mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 13:55:32 +00:00
RPCSEC_GSS: Add support for privacy to krb5 rpcsec_gss mechanism.
Add support for privacy to the krb5 rpcsec_gss mechanism. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
parent
bfa91516b5
commit
14ae162c24
7 changed files with 552 additions and 7 deletions
|
@ -116,7 +116,7 @@ enum seal_alg {
|
|||
|
||||
s32
|
||||
make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
|
||||
struct xdr_netobj *cksum);
|
||||
int body_offset, struct xdr_netobj *cksum);
|
||||
|
||||
u32
|
||||
krb5_make_token(struct krb5_ctx *context_handle, int qop_req,
|
||||
|
@ -128,6 +128,15 @@ krb5_read_token(struct krb5_ctx *context_handle,
|
|||
struct xdr_netobj *input_token_buffer,
|
||||
struct xdr_buf *message_buffer, int *qop_state);
|
||||
|
||||
u32
|
||||
gss_wrap_kerberos(struct gss_ctx *ctx_id, u32 qop, int offset,
|
||||
struct xdr_buf *outbuf, struct page **pages);
|
||||
|
||||
u32
|
||||
gss_unwrap_kerberos(struct gss_ctx *ctx_id, u32 *qop, int offset,
|
||||
struct xdr_buf *buf);
|
||||
|
||||
|
||||
u32
|
||||
krb5_encrypt(struct crypto_tfm * key,
|
||||
void *iv, void *in, void *out, int length);
|
||||
|
@ -136,6 +145,13 @@ u32
|
|||
krb5_decrypt(struct crypto_tfm * key,
|
||||
void *iv, void *in, void *out, int length);
|
||||
|
||||
int
|
||||
gss_encrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *outbuf, int offset,
|
||||
struct page **pages);
|
||||
|
||||
int
|
||||
gss_decrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *inbuf, int offset);
|
||||
|
||||
s32
|
||||
krb5_make_seq_num(struct crypto_tfm * key,
|
||||
int direction,
|
||||
|
|
|
@ -10,7 +10,7 @@ auth_rpcgss-objs := auth_gss.o gss_generic_token.o \
|
|||
obj-$(CONFIG_RPCSEC_GSS_KRB5) += rpcsec_gss_krb5.o
|
||||
|
||||
rpcsec_gss_krb5-objs := gss_krb5_mech.o gss_krb5_seal.o gss_krb5_unseal.o \
|
||||
gss_krb5_seqnum.o
|
||||
gss_krb5_seqnum.o gss_krb5_wrap.o
|
||||
|
||||
obj-$(CONFIG_RPCSEC_GSS_SPKM3) += rpcsec_gss_spkm3.o
|
||||
|
||||
|
|
|
@ -218,7 +218,7 @@ checksummer(struct scatterlist *sg, void *data)
|
|||
/* checksum the plaintext data and hdrlen bytes of the token header */
|
||||
s32
|
||||
make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
|
||||
struct xdr_netobj *cksum)
|
||||
int body_offset, struct xdr_netobj *cksum)
|
||||
{
|
||||
char *cksumname;
|
||||
struct crypto_tfm *tfm = NULL; /* XXX add to ctx? */
|
||||
|
@ -243,7 +243,8 @@ make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
|
|||
crypto_digest_init(tfm);
|
||||
buf_to_sg(sg, header, hdrlen);
|
||||
crypto_digest_update(tfm, sg, 1);
|
||||
process_xdr_buf(body, 0, body->len, checksummer, tfm);
|
||||
process_xdr_buf(body, body_offset, body->len - body_offset,
|
||||
checksummer, tfm);
|
||||
crypto_digest_final(tfm, cksum->data);
|
||||
code = 0;
|
||||
out:
|
||||
|
@ -252,3 +253,154 @@ make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
|
|||
}
|
||||
|
||||
EXPORT_SYMBOL(make_checksum);
|
||||
|
||||
struct encryptor_desc {
|
||||
u8 iv[8]; /* XXX hard-coded blocksize */
|
||||
struct crypto_tfm *tfm;
|
||||
int pos;
|
||||
struct xdr_buf *outbuf;
|
||||
struct page **pages;
|
||||
struct scatterlist infrags[4];
|
||||
struct scatterlist outfrags[4];
