libidav/methods.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2015 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 "utils.h"
#include "methods.h"
#include "crypto.h"
#include "session.h"

#include <ucx/utils.h>

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

/* ----------------------------- PROPFIND ----------------------------- */

CURLcode do_propfind_request(
        CURL *handle,
        UcxBuffer *request,
        UcxBuffer *response)
{
    curl_easy_setopt(handle, CURLOPT_CUSTOMREQUEST, "PROPFIND");
    
    // implement own redirection follower
    long follow = 0;
    curl_easy_getinfo(handle, CURLOPT_FOLLOWLOCATION, &follow);
    curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 0L);
    const int maxredirect = 16;
    
    // always try to get information about possible children
    int depth = 1;
    
    struct curl_slist *headers = NULL;
    CURLcode ret = 0;
    
    curl_easy_setopt(handle, CURLOPT_UPLOAD, 1); 
    curl_easy_setopt(handle, CURLOPT_READFUNCTION, ucx_buffer_read);
    curl_easy_setopt(handle, CURLOPT_READDATA, request); 
    curl_easy_setopt(handle, CURLOPT_INFILESIZE, request->size);
    
    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, ucx_buffer_write);
    curl_easy_setopt(handle, CURLOPT_WRITEDATA, response);
    UcxMap *respheaders = ucx_map_new(32);
    util_capture_header(handle, respheaders);
    
    for(int i=0;i<=maxredirect;i++) {
        char *url = NULL;
        curl_easy_getinfo(handle, CURLINFO_EFFECTIVE_URL, &url);
        if(url) {
            size_t ulen = strlen(url);
            if(ulen > 0) {
                if (depth == 1) {
                    headers = curl_slist_append(headers, "Depth: 1");
                } else {
                    headers = curl_slist_append(headers, "Depth: 0");
                }
            } else {
                return CURLE_URL_MALFORMAT;
            }
        } else {
            return CURLE_URL_MALFORMAT;
        }
        headers = curl_slist_append(headers, "Content-Type: text/xml");
        curl_easy_setopt(handle, CURLOPT_HTTPHEADER, headers);

        // reset buffers and perform request
        request->pos = 0;
        response->size = response->pos = 0;
        ret = curl_easy_perform(handle);
        curl_slist_free_all(headers);
        headers = NULL;
        
        /*
         * Handle three cases:
         * 1. We get a Location header (it's a redirect)
         *    => follow the URL we get from the server
         * 2. We communicate with IIS and get a X-MSDAVEXT_Error: 589831
         *    => try with depth 0 next time, it's not a collection
         * 3. Other cases
         *    => the server handled our request and we can stop requesting
         */
        char *location = NULL;
        char *msdavexterror;
        curl_easy_getinfo(handle, CURLINFO_REDIRECT_URL, &location);
        msdavexterror = ucx_map_cstr_get(respheaders, "x-msdavext_error");
        int iishack =  depth == 1 &&
            msdavexterror && !strncmp(msdavexterror, "589831;", 7);
        
        if(location) {
            // redirect
            curl_easy_setopt(handle, CURLOPT_URL, location);
        } else if(iishack) {
            depth = 0;
        } else {
            break;
        }
    }
    
    ucx_map_free_content(respheaders, free);
    ucx_map_free(respheaders);
    
    // reset followlocation option
    curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, follow);
    
    return ret;
}

UcxBuffer* create_allprop_propfind_request() {
    UcxBuffer *buf = ucx_buffer_new(NULL, 512, UCX_BUFFER_AUTOFREE);
    sstr_t s;
    
    s = S("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    s = S("<D:propfind xmlns:D=\"DAV:\">\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    s = S("<D:allprop/></D:propfind>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    return buf;
}

UcxBuffer* create_propfind_request(DavSession *sn, UcxList *properties) {
    UcxBuffer *buf = ucx_buffer_new(NULL, 512, UCX_BUFFER_AUTOEXTEND);
    sstr_t s;
    
    int add_crypto_name = 1;
    int add_crypto_key = 1;
    int add_crypto_hash = 1;
    char *crypto_ns = "idav";
    UcxMap *namespaces = ucx_map_new(8);
    UCX_FOREACH(elm, properties) {
        DavProperty *p = elm->data;
        if(strcmp(p->ns->name, "DAV:")) {
            ucx_map_cstr_put(namespaces, p->ns->prefix, p->ns);
        }
        
