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hfile_s3.c
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hfile_s3.c
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/* hfile_s3.c -- Amazon S3 backend for low-level file streams.
Copyright (C) 2015-2017, 2019-2020 Genome Research Ltd.
Author: John Marshall <jm18@sanger.ac.uk>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE. */
#define HTS_BUILDING_LIBRARY // Enables HTSLIB_EXPORT, see htslib/hts_defs.h
#include <config.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include "hfile_internal.h"
#ifdef ENABLE_PLUGINS
#include "version.h"
#endif
#include "htslib/hts.h" // for hts_version() and hts_verbose
#include "htslib/kstring.h"
typedef struct s3_auth_data {
kstring_t id;
kstring_t token;
kstring_t secret;
kstring_t region;
kstring_t canonical_query_string;
kstring_t user_query_string;
kstring_t host;
char *bucket;
kstring_t auth_hdr;
time_t auth_time;
char date[40];
char date_long[17];
char date_short[9];
kstring_t date_html;
char mode;
char *headers[4];
int refcount;
} s3_auth_data;
#define AUTH_LIFETIME 60
#if defined HAVE_COMMONCRYPTO
#include <CommonCrypto/CommonHMAC.h>
#define DIGEST_BUFSIZ CC_SHA1_DIGEST_LENGTH
#define SHA256_DIGEST_BUFSIZE CC_SHA256_DIGEST_LENGTH
#define HASH_LENGTH_SHA256 (SHA256_DIGEST_BUFSIZE * 2) + 1
static size_t
s3_sign(unsigned char *digest, kstring_t *key, kstring_t *message)
{
CCHmac(kCCHmacAlgSHA1, key->s, key->l, message->s, message->l, digest);
return CC_SHA1_DIGEST_LENGTH;
}
static void s3_sha256(const unsigned char *in, size_t length, unsigned char *out) {
CC_SHA256(in, length, out);
}
static void s3_sign_sha256(const void *key, int key_len, const unsigned char *d, int n, unsigned char *md, unsigned int *md_len) {
CCHmac(kCCHmacAlgSHA256, key, key_len, d, n, md);
*md_len = CC_SHA256_DIGEST_LENGTH;
}
#elif defined HAVE_HMAC
#include <openssl/hmac.h>
#include <openssl/sha.h>
#define DIGEST_BUFSIZ EVP_MAX_MD_SIZE
#define SHA256_DIGEST_BUFSIZE SHA256_DIGEST_LENGTH
#define HASH_LENGTH_SHA256 (SHA256_DIGEST_BUFSIZE * 2) + 1
static size_t
s3_sign(unsigned char *digest, kstring_t *key, kstring_t *message)
{
unsigned int len;
HMAC(EVP_sha1(), key->s, key->l,
(unsigned char *) message->s, message->l, digest, &len);
return len;
}
static void s3_sha256(const unsigned char *in, size_t length, unsigned char *out) {
SHA256(in, length, out);
}
static void s3_sign_sha256(const void *key, int key_len, const unsigned char *d, int n, unsigned char *md, unsigned int *md_len) {
HMAC(EVP_sha256(), key, key_len, d, n, md, md_len);
}
#else
#error No HMAC() routine found by configure
#endif
static void
urldecode_kput(const char *s, int len, kstring_t *str)
{
char buf[3];
int i = 0;
while (i < len)
if (s[i] == '%' && i+2 < len) {
buf[0] = s[i+1], buf[1] = s[i+2], buf[2] = '\0';
kputc(strtol(buf, NULL, 16), str);
i += 3;
}
else kputc(s[i++], str);
}
static void base64_kput(const unsigned char *data, size_t len, kstring_t *str)
{
static const char base64[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
size_t i = 0;
unsigned x = 0;
int bits = 0, pad = 0;
while (bits || i < len) {
if (bits < 6) {
x <<= 8, bits += 8;
if (i < len) x |= data[i++];
else pad++;
}
bits -= 6;
kputc(base64[(x >> bits) & 63], str);
}
str->l -= pad;
kputsn("==", pad, str);
}
static int is_dns_compliant(const char *s0, const char *slim, int is_https)
{
int has_nondigit = 0, len = 0;
const char *s;
for (s = s0; s < slim; len++, s++)
if (islower_c(*s))
has_nondigit = 1;
else if (*s == '-') {
has_nondigit = 1;
if (s == s0 || s+1 == slim) return 0;
}
else if (isdigit_c(*s))
;
else if (*s == '.') {
if (is_https) return 0;
if (s == s0 || ! isalnum_c(s[-1])) return 0;
if (s+1 == slim || ! isalnum_c(s[1])) return 0;
}
else return 0;
return has_nondigit && len >= 3 && len <= 63;
}
static FILE *expand_tilde_open(const char *fname, const char *mode)
{
FILE *fp;
if (strncmp(fname, "~/", 2) == 0) {
kstring_t full_fname = { 0, 0, NULL };
const char *home = getenv("HOME");
if (! home) return NULL;
kputs(home, &full_fname);
kputs(&fname[1], &full_fname);
fp = fopen(full_fname.s, mode);
free(full_fname.s);
}
else
fp = fopen(fname, mode);
return fp;
}
static void parse_ini(const char *fname, const char *section, ...)