|
||||
int fragno;
|
||||
int fraglen;
|
||||
};
|
||||
|
||||
static int
|
||||
encryptor(struct scatterlist *sg, void *data)
|
||||
{
|
||||
struct encryptor_desc *desc = data;
|
||||
struct xdr_buf *outbuf = desc->outbuf;
|
||||
struct page *in_page;
|
||||
int thislen = desc->fraglen + sg->length;
|
||||
int fraglen, ret;
|
||||
int page_pos;
|
||||
|
||||
/* Worst case is 4 fragments: head, end of page 1, start
|
||||
* of page 2, tail. Anything more is a bug. */
|
||||
BUG_ON(desc->fragno > 3);
|
||||
desc->infrags[desc->fragno] = *sg;
|
||||
desc->outfrags[desc->fragno] = *sg;
|
||||
|
||||
page_pos = desc->pos - outbuf->head[0].iov_len;
|
||||
if (page_pos >= 0 && page_pos < outbuf->page_len) {
|
||||
/* pages are not in place: */
|
||||
int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT;
|
||||
in_page = desc->pages[i];
|
||||
} else {
|
||||
in_page = sg->page;
|
||||
}
|
||||
desc->infrags[desc->fragno].page = in_page;
|
||||
desc->fragno++;
|
||||
desc->fraglen += sg->length;
|
||||
desc->pos += sg->length;
|
||||
|
||||
fraglen = thislen & 7; /* XXX hardcoded blocksize */
|
||||
thislen -= fraglen;
|
||||
|
||||
if (thislen == 0)
|
||||
return 0;
|
||||
|
||||
ret = crypto_cipher_encrypt_iv(desc->tfm, desc->outfrags, desc->infrags,
|
||||
thislen, desc->iv);
|
||||
if (ret)
|
||||
return ret;
|
||||
if (fraglen) {
|
||||
desc->outfrags[0].page = sg->page;
|
||||
desc->outfrags[0].offset = sg->offset + sg->length - fraglen;
|
||||
desc->outfrags[0].length = fraglen;
|
||||
desc->infrags[0] = desc->outfrags[0];
|
||||
desc->infrags[0].page = in_page;
|
||||
desc->fragno = 1;
|
||||
desc->fraglen = fraglen;
|
||||
} else {
|
||||
desc->fragno = 0;
|
||||
desc->fraglen = 0;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
int
|
||||
gss_encrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *buf, int offset,
|
||||
struct page **pages)
|
||||
{
|
||||
int ret;
|
||||
struct encryptor_desc desc;
|
||||
|
||||
BUG_ON((buf->len - offset) % crypto_tfm_alg_blocksize(tfm) != 0);
|
||||
|
||||
memset(desc.iv, 0, sizeof(desc.iv));
|
||||
desc.tfm = tfm;
|
||||
desc.pos = offset;
|
||||
desc.outbuf = buf;
|
||||
desc.pages = pages;
|
||||
desc.fragno = 0;
|
||||
desc.fraglen = 0;
|
||||
|
||||
ret = process_xdr_buf(buf, offset, buf->len - offset, encryptor, &desc);
|
||||
return ret;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(gss_encrypt_xdr_buf);
|
||||
|
||||
struct decryptor_desc {
|
||||
u8 iv[8]; /* XXX hard-coded blocksize */
|
||||
struct crypto_tfm *tfm;
|
||||
struct scatterlist frags[4];
|
||||
int fragno;
|
||||
int fraglen;
|
||||
};
|
||||
|
||||
static int
|
||||
decryptor(struct scatterlist *sg, void *data)
|
||||
{
|
||||
struct decryptor_desc *desc = data;
|
||||
int thislen = desc->fraglen + sg->length;
|
||||
int fraglen, ret;
|
||||
|
||||
/* Worst case is 4 fragments: head, end of page 1, start
|
||||
* of page 2, tail. Anything more is a bug. */
|
||||
BUG_ON(desc->fragno > 3);
|
||||
desc->frags[desc->fragno] = *sg;
|
||||
desc->fragno++;
|
||||
desc->fraglen += sg->length;
|
||||
|
||||
fraglen = thislen & 7; /* XXX hardcoded blocksize */
|
||||
thislen -= fraglen;
|
||||
|
||||
if (thislen == 0)
|
||||
return 0;
|
||||
|
||||
