break;
        } else if(status == 405) {
            // parent already exists
            break;
        } else if(status == 409) {
            // parent doesn't exist
            if(create_ancestors(sn, h, p)) {
                ret = 1;
                break;
            }
        } else {
            dav_session_set_error(sn, code, status);
            ret = 1;
            break;
        }
    }
    
    free(p);
    free(h);
    return ret;
}

static int create_resource(DavResource *res, int *status) {
    DavSession *sn = res->session;
    CURL *handle = sn->handle;
    util_set_url(sn, dav_resource_get_href(res));
    
    DavLock *lock = dav_get_lock(res->session, res->path);
    char *locktoken = lock ? lock->token : NULL;
    
    CURLcode code;
    if(res->iscollection) {
        code = do_mkcol_request(sn, locktoken);
    } else {
        code = do_put_request(sn, locktoken, TRUE, "", NULL, NULL, 0); 
    }
    long s = 0;
    curl_easy_getinfo(handle, CURLINFO_RESPONSE_CODE, &s);
    *status = s;
    if(code == CURLE_OK && (s >= 200 && s < 300)) {
        sn->error = DAV_OK;
        // if the session has encrypted file names, add crypto infos
        if(!resource_add_crypto_info(sn, res->href, res->name, NULL)) {
            // do a minimal propfind request
            UcxBuffer *rqbuf = create_propfind_request(sn, NULL, "propfind", 0);
            int ret = dav_propfind(sn, res, rqbuf);
            ucx_buffer_free(rqbuf);
            return ret;
        } else {
            return 1;
        }
    } else {
        dav_session_set_error(sn, code, s);
        return 1;
    }
}

int dav_create(DavResource *res) {
    int status;
    if(!create_resource(res, &status)) {
        // resource successfully created
        res->exists = 1;
        return 0;
    }
    
    if(status == 403 || status == 409 || status == 404) {
        // create intermediate collections
        if(create_ancestors(res->session, res->href, res->path)) {
            return 1;
        }
    }
    
    return create_resource(res, &status);
}

int dav_exists(DavResource *res) {
    if(!dav_load_prop(res, NULL, 0)) {
        res->exists = 1;
        return 1;
    } else {
        if(res->session->error == DAV_NOT_FOUND) {
            res->exists = 0;
        }
        return 0;
    }
}

static int dav_cp_mv_url(DavResource *res, char *desturl, _Bool copy, _Bool override) {
    DavSession *sn = res->session;
    CURL *handle = sn->handle;
    util_set_url(sn, dav_resource_get_href(res));
    
    DavLock *lock = dav_get_lock(sn, res->path);
    char *locktoken = lock ? lock->token : NULL;
    
    CURLcode ret = do_copy_move_request(sn, desturl, locktoken, copy, override);
    
    long status = 0;
    curl_easy_getinfo (handle, CURLINFO_RESPONSE_CODE, &status);
    if(ret == CURLE_OK && (status >= 200 && status < 300)) {
        return 0;
    } else {
        dav_session_set_error(sn, ret, status);
        return 1;
    }
}

static int dav_cp_mv(DavResource *res, char *newpath, _Bool copy, _Bool override) {
    char *dest = dav_session_get_href(res->session, newpath);
    char *desturl = util_get_url(res->session, dest);
    dav_session_free(res->session, dest);
    
    int ret = dav_cp_mv_url(res, desturl, copy, override);
    free(desturl);
    return ret;
}

int dav_copy(DavResource *res, char *newpath) {
    return dav_cp_mv(res, newpath, true, false);
}

int dav_move(DavResource *res, char *newpath) {
    return dav_cp_mv(res, newpath, false, false);
}

int dav_copy_o(DavResource *res, char *newpath, DavBool override) {
    return dav_cp_mv(res, newpath, true, override);
}

int dav_move_o(DavResource *res, char *newpath, DavBool override) {
    return dav_cp_mv(res, newpath, false, override);
}

int dav_copyto(DavResource *res, char *url, DavBool override) {
    return dav_cp_mv_url(res, url, true, override);
}

int dav_moveto(DavResource *res, char *url, DavBool override) {
    return dav_cp_mv_url(res, url, false, override);
}

int dav_lock(DavResource *res) {
    return dav_lock_t(res, 0);
}

int dav_lock_t(DavResource *res, time_t timeout) {
    DavSession *sn = res->session;
    CURL *handle = sn->handle;
    util_set_url(sn, dav_resource_get_href(res));
    
