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gecko-dev/dom/security/nsCSPParser.cpp

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/ArrayUtils.h"
#include "mozilla/Preferences.h"
#include "mozilla/StaticPrefs_security.h"
#include "nsCOMPtr.h"
#include "nsContentUtils.h"
#include "nsCSPParser.h"
#include "nsCSPUtils.h"
#include "nsIScriptError.h"
#include "nsNetUtil.h"
#include "nsReadableUtils.h"
#include "nsServiceManagerUtils.h"
#include "nsUnicharUtils.h"
using namespace mozilla;
static LogModule* GetCspParserLog() {
static LazyLogModule gCspParserPRLog("CSPParser");
return gCspParserPRLog;
}
#define CSPPARSERLOG(args) \
MOZ_LOG(GetCspParserLog(), mozilla::LogLevel::Debug, args)
#define CSPPARSERLOGENABLED() \
MOZ_LOG_TEST(GetCspParserLog(), mozilla::LogLevel::Debug)
// clang-format off
static const char16_t COLON = ':';
static const char16_t SEMICOLON = ';';
static const char16_t SLASH = '/';
static const char16_t PLUS = '+';
static const char16_t DASH = '-';
static const char16_t DOT = '.';
static const char16_t UNDERLINE = '_';
static const char16_t TILDE = '~';
static const char16_t WILDCARD = '*';
static const char16_t SINGLEQUOTE = '\'';
static const char16_t NUMBER_SIGN = '#';
static const char16_t QUESTIONMARK = '?';
static const char16_t PERCENT_SIGN = '%';
static const char16_t EXCLAMATION = '!';
static const char16_t DOLLAR = '$';
static const char16_t AMPERSAND = '&';
static const char16_t OPENBRACE = '(';
static const char16_t CLOSINGBRACE = ')';
static const char16_t EQUALS = '=';
static const char16_t ATSYMBOL = '@';
// clang-format on
static const uint32_t kSubHostPathCharacterCutoff = 512;
static const char* const kHashSourceValidFns[] = {"sha256", "sha384", "sha512"};
static const uint32_t kHashSourceValidFnsLen = 3;
/* ===== nsCSPParser ==================== */
nsCSPParser::nsCSPParser(policyTokens& aTokens, nsIURI* aSelfURI,
nsCSPContext* aCSPContext, bool aDeliveredViaMetaTag)
: mCurChar(nullptr),
mEndChar(nullptr),
mHasHashOrNonce(false),
mStrictDynamic(false),
mUnsafeInlineKeywordSrc(nullptr),
mChildSrc(nullptr),
mFrameSrc(nullptr),
mWorkerSrc(nullptr),
mScriptSrc(nullptr),
mParsingFrameAncestorsDir(false),
mTokens(aTokens.Clone()),
mSelfURI(aSelfURI),
mPolicy(nullptr),
mCSPContext(aCSPContext),
mDeliveredViaMetaTag(aDeliveredViaMetaTag) {
CSPPARSERLOG(("nsCSPParser::nsCSPParser"));
}
nsCSPParser::~nsCSPParser() { CSPPARSERLOG(("nsCSPParser::~nsCSPParser")); }
static bool isCharacterToken(char16_t aSymbol) {
return (aSymbol >= 'a' && aSymbol <= 'z') ||
(aSymbol >= 'A' && aSymbol <= 'Z');
}
static bool isNumberToken(char16_t aSymbol) {
return (aSymbol >= '0' && aSymbol <= '9');
}
static bool isValidHexDig(char16_t aHexDig) {
return (isNumberToken(aHexDig) || (aHexDig >= 'A' && aHexDig <= 'F') ||
(aHexDig >= 'a' && aHexDig <= 'f'));
}
static bool isValidBase64Value(const char16_t* cur, const char16_t* end) {
// Using grammar at
// https://w3c.github.io/webappsec-csp/#grammardef-nonce-source
// May end with one or two =
if (end > cur && *(end - 1) == EQUALS) end--;
if (end > cur && *(end - 1) == EQUALS) end--;
// Must have at least one character aside from any =
if (end == cur) {
return false;
}
// Rest must all be A-Za-z0-9+/-_
for (; cur < end; ++cur) {
if (!(isCharacterToken(*cur) || isNumberToken(*cur) || *cur == PLUS ||
*cur == SLASH || *cur == DASH || *cur == UNDERLINE)) {
return false;
}
}
return true;
}
void nsCSPParser::resetCurChar(const nsAString& aToken) {
mCurChar = aToken.BeginReading();
mEndChar = aToken.EndReading();
resetCurValue();
}
// The path is terminated by the first question mark ("?") or
// number sign ("#") character, or by the end of the URI.
