1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
// mirror files from upstream NVD source
package nvdmirror
import (
"fmt"
"github.com/rs/zerolog/log"
"io"
"net/http"
"net/url"
"os"
"path/filepath"
"time"
)
// default user agent (FIXME: make configurable)
var defaultUserAgent = "cvez/0.1.0"
// Sync() configuration.
type SyncConfig struct {
// CVE 1.1 Base URL. The full meta and JSON URLs are constructed by
// appending the file name to this base.
Cve11BaseUrl string
// CPE 1.0 base URL. The full meta and JSON URLs are constructed by
// appending the file name to this base.
Cpe10MatchBaseUrl string
// CPE 2.3 dictionary URL.
Cpe23DictUrl string
// User agent string. Set to "" for default user agent string.
UserAgent string
// Maximum number of idle connections.
MaxIdleConns int
// Idle connection timeout.
IdleConnTimeout time.Duration
}
// Get user agent string.
func (me SyncConfig) GetUserAgent() string {
if len(me.UserAgent) > 0 {
return me.UserAgent
} else {
return defaultUserAgent
}
}
// NVD URLs
var DefaultConfig = SyncConfig {
Cve11BaseUrl: "https://nvd.nist.gov/feeds/json/cve/1.1",
Cpe10MatchBaseUrl: "https://nvd.nist.gov/feeds/json/cpematch/1.0",
Cpe23DictUrl: "https://nvd.nist.gov/feeds/xml/cpe/dictionary/official-cpe-dictionary_v2.3.xml.gz",
}
var extraFiles = []string {
"nvdcve-1.1-modified",
"nvdcve-1.1-recent",
}
// fetch result
type fetchResult struct {
src string // source URL
err error // fetch result
modified bool // was the result modified?
lastModified string // last modified response header
etag string // etag response header
}
// base CVE year
const baseYear = 2002
func fetch(ch chan fetchResult, config SyncConfig, cache Cache, client *http.Client, srcUrl string, dstDir string) {
// parse source url
src, err := url.Parse(srcUrl)
if err != nil {
ch <- fetchResult { src: srcUrl, err: err }
return
}
// build destination path
path := filepath.Join(dstDir, filepath.Base(src.Path))
log.Debug().Str("url", srcUrl).Str("path", path).Send()
// create temporary output file
f, err := os.CreateTemp(filepath.Dir(path), "")
if err != nil {
ch <- fetchResult { src: srcUrl, err: err }
return
}
defer os.Remove(f.Name())
// create request
req, err := http.NewRequest("GET", srcUrl, nil)
if err != nil {
ch <- fetchResult { src: srcUrl, err: err }
return
}
// add request headers
req.Header.Add("user-agent", config.GetUserAgent())
if headers, ok := cache.Get(srcUrl); ok {
for k, v := range(headers) {
req.Header.Add(k, v)
}
}
// send request
resp, err := client.Do(req)
if err != nil {
ch <- fetchResult { src: srcUrl, err: err }
return
}
defer resp.Body.Close()
switch resp.StatusCode {
case 200:
// copy body to result
if size, err := io.Copy(f, resp.Body); err != nil {
// copy failed
ch <- fetchResult { src: srcUrl, err: err, modified: false }
} else if err = os.Rename(f.Name(), path); err != nil {
// rename failed
ch <- fetchResult { src: srcUrl, err: err, modified: false }
} else {
log.Debug().Str("url", srcUrl).Int64("size", size).Send()
ch <- fetchResult {
src: srcUrl,
modified: true,
lastModified: resp.Header.Get("last-modified"),
etag: resp.Header.Get("etag"),
}
}
case 304:
ch <- fetchResult { src: srcUrl, modified: false }
default:
code := resp.StatusCode
err := fmt.Errorf("%d: %s", code, http.StatusText(code))
ch <- fetchResult { src: srcUrl, err: err }
}
}
func Sync(config SyncConfig, cache Cache, dstDir string) error {
log.Debug().Str("dstDir", dstDir).Msg("Sync")
// create fetch result channel
ch := make(chan fetchResult)
// create shared transport and client
tr := &http.Transport{
MaxIdleConns: config.MaxIdleConns,
IdleConnTimeout: config.IdleConnTimeout,
}
client := &http.Client{Transport: tr}
// calculate total number of years
numYears := time.Now().Year() - baseYear + 1
// fetch cve feed metas
for year := baseYear; year < baseYear + numYears; year++ {
// build url
url := fmt.Sprintf("%s/nvdcve-1.1-%04d.meta", config.Cve11BaseUrl, year)
log.Debug().Int("year", year).Str("url", url).Send()
go fetch(ch, config, cache, client, url, dstDir)
}
// fetch cve extra file metas
for _, s := range(extraFiles) {
url := fmt.Sprintf("%s/%s.meta", config.Cve11BaseUrl, s)
log.Debug().Str("file", s).Str("url", url).Send()
go fetch(ch, config, cache, client, url, dstDir)
}
// read results
for i := 0; i < numYears + len(extraFiles); i++ {
if r := <-ch; r.err != nil {
log.Error().Str("url", r.src).Err(r.err).Send()
// FIXME: errs = append(errs, r)
} else {
log.Info().Str("url", r.src).Str("etag", r.etag).Msg("ok")
if r.modified {
// build request headers
headers := map[string]string {
"if-none-match": r.etag,
"if-modified-since": r.lastModified,
}
// save headers to cache
if err := cache.Set(r.src, headers); err != nil {
log.Error().Str("url", r.src).Err(r.err).Msg("Set")
return err
}
}
}
}
// TODO: fetch cpe dictionary
// TODO: fetch cpematch
// "nvdcpematch-1.0.{meta,json}",
// return success
return nil
}
|
