curl/lib/http_aws_sigv4.c
a1346054 7cf5e8e70e
misc: fix typos in docs and comments
No user facing output from curl/libcurl is changed by this, just
comments.

Closes #7747
2021-09-23 12:57:55 +02:00

395 lines
12 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_CRYPTO_AUTH)
#include "urldata.h"
#include "strcase.h"
#include "strdup.h"
#include "vauth/vauth.h"
#include "vauth/digest.h"
#include "http_aws_sigv4.h"
#include "curl_sha256.h"
#include "transfer.h"
#include "strcase.h"
#include "parsedate.h"
#include "sendf.h"
#include <time.h>
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
#define HMAC_SHA256(k, kl, d, dl, o) \
do { \
ret = Curl_hmacit(Curl_HMAC_SHA256, \
(unsigned char *)k, \
(unsigned int)kl, \
(unsigned char *)d, \
(unsigned int)dl, o); \
if(ret != CURLE_OK) { \
goto fail; \
} \
} while(0)
static void sha256_to_hex(char *dst, unsigned char *sha, size_t dst_l)
{
int i;
DEBUGASSERT(dst_l >= 65);
for(i = 0; i < 32; ++i) {
curl_msnprintf(dst + (i * 2), dst_l - (i * 2), "%02x", sha[i]);
}
}
CURLcode Curl_output_aws_sigv4(struct Curl_easy *data, bool proxy)
{
CURLcode ret = CURLE_OUT_OF_MEMORY;
struct connectdata *conn = data->conn;
size_t len;
const char *tmp0;
const char *tmp1;
char *provider0_low = NULL;
char *provider0_up = NULL;
char *provider1_low = NULL;
char *provider1_mid = NULL;
char *region = NULL;
char *service = NULL;
const char *hostname = conn->host.name;
#ifdef DEBUGBUILD
char *force_timestamp;
#endif
time_t clock;
struct tm tm;
char timestamp[17];
char date[9];
const char *content_type = Curl_checkheaders(data, "Content-Type");
char *canonical_headers = NULL;
char *signed_headers = NULL;
Curl_HttpReq httpreq;
const char *method;
const char *post_data = data->set.postfields ? data->set.postfields : "";
unsigned char sha_hash[32];
char sha_hex[65];
char *canonical_request = NULL;
char *request_type = NULL;
char *credential_scope = NULL;
char *str_to_sign = NULL;
const char *user = data->state.aptr.user ? data->state.aptr.user : "";
const char *passwd = data->state.aptr.passwd ? data->state.aptr.passwd : "";
char *secret = NULL;
unsigned char tmp_sign0[32] = {0};
unsigned char tmp_sign1[32] = {0};
char *auth_headers = NULL;
DEBUGASSERT(!proxy);
(void)proxy;
if(Curl_checkheaders(data, "Authorization")) {
/* Authorization already present, Bailing out */
return CURLE_OK;
}
/*
* Parameters parsing
* Google and Outscale use the same OSC or GOOG,
* but Amazon uses AWS and AMZ for header arguments.
* AWS is the default because most of non-amazon providers
* are still using aws:amz as a prefix.
*/
tmp0 = data->set.str[STRING_AWS_SIGV4] ?
data->set.str[STRING_AWS_SIGV4] : "aws:amz";
tmp1 = strchr(tmp0, ':');
len = tmp1 ? (size_t)(tmp1 - tmp0) : strlen(tmp0);
if(len < 1) {
infof(data, "first provider can't be empty");
ret = CURLE_BAD_FUNCTION_ARGUMENT;
goto fail;
}
provider0_low = malloc(len + 1);
provider0_up = malloc(len + 1);
if(!provider0_low || !provider0_up) {
goto fail;
}
Curl_strntolower(provider0_low, tmp0, len);
provider0_low[len] = '\0';
Curl_strntoupper(provider0_up, tmp0, len);
provider0_up[len] = '\0';
if(tmp1) {
tmp0 = tmp1 + 1;
tmp1 = strchr(tmp0, ':');
len = tmp1 ? (size_t)(tmp1 - tmp0) : strlen(tmp0);
if(len < 1) {
infof(data, "second provider can't be empty");
ret = CURLE_BAD_FUNCTION_ARGUMENT;
goto fail;
}
provider1_low = malloc(len + 1);
provider1_mid = malloc(len + 1);
if(!provider1_low || !provider1_mid) {
goto fail;
}
Curl_strntolower(provider1_low, tmp0, len);
provider1_low[len] = '\0';
Curl_strntolower(provider1_mid, tmp0, len);
provider1_mid[0] = Curl_raw_toupper(provider1_mid[0]);
provider1_mid[len] = '\0';
if(tmp1) {
tmp0 = tmp1 + 1;
tmp1 = strchr(tmp0, ':');
len = tmp1 ? (size_t)(tmp1 - tmp0) : strlen(tmp0);
if(len < 1) {
infof(data, "region can't be empty");
ret = CURLE_BAD_FUNCTION_ARGUMENT;
goto fail;
}
region = Curl_memdup(tmp0, len + 1);
if(!region) {
goto fail;
}
region[len] = '\0';
if(tmp1) {
tmp0 = tmp1 + 1;
service = strdup(tmp0);
if(!service) {
goto fail;
}
if(strlen(service) < 1) {
infof(data, "service can't be empty");
ret = CURLE_BAD_FUNCTION_ARGUMENT;
goto fail;
}
}
}
}
else {
provider1_low = Curl_memdup(provider0_low, len + 1);
provider1_mid = Curl_memdup(provider0_low, len + 1);
if(!provider1_low || !provider1_mid) {
