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/*
This file is part of TALER
Copyright (C) 2014-2020 Taler Systems SA
TALER 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 3, or (at your option) any later version.
TALER 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.
You should have received a copy of the GNU General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file util.c
* @brief Common utility functions; we might choose to move those to GNUnet at some point
* @author Sree Harsha Totakura <sreeharsha@totakura.in>
* @author Florian Dold
* @author Benedikt Mueller
*/
#include "platform.h"
#include "gnunet/gnunet_buffer_lib.h"
#include "taler_util.h"
#include <gcrypt.h>
/**
* Convert a buffer to an 8-character string
* representative of the contents. This is used
* for logging binary data when debugging.
*
* @param buf buffer to log
* @param buf_size number of bytes in @a buf
* @return text representation of buf, valid until next
* call to this function
*/
const char *
TALER_b2s (const void *buf,
size_t buf_size)
{
static char ret[9];
struct GNUNET_HashCode hc;
char *tmp;
GNUNET_CRYPTO_hash (buf,
buf_size,
&hc);
tmp = GNUNET_STRINGS_data_to_string_alloc (&hc,
sizeof (hc));
memcpy (ret,
tmp,
8);
GNUNET_free (tmp);
ret[8] = '\0';
return ret;
}
/**
* Obtain denomination amount from configuration file.
*
* @param cfg configuration to use
* @param section section of the configuration to access
* @param option option of the configuration to access
* @param[out] denom set to the amount found in configuration
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
TALER_config_get_denom (const struct GNUNET_CONFIGURATION_Handle *cfg,
const char *section,
const char *option,
struct TALER_Amount *denom)
{
char *str;
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_string (cfg,
section,
option,
&str))
return GNUNET_NO;
if (GNUNET_OK != TALER_string_to_amount (str,
denom))
{
GNUNET_free (str);
return GNUNET_SYSERR;
}
GNUNET_free (str);
return GNUNET_OK;
}
/**
* Set an option with an amount from the command line. A pointer to
* this function should be passed as part of the 'struct
* GNUNET_GETOPT_CommandLineOption' array to initialize options of
* this type.
*
* @param ctx command line processing context
* @param scls additional closure (will point to the `struct TALER_Amount`)
* @param option name of the option
* @param value actual value of the option as a string.
* @return #GNUNET_OK if parsing the value worked
*/
static int
set_amount (struct GNUNET_GETOPT_CommandLineProcessorContext *ctx,
void *scls,
const char *option,
const char *value)
{
struct TALER_Amount *amount = scls;
(void) ctx;
if (GNUNET_OK !=
TALER_string_to_amount (value,
amount))
{
fprintf (stderr,
_ ("Failed to parse amount in option `%s'\n"),
option);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Allow user to specify an amount on the command line.
*
* @param shortName short name of the option
* @param name long name of the option
* @param argumentHelp help text for the option argument
* @param description long help text for the option
* @param[out] amount set to the amount specified at the command line
*/
struct GNUNET_GETOPT_CommandLineOption
TALER_getopt_get_amount (char shortName,
const char *name,
const char *argumentHelp,
const char *description,
struct TALER_Amount *amount)
{
struct GNUNET_GETOPT_CommandLineOption clo = {
.shortName = shortName,
.name = name,
.argumentHelp = argumentHelp,
.description = description,
.require_argument = 1,
.processor = &set_amount,
.scls = (void *) amount
};
return clo;
}
/**
* Check if a character is reserved and should
* be urlencoded.
*
* @param c character to look at
* @return #GNUNET_YES if @a c needs to be urlencoded,
* #GNUNET_NO otherwise
*/
static bool
is_reserved (char c)
{
switch (c)
{
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
case 'a': case 'b': case 'c': case 'd': case 'e':
case 'f': case 'g': case 'h': case 'i': case 'j':
case 'k': case 'l': case 'm': case 'n': case 'o':
case 'p': case 'q': case 'r': case 's': case 't':
case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
case 'A': case 'B': case 'C': case 'D': case 'E':
case 'F': case 'G': case 'H': case 'I': case 'J':
case 'K': case 'L': case 'M': case 'N': case 'O':
case 'P': case 'Q': case 'R': case 'S': case 'T':
case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
case '-': case '.': case '_': case '~':
return GNUNET_NO;
default:
break;
}
return GNUNET_YES;
}
/**
* Get the length of a string after it has been
* urlencoded.
*
* @param s the string
* @returns the size of the urlencoded @a s
*/
static size_t
urlencode_len (const char *s)
{
size_t len = 0;
for (; *s != '\0'; len++, s++)
if (GNUNET_YES == is_reserved (*s))
len += 2;
return len;
}
/**
* URL-encode a string according to rfc3986.