    UcxBuffer *request = create_lock_request();
    UcxBuffer *response = ucx_buffer_new(NULL, 512, UCX_BUFFER_AUTOEXTEND);
    CURLcode ret = do_lock_request(sn, request, response, timeout);
    
    //printf("\nlock\n");
    //printf("%.*s\n\n", request->size, request->space);
    //printf("%.*s\n\n", response->size, response->space);
    
    ucx_buffer_free(request);
    
    long status = 0;
    curl_easy_getinfo (handle, CURLINFO_RESPONSE_CODE, &status);
    if(ret == CURLE_OK && (status >= 200 && status < 300)) {
        LockDiscovery lock;
        if(parse_lock_response(sn, response, &lock)) {
            sn->error = DAV_ERROR;
            ucx_buffer_free(response);
            return -1;
        }
        ucx_buffer_free(response);
        
        DavLock *l = dav_create_lock(sn, lock.locktoken, lock.timeout);
        free(lock.locktoken);
        free(lock.timeout);
        
        int r = 0;
        if(res->iscollection) {
            r = dav_add_collection_lock(sn, res->path, l);
        } else {
            r = dav_add_resource_lock(sn, res->path, l);
        }
        
        if(r == 0) {
            return 0;
        } else {
            (void)dav_unlock(res);
            sn->error = DAV_ERROR;
            dav_destroy_lock(sn, l);
            return -1;
        }
    } else {
        dav_session_set_error(sn, ret, status);
        ucx_buffer_free(response);
        return -1;
    }
}

int dav_unlock(DavResource *res) {
    DavSession *sn = res->session;
    CURL *handle = sn->handle;
    util_set_url(sn, dav_resource_get_href(res));
    
    DavLock *lock = dav_get_lock(res->session, res->path);
    if(!lock) {
        sn->error = DAV_ERROR;
        return -1;
    }
    
    CURLcode ret = do_unlock_request(sn, lock->token);
    long status = 0;
    curl_easy_getinfo (handle, CURLINFO_RESPONSE_CODE, &status);
    if(ret == CURLE_OK && (status >= 200 && status < 300)) {
        dav_remove_lock(sn, res->path, lock);
    } else {
        dav_session_set_error(sn, ret, status);
        return 1;
    }
    
    return 0;
}


int resource_add_crypto_info(DavSession *sn, const char *href, const char *name, const char *hash) {
    if(!DAV_IS_ENCRYPTED(sn)) {
        return 0;
    }
    
    UcxBuffer *request = create_crypto_proppatch_request(sn, sn->key, name, hash);
    UcxBuffer *response = ucx_buffer_new(NULL, 1024, UCX_BUFFER_AUTOEXTEND);
    
    util_set_url(sn, href);
    // TODO: lock
    CURLcode ret = do_proppatch_request(sn, NULL, request, response);
    ucx_buffer_free(request);
    long status = 0;
    curl_easy_getinfo (sn->handle, CURLINFO_RESPONSE_CODE, &status);
    if(ret == CURLE_OK && status == 207) {
        // TODO: parse response
        sn->error = DAV_OK;   
        ucx_buffer_free(response);
        return 0;
    } else {
        dav_session_set_error(sn, ret, status);
        ucx_buffer_free(response);
        return 1;
    }
}

/* ----------------------------- crypto-prop  ----------------------------- */

DavXmlNode* create_crypto_prop(DavSession *sn, UcxMap *properties) {
    if(!sn->key) {
        return NULL;
    }
    
    UcxBuffer *content = ucx_buffer_new(NULL, 2048, UCX_BUFFER_AUTOEXTEND);
    
    // create an xml document containing all properties
    UcxMap *nsmap = ucx_map_new(8);
    ucx_map_cstr_put(nsmap, "DAV:", strdup("D"));
    
    ucx_buffer_puts(content, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
    ucx_buffer_puts(content, "<D:prop xmlns:D=\"DAV:\">\n");
    
