Add compress/zlib taint tracking

Author: gagliardetto

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

@@ -11,6 +11,7 @@ import semmle.go.frameworks.stdlib.CompressBzip2
 import semmle.go.frameworks.stdlib.CompressFlate
 import semmle.go.frameworks.stdlib.CompressGzip
 import semmle.go.frameworks.stdlib.CompressLzw
+import semmle.go.frameworks.stdlib.CompressZlib
 
 /** A `String()` method. */
 class StringMethod extends TaintTracking::FunctionModel, Method {

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

@@ -0,0 +1,62 @@
+/**
+ * Provides classes modeling security-relevant aspects of the `compress/zlib` package.
+ */
+
+import go
+
+/** Provides models of commonly used functions in the `compress/zlib` package. */
+module CompressZlib {
+  private class FunctionModels extends TaintTracking::FunctionModel {
+    FunctionInput inp;
+    FunctionOutput outp;
+
+    FunctionModels() {
+      // signature: func NewReader(r io.Reader) (io.ReadCloser, error)
+      hasQualifiedName("compress/zlib", "NewReader") and
+      (inp.isParameter(0) and outp.isResult(0))
+      or
+      // signature: func NewReaderDict(r io.Reader, dict []byte) (io.ReadCloser, error)
+      hasQualifiedName("compress/zlib", "NewReaderDict") and
+      (inp.isParameter(0) and outp.isResult(0))
+      or
+      // signature: func NewWriter(w io.Writer) *Writer
+      hasQualifiedName("compress/zlib", "NewWriter") and
+      (inp.isResult() and outp.isParameter(0))
+      or
+      // signature: func NewWriterLevel(w io.Writer, level int) (*Writer, error)
+      hasQualifiedName("compress/zlib", "NewWriterLevel") and
+      (inp.isResult(0) and outp.isParameter(0))
+      or
+      // signature: func NewWriterLevelDict(w io.Writer, level int, dict []byte) (*Writer, error)
+      hasQualifiedName("compress/zlib", "NewWriterLevelDict") and
+      (inp.isResult(0) and outp.isParameter(0))
+    }
+
+    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 (*Writer).Reset(w io.Writer)
+      this.hasQualifiedName("compress/zlib", "Writer", "Reset") and
+      (inp.isReceiver() and outp.isParameter(0))
+      or
+      // signature: func (*Writer).Write(p []byte) (n int, err error)
+      this.hasQualifiedName("compress/zlib", "Writer", "Write") and
+      (inp.isParameter(0) and outp.isReceiver())
+      or
+      // signature: func (Resetter).Reset(r io.Reader, dict []byte) error
+      this.implements("compress/zlib", "Resetter", "Reset") and
+      (inp.isParameter(0) and outp.isReceiver())
+    }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = inp and output = outp
+    }
+  }
+}