<directivesynopsis>
<name>HttpProtocolOptions</name>
<description>Modify restrictions on HTTP Request Messages</description>
-<syntax>HttpProtocolOptions [Strict|Unsafe] [StrictURL|UnsafeURL]
- [RegisteredMethods|LenientMethods] [Allow0.9|Require1.0]</syntax>
-<default>HttpProtocolOptions Strict StrictURL LenientMethods Allow0.9</default>
+<syntax>HttpProtocolOptions [Strict|Unsafe] [RegisteredMethods|LenientMethods]
+ [Allow0.9|Require1.0]</syntax>
+<default>HttpProtocolOptions Strict LenientMethods Allow0.9</default>
<contextlist><context>server config</context>
<context>virtual host</context></contextlist>
<compatibility>2.2.32 or 2.4.24 and later</compatibility>
(<a href="https://tools.ietf.org/html/rfc7230#section-3.2"
>RFC 7230 §3.2</a>), which are now applied by default or using
the <code>Strict</code> option. Due to legacy modules, applications or
- custom user-agents which must be deperecated, <code>Unsafe</code>
- and <code>UnsafeURL</code> options have been added to revert to the legacy
- behaviors. These rules are applied prior to request processing, so must be
- configured at the global or default (first) matching virtual host section,
- by IP/port interface and not by name, to be honored.</p>
+ custom user-agents which must be deperecated the <code>Unsafe</code>
+ option has been added to revert to the legacy behaviors. These rules
+ are applied prior to request processing, so must be configured at the
+ global or default (first) matching virtual host section, by IP/port
+ interface (and not by name) to be honored.</p>
<p>Prior to the introduction of this directive, the Apache HTTP Server
request message parsers were tolerant of a number of forms of input
mode, and the strict whitespace suggested by section 3.5 is enforced
and cannot be relaxed.</p>
- <p><a href="https://tools.ietf.org/html/rfc3986#section-2.2"
- >RFC 3986 §2.2 and 2.3</a> define "Reserved Characters" and
- "Unreserved Characters". All other character octets are required to
- be %XX encoded under this spec, and RFC7230 defers to these requirements.
- By default the <code>StrictURI</code> option will reject all requests
- containing invalid characters. This rule can be relaxed with the
- <code>UnsafeURI</code> option to support badly written user-agents.</p>
-
<p>Users are strongly cautioned against toggling the <code>Unsafe</code>
- or <code>UnsafeURI</code> modes of operation, particularly on
- outward-facing, publicly accessible server deployments.
- If an interface is required for faulty monitoring or other custom service
- consumers running on an intranet, users should toggle only those Unsafe
- options which are necessary, and only on a specific virtual host configured
- to service only their internal private network.</p>
+ mode of operation, particularly on outward-facing, publicly accessible
+ server deployments. If an interface is required for faulty monitoring
+ or other custom service consumers running on an intranet, users should
+ toggle the Unsafe option only on a specific virtual host configured
+ to service their internal private network.</p>
<p>Reviewing the messages logged to the <directive>ErrorLog</directive>,
configured with <directive>LogLevel</directive> <code>debug</code> level,
/**
* Parse a chunk line with optional extension, detect overflow.
- * There are two error cases:
+ * There are several error cases:
+ * 1) If the chunk link is misformatted, APR_EINVAL is returned.
* 1) If the conversion would require too many bits, APR_EGENERAL is returned.
* 2) If the conversion used the correct number of bits, but an overflow
* caused only the sign bit to flip, then APR_ENOSPC is returned.
- * In general, any negative number can be considered an overflow error.
+ * A negative chunk length always indicates an overflow error.
*/
static apr_status_t parse_chunk_size(http_ctx_t *ctx, const char *buffer,
- apr_size_t len, int linelimit)
+ apr_size_t len, int linelimit, int strict)
{
apr_size_t i = 0;
if (ctx->state == BODY_CHUNK_END
|| ctx->state == BODY_CHUNK_END_LF) {
if (c == LF) {
+ if (strict && (ctx->state != BODY_CHUNK_END_LF)) {
+ /*
+ * CR missing before LF.
+ */
+ return APR_EINVAL;
+ }
ctx->state = BODY_CHUNK;
}
else if (c == CR && ctx->state == BODY_CHUNK_END) {
}
else {
/*
- * LF expected.
+ * CRLF expected.
*/
return APR_EINVAL;
}
}
if (c == LF) {
+ if (strict && (ctx->state != BODY_CHUNK_LF)) {
+ /*
+ * CR missing before LF.