// http://tools.ietf.org/html/rfc3986#section-3.3
bool nsCSPParser::atEndOfPath() {
return (atEnd() || peek(QUESTIONMARK) || peek(NUMBER_SIGN));
}
// unreserved = ALPHA / DIGIT / "-" / "." / "_" / "~"
bool nsCSPParser::atValidUnreservedChar() {
return (peek(isCharacterToken) || peek(isNumberToken) || peek(DASH) ||
peek(DOT) || peek(UNDERLINE) || peek(TILDE));
}
// sub-delims = "!" / "$" / "&" / "'" / "(" / ")"
// / "*" / "+" / "," / ";" / "="
// Please note that even though ',' and ';' appear to be
// valid sub-delims according to the RFC production of paths,
// both can not appear here by itself, they would need to be
// pct-encoded in order to be part of the path.
bool nsCSPParser::atValidSubDelimChar() {
return (peek(EXCLAMATION) || peek(DOLLAR) || peek(AMPERSAND) ||
peek(SINGLEQUOTE) || peek(OPENBRACE) || peek(CLOSINGBRACE) ||
peek(WILDCARD) || peek(PLUS) || peek(EQUALS));
}
// pct-encoded = "%" HEXDIG HEXDIG
bool nsCSPParser::atValidPctEncodedChar() {
const char16_t* pctCurChar = mCurChar;
if ((pctCurChar + 2) >= mEndChar) {
// string too short, can't be a valid pct-encoded char.
return false;
}
// Any valid pct-encoding must follow the following format:
// "% HEXDIG HEXDIG"
if (PERCENT_SIGN != *pctCurChar || !isValidHexDig(*(pctCurChar + 1)) ||
!isValidHexDig(*(pctCurChar + 2))) {
return false;
}
return true;
}
// pchar = unreserved / pct-encoded / sub-delims / ":" / "@"
// http://tools.ietf.org/html/rfc3986#section-3.3
bool nsCSPParser::atValidPathChar() {
return (atValidUnreservedChar() || atValidSubDelimChar() ||
atValidPctEncodedChar() || peek(COLON) || peek(ATSYMBOL));
}
void nsCSPParser::logWarningErrorToConsole(uint32_t aSeverityFlag,
const char* aProperty,
const nsTArray<nsString>& aParams) {
CSPPARSERLOG(("nsCSPParser::logWarningErrorToConsole: %s", aProperty));
// send console messages off to the context and let the context
// deal with it (potentially messages need to be queued up)
mCSPContext->logToConsole(aProperty, aParams,
EmptyString(), // aSourceName
EmptyString(), // aSourceLine
0, // aLineNumber
0, // aColumnNumber
aSeverityFlag); // aFlags
}
bool nsCSPParser::hostChar() {
if (atEnd()) {
return false;
}
return accept(isCharacterToken) || accept(isNumberToken) || accept(DASH);
}
// (ALPHA / DIGIT / "+" / "-" / "." )
bool nsCSPParser::schemeChar() {
if (atEnd()) {
return false;
}
return accept(isCharacterToken) || accept(isNumberToken) || accept(PLUS) ||
accept(DASH) || accept(DOT);
}
// port = ":" ( 1*DIGIT / "*" )
bool nsCSPParser::port() {
CSPPARSERLOG(("nsCSPParser::port, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Consume the COLON we just peeked at in houstSource
accept(COLON);
// Resetting current value since we start to parse a port now.
// e.g; "http://www.example.com:8888" then we have already parsed
// everything up to (including) ":";
resetCurValue();
// Port might be "*"
if (accept(WILDCARD)) {
return true;
}
// Port must start with a number
if (!accept(isNumberToken)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParsePort",
params);
return false;
}
// Consume more numbers and set parsed port to the nsCSPHost
while (accept(isNumberToken)) { /* consume */
}
return true;
}
bool nsCSPParser::subPath(nsCSPHostSrc* aCspHost) {
CSPPARSERLOG(("nsCSPParser::subPath, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Emergency exit to avoid endless loops in case a path in a CSP policy
// is longer than 512 characters, or also to avoid endless loops
// in case we are parsing unrecognized characters in the following loop.
uint32_t charCounter = 0;
nsString pctDecodedSubPath;
while (!atEndOfPath()) {
if (peek(SLASH)) {
// before appendig any additional portion of a subpath we have to
// pct-decode that portion of the subpath. atValidPathChar() already
// verified a correct pct-encoding, now we can safely decode and append
// the decoded-sub path.
CSP_PercentDecodeStr(mCurValue, pctDecodedSubPath);
aCspHost->appendPath(pctDecodedSubPath);
// Resetting current value since we are appending parts of the path
// to aCspHost, e.g; "http://www.example.com/path1/path2" then the
// first part is "/path1", second part "/path2"
resetCurValue();
} else if (!atValidPathChar()) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldntParseInvalidSource", params);
return false;
}
// potentially we have encountred a valid pct-encoded character in
// atValidPathChar(); if so, we have to account for "% HEXDIG HEXDIG" and
// advance the pointer past the pct-encoded char.
if (peek(PERCENT_SIGN)) {
advance();
advance();
}
advance();
if (++charCounter > kSubHostPathCharacterCutoff) {
return false;
}
}
// before appendig any additional portion of a subpath we have to pct-decode
// that portion of the subpath. atValidPathChar() already verified a correct
// pct-encoding, now we can safely decode and append the decoded-sub path.
CSP_PercentDecodeStr(mCurValue, pctDecodedSubPath);
aCspHost->appendPath(pctDecodedSubPath);
resetCurValue();
return true;
}
bool nsCSPParser::path(nsCSPHostSrc* aCspHost) {
CSPPARSERLOG(("nsCSPParser::path, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Resetting current value and forgetting everything we have parsed so far
// e.g. parsing "http://www.example.com/path1/path2", then
// "http://www.example.com" has already been parsed so far
// forget about it.
resetCurValue();
if (!accept(SLASH)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldntParseInvalidSource", params);
return false;
}
if (atEndOfPath()) {
// one slash right after host [port] is also considered a path, e.g.
