gss_krb5: Use confounder length in wrap code

All encryption types use a confounder at the beginning of the
wrap token.  In all encryption types except arcfour-hmac, the
confounder is the same as the blocksize.  arcfour-hmac has a
blocksize of one, but uses an eight byte confounder.

Add an entry to the crypto framework definitions for the
confounder length and change the wrap/unwrap code to use
the confounder length rather than assuming it is always
the blocksize.

Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

4 files changed, 17 insertions, 8 deletions

diff --git a/include/linux/sunrpc/gss_krb5.h b/include/linux/sunrpc/gss_krb5.h
index d840856edecc..79f6ac2492f5 100644
--- a/include/linux/sunrpc/gss_krb5.h
+++ b/include/linux/sunrpc/gss_krb5.h
@@ -64,6 +64,9 @@ struct gss_krb5_enctype {
         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) */
         const u32               cksumlength;    /* checksum length */
         const u32               keyed_cksum;    /* is it a keyed cksum? */
         const u32               keybytes;       /* raw key len, in bytes */
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index 33ae7023cf3a..ed4106a3daf2 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -554,9 +554,9 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 
         /* hide the gss token header and insert the confounder */
         offset += GSS_KRB5_TOK_HDR_LEN;
-        if (xdr_extend_head(buf, offset, blocksize))
+        if (xdr_extend_head(buf, offset, kctx->gk5e->conflen))
                 return GSS_S_FAILURE;
-        gss_krb5_make_confounder(buf->head[0].iov_base + offset, blocksize);
+        gss_krb5_make_confounder(buf->head[0].iov_base + offset, kctx->gk5e->conflen);
         offset -= GSS_KRB5_TOK_HDR_LEN;
 
         if (buf->tail[0].iov_base != NULL) {
@@ -726,7 +726,7 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
                 ret = GSS_S_BAD_SIG;
                 goto out_err;
         }
-        *headskip = crypto_blkcipher_blocksize(cipher);
+        *headskip = kctx->gk5e->conflen;
         *tailskip = kctx->gk5e->cksumlength;
 out_err:
         if (ret && ret != GSS_S_BAD_SIG)
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index 893fad71e306..ef6b31349046 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -68,6 +68,7 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
           .keybytes = 7,
           .keylength = 8,
           .blocksize = 8,
+          .conflen = 8,
           .cksumlength = 8,
           .keyed_cksum = 0,
         },
@@ -88,6 +89,7 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
           .keybytes = 21,
           .keylength = 24,
           .blocksize = 8,
+          .conflen = 8,
           .cksumlength = 20,
           .keyed_cksum = 1,
         },
@@ -110,6 +112,7 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
           .keybytes = 16,
           .keylength = 16,
           .blocksize = 16,
+          .conflen = 16,
           .cksumlength = 12,
           .keyed_cksum = 1,
         },
@@ -132,6 +135,7 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
           .keybytes = 32,
           .keylength = 32,
           .blocksize = 16,
+          .conflen = 16,
           .cksumlength = 12,
           .keyed_cksum = 1,
         },
diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index a95e7e0ac0e3..383db891c835 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -168,6 +168,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
         struct page             **tmp_pages;
         u32                     seq_send;
         u8                      *cksumkey;
+        u32                     conflen = kctx->gk5e->conflen;
 
         dprintk("RPC:       %s\n", __func__);
 
@@ -176,7 +177,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
         blocksize = crypto_blkcipher_blocksize(kctx->enc);
         gss_krb5_add_padding(buf, offset, blocksize);
         BUG_ON((buf->len - offset) % blocksize);
-        plainlen = blocksize + buf->len - offset;
+        plainlen = conflen + buf->len - offset;
 
         headlen = g_token_size(&kctx->mech_used,
                 GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength + plainlen) -
@@ -204,7 +205,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
         memset(ptr + 4, 0xff, 4);
         *(__be16 *)(ptr + 4) = cpu_to_le16(kctx->gk5e->sealalg);
 
-        gss_krb5_make_confounder(msg_start, blocksize);
+        gss_krb5_make_confounder(msg_start, conflen);
 
         if (kctx->gk5e->keyed_cksum)
                 cksumkey = kctx->cksum;
@@ -214,7 +215,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
         /* XXXJBF: UGH!: */
         tmp_pages = buf->pages;
         buf->pages = pages;
-        if (make_checksum(kctx, ptr, 8, buf, offset + headlen - blocksize,
+        if (make_checksum(kctx, ptr, 8, buf, offset + headlen - conflen,
                                         cksumkey, KG_USAGE_SEAL, &md5cksum))
                 return GSS_S_FAILURE;
         buf->pages = tmp_pages;
@@ -231,7 +232,7 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
                                seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8)))
                 return GSS_S_FAILURE;
 
-        if (gss_encrypt_xdr_buf(kctx->enc, buf, offset + headlen - blocksize,
+        if (gss_encrypt_xdr_buf(kctx->enc, buf, offset + headlen - conflen,
                                                                         pages))
                 return GSS_S_FAILURE;
 
@@ -254,6 +255,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
         void                    *data_start, *orig_start;
         int                     data_len;
         int                     blocksize;
+        u32                     conflen = kctx->gk5e->conflen;
         int                     crypt_offset;
         u8                      *cksumkey;
 
@@ -327,7 +329,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
 
         blocksize = crypto_blkcipher_blocksize(kctx->enc);
         data_start = ptr + (GSS_KRB5_TOK_HDR_LEN + kctx->gk5e->cksumlength) +
-                                        blocksize;
+                                        conflen;
         orig_start = buf->head[0].iov_base + offset;
         data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start;
         memmove(orig_start, data_start, data_len);