/* vi: set noexpandtab sw=4 sts=4: */
/* opkg_download.c - the opkg package management system

   Carl D. Worth

   Copyright (C) 2001 University of Southern California
   Copyright (C) 2008 OpenMoko Inc

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.
*/

#include "config.h"

#include <stdio.h>
#include <unistd.h>
#include <libgen.h>

#include "opkg_download.h"
#include "opkg_message.h"

#include "sprintf_alloc.h"
#include "xsystem.h"
#include "file_util.h"
#include "opkg_defines.h"
#include "libbb/libbb.h"

#ifdef HAVE_CURL
#include <curl/curl.h>
#endif

#if defined(HAVE_SSLCURL) || defined(HAVE_OPENSSL)
#include <openssl/conf.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/ssl.h>
#endif

#if defined(HAVE_GPGME)
#include <gpgme.h>
#elif defined(HAVE_OPENSSL)
#include <openssl/bio.h>
#include <openssl/objects.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/hmac.h>
#endif

#ifdef HAVE_PATHFINDER
#include "opkg_pathfinder.h"
#endif

#if defined(HAVE_OPENSSL) || defined(HAVE_SSLCURL)
static void openssl_init(void);
#endif

#ifdef HAVE_OPENSSL
static X509_STORE *setup_verify(char *CAfile, char *CApath);
#endif

#ifdef HAVE_CURL
/*
 * Make curl an instance variable so we don't have to instanciate it
 * each time
 */
static CURL *curl = NULL;
static CURL *opkg_curl_init(curl_progress_func cb, void *data);
#endif

static int
str_starts_with(const char *str, const char *prefix)
{
    return (strncmp(str, prefix, strlen(prefix)) == 0);
}

int
opkg_download(const char *src, const char *dest_file_name,
	curl_progress_func cb, void *data, const short hide_error)
{
    int err = 0;

    char *src_basec = xstrdup(src);
    char *src_base = basename(src_basec);
    char *tmp_file_location;

    opkg_msg(NOTICE,"Downloading %s.\n", src);

    if (str_starts_with(src, "file:")) {
	const char *file_src = src + 5;
	opkg_msg(INFO, "Copying %s to %s...", file_src, dest_file_name);
	err = file_copy(file_src, dest_file_name);
	opkg_msg(INFO, "Done.\n");
        free(src_basec);
	return err;
    }

    sprintf_alloc(&tmp_file_location, "%s/%s", conf->tmp_dir, src_base);
    free(src_basec);
    err = unlink(tmp_file_location);
    if (err && errno != ENOENT) {
	opkg_perror(ERROR, "Failed to unlink %s", tmp_file_location);
	free(tmp_file_location);
	return -1;
    }

    if (conf->http_proxy) {
	opkg_msg(DEBUG, "Setting environment variable: http_proxy = %s.\n",
		conf->http_proxy);
	setenv("http_proxy", conf->http_proxy, 1);
    }
    if (conf->ftp_proxy) {
	opkg_msg(DEBUG, "Setting environment variable: ftp_proxy = %s.\n",
		conf->ftp_proxy);
	setenv("ftp_proxy", conf->ftp_proxy, 1);
    }
    if (conf->no_proxy) {
	opkg_msg(DEBUG,"Setting environment variable: no_proxy = %s.\n",
		conf->no_proxy);
	setenv("no_proxy", conf->no_proxy, 1);
    }

#ifdef HAVE_CURL
    CURLcode res;
    FILE * file = fopen (tmp_file_location, "w");

    curl = opkg_curl_init (cb, data);
    if (curl)
    {
	curl_easy_setopt (curl, CURLOPT_URL, src);
	curl_easy_setopt (curl, CURLOPT_WRITEDATA, file);

	res = curl_easy_perform (curl);
	fclose (file);
	if (res)
	{
	    long error_code;
	    curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &error_code);
	    opkg_msg(hide_error?DEBUG2:ERROR, "Failed to download %s: %s.\n",
		    src, curl_easy_strerror(res));
	    free(tmp_file_location);
	    return -1;
	}