+ */
+ return APR_EINVAL;
+ }
if (ctx->remaining) {
ctx->state = BODY_CHUNK_DATA;
}
}
else if (ctx->state == BODY_CHUNK_EXT) {
/*
- * Control chars (but tabs) are invalid.
+ * Control chars (excluding tabs) are invalid.
+ * TODO: more precisely limit input
*/
if (c != '\t' && apr_iscntrl(c)) {
return APR_EINVAL;
}
}
- else if (c == ' ' || c == '\t') {
+ else if (!strict && (c == ' ' || c == '\t')) {
/* Be lenient up to 10 BWS (term from rfc7230 - 3.2.3).
*/
ctx->state = BODY_CHUNK_CR;
ap_input_mode_t mode, apr_read_type_e block,
apr_off_t readbytes)
{
- core_server_config *conf;
+ core_server_config *conf =
+ (core_server_config *) ap_get_module_config(f->r->server->module_config,
+ &core_module);
+ int strict = (conf->http_conformance != AP_HTTP_CONFORMANCE_UNSAFE);
apr_bucket *e;
http_ctx_t *ctx = f->ctx;
apr_status_t rv;
int again;
- conf = (core_server_config *)
- ap_get_module_config(f->r->server->module_config, &core_module);
-
/* just get out of the way of things we don't want. */
if (mode != AP_MODE_READBYTES && mode != AP_MODE_GETLINE) {
return ap_get_brigade(f->next, b, mode, block, readbytes);
if (rv == APR_SUCCESS) {
rv = parse_chunk_size(ctx, buffer, len,
- f->r->server->limit_req_fieldsize);
+ f->r->server->limit_req_fieldsize, strict);
}
if (rv != APR_SUCCESS) {
ap_log_rerror(APLOG_MARK, APLOG_INFO, rv, f->r, APLOGNO(01590)
struct check_header_ctx {
request_rec *r;
- int error;
+ int strict;
};
/* check a single header, to be used with apr_table_do() */
static int check_header(void *arg, const char *name, const char *val)
{
struct check_header_ctx *ctx = arg;
+ const char *test;
+
if (name[0] == '\0') {
- ctx->error = 1;
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, ctx->r, APLOGNO(02428)
"Empty response header name, aborting request");
return 0;
}
- if (ap_has_cntrl(name)) {
- ctx->error = 1;
+
+ if (ctx->strict) {
+ test = ap_scan_http_token(name);
+ }
+ else {
+ test = ap_scan_vchar_obstext(name);
+ }
+ if (*test) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, ctx->r, APLOGNO(02429)
- "Response header name '%s' contains control "
+ "Response header name '%s' contains invalid "
"characters, aborting request",
name);
return 0;
}
- if (ap_has_cntrl(val)) {
- ctx->error = 1;
+
+ if (ctx->strict) {
+ test = ap_scan_http_field_content(val);
+ }
+ else {
+ /* Simply terminate scanning on a CTL char, allowing whitespace */
+ test = val;
+ do {
+ test = ap_scan_vchar_obstext(test);
+ } while (*test == ' ' || *test == '\t');
+ }
+ if (*test) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, ctx->r, APLOGNO(02430)
- "Response header '%s' contains control characters, "
- "aborting request: %s",
+ "Response header '%s' value of '%s' contains invalid "
+ "characters, aborting request",
name, val);
return 0;
}
static APR_INLINE int check_headers(request_rec *r)
{
const char *loc;
- struct check_header_ctx ctx = { 0, 0 };
+ struct check_header_ctx ctx;
+ core_server_config *conf =
+ ap_get_core_module_config(r->server->module_config);
ctx.r = r;
- apr_table_do(check_header, &ctx, r->headers_out, NULL);
- if (ctx.error)
+ ctx.strict = (conf->http_conformance != AP_HTTP_CONFORMANCE_UNSAFE);
+ if (!apr_table_do(check_header, &ctx, r->headers_out, NULL))
return 0; /* problem has been logged by check_header() */
if ((loc = apr_table_get(r->headers_out, "Location")) != NULL) {
