Add taint-tracking for encoding/xml

Author: gagliardetto

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

@@ -26,6 +26,7 @@ import semmle.go.frameworks.stdlib.EncodingGob
 import semmle.go.frameworks.stdlib.EncodingHex
 import semmle.go.frameworks.stdlib.EncodingJson
 import semmle.go.frameworks.stdlib.EncodingPem
+import semmle.go.frameworks.stdlib.EncodingXml
 import semmle.go.frameworks.stdlib.Path
 import semmle.go.frameworks.stdlib.PathFilepath
 import semmle.go.frameworks.stdlib.Reflect

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

@@ -0,0 +1,130 @@
+/**
+ * Provides classes modeling security-relevant aspects of the `encoding/xml` package.
+ */
+
+import go
+
+/** Provides models of commonly used functions in the `encoding/xml` package. */
+module EncodingXml {
+  private class FunctionModels extends TaintTracking::FunctionModel {
+    FunctionInput inp;
+    FunctionOutput outp;
+
+    FunctionModels() {
+      // signature: func CopyToken(t Token) Token
+      hasQualifiedName("encoding/xml", "CopyToken") and
+      (inp.isParameter(0) and outp.isResult())
+      or
+      // signature: func Escape(w io.Writer, s []byte)
+      hasQualifiedName("encoding/xml", "Escape") and
+      (inp.isParameter(1) and outp.isParameter(0))
+      or
+      // signature: func EscapeText(w io.Writer, s []byte) error
+      hasQualifiedName("encoding/xml", "EscapeText") and
+      (inp.isParameter(1) and outp.isParameter(0))
+      or
+      // signature: func Marshal(v interface{}) ([]byte, error)
+      hasQualifiedName("encoding/xml", "Marshal") and
+      (inp.isParameter(0) and outp.isResult(0))
+      or
+      // signature: func MarshalIndent(v interface{}, prefix string, indent string) ([]byte, error)
+      hasQualifiedName("encoding/xml", "MarshalIndent") and
+      (inp.isParameter(_) and outp.isResult(0))
+      or
+      // signature: func NewDecoder(r io.Reader) *Decoder
+      hasQualifiedName("encoding/xml", "NewDecoder") and
+      (inp.isParameter(0) and outp.isResult())
+      or
+      // signature: func NewEncoder(w io.Writer) *Encoder
+      hasQualifiedName("encoding/xml", "NewEncoder") and
+      (inp.isResult() and outp.isParameter(0))
+      or
+      // signature: func NewTokenDecoder(t TokenReader) *Decoder
+      hasQualifiedName("encoding/xml", "NewTokenDecoder") and
+      (inp.isParameter(0) and outp.isResult())
+      or
+      // signature: func Unmarshal(data []byte, v interface{}) error
+      hasQualifiedName("encoding/xml", "Unmarshal") and
+      (inp.isParameter(0) and outp.isParameter(1))
+    }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = inp and output = outp
+    }
+  }
+
+  private class MethodModels extends TaintTracking::FunctionModel, Method {
+    FunctionInput inp;
+    FunctionOutput outp;
+
+    MethodModels() {
+      // signature: func (CharData).Copy() CharData
+      this.hasQualifiedName("encoding/xml", "CharData", "Copy") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (Comment).Copy() Comment
+      this.hasQualifiedName("encoding/xml", "Comment", "Copy") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (*Decoder).Decode(v interface{}) error
+      this.hasQualifiedName("encoding/xml", "Decoder", "Decode") and
+      (inp.isReceiver() and outp.isParameter(0))
+      or
+      // signature: func (*Decoder).DecodeElement(v interface{}, start *StartElement) error
+      this.hasQualifiedName("encoding/xml", "Decoder", "DecodeElement") and
+      (inp.isReceiver() and outp.isParameter(0))
+      or
+      // signature: func (*Decoder).RawToken() (Token, error)
+      this.hasQualifiedName("encoding/xml", "Decoder", "RawToken") and
+      (inp.isReceiver() and outp.isResult(0))
+      or
+      // signature: func (*Decoder).Token() (Token, error)
+      this.hasQualifiedName("encoding/xml", "Decoder", "Token") and
+      (inp.isReceiver() and outp.isResult(0))
+      or
+      // signature: func (Directive).Copy() Directive
+      this.hasQualifiedName("encoding/xml", "Directive", "Copy") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (*Encoder).Encode(v interface{}) error
+      this.hasQualifiedName("encoding/xml", "Encoder", "Encode") and
+      (inp.isParameter(0) and outp.isReceiver())
+      or
+      // signature: func (*Encoder).EncodeElement(v interface{}, start StartElement) error
+      this.hasQualifiedName("encoding/xml", "Encoder", "EncodeElement") and
+      (inp.isParameter(0) and outp.isReceiver())
+      or
+      // signature: func (*Encoder).EncodeToken(t Token) error
+      this.hasQualifiedName("encoding/xml", "Encoder", "EncodeToken") and
+      (inp.isParameter(0) and outp.isReceiver())
+      or
+      // signature: func (*Encoder).Indent(prefix string, indent string)
+      this.hasQualifiedName("encoding/xml", "Encoder", "Indent") and
+      (inp.isParameter(_) and outp.isReceiver())
+      or
+      // signature: func (ProcInst).Copy() ProcInst
+      this.hasQualifiedName("encoding/xml", "ProcInst", "Copy") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (StartElement).Copy() StartElement
+      this.hasQualifiedName("encoding/xml", "StartElement", "Copy") and
+      (inp.isReceiver() and outp.isResult())
+      or
+      // signature: func (Marshaler).MarshalXML(e *Encoder, start StartElement) error
+      this.implements("encoding/xml", "Marshaler", "MarshalXML") and
+      (inp.isReceiver() and outp.isParameter(0))
+      or
+      // signature: func (TokenReader).Token() (Token, error)
+      this.implements("encoding/xml", "TokenReader", "Token") and
+      (inp.isReceiver() and outp.isResult(0))
+      or
+      // signature: func (Unmarshaler).UnmarshalXML(d *Decoder, start StartElement) error
+      this.implements("encoding/xml", "Unmarshaler", "UnmarshalXML") and
+      (inp.isParameter(0) and outp.isReceiver())
+    }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = inp and output = outp
+    }
+  }
+}