As it is if user-space passes through a receive buffer that's not
aligned to to the cipher block size, we'll end up encrypting or
decrypting a partial block which causes a spurious EINVAL to be
returned.
This patch fixes this by moving the partial block test after the
af_alg_make_sg call.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When sk_sndbuf is not a multiple of PAGE_SIZE, the limit tests
in sendmsg fail as the limit variable becomes negative and we're
using an unsigned comparison.
The same thing can happen if sk_sndbuf is lowered after a sendmsg
call.
This patch fixes this by always taking the signed maximum of limit
and 0 before we perform the comparison.
It also rounds the value of sk_sndbuf down to a multiple of PAGE_SIZE
so that we don't end up allocating a page only to use a small number
of bytes in it because we're bound by sk_sndbuf.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The error returned from af_alg_make_sg is currently lost and we
always pass on -EINVAL. This patch pases on the underlying error.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the af_alg plugin for symmetric key ciphers,
corresponding to the ablkcipher kernel operation type.
Keys can optionally be set through the setsockopt interface.
Once a sendmsg call occurs without MSG_MORE no further writes
may be made to the socket until all previous data has been read.
IVs and and whether encryption/decryption is performed can be
set through the setsockopt interface or as a control message
to sendmsg.
The interface is completely synchronous, all operations are
carried out in recvmsg(2) and will complete prior to the system
call returning.
The splice(2) interface support reading the user-space data directly
without copying (except that the Crypto API itself may copy the data
if alignment is off).
The recvmsg(2) interface supports directly writing to user-space
without additional copying, i.e., the kernel crypto interface will
receive the user-space address as its output SG list.
Thakns to Miloslav Trmac for reviewing this and contributing
fixes and improvements.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
Herbert Xu