    }
    else
    {
	free(tmp_file_location);
	return -1;
    }
#else
    {
      int res;
      const char *argv[8];
      int i = 0;

      argv[i++] = "wget";
      argv[i++] = "-q";
      if (conf->http_proxy || conf->ftp_proxy) {
	argv[i++] = "-Y";
	argv[i++] = "on";
      }
      argv[i++] = "-O";
      argv[i++] = tmp_file_location;
      argv[i++] = src;
      argv[i++] = NULL;
      res = xsystem(argv);

      if (res) {
	opkg_msg(ERROR, "Failed to download %s, wget returned %d.\n", src, res);
	free(tmp_file_location);
	return -1;
      }
    }
#endif

    err = file_move(tmp_file_location, dest_file_name);

    free(tmp_file_location);

    return err;
}

static int
opkg_download_cache(const char *src, const char *dest_file_name,
	curl_progress_func cb, void *data)
{
    char *cache_name = xstrdup(src);
    char *cache_location, *p;
    int err = 0;

    if (!conf->cache || str_starts_with(src, "file:")) {
	err = opkg_download(src, dest_file_name, cb, data, 0);
	goto out1;
    }

    if(!file_is_dir(conf->cache)){
	    opkg_msg(ERROR, "%s is not a directory.\n",
			    conf->cache);
	    err = 1;
	    goto out1;
    }

    for (p = cache_name; *p; p++)
	if (*p == '/')
	    *p = ',';	/* looks nicer than | or # */

    sprintf_alloc(&cache_location, "%s/%s", conf->cache, cache_name);
    if (file_exists(cache_location))
	opkg_msg(NOTICE, "Copying %s.\n", cache_location);
    else {
       /* cache file with funky name not found, try simple name */
        free(cache_name);
        char *filename = strrchr(dest_file_name,'/');
        if (filename)
           cache_name = xstrdup(filename+1); // strip leading '/'
        else
           cache_name = xstrdup(dest_file_name);
        free(cache_location);
        sprintf_alloc(&cache_location, "%s/%s", conf->cache, cache_name);
        if (file_exists(cache_location))
           opkg_msg(NOTICE, "Copying %s.\n", cache_location);
        else  {
 	    err = opkg_download(src, cache_location, cb, data, 0);
	    if (err) {
	       (void) unlink(cache_location);
	       goto out2;
	  }
	}
    }

    err = file_copy(cache_location, dest_file_name);


out2:
    free(cache_location);
out1:
    free(cache_name);
    return err;
}

int
opkg_download_pkg(pkg_t *pkg, const char *dir)
{
    int err;
    char *url;
    char *stripped_filename;

    if (pkg->src == NULL) {
	opkg_msg(ERROR, "Package %s is not available from any configured src.\n",
		pkg->name);
	return -1;
    }
    if (pkg->filename == NULL) {
	opkg_msg(ERROR, "Package %s does not have a valid filename field.\n",
		pkg->name);
	return -1;
    }

    sprintf_alloc(&url, "%s/%s", pkg->src->value, pkg->filename);

    /* The pkg->filename might be something like
       "../../foo.opk". While this is correct, and exactly what we
       want to use to construct url above, here we actually need to
       use just the filename part, without any directory. */

    stripped_filename = strrchr(pkg->filename, '/');
    if ( ! stripped_filename )
        stripped_filename = pkg->filename;

    sprintf_alloc(&pkg->local_filename, "%s/%s", dir, stripped_filename);

    err = opkg_download_cache(url, pkg->local_filename, NULL, NULL);
    free(url);

    return err;
}

/*
 * Downloads file from url, installs in package database, return package name.
 */
int
opkg_prepare_url_for_install(const char *url, char **namep)
{
     int err = 0;
     pkg_t *pkg, *tmp;

     pkg = pkg_new();

     if (str_starts_with(url, "http://")
	 || str_starts_with(url, "ftp://")) {
	  char *tmp_file;
	  char *file_basec = xstrdup(url);
	  char *file_base = basename(file_basec);

	  sprintf_alloc(&tmp_file, "%s/%s", conf->tmp_dir, file_base);
	  err = opkg_download(url, tmp_file, NULL, NULL, 0);
	  if (err)
	       return err;

	  err = pkg_init_from_file(pkg, tmp_file);
	  if (err)
	       return err;

	  free(tmp_file);
	  free(file_basec);

