From: Chuck Lever <chuck.lever@xxxxxxxxxx>
There's no need to keep the integrity keys around if we instead
allocate and key a pair of ahashes and keep those. This not only
enables the subkeys to be destroyed immediately after deriving
them, but it makes the Kerberos integrity code path more efficient.
Tested-by: Scott Mayhew <smayhew@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/linux/sunrpc/gss_krb5.h | 9 +--
net/sunrpc/auth_gss/gss_krb5_crypto.c | 116 +++------------------------------
net/sunrpc/auth_gss/gss_krb5_mech.c | 22 +++---
3 files changed, 23 insertions(+), 124 deletions(-)
diff --git a/include/linux/sunrpc/gss_krb5.h b/include/linux/sunrpc/gss_krb5.h
index a9b29401d6d1..65e3c0853a0b 100644
--- a/include/linux/sunrpc/gss_krb5.h
+++ b/include/linux/sunrpc/gss_krb5.h
@@ -106,6 +106,8 @@ struct krb5_ctx {
struct crypto_sync_skcipher *initiator_enc_aux;
struct crypto_ahash *acceptor_sign;
struct crypto_ahash *initiator_sign;
+ struct crypto_ahash *initiator_integ;
+ struct crypto_ahash *acceptor_integ;
u8 Ksess[GSS_KRB5_MAX_KEYLEN]; /* session key */
u8 cksum[GSS_KRB5_MAX_KEYLEN];
atomic_t seq_send;
@@ -114,8 +116,6 @@ struct krb5_ctx {
atomic64_t confounder;
siphash_key_t confkey;
struct xdr_netobj mech_used;
- u8 initiator_integ[GSS_KRB5_MAX_KEYLEN];
- u8 acceptor_integ[GSS_KRB5_MAX_KEYLEN];
};
/* The length of the Kerberos GSS token header */
@@ -237,11 +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
-make_checksum_v2(struct krb5_ctx *, char *header, int hdrlen,
- struct xdr_buf *body, int body_offset, u8 *key,
- unsigned int usage, struct xdr_netobj *cksum);
-
u32 gss_get_mic_kerberos(struct gss_ctx *, struct xdr_buf *,
struct xdr_netobj *);
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index 3fe16852ccd8..3ffe66779fb7 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -254,93 +254,6 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
return err ? GSS_S_FAILURE : 0;
}
-/*
- * checksum the plaintext data and hdrlen bytes of the token header
- * Per rfc4121, sec. 4.2.4, the checksum is performed over the data
- * body then over the first 16 octets of the MIC token
- * Inclusion of the header data in the calculation of the
- * checksum is optional.
- */
-u32
-make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen,
- struct xdr_buf *body, int body_offset, u8 *cksumkey,
- unsigned int usage, struct xdr_netobj *cksumout)
-{
- struct crypto_ahash *tfm;
- struct ahash_request *req;
- struct scatterlist sg[1];
- int err = -1;
- u8 *checksumdata;
-
- if (kctx->gk5e->keyed_cksum == 0) {
- dprintk("%s: expected keyed hash for %s\n",
- __func__, kctx->gk5e->name);
- return GSS_S_FAILURE;
- }
- if (cksumkey == NULL) {
- dprintk("%s: no key supplied for %s\n",
- __func__, kctx->gk5e->name);
- return GSS_S_FAILURE;
- }
-
- checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_KERNEL);
- if (!checksumdata)
- return GSS_S_FAILURE;
-
- tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(tfm))
- goto out_free_cksum;
-
- req = ahash_request_alloc(tfm, GFP_KERNEL);
- if (!req)
- goto out_free_ahash;
-
- ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
-
- err = crypto_ahash_setkey(tfm, cksumkey, kctx->gk5e->keylength);
- if (err)
- goto out;
-
- err = crypto_ahash_init(req);
- if (err)
- goto out;
- err = xdr_process_buf(body, body_offset, body->len - body_offset,
- checksummer, req);
- if (err)
- goto out;
- if (header != NULL) {
- sg_init_one(sg, header, hdrlen);
- ahash_request_set_crypt(req, sg, NULL, hdrlen);
- err = crypto_ahash_update(req);
- if (err)
- goto out;
- }
- ahash_request_set_crypt(req, NULL, checksumdata, 0);
- err = crypto_ahash_final(req);
- if (err)
- goto out;
-
- cksumout->len = kctx->gk5e->cksumlength;
-
- switch (kctx->gk5e->ctype) {
- case CKSUMTYPE_HMAC_SHA1_96_AES128:
- case CKSUMTYPE_HMAC_SHA1_96_AES256:
- /* note that this truncates the hash */
- memcpy(cksumout->data, checksumdata, kctx->gk5e->cksumlength);
- break;
- default:
- BUG();
- break;
- }
-out:
- ahash_request_free(req);
-out_free_ahash:
- crypto_free_ahash(tfm);
-out_free_cksum:
- kfree(checksumdata);
- return err ? GSS_S_FAILURE : 0;
-}
-
/**
* gss_krb5_checksum - Compute the MAC for a GSS Wrap or MIC token
* @tfm: an initialized hash transform
