summaryrefslogtreecommitdiffstats
path: root/dom/security/nsCSPParser.h
diff options
context:
space:
mode:
Diffstat (limited to 'dom/security/nsCSPParser.h')
-rw-r--r--dom/security/nsCSPParser.h262
1 files changed, 262 insertions, 0 deletions
diff --git a/dom/security/nsCSPParser.h b/dom/security/nsCSPParser.h
new file mode 100644
index 000000000..30954b10f
--- /dev/null
+++ b/dom/security/nsCSPParser.h
@@ -0,0 +1,262 @@
+/* -*- 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/. */
+
+#ifndef nsCSPParser_h___
+#define nsCSPParser_h___
+
+#include "nsCSPUtils.h"
+#include "nsIURI.h"
+#include "nsString.h"
+
+/**
+ * How does the parsing work?
+ *
+ * We generate tokens by splitting the policy-string by whitespace and semicolon.
+ * Interally the tokens are represented as an array of string-arrays:
+ *
+ * [
+ * [ name, src, src, src, ... ],
+ * [ name, src, src, src, ... ],
+ * [ name, src, src, src, ... ]
+ * ]
+ *
+ * for example:
+ * [
+ * [ img-src, http://www.example.com, http:www.test.com ],
+ * [ default-src, 'self'],
+ * [ script-src, 'unsafe-eval', 'unsafe-inline' ],
+ * ]
+ *
+ * The first element of each array has to be a valid directive-name, otherwise we can
+ * ignore the remaining elements of the array. Also, if the
+ * directive already exists in the current policy, we can ignore
+ * the remaining elements of that array. (http://www.w3.org/TR/CSP/#parsing)
+ */
+
+typedef nsTArray< nsTArray<nsString> > cspTokens;
+
+class nsCSPTokenizer {
+
+ public:
+ static void tokenizeCSPPolicy(const nsAString &aPolicyString, cspTokens& outTokens);
+
+ private:
+ nsCSPTokenizer(const char16_t* aStart, const char16_t* aEnd);
+ ~nsCSPTokenizer();
+
+ inline bool atEnd()
+ {
+ return mCurChar >= mEndChar;
+ }
+
+ inline void skipWhiteSpace()
+ {
+ while (mCurChar < mEndChar &&
+ nsContentUtils::IsHTMLWhitespace(*mCurChar)) {
+ mCurToken.Append(*mCurChar++);
+ }
+ mCurToken.Truncate();
+ }
+
+ inline void skipWhiteSpaceAndSemicolon()
+ {
+ while (mCurChar < mEndChar && (*mCurChar == ';' ||
+ nsContentUtils::IsHTMLWhitespace(*mCurChar))){
+ mCurToken.Append(*mCurChar++);
+ }
+ mCurToken.Truncate();
+ }
+
+ inline bool accept(char16_t aChar)
+ {
+ NS_ASSERTION(mCurChar < mEndChar, "Trying to dereference mEndChar");
+ if (*mCurChar == aChar) {
+ mCurToken.Append(*mCurChar++);
+ return true;
+ }
+ return false;
+ }
+
+ void generateNextToken();
+ void generateTokens(cspTokens& outTokens);
+
+ const char16_t* mCurChar;
+ const char16_t* mEndChar;
+ nsString mCurToken;
+};
+
+
+class nsCSPParser {
+
+ public:
+ /**
+ * The CSP parser only has one publicly accessible function, which is parseContentSecurityPolicy.
+ * Internally the input string is separated into string tokens and policy() is called, which starts
+ * parsing the policy. The parser calls one function after the other according the the source-list
+ * from http://www.w3.org/TR/CSP11/#source-list. E.g., the parser can only call port() after the parser
+ * has already processed any possible host in host(), similar to a finite state machine.
