/usr/share/gocode/src/strk.kbt.io/projects/go/libravatar/libravatar.go is in golang-strk.kbt-projects-go-libravatar-dev 0.0~git20161111.0.d628b68-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 | // Copyright 2016 by Sandro Santilli <strk@kbt.io>
// Use of this source code is governed by a MIT
// license that can be found in the LICENSE file.
// Implements support for federated avatars lookup.
// See https://wiki.libravatar.org/api/
package libravatar // import "strk.kbt.io/projects/go/libravatar"
import (
"crypto/md5"
"crypto/sha256"
"fmt"
"math/rand"
"net"
"net/mail"
"net/url"
"strings"
"time"
)
// Default images (to be used as defaultURL)
const (
// Do not load any image if none is associated with the email
// hash, instead return an HTTP 404 (File Not Found) response
HTTP404 = "404"
// (mystery-man) a simple, cartoon-style silhouetted outline of
// a person (does not vary by email hash)
MysteryMan = "mm"
// a geometric pattern based on an email hash
IdentIcon = "identicon"
// a generated 'monster' with different colors, faces, etc
MonsterID = "monsterid"
// generated faces with differing features and backgrounds
Wavatar = "wavatar"
// awesome generated, 8-bit arcade-style pixelated faces
Retro = "retro"
)
var (
// DefaultLibravatar is a default Libravatar object,
// enabling object-less function calls
DefaultLibravatar = New()
)
/* This should be moved in its own file */
type cacheKey struct {
service string
domain string
}
type cacheValue struct {
target string
checkedAt time.Time
}
// Libravatar is an opaque structure holding service configuration
type Libravatar struct {
defURL string // default url
picSize int // picture size
fallbackHost string // default fallback URL
secureFallbackHost string // default fallback URL for secure connections
useHTTPS bool
nameCache map[cacheKey]cacheValue
nameCacheDuration time.Duration
minSize uint // smallest image dimension allowed
maxSize uint // largest image dimension allowed
size uint // what dimension should be used
serviceBase string // SRV record to be queried for federation
secureServiceBase string // SRV record to be queried for federation with secure servers
}
// New instanciates a new Libravatar object (handle)
func New() *Libravatar {
// According to https://wiki.libravatar.org/running_your_own/
// the time-to-live (cache expiry) should be set to at least 1 day.
return &Libravatar{
fallbackHost: `cdn.libravatar.org`,
secureFallbackHost: `seccdn.libravatar.org`,
minSize: 1,
maxSize: 512,
size: 0, // unset, defaults to 80
serviceBase: `avatars`,
secureServiceBase: `avatars-sec`,
nameCache: make(map[cacheKey]cacheValue),
nameCacheDuration: 24 * time.Hour,
}
}
// SetFallbackHost sets the hostname for fallbacks in case no avatar
// service is defined for a domain
func (v *Libravatar) SetFallbackHost(host string) {
v.fallbackHost = host
}
// SetSecureFallbackHost sets the hostname for fallbacks in case no
// avatar service is defined for a domain, when requiring secure domains
func (v *Libravatar) SetSecureFallbackHost(host string) {
v.secureFallbackHost = host
}
// SetUseHTTPS sets flag requesting use of https for fetching avatars
func (v *Libravatar) SetUseHTTPS(use bool) {
v.useHTTPS = use
}
// SetAvatarSize sets avatars image dimension (0 for default)
func (v *Libravatar) SetAvatarSize(size uint) {
v.size = size
}
// generate hash, either with email address or OpenID
func (v *Libravatar) genHash(email *mail.Address, openid *url.URL) string {
if email != nil {
email.Address = strings.ToLower(strings.TrimSpace(email.Address))
sum := md5.Sum([]byte(email.Address))
return fmt.Sprintf("%x", sum)
} else if openid != nil {
openid.Scheme = strings.ToLower(openid.Scheme)
openid.Host = strings.ToLower(openid.Host)
sum := sha256.Sum256([]byte(openid.String()))
return fmt.Sprintf("%x", sum)
}
// panic, because this should not be reachable
panic("Neither Email or OpenID set")
}
// Gets domain out of email or openid (for openid to be parsed, email has to be nil)