{
kstring_t line = { 0, 0, NULL };
int active = 1; // Start active, so global properties are accepted
char *s;
FILE *fp = expand_tilde_open(fname, "r");
if (fp == NULL) return;
while (line.l = 0, kgetline(&line, (kgets_func *) fgets, fp) >= 0)
if (line.s[0] == '[' && (s = strchr(line.s, ']')) != NULL) {
*s = '\0';
active = (strcmp(&line.s[1], section) == 0);
}
else if (active && (s = strpbrk(line.s, ":=")) != NULL) {
const char *key = line.s, *value = &s[1], *akey;
va_list args;
while (isspace_c(*key)) key++;
while (s > key && isspace_c(s[-1])) s--;
*s = '\0';
while (isspace_c(*value)) value++;
while (line.l > 0 && isspace_c(line.s[line.l-1]))
line.s[--line.l] = '\0';
va_start(args, section);
while ((akey = va_arg(args, const char *)) != NULL) {
kstring_t *avar = va_arg(args, kstring_t *);
if (strcmp(key, akey) == 0) { kputs(value, avar); break; }
}
va_end(args);
}
fclose(fp);
free(line.s);
}
static void parse_simple(const char *fname, kstring_t *id, kstring_t *secret)
{
kstring_t text = { 0, 0, NULL };
char *s;
size_t len;
FILE *fp = expand_tilde_open(fname, "r");
if (fp == NULL) return;
while (kgetline(&text, (kgets_func *) fgets, fp) >= 0)
kputc(' ', &text);
fclose(fp);
s = text.s;
while (isspace_c(*s)) s++;
kputsn(s, len = strcspn(s, " \t"), id);
s += len;
while (isspace_c(*s)) s++;
kputsn(s, strcspn(s, " \t"), secret);
free(text.s);
}
static int copy_auth_headers(s3_auth_data *ad, char ***hdrs) {
char **hdr = &ad->headers[0];
*hdrs = hdr;
*hdr = strdup(ad->date);
if (!*hdr) return -1;
hdr++;
if (ad->auth_hdr.l) {
*hdr = strdup(ad->auth_hdr.s);
if (!*hdr) { free(ad->headers[0]); return -1; }
hdr++;
}
*hdr = NULL;
return 0;
}
static void free_auth_data(s3_auth_data *ad) {
if (ad->refcount > 0) {
--ad->refcount;
return;
}
free(ad->id.s);
free(ad->token.s);
free(ad->secret.s);
free(ad->region.s);
free(ad->canonical_query_string.s);
free(ad->user_query_string.s);
free(ad->host.s);
free(ad->bucket);
free(ad->auth_hdr.s);
free(ad->date_html.s);
free(ad);
}
static int auth_header_callback(void *ctx, char ***hdrs) {
s3_auth_data *ad = (s3_auth_data *) ctx;
time_t now = time(NULL);
#ifdef HAVE_GMTIME_R
struct tm tm_buffer;
struct tm *tm = gmtime_r(&now, &tm_buffer);
#else
struct tm *tm = gmtime(&now);
#endif
kstring_t message = { 0, 0, NULL };
unsigned char digest[DIGEST_BUFSIZ];
size_t digest_len;
if (!hdrs) { // Closing connection
free_auth_data(ad);
return 0;
}
if (now - ad->auth_time < AUTH_LIFETIME) {
// Last auth string should still be valid
*hdrs = NULL;
return 0;
}
strftime(ad->date, sizeof(ad->date), "Date: %a, %d %b %Y %H:%M:%S GMT", tm);
if (!ad->id.l || !ad->secret.l) {
ad->auth_time = now;
return copy_auth_headers(ad, hdrs);
}
if (ksprintf(&message, "%s\n\n\n%s\n%s%s%s%s",
ad->mode == 'r' ? "GET" : "PUT", ad->date + 6,
ad->token.l ? "x-amz-security-token:" : "",
ad->token.l ? ad->token.s : "",
ad->token.l ? "\n" : "",
ad->bucket) < 0) {
return -1;
}
digest_len = s3_sign(digest, &ad->secret, &message);
ad->auth_hdr.l = 0;
