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Subject: [PATCH v1 10/41] SUNRPC: Refactor the GSS-API Per Message calls in
 the Kerberos mechanism
From:   Chuck Lever <cel@kernel.org>
To:     linux-nfs@vger.kernel.org
Cc:     dhowells@redhat.com, simo@redhat.com
Date:   Fri, 13 Jan 2023 10:22:31 -0500
Message-ID: <167362335112.8960.4943467133115111378.stgit@bazille.1015granger.net>
In-Reply-To: <167362164696.8960.16701168753472560115.stgit@bazille.1015granger.net>
References: <167362164696.8960.16701168753472560115.stgit@bazille.1015granger.net>
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From: Chuck Lever <chuck.lever@oracle.com>

Replace a number of switches on encryption type so that all of them don't
have to be modified when adding or removing support for an enctype.

Tested-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 include/linux/sunrpc/gss_krb5.h         |   23 ++----
 net/sunrpc/auth_gss/gss_krb5_internal.h |   30 +++++++
 net/sunrpc/auth_gss/gss_krb5_mech.c     |  126 ++++++++++++++++++++++++++++---
 net/sunrpc/auth_gss/gss_krb5_seal.c     |   30 +------
 net/sunrpc/auth_gss/gss_krb5_unseal.c   |   31 +-------
 net/sunrpc/auth_gss/gss_krb5_wrap.c     |   66 +++-------------
 6 files changed, 180 insertions(+), 126 deletions(-)

diff --git a/include/linux/sunrpc/gss_krb5.h b/include/linux/sunrpc/gss_krb5.h
index 65e3c0853a0b..81f4bea7888a 100644
--- a/include/linux/sunrpc/gss_krb5.h
+++ b/include/linux/sunrpc/gss_krb5.h
@@ -86,6 +86,15 @@ struct gss_krb5_enctype {
 	u32 (*decrypt_v2) (struct krb5_ctx *kctx, u32 offset, u32 len,
 			   struct xdr_buf *buf, u32 *headskip,
 			   u32 *tailskip);	/* v2 decryption function */
+	u32 (*get_mic)(struct krb5_ctx *kctx, struct xdr_buf *text,
+		       struct xdr_netobj *token);
+	u32 (*verify_mic)(struct krb5_ctx *kctx, struct xdr_buf *message_buffer,
+			  struct xdr_netobj *read_token);
+	u32 (*wrap)(struct krb5_ctx *kctx, int offset,
+		    struct xdr_buf *buf, struct page **pages);
+	u32 (*unwrap)(struct krb5_ctx *kctx, int offset, int len,
+		      struct xdr_buf *buf, unsigned int *slack,
+		      unsigned int *align);
 };
 
 /* krb5_ctx flags definitions */
@@ -237,20 +246,6 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
 		struct xdr_buf *body, int body_offset, u8 *cksumkey,
 		unsigned int usage, struct xdr_netobj *cksumout);
 
-u32 gss_get_mic_kerberos(struct gss_ctx *, struct xdr_buf *,
-		struct xdr_netobj *);
-
-u32 gss_verify_mic_kerberos(struct gss_ctx *, struct xdr_buf *,
-		struct xdr_netobj *);
-
-u32
-gss_wrap_kerberos(struct gss_ctx *ctx_id, int offset,
-		struct xdr_buf *outbuf, struct page **pages);
-
-u32
-gss_unwrap_kerberos(struct gss_ctx *ctx_id, int offset, int len,
-		struct xdr_buf *buf);
-
 u32
 krb5_encrypt(struct crypto_sync_skcipher *key,
 	     void *iv, void *in, void *out, int length);
diff --git a/net/sunrpc/auth_gss/gss_krb5_internal.h b/net/sunrpc/auth_gss/gss_krb5_internal.h
index c7ebaf964483..c6420f9a6c4e 100644
--- a/net/sunrpc/auth_gss/gss_krb5_internal.h
+++ b/net/sunrpc/auth_gss/gss_krb5_internal.h
@@ -8,6 +8,36 @@
 #ifndef _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H
 #define _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H
 
