Commit f03640a1 authored by Chuck Lever's avatar Chuck Lever
Browse files

SUNRPC: Remove .blocksize field from struct gss_krb5_enctype 



It is not clear from documenting comments, specifications, or code
usage what value the gss_krb5_enctype.blocksize field is supposed
to store. The "encryption blocksize" depends only on the cipher
being used, so that value can be derived where it's needed instead
of stored as a constant.

RFC 3961 Section 5.2 says:

> cipher block size, c
>    This is the block size of the block cipher underlying the
>    encryption and decryption functions indicated above, used for key
>    derivation and for the size of the message confounder and initial
>    vector.  (If a block cipher is not in use, some comparable
>    parameter should be determined.)  It must be at least 5 octets.
>
>    This is not actually an independent parameter; rather, it is a
>    property of the functions E and D.  It is listed here to clarify
>    the distinction between it and the message block size, m.

In the Linux kernel's implemenation of the SunRPC RPCSEC GSS
Kerberos 5 mechanism, the cipher block size, which is dependent on
the encryption and decryption transforms, is used only in
krb5_derive_key(), so it is straightforward to replace it.

Tested-by: default avatarScott Mayhew <smayhew@redhat.com>
Reviewed-by: default avatarSimo Sorce <simo@redhat.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 97648b94

include/linux/sunrpc/gss_krb5.h

+0 −1
Original line number Diff line number Diff line
@@ -64,7 +64,6 @@ struct gss_krb5_enctype { 
	const char		*cksum_name;	/* crypto checksum name */

	const u16		signalg;	/* signing algorithm */

	const u16		sealalg;	/* sealing algorithm */

	const u32		blocksize;	/* encryption blocksize */

	const u32		conflen;	/* confounder length

						   (normally the same as

						   the blocksize) */

net/sunrpc/auth_gss/gss_krb5_keys.c

+1 −3
Original line number Diff line number Diff line
@@ -150,7 +150,6 @@ u32 krb5_derive_key(const struct gss_krb5_enctype *gk5e, 
	struct crypto_sync_skcipher *cipher;

	u32 ret = EINVAL;



	blocksize = gk5e->blocksize;

	keybytes = gk5e->keybytes;

	keylength = gk5e->keylength;
@@ -160,11 +159,10 @@ u32 krb5_derive_key(const struct gss_krb5_enctype *gk5e, 
	cipher = crypto_alloc_sync_skcipher(gk5e->encrypt_name, 0, 0);

	if (IS_ERR(cipher))

		goto err_return;

	blocksize = crypto_sync_skcipher_blocksize(cipher);

	if (crypto_sync_skcipher_setkey(cipher, inkey->data, inkey->len))

		goto err_return;



	/* allocate and set up buffers */



	ret = ENOMEM;

	inblockdata = kmalloc(blocksize, gfp_mask);

	if (inblockdata == NULL)

net/sunrpc/auth_gss/gss_krb5_mech.c

+0 −4
Original line number Diff line number Diff line
@@ -47,7 +47,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = { 
	  .sealalg = SEAL_ALG_DES,

	  .keybytes = 7,

	  .keylength = 8,

	  .blocksize = 8,

	  .conflen = 8,

	  .cksumlength = 8,

	  .keyed_cksum = 0,
@@ -69,7 +68,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = { 
	  .sealalg = SEAL_ALG_DES3KD,

	  .keybytes = 21,

	  .keylength = 24,

	  .blocksize = 8,

	  .conflen = 8,

	  .cksumlength = 20,

	  .keyed_cksum = 1,
@@ -92,7 +90,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = { 
	  .sealalg = -1,

	  .keybytes = 16,

	  .keylength = 16,

	  .blocksize = 16,

	  .conflen = 16,

	  .cksumlength = 12,

	  .keyed_cksum = 1,
@@ -115,7 +112,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = { 
	  .sealalg = -1,

	  .keybytes = 32,

	  .keylength = 32,

	  .blocksize = 16,

	  .conflen = 16,

	  .cksumlength = 12,

	  .keyed_cksum = 1,