gss_krb5: add support for new token formats in rfc4121
This is a step toward support for AES encryption types which are
required to use the new token formats defined in rfc4121.
Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
[SteveD: Fixed a typo in gss_verify_mic_v2()]
Signed-off-by: Steve Dickson <steved@redhat.com>
[Trond: Got rid of the TEST_ROTATE/TEST_EXTRA_COUNT crap]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index bb76873..ca52ac2 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -197,6 +197,80 @@
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,
+ struct xdr_netobj *cksumout)
+{
+ struct hash_desc desc;
+ struct scatterlist sg[1];
+ int err;
+ u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ unsigned int checksumlen;
+
+ 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;
+ }
+
+ desc.tfm = crypto_alloc_hash(kctx->gk5e->cksum_name, 0,
+ CRYPTO_ALG_ASYNC);
+ if (IS_ERR(desc.tfm))
+ return GSS_S_FAILURE;
+ checksumlen = crypto_hash_digestsize(desc.tfm);
+ desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ err = crypto_hash_setkey(desc.tfm, cksumkey, kctx->gk5e->keylength);
+ if (err)
+ goto out;
+
+ err = crypto_hash_init(&desc);
+ if (err)
+ goto out;
+ err = xdr_process_buf(body, body_offset, body->len - body_offset,
+ checksummer, &desc);
+ if (err)
+ goto out;
+ if (header != NULL) {
+ sg_init_one(sg, header, hdrlen);
+ err = crypto_hash_update(&desc, sg, hdrlen);
+ if (err)
+ goto out;
+ }
+ err = crypto_hash_final(&desc, checksumdata);
+ 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:
+ crypto_free_hash(desc.tfm);
+ return err ? GSS_S_FAILURE : 0;
+}
+
struct encryptor_desc {
u8 iv[GSS_KRB5_MAX_BLOCKSIZE];
struct blkcipher_desc desc;