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-rw-r--r--core/fxcrt/fx_basic_util.cpp41
-rw-r--r--core/fxcrt/fx_basic_util_unittest.cpp47
2 files changed, 84 insertions, 4 deletions
diff --git a/core/fxcrt/fx_basic_util.cpp b/core/fxcrt/fx_basic_util.cpp
index abd84a864f..663ca93e9c 100644
--- a/core/fxcrt/fx_basic_util.cpp
+++ b/core/fxcrt/fx_basic_util.cpp
@@ -16,8 +16,15 @@
#include <algorithm>
#include <cctype>
+#include <limits>
#include <memory>
+namespace {
+
+const int kDefaultIntValue = 0;
+
+} // namespace
+
bool FX_atonum(const CFX_ByteStringC& strc, void* pData) {
if (strc.Find('.') != -1) {
FX_FLOAT* pFloat = static_cast<FX_FLOAT*>(pData);
@@ -25,26 +32,52 @@ bool FX_atonum(const CFX_ByteStringC& strc, void* pData) {
return false;
}
- int cc = 0;
- pdfium::base::CheckedNumeric<int> integer = 0;
+ // Note, numbers in PDF are typically of the form 123, -123, etc. But,
+ // for things like the Permissions on the encryption hash the number is
+ // actually an unsigned value. We use a uint32_t so we can deal with the
+ // unsigned and then check for overflow if the user actually signed the value.
+ // The Permissions flag is listed in Table 3.20 PDF 1.7 spec.
+ pdfium::base::CheckedNumeric<uint32_t> integer = 0;
bool bNegative = false;
+ bool bSigned = false;
+ int cc = 0;
if (strc[0] == '+') {
cc++;
+ bSigned = true;
} else if (strc[0] == '-') {
bNegative = true;
+ bSigned = true;
cc++;
}
+
while (cc < strc.GetLength() && std::isdigit(strc[cc])) {
integer = integer * 10 + FXSYS_toDecimalDigit(strc.CharAt(cc));
if (!integer.IsValid())
break;
cc++;
}
+
+ // We have a sign, and the value was greater then a regular integer
+ // we've overflowed, reset to the default value.
+ if (bSigned) {
+ if (bNegative) {
+ if (integer.ValueOrDefault(kDefaultIntValue) >
+ static_cast<uint32_t>(std::numeric_limits<int>::max()) + 1) {
+ integer = kDefaultIntValue;
+ }
+ } else if (integer.ValueOrDefault(kDefaultIntValue) >
+ static_cast<uint32_t>(std::numeric_limits<int>::max())) {
+ integer = kDefaultIntValue;
+ }
+ }
+
+ // Switch back to the int space so we can flip to a negative if we need.
+ int value = static_cast<int>(integer.ValueOrDefault(kDefaultIntValue));
if (bNegative)
- integer = -integer;
+ value = -value;
int* pInt = static_cast<int*>(pData);
- *pInt = integer.ValueOrDefault(0);
+ *pInt = value;
return true;
}
diff --git a/core/fxcrt/fx_basic_util_unittest.cpp b/core/fxcrt/fx_basic_util_unittest.cpp
index 3272eab70c..6eae6696ad 100644
--- a/core/fxcrt/fx_basic_util_unittest.cpp
+++ b/core/fxcrt/fx_basic_util_unittest.cpp
@@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
+#include <limits>
+
#include "core/fxcrt/include/fx_basic.h"
#include "testing/fx_string_testhelpers.h"
#include "testing/gtest/include/gtest/gtest.h"
@@ -28,3 +30,48 @@ TEST(fxge, GetBits32) {
}
}
}
+
+TEST(fxcrt, FX_atonum) {
+ int i;
+ EXPECT_TRUE(FX_atonum("10", &i));
+ EXPECT_EQ(10, i);
+
+ EXPECT_TRUE(FX_atonum("-10", &i));
+ EXPECT_EQ(-10, i);
+
+ EXPECT_TRUE(FX_atonum("+10", &i));
+ EXPECT_EQ(10, i);
+
+ EXPECT_TRUE(FX_atonum("-2147483648", &i));
+ EXPECT_EQ(std::numeric_limits<int>::min(), i);
+
+ EXPECT_TRUE(FX_atonum("2147483647", &i));
+ EXPECT_EQ(2147483647, i);
+
+ // Value overflows.
+ EXPECT_TRUE(FX_atonum("-2147483649", &i));
+ EXPECT_EQ(0, i);
+
+ // Value overflows.
+ EXPECT_TRUE(FX_atonum("+2147483648", &i));
+ EXPECT_EQ(0, i);
+
+ // Value overflows.
+ EXPECT_TRUE(FX_atonum("4223423494965252", &i));
+ EXPECT_EQ(0, i);
+
+ // No explicit sign will allow the number to go negative. This is for things
+ // like the encryption Permissions flag (Table 3.20 PDF 1.7 spec)
+ EXPECT_TRUE(FX_atonum("4294965252", &i));
+ EXPECT_EQ(-2044, i);
+
+ EXPECT_TRUE(FX_atonum("-4294965252", &i));
+ EXPECT_EQ(0, i);
+
+ EXPECT_TRUE(FX_atonum("+4294965252", &i));
+ EXPECT_EQ(0, i);
+
+ float f;
+ EXPECT_FALSE(FX_atonum("3.24", &f));
+ EXPECT_FLOAT_EQ(3.24f, f);
+}