     } else if (strcmp(&url[strlen(url) - 4], OPKG_PKG_EXTENSION) == 0
                || strcmp(&url[strlen(url) - 4], IPKG_PKG_EXTENSION) == 0
		|| strcmp(&url[strlen(url) - 4], DPKG_PKG_EXTENSION) == 0) {

	  err = pkg_init_from_file(pkg, url);
	  if (err)
	       return err;
	  opkg_msg(DEBUG2, "Package %s provided by hand (%s).\n",
		  pkg->name, pkg->local_filename);
          pkg->provided_by_hand = 1;
     } else if (conf->force_reinstall) {
	  /* Reload the given package from its package file into a new package
	   * object. This new object can then be marked as force_reinstall and
	   * the reinstall should go ahead like an upgrade.
	   */
	  tmp = pkg_hash_fetch_best_installation_candidate_by_name(url);
	  if (!tmp) {
	       opkg_msg(NOTICE, "Unknown package '%s'.\n", url);
	       return -1;
	  }
	  err = opkg_download_pkg(tmp, conf->tmp_dir);
	  if (err)
	       return err;
	  err = pkg_init_from_file(pkg, tmp->local_filename);
	  if (err)
	       return err;
     } else {
       pkg_deinit(pkg);
       free(pkg);
       return 0;
     }

     pkg->dest = conf->default_dest;
     pkg->state_want = SW_INSTALL;
     pkg->state_flag |= SF_PREFER;

     if (conf->force_reinstall)
	 pkg->force_reinstall = 1;

     hash_insert_pkg(pkg, 1);

     if (namep) {
	  *namep = pkg->name;
     }
     return 0;
}

int
opkg_verify_file (char *text_file, char *sig_file)
{
#if defined HAVE_GPGME
    if (conf->check_signature == 0 )
        return 0;
    int status = -1;
    gpgme_ctx_t ctx;
    gpgme_data_t sig, text, key;
    gpgme_error_t err;
    gpgme_verify_result_t result;
    gpgme_signature_t s;
    char *trusted_path = NULL;

    gpgme_check_version (NULL);

    err = gpgme_new (&ctx);

    if (err)
	return -1;

    trusted_path = root_filename_alloc("/etc/opkg/trusted.gpg");
    err = gpgme_data_new_from_file (&key, trusted_path, 1);
    free (trusted_path);
    if (err)
    {
      return -1;
    }
    err = gpgme_op_import (ctx, key);
    if (err)
    {
      gpgme_data_release (key);
      return -1;
    }
    gpgme_data_release (key);

    err = gpgme_data_new_from_file (&sig, sig_file, 1);
    if (err)
    {
	gpgme_release (ctx);
	return -1;
    }

    err = gpgme_data_new_from_file (&text, text_file, 1);
    if (err)
    {
        gpgme_data_release (sig);
	gpgme_release (ctx);
	return -1;
    }

    err = gpgme_op_verify (ctx, sig, text, NULL);

    result = gpgme_op_verify_result (ctx);
    if (!result)
	return -1;

    /* see if any of the signitures matched */
    s = result->signatures;
    while (s)
    {
	status = gpg_err_code (s->status);
	if (status == GPG_ERR_NO_ERROR)
	    break;
	s = s->next;
    }


    gpgme_data_release (sig);
    gpgme_data_release (text);
    gpgme_release (ctx);

    return status;
#elif defined HAVE_OPENSSL
    X509_STORE *store = NULL;
    PKCS7 *p7 = NULL;
    BIO *in = NULL, *indata = NULL;

    // Sig check failed by default !
    int status = -1;

    openssl_init();

    // Set-up the key store
    if(!(store = setup_verify(conf->signature_ca_file, conf->signature_ca_path))){
        opkg_msg(ERROR, "Can't open CA certificates.\n");
        goto verify_file_end;
    }

