/
taintAnalysis.go
1308 lines (1224 loc) · 41.6 KB
/
taintAnalysis.go
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package analysis
import (
"fmt"
"go/types"
"log"
"sort"
"strings"
"github.com/xlab-uiuc/acto/ssa/util"
. "github.com/xlab-uiuc/acto/ssa/util"
"golang.org/x/tools/go/callgraph"
"golang.org/x/tools/go/ssa"
)
// Alloc
// BinOp
// Call
// ChangeInterface
// ChangeType
// Convert
// DebugRef
// Defer
// Extract
// Field
// FieldAddr
// Go
// If
// Index
// IndexAddr
// Jump
// Lookup
// MakeChan
// MakeClosure
// MakeInterface
// MakeMap
// MakeSlice
// MapUpdate
// Next
// Panic
// Phi
// Range
// Return
// RunDefers
// Select
// Send
// Slice
// SliceToArrayPointer
// Store
// TypeAssert
// UnOp
func TaintAnalysisPass(context *Context, prog *ssa.Program, frontierValues map[ssa.Value]bool, valueFieldMap map[ssa.Value]*FieldSet) *FieldSet {
tainted := make(map[ssa.Value]bool)
taintedFieldSet := NewFieldSet()
for value := range frontierValues {
backCallStack := NewCallStack()
// if value.String() == "make any <- string (t5)" && value.Parent().String() == "github.com/rabbitmq/cluster-operator/internal/resource.generateVaultTLSTemplate" {
// if TaintK8sFromValue(value, valueFieldMap, callGraph, backCallStack) {
// tainted[value] = true
// log.Printf("Value [%s] taints", value.String())
// } else {
// log.Printf("Value [%s] with path [%s] does not taint", value.String(), valueFieldMap[value].Fields())
// }
// }
log.Printf("Checking if value [%s] in function [%s] taints\n", value.String(), value.Parent().String())
if TaintK8sFromValue(context, value, value, valueFieldMap, context.CallGraph, backCallStack, false) {
tainted[value] = true
log.Printf("Value [%s] with path [%s] taint", value.String(), valueFieldMap[value].Fields())
} else {
log.Printf("Value [%s] with path [%s] does not taint", value.String(), valueFieldMap[value].Fields())
}
}
for tainted := range tainted {
for _, path := range valueFieldMap[tainted].Fields() {
log.Printf("Path [%s] taints\n", path.Path)
taintedFieldSet.Add(&path)
}
log.Printf("value %s with path %s\n", tainted, valueFieldMap[tainted])
// tainted.Parent().WriteTo(log.Writer())
}
for field, fs := range context.FieldDataDependencyMap {
if taintedFieldSet.Contain(*FieldFromString(field)) {
for _, dep := range fs.Fields() {
taintedFieldSet.Add(&dep)
}
}
}
DumpKnownFunctions()
return taintedFieldSet
}
// Represent a uniqle taint candidate
type ReferredInstruction struct {
Instruction ssa.Instruction
Value ssa.Value
}
// returns true if value taints k8s API calls
func TaintK8sFromValue(context *Context, value ssa.Value, originalValue ssa.Value, valueFieldMap map[ssa.Value]*FieldSet, callGraph *callgraph.Graph, backCallStack *CallStack, fromArg bool) bool {
log.Printf("Checking if value [%s] in function [%s] taints\n", value.String(), value.Parent().String())
// Maintain backCallStack
functionCall := FunctionCall{
FunctionName: value.Parent().String(),
TaintSource: fmt.Sprint(value),
}
if backCallStack.Contain(functionCall) {
log.Printf("Recursive taint detected, directly return %s\n", functionCall)
return false
} else {
backCallStack.Push(functionCall)
defer backCallStack.Pop()
}
// Initialize the tainted set
// The taint analysis surrounds this taintedSet map
// Whenever a value is tainted, it is added to this map
// Whenever we add a new value to this map, we change the variable `changed` to true
// If no new value is tainted in one iteration, we stop the tainting and return
taintedSet := make(map[ssa.Value]bool)
taintedSet[value] = true
// do a backward propogation on the taint source
// similar to intraprocedural pointer analysis
if IsPointerType(value) && fromArg {
taintedParamIndex, _ := BackwardPropogation(value, taintedSet)
if taintedParamIndex != -1 {
node := callGraph.Nodes[value.Parent()]
for _, inEdge := range node.In {
// XXX avoid going into external libs
if IsK8sStaticFunction(inEdge.Site.Parent()) {
return true
}
var taintedParam ssa.Value
if inEdge.Site.Common().IsInvoke() {