+/*
+ * GSS Kerberos 5 mechanism Per-Message calls.
+ */
+
+u32 gss_krb5_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
+			struct xdr_netobj *token);
+u32 gss_krb5_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
+			struct xdr_netobj *token);
+
+u32 gss_krb5_verify_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *message_buffer,
+			   struct xdr_netobj *read_token);
+u32 gss_krb5_verify_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *message_buffer,
+			   struct xdr_netobj *read_token);
+
+u32 gss_krb5_wrap_v1(struct krb5_ctx *kctx, int offset,
+		     struct xdr_buf *buf, struct page **pages);
+u32 gss_krb5_wrap_v2(struct krb5_ctx *kctx, int offset,
+		     struct xdr_buf *buf, struct page **pages);
+
+u32 gss_krb5_unwrap_v1(struct krb5_ctx *kctx, int offset, int len,
+		       struct xdr_buf *buf, unsigned int *slack,
+		       unsigned int *align);
+u32 gss_krb5_unwrap_v2(struct krb5_ctx *kctx, int offset, int len,
+		       struct xdr_buf *buf, unsigned int *slack,
+		       unsigned int *align);
+
+/*
+ * Implementation internal functions
+ */
+
 void krb5_make_confounder(struct krb5_ctx *kctx, u8 *p, int conflen);
 
 u32 gss_krb5_checksum(struct crypto_ahash *tfm, char *header, int hdrlen,
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index d7307a267b20..921f1a00fc9d 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -22,6 +22,7 @@
 #include <linux/sunrpc/gss_krb5_enctypes.h>
 
 #include "auth_gss_internal.h"
+#include "gss_krb5_internal.h"
 
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 # define RPCDBG_FACILITY	RPCDBG_AUTH
@@ -43,6 +44,10 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .encrypt = krb5_encrypt,
 	  .decrypt = krb5_decrypt,
 	  .mk_key = NULL,
+	  .get_mic = gss_krb5_get_mic_v1,
+	  .verify_mic = gss_krb5_verify_mic_v1,
+	  .wrap = gss_krb5_wrap_v1,
+	  .unwrap = gss_krb5_unwrap_v1,
 	  .signalg = SGN_ALG_DES_MAC_MD5,
 	  .sealalg = SEAL_ALG_DES,
 	  .keybytes = 7,
@@ -63,6 +68,10 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .encrypt = krb5_encrypt,
 	  .decrypt = krb5_decrypt,
 	  .mk_key = gss_krb5_des3_make_key,
+	  .get_mic = gss_krb5_get_mic_v1,
+	  .verify_mic = gss_krb5_verify_mic_v1,
+	  .wrap = gss_krb5_wrap_v1,
+	  .unwrap = gss_krb5_unwrap_v1,
 	  .signalg = SGN_ALG_HMAC_SHA1_DES3_KD,
 	  .sealalg = SEAL_ALG_DES3KD,
 	  .keybytes = 21,
@@ -85,6 +94,12 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .mk_key = gss_krb5_aes_make_key,
 	  .encrypt_v2 = gss_krb5_aes_encrypt,
 	  .decrypt_v2 = gss_krb5_aes_decrypt,
+
+	  .get_mic = gss_krb5_get_mic_v2,
+	  .verify_mic = gss_krb5_verify_mic_v2,
+	  .wrap = gss_krb5_wrap_v2,
+	  .unwrap = gss_krb5_unwrap_v2,
+
 	  .signalg = -1,
 	  .sealalg = -1,
 	  .keybytes = 16,
@@ -107,6 +122,12 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .mk_key = gss_krb5_aes_make_key,
 	  .encrypt_v2 = gss_krb5_aes_encrypt,
 	  .decrypt_v2 = gss_krb5_aes_decrypt,
+
+	  .get_mic = gss_krb5_get_mic_v2,
+	  .verify_mic = gss_krb5_verify_mic_v2,
+	  .wrap = gss_krb5_wrap_v2,
+	  .unwrap = gss_krb5_unwrap_v2,
+
 	  .signalg = -1,
 	  .sealalg = -1,
 	  .keybytes = 32,
@@ -557,10 +578,8 @@ gss_import_v2_context(const void *p, const void *end, struct krb5_ctx *ctx,
 }
 