if (ksprintf(&ad->auth_hdr, "Authorization: AWS %s:", ad->id.s) < 0)
goto fail;
base64_kput(digest, digest_len, &ad->auth_hdr);
free(message.s);
ad->auth_time = now;
return copy_auth_headers(ad, hdrs);
fail:
free(message.s);
return -1;
}
/* like a escape path but for query strings '=' and '&' are untouched */
static char *escape_query(const char *qs) {
size_t i, j = 0, length;
char *escaped;
length = strlen(qs);
if ((escaped = malloc(length * 3 + 1)) == NULL) {
return NULL;
}
for (i = 0; i < length; i++) {
int c = qs[i];
if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
c == '_' || c == '-' || c == '~' || c == '.' || c == '/' || c == '=' || c == '&') {
escaped[j++] = c;
} else {
sprintf(escaped + j, "%%%02X", c);
j += 3;
}
}
if (i != length) {
// in the case of a '?' copy the rest of the qs across unchanged
strcpy(escaped + j, qs + i);
} else {
escaped[j] = '\0';
}
return escaped;
}
static char *escape_path(const char *path) {
size_t i, j = 0, length;
char *escaped;
length = strlen(path);
if ((escaped = malloc(length * 3 + 1)) == NULL) {
return NULL;
}
for (i = 0; i < length; i++) {
int c = path[i];
if (c == '?') break; // don't escape ? or beyond
if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
c == '_' || c == '-' || c == '~' || c == '.' || c == '/') {
escaped[j++] = c;
} else {
sprintf(escaped + j, "%%%02X", c);
j += 3;
}
}
if (i != length) {
// in the case of a '?' copy the rest of the path across unchanged
strcpy(escaped + j, path + i);
} else {
escaped[j] = '\0';
}
return escaped;
}
static int is_escaped(const char *str) {
const char *c = str;
int escaped = 0;
int needs_escape = 0;
while (*c != '\0') {
if (*c == '%' && c[1] != '\0' && c[2] != '\0') {
if (isxdigit_c(c[1]) && isxdigit_c(c[2])) {
escaped = 1;
c += 3;
continue;
} else {
// only escaped if all % signs are escaped
escaped = 0;
}
}
if (!((*c >= '0' && *c <= '9') || (*c >= 'A' && *c <= 'Z')
|| (*c >= 'a' && *c <= 'z') ||
*c == '_' || *c == '-' || *c == '~' || *c == '.' || *c == '/')) {
needs_escape = 1;
}
c++;
}
return escaped || !needs_escape;
}
static int redirect_endpoint_callback(void *auth, long response,
kstring_t *header, kstring_t *url) {
s3_auth_data *ad = (s3_auth_data *)auth;
char *new_region;
char *end;
int ret = -1;
// get the new region from the reply header
if ((new_region = strstr(header->s, "x-amz-bucket-region: "))) {
new_region += strlen("x-amz-bucket-region: ");
end = new_region;
while (isalnum_c(*end) || ispunct_c(*end)) end++;
*end = 0;
if (strstr(ad->host.s, "amazonaws.com")) {
ad->region.l = 0;
kputs(new_region, &ad->region);
ad->host.l = 0;
ksprintf(&ad->host, "s3.%s.amazonaws.com", new_region);
if (ad->region.l && ad->host.l) {
url->l = 0;
kputs(ad->host.s, url);
kputsn(ad->bucket, strlen(ad->bucket), url);
if (ad->user_query_string.l) {
kputc('?', url);
kputsn(ad->user_query_string.s, ad->user_query_string.l, url);
}
ret = 0;
}
}
}
return ret;
}
static s3_auth_data * setup_auth_data(const char *s3url, const char *mode,