func (v *Libravatar) getDomain(email *mail.Address, openid *url.URL) string {
if email != nil {
u, err := url.Parse("//" + email.Address)
if err != nil {
if v.useHTTPS && v.secureFallbackHost != "" {
return v.secureFallbackHost
}
return v.fallbackHost
}
return u.Host
} else if openid != nil {
return openid.Host
}
// panic, because this should not be reachable
panic("Neither Email or OpenID set")
}
// Processes email or openid (for openid to be processed, email has to be nil)
func (v *Libravatar) process(email *mail.Address, openid *url.URL) (string, error) {
URL, err := v.baseURL(email, openid)
if err != nil {
return "", err
}
res := fmt.Sprintf("%s/avatar/%s", URL, v.genHash(email, openid))
values := make(url.Values)
if v.defURL != "" {
values.Add("d", v.defURL)
}
if v.size > 0 {
values.Add("s", fmt.Sprintf("%d", v.size))
}
if len(values) > 0 {
return fmt.Sprintf("%s?%s", res, values.Encode()), nil
}
return res, nil
}
// Finds or defaults a URL for Federation (for openid to be used, email has to be nil)
func (v *Libravatar) baseURL(email *mail.Address, openid *url.URL) (string, error) {
var service, protocol, domain string
if v.useHTTPS {
protocol = "https://"
service = v.secureServiceBase
domain = v.secureFallbackHost
} else {
protocol = "http://"
service = v.serviceBase
domain = v.fallbackHost
}
host := v.getDomain(email, openid)
key := cacheKey{service, host}
now := time.Now()
val, found := v.nameCache[key]
if found && now.Sub(val.checkedAt) <= v.nameCacheDuration {
return protocol + val.target, nil
}
_, addrs, err := net.LookupSRV(service, "tcp", host)
if err != nil && err.(*net.DNSError).IsTimeout {
return "", err
}
if len(addrs) == 1 {
// select only record, if only one is available
domain = strings.TrimSuffix(addrs[0].Target, ".")
} else if len(addrs) > 1 {
// Select first record according to RFC2782 weight
// ordering algorithm (page 3)
type record struct {
srv *net.SRV
weight uint16
}
var (
totalWeight uint16
records []record
topPriority = addrs[0].Priority
topRecord *net.SRV
)
for _, rr := range addrs {
if rr.Priority > topPriority {
continue
} else if rr.Priority < topPriority {
// won't happen, because net sorts
// by priority, but just in case
totalWeight = 0
records = nil
topPriority = rr.Priority
}
totalWeight += rr.Weight
if rr.Weight > 0 {
records = append(records, record{rr, totalWeight})
} else if rr.Weight == 0 {
records = append([]record{record{srv: rr, weight: totalWeight}}, records...)
}
}
if len(records) == 1 {
topRecord = records[0].srv
} else {
randnum := uint16(rand.Intn(int(totalWeight)))
for _, rr := range records {
if rr.weight >= randnum {
topRecord = rr.srv
break
}
}
}
domain = fmt.Sprintf("%s:%d", topRecord.Target, topRecord.Port)
}
v.nameCache[key] = cacheValue{checkedAt: now, target: domain}
return protocol + domain, nil
}
// FromEmail returns the url of the avatar for the given email
func (v *Libravatar) FromEmail(email string) (string, error) {
addr, err := mail.ParseAddress(email)
if err != nil {
return "", err
}
link, err := v.process(addr, nil)
if err != nil {
return "", err
}
return link, nil
}
// FromEmail is the object-less call to DefaultLibravatar for an email adders
func FromEmail(email string) (string, error) {
return DefaultLibravatar.FromEmail(email)
}
// FromURL returns the url of the avatar for the given url (typically
// for OpenID)
func (v *Libravatar) FromURL(openid string) (string, error) {
ourl, err := url.Parse(openid)
if err != nil {
return "", err
}
if !ourl.IsAbs() {
return "", fmt.Errorf("Is not an absolute URL")
} else if ourl.Scheme != "http" && ourl.Scheme != "https" {
return "", fmt.Errorf("Invalid protocol: %s", ourl.Scheme)
}
link, err := v.process(nil, ourl)
if err != nil {
return "", err
}
return link, nil
}
// FromURL is the object-less call to DefaultLibravatar for a URL
func FromURL(openid string) (string, error) {
return DefaultLibravatar.FromURL(openid)
}
|