header_filter_ctx *ctx = f->ctx;
const char *ctype;
ap_bucket_error *eb = NULL;
- core_server_config *conf;
AP_DEBUG_ASSERT(!r->main);
r->headers_out);
}
- conf = ap_get_core_module_config(r->server->module_config);
- if (conf->http_conformance != AP_HTTP_CONFORMANCE_UNSAFE) {
- int ok = check_headers(r);
- if (!ok) {
- ap_die(HTTP_INTERNAL_SERVER_ERROR, r);
- return AP_FILTER_ERROR;
- }
+ if (!check_headers(r)) {
+ ap_die(HTTP_INTERNAL_SERVER_ERROR, r);
+ return AP_FILTER_ERROR;
}
/*
if (virt->http_conformance != AP_HTTP_CONFORMANCE_UNSET)
conf->http_conformance = virt->http_conformance;
- if (virt->http_stricturi != AP_HTTP_URI_UNSET)
- conf->http_stricturi = virt->http_stricturi;
-
if (virt->http_methods != AP_HTTP_METHODS_UNSET)
conf->http_methods = virt->http_methods;
conf->http_conformance |= AP_HTTP_CONFORMANCE_STRICT;
else if (strcasecmp(arg, "unsafe") == 0)
conf->http_conformance |= AP_HTTP_CONFORMANCE_UNSAFE;
- else if (strcasecmp(arg, "stricturi") == 0)
- conf->http_stricturi |= AP_HTTP_URI_STRICT;
- else if (strcasecmp(arg, "unsafeuri") == 0)
- conf->http_stricturi |= AP_HTTP_URI_UNSAFE;
else if (strcasecmp(arg, "registeredmethods") == 0)
conf->http_methods |= AP_HTTP_METHODS_REGISTERED;
else if (strcasecmp(arg, "lenientmethods") == 0)
else
return "HttpProtocolOptions accepts "
"'Unsafe' or 'Strict' (default), "
- "'UnsafeURI' or 'StrictURI' (default), "
"'RegisteredMethods' or 'LenientMethods' (default), and "
"'Require1.0' or 'Allow0.9' (default)";
return "HttpProtocolOptions 'Allow0.9' and 'Require1.0'"
" are mutually exclusive";
- if ((conf->http_stricturi & AP_HTTP_URI_STRICT)
- && (conf->http_stricturi & AP_HTTP_URI_UNSAFE))
- return "HttpProtocolOptions 'StrictURI' and 'UnsafeURI'"
- " are mutually exclusive";
-
if ((conf->http_conformance & AP_HTTP_CONFORMANCE_STRICT)
&& (conf->http_conformance & AP_HTTP_CONFORMANCE_UNSAFE))
return "HttpProtocolOptions 'Strict' and 'Unsafe'"
AP_INIT_FLAG("MergeTrailers", set_merge_trailers, NULL, RSRC_CONF,
"merge request trailers into request headers or not"),
AP_INIT_ITERATE("HttpProtocolOptions", set_http_protocol_options, NULL, RSRC_CONF,
- "'Allow0.9' or 'Require1.0' (default) to allow or deny HTTP/0.9; "
- "'Unsafe' or 'Strict' (default) to process incorrect requests"),
+ "'Allow0.9' or 'Require1.0' (default); "
+ "'RegisteredMethods' or 'LenientMethods' (default); "
+ "'Unsafe' or 'Strict' (default). Sets HTTP acceptance rules"),
AP_INIT_ITERATE("RegisterHttpMethod", set_http_method, NULL, RSRC_CONF,
"Registers non-standard HTTP methods"),
AP_INIT_FLAG("HttpContentLengthHeadZero", set_cl_head_zero, NULL, OR_OPTIONS,
#define T_ESCAPE_FORENSIC (0x20)
#define T_ESCAPE_URLENCODED (0x40)
#define T_HTTP_CTRLS (0x80)
-#define T_URI_RFC3986 (0x100)
+#define T_VCHAR_OBSTEXT (0x100)
int main(int argc, char *argv[])
{
"#define T_ESCAPE_FORENSIC (%u)\n"
"#define T_ESCAPE_URLENCODED (%u)\n"
"#define T_HTTP_CTRLS (%u)\n"
- "#define T_URI_RFC3986 (%u)\n"
+ "#define T_VCHAR_OBSTEXT (%u)\n"
"\n"
"static const unsigned short test_char_table[256] = {",
T_ESCAPE_SHELL_CMD,
T_ESCAPE_FORENSIC,
T_ESCAPE_URLENCODED,
T_HTTP_CTRLS,
- T_URI_RFC3986);
+ T_VCHAR_OBSTEXT);
for (c = 0; c < 256; ++c) {
flags = 0;
* and unreserved (2.3) that are possible somewhere within a URI.
* Spec requires all others to be %XX encoded, including obs-text.
