http: improve AWS HTTP v4 Signature auth

- Add support services without region and service prefixes in
the URL endpoint (ex. Min.IO, GCP, Yandex Cloud, Mail.Ru Cloud Solutions, etc)
by providing region and service parameters via aws-sigv4 option.
- Add [:region[:service]] suffix to aws-sigv4 option;
- Fix memory allocation errors.
- Refactor memory management.
- Use Curl_http_method instead() STRING_CUSTOMREQUEST.
- Refactor canonical headers generating.
- Remove repeated sha256_to_hex() usage.
- Add some docs fixes.
- Add some codestyle fixes.
- Add overloaded strndup() for debug - curl_dbg_strndup().
- Update tests.

Closes #6524
This commit is contained in:
Dmitry Wagin 2021-01-25 17:02:09 +03:00 committed by Daniel Stenberg
parent 3c2210713e
commit 796ce293de
No known key found for this signature in database
GPG key ID: 5CC908FDB71E12C2
21 changed files with 740 additions and 255 deletions

View file

@ -26,6 +26,7 @@
#include "urldata.h"
#include "strcase.h"
#include "strdup.h"
#include "vauth/vauth.h"
#include "vauth/digest.h"
#include "http_aws_sigv4.h"
@ -43,22 +44,18 @@
#include "curl_memory.h"
#include "memdebug.h"
#define HMAC_SHA256(k, kl, d, dl, o) \
do { \
if(Curl_hmacit(Curl_HMAC_SHA256, (unsigned char *)k, \
(unsigned int)kl, \
(unsigned char *)d, \
(unsigned int)dl, o) != CURLE_OK) { \
ret = CURLE_OUT_OF_MEMORY; \
goto free_all; \
} \
#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)
#define PROVIDER_MAX_L 16
#define REQUEST_TYPE_L (PROVIDER_MAX_L + sizeof("4_request"))
/* secret key is 40 bytes long + PROVIDER_MAX_L + \0 */
#define FULL_SK_L (PROVIDER_MAX_L + 40 + 1)
static void sha256_to_hex(char *dst, unsigned char *sha, size_t dst_l)
{
int i;
@ -71,46 +68,43 @@ static void sha256_to_hex(char *dst, unsigned char *sha, size_t dst_l)
CURLcode Curl_output_aws_sigv4(struct Curl_easy *data, bool proxy)
{
CURLcode ret = CURLE_OK;
char sk[FULL_SK_L] = {0};
const char *customrequest = data->set.str[STRING_CUSTOMREQUEST];
const char *hostname = data->state.up.hostname;
struct tm info;
time_t rawtime;
/* aws is the default because some provider that are not amazone still use
* aws:amz as prefix
*/
const char *provider = data->set.str[STRING_AWS_SIGV4] ?
data->set.str[STRING_AWS_SIGV4] : "aws:amz";
size_t provider_l = strlen(provider);
char low_provider0[PROVIDER_MAX_L + 1] = {0};
char low_provider[PROVIDER_MAX_L + 1] = {0};
char up_provider[PROVIDER_MAX_L + 1] = {0};
char mid_provider[PROVIDER_MAX_L + 1] = {0};
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 *uri = NULL;
char *api_type = NULL;
char date_iso[17];
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];
char date_str[64];
const char *post_data = data->set.postfields ?
data->set.postfields : "";
const char *content_type = Curl_checkheaders(data, "Content-Type");
unsigned char sha_d[32];
char sha_hex[65];
char *cred_scope = NULL;
char *canonical_headers = NULL;
char *signed_headers = NULL;
char request_type[REQUEST_TYPE_L];
char *canonical_hdr = 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 = conn->user ? conn->user : "";
const char *passwd = conn->passwd ? conn->passwd : "";
char *secret = NULL;
unsigned char tmp_sign0[32] = {0};
unsigned char tmp_sign1[32] = {0};
char *auth = NULL;
char *tmp;
#ifdef DEBUGBUILD
char *force_timestamp;
#endif
char *auth_headers = NULL;
DEBUGASSERT(!proxy);
(void)proxy;
@ -120,214 +114,280 @@ CURLcode Curl_output_aws_sigv4(struct Curl_easy *data, bool proxy)
return CURLE_OK;
}
if(content_type) {
content_type = strchr(content_type, ':');
if(!content_type)
