Cipher is message encryption utility struct.encryptSideSiderandio.Reader Decrypt decrypts data from encrypted message using AES-IGE. DecryptFromBuffer decodes EncryptedMessage and decrypts it. Encrypt encrypts EncryptedMessageData using AES-IGE to given buffer. Rand returns random generator. decryptMessage decrypts data from encrypted message using AES-IGE. encryptMessage encrypts plaintext using AES-IGE.
Cipher : github.com/gotd/td/internal/mtproto.Cipher
func NewClientCipher(rand io.Reader) Cipher
func NewServerCipher(rand io.Reader) Cipher
EncryptedMessageData is stored in EncryptedMessage.EncryptedData. Message to encode to MessageDataWithPadding.
Needed to prevent unnecessary allocations in EncodeWithoutCopy.MessageDataLenint32MessageDataWithPadding[]byteMessageIDint64Saltint64SeqNoint32SessionIDint64 Data returns message data without hash. Decode implements bin.Decoder. DecodeWithoutCopy is like Decode, but MessageDataWithPadding references to given buffer instead of
copying. Encode implements bin.Encoder. EncodeWithoutCopy is like Encode, but tries to encode Message and uses only one buffer
to encode. If Message is nil, fallbacks to Encode.
*EncryptedMessageData : github.com/gotd/td/bin.Decoder
EncryptedMessageData : github.com/gotd/td/bin.Encoder
*EncryptedMessageData : github.com/gotd/td/bin.Object
func Cipher.Decrypt(k AuthKey, encrypted *EncryptedMessage) (*EncryptedMessageData, error)
func Cipher.DecryptFromBuffer(k AuthKey, buf *bin.Buffer) (*EncryptedMessageData, error)
func github.com/gotd/td/internal/mtproto.Cipher.DecryptFromBuffer(k AuthKey, buf *bin.Buffer) (*EncryptedMessageData, error)
func github.com/gotd/td/internal/mtproto.(*Conn).decryptMessage(b *bin.Buffer) (*EncryptedMessageData, error)
func Cipher.Encrypt(key AuthKey, data EncryptedMessageData, b *bin.Buffer) error
func github.com/gotd/td/internal/mtproto.Cipher.Encrypt(key AuthKey, data EncryptedMessageData, b *bin.Buffer) error
Package-Level Functions (total 55, in which 34 are exported)
CheckDH performs DH parameters check described in Telegram docs.
Client is expected to check whether p is a safe 2048-bit prime (meaning that both p and (p-1)/2 are prime,
and that 2^2047 < p < 2^2048), and that g generates a cyclic subgroup of prime order (p-1)/2, i.e.
is a quadratic residue mod p. Since g is always equal to 2, 3, 4, 5, 6 or 7, this is easily done using quadratic
reciprocity law, yielding a simple condition on p mod 4g — namely, p mod 8 = 7 for g = 2; p mod 3 = 2 for g = 3;
no extra condition for g = 4; p mod 5 = 1 or 4 for g = 5; p mod 24 = 19 or 23 for g = 6; and p mod 7 = 3,
5 or 6 for g = 7.
See https://core.telegram.org/mtproto/auth_key#presenting-proof-of-work-server-authentication.
See https://core.telegram.org/api/srp#checking-the-password-with-srp.
See https://core.telegram.org/api/end-to-end#sending-a-request.
CheckDHParams checks that g_a, g_b and g params meet key exchange conditions.
https://core.telegram.org/mtproto/auth_key#dh-key-exchange-complete
CheckGP checks whether g generates a cyclic subgroup of prime order (p-1)/2, i.e. is a quadratic residue mod p.
Also check that g is 2, 3, 4, 5, 6 or 7.
This function is needed by some Telegram algorithms(Key generation, SRP 2FA).
See https://core.telegram.org/mtproto/auth_key.
See https://core.telegram.org/api/srp.
DataWithHash prepends data with SHA1(data) and 0..15 random bytes so result
length is divisible by 16.
Use GuessDataWithHash(result) to obtain data.
DecodeRSAPad implements server-side decoder of RSAPad.
DecomposePQ decomposes pq into prime factors such that p < q.
DecryptExchangeAnswer decrypts messages created during key exchange.
DefaultRand returns default entropy source.
EncryptExchangeAnswer encrypts messages created during key exchange.
FillBytes is safe version of (*big.Int).FillBytes.
Returns false if to length is not exact equal to big.Int's.
Otherwise fills to using b and returns true.
GuessDataWithHash guesses data from data_with_hash.
InRange checks whether x is in (min, max) range, i.e. min < x < max.
Keys returns (aes_key, aes_iv) pair for AES-IGE.
See https://core.telegram.org/mtproto/description#defining-aes-key-and-initialization-vector
Example:
key, iv := crypto.Keys(authKey, messageKey, crypto.Client)
cipher, err := aes.NewCipher(key[:])
if err != nil {
return nil, err
}
encryptor := ige.NewIGEEncrypter(cipher, iv[:])
MessageKey computes message key for provided auth_key and padded payload.
NewClientCipher creates new client-side Cipher.
NewServerCipher creates new server-side Cipher.
NewSessionID generates new random int64 from reader.
Use crypto/rand.Reader if session id should be cryptographically safe.
NonceHash1 computes nonce_hash_1.
See https://core.telegram.org/mtproto/auth_key#dh-key-exchange-complete.
OldKeys returns (aes_key, aes_iv) pair for AES-IGE.
See https://core.telegram.org/mtproto/description_v1#defining-aes-key-and-initialization-vector
Example:
key, iv := crypto.OldKeys(authKey, messageKey, crypto.Client)
cipher, err := aes.NewCipher(key[:])
if err != nil {
return nil, err
}
encryptor := ige.NewIGEEncrypter(cipher, iv[:])
Warning: MTProto 1.0 is deprecated.
ParseRSA parses data RSA key in PKCS1 or PKIX forms.
ParseRSAPublicKeys parses data as list of PEM-encdoed public keys.
Prime checks that given number is prime.
RandInt128 generates and returns new random 128-bit integer.
Use crypto/rand.Reader as randSource in production.
RandInt256 generates and returns new random 256-bit integer.
Use crypto/rand.Reader as randSource in production.
RandInt64 returns random int64 from randSource.
RandInt64n returns random int64 from randSource in [0; n).
RSADecryptHashed decrypts given data with RSA.
RSAEncryptHashed encrypts given data with RSA, prefixing with a hash.
RSAFingerprint returns fingerprint of RSA public key as defined in MTProto.
RSAPad encrypts given data with RSA, prefixing with a hash.
See https://core.telegram.org/mtproto/auth_key#presenting-proof-of-work-server-authentication.
RSAPublicDecrypt recovers the message digest from the raw signature
using the signer’s RSA public key.
See also OpenSSL’s RSA_public_decrypt with RSA_NO_PADDING.
ServerSalt computes server salt.
SHA256 returns SHA256 hash.
TempAESKeys returns tmp_aes_key and tmp_aes_iv based on new_nonce and
server_nonce as defined in "Creating an Authorization Key".
The pages are generated with Goldsv0.6.7. (GOOS=linux GOARCH=amd64)
Golds is a Go 101 project developed by Tapir Liu.
PR and bug reports are welcome and can be submitted to the issue list.
Please follow @Go100and1 (reachable from the left QR code) to get the latest news of Golds.