    UcxMapIterator i = ucx_map_iterator(properties);
    DavProperty *prop;
    UCX_MAP_FOREACH(key, prop, i) {
        DavXmlNode pnode;
        pnode.type = DAV_XML_ELEMENT;
        pnode.namespace = prop->ns->name;
        pnode.name = prop->name;
        pnode.prev = NULL;
        pnode.next = NULL;
        pnode.children = prop->value;
        pnode.parent = NULL;
        pnode.attributes = NULL;
        pnode.content = NULL;
        pnode.contentlength = 0;
        
        dav_print_node(content, (write_func)ucx_buffer_write, nsmap, &pnode);
        ucx_buffer_putc(content, '\n');
    }
    
    ucx_buffer_puts(content, "</D:prop>");
    
    ucx_map_free_content(nsmap, (ucx_destructor)free);
    ucx_map_free(nsmap);
    
    // encrypt xml document
    char *crypto_prop_content = aes_encrypt(content->space, content->size, sn->key);
    ucx_buffer_free(content);
    
    DavXmlNode *ret = NULL;
    if(crypto_prop_content) {
        ret = dav_text_node(sn, crypto_prop_content);
        free(crypto_prop_content);
    }    
    return ret;
}

UcxMap* parse_crypto_prop(DavSession *sn, DavKey *key, DavXmlNode *node) {
    if(!node || node->type != DAV_XML_TEXT || node->contentlength == 0) {
        return NULL;
    }
    
    return parse_crypto_prop_str(sn, key, node->content);
}

UcxMap* parse_crypto_prop_str(DavSession *sn, DavKey *key, const char *content) {
    size_t len = 0;
    char *dec_str = aes_decrypt(content, &len, key);
    
    xmlDoc *doc = xmlReadMemory(dec_str, len, NULL, NULL, 0);
    free(dec_str);
    if(!doc) {
        return NULL;
    }
    
    int err = 0;
    xmlNode *xml_root = xmlDocGetRootElement(doc);
    if(xml_root) {
        if(
                !xml_root->ns ||
                !xstreq(xml_root->name, "prop") ||
                !xstreq(xml_root->ns->href, "DAV:"))
        {
            err = 1;
        }
    } else {
        err = 1;
    }
    
    if(err) {
        xmlFreeDoc(doc);
        return NULL;
    }
    
    // ready to get the properties
    UcxMap *map = ucx_map_new(32);
    xmlNode *n = xml_root->children;
    while(n) {
        if(n->type == XML_ELEMENT_NODE && n->ns && n->ns->href) {
            DavProperty *property = dav_session_malloc(sn, sizeof(DavProperty));
            property->name = dav_session_strdup(sn, (const char*)n->name);
            property->ns = dav_session_malloc(sn, sizeof(DavNamespace));
            property->ns->name = dav_session_strdup(sn, (const char*)n->ns->href);
            property->ns->prefix = n->ns->prefix ?
                    dav_session_strdup(sn, (const char*)n->ns->prefix) : NULL;
            property->value = n->children ? dav_convert_xml(sn, n->children) : NULL;
            
            sstr_t key = dav_property_key(property->ns->name, property->name);
            ucx_map_sstr_put(map, key, property);
            free(key.ptr);
        }
        n = n->next;
    }
    
    xmlFreeDoc(doc);
    if(map->count == 0) {
        ucx_map_free(map);
        return NULL;
    }
    return map;
}


/* ----------------------------- streams  ----------------------------- */

static size_t in_write(const char *ptr, size_t size, size_t nitems, void *in_stream) {
    DavInputStream *in = in_stream;
    size_t len = size * nitems;
    
    if(in->alloc < len) {
        char *newb = realloc(in->buffer, len);
        if(!newb) {
            if(in->buffer) free(in->buffer);
            in->eof = 1;
            return 0;
        }
        
        in->buffer = newb;
        in->alloc = len;
    }
    
    memcpy(in->buffer, ptr, len);
    
    in->size = len;
    in->pos = 0;
    
    return nitems;
}

DavInputStream* dav_inputstream_open(DavResource *res) {
    DavSession *sn = res->session;
    