ret = crypto_cipher_decrypt_iv(desc->tfm, desc->frags, desc->frags,
|
||||
thislen, desc->iv);
|
||||
if (ret)
|
||||
return ret;
|
||||
if (fraglen) {
|
||||
desc->frags[0].page = sg->page;
|
||||
desc->frags[0].offset = sg->offset + sg->length - fraglen;
|
||||
desc->frags[0].length = fraglen;
|
||||
desc->fragno = 1;
|
||||
desc->fraglen = fraglen;
|
||||
} else {
|
||||
desc->fragno = 0;
|
||||
desc->fraglen = 0;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
int
|
||||
gss_decrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *buf, int offset)
|
||||
{
|
||||
struct decryptor_desc desc;
|
||||
|
||||
/* XXXJBF: */
|
||||
BUG_ON((buf->len - offset) % crypto_tfm_alg_blocksize(tfm) != 0);
|
||||
|
||||
memset(desc.iv, 0, sizeof(desc.iv));
|
||||
desc.tfm = tfm;
|
||||
desc.fragno = 0;
|
||||
desc.fraglen = 0;
|
||||
return process_xdr_buf(buf, offset, buf->len - offset, decryptor, &desc);
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(gss_decrypt_xdr_buf);
|
||||
|
|
|
@ -226,6 +226,8 @@ static struct gss_api_ops gss_kerberos_ops = {
|
|||
.gss_import_sec_context = gss_import_sec_context_kerberos,
|
||||
.gss_get_mic = gss_get_mic_kerberos,
|
||||
.gss_verify_mic = gss_verify_mic_kerberos,
|
||||
.gss_wrap = gss_wrap_kerberos,
|
||||
.gss_unwrap = gss_unwrap_kerberos,
|
||||
.gss_delete_sec_context = gss_delete_sec_context_kerberos,
|
||||
};
|
||||
|
||||
|
@ -240,6 +242,11 @@ static struct pf_desc gss_kerberos_pfs[] = {
|
|||
.service = RPC_GSS_SVC_INTEGRITY,
|
||||
.name = "krb5i",
|
||||
},
|
||||
[2] = {
|
||||
.pseudoflavor = RPC_AUTH_GSS_KRB5P,
|
||||
.service = RPC_GSS_SVC_PRIVACY,
|
||||
.name = "krb5p",
|
||||
},
|
||||
};
|
||||
|
||||
static struct gss_api_mech gss_kerberos_mech = {
|
||||
|
|
|
@ -116,8 +116,8 @@ krb5_make_token(struct krb5_ctx *ctx, int qop_req,
|
|||
*(u16 *)(krb5_hdr + 2) = htons(ctx->signalg);
|
||||
memset(krb5_hdr + 4, 0xff, 4);
|
||||
|
||||
if (make_checksum(checksum_type, krb5_hdr, 8, text, &md5cksum))
|
||||
goto out_err;
|
||||
if (make_checksum(checksum_type, krb5_hdr, 8, text, 0, &md5cksum))
|
||||
goto out_err;
|
||||
|
||||
switch (ctx->signalg) {
|
||||
case SGN_ALG_DES_MAC_MD5:
|
||||
|
|
|
@ -136,7 +136,7 @@ krb5_read_token(struct krb5_ctx *ctx,
|
|||
switch (signalg) {
|
||||
case SGN_ALG_DES_MAC_MD5:
|
||||
ret = make_checksum(checksum_type, ptr - 2, 8,
|
||||
message_buffer, &md5cksum);
|
||||
message_buffer, 0, &md5cksum);
|
||||
if (ret)
|
||||
goto out;
|
||||
|
||||
|
|
370
net/sunrpc/auth_gss/gss_krb5_wrap.c
Normal file
370
net/sunrpc/auth_gss/gss_krb5_wrap.c
Normal file
|
@ -0,0 +1,370 @@
|
|||
#include <linux/types.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/jiffies.h>
|
||||
#include <linux/sunrpc/gss_krb5.h>
|
||||
#include <linux/random.h>
|
||||
#include <linux/pagemap.h>
|
||||
#include <asm/scatterlist.h>
|
||||
#include <linux/crypto.h>
|
||||
|
||||
#ifdef RPC_DEBUG
|
||||
# define RPCDBG_FACILITY RPCDBG_AUTH
|
||||
#endif
|
||||
|
||||
static inline int
|
||||
gss_krb5_padding(int blocksize, int length)
|
||||
{
|
||||
/* Most of the code is block-size independent but currently we
|
||||
* use only 8: */
|
||||
BUG_ON(blocksize != 8);
|
||||
return 8 - (length & 7);
|
||||
}
|
||||
|
||||
static inline void
|
||||