// www.example.com/ should result in www.example.com/
// please note that we do not have to perform any pct-decoding here
// because we are just appending a '/' and not any actual chars.
aCspHost->appendPath(u"/"_ns);
return true;
}
// path can begin with "/" but not "//"
// see http://tools.ietf.org/html/rfc3986#section-3.3
if (peek(SLASH)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldntParseInvalidSource", params);
return false;
}
return subPath(aCspHost);
}
bool nsCSPParser::subHost() {
CSPPARSERLOG(("nsCSPParser::subHost, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Emergency exit to avoid endless loops in case a host in a CSP policy
// is longer than 512 characters, or also to avoid endless loops
// in case we are parsing unrecognized characters in the following loop.
uint32_t charCounter = 0;
while (!atEndOfPath() && !peek(COLON) && !peek(SLASH)) {
++charCounter;
while (hostChar()) {
/* consume */
++charCounter;
}
if (accept(DOT) && !hostChar()) {
return false;
}
if (charCounter > kSubHostPathCharacterCutoff) {
return false;
}
}
return true;
}
// host = "*" / [ "*." ] 1*host-char *( "." 1*host-char )
nsCSPHostSrc* nsCSPParser::host() {
CSPPARSERLOG(("nsCSPParser::host, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Check if the token starts with "*"; please remember that we handle
// a single "*" as host in sourceExpression, but we still have to handle
// the case where a scheme was defined, e.g., as:
// "https://*", "*.example.com", "*:*", etc.
if (accept(WILDCARD)) {
// Might solely be the wildcard
if (atEnd() || peek(COLON)) {
return new nsCSPHostSrc(mCurValue);
}
// If the token is not only the "*", a "." must follow right after
if (!accept(DOT)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldntParseInvalidHost", params);
return nullptr;
}
}
// Expecting at least one host-char
if (!hostChar()) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldntParseInvalidHost", params);
return nullptr;
}
// There might be several sub hosts defined.
if (!subHost()) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldntParseInvalidHost", params);
return nullptr;
}
// HostName might match a keyword, log to the console.
if (CSP_IsQuotelessKeyword(mCurValue)) {
nsString keyword = mCurValue;
ToLowerCase(keyword);
AutoTArray<nsString, 2> params = {mCurToken, keyword};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"hostNameMightBeKeyword", params);
}
// Create a new nsCSPHostSrc with the parsed host.
return new nsCSPHostSrc(mCurValue);
}
// keyword-source = "'self'" / "'unsafe-inline'" / "'unsafe-eval'"
nsCSPBaseSrc* nsCSPParser::keywordSource() {
CSPPARSERLOG(("nsCSPParser::keywordSource, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Special case handling for 'self' which is not stored internally as a
// keyword, but rather creates a nsCSPHostSrc using the selfURI
if (CSP_IsKeyword(mCurToken, CSP_SELF)) {
return CSP_CreateHostSrcFromSelfURI(mSelfURI);
}
if (CSP_IsKeyword(mCurToken, CSP_REPORT_SAMPLE)) {
return new nsCSPKeywordSrc(CSP_UTF16KeywordToEnum(mCurToken));
}
if (CSP_IsKeyword(mCurToken, CSP_STRICT_DYNAMIC)) {
// make sure strict dynamic is enabled
if (!StaticPrefs::security_csp_enableStrictDynamic()) {
return nullptr;
}
if (!CSP_IsDirective(mCurDir[0],
nsIContentSecurityPolicy::SCRIPT_SRC_DIRECTIVE)) {
// Todo: Enforce 'strict-dynamic' within default-src; see Bug 1313937
AutoTArray<nsString, 1> params = {u"strict-dynamic"_ns};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoringStrictDynamic", params);
return nullptr;
}
mStrictDynamic = true;
return new nsCSPKeywordSrc(CSP_UTF16KeywordToEnum(mCurToken));
}
if (CSP_IsKeyword(mCurToken, CSP_UNSAFE_INLINE)) {
nsWeakPtr ctx = mCSPContext->GetLoadingContext();
nsCOMPtr<Document> doc = do_QueryReferent(ctx);
if (doc) {
doc->SetHasUnsafeInlineCSP(true);
}
// make sure script-src only contains 'unsafe-inline' once;
// ignore duplicates and log warning
if (mUnsafeInlineKeywordSrc) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoringDuplicateSrc", params);
return nullptr;
}
// cache if we encounter 'unsafe-inline' so we can invalidate (ignore) it in
// case that script-src directive also contains hash- or nonce-.
mUnsafeInlineKeywordSrc =
new nsCSPKeywordSrc(CSP_UTF16KeywordToEnum(mCurToken));
return mUnsafeInlineKeywordSrc;
}
if (CSP_IsKeyword(mCurToken, CSP_UNSAFE_EVAL)) {
nsWeakPtr ctx = mCSPContext->GetLoadingContext();
nsCOMPtr<Document> doc = do_QueryReferent(ctx);
if (doc) {
doc->SetHasUnsafeEvalCSP(true);
}
return new nsCSPKeywordSrc(CSP_UTF16KeywordToEnum(mCurToken));
}
if (CSP_IsKeyword(mCurToken, CSP_UNSAFE_ALLOW_REDIRECTS)) {
if (!CSP_IsDirective(mCurDir[0],
nsIContentSecurityPolicy::NAVIGATE_TO_DIRECTIVE)) {
// Only allow 'unsafe-allow-redirects' within navigate-to.