*
* @param buf buffer to write the result to
* @param s string to encode
*/
static void
buffer_write_urlencode (struct GNUNET_Buffer *buf, const char *s)
{
GNUNET_buffer_ensure_remaining (buf, urlencode_len (s) + 1);
for (size_t i = 0; i < strlen (s); i++)
{
if (GNUNET_YES == is_reserved (s[i]))
GNUNET_buffer_write_fstr (buf, "%%%02X", s[i]);
else
buf->mem[buf->position++] = s[i];
}
}
/**
* URL-encode a string according to rfc3986.
*
* @param s string to encode
* @returns the urlencoded string, the caller must free it with GNUNET_free
*/
char *
TALER_urlencode (const char *s)
{
struct GNUNET_Buffer buf = { 0 };
buffer_write_urlencode (&buf, s);
return GNUNET_buffer_reap_str (&buf);
}
/**
* Make an absolute URL with query parameters.
*
* @param base_url absolute base URL to use
* @param path path of the url
* @param ... NULL-terminated key-value pairs (char *) for query parameters,
* the value will be url-encoded
* @returns the URL (must be freed with #GNUNET_free) or
* NULL if an error occured.
*/
char *
TALER_url_join (const char *base_url,
const char *path,
...)
{
unsigned int iparam = 0;
va_list args;
struct GNUNET_Buffer buf = { 0 };
size_t len;
GNUNET_assert (NULL != base_url);
GNUNET_assert (NULL != path);
if (0 == strlen (base_url))
{
/* base URL can't be empty */
GNUNET_break (0);
return NULL;
}
if ('/' != base_url[strlen (base_url) - 1])
{
/* Must be an actual base URL! */
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Base URL `%s' does not end with '/'\n",
base_url);
return NULL;
}
if ('/' == path[0])
{
/* The path must be relative. */
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Path `%s' is not relative\n",
path);
return NULL;
}
/* 1st pass: compute length */
len = strlen (base_url) + strlen (path) + 1;
va_start (args, path);
while (1)
{
char *key;
char *value;
key = va_arg (args, char *);
if (NULL == key)
break;
value = va_arg (args, char *);
if (NULL == value)
continue;
len += urlencode_len (value) + strlen (key) + 2;
}
va_end (args);
GNUNET_buffer_prealloc (&buf, len);
GNUNET_buffer_write_str (&buf, base_url);
GNUNET_buffer_write_str (&buf, path);
va_start (args, path);
while (1)
{
char *key;
char *value;
key = va_arg (args, char *);
if (NULL == key)
break;
value = va_arg (args, char *);
if (NULL == value)
continue;
GNUNET_buffer_write_str (&buf, (0 == iparam) ? "?" : "&");
iparam++;
GNUNET_buffer_write_str (&buf, key);
GNUNET_buffer_write_str (&buf, "=");
buffer_write_urlencode (&buf, value);
}
va_end (args);
return GNUNET_buffer_reap_str (&buf);
}
/**
* Make an absolute URL for the given parameters.
*
* @param proto protocol for the URL (typically https)
* @param host hostname for the URL
* @param prefix prefix for the URL
* @param path path for the URL
* @param args NULL-terminated key-value pairs (char *) for query parameters,
* the value will be url-encoded
* @returns the URL, must be freed with #GNUNET_free
*/
char *
TALER_url_absolute_raw_va (const char *proto,
const char *host,
const char *prefix,
const char *path,
va_list args)
{
struct GNUNET_Buffer buf = { 0 };
unsigned int iparam = 0;
size_t len = 0;
va_list args2;
len += strlen (proto) + strlen ("://") + strlen (host);
len += strlen (prefix) + strlen (path);
va_copy (args2, args);
while (1)
{
char *key;
char *value;
key = va_arg (args2, char *);
if (NULL == key)
break;
value = va_arg (args2, char *);
if (NULL == value)
continue;
len += urlencode_len (value) + strlen (key) + 2;
}
va_end (args2);
GNUNET_buffer_prealloc (&buf, len);
GNUNET_buffer_write_str (&buf, proto);
GNUNET_buffer_write_str (&buf, "://");
GNUNET_buffer_write_str (&buf, host);
GNUNET_buffer_write_path (&buf, prefix);
GNUNET_buffer_write_path (&buf, path);
va_copy (args2, args);
while (1)
{
char *key;
char *value;
key = va_arg (args, char *);
if (NULL == key)
break;
value = va_arg (args, char *);
if (NULL == value)
continue;
GNUNET_buffer_write_str (&buf, (0 == iparam) ? "?" : "&");
iparam++;
GNUNET_buffer_write_str (&buf, key);
GNUNET_buffer_write_str (&buf, "=");
buffer_write_urlencode (&buf, value);
}
va_end (args2);
return GNUNET_buffer_reap_str (&buf);
}
/**
* Make an absolute URL for the given parameters.
