From 2f9e5485153928799e62744839cec799ed17fa16 Mon Sep 17 00:00:00 2001
From: jdh8d <jdh8d@git.zephyr-software.com>
Date: Wed, 21 Oct 2015 12:56:20 +0000
Subject: [PATCH] update to allow controlling of random seed and canary-value
that's used
Former-commit-id: ad0f88e86e87a46ec42691e084ae869d8cdaa198
---
tools/transforms/PNMain.cpp | 20 +++++++++++++++++++-
tools/transforms/PNTransformDriver.cpp | 16 ++++++++++++++--
tools/transforms/globals.h | 20 +++++++++++++++++++-
3 files changed, 52 insertions(+), 4 deletions(-)
diff --git a/tools/transforms/PNMain.cpp b/tools/transforms/PNMain.cpp
index 9b96d488c..3973f2d10 100644
--- a/tools/transforms/PNMain.cpp
+++ b/tools/transforms/PNMain.cpp
@@ -71,7 +71,9 @@ enum
RECURSIVE_MIN_STACK_PAD_OPTION,
RECURSIVE_MAX_STACK_PAD_OPTION,
SHOULD_DOUBLE_FRAME_SIZE_OPTION,
- SELECTIVE_CANARIES_OPTION
+ SELECTIVE_CANARIES_OPTION,
+ SET_RANDOM_SEED,
+ SET_CANARY_VALUE
};
@@ -96,6 +98,8 @@ static struct option const long_options[] =
{"recursive_max_stack_padding",required_argument, NULL, RECURSIVE_MAX_STACK_PAD_OPTION},
{"should_double_frame_size",required_argument, NULL, SHOULD_DOUBLE_FRAME_SIZE_OPTION},
{"selective_canaries",required_argument, NULL, SELECTIVE_CANARIES_OPTION},
+ {"random_seed",required_argument, NULL, SET_RANDOM_SEED},
+ {"canary_value",required_argument, NULL, SET_CANARY_VALUE},
{NULL, 0, NULL, 0}
};
@@ -362,6 +366,20 @@ int main(int argc, char **argv)
break;
}
+ case SET_RANDOM_SEED:
+ {
+ int the_seed=atoi(optarg);
+ cout<<"Setting random seed to: "<<the_seed<<endl;
+ pn_options->setRandomSeed(the_seed);
+ break;
+ }
+ case SET_CANARY_VALUE:
+ {
+ int the_val=strtoul(optarg, NULL, 0);
+ cout<<"Setting canary value to: 0x"<<hex<<the_val<<endl;
+ pn_options->setCanaryValue(the_val);
+ break;
+ }
case '?':
{
//error message already printed by getopt_long
diff --git a/tools/transforms/PNTransformDriver.cpp b/tools/transforms/PNTransformDriver.cpp
index c2d1a43e3..a48fe4d1d 100644
--- a/tools/transforms/PNTransformDriver.cpp
+++ b/tools/transforms/PNTransformDriver.cpp
@@ -101,7 +101,8 @@ PNTransformDriver::PNTransformDriver(VariantID_t *pidp,string BED_script, pqxxDB
{
//TODO: throw exception?
assert(pidp != NULL);
- srand(time(NULL));
+
+ srand(pn_options->getRandomSeed());
//TODO: throw exception?
this->pidp = pidp;
@@ -2162,17 +2163,28 @@ bool PNTransformDriver::Validate(FileIR_t *virp, string name)
unsigned int PNTransformDriver::GetRandomCanary()
{
+ /* get a canary value from the options.
+ * assume the options package is returning a full 32-bits of entropy.
+ */
+ return pn_options->getCanaryValue();
+
+#if 0
+/* note: this code is being careful to get a full 32-bits of entropy, and rand() is only promising 16-bits of entropy.
+ */
//TODO: check for bias.
stringstream canary;
canary.str("");
+
+ //canary<<hex<<pn_options->GetCanaryValue();
for(int i=0;i<8;i++)
{
- canary<<hex<<(rand()%16);
+ canary<<hex<< (rand()%16);
}
unsigned int ret_val;
sscanf(canary.str().c_str(),"%x",&ret_val);
return ret_val;
+#endif
}
bool PNTransformDriver::Canary_Rewrite(PNStackLayout *orig_layout, Function_t *func)
diff --git a/tools/transforms/globals.h b/tools/transforms/globals.h
index c9b51c251..feaf87ce1 100644
--- a/tools/transforms/globals.h
+++ b/tools/transforms/globals.h
@@ -23,6 +23,8 @@
#include <set>
#include <string>
+#include <stdlib.h>
+
extern bool verbose_log;
@@ -37,8 +39,11 @@ class PNOptions
recursive_min_stack_padding = 32;
recursive_max_stack_padding = 64;
do_canaries = true;
- do_selective_canaries = true;
+ do_selective_canaries = false;
should_double_frame_size=true;
+ random_seed=time(0);
+ canary_value=0;
+ canary_value_inited=false;
}
void setMinStackPadding(int val) { min_stack_padding = val; }
@@ -46,12 +51,22 @@ class PNOptions
void setRecursiveMinStackPadding(int val) { recursive_min_stack_padding = val; }
void setRecursiveMaxStackPadding(int val) { recursive_max_stack_padding = val; }
void setShouldDoubleFrameSize(bool val) { should_double_frame_size = val; }
+ void setRandomSeed(bool val) { random_seed = val; }
+ void setCanaryValue(int val) { canary_value = val; canary_value_inited=true; }
int getMinStackPadding() const { return min_stack_padding; }
int getMaxStackPadding() const { return max_stack_padding; }
int getRecursiveMinStackPadding() const { return recursive_min_stack_padding; }
int getRecursiveMaxStackPadding() const { return recursive_max_stack_padding; }
bool getShouldDoubleFrameSize() const { return should_double_frame_size; }
+ bool getRandomSeed() { return random_seed; }
+ int getCanaryValue()
+ {
+ if (canary_value_inited)
+ return canary_value;
+ else
+ return (rand()&0xffff) | (rand()<<16);
+ }
void setDoCanaries(bool canaries) { do_canaries = canaries; }
bool getDoCanaries() const { return do_canaries; }
@@ -77,6 +92,9 @@ class PNOptions
bool do_canaries;
bool do_selective_canaries;
bool should_double_frame_size;
+ bool random_seed;
+ int canary_value;
+ bool canary_value_inited;
std::set<std::string> canary_functions;
};
--
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