Adding Protocol specification to docs (WIP) #1727
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@ -500,13 +500,201 @@ getpubkey
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When a node has the hash of a public key (from an address) but not the public
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When a node has the hash of a public key (from an address) but not the public
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key itself, it must send out a request for the public key.
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key itself, it must send out a request for the public key.
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.. list-table::
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:header-rows: 1
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:widths: auto
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* - Field Size
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- Description
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- Data type
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- Comments
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* - 20
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- ripe
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- uchar[]
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- The ripemd hash of the public key. This field is only included when the
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address version is <= 3.
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* - 32
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- tag
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- uchar[]
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- The tag derived from the address version, stream number, and ripe. This
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field is only included when the address version is >= 4.
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pubkey
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pubkey
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^^^^^^
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^^^^^^
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A version 2 pubkey. This is still in use and supported by current clients but
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A version 2 pubkey. This is still in use and supported by current clients but
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new v2 addresses are not generated by clients.
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*new* v2 addresses are not generated by clients.
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.. list-table::
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:header-rows: 1
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:widths: auto
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* - Field Size
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- Description
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- Data type
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- Comments
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* - 4
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- behavior bitfield
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- uint32_t
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- A bitfield of optional behaviors and features that can be expected from
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the node receiving the message.
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* - 64
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- public signing key
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- uchar[]
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- The ECC public key used for signing (uncompressed format;
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normally prepended with \x04 )
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* - 64
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- public encryption key
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- uchar[]
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- The ECC public key used for encryption (uncompressed format;
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normally prepended with \x04 )
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.. list-table:: A version 3 pubkey
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:header-rows: 1
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:widths: auto
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* - Field Size
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- Description
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- Data type
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- Comments
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* - 4
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- behavior bitfield
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- uint32_t
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- A bitfield of optional behaviors and features that can be expected from
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the node receiving the message.
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* - 64
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- public signing key
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- uchar[]
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- The ECC public key used for signing (uncompressed format;
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normally prepended with \x04 )
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* - 64
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- public encryption key
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- uchar[]
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- The ECC public key used for encryption (uncompressed format;
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normally prepended with \x04 )
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* - 1+
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- nonce_trials_per_byte
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- var_int
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- Used to calculate the difficulty target of messages accepted by this
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node. The higher this value, the more difficult the Proof of Work must
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be before this individual will accept the message. This number is the
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average number of nonce trials a node will have to perform to meet the
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Proof of Work requirement. 1000 is the network minimum so any lower
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values will be automatically raised to 1000.
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* - 1+
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- extra_bytes
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- var_int
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- Used to calculate the difficulty target of messages accepted by this
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node. The higher this value, the more difficult the Proof of Work must
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be before this individual will accept the message. This number is added
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to the data length to make sending small messages more difficult.
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1000 is the network minimum so any lower values will be automatically
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raised to 1000.
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* - 1+
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- sig_length
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- var_int
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- Length of the signature
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* - sig_length
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- signature
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- uchar[]
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- The ECDSA signature which, as of protocol v3, covers the object
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header starting with the time, appended with the data described in this
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table down to the extra_bytes.
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.. list-table:: A version 4 pubkey
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:header-rows: 1
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:widths: auto
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* - Field Size
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- Description
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- Data type
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- Comments
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* - 32
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- tag
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- uchar[]
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- The tag, made up of bytes 32-64 of the double hash of the address data
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(see example python code below)
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* - ?
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- encrypted
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- uchar[]
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- Encrypted pubkey data.
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When version 4 pubkeys are created, most of the data in the pubkey is encrypted.
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This is done in such a way that only someone who has the Bitmessage address
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which corresponds to a pubkey can decrypt and use that pubkey. This prevents
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people from gathering pubkeys sent around the network and using the data from
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them to create messages to be used in spam or in flooding attacks.
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In order to encrypt the pubkey data, a double SHA-512 hash is calculated from
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the address version number, stream number, and ripe hash of the Bitmessage
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address that the pubkey corresponds to. The first 32 bytes of this hash are used
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to create a public and private key pair with which to encrypt and decrypt the
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pubkey data, using the same algorithm as message encryption
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(see :doc:`encryption`). The remaining 32 bytes of this hash are added to the
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unencrypted part of the pubkey and used as a tag, as above. This allows nodes to
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determine which pubkey to decrypt when they wish to send a message.
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In PyBitmessage, the double hash of the address data is calculated using the
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python code below:
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.. code-block:: python
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doubleHashOfAddressData = hashlib.sha512(hashlib.sha512(
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encodeVarint(addressVersionNumber) + encodeVarint(streamNumber) + hash
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).digest()).digest()
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.. list-table:: Encrypted data in version 4 pubkeys:
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:header-rows: 1
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:widths: auto
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* - Field Size
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- Description
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- Data type
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- Comments
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* - 4
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- behavior bitfield
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- uint32_t
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- A bitfield of optional behaviors and features that can be expected from
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the node receiving the message.
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* - 64
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- public signing key
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- uchar[]
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- The ECC public key used for signing (uncompressed format;
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normally prepended with \x04 )
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* - 64
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- public encryption key
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- uchar[]
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- The ECC public key used for encryption (uncompressed format;
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normally prepended with \x04 )
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* - 1+
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- nonce_trials_per_byte
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- var_int
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- Used to calculate the difficulty target of messages accepted by this
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node. The higher this value, the more difficult the Proof of Work must
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be before this individual will accept the message. This number is the
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average number of nonce trials a node will have to perform to meet the
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Proof of Work requirement. 1000 is the network minimum so any lower
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values will be automatically raised to 1000.
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* - 1+
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- extra_bytes
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- var_int
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- Used to calculate the difficulty target of messages accepted by this
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node. The higher this value, the more difficult the Proof of Work must
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be before this individual will accept the message. This number is added
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to the data length to make sending small messages more difficult.
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1000 is the network minimum so any lower values will be automatically
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raised to 1000.
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* - 1+
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- sig_length
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- var_int
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- Length of the signature
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* - sig_length
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- signature
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- uchar[]
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- The ECDSA signature which covers everything from the object header
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starting with the time, then appended with the decrypted data down to
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the extra_bytes. This was changed in protocol v3.
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msg
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msg
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^^^
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^^^
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Reference in New Issue
Block a user