Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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;
+}