// if the callsite is an invoke, we need to decrement the param index
// because invoke call does not have receiver in parameter
localParamIndex := taintedParamIndex - 1
if localParamIndex == -1 {
// taint the receiver
taintedParam = inEdge.Site.Common().Value
} else {
taintedParam = inEdge.Site.Common().Args[localParamIndex]
}
} else {
taintedParam = inEdge.Site.Common().Args[taintedParamIndex]
}
if TaintK8sFromValue(context, taintedParam, originalValue, valueFieldMap, callGraph, backCallStack, true) {
return true
}
}
}
}
// cache
// when we finish tainting all the referrers of a value, no need to taint again
propogatedSet := make(map[ssa.Value]bool)
callStack := NewCallStack()
callStack.Push(functionCall)
for {
changed := false
for taintedValue := range taintedSet {
if _, ok := propogatedSet[taintedValue]; ok {
log.Printf("The value %s is already propogated\n", taintedValue)
continue
}
referrers := taintedValue.Referrers()
for _, instruction := range *referrers {
// XXX: Need to maintain a callstack to handle recursive functions
switch typedInst := instruction.(type) {
case ssa.Value:
switch typedValue := typedInst.(type) {
case *ssa.Alloc:
// skip
log.Panic("Alloc referred\n")
case *ssa.BinOp:
// propogate to the result
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Call:
// context aware
if typedValue.Parent().Pkg != nil {
log.Printf("Propogate to callee %s at %s\n", typedValue.String(), typedValue.Parent().Pkg.Prog.Fset.Position(typedValue.Pos()))
} else {
log.Printf("Propogate to shared callee %s \n", typedValue.String())
}
end, taintedArgs, taintedRets := ContextAwareFunctionAnalysis(context, taintedValue, typedValue, callGraph, taintedSet, valueFieldMap, callStack)
if end {
return true
}
for _, taintedArg := range taintedArgs {
if _, ok := taintedSet[taintedArg]; !ok {
taintedSet[taintedArg] = true
changed = true
}
// TODO: backward propogation in case of map, pointer, slice, interface
switch taintedArg.Type().(type) {
case *types.Map:
end, chg := handlePointerArgBackwardPropogation(context, taintedArg, originalValue, valueFieldMap, taintedSet, callGraph, backCallStack)
if end {
return true
}
if chg {
changed = true
}
case *types.Pointer:
end, chg := handlePointerArgBackwardPropogation(context, taintedArg, originalValue, valueFieldMap, taintedSet, callGraph, backCallStack)
if end {
return true
}
if chg {
changed = true
}
case *types.Slice:
end, chg := handlePointerArgBackwardPropogation(context, taintedArg, originalValue, valueFieldMap, taintedSet, callGraph, backCallStack)
if end {
return true
}
if chg {
changed = true
}
case *types.Interface:
end, chg := handlePointerArgBackwardPropogation(context, taintedArg, originalValue, valueFieldMap, taintedSet, callGraph, backCallStack)
if end {
return true
}
if chg {
changed = true
}
}
}
for _, taintedRet := range taintedRets {
if _, ok := taintedSet[taintedRet]; !ok {
taintedSet[taintedRet] = true
changed = true
}
}
case *ssa.ChangeInterface:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.ChangeType:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Extract:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Field:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.FieldAddr:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Index:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.IndexAddr:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Lookup:
// Two cases: 1) referred as the X 2) referred as the Index
if taintedValue == typedValue.X {
if typedValue.CommaOk {
if handleExtractTaint(typedValue, &taintedSet, []int{0, 1}) {
changed = true
}
} else {
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
}
} else {
// skip
log.Printf("Referred as Index in Lookup\n")
}
case *ssa.MakeChan:
// skip
case *ssa.MakeClosure:
log.Println("Propogate to closure function as freevar")
// compute the index of tainted freevar
indices := []ssa.Value{}
for i, binding := range typedValue.Bindings {
if binding == taintedValue {
freeVar := typedValue.Fn.(*ssa.Function).FreeVars[i]