    DavInputStream *in = dav_session_malloc(sn, sizeof(DavInputStream));
    if(!in) {
        return NULL;
    }
    memset(in, 0, sizeof(DavInputStream));
    
    in->res = res;
    
    in->c = curl_easy_duphandle(sn->handle); 
    char *url = util_get_url(sn, dav_resource_get_href(res));
    curl_easy_setopt(in->c, CURLOPT_URL, url);
    free(url);
    
    in->m = curl_multi_init();
    
    curl_easy_setopt(in->c, CURLOPT_HTTPHEADER, NULL);
    curl_easy_setopt(in->c, CURLOPT_CUSTOMREQUEST, NULL);
    curl_easy_setopt(in->c, CURLOPT_PUT, 0L);
    curl_easy_setopt(in->c, CURLOPT_UPLOAD, 0L);
    
    curl_multi_add_handle(in->m, in->c);
    
    dav_write_func write_fnc = (dav_write_func)in_write;
    void *stream = in;
    
    // check encryption 
    AESDecrypter *dec = NULL;
    DavKey *key = NULL;
    if(DAV_DECRYPT_CONTENT(sn)) {
        char *keyname = dav_get_string_property_ns(res, DAV_NS, "crypto-key");
        if(keyname) {
            key = dav_context_get_key(sn->context, keyname);
            if(key) {
                dec = aes_decrypter_new(key, stream, write_fnc);
                stream = dec;
                write_fnc = (dav_write_func)aes_write;
            }
        }
    }
    
    curl_easy_setopt(in->c, CURLOPT_WRITEFUNCTION, write_fnc);
    curl_easy_setopt(in->c, CURLOPT_WRITEDATA, stream);
    
    in->dec = dec;
    
    return in;
}

size_t dav_read(void *buf, size_t size, size_t nitems, DavInputStream *in) {
    size_t len = in->size - in->pos;
    size_t rl = size * nitems;
    if(len > 0) {
        len = rl > len ? len : rl;
        len -= len % size;
        memcpy(buf, in->buffer + in->pos, len);
        in->pos += len;
        return len / size;
    }
    in->size = 0;
    
    if(in->eof) {
        if(in->dec) {
            aes_decrypter_shutdown(in->dec); // get final bytes
            aes_decrypter_close(in->dec);
            in->dec = NULL;
        } else {
            return 0;
        }
    } else {
        int running;
        while(!in->eof && in->size == 0) {
            CURLMcode r = curl_multi_perform(in->m, &running);
            if(r != CURLM_OK || running == 0) {
                in->eof = 1;
                break;
            }

            int numfds;
            if(curl_multi_poll(in->m, NULL, 0, 5000, &numfds) != CURLM_OK) {
                in->eof = 1;
            }
        }
    }
    
    return in->size > 0 ? dav_read(buf, size, nitems, in) : 0;
}

void dav_inputstream_close(DavInputStream *in) {
    curl_multi_cleanup(in->m);
    curl_easy_cleanup(in->c);
    if(in->buffer) free(in->buffer);
    dav_session_free(in->res->session, in);
}


static size_t out_read(char *ptr, size_t size, size_t nitems, void *out_stream) {
    DavOutputStream *out = out_stream;
    size_t len = size * nitems;
    size_t available = out->size - out->pos;
    if(available == 0) {
        return 0;
    }
    
    size_t r = len > available ? available : len;
    r -= r % size;
    memcpy(ptr, out->buffer + out->pos, r);
    
    out->pos += r;

    return r / size;
}

static size_t dummy_write(void *buf, size_t s, size_t n, void *data) {
    return s*n;
}

DavOutputStream* dav_outputstream_open(DavResource *res) {
    DavSession *sn = res->session;
    
    DavOutputStream *out = dav_session_malloc(sn, sizeof(DavOutputStream));
    if(!out) {
        return NULL;
    }
    memset(out, 0, sizeof(DavOutputStream));
    
    out->res = res;
    
    out->c = curl_easy_duphandle(sn->handle); 
    char *url = util_get_url(sn, dav_resource_get_href(res));
    curl_easy_setopt(out->c, CURLOPT_URL, url);
    free(url);
    
    out->m = curl_multi_init();
    curl_multi_add_handle(out->m, out->c);
    
    void *stream = out;
    dav_read_func read_fnc = (dav_read_func)out_read;
    
