diff --git a/data/web/corefork.telegram.org/mtproto.html b/data/web/corefork.telegram.org/mtproto.html index 6fd4cb37ed..dd7870d88c 100644 --- a/data/web/corefork.telegram.org/mtproto.html +++ b/data/web/corefork.telegram.org/mtproto.html @@ -60,9 +60,6 @@ Client developers are required to comply with the Creating an Authorization Key

  • -

    Creating an Authorization Key: Example

    -
  • -
  • Mobile Protocol: Service Messages

  • diff --git a/data/web/corefork.telegram.org/mtproto/auth_key.html b/data/web/corefork.telegram.org/mtproto/auth_key.html index 1c76c3107b..0acb6196b9 100644 --- a/data/web/corefork.telegram.org/mtproto/auth_key.html +++ b/data/web/corefork.telegram.org/mtproto/auth_key.html @@ -44,100 +44,150 @@

    The query format is described using Binary Data Serialization and the TL Language. All large numbers are transmitted as strings containing the required sequence of bytes in big endian order. Hash functions, such as SHA1, return strings (of 20 bytes) which can also be interpreted as big endian numbers. Small numbers (int, long, int128, int256) are normally little endian; however, if they are part of SHA1, the bytes are not rearranged. This way, if long x is the 64 lower-order bits of SHA1 of string s, then the final 8 bytes of 20-byte string SHA1(s) are taken and interpreted as a 64-bit integer.

    Prior to sending off unencrypted messages (required in this instance to generate an authorization key), the client must undergo (p,q) authorization as follows.

    -

    DH exchange initiation

    -

    1) Client sends query to server

    -
    req_pq_multi#be7e8ef1 nonce:int128 = ResPQ;
    +

    DH exchange initiation

    +
      +
    1. +

      Client sends query to server

      +

      req_pq_multi#be7e8ef1 nonce:int128 = ResPQ;

      +
    2. +

    The value of nonce is selected randomly by the client (random number) and identifies the client within this communication. Following this step, it is known to all.

    -

    2) Server sends response of the form

    -
    resPQ#05162463 nonce:int128 server_nonce:int128 pq:string server_public_key_fingerprints:Vector long = ResPQ;
    +
      +
    1. +

      Server sends response of the form

      +

      resPQ#05162463 nonce:int128 server_nonce:int128 pq:string server_public_key_fingerprints:Vector long = ResPQ;

      +
    2. +

    Here, string pq is a representation of a natural number (in binary big endian format). This number is the product of two different odd prime numbers. Normally, pq is less than or equal to 2^63-1. The value of server_nonce is selected randomly by the server; following this step, it is known to all.

    server_public_key_fingerprints is a list of public RSA key fingerprints (64 lower-order bits of SHA1 (server_public_key); the public key is represented as a bare type rsa_public_key n:string e:string = RSAPublicKey, where, as usual, n and e are numbers in big endian format serialized as strings of bytes, following which SHA1 is computed) received by the server.

    All subsequent messages contain the pair (nonce, server_nonce) both in the plain-text, and the encrypted portions which makes it possible to identify a “temporary session” — one run of the key generation protocol described on this page that uses the same (nonce, server_nonce) pair. An intruder could not create a parallel session with the server with the same parameters and reuse parts of server- or client-encrypted messages for its own purposes in such a parallel session, because a different server_nonce would be selected by the server for any new “temporary session”.

    -

    Proof of work

    -

    3) Client decomposes pq into prime factors such that p < q.

    +

    Proof of work

    +
      +
    1. Client decomposes pq into prime factors such that p < q.
    2. +

    This starts a round of Diffie-Hellman key exchanges.

    -

    Presenting proof of work; Server authentication

    -

    4) Client sends query to server

    -
    req_DH_params#d712e4be nonce:int128 server_nonce:int128 p:string q:string public_key_fingerprint:long encrypted_data:string = Server_DH_Params
    +

    Presenting proof of work; Server authentication

    +
      +
    1. +

      Client sends query to server

      +

      req_DH_params#d712e4be nonce:int128 server_nonce:int128 p:string q:string public_key_fingerprint:long encrypted_data:string = Server_DH_Params

      +
    2. +

    Here, encrypted_data is obtained as follows:

    -

    Someone might intercept the query and replace it with their own, independently decomposing pq into factors instead of the client. The only field that it makes sense to modify is new_nonce which would be the one an intruder would have to re-generate (because an intruder cannot decrypt the encrypted data sent by the client). Since all subsequent messages are encrypted using new_nonce or contain new_nonce_hash, they will not be processed by the client (an intruder would not be able to make it look as though they had been generated by the server because they would not contain new_nonce). Therefore, this intercept will only result in the intruder's completing the authorization key generation protocol in place of the client and creating a new key (that has nothing to do with the client); however, the same effect could be achieved simply by creating a new key in one's own name.