        // if the properties list contains the idav properties crypto-name
        // and crypto-key, mark them as existent 
        if(!strcmp(p->ns->name, DAV_NS)) {
            if(!strcmp(p->name, "crypto-name")) {
                add_crypto_name = 0;
                crypto_ns = p->ns->prefix;
            } else if(!strcmp(p->name, "crypto-key")) {
                add_crypto_key = 0;
                crypto_ns = p->ns->prefix;
            } else if(!strcmp(p->name, "crypto-hash")) {
                add_crypto_hash = 0;
                crypto_ns = p->ns->prefix;
            }
        }
    }
    
    DavNamespace idav_ns;
    if(add_crypto_name && add_crypto_key && DAV_CRYPTO(sn)) {
        idav_ns.prefix = "idav";
        idav_ns.name = DAV_NS;
        ucx_map_cstr_put(namespaces, "idav", &idav_ns);
    }
    
    s = S("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    // write root element and namespaces
    s = S("<D:propfind xmlns:D=\"DAV:\"");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    UcxMapIterator mapi = ucx_map_iterator(namespaces);
    UcxKey key;
    DavNamespace *ns;
    UCX_MAP_FOREACH(key, ns, mapi) {
        s = S(" xmlns:");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = sstr(ns->prefix);
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = S("=\"");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = sstr(ns->name);
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = S("\"");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
    }
    s = S(">\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    // default properties
    s = S("<D:prop>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    s = S("<D:creationdate />\n<D:getlastmodified />\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    s = S("<D:getcontentlength />\n<D:getcontenttype />\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    s = S("<D:resourcetype />\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    // crypto properties
    if(DAV_CRYPTO(sn)) {
        if(add_crypto_name) {
            ucx_buffer_putc(buf, '<');
            ucx_buffer_puts(buf, crypto_ns);
            s = S(":crypto-name />\n");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
        }
        if(add_crypto_key) {
            ucx_buffer_putc(buf, '<');
            ucx_buffer_puts(buf, crypto_ns);
            s = S(":crypto-key />\n");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
        }
        if(add_crypto_hash) {
            ucx_buffer_putc(buf, '<');
            ucx_buffer_puts(buf, crypto_ns);
            s = S(":crypto-hash />\n");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
        }
    }
    
    // extra properties
    UCX_FOREACH(elm, properties) {
        DavProperty *prop = elm->data;
        s = S("<");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = sstr(prop->ns->prefix);
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = S(":");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = sstr(prop->name);
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = S(" />\n");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
    }
    
    // end
    s = S("</D:prop>\n</D:propfind>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    ucx_map_free(namespaces);
    return buf;
}

UcxBuffer* create_basic_propfind_request() {
    UcxBuffer *buf = ucx_buffer_new(NULL, 512, UCX_BUFFER_AUTOEXTEND);
    sstr_t s;
    
    s = S("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    s = S("<D:propfind xmlns:D=\"DAV:\" xmlns:i=\"");
    ucx_buffer_write(s.ptr, 1, s.length, buf);  
    s = S(DAV_NS);
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    s = S("\" >\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    // properties
    s = S("<D:prop>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    s = S("<D:resourcetype />\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    s = S("<i:crypto-key />\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    s = S("<i:crypto-name />\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    s = S("<i:crypto-hash />\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    s = S("</D:prop>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    // end
    s = S("</D:propfind>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    return buf;
}

PropfindParser* create_propfind_parser(UcxBuffer *response, char *url) {
    PropfindParser *parser = malloc(sizeof(PropfindParser));
    if(!parser) {
        return NULL;
    }
    parser->document = xmlReadMemory(response->space, response->pos, url, NULL, 0);
    parser->current = NULL;
    if(parser->document) {
        xmlNode *xml_root = xmlDocGetRootElement(parser->document);
        if(xml_root) {
            xmlNode *node = xml_root->children;
            while(node) {
                // find first response tag
                if(node->type == XML_ELEMENT_NODE) {
                    if(xstreq(node->name, "response")) {
                        parser->current = node;
                        break;
                    }
                }
                node = node->next;
            }
            return parser;
        } else {
            xmlFreeDoc(parser->document);
        }
    }
    free(parser);
    return NULL;
}