 static int
-gss_import_sec_context_kerberos(const void *p, size_t len,
-				struct gss_ctx *ctx_id,
-				time64_t *endtime,
-				gfp_t gfp_mask)
+gss_krb5_import_sec_context(const void *p, size_t len, struct gss_ctx *ctx_id,
+			    time64_t *endtime, gfp_t gfp_mask)
 {
 	const void *end = (const void *)((const char *)p + len);
 	struct  krb5_ctx *ctx;
@@ -589,7 +608,8 @@ gss_import_sec_context_kerberos(const void *p, size_t len,
 }
 
 static void
-gss_delete_sec_context_kerberos(void *internal_ctx) {
+gss_krb5_delete_sec_context(void *internal_ctx)
+{
 	struct krb5_ctx *kctx = internal_ctx;
 
 	crypto_free_sync_skcipher(kctx->seq);
@@ -606,13 +626,97 @@ gss_delete_sec_context_kerberos(void *internal_ctx) {
 	kfree(kctx);
 }
 
+/**
+ * gss_krb5_get_mic - get_mic for the Kerberos GSS mechanism
+ * @gctx: GSS context
+ * @text: plaintext to checksum
+ * @token: buffer into which to write the computed checksum
+ *
+ * Return values:
+ *    %GSS_S_COMPLETE - success, and @token is filled in
+ *    %GSS_S_FAILURE - checksum could not be generated
+ *    %GSS_S_CONTEXT_EXPIRED - Kerberos context is no longer valid
+ */
+static u32 gss_krb5_get_mic(struct gss_ctx *gctx, struct xdr_buf *text,
+			    struct xdr_netobj *token)
+{
+	struct krb5_ctx *kctx = gctx->internal_ctx_id;
+
+	return kctx->gk5e->get_mic(kctx, text, token);
+}
+
+/**
+ * gss_krb5_verify_mic - verify_mic for the Kerberos GSS mechanism
+ * @gctx: GSS context
+ * @message_buffer: plaintext to check
+ * @read_token: received checksum to check
+ *
+ * Return values:
+ *    %GSS_S_COMPLETE - computed and received checksums match
+ *    %GSS_S_DEFECTIVE_TOKEN - received checksum is not valid
+ *    %GSS_S_BAD_SIG - computed and received checksums do not match
+ *    %GSS_S_FAILURE - received checksum could not be checked
+ *    %GSS_S_CONTEXT_EXPIRED - Kerberos context is no longer valid
+ */
+static u32 gss_krb5_verify_mic(struct gss_ctx *gctx,
+			       struct xdr_buf *message_buffer,
+			       struct xdr_netobj *read_token)
+{
+	struct krb5_ctx *kctx = gctx->internal_ctx_id;
+
+	return kctx->gk5e->verify_mic(kctx, message_buffer, read_token);
+}
+
+/**
+ * gss_krb5_wrap - gss_wrap for the Kerberos GSS mechanism
+ * @gctx: initialized GSS context
+ * @offset: byte offset in @buf to start writing the cipher text
+ * @buf: OUT: send buffer
+ * @pages: plaintext to wrap
+ *
+ * Return values:
+ *    %GSS_S_COMPLETE - success, @buf has been updated
+ *    %GSS_S_FAILURE - @buf could not be wrapped
+ *    %GSS_S_CONTEXT_EXPIRED - Kerberos context is no longer valid
+ */
+static u32 gss_krb5_wrap(struct gss_ctx *gctx, int offset,
+			 struct xdr_buf *buf, struct page **pages)
+{
+	struct krb5_ctx	*kctx = gctx->internal_ctx_id;
+
+	return kctx->gk5e->wrap(kctx, offset, buf, pages);
+}
+
+/**
+ * gss_krb5_unwrap - gss_unwrap for the Kerberos GSS mechanism
+ * @gctx: initialized GSS context
+ * @offset: starting byte offset into @buf
+ * @len: size of ciphertext to unwrap
+ * @buf: ciphertext to unwrap
+ *
+ * Return values:
+ *    %GSS_S_COMPLETE - success, @buf has been updated
+ *    %GSS_S_DEFECTIVE_TOKEN - received blob is not valid
+ *    %GSS_S_BAD_SIG - computed and received checksums do not match
+ *    %GSS_S_FAILURE - @buf could not be unwrapped
+ *    %GSS_S_CONTEXT_EXPIRED - Kerberos context is no longer valid
+ */
+static u32 gss_krb5_unwrap(struct gss_ctx *gctx, int offset,
+			   int len, struct xdr_buf *buf)
+{
+	struct krb5_ctx	*kctx = gctx->internal_ctx_id;
+
+	return kctx->gk5e->unwrap(kctx, offset, len, buf,
+				  &gctx->slack, &gctx->align);
+}
+
 static const struct gss_api_ops gss_kerberos_ops = {
-	.gss_import_sec_context	= gss_import_sec_context_kerberos,
-	.gss_get_mic		= gss_get_mic_kerberos,
-	.gss_verify_mic		= gss_verify_mic_kerberos,
-	.gss_wrap		= gss_wrap_kerberos,
-	.gss_unwrap		= gss_unwrap_kerberos,
-	.gss_delete_sec_context	= gss_delete_sec_context_kerberos,
+	.gss_import_sec_context	= gss_krb5_import_sec_context,
+	.gss_get_mic		= gss_krb5_get_mic,
+	.gss_verify_mic		= gss_krb5_verify_mic,
+	.gss_wrap		= gss_krb5_wrap,
+	.gss_unwrap		= gss_krb5_unwrap,
+	.gss_delete_sec_context	= gss_krb5_delete_sec_context,
 };
 