indices = append(indices, freeVar)
}
}
end, _, _ := TaintFunction(context, typedValue.Fn.(*ssa.Function), indices, callGraph, valueFieldMap, callStack)
if end {
return true
}
// XXX: this may taint the return value and other freevars
// this also could be used in k8s library functions
case *ssa.MakeInterface:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.MakeMap:
// skip
case *ssa.MakeSlice:
// skip
case *ssa.Next:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Phi:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Range:
// TODO
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Select:
log.Fatalf("Referred in Select\n")
case *ssa.Slice:
// Two cases: 1) referred as the X 2) referred as the Low, High, Max
if taintedValue == typedValue.X {
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
}
// do not propogate in 2) case
case *ssa.TypeAssert:
if typedValue.CommaOk {
// returns a tuple, need to extract
if handleExtractTaint(typedValue, &taintedSet, []int{0, 1}) {
changed = true
}
} else {
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
}
case *ssa.UnOp:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
default:
log.Printf("Hit sink %T\n", typedValue)
}
case *ssa.DebugRef:
// skip
case *ssa.Defer:
ContextAwareFunctionAnalysis(context, taintedValue, typedInst, callGraph, taintedSet, valueFieldMap, callStack)
case *ssa.Go:
ContextAwareFunctionAnalysis(context, taintedValue, typedInst, callGraph, taintedSet, valueFieldMap, callStack)
case *ssa.If:
// skip
case *ssa.Jump:
// skip
case *ssa.MapUpdate:
// TODO: field sensitive taint
// Three cases
// 1) used as Map
// 2) used as Key - taint Map
// 3) used as Value - taint Map
// Need to further taint backward, because map is pass by reference
if taintedValue == typedInst.Key {
if _, ok := taintedSet[typedInst.Map]; !ok {
log.Printf("%s -> %s\n", taintedValue, typedInst.Map)
taintedSet[typedInst.Map] = true
changed = true
}
} else if taintedValue == typedInst.Value {
if _, ok := taintedSet[typedInst.Map]; !ok {
log.Printf("%s -> %s\n", taintedValue, typedInst.Map)
taintedSet[typedInst.Map] = true
changed = true
}
end, chg := handlePointerArgBackwardPropogation(context, typedInst.Map, originalValue, valueFieldMap, taintedSet, callGraph, backCallStack)
if end {
return true
}
if chg {
changed = true
}
// XXX: Handle parameter
if param, ok := typedInst.Map.(*ssa.Parameter); ok {
// updating map directly from the parameter
// since map is pass by reference, need to taint to callsite
// Figure out the parameter index at function body
paramIndex := GetCalleeParamIndex(param, typedInst.Parent())
node := callGraph.Nodes[taintedValue.Parent()]
for _, inEdge := range node.In {
if IsK8sStaticFunction(inEdge.Site.Parent()) {
return true
}
// Two cases:
// 1) Callsite is an invoke
// 2) Callsite is ordinary function call
// We need to distinguish here because the parameter index will be different
localParamIndex := paramIndex
if inEdge.Site.Common().IsInvoke() {
// in invoke case, we need to decrement the parameter index
// because the receiver is not in the parameter
localParamIndex--
}
callsiteParamValue := inEdge.Site.Common().Args[localParamIndex]
if TaintK8sFromValue(context, callsiteParamValue, originalValue, valueFieldMap, callGraph, backCallStack, true) {
return true
}
}
}
}
case *ssa.Panic:
// skip
case *ssa.Return:
// Find all possible callsites, taint the return value
// find the tainted index in the returned value (hanlde the case of returning tuple)
// TODO Handle call stack carefully here
taintedReturnSet := GetReturnIndices(taintedValue, typedInst)
node, ok := callGraph.Nodes[taintedValue.Parent()]
if !ok {
log.Printf("Failed to retrieve call graph node for %s %T\n", taintedValue, taintedValue)
}
if node == nil {
log.Printf("No caller for %s %T at %s\n", taintedValue, taintedValue, taintedValue.Parent().Pkg.Prog.Fset.Position(taintedValue.Pos()))
} else {
for _, inEdge := range node.In {
// if it returns to a K8s client function, return true to end
if IsK8sStaticFunction(inEdge.Site.Parent()) {
