2 * linux/net/sunrpc/gss_krb5_unseal.c
4 * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
6 * Copyright (c) 2000 The Regents of the University of Michigan.
9 * Andy Adamson <andros@umich.edu>
13 * Copyright 1993 by OpenVision Technologies, Inc.
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60 #include <linux/types.h>
61 #include <linux/slab.h>
62 #include <linux/jiffies.h>
63 #include <linux/sunrpc/gss_krb5.h>
64 #include <linux/crypto.h>
67 # define RPCDBG_FACILITY RPCDBG_AUTH
71 /* read_token is a mic token, and message_buffer is the data that the mic was
72 * supposedly taken over. */
75 krb5_read_token(struct krb5_ctx
*ctx
,
76 struct xdr_netobj
*read_token
,
77 struct xdr_buf
*message_buffer
, int *qop_state
)
82 struct xdr_netobj md5cksum
= {.len
= 0, .data
= NULL
};
86 unsigned char *ptr
= (unsigned char *)read_token
->data
;
88 u32 ret
= GSS_S_DEFECTIVE_TOKEN
;
90 dprintk("RPC: krb5_read_token\n");
92 if (g_verify_token_header(&ctx
->mech_used
, &bodysize
, &ptr
,
96 if ((*ptr
++ != ((KG_TOK_MIC_MSG
>>8)&0xff)) ||
97 (*ptr
++ != ( KG_TOK_MIC_MSG
&0xff)) )
100 /* XXX sanity-check bodysize?? */
102 /* get the sign and seal algorithms */
104 signalg
= ptr
[0] + (ptr
[1] << 8);
105 sealalg
= ptr
[2] + (ptr
[3] << 8);
109 if ((ptr
[4] != 0xff) || (ptr
[5] != 0xff))
112 if (sealalg
!= 0xffff)
115 /* there are several mappings of seal algorithms to sign algorithms,
116 but few enough that we can try them all. */
118 if ((ctx
->sealalg
== SEAL_ALG_NONE
&& signalg
> 1) ||
119 (ctx
->sealalg
== SEAL_ALG_1
&& signalg
!= SGN_ALG_3
) ||
120 (ctx
->sealalg
== SEAL_ALG_DES3KD
&&
121 signalg
!= SGN_ALG_HMAC_SHA1_DES3_KD
))
124 /* compute the checksum of the message */
126 /* initialize the the cksum */
128 case SGN_ALG_DES_MAC_MD5
:
129 checksum_type
= CKSUMTYPE_RSA_MD5
;
132 ret
= GSS_S_DEFECTIVE_TOKEN
;
137 case SGN_ALG_DES_MAC_MD5
:
138 ret
= make_checksum(checksum_type
, ptr
- 2, 8,
139 message_buffer
, 0, &md5cksum
);
143 ret
= krb5_encrypt(ctx
->seq
, NULL
, md5cksum
.data
,
148 if (memcmp(md5cksum
.data
+ 8, ptr
+ 14, 8)) {
154 ret
= GSS_S_DEFECTIVE_TOKEN
;
158 /* it got through unscathed. Make sure the context is unexpired */
161 *qop_state
= GSS_C_QOP_DEFAULT
;
165 ret
= GSS_S_CONTEXT_EXPIRED
;
166 if (now
> ctx
->endtime
)
169 /* do sequencing checks */
172 if ((ret
= krb5_get_seq_num(ctx
->seq
, ptr
+ 14, ptr
+ 6, &direction
,
176 if ((ctx
->initiate
&& direction
!= 0xff) ||
177 (!ctx
->initiate
&& direction
!= 0))
180 ret
= GSS_S_COMPLETE
;
182 if (md5cksum
.data
) kfree(md5cksum
.data
);