gss_krb5_add_padding(struct xdr_buf *buf, int offset, int blocksize)
|
||||
{
|
||||
int padding = gss_krb5_padding(blocksize, buf->len - offset);
|
||||
char *p;
|
||||
struct kvec *iov;
|
||||
|
||||
if (buf->page_len || buf->tail[0].iov_len)
|
||||
iov = &buf->tail[0];
|
||||
else
|
||||
iov = &buf->head[0];
|
||||
p = iov->iov_base + iov->iov_len;
|
||||
iov->iov_len += padding;
|
||||
buf->len += padding;
|
||||
memset(p, padding, padding);
|
||||
}
|
||||
|
||||
static inline int
|
||||
gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize)
|
||||
{
|
||||
u8 *ptr;
|
||||
u8 pad;
|
||||
int len = buf->len;
|
||||
|
||||
if (len <= buf->head[0].iov_len) {
|
||||
pad = *(u8 *)(buf->head[0].iov_base + len - 1);
|
||||
if (pad > buf->head[0].iov_len)
|
||||
return -EINVAL;
|
||||
buf->head[0].iov_len -= pad;
|
||||
goto out;
|
||||
} else
|
||||
len -= buf->head[0].iov_len;
|
||||
if (len <= buf->page_len) {
|
||||
int last = (buf->page_base + len - 1)
|
||||
>>PAGE_CACHE_SHIFT;
|
||||
int offset = (buf->page_base + len - 1)
|
||||
& (PAGE_CACHE_SIZE - 1);
|
||||
ptr = kmap_atomic(buf->pages[last], KM_SKB_SUNRPC_DATA);
|
||||
pad = *(ptr + offset);
|
||||
kunmap_atomic(ptr, KM_SKB_SUNRPC_DATA);
|
||||
goto out;
|
||||
} else
|
||||
len -= buf->page_len;
|
||||
BUG_ON(len > buf->tail[0].iov_len);
|
||||
pad = *(u8 *)(buf->tail[0].iov_base + len - 1);
|
||||
out:
|
||||
/* XXX: NOTE: we do not adjust the page lengths--they represent
|
||||
* a range of data in the real filesystem page cache, and we need
|
||||
* to know that range so the xdr code can properly place read data.
|
||||
* However adjusting the head length, as we do above, is harmless.
|
||||
* In the case of a request that fits into a single page, the server
|
||||
* also uses length and head length together to determine the original
|
||||
* start of the request to copy the request for deferal; so it's
|
||||
* easier on the server if we adjust head and tail length in tandem.
|
||||
* It's not really a problem that we don't fool with the page and
|
||||
* tail lengths, though--at worst badly formed xdr might lead the
|
||||
* server to attempt to parse the padding.
|
||||
* XXX: Document all these weird requirements for gss mechanism
|
||||
* wrap/unwrap functions. */
|
||||
if (pad > blocksize)
|
||||
return -EINVAL;
|
||||
if (buf->len > pad)
|
||||
buf->len -= pad;
|
||||
else
|
||||
return -EINVAL;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline void
|
||||
make_confounder(char *p, int blocksize)
|
||||
{
|
||||
static u64 i = 0;
|
||||
u64 *q = (u64 *)p;
|
||||
|
||||
/* rfc1964 claims this should be "random". But all that's really
|
||||
* necessary is that it be unique. And not even that is necessary in
|
||||
* our case since our "gssapi" implementation exists only to support
|
||||
* rpcsec_gss, so we know that the only buffers we will ever encrypt
|
||||
* already begin with a unique sequence number. Just to hedge my bets
|
||||
* I'll make a half-hearted attempt at something unique, but ensuring
|
||||
* uniqueness would mean worrying about atomicity and rollover, and I
|
||||
* don't care enough. */
|
||||
|
||||
BUG_ON(blocksize != 8);
|
||||
*q = i++;
|
||||
}
|
||||
|
||||
/* Assumptions: the head and tail of inbuf are ours to play with.