AutoTArray<nsString, 2> params = {u"unsafe-allow-redirects"_ns,
u"navigate-to"_ns};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"IgnoringSourceWithinDirective", params);
return nullptr;
}
return new nsCSPKeywordSrc(CSP_UTF16KeywordToEnum(mCurToken));
}
return nullptr;
}
// host-source = [ scheme "://" ] host [ port ] [ path ]
nsCSPHostSrc* nsCSPParser::hostSource() {
CSPPARSERLOG(("nsCSPParser::hostSource, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
nsCSPHostSrc* cspHost = host();
if (!cspHost) {
// Error was reported in host()
return nullptr;
}
// Calling port() to see if there is a port to parse, if an error
// occurs, port() reports the error, if port() returns true;
// we have a valid port, so we add it to cspHost.
if (peek(COLON)) {
if (!port()) {
delete cspHost;
return nullptr;
}
cspHost->setPort(mCurValue);
}
if (atEndOfPath()) {
return cspHost;
}
// Calling path() to see if there is a path to parse, if an error
// occurs, path() reports the error; handing cspHost as an argument
// which simplifies parsing of several paths.
if (!path(cspHost)) {
// If the host [port] is followed by a path, it has to be a valid path,
// otherwise we pass the nullptr, indicating an error, up the callstack.
// see also http://www.w3.org/TR/CSP11/#source-list
delete cspHost;
return nullptr;
}
return cspHost;
}
// scheme-source = scheme ":"
nsCSPSchemeSrc* nsCSPParser::schemeSource() {
CSPPARSERLOG(("nsCSPParser::schemeSource, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
if (!accept(isCharacterToken)) {
return nullptr;
}
while (schemeChar()) { /* consume */
}
nsString scheme = mCurValue;
// If the potential scheme is not followed by ":" - it's not a scheme
if (!accept(COLON)) {
return nullptr;
}
// If the chraracter following the ":" is a number or the "*"
// then we are not parsing a scheme; but rather a host;
if (peek(isNumberToken) || peek(WILDCARD)) {
return nullptr;
}
return new nsCSPSchemeSrc(scheme);
}
// nonce-source = "'nonce-" nonce-value "'"
nsCSPNonceSrc* nsCSPParser::nonceSource() {
CSPPARSERLOG(("nsCSPParser::nonceSource, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Check if mCurToken begins with "'nonce-" and ends with "'"
if (!StringBeginsWith(mCurToken,
nsDependentString(CSP_EnumToUTF16Keyword(CSP_NONCE)),
nsASCIICaseInsensitiveStringComparator) ||
mCurToken.Last() != SINGLEQUOTE) {
return nullptr;
}
// Trim surrounding single quotes
const nsAString& expr = Substring(mCurToken, 1, mCurToken.Length() - 2);
int32_t dashIndex = expr.FindChar(DASH);
if (dashIndex < 0) {
return nullptr;
}
if (!isValidBase64Value(expr.BeginReading() + dashIndex + 1,
expr.EndReading())) {
return nullptr;
}
// cache if encountering hash or nonce to invalidate unsafe-inline
mHasHashOrNonce = true;
return new nsCSPNonceSrc(
Substring(expr, dashIndex + 1, expr.Length() - dashIndex + 1));
}
// hash-source = "'" hash-algo "-" base64-value "'"
nsCSPHashSrc* nsCSPParser::hashSource() {
CSPPARSERLOG(("nsCSPParser::hashSource, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Check if mCurToken starts and ends with "'"
if (mCurToken.First() != SINGLEQUOTE || mCurToken.Last() != SINGLEQUOTE) {
return nullptr;
}
// Trim surrounding single quotes
const nsAString& expr = Substring(mCurToken, 1, mCurToken.Length() - 2);
int32_t dashIndex = expr.FindChar(DASH);
if (dashIndex < 0) {
return nullptr;
}
if (!isValidBase64Value(expr.BeginReading() + dashIndex + 1,
expr.EndReading())) {
return nullptr;
}
nsAutoString algo(Substring(expr, 0, dashIndex));
nsAutoString hash(
Substring(expr, dashIndex + 1, expr.Length() - dashIndex + 1));
for (uint32_t i = 0; i < kHashSourceValidFnsLen; i++) {
if (algo.LowerCaseEqualsASCII(kHashSourceValidFns[i])) {
// cache if encountering hash or nonce to invalidate unsafe-inline
mHasHashOrNonce = true;
return new nsCSPHashSrc(algo, hash);
}
}
return nullptr;
}
// source-expression = scheme-source / host-source / keyword-source
// / nonce-source / hash-source
nsCSPBaseSrc* nsCSPParser::sourceExpression() {
CSPPARSERLOG(("nsCSPParser::sourceExpression, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Check if it is a keyword
if (nsCSPBaseSrc* cspKeyword = keywordSource()) {
return cspKeyword;
}
// Check if it is a nonce-source
if (nsCSPNonceSrc* cspNonce = nonceSource()) {
return cspNonce;
}
// Check if it is a hash-source
if (nsCSPHashSrc* cspHash = hashSource()) {
return cspHash;
}
// We handle a single "*" as host here, to avoid any confusion when applying
// the default scheme. However, we still would need to apply the default
// scheme in case we would parse "*:80".
