SUNRPC: Remove ->encrypt and ->decrypt methods from struct gss_krb5_enctype

Clean up: ->encrypt is set to only one value. Replace the two
remaining call sites with direct calls to krb5_encrypt().

There have never been any call sites for the ->decrypt() method.
Tested-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

include/linux/sunrpc/gss_krb5.h

@@ -69,12 +69,6 @@ struct gss_krb5_enctype {
 	const u32		keyed_cksum;	/* is it a keyed cksum? */
 	const u32		keybytes;	/* raw key len, in bytes */
 	const u32		keylength;	/* final key len, in bytes */
-	u32 (*encrypt) (struct crypto_sync_skcipher *tfm,
-			void *iv, void *in, void *out,
-			int length);		/* encryption function */
-	u32 (*decrypt) (struct crypto_sync_skcipher *tfm,
-			void *iv, void *in, void *out,
-			int length);		/* decryption function */
 	int (*import_ctx)(struct krb5_ctx *ctx, gfp_t gfp_mask);
 	u32 (*mk_key) (const struct gss_krb5_enctype *gk5e,
 		       struct xdr_netobj *in,
@@ -243,14 +237,6 @@ 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
-krb5_encrypt(struct crypto_sync_skcipher *key,
-	     void *iv, void *in, void *out, int length);
-
-u32
-krb5_decrypt(struct crypto_sync_skcipher *key,
-	     void *iv, void *in, void *out, int length); 
-
 int
 gss_encrypt_xdr_buf(struct crypto_sync_skcipher *tfm, struct xdr_buf *outbuf,
 		    int offset, struct page **pages);

net/sunrpc/auth_gss/gss_krb5_crypto.c

@@ -82,6 +82,22 @@ void krb5_make_confounder(u8 *p, int conflen)
 	get_random_bytes(p, conflen);
 }
 
+/**
+ * krb5_encrypt - simple encryption of an RPCSEC GSS payload
+ * @tfm: initialized cipher transform
+ * @iv: pointer to an IV
+ * @in: plaintext to encrypt
+ * @out: OUT: ciphertext
+ * @length: length of input and output buffers, in bytes
+ *
+ * @iv may be NULL to force the use of an all-zero IV.
+ * The buffer containing the IV must be as large as the
+ * cipher's ivsize.
+ *
+ * Return values:
+ *   %0: @in successfully encrypted into @out
+ *   negative errno: @in not encrypted
+ */
 u32
 krb5_encrypt(
 	struct crypto_sync_skcipher *tfm,
@@ -121,6 +137,22 @@ krb5_encrypt(
 	return ret;
 }
 
+/**
+ * krb5_decrypt - simple decryption of an RPCSEC GSS payload
+ * @tfm: initialized cipher transform
+ * @iv: pointer to an IV
+ * @in: ciphertext to decrypt
+ * @out: OUT: plaintext
+ * @length: length of input and output buffers, in bytes
+ *
+ * @iv may be NULL to force the use of an all-zero IV.
+ * The buffer containing the IV must be as large as the
+ * cipher's ivsize.
+ *
+ * Return values:
+ *   %0: @in successfully decrypted into @out
+ *   negative errno: @in not decrypted
+ */
 u32
 krb5_decrypt(
      struct crypto_sync_skcipher *tfm,
@@ -234,8 +266,8 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
 
 	switch (kctx->gk5e->ctype) {
 	case CKSUMTYPE_RSA_MD5:
-		err = kctx->gk5e->encrypt(kctx->seq, NULL, checksumdata,
-					  checksumdata, checksumlen);
+		err = krb5_encrypt(kctx->seq, NULL, checksumdata,
+				   checksumdata, checksumlen);
 		if (err)
 			goto out;
 		memcpy(cksumout->data,

net/sunrpc/auth_gss/gss_krb5_internal.h

@@ -44,4 +44,10 @@ u32 gss_krb5_checksum(struct crypto_ahash *tfm, char *header, int hdrlen,
 		      const struct xdr_buf *body, int body_offset,
 		      struct xdr_netobj *cksumout);
 
+u32 krb5_encrypt(struct crypto_sync_skcipher *key, void *iv, void *in,
+		 void *out, int length);
+
+u32 krb5_decrypt(struct crypto_sync_skcipher *key, void *iv, void *in,
+		 void *out, int length);
+
 #endif /* _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H */

net/sunrpc/auth_gss/gss_krb5_keys.c

@@ -61,6 +61,8 @@
 #include <linux/sunrpc/xdr.h>
 #include <linux/lcm.h>
 
+#include "gss_krb5_internal.h"
+
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 # define RPCDBG_FACILITY        RPCDBG_AUTH
 #endif
@@ -195,8 +197,8 @@ u32 krb5_derive_key(const struct gss_krb5_enctype *gk5e,
 
 	n = 0;
 	while (n < keybytes) {
-		(*(gk5e->encrypt))(cipher, NULL, inblock.data,
-				   outblock.data, inblock.len);
+		krb5_encrypt(cipher, NULL, inblock.data, outblock.data,
+			     inblock.len);
 
 		if ((keybytes - n) <= outblock.len) {
 			memcpy(rawkey + n, outblock.data, (keybytes - n));

net/sunrpc/auth_gss/gss_krb5_mech.c

@@ -48,8 +48,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .name = "des-cbc-crc",
 	  .encrypt_name = "cbc(des)",
 	  .cksum_name = "md5",
-	  .encrypt = krb5_encrypt,
-	  .decrypt = krb5_decrypt,
 	  .import_ctx = gss_krb5_import_ctx_des,
 	  .mk_key = NULL,
 	  .get_mic = gss_krb5_get_mic_v1,
@@ -72,8 +70,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .name = "des3-hmac-sha1",
 	  .encrypt_name = "cbc(des3_ede)",
 	  .cksum_name = "hmac(sha1)",
-	  .encrypt = krb5_encrypt,
-	  .decrypt = krb5_decrypt,
 	  .import_ctx = gss_krb5_import_ctx_v1,
 	  .mk_key = gss_krb5_des3_make_key,
 	  .get_mic = gss_krb5_get_mic_v1,
@@ -100,8 +96,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .encrypt_name = "cts(cbc(aes))",
 	  .aux_cipher = "cbc(aes)",
 	  .cksum_name = "hmac(sha1)",
-	  .encrypt = krb5_encrypt,
-	  .decrypt = krb5_decrypt,
 	  .import_ctx = gss_krb5_import_ctx_v2,
 	  .mk_key = gss_krb5_aes_make_key,
 	  .encrypt_v2 = gss_krb5_aes_encrypt,
@@ -129,8 +123,6 @@ static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
 	  .encrypt_name = "cts(cbc(aes))",
 	  .aux_cipher = "cbc(aes)",
 	  .cksum_name = "hmac(sha1)",
-	  .encrypt = krb5_encrypt,
-	  .decrypt = krb5_decrypt,
 	  .import_ctx = gss_krb5_import_ctx_v2,
 	  .mk_key = gss_krb5_aes_make_key,
 	  .encrypt_v2 = gss_krb5_aes_encrypt,

net/sunrpc/auth_gss/gss_krb5_seqnum.c

@@ -35,6 +35,8 @@
 #include <linux/types.h>
 #include <linux/sunrpc/gss_krb5.h>
 
+#include "gss_krb5_internal.h"
+
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 # define RPCDBG_FACILITY        RPCDBG_AUTH
 #endif