Documentation
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Overview ¶
Package srpguard provides memguard-backed 2FA password handling for telegram/auth, keeping the plaintext password in locked, swap-protected memory that is wiped after the SRP answer is computed.
It addresses gotd/td#755: a Go string cannot be reliably zeroed, so the 2FA password may linger in memory longer than necessary. The helpers here return an auth.PasswordHashFunc that reads the password from a memguard buffer and destroys it before returning.
Usage with the high-level method:
buf := memguard.NewBufferFromBytes(secret) // takes ownership, wipes secret _, err := client.Auth().PasswordWith(ctx, srpguard.LockedBuffer(buf))
or with an encrypted memguard.Enclave:
_, err := client.Auth().PasswordWith(ctx, srpguard.Enclave(enclave))
This package isolates the memguard dependency from the core auth package.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Enclave ¶
func Enclave(enc *memguard.Enclave) auth.PasswordHashFunc
Enclave returns an auth.PasswordHashFunc that opens enc into a locked buffer, computes the SRP answer and destroys the buffer. enc itself remains valid and may be reused.
func LockedBuffer ¶
func LockedBuffer(buf *memguard.LockedBuffer) auth.PasswordHashFunc
LockedBuffer returns an auth.PasswordHashFunc that computes the SRP answer from a password kept in buf, destroying buf afterwards.
buf is consumed: it is destroyed once the returned function is called (or, if it is never called, the caller remains responsible for destroying it).
Example ¶
This example shows how to supply a 2FA password from protected memory instead of a Go string, so the plaintext is locked, never swapped to disk, and wiped after the SRP answer is computed.
package main
import (
"context"
"github.com/awnumar/memguard"
"github.com/gotd/td/telegram/auth"
"github.com/gotd/td/telegram/auth/srpguard"
)
func main() {
// secret is read from a prompt/keyring into a byte slice; memguard takes
// ownership of it and wipes the original.
secret := []byte("correct horse battery staple")
buf := memguard.NewBufferFromBytes(secret)
// client is obtained via telegramClient.Auth().
var client *auth.Client
_, _ = client.PasswordWith(context.Background(), srpguard.LockedBuffer(buf))
}
Output:
Types ¶
This section is empty.
Source Files