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Diffstat (limited to 'dom/security/nsCSPParser.cpp')
| -rw-r--r-- | dom/security/nsCSPParser.cpp | 1164 |
1 files changed, 1164 insertions, 0 deletions
diff --git a/dom/security/nsCSPParser.cpp b/dom/security/nsCSPParser.cpp new file mode 100644 index 0000000000..4a3ee07373 --- /dev/null +++ b/dom/security/nsCSPParser.cpp @@ -0,0 +1,1164 @@ +/* -*- 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/dom/Document.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; +using namespace mozilla::dom; + +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 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'); +} + +bool isNumberToken(char16_t aSymbol) { + return (aSymbol >= '0' && aSymbol <= '9'); +} + +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, + u""_ns, // aSourceName + u""_ns, // 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)) { + 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 + CSPDirective directive = CSP_StringToCSPDirective(mCurToken); + if (directive == nsIContentSecurityPolicy::NO_DIRECTIVE) { + 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 (directive == 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 (directive == 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(directive)) { + 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 && + ((directive == nsIContentSecurityPolicy::REPORT_URI_DIRECTIVE) || + (directive == nsIContentSecurityPolicy::FRAME_ANCESTORS_DIRECTIVE) || + (directive == 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 (directive == nsIContentSecurityPolicy::BLOCK_ALL_MIXED_CONTENT) { + return new nsBlockAllMixedContentDirective(directive); + } + + // special case handling for upgrade-insecure-requests + if (directive == nsIContentSecurityPolicy::UPGRADE_IF_INSECURE_DIRECTIVE) { + return new nsUpgradeInsecureDirective(directive); + } + + // 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 (directive == nsIContentSecurityPolicy::CHILD_SRC_DIRECTIVE) { + mChildSrc = new nsCSPChildSrcDirective(directive); + return mChildSrc; + } + + // if we have a frame-src, cache it so we can discard child-src for frames + if (directive == nsIContentSecurityPolicy::FRAME_SRC_DIRECTIVE) { + mFrameSrc = new nsCSPDirective(directive); + return mFrameSrc; + } + + // if we have a worker-src, cache it so we can discard child-src for workers + if (directive == nsIContentSecurityPolicy::WORKER_SRC_DIRECTIVE) { + mWorkerSrc = new nsCSPDirective(directive); + return mWorkerSrc; + } + + // if we have a script-src, cache it as a fallback for worker-src + // in case child-src is not present + if (directive == nsIContentSecurityPolicy::SCRIPT_SRC_DIRECTIVE) { + mScriptSrc = new nsCSPScriptSrcDirective(directive); + return mScriptSrc; + } + + return new nsCSPDirective(directive); +} + +// 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; +} |