@@ -697,27 +610,24 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
{
u32 err;
struct xdr_netobj hmac;
- u8 *cksumkey;
u8 *ecptr;
struct crypto_sync_skcipher *cipher, *aux_cipher;
+ struct crypto_ahash *ahash;
int blocksize;
struct page **save_pages;
int nblocks, nbytes;
struct encryptor_desc desc;
u32 cbcbytes;
- unsigned int usage;
unsigned int conflen;
if (kctx->initiate) {
cipher = kctx->initiator_enc;
aux_cipher = kctx->initiator_enc_aux;
- cksumkey = kctx->initiator_integ;
- usage = KG_USAGE_INITIATOR_SEAL;
+ ahash = kctx->initiator_integ;
} else {
cipher = kctx->acceptor_enc;
aux_cipher = kctx->acceptor_enc_aux;
- cksumkey = kctx->acceptor_integ;
- usage = KG_USAGE_ACCEPTOR_SEAL;
+ ahash = kctx->acceptor_integ;
}
blocksize = crypto_sync_skcipher_blocksize(cipher);
conflen = crypto_sync_skcipher_blocksize(cipher);
@@ -757,9 +667,8 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
save_pages = buf->pages;
buf->pages = pages;
- err = make_checksum_v2(kctx, NULL, 0, buf,
- offset + GSS_KRB5_TOK_HDR_LEN,
- cksumkey, usage, &hmac);
+ err = gss_krb5_checksum(ahash, NULL, 0, buf,
+ offset + GSS_KRB5_TOK_HDR_LEN, &hmac);
buf->pages = save_pages;
if (err)
return GSS_S_FAILURE;
@@ -820,25 +729,22 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
{
struct xdr_buf subbuf;
u32 ret = 0;
- u8 *cksum_key;
struct crypto_sync_skcipher *cipher, *aux_cipher;
+ struct crypto_ahash *ahash;
struct xdr_netobj our_hmac_obj;
u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
int nblocks, blocksize, cbcbytes;
struct decryptor_desc desc;
- unsigned int usage;
if (kctx->initiate) {
cipher = kctx->acceptor_enc;
aux_cipher = kctx->acceptor_enc_aux;
- cksum_key = kctx->acceptor_integ;
- usage = KG_USAGE_ACCEPTOR_SEAL;
+ ahash = kctx->acceptor_integ;
} else {
cipher = kctx->initiator_enc;
aux_cipher = kctx->initiator_enc_aux;
- cksum_key = kctx->initiator_integ;
- usage = KG_USAGE_INITIATOR_SEAL;
+ ahash = kctx->initiator_integ;
}
blocksize = crypto_sync_skcipher_blocksize(cipher);
@@ -878,13 +784,9 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
if (ret)
goto out_err;
-
- /* Calculate our hmac over the plaintext data */
our_hmac_obj.len = sizeof(our_hmac);
our_hmac_obj.data = our_hmac;
-
- ret = make_checksum_v2(kctx, NULL, 0, &subbuf, 0,
- cksum_key, usage, &our_hmac_obj);
+ ret = gss_krb5_checksum(ahash, NULL, 0, &subbuf, 0, &our_hmac_obj);
if (ret)
goto out_err;
diff --git a/net/sunrpc/auth_gss/gss_krb5_mech.c b/net/sunrpc/auth_gss/gss_krb5_mech.c
index 0b8ed365a7cb..d7307a267b20 100644
--- a/net/sunrpc/auth_gss/gss_krb5_mech.c
+++ b/net/sunrpc/auth_gss/gss_krb5_mech.c
@@ -447,23 +447,21 @@ context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
/* initiator seal integrity */
set_cdata(cdata, KG_USAGE_INITIATOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
- keyout.data = ctx->initiator_integ;
err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
- if (err) {
- dprintk("%s: Error %d deriving initiator_integ key\n",
- __func__, err);
+ if (err)
+ goto out_free;
+ ctx->initiator_integ = gss_krb5_alloc_hash_v2(ctx, &keyout);
+ if (ctx->initiator_integ == NULL)
goto out_free;
- }
/* acceptor seal integrity */
set_cdata(cdata, KG_USAGE_ACCEPTOR_SEAL, KEY_USAGE_SEED_INTEGRITY);
- keyout.data = ctx->acceptor_integ;
err = krb5_derive_key(ctx->gk5e, &keyin, &keyout, &c, gfp_mask);
- if (err) {
- dprintk("%s: Error %d deriving acceptor_integ key\n",
- __func__, err);
+ if (err)
+ goto out_free;
+ ctx->acceptor_integ = gss_krb5_alloc_hash_v2(ctx, &keyout);
+ if (ctx->acceptor_integ == NULL)
goto out_free;
- }
ret = 0;
out:
@@ -471,6 +469,8 @@ context_derive_keys_new(struct krb5_ctx *ctx, gfp_t gfp_mask)
return ret;
out_free:
+ crypto_free_ahash(ctx->acceptor_integ);
+ crypto_free_ahash(ctx->initiator_integ);
crypto_free_ahash(ctx->acceptor_sign);
crypto_free_ahash(ctx->initiator_sign);
crypto_free_sync_skcipher(ctx->acceptor_enc_aux);
@@ -600,6 +600,8 @@ gss_delete_sec_context_kerberos(void *internal_ctx) {
crypto_free_sync_skcipher(kctx->initiator_enc_aux);
crypto_free_ahash(kctx->acceptor_sign);
crypto_free_ahash(kctx->initiator_sign);
+ crypto_free_ahash(kctx->acceptor_integ);
+ crypto_free_ahash(kctx->initiator_integ);
kfree(kctx->mech_used.data);
kfree(kctx);
}
