qfedu-basic-level/day13/documentRecognition/base/utils.h

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/**
* Copyright (c) 2017 Baidu.com, Inc. All Rights Reserved
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
*
* @author baidu aip
*/
#ifndef __AIP_UTILS_H__
#define __AIP_UTILS_H__
#include <string>
#include <fstream>
#include <ctype.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <algorithm>
#include <openssl/md5.h>
const int __BCE_VERSION__ = 1;
const int __BCE_EXPIRE__ = 1800;
namespace aip {
template<class CharT, class Traits, class Allocator>
std::basic_istream<CharT, Traits>& getall(std::basic_istream<CharT, Traits>& input,
std::basic_string<CharT, Traits, Allocator>& str) {
std::ostringstream oss;
oss << input.rdbuf();
str.assign(oss.str());
return input;
}
inline int get_file_content(const char *filename, std::string* out) {
std::ifstream in(filename, std::ios::in | std::ios::binary);
if (in) {
getall(in, *out);
return 0;
} else {
return -1;
}
}
inline std::string to_upper(std::string src)
{
std::transform(src.begin(), src.end(), src.begin(), toupper);
return src;
}
inline std::string to_lower(std::string src)
{
std::transform(src.begin(), src.end(), src.begin(), tolower);
return src;
}
inline std::string to_hex(unsigned char c, bool lower = false)
{
const std::string hex = "0123456789ABCDEF";
std::stringstream ss;
ss << hex[c >> 4] << hex[c & 0xf];
return lower ? to_lower(ss.str()) : ss.str();
}
inline time_t now()
{
return time(NULL);
}
std::string utc_time(time_t timestamp)
{
struct tm result_tm;
char buffer[32];
#ifdef _WIN32
gmtime_s(&result_tm, &timestamp);
#else
gmtime_r(&timestamp, &result_tm);
#endif
size_t size = strftime(buffer, 32, "%Y-%m-%dT%H:%M:%SZ", &result_tm);
return std::string(buffer, size);
}
void url_parse(
const std::string & url,
std::map<std::string, std::string> & params)
{
int pos = (int)url.find("?");
if (pos != -1)
{
int key_start = pos + 1,
key_len = 0,
val_start = 0;
for (int i = key_start; i <= (int)url.size(); ++i)
{
switch (url[i])
{
case '=':
key_len = i - key_start;
val_start = i + 1;
break;
case '\0':
case '&':
if (key_len != 0)
{
params[url.substr(key_start, key_len)] = url.substr(val_start, i - val_start);
key_start = i + 1;
key_len = 0;
}
break;
default:
break;
}
}
}
}
std::string url_encode(const std::string & input, bool encode_slash=true)
{
std::stringstream ss;
const char *str = input.c_str();
for (uint32_t i = 0; i < input.size(); i++)
{
unsigned char c = str[i];
if (isalnum(c) || c == '_' || c == '-' || c == '~' || c == '.' || (!encode_slash && c == '/'))
{
ss << c;
}
else
{
ss << "%" << to_hex(c);
}
}
return ss.str();
}
std::string canonicalize_params(std::map<std::string, std::string> & params)
{
std::vector<std::string> v;
v.reserve(params.size());
for (auto & it : params) {
v.push_back(url_encode(it.first) + "=" + url_encode(it.second));
}
std::sort(v.begin(), v.end());
std::string result;
for (auto & it : v)
{
result.append((result.empty() ? "" : "&") + it);
}
return result;
}
std::string canonicalize_headers(std::map<std::string, std::string> & headers)
{
std::vector<std::string> v;
v.reserve(headers.size());
for (auto & it : headers) {
v.push_back(url_encode(to_lower(it.first)) + ":" + url_encode(it.second));
}
std::sort(v.begin(), v.end());
std::string result;
for (auto & it : v)
{
result.append((result.empty() ? "" : "\n") + it);
}
return result;
}
std::string get_headers_keys(std::map<std::string, std::string> & headers)
{
std::vector<std::string> v;
v.reserve(headers.size());
for (auto & it : headers) {
v.push_back(to_lower(it.first));
}
std::string result;
for (auto & it : v)
{
result.append((result.empty() ? "" : ";") + it);
}
return result;
}
std::string get_host(const std::string & url)
{
int pos = (int)url.find("://") + 3;
return url.substr(
pos,
url.find('/', pos) - pos
);
}
std::string get_path(const std::string & url)
{
int path_start = (int)url.find('/', url.find("://") + 3);
int path_end = (int)url.find('?');
path_end = path_end == -1 ? (int)url.size() : path_end;
return url.substr(path_start, path_end - path_start);
}
std::string hmac_sha256(
const std::string & src,
const std::string & sk)
{
const EVP_MD *evp_md = EVP_sha256();
unsigned char md[EVP_MAX_MD_SIZE];
unsigned int md_len = 0;
if (HMAC(evp_md,
reinterpret_cast<const unsigned char *>(sk.data()), (int)sk.size(),
reinterpret_cast<const unsigned char *>(src.data()), src.size(),
md, &md_len) == NULL)
{
return "";
}
std::stringstream ss;
for (int i = 0; i < (int)md_len; ++i)
{
ss << to_hex(md[i], true);
}
return ss.str();
}
void sign(
std::string method,
std::string & url,
std::map<std::string, std::string> & params,
std::map<std::string, std::string> & headers,
std::string & ak,
std::string & sk)
{
url_parse(url, params);
headers["Host"] = get_host(url);
std::string timestamp = utc_time(now());
headers["x-bce-date"] = timestamp;
std::stringstream ss;
ss << "bce-auth-v" << __BCE_VERSION__ << "/" << ak << "/"
<< timestamp << "/" << __BCE_EXPIRE__;
std::string val = ss.str();
std::string sign_key = hmac_sha256(val, sk);
ss.str("");
ss << to_upper(method) << '\n' << url_encode(get_path(url), false)
<< '\n' << canonicalize_params(params)
<< '\n' << canonicalize_headers(headers);
std::string signature = hmac_sha256(ss.str(), sign_key);
ss.str("");
ss << "bce-auth-v" << __BCE_VERSION__ << "/" << ak << "/"
<< timestamp << "/" << __BCE_EXPIRE__ << "/"
<< get_headers_keys(headers) << "/" << signature;
headers["authorization"] = ss.str();
}
}
#endif