return true
}
if callSiteReturnValue := inEdge.Site.Value(); callSiteReturnValue != nil {
if typedInst.Parent().Signature.Results().Len() > 1 {
// if return value is a tuple
// propogate to the callsite recursively
for _, tainted := range getExtractTaint(callSiteReturnValue, taintedReturnSet) {
if TaintK8sFromValue(context, tainted, originalValue, valueFieldMap, callGraph, backCallStack, false) {
return true
}
}
} else {
log.Printf("Propogate to the callsites %s from function %s\n", inEdge.Site.Parent().String(), typedInst.Parent())
if TaintK8sFromValue(context, callSiteReturnValue, originalValue, valueFieldMap, callGraph, backCallStack, false) {
return true
}
}
} else {
log.Fatalf("return to a non-call callsite from function %s\n", taintedValue.Parent().Pkg.Prog.Fset.Position(taintedValue.Pos()))
}
}
}
case *ssa.RunDefers:
// skip
case *ssa.Send:
// Two cases
// used as X
// used as Chan
case *ssa.Store:
// TODO: propogate back
// Two cases
// used as Addr
// used as Val
if taintedValue == typedInst.Val {
// used as Val, propogate back
// XXX need to taint to callsite
if addrFieldSet, ok := context.ValueToFieldNodeSetMap[typedInst.Addr]; ok {
// if val is stored into a CR field, don't run backward propogation
// handle this case later
for addrField := range addrFieldSet {
if fs, ok := context.FieldDataDependencyMap[addrField.EncodedPath()]; ok {
fs.Extend(valueFieldMap[originalValue])
} else {
newFieldSet := util.NewFieldSet()
newFieldSet.Extend(valueFieldMap[originalValue])
context.FieldDataDependencyMap[addrField.EncodedPath()] = newFieldSet
}
}
} else {
taintedParamIndex, chg := BackwardPropogation(typedInst.Addr, taintedSet)
if chg {
changed = true
}
if taintedParamIndex != -1 {
node := callGraph.Nodes[taintedValue.Parent()]
for _, inEdge := range node.In {
// XXX avoid going into external libs
if IsK8sStaticFunction(inEdge.Site.Parent()) {
return true
}
// if !strings.Contains(inEdge.Site.Parent().Pkg.String(), "github.com/rabbitmq/cluster-operator") {
// if IsK8sStaticFunction(inEdge.Site.Parent()) {
// return true
// }
// continue
// }
var taintedParam ssa.Value
localTaintedParamIndex := taintedParamIndex
if inEdge.Site.Common().IsInvoke() {
// if the callsite is an invoke, we need to decrement the param index
// because invoke call does not have receiver in parameter
localTaintedParamIndex--
if localTaintedParamIndex == -1 {
// taint the receiver
taintedParam = inEdge.Site.Common().Value
} else {
taintedParam = inEdge.Site.Common().Args[localTaintedParamIndex]
}
} else {
taintedParam = inEdge.Site.Common().Args[localTaintedParamIndex]
}
if TaintK8sFromValue(context, taintedParam, originalValue, valueFieldMap, callGraph, backCallStack, true) {
return true
}
}
}
}
}
default:
log.Printf("Hit sink %T\n", typedInst)
}
}
propogatedSet[taintedValue] = true
}
if !changed {
break
}
}
return false
}
// only taint the callsite
// returns if the taint hits k8s client call, if taintedSet is updated
//
// Params:
// @value is the source of the taint
// @callInst is the call instruction
//
// TODO: XXX Do backward propogation for tainted parameters
func ContextAwareFunctionAnalysis(context *Context, value ssa.Value, callInst ssa.CallInstruction, callGraph *callgraph.Graph,
taintedSet map[ssa.Value]bool, valueFieldMap map[ssa.Value]*FieldSet,
callStack *CallStack) (end bool, taintedArgs []ssa.Value, taintedRets []ssa.Value) {
end = false
callSiteTaintedArgIndexSet := GetCallsiteArgIndices(value, callInst.Common())
if value.Parent().Pkg != nil {
log.Printf("Propogate to callee %s at %s with args %v\n", callInst.String(), callInst.Parent().Pkg.Prog.Fset.Position(callInst.Pos()), callSiteTaintedArgIndexSet)
} else {
log.Printf("Propogate to shared callee %s \n", callInst.String())
}
if callInst.Common().IsInvoke() {
// invoke case
// dynamic dispatched call, use callGraph to find all possible callees
// determine if the callee is sink
if IsInterfaceFunctionSink(callInst.Common().Method) {
end = false
return
}
