Additional helpers (#2359)

* add starts_with, ends_with helper functions

* add test cases, update dsl signatures

* change split_starts_with to line_starts_with

integration_tests/http/dsl-functions.yaml

@@ -81,6 +81,10 @@ requests:
         69: {{zlib("Hello")}}
         70: {{zlib_decode(hex_decode("789cf248cdc9c907040000ffff058c01f5"))}}
         71: {{hex_encode(aes_gcm("AES256Key-32Characters1234567890", "exampleplaintext"))}}
+        72: {{starts_with("Hello", "He")}}
+        73: {{ends_with("Hello", "lo")}}
+        74: {{line_starts_with("Hi\nHello", "He")}}
+        75: {{line_ends_with("Hello\nHi", "lo")}}
         
     extractors:
       - type: regex

v2/cmd/integration-test/http.go

@@ -256,7 +256,7 @@ func (h *httpDSLFunctions) Execute(filePath string) error {
 	}
 
 	totalExtracted := strings.Split(submatch[1], ",")
-	numberOfDslFunctions := 71
+	numberOfDslFunctions := 75
 	if len(totalExtracted) != numberOfDslFunctions {
 		return errors.New("incorrect number of results")
 	}

v2/pkg/operators/common/dsl/dsl.go

@@ -246,6 +246,64 @@ func init() {
 		"contains": makeDslFunction(2, func(args ...interface{}) (interface{}, error) {
 			return strings.Contains(types.ToString(args[0]), types.ToString(args[1])), nil
 		}),
+		"starts_with": makeDslWithOptionalArgsFunction(
+			"(str string, prefix ...string) bool",
+			func(args ...interface{}) (interface{}, error) {
+				if len(args) < 2 {
+					return nil, invalidDslFunctionError
+				}
+				for _, prefix := range args[1:] {
+					if strings.HasPrefix(types.ToString(args[0]), types.ToString(prefix)) {
+						return true, nil
+					}
+				}
+				return false, nil
+			},
+		),
+		"line_starts_with": makeDslWithOptionalArgsFunction(
+			"(str string, prefix ...string) bool", func(args ...interface{}) (interface{}, error) {
+				if len(args) < 2 {
+					return nil, invalidDslFunctionError
+				}
+				for _, line := range strings.Split(types.ToString(args[0]), "\n") {
+					for _, prefix := range args[1:] {
+						if strings.HasPrefix(line, types.ToString(prefix)) {
+							return true, nil
+						}
+					}
+				}
+				return false, nil
+			},
+		),
+		"ends_with": makeDslWithOptionalArgsFunction(
+			"(str string, suffix ...string) bool",
+			func(args ...interface{}) (interface{}, error) {
+				if len(args) < 2 {
+					return nil, invalidDslFunctionError
+				}
+				for _, suffix := range args[1:] {
+					if strings.HasSuffix(types.ToString(args[0]), types.ToString(suffix)) {
+						return true, nil
+					}
+				}
+				return false, nil
+			},
+		),
+		"line_ends_with": makeDslWithOptionalArgsFunction(
+			"(str string, suffix ...string) bool", func(args ...interface{}) (interface{}, error) {
+				if len(args) < 2 {
+					return nil, invalidDslFunctionError
+				}
+				for _, line := range strings.Split(types.ToString(args[0]), "\n") {
+					for _, suffix := range args[1:] {
+						if strings.HasSuffix(line, types.ToString(suffix)) {
+							return true, nil
+						}
+					}
+				}
+				return false, nil
+			},
+		),
 		"concat": makeDslWithOptionalArgsFunction(
 			"(args ...interface{}) string",
 			func(arguments ...interface{}) (interface{}, error) {

v2/pkg/operators/common/dsl/dsl_test.go

@@ -142,6 +142,7 @@ func TestGetPrintableDslFunctionSignatures(t *testing.T) {
 	contains(arg1, arg2 interface{}) interface{}
 	date_time(dateTimeFormat string, optionalUnixTime interface{}) string
 	dec_to_hex(arg1 interface{}) interface{}
+	ends_with(str string, suffix ...string) bool
 	generate_java_gadget(arg1, arg2, arg3 interface{}) interface{}
 	gzip(arg1 interface{}) interface{}
 	gzip_decode(arg1 interface{}) interface{}
@@ -152,6 +153,8 @@ func TestGetPrintableDslFunctionSignatures(t *testing.T) {
 	html_unescape(arg1 interface{}) interface{}
 	join(separator string, elements ...interface{}) string
 	len(arg1 interface{}) interface{}
+	line_ends_with(str string, suffix ...string) bool
+	line_starts_with(str string, prefix ...string) bool
 	md5(arg1 interface{}) interface{}
 	mmh3(arg1 interface{}) interface{}
 	print_debug(args ...interface{})
@@ -170,6 +173,7 @@ func TestGetPrintableDslFunctionSignatures(t *testing.T) {
 	reverse(arg1 interface{}) interface{}
 	sha1(arg1 interface{}) interface{}
 	sha256(arg1 interface{}) interface{}
+	starts_with(str string, prefix ...string) bool
 	to_lower(arg1 interface{}) interface{}
 	to_number(arg1 interface{}) interface{}
 	to_string(arg1 interface{}) interface{}
@@ -248,6 +252,10 @@ func TestDslExpressions(t *testing.T) {
 		`len("Hello")`:                                     float64(5),
 		`len(1234)`:                                        float64(4),
 		`contains("Hello", "lo")`:                          true,
+		`starts_with("Hello", "He")`:                       true,
+		`ends_with("Hello", "lo")`:                         true,
+		"line_starts_with('Hi\nHello', 'He')":              true, // back quotes do not support escape sequences
+		"line_ends_with('Hii\nHello', 'ii')":               true, // back quotes do not support escape sequences
 		`regex("H([a-z]+)o", "Hello")`:                     true,
 		`wait_for(1)`:                                      nil,
 		`print_debug(1+2, "Hello")`:                        nil,