|
||||
* The pages, however, may be real pages in the page cache and we replace
|
||||
* them with scratch pages from **pages before writing to them. */
|
||||
/* XXX: obviously the above should be documentation of wrap interface,
|
||||
* and shouldn't be in this kerberos-specific file. */
|
||||
|
||||
/* XXX factor out common code with seal/unseal. */
|
||||
|
||||
u32
|
||||
gss_wrap_kerberos(struct gss_ctx *ctx, u32 qop, int offset,
|
||||
struct xdr_buf *buf, struct page **pages)
|
||||
{
|
||||
struct krb5_ctx *kctx = ctx->internal_ctx_id;
|
||||
s32 checksum_type;
|
||||
struct xdr_netobj md5cksum = {.len = 0, .data = NULL};
|
||||
int blocksize = 0, plainlen;
|
||||
unsigned char *ptr, *krb5_hdr, *msg_start;
|
||||
s32 now;
|
||||
int headlen;
|
||||
struct page **tmp_pages;
|
||||
|
||||
dprintk("RPC: gss_wrap_kerberos\n");
|
||||
|
||||
now = get_seconds();
|
||||
|
||||
if (qop != 0)
|
||||
goto out_err;
|
||||
|
||||
switch (kctx->signalg) {
|
||||
case SGN_ALG_DES_MAC_MD5:
|
||||
checksum_type = CKSUMTYPE_RSA_MD5;
|
||||
break;
|
||||
default:
|
||||
dprintk("RPC: gss_krb5_seal: kctx->signalg %d not"
|
||||
" supported\n", kctx->signalg);
|
||||
goto out_err;
|
||||
}
|
||||
if (kctx->sealalg != SEAL_ALG_NONE && kctx->sealalg != SEAL_ALG_DES) {
|
||||
dprintk("RPC: gss_krb5_seal: kctx->sealalg %d not supported\n",
|
||||
kctx->sealalg);
|
||||
goto out_err;
|
||||
}
|
||||
|
||||
blocksize = crypto_tfm_alg_blocksize(kctx->enc);
|
||||
gss_krb5_add_padding(buf, offset, blocksize);
|
||||
BUG_ON((buf->len - offset) % blocksize);
|
||||
plainlen = blocksize + buf->len - offset;
|
||||
|
||||
headlen = g_token_size(&kctx->mech_used, 22 + plainlen) -
|
||||
(buf->len - offset);
|
||||
|
||||
ptr = buf->head[0].iov_base + offset;
|
||||
/* shift data to make room for header. */
|
||||
/* XXX Would be cleverer to encrypt while copying. */
|
||||
/* XXX bounds checking, slack, etc. */
|
||||
memmove(ptr + headlen, ptr, buf->head[0].iov_len - offset);
|
||||
buf->head[0].iov_len += headlen;
|
||||
buf->len += headlen;
|
||||
BUG_ON((buf->len - offset - headlen) % blocksize);
|
||||
|
||||
g_make_token_header(&kctx->mech_used, 22 + plainlen, &ptr);
|
||||
|
||||
|
||||
*ptr++ = (unsigned char) ((KG_TOK_WRAP_MSG>>8)&0xff);
|
||||
*ptr++ = (unsigned char) (KG_TOK_WRAP_MSG&0xff);
|
||||
|
||||
/* ptr now at byte 2 of header described in rfc 1964, section 1.2.1: */
|
||||
krb5_hdr = ptr - 2;
|
||||
msg_start = krb5_hdr + 24;
|
||||
/* XXXJBF: */ BUG_ON(buf->head[0].iov_base + offset + headlen != msg_start + blocksize);
|
||||
|
||||
*(u16 *)(krb5_hdr + 2) = htons(kctx->signalg);
|
||||
memset(krb5_hdr + 4, 0xff, 4);
|
||||
*(u16 *)(krb5_hdr + 4) = htons(kctx->sealalg);
|
||||
|
||||
make_confounder(msg_start, blocksize);