 static struct pf_desc gss_kerberos_pfs[] = {
diff --git a/net/sunrpc/auth_gss/gss_krb5_seal.c b/net/sunrpc/auth_gss/gss_krb5_seal.c
index 1d6f8a345354..f74125407588 100644
--- a/net/sunrpc/auth_gss/gss_krb5_seal.c
+++ b/net/sunrpc/auth_gss/gss_krb5_seal.c
@@ -125,9 +125,9 @@ setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token)
 	return krb5_hdr;
 }
 
-static u32
-gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
-		struct xdr_netobj *token)
+u32
+gss_krb5_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
+		    struct xdr_netobj *token)
 {
 	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
 	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
@@ -164,9 +164,9 @@ gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
 	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 }
 
-static u32
-gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
-		struct xdr_netobj *token)
+u32
+gss_krb5_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
+		    struct xdr_netobj *token)
 {
 	struct crypto_ahash *tfm = ctx->initiate ?
 				   ctx->initiator_sign : ctx->acceptor_sign;
@@ -194,21 +194,3 @@ gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
 	now = ktime_get_real_seconds();
 	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 }
-
-u32
-gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
-		     struct xdr_netobj *token)
-{
-	struct krb5_ctx		*ctx = gss_ctx->internal_ctx_id;
-
-	switch (ctx->enctype) {
-	default:
-		BUG();
-	case ENCTYPE_DES_CBC_RAW:
-	case ENCTYPE_DES3_CBC_RAW:
-		return gss_get_mic_v1(ctx, text, token);
-	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
-	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
-		return gss_get_mic_v2(ctx, text, token);
-	}
-}
diff --git a/net/sunrpc/auth_gss/gss_krb5_unseal.c b/net/sunrpc/auth_gss/gss_krb5_unseal.c
index d52103f1203b..939d199eb7b7 100644
--- a/net/sunrpc/auth_gss/gss_krb5_unseal.c
+++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c
@@ -73,9 +73,9 @@
 /* read_token is a mic token, and message_buffer is the data that the mic was
  * supposedly taken over. */
 
-static u32
-gss_verify_mic_v1(struct krb5_ctx *ctx,
-		struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
+u32
+gss_krb5_verify_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *message_buffer,
+		       struct xdr_netobj *read_token)
 {
 	int			signalg;
 	int			sealalg;
@@ -145,9 +145,9 @@ gss_verify_mic_v1(struct krb5_ctx *ctx,
 	return GSS_S_COMPLETE;
 }
 