if (mCurToken.EqualsASCII("*")) {
return new nsCSPHostSrc(u"*"_ns);
}
// Calling resetCurChar allows us to use mCurChar and mEndChar
// to parse mCurToken; e.g. mCurToken = "http://www.example.com", then
// mCurChar = 'h'
// mEndChar = points just after the last 'm'
// mCurValue = ""
resetCurChar(mCurToken);
// Check if mCurToken starts with a scheme
nsAutoString parsedScheme;
if (nsCSPSchemeSrc* cspScheme = schemeSource()) {
// mCurToken might only enforce a specific scheme
if (atEnd()) {
return cspScheme;
}
// If something follows the scheme, we do not create
// a nsCSPSchemeSrc, but rather a nsCSPHostSrc, which
// needs to know the scheme to enforce; remember the
// scheme and delete cspScheme;
cspScheme->toString(parsedScheme);
parsedScheme.Trim(":", false, true);
delete cspScheme;
// If mCurToken provides not only a scheme, but also a host, we have to
// check if two slashes follow the scheme.
if (!accept(SLASH) || !accept(SLASH)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"failedToParseUnrecognizedSource", params);
return nullptr;
}
}
// Calling resetCurValue allows us to keep pointers for mCurChar and mEndChar
// alive, but resets mCurValue; e.g. mCurToken = "http://www.example.com",
// then mCurChar = 'w' mEndChar = 'm' mCurValue = ""
resetCurValue();
// If mCurToken does not provide a scheme (scheme-less source), we apply the
// scheme from selfURI
if (parsedScheme.IsEmpty()) {
// Resetting internal helpers, because we might already have parsed some of
// the host when trying to parse a scheme.
resetCurChar(mCurToken);
nsAutoCString selfScheme;
mSelfURI->GetScheme(selfScheme);
parsedScheme.AssignASCII(selfScheme.get());
}
// At this point we are expecting a host to be parsed.
// Trying to create a new nsCSPHost.
if (nsCSPHostSrc* cspHost = hostSource()) {
// Do not forget to set the parsed scheme.
cspHost->setScheme(parsedScheme);
cspHost->setWithinFrameAncestorsDir(mParsingFrameAncestorsDir);
return cspHost;
}
// Error was reported in hostSource()
return nullptr;
}
// source-list = *WSP [ source-expression *( 1*WSP source-expression ) *WSP ]
// / *WSP "'none'" *WSP
void nsCSPParser::sourceList(nsTArray<nsCSPBaseSrc*>& outSrcs) {
bool isNone = false;
// remember, srcs start at index 1
for (uint32_t i = 1; i < mCurDir.Length(); i++) {
// mCurToken is only set here and remains the current token
// to be processed, which avoid passing arguments between functions.
mCurToken = mCurDir[i];
resetCurValue();
CSPPARSERLOG(("nsCSPParser::sourceList, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Special case handling for none:
// Ignore 'none' if any other src is available.
// (See http://www.w3.org/TR/CSP11/#parsing)
if (CSP_IsKeyword(mCurToken, CSP_NONE)) {
isNone = true;
continue;
}
// Must be a regular source expression
nsCSPBaseSrc* src = sourceExpression();
if (src) {
outSrcs.AppendElement(src);
}
}
// Check if the directive contains a 'none'
if (isNone) {
// If the directive contains no other srcs, then we set the 'none'
if (outSrcs.IsEmpty() ||
(outSrcs.Length() == 1 && outSrcs[0]->isReportSample())) {
nsCSPKeywordSrc* keyword = new nsCSPKeywordSrc(CSP_NONE);
outSrcs.InsertElementAt(0, keyword);
}
// Otherwise, we ignore 'none' and report a warning
else {
AutoTArray<nsString, 1> params;
params.AppendElement(CSP_EnumToUTF16Keyword(CSP_NONE));
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoringUnknownOption", params);
}
}
}
void nsCSPParser::reportURIList(nsCSPDirective* aDir) {
CSPPARSERLOG(("nsCSPParser::reportURIList"));
nsTArray<nsCSPBaseSrc*> srcs;
nsCOMPtr<nsIURI> uri;
nsresult rv;
// remember, srcs start at index 1
for (uint32_t i = 1; i < mCurDir.Length(); i++) {
mCurToken = mCurDir[i];
CSPPARSERLOG(("nsCSPParser::reportURIList, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
rv = NS_NewURI(getter_AddRefs(uri), mCurToken, "", mSelfURI);
// If creating the URI casued an error, skip this URI
if (NS_FAILED(rv)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldNotParseReportURI", params);
continue;
}
// Create new nsCSPReportURI and append to the list.
nsCSPReportURI* reportURI = new nsCSPReportURI(uri);
srcs.AppendElement(reportURI);
}
if (srcs.Length() == 0) {
AutoTArray<nsString, 1> directiveName = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoringDirectiveWithNoValues", directiveName);
delete aDir;
return;
}
aDir->addSrcs(srcs);
mPolicy->addDirective(aDir);
}
/* Helper function for parsing sandbox flags. This function solely concatenates
* all the source list tokens (the sandbox flags) so the attribute parser
* (nsContentUtils::ParseSandboxAttributeToFlags) can parse them.