void destroy_propfind_parser(PropfindParser *parser) {
    if(parser->document) {
        xmlFreeDoc(parser->document);
    }
    free(parser);
}

int get_propfind_response(PropfindParser *parser, ResponseTag *result) {
    if(parser->current == NULL) {
        return 0;
    }
    
    char *href = NULL;
    int iscollection = 0;
    UcxList *properties = NULL; // xmlNode list
    char *crypto_name = NULL; // name set by crypto-name property
    char *crypto_key = NULL;
    
    result->properties = NULL;
    
    xmlNode *node = parser->current->children;
    while(node) {
        if(node->type == XML_ELEMENT_NODE) {
            if(xstreq(node->name, "href")) {
                xmlNode *href_node = node->children;
                if(href_node->type != XML_TEXT_NODE) {
                    // error
                    return -1;
                }
                href = (char*)href_node->content;
            } else if(xstreq(node->name, "propstat")) {
                xmlNode *n = node->children;
                xmlNode *prop_node = NULL;
                int ok = 0;
                // get the status code
                while(n) {
                    if(n->type == XML_ELEMENT_NODE) {
                        if(xstreq(n->name, "prop")) {
                            prop_node = n;
                        } else if(xstreq(n->name, "status")) {
                            xmlNode *status_node = n->children;
                            if(status_node->type != XML_TEXT_NODE) {
                                // error
                                return -1;
                            }
                            sstr_t status_str = sstr((char*)status_node->content);
                            if(status_str.length < 13) {
                                // error
                                return -1;
                            }
                            status_str = sstrsubsl(status_str, 9, 3);
                            if(!sstrcmp(status_str, S("200"))) {
                                ok = 1;
                            }
                        }
                    }    
                    n = n->next;
                }
                // if status is ok, get all properties
                if(ok) {
                    n = prop_node->children;
                    while(n) {
                        if(n->type == XML_ELEMENT_NODE) {
                            properties = ucx_list_append(properties, n);
                            if(xstreq(n->name, "resourcetype")) {
                                xmlNode *rsnode = n->children;
                                if(rsnode && rsnode->type == XML_ELEMENT_NODE) {
                                    // TODO: check content
                                    iscollection = 1;
                                }
                            } else if(xstreq(n->ns->href, DAV_NS)) {
                                if(xstreq(n->name, "crypto-name")) {
                                    crypto_name = util_xml_get_text(n);
                                } else if(xstreq(n->name, "crypto-key")) {
                                    crypto_key = util_xml_get_text(n);
                                }
                            }
                        }
                        n = n->next;
                    }
                }
            }
        }
        node = node->next;
    }
    
    result->href = util_url_path(href);
    result->iscollection = iscollection;
    result->properties = properties;
    result->crypto_name = crypto_name;
    result->crypto_key = crypto_key;
    
    // find next response tag
    xmlNode *next = parser->current->next;
    while(next) {
        if(next->type == XML_ELEMENT_NODE) {
            if(xstreq(next->name, "response")) {
                break;
            }
        }
        next = next->next;
    }
    parser->current = next;
    
    return 1;
}

void cleanup_response(ResponseTag *result) {
    if(result) {
        ucx_list_free(result->properties);
    }
}

int hrefeq(DavSession *sn, char *href1, char *href2) {
    sstr_t href_s = sstr(util_url_decode(sn, href1));
    sstr_t href_r = sstr(util_url_decode(sn, href2));
    int ret = 0;
    if(!sstrcmp(href_s, href_r)) {
        ret = 1;
    } else if(href_s.length == href_r.length + 1) {
        if(href_s.ptr[href_s.length-1] == '/') {
            href_s.length--;
            if(!sstrcmp(href_s, href_r)) {
                ret = 1;
            }
        }
    } else if(href_r.length == href_s.length + 1) {
        if(href_r.ptr[href_r.length-1] == '/') {
            href_r.length--;
            if(!sstrcmp(href_s, href_r)) {
                ret = 1;
            }
        }
    } 

    free(href_s.ptr);
    free(href_r.ptr);
    
    return ret;
}


DavResource* parse_propfind_response(DavSession *sn, DavResource *root, UcxBuffer *response) {
    char *url = NULL;
    curl_easy_getinfo(sn->handle, CURLINFO_EFFECTIVE_URL, &url);
    if(!root) {
        printf("method.c: TODO: remove\n");
        root = dav_resource_new_href(sn, util_url_path(url)); // TODO: remove
    }
    
