feat(client): control 2fa password

packages/client/src/methods/pasword/change-cloud-password.ts

@@ -0,0 +1,44 @@
+import { TelegramClient } from '../../client'
+import { MtCuteArgumentError } from '../../types'
+import { assertTypeIs } from '../../utils/type-assertion'
+import { computeSrpParams, computeNewPasswordHash } from '@mtcute/core'
+
+/**
+ * Change your 2FA password
+ *
+ * @param currentPassword  Current password as plaintext
+ * @param newPassword  New password as plaintext
+ * @param hint  Hint for the new password
+ * @internal
+ */
+export async function changeCloudPassword(
+    this: TelegramClient,
+    currentPassword: string,
+    newPassword: string,
+    hint?: string
+): Promise<void> {
+    const pwd = await this.call({ _: 'account.getPassword' })
+    if (!pwd.hasPassword)
+        throw new MtCuteArgumentError('Cloud password is not enabled')
+
+    const algo = pwd.newAlgo
+    assertTypeIs(
+        'account.getPassword',
+        algo,
+        'passwordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow'
+    )
+
+    const oldSrp = await computeSrpParams(this._crypto, pwd, currentPassword)
+    const newHash = await computeNewPasswordHash(this._crypto, algo, newPassword)
+
+    await this.call({
+        _: 'account.updatePasswordSettings',
+        password: oldSrp,
+        newSettings: {
+            _: 'account.passwordInputSettings',
+            newAlgo: algo,
+            newPasswordHash: newHash,
+            hint
+        }
+    })
+}

packages/client/src/methods/pasword/enable-cloud-password.ts

@@ -0,0 +1,49 @@
+import { TelegramClient } from '../../client'
+import { MtCuteArgumentError } from '../../types'
+import { assertTypeIs } from '../../utils/type-assertion'
+import { computeNewPasswordHash } from '@mtcute/core'
+
+/**
+ * Enable 2FA password on your account
+ *
+ * Note that if you pass `email`, `EmailUnconfirmedError` may be
+ * thrown, and you should use {@link verifyPasswordEmail},
+ * {@link resendPasswordEmail} or {@link cancelPasswordEmail},
+ * and the call this method again
+ *
+ * @param password  2FA password as plaintext
+ * @param hint  Hint for the new password
+ * @param email  Recovery email
+ * @internal
+ */
+export async function enableCloudPassword(
+    this: TelegramClient,
+    password: string,
+    hint?: string,
+    email?: string
+): Promise<void> {
+    const pwd = await this.call({ _: 'account.getPassword' })
+    if (pwd.hasPassword)
+        throw new MtCuteArgumentError('Cloud password is already enabled')
+
+    const algo = pwd.newAlgo
+    assertTypeIs(
+        'account.getPassword',
+        algo,
+        'passwordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow'
+    )
+
+    const newHash = await computeNewPasswordHash(this._crypto, algo, password)
+
+    await this.call({
+        _: 'account.updatePasswordSettings',
+        password: { _: 'inputCheckPasswordEmpty' },
+        newSettings: {
+            _: 'account.passwordInputSettings',
+            newAlgo: algo,
+            newPasswordHash: newHash,
+            hint,
+            email
+        }
+    })
+}

packages/client/src/methods/pasword/password-email.ts

@@ -0,0 +1,39 @@
+import { TelegramClient } from '../../client'
+
+/**
+ * Verify an email to use as 2FA recovery method
+ *
+ * @param code  Code which was sent via email
+ * @internal
+ */
+export async function verifyPasswordEmail(
+    this: TelegramClient,
+    code: string
+): Promise<void> {
+    await this.call({
+        _: 'account.confirmPasswordEmail',
+        code
+    })
+}
+
+/**
+ * Resend the code to verify an email to use as 2FA recovery method.
+ *
+ * @internal
+ */
+export async function resendPasswordEmail(this: TelegramClient): Promise<void> {
+    await this.call({
+        _: 'account.resendPasswordEmail'
+    })
+}
+
+/**
+ * Cancel the code that was sent to verify an email to use as 2FA recovery method
+ *
+ * @internal
+ */
+export async function cancelPasswordEmail(this: TelegramClient): Promise<void> {
+    await this.call({
+        _: 'account.cancelPasswordEmail'
+    })
+}