if IsK8sInterfaceFunction(callInst.Common().Method) {
end = true
return
}
// callValue is the ret value of the call instruction
if callValue := callInst.Value(); callValue != nil {
taintedArgSet := NewSet[int]()
taintedRetSet := NewSet[int]()
// construct this function call signiture
functionCall := FunctionCall{
FunctionName: callInst.Common().Method.FullName(),
TaintSource: fmt.Sprint(callSiteTaintedArgIndexSet),
}
if taintResult := GetKnownInterfaceFunction(functionCall); taintResult != nil {
endCache := taintResult.End
taintedArgsCache := taintResult.TaintedArgs
taintedRetsCache := taintResult.TaintedRets
if endCache {
end = true
return
}
for _, taintedParam := range taintedArgsCache {
taintedArgSet.Add(taintedParam)
}
for _, taintedRet := range taintedRetsCache {
taintedRetSet.Add(taintedRet)
}
} else {
if !strings.Contains(callInst.Common().Method.Pkg().Path(), context.RootModule.Path) {
log.Printf("Interface Callee [%s] in package [%s] is in external library\n", callInst.Common().Method.FullName(), callInst.Common().Method.Pkg().Path())
}
calleeSet := CalleeSet(callGraph, callInst)
if len(calleeSet) > 20 {
log.Printf("Found more than 20 possible callees, skip\n")
return
}
// iterate through all the possible callees
for _, callee := range calleeSet {
log.Printf("Propogate into concrete callee %s\n", callee.String())
// initialize the entryPoints to taint when propogating to the callee
// 1) taint the parameters
// Caveat: the callsite is invoke, the callee is concrete function
// the parameter index should be offset because the callee's parameter
// contains the receiver
entryPoints := []ssa.Value{}
for _, callSiteTaintedArgIndex := range callSiteTaintedArgIndexSet {
entryPoints = append(entryPoints, callee.Params[callSiteTaintedArgIndex+1])
}
// Run recursive function and check if the parameter is tainted
endCache, taintedArgsCache, taintedRetsCache := TaintFunction(context, callee,
entryPoints, callGraph, valueFieldMap, callStack)
if endCache {
end = true
break
}
// Note: we offset Parameter index here because the args at invoke callsite does
// not contain receiver
for _, taintedParam := range taintedArgsCache {
taintedArgSet.Add(taintedParam - 1)
}
for _, taintedRet := range taintedRetsCache {
taintedRetSet.Add(taintedRet)
}
}
}
// Save the taint result in map
KnownInterfaceFunction[functionCall] = FunctionTaintResult{
End: end,
TaintedArgs: taintedArgSet.Items(),
TaintedRets: taintedRetSet.Items(),
}
if end {
return
}
// taint the callsite's return values
resultTuple := callInst.Common().Signature().Results()
if resultTuple != nil && taintedRetSet.Len() > 0 {
if resultTuple.Len() > 1 {
// handle extract
taintedRets = append(taintedRets, getExtractTaint(callValue, taintedRetSet.Items())...)
} else {
taintedRets = append(taintedRets, callValue)
}
}
// taint the callsite's parameter values
for _, taintedArgIndex := range taintedArgSet.Items() {
var taintedArg ssa.Value
if taintedArgIndex == -1 {
// receiver is tainted
taintedArg = callInst.Common().Value
} else {
taintedArg = callInst.Common().Args[taintedArgIndex]
}
taintedArgs = append(taintedArgs, taintedArg)
}
}
// ELSE Go, Defer instruction
} else {
// ordinary call case
switch callee := callInst.Common().Value.(type) {
case *ssa.Function:
if IsStaticFunctionSink(callee) {
return
}
if IsK8sStaticFunction(callee) {
end = true
return
}
if callValue := callInst.Value(); callValue != nil {
// if it's a Call instruction
if taintResult := GetKnownStaticFunction(callee, callSiteTaintedArgIndexSet); taintResult != nil {
endCache := taintResult.End
taintedArgsCache := taintResult.TaintedArgs
taintedRetsCache := taintResult.TaintedRets
if endCache {
end = true
return
} else if len(taintedArgsCache) == 0 && len(taintedRetsCache) == 0 {
return
}
// taint the callsite's return values
resultTuple := callee.Signature.Results()
if resultTuple != nil && len(taintedRetsCache) > 0 {
if resultTuple.Len() > 1 {
// handle extract
taintedRets = append(taintedRets, getExtractTaint(callValue, taintedRetsCache)...)