    //printf("%.*s\n\n", response->size, response->space);
    xmlDoc *doc = xmlReadMemory(response->space, response->size, url, NULL, 0);
    if(!doc) {
        // TODO: free stuff
        sn->error = DAV_ERROR;
        return NULL;
    }
    
    xmlNode *xml_root = xmlDocGetRootElement(doc);
    xmlNode *node = xml_root->children;
    while(node) {
        if(node->type == XML_ELEMENT_NODE) {
            if(xstreq(node->name, "response")) {
                parse_response_tag(root, node);
            }
        }
        node = node->next;
    }
    xmlFreeDoc(doc);
    
    return root;
}

DavResource* response2resource(DavSession *sn, ResponseTag *response, char *parent_path) {
    // create resource
    char *name = NULL;
    DavKey *key = NULL;
    if(DAV_DECRYPT_NAME(sn) && response->crypto_name && (key = dav_context_get_key(sn->context, response->crypto_key))) {
        if(!response->crypto_key) {
            // TODO: error
            fprintf(stderr, "encrypted resource without key\n");
            return NULL;
        }
        name = util_decrypt_str_k(sn, response->crypto_name, key);
        if(!name) {
            // TODO: error
            fprintf(stderr, "decrypted name is null\n");
            return NULL;
        }
    } else {
        sstr_t resname = sstr(util_resource_name(response->href));
        int nlen = 0;
        char *uname = curl_easy_unescape(
                sn->handle,
                resname.ptr,
                resname.length,
                &nlen);
        name = dav_session_strdup(sn, uname);
        curl_free(uname);
    }

    char *href = dav_session_strdup(sn, response->href);
    DavResource *res = NULL;
    if(parent_path) {
        res = dav_resource_new_full(sn, parent_path, name, href);
    } else {
        res = dav_resource_new_href(sn, href);
    }
    dav_session_free(sn, name);
    
    add_properties(res, response); 
    return res;
}

void add_properties(DavResource *res, ResponseTag *response) {
    res->iscollection = response->iscollection;
    
    // add properties
    UCX_FOREACH(elm, response->properties) {
        xmlNode *prop = elm->data;
        
        // TODO: add xml data instead of a string
        char *text = util_xml_get_text(prop);
        if(text) {
            resource_add_property(res, (char*)prop->ns->href, (char*)prop->name, text);
        }
    }
    
    set_davprops(res);
}

int parse_response_tag(DavResource *resource, xmlNode *node) {
    DavSession *sn = resource->session;
    
    //DavResource *res = resource;
    DavResource *res = NULL;
    char *href = NULL;
    UcxList *properties = NULL; // xmlNode list
    char *crypto_name = NULL; // name set by crypto-name property
    char *crypto_key = NULL;
    
    int iscollection = 0; // TODO: remove
    
    node = node->children;
    while(node) {
        if(node->type == XML_ELEMENT_NODE) {
            if(xstreq(node->name, "href")) {
                xmlNode *href_node = node->children;
                if(href_node->type != XML_TEXT_NODE) {
                    // error
                    sn->error = DAV_ERROR;
                    return 1;
                }
                //char *href = (char*)href_node->content;
                href = util_url_path((char*)href_node->content);
                
                char *href_s = util_url_decode(resource->session, href);
                char *href_r = util_url_decode(resource->session, resource->href);
                
                if(hrefeq(sn, href_s, href_r)) {
                    res = resource;
                }   
                
