/* -*- 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 "nsCOMPtr.h" #include "nsContentUtils.h" #include "nsCSPParser.h" #include "nsCSPUtils.h" #include "nsIConsoleService.h" #include "nsIContentPolicy.h" #include "nsIScriptError.h" #include "nsIStringBundle.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) 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 = '@'; static const uint32_t kSubHostPathCharacterCutoff = 512; static const char *const kHashSourceValidFns [] = { "sha256", "sha384", "sha512" }; static const uint32_t kHashSourceValidFnsLen = 3; static const char* const kStyle = "style"; static const char* const kScript = "script"; /* ===== nsCSPParser ==================== */ bool nsCSPParser::sCSPExperimentalEnabled = false; bool nsCSPParser::sStrictDynamicEnabled = false; 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) , mSelfURI(aSelfURI) , mPolicy(nullptr) , mCSPContext(aCSPContext) , mDeliveredViaMetaTag(aDeliveredViaMetaTag) { static bool initialized = false; if (!initialized) { initialized = true; Preferences::AddBoolVarCache(&sCSPExperimentalEnabled, "security.csp.experimentalEnabled"); Preferences::AddBoolVarCache(&sStrictDynamicEnabled, "security.csp.enableStrictDynamic"); } 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 char16_t* aParams[], uint32_t aParamsLength) { 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, aParamsLength, 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)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParsePort", params, ArrayLength(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()) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParseInvalidSource", params, ArrayLength(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)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParseInvalidSource", params, ArrayLength(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(NS_LITERAL_STRING("/")); return true; } // path can begin with "/" but not "//" // see http://tools.ietf.org/html/rfc3986#section-3.3 if (peek(SLASH)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParseInvalidSource", params, ArrayLength(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)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParseInvalidHost", params, ArrayLength(params)); return nullptr; } } // Expecting at least one host-char if (!hostChar()) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParseInvalidHost", params, ArrayLength(params)); return nullptr; } // There might be several sub hosts defined. if (!subHost()) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParseInvalidHost", params, ArrayLength(params)); return nullptr; } // HostName might match a keyword, log to the console. if (CSP_IsQuotelessKeyword(mCurValue)) { nsString keyword = mCurValue; ToLowerCase(keyword); const char16_t* params[] = { mCurToken.get(), keyword.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "hostNameMightBeKeyword", params, ArrayLength(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_STRICT_DYNAMIC)) { // make sure strict dynamic is enabled if (!sStrictDynamicEnabled) { return nullptr; } if (!CSP_IsDirective(mCurDir[0], nsIContentSecurityPolicy::SCRIPT_SRC_DIRECTIVE)) { // Todo: Enforce 'strict-dynamic' within default-src; see Bug 1313937 const char16_t* params[] = { u"strict-dynamic" }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoringStrictDynamic", params, ArrayLength(params)); return nullptr; } mStrictDynamic = true; return new nsCSPKeywordSrc(CSP_UTF16KeywordToEnum(mCurToken)); } if (CSP_IsKeyword(mCurToken, CSP_UNSAFE_INLINE)) { nsWeakPtr ctx = mCSPContext->GetLoadingContext(); nsCOMPtr 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) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoringDuplicateSrc", params, ArrayLength(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 doc = do_QueryReferent(ctx); if (doc) { doc->SetHasUnsafeEvalCSP(true); } 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(NS_LITERAL_STRING("*")); } // 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)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "failedToParseUnrecognizedSource", params, ArrayLength(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& 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.Length() == 0) { nsCSPKeywordSrc *keyword = new nsCSPKeywordSrc(CSP_NONE); outSrcs.AppendElement(keyword); } // Otherwise, we ignore 'none' and report a warning else { const char16_t* params[] = { CSP_EnumToUTF16Keyword(CSP_NONE) }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoringUnknownOption", params, ArrayLength(params)); } } } void nsCSPParser::requireSRIForDirectiveValue(nsRequireSRIForDirective* aDir) { CSPPARSERLOG(("nsCSPParser::requireSRIForDirectiveValue")); // directive-value = "style" / "script" // directive name is token 0, we need to examine the remaining tokens 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:::directive (require-sri-for directive), " "mCurToken: %s (valid), mCurValue: %s", NS_ConvertUTF16toUTF8(mCurToken).get(), NS_ConvertUTF16toUTF8(mCurValue).get())); // add contentPolicyTypes to the CSP's required-SRI list for this token if (mCurToken.LowerCaseEqualsASCII(kScript)) { aDir->addType(nsIContentPolicy::TYPE_SCRIPT); } else if (mCurToken.LowerCaseEqualsASCII(kStyle)) { aDir->addType(nsIContentPolicy::TYPE_STYLESHEET); } else { const char16_t* invalidTokenName[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "failedToParseUnrecognizedSource", invalidTokenName, ArrayLength(invalidTokenName)); CSPPARSERLOG(("nsCSPParser:::directive (require-sri-for directive), " "mCurToken: %s (invalid), mCurValue: %s", NS_ConvertUTF16toUTF8(mCurToken).get(), NS_ConvertUTF16toUTF8(mCurValue).get())); } } if (!