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Merge the ssh1_cipher type into ssh2_cipher.

The aim of this reorganisation is to make it easier to test all the
ciphers in PuTTY in a uniform way. It was inconvenient that there were
two separate vtable systems for the ciphers used in SSH-1 and SSH-2
with different functionality.

Now there's only one type, called ssh_cipher. But really it's the old
ssh2_cipher, just renamed: I haven't made any changes to the API on
the SSH-2 side. Instead, I've removed ssh1_cipher completely, and
adapted the SSH-1 BPP to use the SSH-2 style API.

(The relevant differences are that ssh1_cipher encapsulated both the
sending and receiving directions in one object - so now ssh1bpp has to
make a separate cipher instance per direction - and that ssh1_cipher
automatically initialised the IV to all zeroes, which ssh1bpp now has
to do by hand.)

The previous ssh1_cipher vtable for single-DES has been removed
completely, because when converted into the new API it became
identical to the SSH-2 single-DES vtable; so now there's just one
vtable for DES-CBC which works in both protocols. The other two SSH-1
ciphers each had to stay separate, because 3DES is completely
different between SSH-1 and SSH-2 (three layers of CBC structure
versus one), and Blowfish varies in endianness and key length between
the two.

(Actually, while I'm here, I've only just noticed that the SSH-1
Blowfish cipher mis-describes itself in log messages as Blowfish-128.
In fact it passes the whole of the input key buffer, which has length
SSH1_SESSION_KEY_LENGTH == 32 bytes == 256 bits. So it's actually
Blowfish-256, and has been all along!)
This commit is contained in:
Simon Tatham
2019-01-17 18:06:08 +00:00
parent 20930e7d0c
commit 986508a570
22 changed files with 465 additions and 611 deletions

View File

@ -54,7 +54,7 @@ void ssh_bpp_free(BinaryPacketProtocol *bpp);
BinaryPacketProtocol *ssh1_bpp_new(LogContext *logctx);
void ssh1_bpp_new_cipher(BinaryPacketProtocol *bpp,
const ssh1_cipheralg *cipher,
const ssh_cipheralg *cipher,
const void *session_key);
/* This is only called from outside the BPP in server mode; in client
* mode the BPP detects compression start time automatically by
@ -104,12 +104,12 @@ BinaryPacketProtocol *ssh2_bpp_new(
LogContext *logctx, struct DataTransferStats *stats, bool is_server);
void ssh2_bpp_new_outgoing_crypto(
BinaryPacketProtocol *bpp,
const ssh2_cipheralg *cipher, const void *ckey, const void *iv,
const ssh_cipheralg *cipher, const void *ckey, const void *iv,
const ssh2_macalg *mac, bool etm_mode, const void *mac_key,
const ssh_compression_alg *compression, bool delayed_compression);
void ssh2_bpp_new_incoming_crypto(
BinaryPacketProtocol *bpp,
const ssh2_cipheralg *cipher, const void *ckey, const void *iv,
const ssh_cipheralg *cipher, const void *ckey, const void *iv,
const ssh2_macalg *mac, bool etm_mode, const void *mac_key,
const ssh_compression_alg *compression, bool delayed_compression);