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Commit 5de841c5 authored by Marc Dionne's avatar Marc Dionne Committed by Greg Kroah-Hartman
Browse files

rxrpc: Fix rxkad token xdr encoding 



[ Upstream commit 56305118e05b2db8d0395bba640ac9a3aee92624 ]

The session key should be encoded with just the 8 data bytes and
no length; ENCODE_DATA precedes it with a 4 byte length, which
confuses some existing tools that try to parse this format.

Add an ENCODE_BYTES macro that does not include a length, and use
it for the key.  Also adjust the expected length.

Note that commit 774521f3 ("rxrpc: Fix an assertion in
rxrpc_read()") had fixed a BUG by changing the length rather than
fixing the encoding.  The original length was correct.

Fixes: 99455153 ("RxRPC: Parse security index 5 keys (Kerberos 5)")
Signed-off-by: default avatarMarc Dionne <marc.dionne@auristor.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent f9c195bf

net/rxrpc/key.c

+10 −2
Original line number Diff line number Diff line
@@ -1075,7 +1075,7 @@ static long rxrpc_read(const struct key *key, 


		switch (token->security_index) {

		case RXRPC_SECURITY_RXKAD:

			toksize += 9 * 4;	/* viceid, kvno, key*2 + len, begin,

			toksize += 8 * 4;	/* viceid, kvno, key*2, begin,

						 * end, primary, tktlen */

			toksize += RND(token->kad->ticket_len);

			break;
@@ -1141,6 +1141,14 @@ static long rxrpc_read(const struct key *key, 
			memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3));	\

		xdr += (_l + 3) >> 2;					\

	} while(0)

#define ENCODE_BYTES(l, s)						\

	do {								\

		u32 _l = (l);						\

		memcpy(xdr, (s), _l);					\

		if (_l & 3)						\

			memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3));	\

		xdr += (_l + 3) >> 2;					\

	} while(0)

#define ENCODE64(x)					\

	do {						\

		__be64 y = cpu_to_be64(x);		\
@@ -1168,7 +1176,7 @@ static long rxrpc_read(const struct key *key, 
		case RXRPC_SECURITY_RXKAD:

			ENCODE(token->kad->vice_id);

			ENCODE(token->kad->kvno);

			ENCODE_DATA(8, token->kad->session_key);

			ENCODE_BYTES(8, token->kad->session_key);

			ENCODE(token->kad->start);

			ENCODE(token->kad->expiry);

			ENCODE(token->kad->primary_flag);