                free(href_s);
                free(href_r);
            } else if(xstreq(node->name, "propstat")) {
                xmlNode *n = node->children;
                xmlNode *prop_node = NULL;
                int ok = 0;
                // get the status code
                while(n) {
                    if(n->type == XML_ELEMENT_NODE) {
                        if(xstreq(n->name, "prop")) {
                            prop_node = n;
                        } else if(xstreq(n->name, "status")) {
                            xmlNode *status_node = n->children;
                            if(status_node->type != XML_TEXT_NODE) {
                                sn->error = DAV_ERROR;
                                return 1;
                            }
                            sstr_t status_str = sstr((char*)status_node->content);
                            if(status_str.length < 13) {
                                sn->error = DAV_ERROR;
                                return 1;
                            }
                            status_str = sstrsubsl(status_str, 9, 3);
                            if(!sstrcmp(status_str, S("200"))) {
                                ok = 1;
                            }
                        }
                    }    
                    n = n->next;
                }
                // if status is ok, get all properties
                if(ok) {
                    n = prop_node->children;
                    while(n) {
                        if(n->type == XML_ELEMENT_NODE) {
                            properties = ucx_list_append(properties, n);
                            if(xstreq(n->name, "resourcetype")) {
                                xmlNode *rsnode = n->children;
                                if(rsnode && rsnode->type == XML_ELEMENT_NODE) {
                                    // TODO: this is a ugly lazy hack
                                    //resource_add_property(res, "DAV:", (char*)n->name, "collection");
                                    iscollection = 1;
                                }
                            } else if(xstreq(n->ns->href, DAV_NS)) {
                                if(xstreq(n->name, "crypto-name")) {
                                    crypto_name = util_xml_get_text(n);
                                } else if(xstreq(n->name, "crypto-key")) {
                                    crypto_key = util_xml_get_text(n);
                                }
                            }
                        }
                        n = n->next;
                    }
                }
            }
        }
        
        node = node->next;
    }
    
    if(!res) {
        // create new resource object
        char *name = NULL;
        if(DAV_DECRYPT_NAME(sn) && crypto_name) {
            if(!crypto_key) {
                // TODO: error
                fprintf(stderr, "encrypted resource without key\n");
            }
            name = util_decrypt_str(sn, crypto_name, crypto_key);
            if(!name) {
                // TODO: error
                fprintf(stderr, "decrypted name is null\n");
            }
        } else {
            sstr_t resname = sstr(util_resource_name(href));
            int nlen = 0;
            char *uname = curl_easy_unescape(
                    sn->handle,
                    resname.ptr,
                    resname.length,
                    &nlen);
            name = dav_session_strdup(sn, uname);
            curl_free(uname);
        }
        
        href = dav_session_strdup(sn, href);
        res = dav_resource_new_full(sn, resource->path, name, href);
        
        dav_session_free(sn, name);
    }
    res->iscollection = iscollection;
    
    // add properties
    UCX_FOREACH(elm, properties) {
        xmlNode *prop = elm->data;
        
        // TODO: add xml data instead of a string
        char *text = util_xml_get_text(prop);
        if(text) {
            resource_add_property(res, (char*)prop->ns->href, (char*)prop->name, text);
        }
    }
    ucx_list_free(properties);
    
    set_davprops(res);
    if(res != resource) {
        resource_add_child(resource, res);
    }
    
    return 0;
}

void set_davprops(DavResource *res) {
    char *cl = dav_get_property_ns(res, "DAV:", "getcontentlength");
    char *ct = dav_get_property_ns(res, "DAV:", "getcontenttype");
    char *cd = dav_get_property_ns(res, "DAV:", "creationdate");
    char *lm = dav_get_property_ns(res, "DAV:", "getlastmodified");
    
    res->contenttype = ct;
    if(cl) {
        char *end = NULL;
        res->contentlength = strtoull(cl, &end, 0);
    }
    res->creationdate = util_parse_creationdate(cd);
    res->lastmodified = util_parse_lastmodified(lm);
}


/* ----------------------------- PROPPATCH ----------------------------- */

CURLcode do_proppatch_request(
        CURL *handle,
        UcxBuffer *request,
        UcxBuffer *response)
{
    curl_easy_setopt(handle, CURLOPT_CUSTOMREQUEST, "PROPPATCH");
    
    struct curl_slist *headers = NULL;
    headers = curl_slist_append(headers, "Content-Type: text/xml");
    curl_easy_setopt(handle, CURLOPT_HTTPHEADER, headers);
    
    curl_easy_setopt(handle, CURLOPT_UPLOAD, 1); 
    curl_easy_setopt(handle, CURLOPT_READFUNCTION, ucx_buffer_read);
    curl_easy_setopt(handle, CURLOPT_READDATA, request); 
    curl_easy_setopt(handle, CURLOPT_INFILESIZE, request->size);
    