*/
void nsCSPParser::sandboxFlagList(nsCSPDirective* aDir) {
CSPPARSERLOG(("nsCSPParser::sandboxFlagList"));
nsAutoString flags;
// remember, srcs start at index 1
for (uint32_t i = 1; i < mCurDir.Length(); i++) {
mCurToken = mCurDir[i];
CSPPARSERLOG(("nsCSPParser::sandboxFlagList, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
if (!nsContentUtils::IsValidSandboxFlag(mCurToken)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldntParseInvalidSandboxFlag", params);
continue;
}
flags.Append(mCurToken);
if (i != mCurDir.Length() - 1) {
flags.AppendLiteral(" ");
}
}
// Please note that the sandbox directive can exist
// by itself (not containing any flags).
nsTArray<nsCSPBaseSrc*> srcs;
srcs.AppendElement(new nsCSPSandboxFlags(flags));
aDir->addSrcs(srcs);
mPolicy->addDirective(aDir);
}
// directive-value = *( WSP / <VCHAR except ";" and ","> )
void nsCSPParser::directiveValue(nsTArray<nsCSPBaseSrc*>& outSrcs) {
CSPPARSERLOG(("nsCSPParser::directiveValue"));
// Just forward to sourceList
sourceList(outSrcs);
}
// directive-name = 1*( ALPHA / DIGIT / "-" )
nsCSPDirective* nsCSPParser::directiveName() {
CSPPARSERLOG(("nsCSPParser::directiveName, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Check if it is a valid directive
if (!CSP_IsValidDirective(mCurToken)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldNotProcessUnknownDirective", params);
return nullptr;
}
// The directive 'reflected-xss' is part of CSP 1.1, see:
// http://www.w3.org/TR/2014/WD-CSP11-20140211/#reflected-xss
// Currently we are not supporting that directive, hence we log a
// warning to the console and ignore the directive including its values.
if (CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::REFLECTED_XSS_DIRECTIVE)) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"notSupportingDirective", params);
return nullptr;
}
// Bug 1529068: Implement navigate-to directive.
// Once all corner cases are resolved we can remove that special
// if-handling here and let the parser just fall through to
// return new nsCSPDirective.
if (CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::NAVIGATE_TO_DIRECTIVE) &&
!StaticPrefs::security_csp_enableNavigateTo()) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"couldNotProcessUnknownDirective", params);
return nullptr;
}
// Make sure the directive does not already exist
// (see http://www.w3.org/TR/CSP11/#parsing)
if (mPolicy->hasDirective(CSP_StringToCSPDirective(mCurToken))) {
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag, "duplicateDirective",
params);
return nullptr;
}
// CSP delivered via meta tag should ignore the following directives:
// report-uri, frame-ancestors, and sandbox, see:
// http://www.w3.org/TR/CSP11/#delivery-html-meta-element
if (mDeliveredViaMetaTag &&
((CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::REPORT_URI_DIRECTIVE)) ||
(CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::FRAME_ANCESTORS_DIRECTIVE)) ||
(CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::SANDBOX_DIRECTIVE)))) {
// log to the console to indicate that meta CSP is ignoring the directive
AutoTArray<nsString, 1> params = {mCurToken};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoringSrcFromMetaCSP", params);
return nullptr;
}
// special case handling for block-all-mixed-content
if (CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::BLOCK_ALL_MIXED_CONTENT)) {
return new nsBlockAllMixedContentDirective(
CSP_StringToCSPDirective(mCurToken));
}
// special case handling for upgrade-insecure-requests
if (CSP_IsDirective(
mCurToken, nsIContentSecurityPolicy::UPGRADE_IF_INSECURE_DIRECTIVE)) {
return new nsUpgradeInsecureDirective(CSP_StringToCSPDirective(mCurToken));
}
// if we have a child-src, cache it as a fallback for
// * workers (if worker-src is not explicitly specified)
// * frames (if frame-src is not explicitly specified)
if (CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::CHILD_SRC_DIRECTIVE)) {
mChildSrc = new nsCSPChildSrcDirective(CSP_StringToCSPDirective(mCurToken));
return mChildSrc;
}
// if we have a frame-src, cache it so we can discard child-src for frames
if (CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::FRAME_SRC_DIRECTIVE)) {
mFrameSrc = new nsCSPDirective(CSP_StringToCSPDirective(mCurToken));
return mFrameSrc;
}
// if we have a worker-src, cache it so we can discard child-src for workers
if (CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::WORKER_SRC_DIRECTIVE)) {
mWorkerSrc = new nsCSPDirective(CSP_StringToCSPDirective(mCurToken));
return mWorkerSrc;
}
// if we have a script-src, cache it as a fallback for worker-src
// in case child-src is not present
if (CSP_IsDirective(mCurToken,
nsIContentSecurityPolicy::SCRIPT_SRC_DIRECTIVE)) {
mScriptSrc =
new nsCSPScriptSrcDirective(CSP_StringToCSPDirective(mCurToken));
return mScriptSrc;
}
return new nsCSPDirective(CSP_StringToCSPDirective(mCurToken));
}
// directive = *WSP [ directive-name [ WSP directive-value ] ]
void nsCSPParser::directive() {
// Set the directiveName to mCurToken
// Remember, the directive name is stored at index 0
mCurToken = mCurDir[0];
CSPPARSERLOG(("nsCSPParser::directive, mCurToken: %s, mCurValue: %s",
NS_ConvertUTF16toUTF8(mCurToken).get(),
NS_ConvertUTF16toUTF8(mCurValue).get()));
// Make sure that the directive-srcs-array contains at least
// one directive and one src.