int sigver, kstring_t *url)
{
s3_auth_data *ad = calloc(1, sizeof(*ad));
const char *bucket, *path;
char *escaped = NULL;
kstring_t profile = { 0, 0, NULL };
size_t url_path_pos;
ptrdiff_t bucket_len;
int is_https = 1, dns_compliant;
char *query_start;
if (!ad)
return NULL;
ad->mode = strchr(mode, 'r') ? 'r' : 'w';
// Our S3 URL format is s3[+SCHEME]://[ID[:SECRET[:TOKEN]]@]BUCKET/PATH
if (s3url[2] == '+') {
bucket = strchr(s3url, ':') + 1;
if (bucket == NULL) {
free(ad);
return NULL;
}
kputsn(&s3url[3], bucket - &s3url[3], url);
is_https = strncmp(url->s, "https:", 6) == 0;
}
else {
kputs("https:", url);
bucket = &s3url[3];
}
while (*bucket == '/') kputc(*bucket++, url);
path = bucket + strcspn(bucket, "/?#@");
if (*path == '@') {
const char *colon = strpbrk(bucket, ":@");
if (*colon != ':') {
urldecode_kput(bucket, colon - bucket, &profile);
}
else {
const char *colon2 = strpbrk(&colon[1], ":@");
urldecode_kput(bucket, colon - bucket, &ad->id);
urldecode_kput(&colon[1], colon2 - &colon[1], &ad->secret);
if (*colon2 == ':')
urldecode_kput(&colon2[1], path - &colon2[1], &ad->token);
}
bucket = &path[1];
path = bucket + strcspn(bucket, "/?#");
}
else {
// If the URL has no ID[:SECRET]@, consider environment variables.
const char *v;
if ((v = getenv("AWS_ACCESS_KEY_ID")) != NULL) kputs(v, &ad->id);
if ((v = getenv("AWS_SECRET_ACCESS_KEY")) != NULL) kputs(v, &ad->secret);
if ((v = getenv("AWS_SESSION_TOKEN")) != NULL) kputs(v, &ad->token);
if ((v = getenv("AWS_DEFAULT_REGION")) != NULL) kputs(v, &ad->region);
if ((v = getenv("HTS_S3_HOST")) != NULL) kputs(v, &ad->host);
if ((v = getenv("AWS_DEFAULT_PROFILE")) != NULL) kputs(v, &profile);
else if ((v = getenv("AWS_PROFILE")) != NULL) kputs(v, &profile);
else kputs("default", &profile);
}
if (ad->id.l == 0) {
const char *v = getenv("AWS_SHARED_CREDENTIALS_FILE");
parse_ini(v? v : "~/.aws/credentials", profile.s,
"aws_access_key_id", &ad->id,
"aws_secret_access_key", &ad->secret,
"aws_session_token", &ad->token,
"region", &ad->region, NULL);
}
if (ad->id.l == 0) {
const char *v = getenv("HTS_S3_S3CFG");
parse_ini(v? v : "~/.s3cfg", profile.s, "access_key", &ad->id,
"secret_key", &ad->secret, "access_token", &ad->token,
"host_base", &ad->host,
"bucket_location", &ad->region, NULL);
}
if (ad->id.l == 0)
parse_simple("~/.awssecret", &ad->id, &ad->secret);
dns_compliant = is_dns_compliant(bucket, path, is_https);
if (ad->host.l == 0)
kputs("s3.amazonaws.com", &ad->host);
if (!dns_compliant && ad->region.l > 0
&& strcmp(ad->host.s, "s3.amazonaws.com") == 0) {
// Can avoid a redirection by including the region in the host name
// (assuming the right one has been specified)
ad->host.l = 0;
ksprintf(&ad->host, "s3.%s.amazonaws.com", ad->region.s);
}
if (ad->region.l == 0)
kputs("us-east-1", &ad->region);
if (!is_escaped(path)) {
escaped = escape_path(path);
if (escaped == NULL) {
goto error;
}
}
bucket_len = path - bucket;
// Use virtual hosted-style access if possible, otherwise path-style.