} else {
taintedRets = append(taintedRets, callValue)
}
}
// taint the callsite's parameter values
for _, taintedArgIndex := range taintedArgsCache {
taintedArg := callInst.Common().Args[taintedArgIndex]
taintedArgs = append(taintedArgs, taintedArg)
}
} else {
if !strings.Contains(callee.Pkg.Pkg.Path(), context.RootModule.Path) {
log.Printf("Static callee [%s] is in external library [%s]\n", callee.String(), callee.Pkg.Pkg.Path())
}
// initialize the entryPoints to taint when propogating to the callee
// In static call case, we only need to taint the parameter,
// as the receiver will be included in the parameter
entryPoints := []ssa.Value{}
for _, callSiteTaintedArgIndex := range callSiteTaintedArgIndexSet {
entryPoints = append(entryPoints, callee.Params[callSiteTaintedArgIndex])
}
endCache, taintedArgsCache, taintedRetsCache := TaintFunction(context, callee,
entryPoints, callGraph, valueFieldMap, callStack)
// save this taint result in cache
functionCall := FunctionCall{
FunctionName: callee.String(),
TaintSource: fmt.Sprint(callSiteTaintedArgIndexSet),
}
KnownStaticFunction[functionCall] = FunctionTaintResult{
End: endCache,
TaintedArgs: taintedArgsCache,
TaintedRets: taintedRetsCache,
}
log.Printf("Saved known static function taint result for %s\n", callee.String())
log.Printf("The saved result is %s\n", KnownStaticFunction[functionCall])
if endCache {
end = true
return
} else if len(taintedArgsCache) == 0 && len(taintedRetsCache) == 0 {
return
}
// taint the callsite's return values
resultTuple := callee.Signature.Results()
if resultTuple != nil && len(taintedRetsCache) > 0 {
if resultTuple.Len() > 1 {
// handle extract
taintedRets = append(taintedRets, getExtractTaint(callValue, taintedRetsCache)...)
} else {
taintedRets = append(taintedRets, callValue)
}
log.Printf("Returning the taintedRet set: %s\n", taintedRets)
} else if resultTuple == nil {
log.Printf("The result tuple is nil\n")
} else {
log.Printf("The length of rets is %d\n", len(taintedRetsCache))
}
// taint the callsite's parameter values
for _, taintedArgIndex := range taintedArgsCache {
taintedArg := callInst.Common().Args[taintedArgIndex]
taintedArgs = append(taintedArgs, taintedArg)
}
}
}
// Go, Defer instruction
case *ssa.MakeClosure:
functionBody := callee.Fn.(*ssa.Function)
if callValue := callInst.Value(); callValue != nil && functionBody != nil {
// initialize the entryPoints to taint when propogating to the callee
// In static call case, we only need to taint the parameter,
// as the receiver will be included in the parameter
if taintResult := GetKnownStaticFunction(functionBody, callSiteTaintedArgIndexSet); taintResult != nil {
endCache := taintResult.End
taintedArgsCache := taintResult.TaintedArgs
taintedRetsCache := taintResult.TaintedRets
if endCache {
end = true
return
} else if len(taintedArgs) == 0 && len(taintedRets) == 0 {
return
}
// taint the callsite's return values
resultTuple := functionBody.Signature.Results()
if resultTuple != nil && len(taintedRetsCache) > 0 {
if resultTuple.Len() > 1 {
// handle extract
taintedRets = append(taintedRets, getExtractTaint(callValue, taintedRetsCache)...)