(aDir->hasType(nsIContentPolicy::TYPE_STYLESHEET)) && !(aDir->hasType(nsIContentPolicy::TYPE_SCRIPT))) { const char16_t* directiveName[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoringDirectiveWithNoValues", directiveName, ArrayLength(directiveName)); delete aDir; return; } mPolicy->addDirective(aDir); } void nsCSPParser::reportURIList(nsCSPDirective* aDir) { CSPPARSERLOG(("nsCSPParser::reportURIList")); nsTArray srcs; nsCOMPtr 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)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldNotParseReportURI", params, ArrayLength(params)); continue; } // Create new nsCSPReportURI and append to the list. nsCSPReportURI* reportURI = new nsCSPReportURI(uri); srcs.AppendElement(reportURI); } if (srcs.Length() == 0) { const char16_t* directiveName[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoringDirectiveWithNoValues", directiveName, ArrayLength(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)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldntParseInvalidSandboxFlag", params, ArrayLength(params)); continue; } flags.Append(mCurToken); if (i != mCurDir.Length() - 1) { flags.AppendASCII(" "); } } // Please note that the sandbox directive can exist // by itself (not containing any flags). nsTArray srcs; srcs.AppendElement(new nsCSPSandboxFlags(flags)); aDir->addSrcs(srcs); mPolicy->addDirective(aDir); } // directive-value = *( WSP / ) void nsCSPParser::directiveValue(nsTArray& 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) || (!sCSPExperimentalEnabled && CSP_IsDirective(mCurToken, nsIContentSecurityPolicy::REQUIRE_SRI_FOR))) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "couldNotProcessUnknownDirective", params, ArrayLength(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)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "notSupportingDirective", params, ArrayLength(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))) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "duplicateDirective", params, ArrayLength(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 const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoringSrcFromMetaCSP", params, ArrayLength(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)); } // child-src by itself is deprecatd but will be enforced // * for workers (if worker-src is not explicitly specified) // * for frames (if frame-src is not explicitly specified) if (CSP_IsDirective(mCurToken, nsIContentSecurityPolicy::CHILD_SRC_DIRECTIVE)) { const char16_t* params[] = { mCurToken.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "deprecatedChildSrcDirective", params, ArrayLength(params)); 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; } if (CSP_IsDirective(mCurToken, nsIContentSecurityPolicy::REQUIRE_SRI_FOR)) { return new nsRequireSRIForDirective(CSP_StringToCSPDirective(mCurToken)); } 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) { const char16_t* params[] = { u"directive missing" }; logWarningErrorToConsole(nsIScriptError::warningFlag, "failedToParseUnrecognizedSource", params, ArrayLength(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) { const char16_t* params[] = { u"block-all-mixed-content" }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoreSrcForDirective", params, ArrayLength(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) { const char16_t* params[] = { u"upgrade-insecure-requests" }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoreSrcForDirective", params, ArrayLength(params)); } // add the directive and return mPolicy->addUpgradeInsecDir(static_cast(cspDir)); return; } // special case handling for require-sri-for, which has directive values that // are well-defined tokens but are not sources if (cspDir->equals(nsIContentSecurityPolicy::REQUIRE_SRI_FOR)) { requireSRIForDirectiveValue(static_cast(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 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.Length() == 0) { nsCSPKeywordSrc *keyword = new nsCSPKeywordSrc(CSP_NONE); srcs.AppendElement(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, NS_LITERAL_STRING("'sha"))) { const char16_t* params[] = { srcStr.get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoringSrcForStrictDynamic", params, ArrayLength(params)); } } // Log a warning that all scripts might be blocked because the policy contains // 'strict-dynamic' but no valid nonce or hash. if (!mHasHashOrNonce) { const char16_t* params[] = { mCurDir[0].get() }; logWarningErrorToConsole(nsIScriptError::warningFlag, "strictDynamicButNoHashOrNonce", params, ArrayLength(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 const char16_t* params[] = { u"'unsafe-inline'" }; logWarningErrorToConsole(nsIScriptError::warningFlag, "ignoringSrcWithinScriptStyleSrc", params, ArrayLength(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]; 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< nsTArray > 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); NS_ConvertUTF8toUTF16 unicodePrePath(prePath); const char16_t* params[] = { unicodePrePath.get() }; parser.logWarningErrorToConsole(nsIScriptError::warningFlag, "reportURInotInReportOnlyHeader", params, ArrayLength(params)); } } 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; }