+ */
+ static nsCSPPolicy* parseContentSecurityPolicy(const nsAString &aPolicyString,
+ nsIURI *aSelfURI,
+ bool aReportOnly,
+ nsCSPContext* aCSPContext,
+ bool aDeliveredViaMetaTag);
+
+ private:
+ nsCSPParser(cspTokens& aTokens,
+ nsIURI* aSelfURI,
+ nsCSPContext* aCSPContext,
+ bool aDeliveredViaMetaTag);
+
+ static bool sCSPExperimentalEnabled;
+ static bool sStrictDynamicEnabled;
+
+ ~nsCSPParser();
+
+
+ // Parsing the CSP using the source-list from http://www.w3.org/TR/CSP11/#source-list
+ nsCSPPolicy* policy();
+ void directive();
+ nsCSPDirective* directiveName();
+ void directiveValue(nsTArray<nsCSPBaseSrc*>& outSrcs);
+ void requireSRIForDirectiveValue(nsRequireSRIForDirective* aDir);
+ void referrerDirectiveValue(nsCSPDirective* aDir);
+ void reportURIList(nsCSPDirective* aDir);
+ void sandboxFlagList(nsCSPDirective* aDir);
+ void sourceList(nsTArray<nsCSPBaseSrc*>& outSrcs);
+ nsCSPBaseSrc* sourceExpression();
+ nsCSPSchemeSrc* schemeSource();
+ nsCSPHostSrc* hostSource();
+ nsCSPBaseSrc* keywordSource();
+ nsCSPNonceSrc* nonceSource();
+ nsCSPHashSrc* hashSource();
+ nsCSPHostSrc* appHost(); // helper function to support app specific hosts
+ nsCSPHostSrc* host();
+ bool hostChar();
+ bool schemeChar();
+ bool port();
+ bool path(nsCSPHostSrc* aCspHost);
+
+ bool subHost(); // helper function to parse subDomains
+ bool atValidUnreservedChar(); // helper function to parse unreserved
+ bool atValidSubDelimChar(); // helper function to parse sub-delims
+ bool atValidPctEncodedChar(); // helper function to parse pct-encoded
+ bool subPath(nsCSPHostSrc* aCspHost); // helper function to parse paths
+
+ inline bool atEnd()
+ {
+ return mCurChar >= mEndChar;
+ }
+
+ inline bool accept(char16_t aSymbol)
+ {
+ if (atEnd()) { return false; }
+ return (*mCurChar == aSymbol) && advance();
+ }
+
+ inline bool accept(bool (*aClassifier) (char16_t))
+ {
+ if (atEnd()) { return false; }
+ return (aClassifier(*mCurChar)) && advance();
+ }
+
+ inline bool peek(char16_t aSymbol)
+ {
+ if (atEnd()) { return false; }
+ return *mCurChar == aSymbol;
+ }
+
+ inline bool peek(bool (*aClassifier) (char16_t))
+ {
+ if (atEnd()) { return false; }
+ return aClassifier(*mCurChar);
+ }
+
+ inline bool advance()
+ {
+ if (atEnd()) { return false; }
+ mCurValue.Append(*mCurChar++);
+ return true;
+ }
+
+ inline void resetCurValue()
+ {
+ mCurValue.Truncate();
+ }
+
+ bool atEndOfPath();
+ bool atValidPathChar();
+
+ void resetCurChar(const nsAString& aToken);
+
+ void logWarningErrorToConsole(uint32_t aSeverityFlag,
+ const char* aProperty,
+ const char16_t* aParams[],
+ uint32_t aParamsLength);
+
+/**
+ * When parsing the policy, the parser internally uses the following helper
+ * variables/members which are used/reset during parsing. The following
+ * example explains how they are used.
+ * The tokenizer separats all input into arrays of arrays of strings, which
+ * are stored in mTokens, for example:
+ * mTokens = [ [ script-src, http://www.example.com, 'self' ], ... ]
+ *
+ * When parsing starts, mCurdir always holds the currently processed array of strings.
+ * In our example:
+ * mCurDir = [ script-src, http://www.example.com, 'self' ]
+ *
+ * During parsing, we process/consume one string at a time of that array.
+ * We set mCurToken to the string we are currently processing; in the first case
+ * that would be:
+ * mCurToken = script-src
+ * which allows to do simple string comparisons to see if mCurToken is a valid directive.
+ *
+ * Continuing parsing, the parser consumes the next string of that array, resetting:
+ * mCurToken = "http://www.example.com"
+ * ^ ^
+ * mCurChar mEndChar (points *after* the 'm')
+ * mCurValue = ""
+ *
+ * After calling advance() the first time, helpers would hold the following values:
+ * mCurToken = "http://www.example.com"
+ * ^ ^
+ * mCurChar mEndChar (points *after* the 'm')
+ * mCurValue = "h"
+ *
+ * We continue parsing till all strings of one directive are consumed, then we reset
+ * mCurDir to hold the next array of strings and start the process all over.
+ */
+
+ const char16_t* mCurChar;
+ const char16_t* mEndChar;
+ nsString mCurValue;
+ nsString mCurToken;
+ nsTArray<nsString> mCurDir;
+
+ // helpers to allow invalidation of srcs within script-src and style-src
+ // if either 'strict-dynamic' or at least a hash or nonce is present.
+ bool mHasHashOrNonce; // false, if no hash or nonce is defined
+ bool mStrictDynamic; // false, if 'strict-dynamic' is not defined
+ nsCSPKeywordSrc* mUnsafeInlineKeywordSrc; // null, otherwise invlidate()
+
+ // cache variables for child-src and frame-src directive handling.
+ // frame-src is deprecated in favor of child-src, however if we
+ // see a frame-src directive, it takes precedence for frames and iframes.
+ // At the end of parsing, if we have a child-src directive, we need to
+ // decide whether it will handle frames, or if there is a frame-src we
+ // should honor instead.
+ nsCSPChildSrcDirective* mChildSrc;
+ nsCSPDirective* mFrameSrc;
+
+ cspTokens mTokens;
+ nsIURI* mSelfURI;
+ nsCSPPolicy* mPolicy;
+ nsCSPContext* mCSPContext; // used for console logging
+ bool mDeliveredViaMetaTag;
+};
+
+#endif /* nsCSPParser_h___ */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-19 16:13:41 +0000