Move to stdlib and expand crypto/cypher package taint-tracking

Author: gagliardetto

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

@@ -14,6 +14,7 @@ import semmle.go.frameworks.stdlib.CompressLzw
 import semmle.go.frameworks.stdlib.CompressZlib
 import semmle.go.frameworks.stdlib.Fmt
 import semmle.go.frameworks.stdlib.Crypto
+import semmle.go.frameworks.stdlib.CryptoCipher
 import semmle.go.frameworks.stdlib.Mime
 import semmle.go.frameworks.stdlib.MimeMultipart
 import semmle.go.frameworks.stdlib.MimeQuotedprintable
@@ -509,15 +510,3 @@ module Log {
     override predicate mayReturnNormally() { none() }
   }
 }
-
-/** Provides models of some functions in the `crypto/cipher` package. */
-module CryptoCipher {
-  private class AeadOpenFunction extends TaintTracking::FunctionModel, Method {
-    AeadOpenFunction() { this.hasQualifiedName("crypto/cipher", "AEAD", "Open") }
-
-    override predicate hasTaintFlow(FunctionInput inp, FunctionOutput outp) {
-      inp.isParameter(2) and
-      outp.isResult(0)
-    }
-  }
-}

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

@@ -0,0 +1,38 @@
+/**
+ * Provides classes modeling security-relevant aspects of the `crypto/cipher` package.
+ */
+
+import go
+
+/** Provides models of commonly used functions in the `crypto/cipher` package. */
+module CryptoCipher {
+  private class MethodModels extends TaintTracking::FunctionModel, Method {
+    FunctionInput inp;
+    FunctionOutput outp;
+
+    MethodModels() {
+      // signature: func (StreamReader).Read(dst []byte) (n int, err error)
+      this.hasQualifiedName("crypto/cipher", "StreamReader", "Read") and
+      (inp.isReceiver() and outp.isParameter(0))
+      or
+      // signature: func (StreamWriter).Write(src []byte) (n int, err error)
+      this.hasQualifiedName("crypto/cipher", "StreamWriter", "Write") and
+      (inp.isParameter(0) and outp.isReceiver())
+      or
+      // signature: func (Block).Decrypt(dst []byte, src []byte)
+      this.implements("crypto/cipher", "Block", "Decrypt") and
+      (inp.isParameter(1) and outp.isParameter(0))
+      or
+      // signature: func (AEAD).Open(dst []byte, nonce []byte, ciphertext []byte, additionalData []byte) ([]byte, error)
+      this.implements("crypto/cipher", "AEAD", "Open") and
+      (
+        inp.isParameter(2) and
+        (outp.isParameter(0) or outp.isResult(0))
+      )
+    }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = inp and output = outp
+    }
+  }
+}