if (mCurDir.Length() < 1) {
AutoTArray<nsString, 1> params = {u"directive missing"_ns};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"failedToParseUnrecognizedSource", params);
return;
}
if (CSP_IsEmptyDirective(mCurValue, mCurToken)) {
return;
}
// Try to create a new CSPDirective
nsCSPDirective* cspDir = directiveName();
if (!cspDir) {
// if we can not create a CSPDirective, we can skip parsing the srcs for
// that array
return;
}
// special case handling for block-all-mixed-content, which is only specified
// by a directive name but does not include any srcs.
if (cspDir->equals(nsIContentSecurityPolicy::BLOCK_ALL_MIXED_CONTENT)) {
if (mCurDir.Length() > 1) {
AutoTArray<nsString, 1> params = {u"block-all-mixed-content"_ns};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoreSrcForDirective", params);
}
// add the directive and return
mPolicy->addDirective(cspDir);
return;
}
// special case handling for upgrade-insecure-requests, which is only
// specified by a directive name but does not include any srcs.
if (cspDir->equals(nsIContentSecurityPolicy::UPGRADE_IF_INSECURE_DIRECTIVE)) {
if (mCurDir.Length() > 1) {
AutoTArray<nsString, 1> params = {u"upgrade-insecure-requests"_ns};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoreSrcForDirective", params);
}
// add the directive and return
mPolicy->addUpgradeInsecDir(
static_cast<nsUpgradeInsecureDirective*>(cspDir));
return;
}
// special case handling for report-uri directive (since it doesn't contain
// a valid source list but rather actual URIs)
if (CSP_IsDirective(mCurDir[0],
nsIContentSecurityPolicy::REPORT_URI_DIRECTIVE)) {
reportURIList(cspDir);
return;
}
// special case handling for sandbox directive (since it doe4sn't contain
// a valid source list but rather special sandbox flags)
if (CSP_IsDirective(mCurDir[0],
nsIContentSecurityPolicy::SANDBOX_DIRECTIVE)) {
sandboxFlagList(cspDir);
return;
}
// make sure to reset cache variables when trying to invalidate unsafe-inline;
// unsafe-inline might not only appear in script-src, but also in default-src
mHasHashOrNonce = false;
mStrictDynamic = false;
mUnsafeInlineKeywordSrc = nullptr;
mParsingFrameAncestorsDir = CSP_IsDirective(
mCurDir[0], nsIContentSecurityPolicy::FRAME_ANCESTORS_DIRECTIVE);
// Try to parse all the srcs by handing the array off to directiveValue
nsTArray<nsCSPBaseSrc*> srcs;
directiveValue(srcs);
// If we can not parse any srcs; we let the source expression be the empty set
// ('none') see, http://www.w3.org/TR/CSP11/#source-list-parsing
if (srcs.IsEmpty() || (srcs.Length() == 1 && srcs[0]->isReportSample())) {
nsCSPKeywordSrc* keyword = new nsCSPKeywordSrc(CSP_NONE);
srcs.InsertElementAt(0, keyword);
}
// If policy contains 'strict-dynamic' invalidate all srcs within script-src.
if (mStrictDynamic) {
MOZ_ASSERT(cspDir->equals(nsIContentSecurityPolicy::SCRIPT_SRC_DIRECTIVE),
"strict-dynamic only allowed within script-src");
for (uint32_t i = 0; i < srcs.Length(); i++) {
// Please note that nsCSPNonceSrc as well as nsCSPHashSrc overwrite
// invalidate(), so it's fine to just call invalidate() on all srcs.
// Please also note that nsCSPKeywordSrc() can not be invalidated and
// always returns false unless the keyword is 'strict-dynamic' in which
// case we allow the load if the script is not parser created!
srcs[i]->invalidate();
// Log a message to the console that src will be ignored.
nsAutoString srcStr;
srcs[i]->toString(srcStr);
// Even though we invalidate all of the srcs internally, we don't want to
// log messages for the srcs: (1) strict-dynamic, (2) unsafe-inline, (3)
// nonces, and (4) hashes
if (!srcStr.EqualsASCII(CSP_EnumToUTF8Keyword(CSP_STRICT_DYNAMIC)) &&
!srcStr.EqualsASCII(CSP_EnumToUTF8Keyword(CSP_UNSAFE_EVAL)) &&
!StringBeginsWith(
srcStr, nsDependentString(CSP_EnumToUTF16Keyword(CSP_NONCE))) &&
!StringBeginsWith(srcStr, u"'sha"_ns)) {
AutoTArray<nsString, 1> params = {srcStr};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoringSrcForStrictDynamic", params);
}
}
// Log a warning that all scripts might be blocked because the policy
// contains 'strict-dynamic' but no valid nonce or hash.