-static u32
-gss_verify_mic_v2(struct krb5_ctx *ctx,
-		struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
+u32
+gss_krb5_verify_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *message_buffer,
+		       struct xdr_netobj *read_token)
 {
 	struct crypto_ahash *tfm = ctx->initiate ?
 				   ctx->acceptor_sign : ctx->initiator_sign;
@@ -202,22 +202,3 @@ gss_verify_mic_v2(struct krb5_ctx *ctx,
 
 	return GSS_S_COMPLETE;
 }
-
-u32
-gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
-			struct xdr_buf *message_buffer,
-			struct xdr_netobj *read_token)
-{
-	struct krb5_ctx *ctx = gss_ctx->internal_ctx_id;
-
-	switch (ctx->enctype) {
-	default:
-		BUG();
-	case ENCTYPE_DES_CBC_RAW:
-	case ENCTYPE_DES3_CBC_RAW:
-		return gss_verify_mic_v1(ctx, message_buffer, read_token);
-	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
-	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
-		return gss_verify_mic_v2(ctx, message_buffer, read_token);
-	}
-}
diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index 374214f3c463..57085bdec053 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -122,9 +122,9 @@ gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize)
 
 /* XXX factor out common code with seal/unseal. */
 
-static u32
-gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
-		struct xdr_buf *buf, struct page **pages)
+u32
+gss_krb5_wrap_v1(struct krb5_ctx *kctx, int offset,
+		 struct xdr_buf *buf, struct page **pages)
 {
 	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
 	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
@@ -211,10 +211,10 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
 	return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 }
 
-static u32
-gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, int len,
-		       struct xdr_buf *buf, unsigned int *slack,
-		       unsigned int *align)
+u32
+gss_krb5_unwrap_v1(struct krb5_ctx *kctx, int offset, int len,
+		   struct xdr_buf *buf, unsigned int *slack,
+		   unsigned int *align)
 {
 	int			signalg;
 	int			sealalg;
@@ -373,9 +373,9 @@ static void rotate_left(u32 base, struct xdr_buf *buf, unsigned int shift)
 	_rotate_left(&subbuf, shift);
 }
 
-static u32
-gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
-		     struct xdr_buf *buf, struct page **pages)
+u32
+gss_krb5_wrap_v2(struct krb5_ctx *kctx, int offset,
+		 struct xdr_buf *buf, struct page **pages)
 {
 	u8		*ptr;
 	time64_t	now;
@@ -424,10 +424,10 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 	return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 }
 
-static u32
-gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, int len,
-		       struct xdr_buf *buf, unsigned int *slack,
-		       unsigned int *align)
+u32
+gss_krb5_unwrap_v2(struct krb5_ctx *kctx, int offset, int len,
+		   struct xdr_buf *buf, unsigned int *slack,
+		   unsigned int *align)
 {
 	time64_t	now;
 	u8		*ptr;
@@ -524,41 +524,3 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, int len,
 	*slack = *align + XDR_QUADLEN(ec + GSS_KRB5_TOK_HDR_LEN + tailskip);
 	return GSS_S_COMPLETE;
 }
-
-u32
-gss_wrap_kerberos(struct gss_ctx *gctx, int offset,
-		  struct xdr_buf *buf, struct page **pages)
-{
-	struct krb5_ctx	*kctx = gctx->internal_ctx_id;
-
-	switch (kctx->enctype) {
-	default:
-		BUG();
-	case ENCTYPE_DES_CBC_RAW:
-	case ENCTYPE_DES3_CBC_RAW:
-		return gss_wrap_kerberos_v1(kctx, offset, buf, pages);
-	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
-	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
-		return gss_wrap_kerberos_v2(kctx, offset, buf, pages);
-	}
-}
-
-u32
-gss_unwrap_kerberos(struct gss_ctx *gctx, int offset,
-		    int len, struct xdr_buf *buf)
-{
-	struct krb5_ctx	*kctx = gctx->internal_ctx_id;
-
-	switch (kctx->enctype) {
-	default:
-		BUG();
-	case ENCTYPE_DES_CBC_RAW:
-	case ENCTYPE_DES3_CBC_RAW:
-		return gss_unwrap_kerberos_v1(kctx, offset, len, buf,
-					      &gctx->slack, &gctx->align);
-	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
-	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
-		return gss_unwrap_kerberos_v2(kctx, offset, len, buf,
-					      &gctx->slack, &gctx->align);
-	}
-}