|
||||
|
||||
/* XXXJBF: UGH!: */
|
||||
tmp_pages = buf->pages;
|
||||
buf->pages = pages;
|
||||
if (make_checksum(checksum_type, krb5_hdr, 8, buf,
|
||||
offset + headlen - blocksize, &md5cksum))
|
||||
goto out_err;
|
||||
buf->pages = tmp_pages;
|
||||
|
||||
switch (kctx->signalg) {
|
||||
case SGN_ALG_DES_MAC_MD5:
|
||||
if (krb5_encrypt(kctx->seq, NULL, md5cksum.data,
|
||||
md5cksum.data, md5cksum.len))
|
||||
goto out_err;
|
||||
memcpy(krb5_hdr + 16,
|
||||
md5cksum.data + md5cksum.len - KRB5_CKSUM_LENGTH,
|
||||
KRB5_CKSUM_LENGTH);
|
||||
|
||||
dprintk("RPC: make_seal_token: cksum data: \n");
|
||||
print_hexl((u32 *) (krb5_hdr + 16), KRB5_CKSUM_LENGTH, 0);
|
||||
break;
|
||||
default:
|
||||
BUG();
|
||||
}
|
||||
|
||||
kfree(md5cksum.data);
|
||||
|
||||
/* XXX would probably be more efficient to compute checksum
|
||||
* and encrypt at the same time: */
|
||||
if ((krb5_make_seq_num(kctx->seq, kctx->initiate ? 0 : 0xff,
|
||||
kctx->seq_send, krb5_hdr + 16, krb5_hdr + 8)))
|
||||
goto out_err;
|
||||
|
||||
if (gss_encrypt_xdr_buf(kctx->enc, buf, offset + headlen - blocksize,
|
||||
pages))
|
||||
goto out_err;
|
||||
|
||||
kctx->seq_send++;
|
||||
|
||||
return ((kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE);
|
||||
out_err:
|
||||
if (md5cksum.data) kfree(md5cksum.data);
|
||||
return GSS_S_FAILURE;
|
||||
}
|
||||
|
||||
u32
|
||||
gss_unwrap_kerberos(struct gss_ctx *ctx, u32 *qop, int offset,
|
||||
struct xdr_buf *buf)
|
||||
{
|
||||
struct krb5_ctx *kctx = ctx->internal_ctx_id;
|
||||
int signalg;
|
||||
int sealalg;
|
||||
s32 checksum_type;
|
||||
struct xdr_netobj md5cksum = {.len = 0, .data = NULL};
|
||||
s32 now;
|
||||
int direction;
|
||||
s32 seqnum;
|
||||
unsigned char *ptr;
|
||||
int bodysize;
|
||||
u32 ret = GSS_S_DEFECTIVE_TOKEN;
|
||||
void *data_start, *orig_start;
|
||||
int data_len;
|
||||
int blocksize;
|
||||
|
||||
dprintk("RPC: gss_unwrap_kerberos\n");
|
||||
|
||||
ptr = (u8 *)buf->head[0].iov_base + offset;
|
||||
if (g_verify_token_header(&kctx->mech_used, &bodysize, &ptr,
|
||||
buf->len - offset))
|
||||
goto out;
|
||||
|
||||
if ((*ptr++ != ((KG_TOK_WRAP_MSG>>8)&0xff)) ||
|
||||
(*ptr++ != (KG_TOK_WRAP_MSG &0xff)) )
|
||||
goto out;
|
||||
|
||||
/* XXX sanity-check bodysize?? */
|
||||
|
||||
/* get the sign and seal algorithms */
|
||||
|
||||
signalg = ptr[0] + (ptr[1] << 8);
|
||||
sealalg = ptr[2] + (ptr[3] << 8);
|
||||
|
||||
/* Sanity checks */
|
||||
|
||||
if ((ptr[4] != 0xff) || (ptr[5] != 0xff))
|
||||
goto out;
|
||||
|
||||
if (sealalg == 0xffff)
|
||||
goto out;
|
||||
|
||||
/* in the current spec, there is only one valid seal algorithm per
|
||||
key type, so a simple comparison is ok */
|
||||
|
||||
if (sealalg != kctx->sealalg)
