code: func NewUsesWeakCryptography(id string, conf gosec.Config) (gosec.Rule, []ast.Node) {
  	calls := make(map[string][]string)
  	calls["crypto/des"] = []string{"NewCipher", "NewTripleDESCipher"}
  	calls["crypto/md5"] = []string{"New", "Sum"}
  	calls["crypto/sha1"] = []string{"New", "Sum"}
  	calls["crypto/rc4"] = []string{"NewCipher"}
  	rule := &usesWeakCryptography{
  		blacklist: calls,
  		MetaData: gosec.MetaData{
  			ID:         id,
  			Severity:   gosec.Medium,
  			Confidence: gosec.High,
  			What:       "Use of weak cryptographic primitive",
  		},
  	}
  	return rule, []ast.Node{(*ast.CallExpr)(nil)}
  }
docs: // NewUsesWeakCryptography detects uses of des.* md5.* or rc4.*