Add taint-tracking for mime/multipart

Author: gagliardetto

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

@@ -13,6 +13,7 @@ import semmle.go.frameworks.stdlib.CompressGzip
 import semmle.go.frameworks.stdlib.CompressLzw
 import semmle.go.frameworks.stdlib.CompressZlib
 import semmle.go.frameworks.stdlib.Mime
+import semmle.go.frameworks.stdlib.MimeMultipart
 import semmle.go.frameworks.stdlib.Path
 import semmle.go.frameworks.stdlib.PathFilepath
 

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

@@ -0,0 +1,74 @@
+/**
+ * Provides classes modeling security-relevant aspects of the `mime/multipart` package.
+ */
+
+import go
+
+/** Provides models of commonly used functions in the `mime/multipart` package. */
+module MimeMultipart {
+  private class FunctionModels extends TaintTracking::FunctionModel {
+    FunctionInput inp;
+    FunctionOutput outp;
+
+    FunctionModels() {
+      // signature: func NewReader(r io.Reader, boundary string) *Reader
+      hasQualifiedName("mime/multipart", "NewReader") and
+      (inp.isParameter(0) and outp.isResult())
+      or
+      // signature: func NewWriter(w io.Writer) *Writer
+      hasQualifiedName("mime/multipart", "NewWriter") and
+      (inp.isResult() 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 (*FileHeader).Open() (File, error)
+      this.hasQualifiedName("mime/multipart", "FileHeader", "Open") and
+      (inp.isReceiver() and outp.isResult(0))
+      or
+      // signature: func (*Part).Read(d []byte) (n int, err error)
+      this.hasQualifiedName("mime/multipart", "Part", "Read") and
+      (inp.isReceiver() and outp.isParameter(0))
+      or
+      // signature: func (*Reader).NextPart() (*Part, error)
+      this.hasQualifiedName("mime/multipart", "Reader", "NextPart") and
+      (inp.isReceiver() and outp.isResult(0))
+      or
+      // signature: func (*Reader).NextRawPart() (*Part, error)
+      this.hasQualifiedName("mime/multipart", "Reader", "NextRawPart") and
+      (inp.isReceiver() and outp.isResult(0))
+      or
+      // signature: func (*Reader).ReadForm(maxMemory int64) (*Form, error)
+      this.hasQualifiedName("mime/multipart", "Reader", "ReadForm") and
+      (inp.isReceiver() and outp.isResult(0))
+      or
+      // signature: func (*Writer).CreateFormField(fieldname string) (io.Writer, error)
+      this.hasQualifiedName("mime/multipart", "Writer", "CreateFormField") and
+      (inp.isResult(0) and outp.isReceiver())
+      or
+      // signature: func (*Writer).CreateFormFile(fieldname string, filename string) (io.Writer, error)
+      this.hasQualifiedName("mime/multipart", "Writer", "CreateFormFile") and
+      (inp.isResult(0) and outp.isReceiver())
+      or
+      // signature: func (*Writer).CreatePart(header net/textproto.MIMEHeader) (io.Writer, error)
+      this.hasQualifiedName("mime/multipart", "Writer", "CreatePart") and
+      (inp.isResult(0) and outp.isReceiver())
+      or
+      // signature: func (*Writer).WriteField(fieldname string, value string) error
+      this.hasQualifiedName("mime/multipart", "Writer", "WriteField") and
+      (inp.isParameter(_) and outp.isReceiver())
+    }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = inp and output = outp
+    }
+  }
+}