*/
- if (c && (strchr("%" /* pct-encode */
- ":/?#[]@" /* gen-delims */
- "!$&'()*+,;=" /* sub-delims */
- "-._~", c) || apr_isalnum(c))) { /* unreserved */
- flags |= T_URI_RFC3986;
+ if (c && !apr_iscntrl(c) && c != ' ') {
+ flags |= T_VCHAR_OBSTEXT;
}
/* For logging, escape all control characters,
int num_blank_lines = DEFAULT_LIMIT_BLANK_LINES;
core_server_config *conf = ap_get_core_module_config(r->server->module_config);
int strict = (conf->http_conformance != AP_HTTP_CONFORMANCE_UNSAFE);
- int stricturi = (conf->http_stricturi != AP_HTTP_URI_UNSAFE);
/* Read past empty lines until we get a real request line,
* a read error, the connection closes (EOF), or we timeout.
*/
if (strict) {
ll = (char*) ap_scan_http_token(r->method);
- if (((ll == r->method) || (*ll && !apr_isspace(*ll)))
- && deferred_error == rrl_none) {
- deferred_error = rrl_badmethod;
- ll = strpbrk(ll, "\t\n\v\f\r ");
- }
}
else {
- ll = strpbrk(r->method, "\t\n\v\f\r ");
+ ll = (char*) ap_scan_vchar_obstext(r->method);
+ }
+
+ if (((ll == r->method) || (*ll && !apr_isspace(*ll)))
+ && deferred_error == rrl_none) {
+ deferred_error = rrl_badmethod;
+ ll = strpbrk(ll, "\t\n\v\f\r ");
}
/* Verify method terminated with a single SP, or mark as specific error */
if (!*uri && deferred_error == rrl_none)
deferred_error = rrl_missinguri;
- /* Scan the URI up to the next whitespace, ensure it contains only
- * valid RFC3986 characters, otherwise mark in error
+ /* Scan the URI up to the next whitespace, ensure it contains no raw
+ * control characters, otherwise mark in error
*/
- if (stricturi) {
- ll = (char*) ap_scan_http_uri_safe(uri);
- if (ll == uri || (*ll && !apr_isspace(*ll))) {
- deferred_error = rrl_baduri;
- ll = strpbrk(ll, "\t\n\v\f\r ");
- }
- }
- else {
- ll = strpbrk(uri, "\t\n\v\f\r ");
+ ll = (char*) ap_scan_vchar_obstext(uri);
+ if (ll == uri || (*ll && !apr_isspace(*ll))) {
+ deferred_error = rrl_baduri;
+ ll = strpbrk(ll, "\t\n\v\f\r ");
}
/* Verify method terminated with a single SP, or mark as specific error */
*ll = '\0';
/* Scan the protocol up to the next whitespace, validation comes later */
- if (!(ll = strpbrk(r->protocol, " \t\n\v\f\r"))) {
+ if (!(ll = (char*) ap_scan_vchar_obstext(r->protocol))) {
len = strlen(r->protocol);
goto rrl_done;
}
* determine if trailing text is found, unconditionally mark in error,
* finally NUL terminate the protocol string
*/
- if (strict && *ll) {
+ if (*ll && !apr_isspace(*ll)) {
+ deferred_error = rrl_badprotocol;
+ }
+ else if (strict && *ll) {
deferred_error = rrl_excesswhitespace;
}
else {
}
if (strict) {
- /* No sense re-testing here for what was evaulated above */
- if (!stricturi && ap_has_cntrl(r->the_request)) {
- ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02420)
- "HTTP Request Line; URI must not contain control"
- " characters");
- r->status = HTTP_BAD_REQUEST;
- goto rrl_failed;
- }
if (r->parsed_uri.fragment) {
/* RFC3986 3.5: no fragment */
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02421)
return tok;
}
-/* Scan a string for valid URI characters per RFC3986, and
- * return a pointer to the first non-URI character encountered.
+/* Scan a string for visible ASCII (0x21-0x7E) or obstext (0x80+)
+ * and return a pointer to the first ctrl/space character encountered.
*/
-AP_DECLARE(const char *) ap_scan_http_uri_safe(const char *ptr)
+AP_DECLARE(const char *) ap_scan_vchar_obstext(const char *ptr)
{
- for ( ; TEST_CHAR(*ptr, T_URI_RFC3986); ++ptr) ;
+ for ( ; TEST_CHAR(*ptr, T_VCHAR_OBSTEXT); ++ptr) ;
return ptr;
}
*dest = '\0';
}
-AP_DECLARE(int) ap_has_cntrl(const char *str)
-{
- while (*str) {
- if (apr_iscntrl(*str))
- return 1;
- str++;
- }
- return 0;
-}
-
AP_DECLARE(int) ap_is_directory(apr_pool_t *p, const char *path)
{
apr_finfo_t finfo;
projects / thirdparty / apache / httpd.git / commitdiff