    +

    Someone might intercept the query and replace it with their own, independently decomposing pq into factors instead of the client. The only field that it makes sense to modify is new_nonce which would be the one an intruder would have to re-generate (because an intruder cannot decrypt the encrypted data sent by the client). Since all subsequent messages are encrypted using new_nonce or contain new_nonce_hash, they will not be processed by the client (an intruder would not be able to make it look as though they had been generated by the server because they would not contain new_nonce). Therefore, this intercept will only result in the intruder's completing the authorization key generation protocol in place of the client and creating a new key (that has nothing to do with the client); however, the same effect could be achieved simply by creating a new key in one's own name.

    An alternative form of inner data (p_q_inner_data_temp_dc) is used to create temporary keys, that are only stored in the server RAM and are discarded after at most expires_in seconds. The server is free to discard its copy earlier. In all other respects the temporary key generation protocol is the same. After a temporary key is created, the client usually binds it to its principal authorisation key by means of the auth.bindTempAuthKey method, and uses it for all client-server communication until it expires; then a new temporary key is generated. Thus Perfect Forward Secrecy (PFS) in client-server communication is achieved. Read more about PFS »

    4.1) RSA_PAD(data, server_public_key) mentioned above is implemented as follows:

    -

    5) Server responds with:

    -
    server_DH_params_ok#d0e8075c nonce:int128 server_nonce:int128 encrypted_answer:string = Server_DH_Params;
    +
      +
    1. +

      Server responds with:

      +

      server_DH_params_ok#d0e8075c nonce:int128 server_nonce:int128 encrypted_answer:string = Server_DH_Params;

      +
    2. +

    If the query is incorrect, the server returns a -404 error and the handshake must be restarted (any subsequent request also returns -404, even if it is correct).

    Here, encrypted_answer is obtained as follows:

    Following this step, new_nonce is still known to client and server only. The client is certain that it is the server that responded and that the response was generated specifically in response to client query req_DH_params, since the response data are encrypted using new_nonce.

    -

    Client is expected to check whether p = dh_prime is a safe 2048-bit prime (meaning that both p and (p-1)/2 are prime, and that 22047 < p < 22048), 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. After g and p have been checked by the client, it makes sense to cache the result, so as not to repeat lengthy computations in future.

    -

    If the verification takes too long time (which is the case for older mobile devices), one might initially run only 15 Miller—Rabin iterations for verifying primeness of p and (p - 1)/2 with error probability not exceeding one billionth, and do more iterations later in the background.

    -

    Another optimization is to embed into the client application code a small table with some known “good” couples (g,p) (or just known safe primes p, since the condition on g is easily verified during execution), checked during code generation phase, so as to avoid doing such verification during runtime altogether. Server changes these values rarely, thus one usually has to put the current value of server's dh_prime into such a table. For example, current value of dh_prime equals (in big-endian byte order)

    +

    Client is expected to check whether p = dh_prime 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. After g and p have been checked by the client, it makes sense to cache the result, so as not to repeat lengthy computations in future.

    +

    If the verification takes too long time (which is the case for older mobile devices), one might initially run only 15 Miller--Rabin iterations for verifying primeness of p and (p - 1)/2 with error probability not exceeding one billionth, and do more iterations later in the background.

    +

    Another optimization is to embed into the client application code a small table with some known "good" couples (g,p) (or just known safe primes p, since the condition on g is easily verified during execution), checked during code generation phase, so as to avoid doing such verification during runtime altogether. Server changes these values rarely, thus one usually has to put the current value of server's dh_prime into such a table. For example, current value of dh_prime equals (in big-endian byte order)

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
    -

    6) Client computes random 2048-bit number b (using a sufficient amount of entropy) and sends the server a message

    -
    set_client_DH_params#f5045f1f nonce:int128 server_nonce:int128 encrypted_data:string = Set_client_DH_params_answer;
    +
      +
    1. +

      Client computes random 2048-bit number b (using a sufficient amount of entropy) and sends the server a message

      +

      set_client_DH_params#f5045f1f nonce:int128 server_nonce:int128 encrypted_data:string = Set_client_DH_params_answer;

      +
    2. +

    Here, encrypted_data is obtained thus:

    The retry_id field is equal to zero at the time of the first attempt; otherwise, it is equal to auth_key_aux_hash from the previous failed attempt (see Item 9).