} else {
taintedRets = append(taintedRets, callValue)
}
}
// taint the callsite's parameter values
for _, taintedArgIndex := range taintedArgsCache {
taintedArg := callInst.Common().Args[taintedArgIndex]
taintedArgs = append(taintedArgs, taintedArg)
}
} else {
entryPoints := []ssa.Value{}
for _, callSiteTaintedArgIndex := range callSiteTaintedArgIndexSet {
entryPoints = append(entryPoints, functionBody.Params[callSiteTaintedArgIndex])
}
endCache, taintedArgsCache, taintedRetsCache := TaintFunction(context, functionBody,
entryPoints, callGraph, valueFieldMap, callStack)
// save this taint result in cache
functionCall := FunctionCall{
FunctionName: callee.String(),
TaintSource: fmt.Sprint(callSiteTaintedArgIndexSet),
}
KnownStaticFunction[functionCall] = FunctionTaintResult{
End: endCache,
TaintedArgs: taintedArgsCache,
TaintedRets: taintedRetsCache,
}
if endCache {
end = true
return
} else if len(taintedArgsCache) == 0 && len(taintedRetsCache) == 0 {
return
}
// taint the callsite's return values
resultTuple := functionBody.Signature.Results()
if resultTuple != nil && len(taintedRetsCache) > 0 {
if resultTuple.Len() > 1 {
// handle extract
taintedRets = append(taintedRets, getExtractTaint(callValue, taintedRetsCache)...)
} else {
taintedRets = append(taintedRets, callValue)
}
}
// taint the callsite's parameter values
for _, taintedArgIndex := range taintedArgsCache {
taintedArg := callInst.Common().Args[taintedArgIndex]
taintedArgs = append(taintedArgs, taintedArg)
}
}
}
case *ssa.Builtin:
// need to define the buildins to propogate
if _, ok := BUILTIN_PROPOGATE[callee.Name()]; ok {
log.Printf("Builtin function %s, propogate to return value\n", callee.Name())
if callValue := callInst.Value(); callValue != nil {
taintedRets = append(taintedRets, callValue)
}
}
default:
}
}
return
}
// XXX: May also need to taint the receiver
//
// TaintFunction tries to run taint analysis on the functionBody
// The initial taints are specified in the
// returns the indices of the tainted return values
func TaintFunction(context *Context, functionBody *ssa.Function, entryPoints []ssa.Value, callGraph *callgraph.Graph,
valueFieldMap map[ssa.Value]*FieldSet,
callStack *CallStack) (end bool, taintedParams []int, taintedRets []int) {
log.Printf("Stack %s\n", *callStack)
funcCall := FunctionCall{
FunctionName: functionBody.String(),
TaintSource: fmt.Sprint(entryPoints),
}
if callStack.Contain(funcCall) {
log.Printf("Recursive taint detected, directly return %s\n", funcCall)
return false, []int{}, []int{}
} else {
callStack.Push(funcCall)
defer callStack.Pop()
}
taintedSet := make(map[ssa.Value]bool)
for _, entryPoint := range entryPoints {
taintedSet[entryPoint] = true
}
taintedParamIndexSet := NewSet[int]() // used to store param index for return
taintedReturnIndexSet := NewSet[int]() // used to store return index for return
// cache
// when we finish tainting all the referrers of a value, no need to taint again
propogatedSet := make(map[ssa.Value]bool)
// loop until there is no new change
for {
changed := false
for taintedValue := range taintedSet {
if _, ok := propogatedSet[taintedValue]; ok {
continue
}
referrers := taintedValue.Referrers()
if referrers == nil {
log.Printf("%s: %s referrer not defined\n", taintedValue.Name(), taintedValue.String())
propogatedSet[taintedValue] = true
continue
}
for _, instruction := range *referrers {
switch typedInst := instruction.(type) {
case ssa.Value:
switch typedValue := typedInst.(type) {
case *ssa.Alloc:
// skip
log.Panic("Alloc referred\n")
case *ssa.BinOp:
// propogate to the result
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Call:
// context aware
end, taintedArgs, taintedRets := ContextAwareFunctionAnalysis(context, taintedValue, typedValue, callGraph, taintedSet, valueFieldMap, callStack)
for _, taintedArg := range taintedArgs {
if _, ok := taintedSet[taintedArg]; !ok {
taintedSet[taintedArg] = true
changed = true
}
}
for _, taintedRet := range taintedRets {
if _, ok := taintedSet[taintedRet]; !ok {
log.Printf("Got tainted return value [%s]\n", taintedRet.Name())
taintedSet[taintedRet] = true
changed = true
} else {
log.Printf("Got tainted return value [%s], but already tainted\n", taintedRet.Name())
}
}
if end {
return true, taintedParamIndexSet.Items(), taintedReturnIndexSet.Items()
}
case *ssa.ChangeInterface:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.ChangeType:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Extract:
if _, ok := taintedSet[typedValue]; !ok {
taintedSet[typedValue] = true
changed = true
}
case *ssa.Field: