gss_krb5: Add support for rc4-hmac encryption
Add necessary changes to add kernel support for the rc4-hmac Kerberos
encryption type used by Microsoft and described in rfc4757.
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>
diff --git a/net/sunrpc/auth_gss/gss_krb5_seqnum.c b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
index 83b5930..415c013 100644
--- a/net/sunrpc/auth_gss/gss_krb5_seqnum.c
+++ b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
@@ -39,6 +39,38 @@
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
+static s32
+krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
+ unsigned char *cksum, unsigned char *buf)
+{
+ struct crypto_blkcipher *cipher;
+ unsigned char plain[8];
+ s32 code;
+
+ dprintk("RPC: %s:\n", __func__);
+ cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+ CRYPTO_ALG_ASYNC);
+ if (IS_ERR(cipher))
+ return PTR_ERR(cipher);
+
+ plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
+ plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
+ plain[2] = (unsigned char) ((seqnum >> 8) & 0xff);
+ plain[3] = (unsigned char) ((seqnum >> 0) & 0xff);
+ plain[4] = direction;
+ plain[5] = direction;
+ plain[6] = direction;
+ plain[7] = direction;
+
+ code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
+ if (code)
+ goto out;
+
+ code = krb5_encrypt(cipher, cksum, plain, buf, 8);
+out:
+ crypto_free_blkcipher(cipher);
+ return code;
+}
s32
krb5_make_seq_num(struct krb5_ctx *kctx,
struct crypto_blkcipher *key,
@@ -48,6 +80,10 @@
{
unsigned char plain[8];
+ if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
+ return krb5_make_rc4_seq_num(kctx, direction, seqnum,
+ cksum, buf);
+
plain[0] = (unsigned char) (seqnum & 0xff);
plain[1] = (unsigned char) ((seqnum >> 8) & 0xff);
plain[2] = (unsigned char) ((seqnum >> 16) & 0xff);
@@ -61,6 +97,43 @@
return krb5_encrypt(key, cksum, plain, buf, 8);
}
+static s32
+krb5_get_rc4_seq_num(struct krb5_ctx *kctx, unsigned char *cksum,
+ unsigned char *buf, int *direction, s32 *seqnum)
+{
+ struct crypto_blkcipher *cipher;
+ unsigned char plain[8];
+ s32 code;
+
+ dprintk("RPC: %s:\n", __func__);
+ cipher = crypto_alloc_blkcipher(kctx->gk5e->encrypt_name, 0,
+ CRYPTO_ALG_ASYNC);
+ if (IS_ERR(cipher))
+ return PTR_ERR(cipher);
+
+ code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
+ if (code)
+ goto out;
+
+ code = krb5_decrypt(cipher, cksum, buf, plain, 8);
+ if (code)
+ goto out;
+
+ if ((plain[4] != plain[5]) || (plain[4] != plain[6])
+ || (plain[4] != plain[7])) {
+ code = (s32)KG_BAD_SEQ;
+ goto out;
+ }
+
+ *direction = plain[4];
+
+ *seqnum = ((plain[0] << 24) | (plain[1] << 16) |
+ (plain[2] << 8) | (plain[3]));
+out:
+ crypto_free_blkcipher(cipher);
+ return code;
+}
+
s32
krb5_get_seq_num(struct krb5_ctx *kctx,
unsigned char *cksum,
@@ -73,6 +146,10 @@
dprintk("RPC: krb5_get_seq_num:\n");
+ if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
+ return krb5_get_rc4_seq_num(kctx, cksum, buf,
+ direction, seqnum);
+
if ((code = krb5_decrypt(key, cksum, buf, plain, 8)))
return code;