    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, ucx_buffer_write);
    curl_easy_setopt(handle, CURLOPT_WRITEDATA, response);
    
    ucx_buffer_seek(request, 0, SEEK_SET);
    CURLcode ret = curl_easy_perform(handle);
    curl_slist_free_all(headers);
    return ret;
}

UcxBuffer* create_proppatch_request(DavResourceData *data) {
    UcxBuffer *buf = ucx_buffer_new(NULL, 512, UCX_BUFFER_AUTOEXTEND);
    sstr_t s;
    
    UcxMap *namespaces = ucx_map_new(8);
    char prefix[8];
    int pfxnum = 0;
    UCX_FOREACH(elm, data->set) {
        DavProperty *p = elm->data;
        if(strcmp(p->ns->name, "DAV:")) {
            snprintf(prefix, 8, "x%d", pfxnum++);
            ucx_map_cstr_put(namespaces, p->ns->name, prefix);
        }
    }
    UCX_FOREACH(elm, data->remove) {
        DavProperty *p = elm->data;
        if(strcmp(p->ns->name, "DAV:")) {
            snprintf(prefix, 8, "x%d", pfxnum++);
            ucx_map_cstr_put(namespaces, p->ns->name, prefix);
        }
    }
    
    s = S("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    // write root element and namespaces
    s = S("<D:propertyupdate xmlns:D=\"DAV:\"");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    UcxMapIterator mapi = ucx_map_iterator(namespaces);
    UcxKey key;
    char *pfxval;
    UCX_MAP_FOREACH(key, pfxval, mapi) {
        s = S(" xmlns:");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = sstr(pfxval);
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = S("=\"");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = sstrn(key.data, key.len);
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        s = S("\"");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
    }
    s = S(">\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    if(data->set) {
        s = S("<D:set>\n<D:prop>\n");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        UCX_FOREACH(elm, data->set) {
            DavProperty *property = elm->data;
            char *prefix = ucx_map_cstr_get(namespaces, property->ns->name);
            
            s = S("<");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = sstr(prefix);
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = S(":");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = sstr(property->name);
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = S(">");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = sstr(property->value);
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = S("</");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = sstr(prefix);
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = S(":");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = sstr(property->name);
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = S(">\n");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
        }
        s = S("</D:prop>\n</D:set>\n");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
    }
    if(data->remove) {
        s = S("<D:remove>\n<D:prop>\n");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        UCX_FOREACH(elm, data->remove) {
            DavProperty *property = elm->data;
            char *prefix = ucx_map_cstr_get(namespaces, property->ns->name);
            
            s = S("<");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = sstr(prefix);
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = S(":");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = sstr(property->name);
            ucx_buffer_write(s.ptr, 1, s.length, buf);
            s = S(" />\n");
            ucx_buffer_write(s.ptr, 1, s.length, buf);
        }
        s = S("</D:prop>\n</D:remove>\n");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
    }
    
    s = S("</D:propertyupdate>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    return buf;
}

UcxBuffer* create_crypto_proppatch_request(DavSession *sn, DavKey *key, char *name, char *hash) {
    UcxBuffer *buf = ucx_buffer_new(NULL, 512, UCX_BUFFER_AUTOEXTEND);
    sstr_t s;
    
    s = S("<?xml version=\"1.0\" encoding=\"utf-8\" ?>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    s = S("<D:propertyupdate xmlns:D=\"DAV:\" xmlns:idav=\"" DAV_NS "\">\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    s = S("<D:set>\n<D:prop>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    if(DAV_ENCRYPT_NAME(sn)) {
        s = S("<idav:crypto-name>");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        char *crname = aes_encrypt(name, strlen(name), key);
        ucx_buffer_puts(buf, crname);
        free(crname);
        s = S("</idav:crypto-name>\n");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
    }
    
