diff options
Diffstat (limited to 'doc/DETAILS')
| -rw-r--r-- | doc/DETAILS | 61 |
1 files changed, 60 insertions, 1 deletions
diff --git a/doc/DETAILS b/doc/DETAILS index 7455a38bf..dc3e55421 100644 --- a/doc/DETAILS +++ b/doc/DETAILS @@ -6,6 +6,10 @@ a rmd160 hash value from it. This is used as the fingerprint and the low 64 bits are the keyid. + * Revocation certificates consists only of the signature packet; + "import" knows how to handle this. The rationale behind it is + to keep them small. + @@ -162,7 +166,7 @@ Record Type 6 (hash table) if this is not the correct dir record, we look at the next dir record which is linked by the link field. -Record type 7 (hast list) +Record type 7 (hash list) ------------- see hash table for an explanation. @@ -175,3 +179,58 @@ Record type 7 (hast list) For the current record length of 40, n is 6 + + + +Packet Headers +=============== + +G10 uses PGP 2 packet headers and also understand OpenPGP packet header. +There is one enhavement used ith the old style packet headers: + + CTB bits 10, the "packet-length length bits", have values listed in + the following table: + + 00 - 1-byte packet-length field + 01 - 2-byte packet-length field + 10 - 4-byte packet-length field + 11 - no packet length supplied, unknown packet length + + As indicated in this table, depending on the packet-length length + bits, the remaining 1, 2, 4, or 0 bytes of the packet structure field + are a "packet-length field". The packet-length field is a whole + number field. The value of the packet-length field is defined to be + the value of the whole number field. + + A value of 11 is currently used in one place: on compressed data. + That is, a compressed data block currently looks like <A3 01 . . .>, + where <A3>, binary 10 1000 11, is an indefinite-length packet. The + proper interpretation is "until the end of the enclosing structure", + although it should never appear outermost (where the enclosing + structure is a file). + ++ This will be changed with another version, where the new meaning of ++ the value 11 (see below) will also take place. ++ ++ A value of 11 for other packets enables a special length encoding, ++ which is used in case, where the length of the following packet can ++ not be determined prior to writing the packet; especially this will ++ be used if large amounts of data are processed in filter mode. ++ ++ It works like this: After the CTB (with a length field of 11) a ++ marker field is used, which gives the length of the following datablock. ++ This is a simple 2 byte field (MSB first) containig the amount of data ++ following this field, not including this length field. After this datablock ++ another length field follows, which gives the size of the next datablock. ++ A value of 0 indicates the end of the packet. The maximum size of a ++ data block is limited to 65534, thereby reserving a value of 0xffff for ++ future extensions. These length markers must be insereted into the data ++ stream just before writing the data out. ++ ++ This 2 byte filed is large enough, because the application must buffer ++ this amount of data to prepend the length marker before writing it out. ++ Data block sizes larger than about 32k doesn't make any sense. Note ++ that this may also be used for compressed data streams, but we must use ++ another packet version to tell the application that it can not assume, ++ that this is the last packet. + |