return CURLE_FAILED_INIT;
content_type++;
/* Skip whitespace now */
while(*content_type == ' ' || *content_type == '\t')
++content_type;
/*
* 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\n");
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';
/* Get Parameter
Google and Outscale use the same OSC or GOOG,
but Amazon use AWS and AMZ for header arguments */
tmp = strchr(provider, ':');
if(tmp) {
provider_l = tmp - provider;
if(provider_l >= PROVIDER_MAX_L) {
infof(data, "v4 signature argument string too long\n");
return CURLE_BAD_FUNCTION_ARGUMENT;
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\n");
ret = CURLE_BAD_FUNCTION_ARGUMENT;
goto fail;
}
Curl_strntolower(low_provider0, provider, provider_l);
Curl_strntoupper(up_provider, provider, provider_l);
provider = tmp + 1;
/* if "xxx:" was pass as parameter, tmp + 1 should point to \0 */
provider_l = strlen(provider);
if(provider_l >= PROVIDER_MAX_L) {
infof(data, "v4 signature argument string too long\n");
return CURLE_BAD_FUNCTION_ARGUMENT;
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\n");
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\n");
ret = CURLE_BAD_FUNCTION_ARGUMENT;
goto fail;
}
}
}
Curl_strntolower(low_provider, provider, provider_l);
Curl_strntolower(mid_provider, provider, provider_l);
}
else if(provider_l <= PROVIDER_MAX_L) {
Curl_strntolower(low_provider0, provider, provider_l);
Curl_strntolower(low_provider, provider, provider_l);
Curl_strntolower(mid_provider, provider, provider_l);
Curl_strntoupper(up_provider, provider, provider_l);
mid_provider[0] = Curl_raw_toupper(mid_provider[0]);
}
else {
infof(data, "v4 signature argument string too long\n");
return CURLE_BAD_FUNCTION_ARGUMENT;
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\n");
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\n");
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)
rawtime = 0;
clock = 0;
else
time(&clock);
#else
time(&clock);
#endif
time(&rawtime);
ret = Curl_gmtime(rawtime, &info);
ret = Curl_gmtime(clock, &tm);
if(ret != CURLE_OK) {
return ret;
goto fail;
}
if(!strftime(date_iso, sizeof(date_iso), "%Y%m%dT%H%M%SZ", &info)) {
return CURLE_OUT_OF_MEMORY;
if(!strftime(timestamp, sizeof(timestamp), "%Y%m%dT%H%M%SZ", &tm)) {
goto fail;
}
memcpy(date, date_iso, sizeof(date));
memcpy(date, timestamp, sizeof(date));
date[sizeof(date) - 1] = 0;
api_type = strdup(hostname);
if(!api_type) {
ret = CURLE_OUT_OF_MEMORY;
goto free_all;
}
tmp = strchr(api_type, '.');
if(!tmp) {
ret = CURLE_URL_MALFORMAT;
goto free_all;
}
*tmp = 0;
/* at worst, *(tmp + 1) is a '\0' */
region = tmp + 1;
tmp = strchr(region, '.');
if(!tmp) {
ret = CURLE_URL_MALFORMAT;
goto free_all;
}
*tmp = 0;
uri = data->state.up.path;
if(!curl_msnprintf(request_type, REQUEST_TYPE_L, "%s4_request",
low_provider0)) {
ret = CURLE_OUT_OF_MEMORY;
goto free_all;
}
cred_scope = curl_maprintf("%s/%s/%s/%s", date, region, api_type,
request_type);
if(!cred_scope) {
ret = CURLE_OUT_OF_MEMORY;
goto free_all;
}
if(content_type) {
canonical_hdr = curl_maprintf(
"content-type:%s\n"
"host:%s\n"
"x-%s-date:%s\n", content_type, hostname, low_provider, date_iso);
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",
low_provider);
}
else if(data->state.up.query) {
canonical_hdr = curl_maprintf(
"host:%s\n"
"x-%s-date:%s\n", hostname, low_provider, date_iso);
signed_headers = curl_maprintf("host;x-%s-date", low_provider);
provider1_low);
}
else {
ret = CURLE_FAILED_INIT;
goto free_all;
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_hdr || !signed_headers) {