    s = S("<idav:crypto-key>");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    ucx_buffer_puts(buf, key->name);
    s = S("</idav:crypto-key>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    if(hash) {
        s = S("<idav:crypto-hash>");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
        ucx_buffer_puts(buf, hash);
        s = S("</idav:crypto-hash>\n");
        ucx_buffer_write(s.ptr, 1, s.length, buf);
    }
    
    s = S("</D:prop>\n</D:set>\n</D:propertyupdate>\n");
    ucx_buffer_write(s.ptr, 1, s.length, buf);
    
    return buf;
}

/* ----------------------------- PUT ----------------------------- */

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

CURLcode do_put_request(CURL *handle, void *data, dav_read_func read_func, size_t length) {
    curl_easy_setopt(handle, CURLOPT_CUSTOMREQUEST, NULL);
    curl_easy_setopt(handle, CURLOPT_PUT, 1L);  
    curl_easy_setopt(handle, CURLOPT_UPLOAD, 1L);
    
    // clear headers
    struct curl_slist *headers = NULL;
    curl_easy_setopt(handle, CURLOPT_HTTPHEADER, headers);
    
    UcxBuffer *buf = NULL;
    if(!read_func) {
        buf = ucx_buffer_new(data, length, 0);
        buf->size = length;
        data = buf;
        read_func = (dav_read_func)ucx_buffer_read;
        curl_easy_setopt(handle, CURLOPT_INFILESIZE_LARGE, (curl_off_t)length);
    } else if(length == 0) {
        headers = curl_slist_append(headers, "Transfer-Encoding: chunked");
        curl_easy_setopt(handle, CURLOPT_INFILESIZE_LARGE, (curl_off_t)1);
        curl_easy_setopt(handle, CURLOPT_HTTPHEADER, headers);
    } else {
        curl_easy_setopt(handle, CURLOPT_INFILESIZE_LARGE, (curl_off_t)length);
    }
    
    curl_easy_setopt(handle, CURLOPT_READFUNCTION, read_func);
    curl_easy_setopt(handle, CURLOPT_READDATA, data);
    
    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, dummy_write);
    curl_easy_setopt(handle, CURLOPT_WRITEDATA, NULL);
    
    CURLcode ret = curl_easy_perform(handle);
    curl_slist_free_all(headers);
    if(buf) {
        ucx_buffer_free(buf);
    }
    return ret;
}

CURLcode do_delete_request(CURL *handle, UcxBuffer *response) {
    struct curl_slist *headers = NULL;
    curl_easy_setopt(handle, CURLOPT_HTTPHEADER, headers);
    
    curl_easy_setopt(handle, CURLOPT_CUSTOMREQUEST, "DELETE");
    curl_easy_setopt(handle, CURLOPT_PUT, 0L);  
    curl_easy_setopt(handle, CURLOPT_UPLOAD, 0L);
    
    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, ucx_buffer_write);
    curl_easy_setopt(handle, CURLOPT_WRITEDATA, response);
    
    CURLcode ret = curl_easy_perform(handle);
    return ret;
}

CURLcode do_mkcol_request(CURL *handle) { 
    struct curl_slist *headers = NULL;
    curl_easy_setopt(handle, CURLOPT_HTTPHEADER, headers);
    
    curl_easy_setopt(handle, CURLOPT_CUSTOMREQUEST, "MKCOL");
    curl_easy_setopt(handle, CURLOPT_PUT, 0L);  
    curl_easy_setopt(handle, CURLOPT_UPLOAD, 0L);
    
    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, dummy_write);
    curl_easy_setopt(handle, CURLOPT_WRITEDATA, NULL);
    
    CURLcode ret = curl_easy_perform(handle);
    return ret;
}


CURLcode do_head_request(CURL *handle) {
    curl_easy_setopt(handle, CURLOPT_CUSTOMREQUEST, "HEAD");
    curl_easy_setopt(handle, CURLOPT_PUT, 0L);  
    curl_easy_setopt(handle, CURLOPT_UPLOAD, 0L);
    curl_easy_setopt(handle, CURLOPT_NOBODY, 1L);
    
    curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, dummy_write);
    curl_easy_setopt(handle, CURLOPT_WRITEDATA, NULL);
    
    CURLcode ret = curl_easy_perform(handle);
    curl_easy_setopt(handle, CURLOPT_NOBODY, 0L);
    return ret;
}