    -

    7) Thereafter, auth_key equals pow(g, {ab}) mod dh_prime; on the server, it is computed as pow(g_b, a) mod dh_prime, and on the client as (g_a)^b mod dh_prime.

    -

    8) auth_key_hash is computed := 64 lower-order bits of SHA1 (auth_key). The server checks whether there already is another key with the same auth_key_hash and responds in one of the following ways.

    -

    DH key exchange complete

    -

    9) Server responds in one of three ways:

    -
    dh_gen_ok#3bcbf734 nonce:int128 server_nonce:int128 new_nonce_hash1:int128 = Set_client_DH_params_answer;
    +
      +
    1. +

      Thereafter, auth_key equals pow(g, {ab}) mod dh_prime; on the server, it is computed as pow(g_b, a) mod dh_prime, and on the client as (g_a)^b mod dh_prime.

      +
    2. +
    3. +

      auth_key_hash is computed := 64 lower-order bits of SHA1 (auth_key). The server checks whether there already is another key with the same auth_key_hash and responds in one of the following ways.

      +
    4. +
    +

    DH key exchange complete

    +
      +
    1. +

      Server responds in one of three ways:

      +

      dh_gen_ok#3bcbf734 nonce:int128 server_nonce:int128 new_nonce_hash1:int128 = Set_client_DH_params_answer; dh_gen_retry#46dc1fb9 nonce:int128 server_nonce:int128 new_nonce_hash2:int128 = Set_client_DH_params_answer; -dh_gen_fail#a69dae02 nonce:int128 server_nonce:int128 new_nonce_hash3:int128 = Set_client_DH_params_answer;

    +dh_gen_fail#a69dae02 nonce:int128 server_nonce:int128 new_nonce_hash3:int128 = Set_client_DH_params_answer;

    +
  • + -

    In the other case, the client goes to Item 6) generating a new b.
    In the first case, the client and the server have negotiated auth_key, following which they forget all other temporary data, and the client creates another encrypted session using auth_key. At the same time, server_salt is initially set to substr(new_nonce, 0, 8) XOR substr(server_nonce, 0, 8). If required, the client stores the difference between server_time received in 5) and its local time, to be able always to have a good approximation of server time which is required to generate correct message identifiers.

    +

    In the other case, the client goes to Item 6) generating a new b. +In the first case, the client and the server have negotiated auth_key, following which they forget all other temporary data, and the client creates another encrypted session using auth_key. At the same time, server_salt is initially set to substr(new_nonce, 0, 8) XOR substr(server_nonce, 0, 8). If required, the client stores the difference between server_time received in 5) and its local time, to be able always to have a good approximation of server time which is required to generate correct message identifiers.

    IMPORTANT: Apart from the conditions on the Diffie-Hellman prime dh_prime and generator g, both sides are to check that g, g_a and g_b are greater than 1 and less than dh_prime - 1. We recommend checking that g_a and g_b are between 2^{2048-64} and dh_prime - 2^{2048-64} as well.

    -

    Error Handling (Lost Queries and Responses)

    +

    Error Handling (Lost Queries and Responses)

    If the client fails to receive any response to its query from the server within a certain time interval, it may simply re-send the query. If the server has already sent a response to this query (exactly the same request and not just similar: all the parameters during the repeat request must take on the same values) but it did not get to the client, the server will simply re-send the same response. The server remembers the response for up to 10 minutes after having received the query in 1). If the server has already forgotten the response or the requisite temporary data, the client will have to start from the beginning.

    -

    The server may consider that if the client has already sent in the next query using the data from the previous server response to the specific client, the response is known to have been received by the client and may be forgotten by the server.

    -

    Usage Example

    -

    An example of a complete list of queries required to generate an authorization key is shown on a separate page.