if (dns_compliant) {
size_t url_host_pos = url->l;
// Append "bucket.host" to url
kputsn_(bucket, bucket_len, url);
kputc('.', url);
kputsn(ad->host.s, ad->host.l, url);
url_path_pos = url->l;
if (sigver == 4) {
// Copy back to ad->host to use when making the signature
ad->host.l = 0;
kputsn(url->s + url_host_pos, url->l - url_host_pos, &ad->host);
}
}
else {
// Append "host/bucket" to url
kputsn(ad->host.s, ad->host.l, url);
url_path_pos = url->l;
kputc('/', url);
kputsn(bucket, bucket_len, url);
}
kputs(escaped == NULL ? path : escaped, url);
if (sigver == 4 || !dns_compliant) {
ad->bucket = malloc(url->l - url_path_pos + 1);
if (ad->bucket == NULL) {
goto error;
}
memcpy(ad->bucket, url->s + url_path_pos, url->l - url_path_pos + 1);
}
else {
ad->bucket = malloc(url->l - url_path_pos + bucket_len + 2);
if (ad->bucket == NULL) {
goto error;
}
ad->bucket[0] = '/';
memcpy(ad->bucket + 1, bucket, bucket_len);
memcpy(ad->bucket + bucket_len + 1,
url->s + url_path_pos, url->l - url_path_pos + 1);
}
// write any query strings to its own place to use later
if ((query_start = strchr(ad->bucket, '?'))) {
kputs(query_start + 1, &ad->user_query_string);
*query_start = 0;
}
free(profile.s);
free(escaped);
return ad;
error:
free(profile.s);
free(escaped);
free_auth_data(ad);
return NULL;
}
static hFILE * s3_rewrite(const char *s3url, const char *mode, va_list *argsp)
{
char *header_list[4], **header = header_list;
kstring_t url = { 0, 0, NULL };
kstring_t token_hdr = { 0, 0, NULL };
s3_auth_data *ad = setup_auth_data(s3url, mode, 2, &url);
if (!ad)
return NULL;
if (ad->token.l > 0) {
kputs("X-Amz-Security-Token: ", &token_hdr);
kputs(ad->token.s, &token_hdr);
*header++ = token_hdr.s;
}
*header = NULL;
hFILE *fp = hopen(url.s, mode, "va_list", argsp, "httphdr:v", header_list,
"httphdr_callback", auth_header_callback,
"httphdr_callback_data", ad,
"redirect_callback", redirect_endpoint_callback,
"redirect_callback_data", ad,
NULL);
if (!fp) goto fail;
free(url.s);
free(token_hdr.s);
return fp;
fail:
free(url.s);
free(token_hdr.s);
free_auth_data(ad);
return NULL;
}
/***************************************************************
AWS S3 sig version 4 writing code
****************************************************************/
static void hash_string(char *in, size_t length, char *out) {
unsigned char hashed[SHA256_DIGEST_BUFSIZE];
int i, j;
s3_sha256((const unsigned char *)in, length, hashed);
for (i = 0, j = 0; i < SHA256_DIGEST_BUFSIZE; i++, j+= 2) {
sprintf(out + j, "%02x", hashed[i]);
}
}
static void ksinit(kstring_t *s) {
s->l = 0;
s->m = 0;
s->s = NULL;
}
static void ksfree(kstring_t *s) {
free(s->s);
ksinit(s);
}
static int make_signature(s3_auth_data *ad, kstring_t *string_to_sign, char *signature_string) {
unsigned char date_key[SHA256_DIGEST_BUFSIZE];
unsigned char date_region_key[SHA256_DIGEST_BUFSIZE];
unsigned char date_region_service_key[SHA256_DIGEST_BUFSIZE];