packages/client/src/methods/pasword/remove-cloud-password.ts

@@ -0,0 +1,31 @@
+import { TelegramClient } from '../../client'
+import { MtCuteArgumentError } from '../../types'
+import { computeSrpParams } from '@mtcute/core'
+
+/**
+ * Remove 2FA password from your account
+ *
+ * @param password  2FA password as plaintext
+ * @internal
+ */
+export async function removeCloudPassword(
+    this: TelegramClient,
+    password: string,
+): Promise<void> {
+    const pwd = await this.call({ _: 'account.getPassword' })
+    if (!pwd.hasPassword)
+        throw new MtCuteArgumentError('Cloud password is not enabled')
+
+    const oldSrp = await computeSrpParams(this._crypto, pwd, password)
+
+    await this.call({
+        _: 'account.updatePasswordSettings',
+        password: oldSrp,
+        newSettings: {
+            _: 'account.passwordInputSettings',
+            newAlgo: { _: 'passwordKdfAlgoUnknown' },
+            newPasswordHash: Buffer.alloc(0),
+            hint: ''
+        }
+    })
+}

packages/core/src/utils/crypto/password.ts

@@ -4,6 +4,47 @@ import { bigIntToBuffer, bufferToBigInt } from '../bigint-utils'
 import bigInt from 'big-integer'
 import { randomBytes, xorBuffer } from '../buffer-utils'
 
+export async function computePasswordHash(
+    crypto: ICryptoProvider,
+    password: Buffer,
+    salt1: Buffer,
+    salt2: Buffer
+): Promise<Buffer> {
+    // https://core.telegram.org/api/srp#checking-the-password-with-srp
+    const SH = (data: Buffer, salt: Buffer) =>
+        crypto.sha256(Buffer.concat([salt, data, salt]))
+    const PH1 = async (pwd: Buffer, salt1: Buffer, salt2: Buffer) =>
+        SH(await SH(pwd, salt1), salt2)
+    const PH2 = async (pwd: Buffer, salt1: Buffer, salt2: Buffer) =>
+        SH(
+            await crypto.pbkdf2(await PH1(pwd, salt1, salt2), salt1, 100000),
+            salt2
+        )
+
+    return PH2(password, salt1, salt2)
+}
+
+export async function computeNewPasswordHash(
+    crypto: ICryptoProvider,
+    algo: tl.RawPasswordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow,
+    password: string
+): Promise<Buffer> {
+    (algo as tl.Mutable<typeof algo>).salt1 = Buffer.concat([algo.salt1, randomBytes(32)])
+
+    const _x = await computePasswordHash(
+        crypto,
+        Buffer.from(password),
+        algo.salt1,
+        algo.salt2
+    )
+
+    const g = bigInt(algo.g)
+    const p = bufferToBigInt(algo.p)
+    const x = bufferToBigInt(_x)
+
+    return bigIntToBuffer(g.modPow(x, p), 256)
+}
+
 export async function computeSrpParams(
     crypto: ICryptoProvider,
     request: tl.account.RawPassword,
@@ -20,18 +61,6 @@ export async function computeSrpParams(
 
     const algo = request.currentAlgo
 
-    // https://core.telegram.org/api/srp#checking-the-password-with-srp
-    const H = (data: Buffer) => crypto.sha256(data)
-    const SH = (data: Buffer, salt: Buffer) =>
-        H(Buffer.concat([salt, data, salt]))
-    const PH1 = async (pwd: Buffer, salt1: Buffer, salt2: Buffer) =>
-        SH(await SH(pwd, salt1), salt2)
-    const PH2 = async (pwd: Buffer, salt1: Buffer, salt2: Buffer) =>
-        SH(
-            await crypto.pbkdf2(await PH1(pwd, salt1, salt2), salt1, 100000),
-            salt2
-        )
-
     // here and after: underscored variables are buffers, non-underscored are bigInts
 
     const g = bigInt(algo.g)
@@ -43,11 +72,18 @@ export async function computeSrpParams(
     const gA = g.modPow(a, p)
     const _gA = bigIntToBuffer(gA, 256)
 
+    const H = (data: Buffer) => crypto.sha256(data)
+
     const [_k, _u, _x] = await Promise.all([
         // maybe, just maybe this will be a bit faster with some crypto providers
-        /* k = */ H(Buffer.concat([algo.p, _g])),
-        /* u = */ H(Buffer.concat([_gA, request.srpB!])),
-        /* x = */ PH2(Buffer.from(password), algo.salt1, algo.salt2),
+        /* k = */ crypto.sha256(Buffer.concat([algo.p, _g])),
+        /* u = */ crypto.sha256(Buffer.concat([_gA, request.srpB!])),
+        /* x = */ computePasswordHash(
+            crypto,
+            Buffer.from(password),
+            algo.salt1,
+            algo.salt2
+        ),
     ])
     const k = bufferToBigInt(_k)
     const u = bufferToBigInt(_u)