    // Open a BIO to read the sig file
    if (!(in = BIO_new_file(sig_file, "rb"))){
        opkg_msg(ERROR, "Can't open signature file %s.\n", sig_file);
        goto verify_file_end;
    }

    // Read the PKCS7 block contained in the sig file
    p7 = PEM_read_bio_PKCS7(in, NULL, NULL, NULL);
    if(!p7){
        opkg_msg(ERROR, "Can't read signature file %s (Corrupted ?).\n",
		sig_file);
        goto verify_file_end;
    }
#if defined(HAVE_PATHFINDER)
    if(conf->check_x509_path){
	if(!pkcs7_pathfinder_verify_signers(p7)){
	    opkg_msg(ERROR, "pkcs7_pathfinder_verify_signers: "
		    "Path verification failed.\n");
	    goto verify_file_end;
	}
    }
#endif

    // Open the Package file to authenticate
    if (!(indata = BIO_new_file(text_file, "rb"))){
        opkg_msg(ERROR, "Can't open file %s.\n", text_file);
        goto verify_file_end;
    }

    // Let's verify the autenticity !
    if (PKCS7_verify(p7, NULL, store, indata, NULL, PKCS7_BINARY) != 1){
        // Get Off My Lawn!
        opkg_msg(ERROR, "Verification failure.\n");
    }else{
        // Victory !
        status = 0;
    }

verify_file_end:
    BIO_free(in);
    BIO_free(indata);
    PKCS7_free(p7);
    X509_STORE_free(store);

    return status;
#else
    /* mute `unused variable' warnings. */
    (void) sig_file;
    (void) text_file;
    (void) conf;
    return 0;
#endif
}


#if defined(HAVE_OPENSSL) || defined(HAVE_SSLCURL)
static void openssl_init(void){
    static int init = 0;

    if(!init){
	OPENSSL_config(NULL);
        OpenSSL_add_all_algorithms();
        ERR_load_crypto_strings();
        init = 1;
    }
}

#endif


#if defined HAVE_OPENSSL
static X509_STORE *
setup_verify(char *CAfile, char *CApath)
{
    X509_STORE *store = NULL;
    X509_LOOKUP *lookup = NULL;

    if(!(store = X509_STORE_new())){
        // Something bad is happening...
        goto end;
    }

    // adds the X509 file lookup method
    lookup = X509_STORE_add_lookup(store,X509_LOOKUP_file());
    if (lookup == NULL){
        goto end;
    }

    // Autenticating against one CA file
    if (CAfile) {
        if(!X509_LOOKUP_load_file(lookup,CAfile,X509_FILETYPE_PEM)) {
            // Invalid CA => Bye bye
            opkg_msg(ERROR, "Error loading file %s.\n", CAfile);
            goto end;
        }
    } else {
        X509_LOOKUP_load_file(lookup,NULL,X509_FILETYPE_DEFAULT);
    }

    // Now look into CApath directory if supplied
    lookup = X509_STORE_add_lookup(store,X509_LOOKUP_hash_dir());
    if (lookup == NULL){
        goto end;
    }

    if (CApath) {
        if(!X509_LOOKUP_add_dir(lookup,CApath,X509_FILETYPE_PEM)) {
            opkg_msg(ERROR, "Error loading directory %s.\n", CApath);
            goto end;
        }
    } else {
        X509_LOOKUP_add_dir(lookup,NULL,X509_FILETYPE_DEFAULT);
    }

    // All right !
    ERR_clear_error();
    return store;

end:

    X509_STORE_free(store);
    return NULL;

}

#endif

void opkg_curl_cleanup(void){
#ifdef HAVE_CURL
    if(curl != NULL){
	curl_easy_cleanup (curl);
	curl = NULL;
    }
#endif
}

#ifdef HAVE_CURL
static CURL *
opkg_curl_init(curl_progress_func cb, void *data)
{

    if(curl == NULL){
	curl = curl_easy_init();

