kafka/internal/engines/duckduckgo.go
Franz Kafka b3e3123612 security: fix build errors, add honest Google UA, sanitize error msgs
- Fix config validation: upstream URLs allow private IPs (self-hosted)
- Fix util.SafeURLScheme to return parsed URL
- Replace spoofed GSA User-Agent with honest Kafka UA
- Sanitize all engine error messages (strip response bodies)
- Replace unused body reads with io.Copy(io.Discard, ...) for reuse
- Fix pre-existing braveapi_test using wrong struct type
- Fix ratelimit test reference to limiter variable
- Update ratelimit tests for new trusted proxy behavior
2026-03-22 16:27:49 +00:00

103 lines
3.2 KiB
Go

// kafka — a privacy-respecting metasearch engine
// Copyright (C) 2026-present metamorphosis-dev
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package engines
import (
"context"
"errors"
"fmt"
"io"
"net/http"
"net/url"
"strings"
"github.com/metamorphosis-dev/kafka/internal/contracts"
)
// DuckDuckGoEngine searches DuckDuckGo's Lite/HTML endpoint.
// DuckDuckGo Lite returns a simple HTML page that can be scraped for results.
type DuckDuckGoEngine struct {
client *http.Client
}
func (e *DuckDuckGoEngine) Name() string { return "duckduckgo" }
func (e *DuckDuckGoEngine) Search(ctx context.Context, req contracts.SearchRequest) (contracts.SearchResponse, error) {
if strings.TrimSpace(req.Query) == "" {
return contracts.SearchResponse{Query: req.Query}, nil
}
if e == nil || e.client == nil {
return contracts.SearchResponse{}, errors.New("duckduckgo engine not initialized")
}
endpoint := fmt.Sprintf(
"https://lite.duckduckgo.com/lite/?q=%s&kl=%s",
url.QueryEscape(req.Query),
duckduckgoRegion(req.Language),
)
httpReq, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
if err != nil {
return contracts.SearchResponse{}, err
}
httpReq.Header.Set("User-Agent", "kafka/0.1 (compatible; +https://git.ashisgreat.xyz/penal-colony/gosearch)")
resp, err := e.client.Do(httpReq)
if err != nil {
return contracts.SearchResponse{}, err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
io.Copy(io.Discard, io.LimitReader(resp.Body, 4096))
return contracts.SearchResponse{}, fmt.Errorf("duckduckgo upstream error: status %d", resp.StatusCode)
}
results, err := parseDuckDuckGoHTML(resp.Body)
if err != nil {
return contracts.SearchResponse{}, err
}
return contracts.SearchResponse{
Query: req.Query,
NumberOfResults: len(results),
Results: results,
Answers: []map[string]any{},
Corrections: []string{},
Infoboxes: []map[string]any{},
Suggestions: []string{},
UnresponsiveEngines: [][2]string{},
}, nil
}
// duckduckgoRegion maps language codes to DDG region parameters.
func duckduckgoRegion(lang string) string {
lang = strings.ToLower(strings.TrimSpace(lang))
if lang == "" || lang == "auto" {
return "us-en"
}
langCode := strings.SplitN(lang, "-", 2)[0]
regionMap := map[string]string{
"en": "us-en", "de": "de-de", "fr": "fr-fr", "es": "es-es",
"pt": "br-pt", "ru": "ru-ru", "ja": "jp-jp", "zh": "cn-zh",
"ko": "kr-kr", "it": "it-it", "nl": "nl-nl", "pl": "pl-pl",
}
if region, ok := regionMap[langCode]; ok {
return region
}
return "wt-wt"
}