ret = CURLE_OUT_OF_MEMORY;
goto free_all;
if(!canonical_headers || !signed_headers) {
goto fail;
}
Curl_sha256it(sha_d, (const unsigned char *)post_data, strlen(post_data));
sha256_to_hex(sha_hex, sha_d, sizeof(sha_hex));
Curl_sha256it(sha_hash,
(const unsigned char *) post_data, strlen(post_data));
sha256_to_hex(sha_hex, sha_hash, sizeof(sha_hex));
canonical_request = curl_maprintf(
"%s\n" /* Method */
"%s\n" /* uri */
"%s\n" /* querystring */
"%s\n" /* canonical_headers */
"%s\n" /* signed header */
"%s" /* SHA ! */,
customrequest, uri,
data->state.up.query ? data->state.up.query : "",
canonical_hdr, signed_headers, 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) {
ret = CURLE_OUT_OF_MEMORY;
goto free_all;
goto fail;
}
Curl_sha256it(sha_d, (unsigned char *)canonical_request,
strlen(canonical_request));
sha256_to_hex(sha_hex, sha_d, sizeof(sha_hex));
request_type = curl_maprintf("%s4_request", provider0_low);
if(!request_type) {
goto fail;
}
/* Google allow to use rsa key instead of HMAC, so this code might change
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 furure, but for now we support only HMAC version
*/
str_to_sign = curl_maprintf("%s4-HMAC-SHA256\n"
"%s\n%s\n%s",
up_provider, date_iso, cred_scope, sha_hex);
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) {
ret = CURLE_OUT_OF_MEMORY;
goto free_all;
goto fail;
}
curl_msnprintf(sk, sizeof(sk) - 1, "%s4%s", up_provider,
data->set.str[STRING_PASSWORD]);
secret = curl_maprintf("%s4%s", provider0_up, passwd);
if(!secret) {
goto fail;
}
HMAC_SHA256(sk, strlen(sk), date,
strlen(date), tmp_sign0);
sha256_to_hex(sha_hex, tmp_sign0, sizeof(sha_hex));
HMAC_SHA256(tmp_sign0, sizeof(tmp_sign0), region,
strlen(region), tmp_sign1);
HMAC_SHA256(tmp_sign1, sizeof(tmp_sign1), api_type,
strlen(api_type), 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);
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 = curl_maprintf("Authorization: %s4-HMAC-SHA256 Credential=%s/%s, "
"SignedHeaders=%s, Signature=%s",
up_provider, data->set.str[STRING_USERNAME], cred_scope,
signed_headers, sha_hex);
if(!auth) {
ret = CURLE_OUT_OF_MEMORY;
goto free_all;
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_msnprintf(date_str, sizeof(date_str), "X-%s-Date: %s",
mid_provider, date_iso);
data->set.headers = curl_slist_append(data->set.headers, date_str);
if(!data->set.headers) {
ret = CURLE_FAILED_INIT;
goto free_all;
}
data->set.headers = curl_slist_append(data->set.headers, auth);
if(!data->set.headers) {
ret = CURLE_FAILED_INIT;
goto free_all;
}
data->state.authhost.done = 1;
Curl_safefree(data->state.aptr.userpwd);
data->state.aptr.userpwd = auth_headers;
data->state.authhost.done = TRUE;
ret = CURLE_OK;
free_all:
free(canonical_request);
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(canonical_hdr);
free(auth);
free(cred_scope);
free(api_type);
free(secret);
return ret;
}

View file

@ -641,7 +641,8 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option, va_list param)
case CURLOPT_AWS_SIGV4:
/*
* String that holds file type of the SSL certificate to use
* String that is merged to some authentication
* parameters are used by the algorithm.
*/
result = Curl_setstropt(&data->set.str[STRING_AWS_SIGV4],
va_arg(param, char *));

View file

@ -1590,7 +1590,7 @@ enum dupstring {
STRING_COPYPOSTFIELDS, /* if POST, set the fields' values here */
STRING_AWS_SIGV4, /* Provider for V4 signature */
STRING_AWS_SIGV4, /* Parameters for V4 signature */
STRING_LAST /* not used, just an end-of-list marker */
};