*
* @param proto protocol for the URL (typically https)
* @param host hostname for the URL
* @param prefix prefix for the URL
* @param path path for the URL
* @param args NULL-terminated key-value pairs (char *) for query parameters,
* the value will be url-encoded
* @returns the URL, must be freed with #GNUNET_free
*/
char *
TALER_url_absolute_raw (const char *proto,
const char *host,
const char *prefix,
const char *path,
...)
{
char *result;
va_list args;
va_start (args, path);
result = TALER_url_absolute_raw_va (proto, host, prefix, path, args);
va_end (args);
return result;
}
/**
* Find out if an MHD connection is using HTTPS (either
* directly or via proxy).
*
* @param connection MHD connection
* @returns GNUNET_YES if the MHD connection is using https,
* GNUNET_NO if the MHD connection is using http,
* GNUNET_SYSERR if the connection type couldn't be determined
*/
int
TALER_mhd_is_https (struct MHD_Connection *connection)
{
const union MHD_ConnectionInfo *ci;
const union MHD_DaemonInfo *di;
const char *forwarded_proto = MHD_lookup_connection_value (connection,
MHD_HEADER_KIND,
"X-Forwarded-Proto");
if (NULL != forwarded_proto)
{
if (0 == strcmp (forwarded_proto, "https"))
return GNUNET_YES;
if (0 == strcmp (forwarded_proto, "http"))
return GNUNET_NO;
GNUNET_break (0);
return GNUNET_SYSERR;
}
/* likely not reverse proxy, figure out if we are
http by asking MHD */
ci = MHD_get_connection_info (connection, MHD_CONNECTION_INFO_DAEMON);
if (NULL == ci)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
di = MHD_get_daemon_info (ci->daemon, MHD_DAEMON_INFO_FLAGS);
if (NULL == di)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
if (0 != (di->flags & MHD_USE_TLS))
return GNUNET_YES;
return GNUNET_NO;
}
/**
* Make an absolute URL for a given MHD connection.
*
* @param path path of the url
* @param ... NULL-terminated key-value pairs (char *) for query parameters,
* the value will be url-encoded
* @returns the URL, must be freed with #GNUNET_free
*/
char *
TALER_url_absolute_mhd (struct MHD_Connection *connection,
const char *path,
...)
{
/* By default we assume we're running under HTTPS */
const char *proto;
const char *host;
const char *forwarded_host;
const char *prefix;
va_list args;
char *result;
if (GNUNET_YES == TALER_mhd_is_https (connection))
proto = "https";
else
proto = "http";
host = MHD_lookup_connection_value (connection, MHD_HEADER_KIND, "Host");
forwarded_host = MHD_lookup_connection_value (connection, MHD_HEADER_KIND,
"X-Forwarded-Host");
prefix = MHD_lookup_connection_value (connection, MHD_HEADER_KIND,
"X-Forwarded-Prefix");
if (NULL == prefix)
prefix = "";
if (NULL != forwarded_host)
host = forwarded_host;
if (NULL == host)
{
/* Should never happen, at last the host header should be defined */
GNUNET_break (0);
return NULL;
}
va_start (args, path);
result = TALER_url_absolute_raw_va (proto, host, prefix, path, args);
va_end (args);
return result;
}
/**
* Prefix of PAYTO URLs.
*/
#define PAYTO "payto://"
/**
* Obtain the payment method from a @a payto_url
*
* @param payto_url the URL to parse
* @return NULL on error (malformed @a payto_url)
*/
char *
TALER_payto_get_method (const char *payto_url)
{
const char *start;
const char *end;
if (0 != strncmp (payto_url,
PAYTO,
strlen (PAYTO)))
return NULL;
start = &payto_url[strlen (PAYTO)];
end = strchr (start,
(unsigned char) '/');
if (NULL == end)
return NULL;
return GNUNET_strndup (start,
end - start);
}
/**
* Obtain the account name from a payto URL.
*
* @param payto an x-taler-bank payto URL
* @return only the account name from the @a payto URL, NULL if not an x-taler-bank
* payto URL
*/
char *
TALER_xtalerbank_account_from_payto (const char *payto)
{
const char *beg;
const char *end;
if (0 != strncasecmp (payto,
"payto://x-taler-bank/",
strlen ("payto://x-taler-bank/")))
return NULL;
beg = strchr (&payto[strlen ("payto://x-taler-bank/")],
'/');
if (NULL == beg)
return NULL;
beg++;
end = strchr (beg,
'?');
if (NULL == end)
return GNUNET_strdup (beg);
return GNUNET_strndup (beg,
end - beg);
}
/* end of util.c */
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