go-mockid/mockid/api/common.go

76 lines
1.5 KiB
Go

package api
import (
"bytes"
"crypto/sha256"
"encoding/binary"
"encoding/json"
"errors"
"io"
"log"
"math/rand"
mathrand "math/rand"
"net/http"
)
// options are the things that we may need to know about a request to fulfill it properly
type options struct {
Key string `json:"key"`
KeyType string `json:"kty"`
Seed int64 `json:"-"`
SeedStr string `json:"seed"`
}
// this shananigans is only for testing and debug API stuff
func (o *options) nextReader() io.Reader {
if 0 == o.Seed {
return RandomReader
}
return rand.New(rand.NewSource(o.Seed))
}
func getOpts(r *http.Request) (*options, error) {
tok := make(map[string]interface{})
decoder := json.NewDecoder(r.Body)
err := decoder.Decode(&tok)
if nil != err && io.EOF != err {
log.Printf("json decode error: %s", err)
return nil, errors.New("Bad Request: invalid json body")
}
defer r.Body.Close()
var seed int64
seedStr, _ := tok["seed"].(string)
if "" != seedStr {
if len(seedStr) > 256 {
return nil, errors.New("Bad Request: base64 seed should be <256 characters (and is truncated to 64-bits anyway)")
}
b := sha256.Sum256([]byte(seedStr))
seed, _ = binary.ReadVarint(bytes.NewReader(b[0:8]))
}
key, _ := tok["key"].(string)
opts := &options{
Seed: seed,
Key: key,
}
var n int
if 0 != seed {
n = opts.nextReader().(*mathrand.Rand).Intn(2)
} else {
n = rand.Intn(2)
}
opts.KeyType, _ = tok["kty"].(string)
if "" == opts.KeyType {
if 0 == n {
opts.KeyType = "RSA"
} else {
opts.KeyType = "EC"
}
}
return opts, nil
}