    - +

    The server may consider that if the client has already sent in the next query using the data from the previous server response to the specific client, the response is known to have been received by the client and may be forgotten by the server.

    diff --git a/data/web/corefork.telegram.org/mtproto/samples-auth_key.html b/data/web/corefork.telegram.org/mtproto/samples-auth_key.html index 09c928b793..7458dfb7c2 100644 --- a/data/web/corefork.telegram.org/mtproto/samples-auth_key.html +++ b/data/web/corefork.telegram.org/mtproto/samples-auth_key.html @@ -47,7 +47,7 @@

    In the examples below, the transport headers are omitted:

    -

    For example, for an abridged version of the transport the client sends 0xef as the first byte (important: only prior to the very first data packet), then packet length is encoded by a single byte (0x01-0x7e = data length divided by 4; or 0x7f followed by 3 bytes (little endian) divided by 4) followed by the data themselves. In this case, server responses have the same form (although the server does not send 0xefas the first byte).

    +

    For example, for the abridged version of the transport », the client sends 0xef as the first byte (important: only prior to the very first data packet), then the packet length is encoded with a single byte (0x01-0x7e = data length divided by 4; or 0x7f followed by 3 bytes (little endian) divided by 4) followed by the data itself. In this case, server responses have the same structure (although the server does not send 0xefas the first byte).

    Detailed documentation on creating authorization keys is available here ».

    1. Request for (p,q) Authorization

    @@ -57,7 +57,7 @@ Parameter Offset, Length in bytes -Value +Value (hex) Description @@ -65,54 +65,55 @@ auth_key_id 0, 8 -0 -Since message is in plain text +0000000000000000 +Since the message is in plain text message_id 8, 8 -51e57ac42770964a +af12fb209c111264 Exact unixtime * 2^32 message_length 16, 4 -20 +14000000 (20 in decimal) Message body length %(req_pq_multi) 20, 4 -be7e8ef1 +f18e7ebe req_pq_multi constructor number from TL schema nonce 24, 16 -3E0549828CCA27E966B301A48FECE2FC +C10F3EA71170B031C2EC7365EAFA6D0E Random number

    The header is 20 bytes long, the message body is 20 bytes long, and the entire message is 40 bytes in length.

    -
    0000 | 00 00 00 00 00 00 00 00 4A 96 70 27 C4 7A E5 51
    -0010 | 14 00 00 00 f1 8e 7e be 3E 05 49 82 8C CA 27 E9
    -0020 | 66 B3 01 A4 8F EC E2 FC
    +
    0000 | 00 00 00 00 00 00 00 00 00 00 00 00 9c 11 12 64
    +0010 | 14 00 00 00 f1 8e 7e be C1 0F 3E A7 11 70 B0 31
    +0020 | C2 EC 73 65 EA FA 6D 0E

    2. A response from the server has been received with the following content:

    -
    0000 | 00 00 00 00 00 00 00 00 01 C8 83 1E C9 7A E5 51
    -0010 | 40 00 00 00 63 24 16 05 3E 05 49 82 8C CA 27 E9
    -0020 | 66 B3 01 A4 8F EC E2 FC A5 CF 4D 33 F4 A1 1E A8
    -0030 | 77 BA 4A A5 73 90 73 30 08 17 ED 48 94 1A 08 F9
    -0040 | 81 00 00 00 15 C4 B5 1C 01 00 00 00 21 6B E8 6C
    -0050 | 02 2B B4 C3
    -
    Response decomposition using the following formula:
    +
    0000 | 00 00 00 00 00 00 00 00 01 ac 7d 9a 76 13 12 64
    +0010 | 50 00 00 00 63 24 16 05 C1 0F 3E A7 11 70 B0 31
    +0020 | C2 EC 73 65 EA FA 6D 0E bc 9a 0b 35 61 1c a3 78
    +0030 | 0c 78 c0 17 d2 9d e0 04 08 2a d4 7f de 84 c2 34
    +0040 | 9b 00 00 00 15 c4 b5 1c 03 00 00 00 a5 b7 f7 09
    +0050 | 35 5f c3 0b 21 6b e8 6c 02 2b b4 c3 85 fd 64 de
    +0060 | 85 1d 9d d0
    +
    Response decomposition using the following steps:
    resPQ#05162463 nonce:int128 server_nonce:int128 pq:string server_public_key_fingerprints:Vector long = ResPQ 
    - + @@ -120,71 +121,88 @@ - + - + - + - + - + - + - + - + - + - + - + + + + + + + + + + + + +
    Parameter Offset, Length in bytesValueValue (hex) Description
    auth_key_id 0, 800000000000000000 Since message is in plain text
    message_id 8, 851E57AC91E83C80101ac7d9a76131264 Server message ID
    message_length 16, 46450000000 (80 in decimal) Message body length
    %(resPQ) 20, 40516246363241605 resPQ constructor number from TL schema
    nonce 24, 163E0549828CCA27E966B301A48FECE2FCC10F3EA71170B031C2EC7365EAFA6D0E Value generated by client in Step 1
    server_nonce 40, 16A5CF4D33F4A11EA877BA4AA573907330bc9a0b35611ca3780c78c017d29de004 Server-generated random number
    pq 56, 1217ED48941A08F981082ad47fde84c2340b000000 Single-byte prefix denoting length, an 8-byte string, and three bytes of padding
    %(Vector long) 68, 41cb5c41515c4b51c Vector long constructor number from TL schema
    count 72, 4103000000 Number of elements in key fingerprint list
    fingerprints[]fingerprints[0] 76, 8c3b42b026ce86b21a5b7f709355fc30b64 lower-order bits of SHA1 (server_public_key)
    fingerprints[1]76, 8216be86c022bb4c364 lower-order bits of SHA1 (server_public_key)
    fingerprints[2]76, 885fd64de851d9dd0 64 lower-order bits of SHA1 (server_public_key)
    -