goto fail;
}
provider1_mid[0] = Curl_raw_toupper(provider1_mid[0]);
}
if(!service) {
tmp0 = hostname;
tmp1 = strchr(tmp0, '.');
len = tmp1 - tmp0;
if(!tmp1 || len < 1) {
infof(data, "service missing in parameters or hostname");
ret = CURLE_URL_MALFORMAT;
goto fail;
}
service = Curl_memdup(tmp0, len + 1);
if(!service) {
goto fail;
}
service[len] = '\0';
if(!region) {
tmp0 = tmp1 + 1;
tmp1 = strchr(tmp0, '.');
len = tmp1 - tmp0;
if(!tmp1 || len < 1) {
infof(data, "region missing in parameters or hostname");
ret = CURLE_URL_MALFORMAT;
goto fail;
}
region = Curl_memdup(tmp0, len + 1);
if(!region) {
goto fail;
}
region[len] = '\0';
}
}
#ifdef DEBUGBUILD
force_timestamp = getenv("CURL_FORCETIME");
if(force_timestamp)
clock = 0;
else
time(&clock);
#else
time(&clock);
#endif
ret = Curl_gmtime(clock, &tm);
if(ret != CURLE_OK) {
goto fail;
}
if(!strftime(timestamp, sizeof(timestamp), "%Y%m%dT%H%M%SZ", &tm)) {
goto fail;
}
memcpy(date, timestamp, sizeof(date));
date[sizeof(date) - 1] = 0;
if(content_type) {
content_type = strchr(content_type, ':');
if(!content_type) {
ret = CURLE_FAILED_INIT;
goto fail;
}
content_type++;
/* Skip whitespace now */
while(*content_type == ' ' || *content_type == '\t')
++content_type;
canonical_headers = curl_maprintf("content-type:%s\n"
"host:%s\n"
"x-%s-date:%s\n",
content_type,
hostname,
provider1_low, timestamp);
signed_headers = curl_maprintf("content-type;host;x-%s-date",
provider1_low);
}
else {
canonical_headers = curl_maprintf("host:%s\n"
"x-%s-date:%s\n",
hostname,
provider1_low, timestamp);
signed_headers = curl_maprintf("host;x-%s-date", provider1_low);
}
if(!canonical_headers || !signed_headers) {
goto fail;
}
Curl_sha256it(sha_hash,
(const unsigned char *) post_data, strlen(post_data));
sha256_to_hex(sha_hex, sha_hash, sizeof(sha_hex));
Curl_http_method(data, conn, &method, &httpreq);
canonical_request =
curl_maprintf("%s\n" /* HTTPRequestMethod */
"%s\n" /* CanonicalURI */
"%s\n" /* CanonicalQueryString */
"%s\n" /* CanonicalHeaders */
"%s\n" /* SignedHeaders */
"%s", /* HashedRequestPayload in hex */
method,
data->state.up.path,
data->state.up.query ? data->state.up.query : "",
canonical_headers,
signed_headers,
sha_hex);
if(!canonical_request) {
goto fail;
}
request_type = curl_maprintf("%s4_request", provider0_low);
if(!request_type) {
goto fail;
}
credential_scope = curl_maprintf("%s/%s/%s/%s",
date, region, service, request_type);
if(!credential_scope) {
goto fail;
}
Curl_sha256it(sha_hash, (unsigned char *) canonical_request,
strlen(canonical_request));
sha256_to_hex(sha_hex, sha_hash, sizeof(sha_hex));
/*
* Google allow to use rsa key instead of HMAC, so this code might change
* In the future, but for now we support only HMAC version
*/
str_to_sign = curl_maprintf("%s4-HMAC-SHA256\n" /* Algorithm */
"%s\n" /* RequestDateTime */
"%s\n" /* CredentialScope */
"%s", /* HashedCanonicalRequest in hex */
provider0_up,
timestamp,
credential_scope,
sha_hex);
if(!str_to_sign) {
goto fail;
}
secret = curl_maprintf("%s4%s", provider0_up, passwd);
if(!secret) {
goto fail;
}
HMAC_SHA256(secret, strlen(secret),
date, strlen(date), tmp_sign0);
HMAC_SHA256(tmp_sign0, sizeof(tmp_sign0),
region, strlen(region), tmp_sign1);
HMAC_SHA256(tmp_sign1, sizeof(tmp_sign1),
service, strlen(service), tmp_sign0);
HMAC_SHA256(tmp_sign0, sizeof(tmp_sign0),
request_type, strlen(request_type), tmp_sign1);
HMAC_SHA256(tmp_sign1, sizeof(tmp_sign1),
str_to_sign, strlen(str_to_sign), tmp_sign0);
sha256_to_hex(sha_hex, tmp_sign0, sizeof(sha_hex));
auth_headers = curl_maprintf("Authorization: %s4-HMAC-SHA256 "
"Credential=%s/%s, "
"SignedHeaders=%s, "
"Signature=%s\r\n"
"X-%s-Date: %s\r\n",
provider0_up,
user,
credential_scope,
signed_headers,
sha_hex,
provider1_mid,
timestamp);
if(!auth_headers) {
goto fail;
}
Curl_safefree(data->state.aptr.userpwd);
data->state.aptr.userpwd = auth_headers;
data->state.authhost.done = TRUE;
ret = CURLE_OK;
fail:
free(provider0_low);
free(provider0_up);
free(provider1_low);
free(provider1_mid);
free(region);
free(service);
free(canonical_headers);
free(signed_headers);
free(canonical_request);
free(request_type);
free(credential_scope);
free(str_to_sign);
free(secret);
return ret;
}
#endif /* !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_CRYPTO_AUTH) */