|
||||
goto out;
|
||||
|
||||
/* there are several mappings of seal algorithms to sign algorithms,
|
||||
but few enough that we can try them all. */
|
||||
|
||||
if ((kctx->sealalg == SEAL_ALG_NONE && signalg > 1) ||
|
||||
(kctx->sealalg == SEAL_ALG_1 && signalg != SGN_ALG_3) ||
|
||||
(kctx->sealalg == SEAL_ALG_DES3KD &&
|
||||
signalg != SGN_ALG_HMAC_SHA1_DES3_KD))
|
||||
goto out;
|
||||
|
||||
if (gss_decrypt_xdr_buf(kctx->enc, buf,
|
||||
ptr + 22 - (unsigned char *)buf->head[0].iov_base))
|
||||
goto out;
|
||||
|
||||
/* compute the checksum of the message */
|
||||
|
||||
/* initialize the the cksum */
|
||||
switch (signalg) {
|
||||
case SGN_ALG_DES_MAC_MD5:
|
||||
checksum_type = CKSUMTYPE_RSA_MD5;
|
||||
break;
|
||||
default:
|
||||
ret = GSS_S_DEFECTIVE_TOKEN;
|
||||
goto out;
|
||||
}
|
||||
|
||||
switch (signalg) {
|
||||
case SGN_ALG_DES_MAC_MD5:
|
||||
ret = make_checksum(checksum_type, ptr - 2, 8, buf,
|
||||
ptr + 22 - (unsigned char *)buf->head[0].iov_base, &md5cksum);
|
||||
if (ret)
|
||||
goto out;
|
||||
|
||||
ret = krb5_encrypt(kctx->seq, NULL, md5cksum.data,
|
||||
md5cksum.data, md5cksum.len);
|
||||
if (ret)
|
||||
goto out;
|
||||
|
||||
if (memcmp(md5cksum.data + 8, ptr + 14, 8)) {
|
||||
ret = GSS_S_BAD_SIG;
|
||||
goto out;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
ret = GSS_S_DEFECTIVE_TOKEN;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* it got through unscathed. Make sure the context is unexpired */
|
||||
|
||||
if (qop)
|
||||
*qop = GSS_C_QOP_DEFAULT;
|
||||
|
||||
now = get_seconds();
|
||||
|
||||
ret = GSS_S_CONTEXT_EXPIRED;
|
||||
if (now > kctx->endtime)
|
||||
goto out;
|
||||
|
||||
/* do sequencing checks */
|
||||
|
||||
ret = GSS_S_BAD_SIG;
|
||||
if ((ret = krb5_get_seq_num(kctx->seq, ptr + 14, ptr + 6, &direction,
|
||||
&seqnum)))
|
||||
goto out;
|
||||
|
||||
if ((kctx->initiate && direction != 0xff) ||
|
||||
(!kctx->initiate && direction != 0))
|
||||
goto out;
|
||||
|
||||
/* Copy the data back to the right position. XXX: Would probably be
|
||||
* better to copy and encrypt at the same time. */
|
||||
|
||||
blocksize = crypto_tfm_alg_blocksize(kctx->enc);
|
||||
data_start = ptr + 22 + blocksize;
|
||||
orig_start = buf->head[0].iov_base + offset;
|
||||
data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start;
|
||||
memmove(orig_start, data_start, data_len);
|
||||
buf->head[0].iov_len -= (data_start - orig_start);
|
||||
buf->len -= (data_start - orig_start);
|
||||
|
||||
ret = GSS_S_DEFECTIVE_TOKEN;
|
||||
if (gss_krb5_remove_padding(buf, blocksize))
|
||||
goto out;
|
||||
|
||||
ret = GSS_S_COMPLETE;
|
||||
out:
|
||||
if (md5cksum.data) kfree(md5cksum.data);
|
||||
return ret;
|
||||
}
|
Loading…
Reference in a new issue