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_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index 1c8ebd3..4aa46b2 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -340,6 +340,174 @@
return GSS_S_COMPLETE;
}
+/*
+ * We cannot currently handle tokens with rotated data. We need a
+ * generalized routine to rotate the data in place. It is anticipated
+ * that we won't encounter rotated data in the general case.
+ */
+static u32
+rotate_left(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf, u16 rrc)
+{
+ unsigned int realrrc = rrc % (buf->len - offset - GSS_KRB5_TOK_HDR_LEN);
+
+ if (realrrc == 0)
+ return 0;
+
+ dprintk("%s: cannot process token with rotated data: "
+ "rrc %u, realrrc %u\n", __func__, rrc, realrrc);
+ return 1;
+}
+
+static u32
+gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
+ struct xdr_buf *buf, struct page **pages)
+{
+ int blocksize;
+ u8 *ptr, *plainhdr;
+ s32 now;
+ u8 flags = 0x00;
+ __be16 *be16ptr, ec = 0;
+ __be64 *be64ptr;
+ u32 err;
+
+ dprintk("RPC: %s\n", __func__);
+
+ if (kctx->gk5e->encrypt_v2 == NULL)
+ return GSS_S_FAILURE;
+
+ /* make room for gss token header */
+ if (xdr_extend_head(buf, offset, GSS_KRB5_TOK_HDR_LEN))
+ return GSS_S_FAILURE;
+
+ /* construct gss token header */
+ ptr = plainhdr = buf->head[0].iov_base + offset;
+ *ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff);
+ *ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff);
+
+ if ((kctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
+ flags |= KG2_TOKEN_FLAG_SENTBYACCEPTOR;
+ if ((kctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) != 0)
+ flags |= KG2_TOKEN_FLAG_ACCEPTORSUBKEY;
+ /* We always do confidentiality in wrap tokens */
+ flags |= KG2_TOKEN_FLAG_SEALED;
+
+ *ptr++ = flags;
+ *ptr++ = 0xff;
+ be16ptr = (__be16 *)ptr;
+
+ blocksize = crypto_blkcipher_blocksize(kctx->acceptor_enc);
+ *be16ptr++ = cpu_to_be16(ec);
+ /* "inner" token header always uses 0 for RRC */
+ *be16ptr++ = cpu_to_be16(0);
+
+ be64ptr = (__be64 *)be16ptr;
+ spin_lock(&krb5_seq_lock);
+ *be64ptr = cpu_to_be64(kctx->seq_send64++);
+ spin_unlock(&krb5_seq_lock);
+
+ err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, ec, pages);
+ if (err)
+ return err;
+
+ now = get_seconds();
+ return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
+}
+
+static u32
+gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
+{
+ s32 now;
+ u64 seqnum;
+ u8 *ptr;
+ u8 flags = 0x00;
+ u16 ec, rrc;
+ int err;
+ u32 headskip, tailskip;
+ u8 decrypted_hdr[GSS_KRB5_TOK_HDR_LEN];
+ unsigned int movelen;
+
+
+ dprintk("RPC: %s\n", __func__);
+
+ if (kctx->gk5e->decrypt_v2 == NULL)
+ return GSS_S_FAILURE;
+
+ ptr = buf->head[0].iov_base + offset;
+
+ if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_WRAP)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ flags = ptr[2];
+ if ((!kctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
+ (kctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
+ return GSS_S_BAD_SIG;
+
+ if ((flags & KG2_TOKEN_FLAG_SEALED) == 0) {
+ dprintk("%s: token missing expected sealed flag\n", __func__);
+ return GSS_S_DEFECTIVE_TOKEN;
+ }
+
+ if (ptr[3] != 0xff)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ ec = be16_to_cpup((__be16 *)(ptr + 4));
+ rrc = be16_to_cpup((__be16 *)(ptr + 6));
+
+ seqnum = be64_to_cpup((__be64 *)(ptr + 8));
+
+ if (rrc != 0) {
+ err = rotate_left(kctx, offset, buf, rrc);
+ if (err)
+ return GSS_S_FAILURE;
+ }
+
+ err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf,
+ &headskip, &tailskip);
+ if (err)
+ return GSS_S_FAILURE;
+
+ /*
+ * Retrieve the decrypted gss token header and verify
+ * it against the original
+ */
+ err = read_bytes_from_xdr_buf(buf,
+ buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip,
+ decrypted_hdr, GSS_KRB5_TOK_HDR_LEN);
+ if (err) {
+ dprintk("%s: error %u getting decrypted_hdr\n", __func__, err);
+ return GSS_S_FAILURE;
+ }
+ if (memcmp(ptr, decrypted_hdr, 6)
+ || memcmp(ptr + 8, decrypted_hdr + 8, 8)) {
+ dprintk("%s: token hdr, plaintext hdr mismatch!\n", __func__);
+ return GSS_S_FAILURE;
+ }
+
+ /* do sequencing checks */
+
+ /* it got through unscathed. Make sure the context is unexpired */
+ now = get_seconds();
+ if (now > kctx->endtime)
+ return GSS_S_CONTEXT_EXPIRED;
+
+ /*
+ * Move the head data back to the right position in xdr_buf.
+ * We ignore any "ec" data since it might be in the head or
+ * the tail, and we really don't need to deal with it.
+ * Note that buf->head[0].iov_len may indicate the available
+ * head buffer space rather than that actually occupied.
+ */
+ movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len);
+ movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip;
+ BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen >
+ buf->head[0].iov_len);
+ memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen);
+ buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+ buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+
+ return GSS_S_COMPLETE;
+}
+
u32
gss_wrap_kerberos(struct gss_ctx *gctx, int offset,
struct xdr_buf *buf, struct page **pages)
@@ -352,6 +520,9 @@
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);
}
}
@@ -366,6 +537,9 @@
case ENCTYPE_DES_CBC_RAW:
case ENCTYPE_DES3_CBC_RAW:
return gss_unwrap_kerberos_v1(kctx, offset, buf);
+ case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+ case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+ return gss_unwrap_kerberos_v2(kctx, offset, buf);
}
}