    The server_public_key public key has been selected whose fingerprint corresponds to the only one received from the server: c3b42b026ce86b21.

    -

    3. Pq = 17ED48941A08F981 decomposed into 2 prime cofactors:

    -
    p = 494C553B
    -q = 53911073
    +

    In our case, the client only has the following public keys, with the following fingerprints:

    + +

    Let's choose the only matching key, the one with fingerprint equal to 85fd64de851d9dd0.

    +

    3. Pq = 2ad47fde84c2340b (bigendian => decimal 3086232238342419611) decomposed into 2 prime cofactors:

    +
    p = 1743948187 (bigendian hex 67f2899b)
    +q = 1769681153 (bigendian hex 697b3101)

    4. encrypted_data Generation

    -
    p_q_inner_data#83c95aec pq:string p:string q:string nonce:int128 server_nonce:int128 new_nonce:int256 = P_Q_inner_data
    +
    p_q_inner_data_dc#a9f55f95 pq:bytes p:bytes q:bytes nonce:int128 server_nonce:int128 new_nonce:int256 dc:int = P_Q_inner_data;
    @@ -198,51 +216,57 @@ q = 53911073 - - + + - + - + - + - + - + - + + + + + + +
    %(p_q_inner_data) 0, 483c95aecp_q_inner_data constructor number from TL schema955ff5a9p_q_inner_data_dc constructor number from TL schema
    pq 4, 1217ED48941A08F981082ad47fde84c2340b000000 Single-byte prefix denoting length, 8-byte string, and three bytes of padding
    p 16, 8494C553B0467f2899b000000 First prime cofactor: single-byte prefix denoting length, 4-byte string, and three bytes of padding
    q 24, 85391107304697b3101000000 Second prime cofactor: single-byte prefix denoting length, 4-byte string, and three bytes of padding
    nonce 32, 163E0549828CCA27E966B301A48FECE2FCC10F3EA71170B031C2EC7365EAFA6D0E Value generated by client in Step 1
    server_nonce 48, 16A5CF4D33F4A11EA877BA4AA573907330bc9a0b35611ca3780c78c017d29de004 Value received from server in Step 2
    new_nonce 64, 32311C85DB234AA2640AFC4A76A735CF5B 1F0FD68BD17FA181E1229AD867CC024D311C85DB234AA2640AFC4A76A735CF5B1F0FD68BD17FA181E1229AD867CC024D Client-generated random number
    dc96, 402000000DC ID: 10000 (decimal) has to be added to the DC ID to connect to the test servers; it has to be made negative if the DC we're connecting to is a media (not CDN) DC.

    The serialization of P_Q_inner_data produces some string data. This is followed by encrypted_data:

    SHA1 (data) = DB761C27718A2305044F71F2AD951629D78B2449
     RSA (data_with_hash, server_public_key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
    -

    The length of the final string was 256 bytes.

    +

    The length of the final string is 256 bytes.