unsigned char signing_key[SHA256_DIGEST_BUFSIZE];
unsigned char signature[SHA256_DIGEST_BUFSIZE];
const unsigned char service[] = "s3";
const unsigned char request[] = "aws4_request";
kstring_t secret_access_key = {0, 0, NULL};
unsigned int len;
unsigned int i, j;
ksprintf(&secret_access_key, "AWS4%s", ad->secret.s);
if (secret_access_key.l == 0) {
return -1;
}
s3_sign_sha256(secret_access_key.s, secret_access_key.l, (const unsigned char *)ad->date_short, strlen(ad->date_short), date_key, &len);
s3_sign_sha256(date_key, len, (const unsigned char *)ad->region.s, ad->region.l, date_region_key, &len);
s3_sign_sha256(date_region_key, len, service, 2, date_region_service_key, &len);
s3_sign_sha256(date_region_service_key, len, request, 12, signing_key, &len);
s3_sign_sha256(signing_key, len, (const unsigned char *)string_to_sign->s, string_to_sign->l, signature, &len);
for (i = 0, j = 0; i < len; i++, j+= 2) {
sprintf(signature_string + j, "%02x", signature[i]);
}
ksfree(&secret_access_key);
return 0;
}
static int make_authorisation(s3_auth_data *ad, char *http_request, char *content, kstring_t *auth) {
kstring_t signed_headers = {0, 0, NULL};
kstring_t canonical_headers = {0, 0, NULL};
kstring_t canonical_request = {0, 0, NULL};
kstring_t scope = {0, 0, NULL};
kstring_t string_to_sign = {0, 0, NULL};
char cr_hash[HASH_LENGTH_SHA256];
char signature_string[HASH_LENGTH_SHA256];
int ret = -1;
if (!ad->token.l) {
kputs("host;x-amz-content-sha256;x-amz-date", &signed_headers);
} else {
kputs("host;x-amz-content-sha256;x-amz-date;x-amz-security-token", &signed_headers);
}
if (signed_headers.l == 0) {
return -1;
}
if (!ad->token.l) {
ksprintf(&canonical_headers, "host:%s\nx-amz-content-sha256:%s\nx-amz-date:%s\n",
ad->host.s, content, ad->date_long);
} else {
ksprintf(&canonical_headers, "host:%s\nx-amz-content-sha256:%s\nx-amz-date:%s\nx-amz-security-token:%s\n",
ad->host.s, content, ad->date_long, ad->token.s);
}
if (canonical_headers.l == 0) {
goto cleanup;
}
// bucket == canonical_uri
ksprintf(&canonical_request, "%s\n%s\n%s\n%s\n%s\n%s",
http_request, ad->bucket, ad->canonical_query_string.s,
canonical_headers.s, signed_headers.s, content);
if (canonical_request.l == 0) {
goto cleanup;
}
hash_string(canonical_request.s, canonical_request.l, cr_hash);
ksprintf(&scope, "%s/%s/s3/aws4_request", ad->date_short, ad->region.s);
if (scope.l == 0) {
goto cleanup;
}
ksprintf(&string_to_sign, "AWS4-HMAC-SHA256\n%s\n%s\n%s", ad->date_long, scope.s, cr_hash);
if (string_to_sign.l == 0) {
goto cleanup;
}
if (make_signature(ad, &string_to_sign, signature_string)) {
goto cleanup;
}
ksprintf(auth, "Authorization: AWS4-HMAC-SHA256 Credential=%s/%s/%s/s3/aws4_request,SignedHeaders=%s,Signature=%s",
ad->id.s, ad->date_short, ad->region.s, signed_headers.s, signature_string);
if (auth->l == 0) {
goto cleanup;
}
ret = 0;
cleanup:
ksfree(&signed_headers);
ksfree(&canonical_headers);
ksfree(&canonical_request);
ksfree(&scope);