#ifdef HAVE_SSLCURL
	openssl_init();

	if (conf->ssl_engine) {

	    /* use crypto engine */
	    if (curl_easy_setopt(curl, CURLOPT_SSLENGINE, conf->ssl_engine) != CURLE_OK){
		opkg_msg(ERROR, "Can't set crypto engine '%s'.\n",
			conf->ssl_engine);

		opkg_curl_cleanup();
		return NULL;
	    }
	    /* set the crypto engine as default */
	    if (curl_easy_setopt(curl, CURLOPT_SSLENGINE_DEFAULT, 1L) != CURLE_OK){
		opkg_msg(ERROR, "Can't set crypto engine '%s' as default.\n",
			conf->ssl_engine);

		opkg_curl_cleanup();
		return NULL;
	    }
	}

	/* cert & key can only be in PEM case in the same file */
	if(conf->ssl_key_passwd){
	    if (curl_easy_setopt(curl, CURLOPT_SSLKEYPASSWD, conf->ssl_key_passwd) != CURLE_OK)
	    {
	        opkg_msg(DEBUG, "Failed to set key password.\n");
	    }
	}

	/* sets the client certificate and its type */
	if(conf->ssl_cert_type){
	    if (curl_easy_setopt(curl, CURLOPT_SSLCERTTYPE, conf->ssl_cert_type) != CURLE_OK)
	    {
	        opkg_msg(DEBUG, "Failed to set certificate format.\n");
	    }
	}
	/* SSL cert name isn't mandatory */
	if(conf->ssl_cert){
	        curl_easy_setopt(curl, CURLOPT_SSLCERT, conf->ssl_cert);
	}

	/* sets the client key and its type */
	if(conf->ssl_key_type){
	    if (curl_easy_setopt(curl, CURLOPT_SSLKEYTYPE, conf->ssl_key_type) != CURLE_OK)
	    {
	        opkg_msg(DEBUG, "Failed to set key format.\n");
	    }
	}
	if(conf->ssl_key){
	    if (curl_easy_setopt(curl, CURLOPT_SSLKEY, conf->ssl_key) != CURLE_OK)
	    {
	        opkg_msg(DEBUG, "Failed to set key.\n");
	    }
	}

	/* Should we verify the peer certificate ? */
	if(conf->ssl_dont_verify_peer){
	    /*
	     * CURLOPT_SSL_VERIFYPEER default is nonzero (curl => 7.10)
	     */
	    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
	}else{
#ifdef HAVE_PATHFINDER
	    if(conf->check_x509_path){
    	        if (curl_easy_setopt(curl, CURLOPT_SSL_CTX_FUNCTION, curl_ssl_ctx_function) != CURLE_OK){
		    opkg_msg(DEBUG, "Failed to set ssl path verification callback.\n");
		}else{
		    curl_easy_setopt(curl, CURLOPT_SSL_CTX_DATA, NULL);
		}
	    }
#endif
	}

	/* certification authority file and/or path */
	if(conf->ssl_ca_file){
	    curl_easy_setopt(curl, CURLOPT_CAINFO, conf->ssl_ca_file);
	}
	if(conf->ssl_ca_path){
	    curl_easy_setopt(curl, CURLOPT_CAPATH, conf->ssl_ca_path);
	}
#endif

	curl_easy_setopt (curl, CURLOPT_FOLLOWLOCATION, 1);
	curl_easy_setopt (curl, CURLOPT_FAILONERROR, 1);
	if (conf->http_proxy || conf->ftp_proxy)
	{
	    char *userpwd;
	    sprintf_alloc (&userpwd, "%s:%s", conf->proxy_user,
		    conf->proxy_passwd);
	    curl_easy_setopt(curl, CURLOPT_PROXYUSERPWD, userpwd);
	    free (userpwd);
	}
    }

    curl_easy_setopt (curl, CURLOPT_NOPROGRESS, (cb == NULL));
    if (cb)
    {
	curl_easy_setopt (curl, CURLOPT_PROGRESSDATA, data);
	curl_easy_setopt (curl, CURLOPT_PROGRESSFUNCTION, cb);
    }

    return curl;

}
#endif