    Request to Start Diffie-Hellman Key Exchange
    req_DH_params#d712e4be nonce:int128 server_nonce:int128 p:string q:string public_key_fingerprint:long encrypted_data:string = Server_DH_Params
    @@ -264,49 +288,49 @@ RSA (data_with_hash, server_public_key) = 7BB0100A523161904D9C69FA04BC60DECFC5DD - + - + - + - + - + - + - + - + @@ -317,28 +341,10 @@ RSA (data_with_hash, server_public_key) = 7BB0100A523161904D9C69FA04BC60DECFC5DD
    message_id 8, 851e57ac917717a27fa1bc56176131264 Exact unixtime * 2^32
    message_length 16, 432040010000 (decimal 320) Message body length
    %(req_DH_params) 20, 4d712e4bebee412d7 req_DH_params constructor number from TL schema
    nonce 24, 163E0549828CCA27E966B301A48FECE2FCC10F3EA71170B031C2EC7365EAFA6D0E Value generated by client in Step 1
    server_nonce 40, 16A5CF4D33F4A11EA877BA4AA573907330bc9a0b35611ca3780c78c017d29de004 Value received from server in Step 2
    p 56, 8494C553B0467f2899b000000 First prime cofactor: single-byte prefix denoting length, 4-byte string, and three bytes of padding
    q 64, 85391107304697b3101000000 Second prime cofactor: single-byte prefix denoting length, 4-byte string, and three bytes of padding
    public_key_fingerprint 72, 8c3b42b026ce86b2185fd64de851d9dd0 Fingerprint of public key used
    -
    0000 | 00 00 00 00 00 00 00 00 27 7A 71 17 C9 7A E5 51
    -0010 | 40 01 00 00 BE E4 12 D7 3E 05 49 82 8C CA 27 E9
    -0020 | 66 B3 01 A4 8F EC E2 FC A5 CF 4D 33 F4 A1 1E A8
    -0030 | 77 BA 4A A5 73 90 73 30 04 49 4C 55 3B 00 00 00
    -0040 | 04 53 91 10 73 00 00 00 21 6B E8 6C 02 2B B4 C3
    -0050 | FE 00 01 00 7B B0 10 0A 52 31 61 90 4D 9C 69 FA
    -0060 | 04 BC 60 DE CF C5 DD 74 B9 99 95 C7 68 EB 60 D8
    -0070 | 71 6E 21 09 BA F2 D4 60 1D AB 6B 09 61 0D C1 10
    -0080 | 67 BB 89 02 1E 09 47 1F CF A5 2D BD 0F 23 20 4A
    -0090 | D8 CA 8B 01 2B F4 0A 11 2F 44 69 5A B6 C2 66 95
    -00A0 | 53 86 11 4E F5 21 1E 63 72 22 7A DB D3 49 95 D3
    -00B0 | E0 E5 FF 02 EC 63 A4 3F 99 26 87 89 62 F7 C5 70
    -00C0 | E6 A6 E7 8B F8 36 6A F9 17 A5 27 26 75 C4 60 64
    -00D0 | BE 62 E3 E2 02 EF A8 B1 AD FB 1C 32 A8 98 C2 98
    -00E0 | 7B E2 7B 5F 31 D5 7C 9B B9 63 AB CB 73 4B 16 F6
    -00F0 | 52 CE DB 42 93 CB B7 C8 78 A3 A3 FF AC 9D BE A9
    -0100 | DF 7C 67 BC 9E 95 08 E1 11 C7 8F C4 6E 05 7F 5C
    -0110 | 65 AD E3 81 D9 1F EE 43 0A 6B 57 6A 99 BD F8 55
    -0120 | 1F DB 1B E2 B5 70 69 B1 A4 57 30 61 8F 27 42 7E
    -0130 | 8A 04 72 0B 49 71 EF 4A 92 15 98 3D 68 F2 83 0C
    -0140 | 3E AA 6E 40 38 55 62 F9 70 D3 8A 05 C9 F1 24 6D
    -0150 | C3 34 38 E6
    +
    0000 | 00 00 00 00 00 00 00 00 fa 1b c5 61 76 13 12 64
    +0010 | 40 01 00 00 BE E4 12 D7 C1 0F 3E A7 11 70 B0 31
    +0020 | C2 EC 73 65 EA FA 6D 0E bc 9a 0b 35 61 1c a3 78
    +0030 | 0c 78 c0 17 d2 9d e0 04

    5. A response from the server has been received with the following content:

    0000 | 00 00 00 00 00 00 00 00 01 54 43 36 CB 7A E5 51
     0010 | 78 02 00 00 5C 07 E8 D0 3E 05 49 82 8C CA 27 E9