    // if encryption or hashing in enabled, we need a stream wrapper
    if(DAV_ENCRYPT_CONTENT(sn) && sn->key) {
        AESEncrypter *enc = aes_encrypter_new(sn->key, out, (dav_read_func)out_read, NULL);
        out->enc = enc;
        stream = enc;
        read_fnc = (dav_read_func)aes_read;
    } else if((sn->flags & DAV_SESSION_STORE_HASH) == DAV_SESSION_STORE_HASH) {
        HashStream *hstr = dav_session_malloc(sn, sizeof(HashStream));
        out->hstr = hstr;
        init_hash_stream(hstr, out, (dav_read_func)out_read, NULL);
        stream = hstr;
        read_fnc = (dav_read_func)dav_read_h;
    }
    
    curl_easy_setopt(out->c, CURLOPT_HEADERFUNCTION, NULL);
    curl_easy_setopt(out->c, CURLOPT_HTTPHEADER, NULL);
    curl_easy_setopt(out->c, CURLOPT_CUSTOMREQUEST, NULL);
    curl_easy_setopt(out->c, CURLOPT_PUT, 1L);
    curl_easy_setopt(out->c, CURLOPT_UPLOAD, 1L);
    curl_easy_setopt(out->c, CURLOPT_READFUNCTION, read_fnc);
    curl_easy_setopt(out->c, CURLOPT_READDATA, stream);
    curl_easy_setopt(out->c, CURLOPT_SEEKFUNCTION, NULL);
    curl_easy_setopt(out->c, CURLOPT_INFILESIZE, -1);
    curl_easy_setopt(out->c, CURLOPT_INFILESIZE_LARGE, -1L);
    
    curl_easy_setopt(out->c, CURLOPT_WRITEFUNCTION, dummy_write);
    curl_easy_setopt(out->c, CURLOPT_WRITEDATA, NULL);
    
    return out;
}

size_t dav_write(const void *buf, size_t size, size_t nitems, DavOutputStream *out) {
    if(out->eof) return 0;
    
    out->buffer = buf;
    out->size = size * nitems;
    out->pos = 0;
    
    int running;
    while(!out->eof && (out->size == 0 || out->size - out->pos > 0)) {
        CURLMcode r = curl_multi_perform(out->m, &running);
        if(r != CURLM_OK || running == 0) {
            out->eof = 1;
            break;
        }
        
        int numfds;
        if(curl_multi_poll(out->m, NULL, 0, 5000, &numfds) != CURLM_OK) {
            out->eof = 1;
        }
    }
    
    return (out->size - out->pos) / size;
}

int dav_outputstream_close(DavOutputStream *out) {
    DavSession *sn = out->res->session;
    DavResource *res = out->res;
    DavResourceData *data = res->data;
    
    int ret = 0;
    
    dav_write(NULL, 1, 0, out);
    
    curl_multi_cleanup(out->m);
    curl_easy_cleanup(out->c);
    
    int store = 0;
    if(out->enc) {
        // get sha256 hash
        char hash[32];
        dav_get_hash(&out->enc->sha256, (unsigned char*)data->hash);
        aes_encrypter_close(out->enc);
        char *enc_hash = aes_encrypt(hash, DAV_SHA256_DIGEST_LENGTH, sn->key);
        // add crypto properties
        if(resource_add_crypto_info(sn, out->res->href, out->res->name, enc_hash)) {
            ret = 1;
        }
        free(enc_hash);
    } else if(out->hstr) {
        dav_hash_final(out->hstr->sha, (unsigned char*)data->hash);
        char *hash = util_hexstr((unsigned char*)data->hash, 32);
        dav_set_string_property_ns(res, DAV_NS, "content-hash", hash);
        free(hash);
        dav_session_free(sn, out->hstr);
        store = 1;
    }
    
    if(store) {
        ret = dav_store(out->res);
    }
    
    dav_session_free(out->res->session, out);
    
    return ret;
}