126 lines
3.3 KiB
Go
126 lines
3.3 KiB
Go
package localreset
|
|
|
|
import (
|
|
"bufio"
|
|
"context"
|
|
"net"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
type Client struct {
|
|
conn net.Conn
|
|
reader *bufio.Reader
|
|
nonce string
|
|
methods []Method
|
|
recoveryAvailable bool
|
|
stage int
|
|
stop func() bool
|
|
mu sync.Mutex
|
|
once sync.Once
|
|
}
|
|
|
|
// Begin 只接受已通过 Dial 校验身份的连接；调用过程不会通过参数或文件传递密码。
|
|
func Begin(ctx context.Context, conn net.Conn) (*Client, error) {
|
|
if conn == nil {
|
|
return nil, ErrUnavailable
|
|
}
|
|
deadline := time.Now().Add(SessionTimeout)
|
|
if requested, ok := ctx.Deadline(); ok && requested.Before(deadline) {
|
|
deadline = requested
|
|
}
|
|
if err := conn.SetDeadline(deadline); err != nil {
|
|
_ = conn.Close()
|
|
return nil, err
|
|
}
|
|
client := &Client{conn: conn, reader: bufio.NewReaderSize(conn, MaxFrameSize+1)}
|
|
client.stop = context.AfterFunc(ctx, func() { _ = conn.Close() })
|
|
var response Response
|
|
if err := readFrame(client.reader, &response); err != nil || !validChallenge(response) ||
|
|
len(response.Methods) == 0 || len(response.Methods) > 8 || response.RecoveryPage != nil || response.Inspection != nil || response.InspectionPart != nil {
|
|
_ = client.Close()
|
|
return nil, ErrProtocol
|
|
}
|
|
client.nonce = response.Nonce
|
|
client.methods = response.Methods
|
|
client.recoveryAvailable = response.RecoveryAvailable
|
|
return client, nil
|
|
}
|
|
|
|
func (c *Client) Methods() []Method { return append([]Method(nil), c.methods...) }
|
|
func (c *Client) Select(method string) error {
|
|
return c.exchange(Request{Action: "select", Method: method}, 0)
|
|
}
|
|
func (c *Client) Verify(code string) error {
|
|
return c.exchange(Request{Action: "verify", Code: code}, 1)
|
|
}
|
|
func (c *Client) Reset(password string) error {
|
|
return c.exchange(Request{Action: "reset", Password: password}, 2)
|
|
}
|
|
|
|
func (c *Client) exchange(request Request, stage int) error {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.stage != stage {
|
|
_ = c.Close()
|
|
return ErrProtocol
|
|
}
|
|
request.Version, request.Nonce = Version, c.nonce
|
|
if !validRequest(request, c.nonce, request.Action) || writeFrame(c.conn, request) != nil {
|
|
c.stage = -1
|
|
_ = c.Close()
|
|
return ErrProtocol
|
|
}
|
|
var response Response
|
|
if err := readFrame(c.reader, &response); err != nil {
|
|
c.stage = -1
|
|
_ = c.Close()
|
|
return ErrProtocol
|
|
}
|
|
if response.RecoveryAvailable || response.RecoveryPage != nil || response.Inspection != nil || response.InspectionPart != nil {
|
|
c.stage = -1
|
|
_ = c.Close()
|
|
return ErrProtocol
|
|
}
|
|
if stage == 2 {
|
|
c.stage = -1
|
|
_ = c.Close()
|
|
if response.Version != Version || !response.OK || response.Code != "COMPLETE" ||
|
|
response.Nonce != "" || len(response.Methods) != 0 {
|
|
return ErrProtocol
|
|
}
|
|
return nil
|
|
}
|
|
if !validChallenge(response) || response.Nonce == c.nonce || len(response.Methods) != 0 {
|
|
c.stage = -1
|
|
_ = c.Close()
|
|
return ErrProtocol
|
|
}
|
|
c.nonce = response.Nonce
|
|
c.stage++
|
|
return nil
|
|
}
|
|
|
|
func validChallenge(response Response) bool {
|
|
if response.Version != Version || !response.OK || response.Code != "CHALLENGE" || len(response.Nonce) != 64 {
|
|
return false
|
|
}
|
|
for _, value := range response.Nonce {
|
|
if (value < '0' || value > '9') && (value < 'a' || value > 'f') {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func (c *Client) Close() error {
|
|
var err error
|
|
c.once.Do(func() {
|
|
if c.stop != nil {
|
|
c.stop()
|
|
}
|
|
err = c.conn.Close()
|
|
})
|
|
return err
|
|
}
|