ksfree(&string_to_sign);
return ret;
}
static int update_time(s3_auth_data *ad) {
int ret = -1;
time_t now = time(NULL);
#ifdef HAVE_GMTIME_R
struct tm tm_buffer;
struct tm *tm = gmtime_r(&now, &tm_buffer);
#else
struct tm *tm = gmtime(&now);
#endif
if (now - ad->auth_time > AUTH_LIFETIME) {
// update timestamp
ad->auth_time = now;
if (strftime(ad->date_long, 17, "%Y%m%dT%H%M%SZ", tm) != 16) {
return -1;
}
if (strftime(ad->date_short, 9, "%Y%m%d", tm) != 8) {
return -1;;
}
ad->date_html.l = 0;
ksprintf(&ad->date_html, "x-amz-date: %s", ad->date_long);
}
if (ad->date_html.l) ret = 0;
return ret;
}
static int query_cmp(const void *p1, const void *p2) {
char **q1 = (char **)p1;
char **q2 = (char **)p2;
return strcmp(*q1, *q2);
}
/* Query strings must be in alphabetical order for authorisation */
static int order_query_string(kstring_t *qs) {
int *query_offset = NULL;
int num_queries, i;
char **queries = NULL;
kstring_t ordered = {0, 0, NULL};
char *escaped = NULL;
int ret = -1;
if ((query_offset = ksplit(qs, '&', &num_queries)) == NULL) {
return -1;
}
if ((queries = malloc(num_queries * sizeof(char*))) == NULL)
goto err;
for (i = 0; i < num_queries; i++) {
queries[i] = qs->s + query_offset[i];
}
qsort(queries, num_queries, sizeof(char *), query_cmp);
for (i = 0; i < num_queries; i++) {
if (i) {
kputs("&", &ordered);
}
kputs(queries[i], &ordered);
}
if ((escaped = escape_query(ordered.s)) == NULL)
goto err;
qs->l = 0;
kputs(escaped, qs);
ret = 0;
err:
free(ordered.s);
free(queries);
free(query_offset);
free(escaped);
return ret;
}
static int write_authorisation_callback(void *auth, char *request, kstring_t *content, char *cqs,
kstring_t *hash, kstring_t *auth_str, kstring_t *date,
kstring_t *token, int uqs) {
s3_auth_data *ad = (s3_auth_data *)auth;
char content_hash[HASH_LENGTH_SHA256];
if (request == NULL) {
// signal to free auth data
free_auth_data(ad);
return 0;
}
if (update_time(ad)) {
return -1;
}
if (content) {
hash_string(content->s, content->l, content_hash);
} else {
// empty hash
hash_string("", 0, content_hash);
}
ad->canonical_query_string.l = 0;
kputs(cqs, &ad->canonical_query_string);
if (ad->canonical_query_string.l == 0) {
return -1;
}
/* add a user provided query string, normally only useful on upload initiation */
if (uqs) {
kputs("&", &ad->canonical_query_string);
kputs(ad->user_query_string.s, &ad->canonical_query_string);
if (order_query_string(&ad->canonical_query_string)) {
return -1;
}
}
if (make_authorisation(ad, request, content_hash, auth_str)) {
return -1;
}
kputs(ad->date_html.s, date);
kputsn(content_hash, HASH_LENGTH_SHA256, hash);
if (date->l == 0 || hash->l == 0) {
return -1;
}
if (ad->token.l) {
ksprintf(token, "x-amz-security-token: %s", ad->token.s);
}
return 0;
}
static int v4_auth_header_callback(void *ctx, char ***hdrs) {
s3_auth_data *ad = (s3_auth_data *) ctx;
char content_hash[HASH_LENGTH_SHA256];
kstring_t content = {0, 0, NULL};