Add taint-tracking for encoding/hex

ql/src/semmle/go/frameworks/Stdlib.qll

@@ -23,6 +23,7 @@ import semmle.go.frameworks.stdlib.EncodingBase64
 import semmle.go.frameworks.stdlib.EncodingBinary
 import semmle.go.frameworks.stdlib.EncodingCsv
 import semmle.go.frameworks.stdlib.EncodingGob
+import semmle.go.frameworks.stdlib.EncodingHex
 import semmle.go.frameworks.stdlib.Path
 import semmle.go.frameworks.stdlib.PathFilepath
 import semmle.go.frameworks.stdlib.Reflect

ql/src/semmle/go/frameworks/stdlib/EncodingHex.qll

@@ -0,0 +1,51 @@
+/**
+ * Provides classes modeling security-relevant aspects of the `encoding/hex` package.
+ */
+
+import go
+
+/** Provides models of commonly used functions in the `encoding/hex` package. */
+module EncodingHex {
+  private class FunctionModels extends TaintTracking::FunctionModel {
+    FunctionInput inp;
+    FunctionOutput outp;
+
+    FunctionModels() {
+      // signature: func Decode(dst []byte, src []byte) (int, error)
+      hasQualifiedName("encoding/hex", "Decode") and
+      (inp.isParameter(1) and outp.isParameter(0))
+      or
+      // signature: func DecodeString(s string) ([]byte, error)
+      hasQualifiedName("encoding/hex", "DecodeString") and
+      (inp.isParameter(0) and outp.isResult(0))
+      or
+      // signature: func Dump(data []byte) string
+      hasQualifiedName("encoding/hex", "Dump") and
+      (inp.isParameter(0) and outp.isResult())
+      or
+      // signature: func Dumper(w io.Writer) io.WriteCloser
+      hasQualifiedName("encoding/hex", "Dumper") and
+      (inp.isResult() and outp.isParameter(0))
+      or
+      // signature: func Encode(dst []byte, src []byte) int
+      hasQualifiedName("encoding/hex", "Encode") and
+      (inp.isParameter(1) and outp.isParameter(0))
+      or
+      // signature: func EncodeToString(src []byte) string
+      hasQualifiedName("encoding/hex", "EncodeToString") and
+      (inp.isParameter(0) and outp.isResult())
+      or
+      // signature: func NewDecoder(r io.Reader) io.Reader
+      hasQualifiedName("encoding/hex", "NewDecoder") and
+      (inp.isParameter(0) and outp.isResult())
+      or
+      // signature: func NewEncoder(w io.Writer) io.Writer
+      hasQualifiedName("encoding/hex", "NewEncoder") and
+      (inp.isResult() and outp.isParameter(0))
+    }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = inp and output = outp
+    }
+  }
+}

ql/test/library-tests/semmle/go/frameworks/StdlibTaintFlow/EncodingHex.go

@@ -0,0 +1,105 @@
+// Code generated by https://github.com/gagliardetto/codebox. DO NOT EDIT.
+
+package main
+
+import (
+	"encoding/hex"
+	"io"
+)
+
+func TaintStepTest_EncodingHexDecode_B0I0O0(sourceCQL interface{}) interface{} {
+	fromByte656 := sourceCQL.([]byte)
+	var intoByte414 []byte
+	hex.Decode(intoByte414, fromByte656)
+	return intoByte414
+}
+
+func TaintStepTest_EncodingHexDecodeString_B0I0O0(sourceCQL interface{}) interface{} {
+	fromString518 := sourceCQL.(string)
+	intoByte650, _ := hex.DecodeString(fromString518)
+	return intoByte650
+}
+
+func TaintStepTest_EncodingHexDump_B0I0O0(sourceCQL interface{}) interface{} {
+	fromByte784 := sourceCQL.([]byte)
+	intoString957 := hex.Dump(fromByte784)
+	return intoString957
+}
+
+func TaintStepTest_EncodingHexDumper_B0I0O0(sourceCQL interface{}) interface{} {
+	fromWriteCloser520 := sourceCQL.(io.WriteCloser)
+	var intoWriter443 io.Writer
+	intermediateCQL := hex.Dumper(intoWriter443)
+	link(fromWriteCloser520, intermediateCQL)
+	return intoWriter443
+}
+
+func TaintStepTest_EncodingHexEncode_B0I0O0(sourceCQL interface{}) interface{} {
+	fromByte127 := sourceCQL.([]byte)
+	var intoByte483 []byte
+	hex.Encode(intoByte483, fromByte127)
+	return intoByte483
+}
+
+func TaintStepTest_EncodingHexEncodeToString_B0I0O0(sourceCQL interface{}) interface{} {
+	fromByte989 := sourceCQL.([]byte)
+	intoString982 := hex.EncodeToString(fromByte989)
+	return intoString982
+}
+
+func TaintStepTest_EncodingHexNewDecoder_B0I0O0(sourceCQL interface{}) interface{} {
+	fromReader417 := sourceCQL.(io.Reader)
+	intoReader584 := hex.NewDecoder(fromReader417)
+	return intoReader584
+}
+
+func TaintStepTest_EncodingHexNewEncoder_B0I0O0(sourceCQL interface{}) interface{} {
+	fromWriter991 := sourceCQL.(io.Writer)
+	var intoWriter881 io.Writer
+	intermediateCQL := hex.NewEncoder(intoWriter881)
+	link(fromWriter991, intermediateCQL)
+	return intoWriter881
+}
+
+func RunAllTaints_EncodingHex() {
+	{
+		source := newSource(0)
+		out := TaintStepTest_EncodingHexDecode_B0I0O0(source)
+		sink(0, out)
+	}
+	{
+		source := newSource(1)
+		out := TaintStepTest_EncodingHexDecodeString_B0I0O0(source)
+		sink(1, out)
+	}
+	{
+		source := newSource(2)
+		out := TaintStepTest_EncodingHexDump_B0I0O0(source)
+		sink(2, out)
+	}
+	{
+		source := newSource(3)
+		out := TaintStepTest_EncodingHexDumper_B0I0O0(source)
+		sink(3, out)
+	}
+	{
+		source := newSource(4)
+		out := TaintStepTest_EncodingHexEncode_B0I0O0(source)
+		sink(4, out)
+	}
+	{
+		source := newSource(5)
+		out := TaintStepTest_EncodingHexEncodeToString_B0I0O0(source)
+		sink(5, out)
+	}
+	{
+		source := newSource(6)
+		out := TaintStepTest_EncodingHexNewDecoder_B0I0O0(source)
+		sink(6, out)
+	}
+	{
+		source := newSource(7)
+		out := TaintStepTest_EncodingHexNewEncoder_B0I0O0(source)
+		sink(7, out)
+	}
+}