Files
img-proxy-url-generator/generator/url.go
2024-04-23 10:27:07 -04:00

87 lines
1.8 KiB
Go

package generator
import (
"encoding/hex"
"fmt"
"strings"
)
type Generator struct {
config Config
}
type Config struct {
Salt []byte
saltBin []byte
Key []byte
keyBin []byte
Host string
EncryptionKey *string
encryptionKeyBin []byte
PlainUrl bool
}
var PathPrefix string
func NewGenerator(config Config) (*Generator, error) {
var err error
gen := new(Generator)
gen.config = config
if gen.config.keyBin, err = hex.DecodeString(string(gen.config.Key)); err != nil {
return nil, err
}
if gen.config.saltBin, err = hex.DecodeString(string(gen.config.Salt)); err != nil {
return nil, err
}
if gen.config.EncryptionKey != nil && *gen.config.EncryptionKey != "" {
if gen.config.encryptionKeyBin, err = hex.DecodeString(*gen.config.EncryptionKey); err != nil {
return nil, fmt.Errorf("key expected to be hex-encoded string")
}
}
return gen, nil
}
func (g *Generator) GenerateUrl(file string, params []string, format Format) (string, error) {
if params == nil || len(params) == 0 || params[0] == "" {
params = []string{"raw:1"}
} else {
params = append(params, "sm:1")
}
if PathPrefix != "" {
file = PathPrefix + file
}
paramString := "/" + strings.Join(params, "/") + "/"
var url string
var err error
if g.config.PlainUrl {
url, _ = g.generatePlainUrl(file)
} else if g.config.encryptionKeyBin != nil {
url, err = g.generateBaseAesEncUrl([]byte(file))
} else {
url, _ = g.generateBase64Url([]byte(file))
}
if err != nil {
return "", err
}
path := fmt.Sprintf("%s%s", paramString, url)
if format != DEF {
path = path + "." + string(format)
}
signature := g.generateSignature(path)
return fmt.Sprintf("%s/%s%s", g.config.Host, signature, path), nil
}