if (!mHasHashOrNonce) {
AutoTArray<nsString, 1> params = {mCurDir[0]};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"strictDynamicButNoHashOrNonce", params);
}
} else if (mHasHashOrNonce && mUnsafeInlineKeywordSrc &&
(cspDir->equals(nsIContentSecurityPolicy::SCRIPT_SRC_DIRECTIVE) ||
cspDir->equals(nsIContentSecurityPolicy::STYLE_SRC_DIRECTIVE))) {
mUnsafeInlineKeywordSrc->invalidate();
// log to the console that unsafe-inline will be ignored
AutoTArray<nsString, 1> params = {u"'unsafe-inline'"_ns};
logWarningErrorToConsole(nsIScriptError::warningFlag,
"ignoringSrcWithinScriptStyleSrc", params);
}
// Add the newly created srcs to the directive and add the directive to the
// policy
cspDir->addSrcs(srcs);
mPolicy->addDirective(cspDir);
}
// policy = [ directive *( ";" [ directive ] ) ]
nsCSPPolicy* nsCSPParser::policy() {
CSPPARSERLOG(("nsCSPParser::policy"));
mPolicy = new nsCSPPolicy();
for (uint32_t i = 0; i < mTokens.Length(); i++) {
// All input is already tokenized; set one tokenized array in the form of
// [ name, src, src, ... ]
// to mCurDir and call directive which processes the current directive.
mCurDir = mTokens[i].Clone();
directive();
}
if (mChildSrc) {
if (!mFrameSrc) {
// if frame-src is specified explicitly for that policy than child-src
// should not restrict frames; if not, than child-src needs to restrict
// frames.
mChildSrc->setRestrictFrames();
}
if (!mWorkerSrc) {
// if worker-src is specified explicitly for that policy than child-src
// should not restrict workers; if not, than child-src needs to restrict
// workers.
mChildSrc->setRestrictWorkers();
}
}
// if script-src is specified, but not worker-src and also no child-src, then
// script-src has to govern workers.
if (mScriptSrc && !mWorkerSrc && !mChildSrc) {
mScriptSrc->setRestrictWorkers();
}
return mPolicy;
}
nsCSPPolicy* nsCSPParser::parseContentSecurityPolicy(
const nsAString& aPolicyString, nsIURI* aSelfURI, bool aReportOnly,
nsCSPContext* aCSPContext, bool aDeliveredViaMetaTag) {
if (CSPPARSERLOGENABLED()) {
CSPPARSERLOG(("nsCSPParser::parseContentSecurityPolicy, policy: %s",
NS_ConvertUTF16toUTF8(aPolicyString).get()));
CSPPARSERLOG(("nsCSPParser::parseContentSecurityPolicy, selfURI: %s",
aSelfURI->GetSpecOrDefault().get()));
CSPPARSERLOG(("nsCSPParser::parseContentSecurityPolicy, reportOnly: %s",
(aReportOnly ? "true" : "false")));
CSPPARSERLOG(
("nsCSPParser::parseContentSecurityPolicy, deliveredViaMetaTag: %s",
(aDeliveredViaMetaTag ? "true" : "false")));
}
NS_ASSERTION(aSelfURI, "Can not parseContentSecurityPolicy without aSelfURI");
// Separate all input into tokens and store them in the form of:
// [ [ name, src, src, ... ], [ name, src, src, ... ], ... ]
// The tokenizer itself can not fail; all eventual errors
// are detected in the parser itself.
nsTArray<CopyableTArray<nsString> > tokens;
PolicyTokenizer::tokenizePolicy(aPolicyString, tokens);
nsCSPParser parser(tokens, aSelfURI, aCSPContext, aDeliveredViaMetaTag);
// Start the parser to generate a new CSPPolicy using the generated tokens.
nsCSPPolicy* policy = parser.policy();
// Check that report-only policies define a report-uri, otherwise log warning.
if (aReportOnly) {
policy->setReportOnlyFlag(true);
if (!policy->hasDirective(nsIContentSecurityPolicy::REPORT_URI_DIRECTIVE)) {
nsAutoCString prePath;
nsresult rv = aSelfURI->GetPrePath(prePath);
NS_ENSURE_SUCCESS(rv, policy);
AutoTArray<nsString, 1> params;
CopyUTF8toUTF16(prePath, *params.AppendElement());
parser.logWarningErrorToConsole(nsIScriptError::warningFlag,
"reportURInotInReportOnlyHeader", params);
}
}
policy->setDeliveredViaMetaTagFlag(aDeliveredViaMetaTag);
if (policy->getNumDirectives() == 0) {
// Individual errors were already reported in the parser, but if
// we do not have an enforcable directive at all, we return null.
delete policy;
return nullptr;
}
if (CSPPARSERLOGENABLED()) {
nsString parsedPolicy;
policy->toString(parsedPolicy);
CSPPARSERLOG(("nsCSPParser::parseContentSecurityPolicy, parsedPolicy: %s",
NS_ConvertUTF16toUTF8(parsedPolicy).get()));
}
return policy;
}
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