RxRPC: Parse security index 5 keys (Kerberos 5)
Parse RxRPC security index 5 type keys (Kerberos 5 tokens).
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index bf4d623..44836f6 100644
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -64,7 +64,7 @@
static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
unsigned toklen)
{
- struct rxrpc_key_token *token;
+ struct rxrpc_key_token *token, **pptoken;
size_t plen;
u32 tktlen;
int ret;
@@ -129,8 +129,11 @@
key->type_data.x[0]++;
/* attach the data */
- token->next = key->payload.data;
- key->payload.data = token;
+ for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
+ *pptoken;
+ pptoken = &(*pptoken)->next)
+ continue;
+ *pptoken = token;
if (token->kad->expiry < key->expiry)
key->expiry = token->kad->expiry;
@@ -138,6 +141,388 @@
return 0;
}
+static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
+{
+ int loop;
+
+ if (princ->name_parts) {
+ for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
+ kfree(princ->name_parts[loop]);
+ kfree(princ->name_parts);
+ }
+ kfree(princ->realm);
+}
+
+static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
+{
+ kfree(td->data);
+}
+
+/*
+ * free up an RxK5 token
+ */
+static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
+{
+ int loop;
+
+ rxrpc_free_krb5_principal(&rxk5->client);
+ rxrpc_free_krb5_principal(&rxk5->server);
+ rxrpc_free_krb5_tagged(&rxk5->session);
+
+ if (rxk5->addresses) {
+ for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
+ rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
+ kfree(rxk5->addresses);
+ }
+ if (rxk5->authdata) {
+ for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
+ rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
+ kfree(rxk5->authdata);
+ }
+
+ kfree(rxk5->ticket);
+ kfree(rxk5->ticket2);
+ kfree(rxk5);
+}
+
+/*
+ * extract a krb5 principal
+ */
+static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
+ const __be32 **_xdr,
+ unsigned *_toklen)
+{
+ const __be32 *xdr = *_xdr;
+ unsigned toklen = *_toklen, n_parts, loop, tmp;
+
+ /* there must be at least one name, and at least #names+1 length
+ * words */
+ if (toklen <= 12)
+ return -EINVAL;
+
+ _enter(",{%x,%x,%x},%u",
+ ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
+
+ n_parts = ntohl(*xdr++);
+ toklen -= 4;
+ if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
+ return -EINVAL;
+ princ->n_name_parts = n_parts;
+
+ if (toklen <= (n_parts + 1) * 4)
+ return -EINVAL;
+
+ princ->name_parts = kcalloc(sizeof(char *), n_parts, GFP_KERNEL);
+ if (!princ->name_parts)
+ return -ENOMEM;
+
+ for (loop = 0; loop < n_parts; loop++) {
+ if (toklen < 4)
+ return -EINVAL;
+ tmp = ntohl(*xdr++);
+ toklen -= 4;
+ if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
+ return -EINVAL;
+ if (tmp > toklen)
+ return -EINVAL;
+ princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
+ if (!princ->name_parts[loop])
+ return -ENOMEM;
+ memcpy(princ->name_parts[loop], xdr, tmp);
+ princ->name_parts[loop][tmp] = 0;
+ tmp = (tmp + 3) & ~3;
+ toklen -= tmp;
+ xdr += tmp >> 2;
+ }
+
+ if (toklen < 4)
+ return -EINVAL;
+ tmp = ntohl(*xdr++);
+ toklen -= 4;
+ if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
+ return -EINVAL;
+ if (tmp > toklen)
+ return -EINVAL;
+ princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
+ if (!princ->realm)
+ return -ENOMEM;
+ memcpy(princ->realm, xdr, tmp);
+ princ->realm[tmp] = 0;
+ tmp = (tmp + 3) & ~3;
+ toklen -= tmp;
+ xdr += tmp >> 2;
+
+ _debug("%s/...@%s", princ->name_parts[0], princ->realm);
+
+ *_xdr = xdr;
+ *_toklen = toklen;
+ _leave(" = 0 [toklen=%u]", toklen);
+ return 0;
+}
+
+/*
+ * extract a piece of krb5 tagged data
+ */
+static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
+ size_t max_data_size,
+ const __be32 **_xdr,
+ unsigned *_toklen)
+{
+ const __be32 *xdr = *_xdr;
+ unsigned toklen = *_toklen, len;
+
+ /* there must be at least one tag and one length word */
+ if (toklen <= 8)
+ return -EINVAL;
+
+ _enter(",%zu,{%x,%x},%u",
+ max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
+
+ td->tag = ntohl(*xdr++);
+ len = ntohl(*xdr++);
+ toklen -= 8;
+ if (len > max_data_size)
+ return -EINVAL;
+ td->data_len = len;
+
+ if (len > 0) {
+ td->data = kmalloc(len, GFP_KERNEL);
+ if (!td->data)
+ return -ENOMEM;
+ memcpy(td->data, xdr, len);
+ len = (len + 3) & ~3;
+ toklen -= len;
+ xdr += len >> 2;
+ }
+
+ _debug("tag %x len %x", td->tag, td->data_len);
+
+ *_xdr = xdr;
+ *_toklen = toklen;
+ _leave(" = 0 [toklen=%u]", toklen);
+ return 0;
+}
+
+/*
+ * extract an array of tagged data
+ */
+static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
+ u8 *_n_elem,
+ u8 max_n_elem,
+ size_t max_elem_size,
+ const __be32 **_xdr,
+ unsigned *_toklen)
+{
+ struct krb5_tagged_data *td;
+ const __be32 *xdr = *_xdr;
+ unsigned toklen = *_toklen, n_elem, loop;
+ int ret;
+
+ /* there must be at least one count */
+ if (toklen < 4)
+ return -EINVAL;
+
+ _enter(",,%u,%zu,{%x},%u",
+ max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
+
+ n_elem = ntohl(*xdr++);
+ toklen -= 4;
+ if (n_elem < 0 || n_elem > max_n_elem)
+ return -EINVAL;
+ *_n_elem = n_elem;
+ if (n_elem > 0) {
+ if (toklen <= (n_elem + 1) * 4)
+ return -EINVAL;
+
+ _debug("n_elem %d", n_elem);
+
+ td = kcalloc(sizeof(struct krb5_tagged_data), n_elem,
+ GFP_KERNEL);
+ if (!td)
+ return -ENOMEM;
+ *_td = td;
+
+ for (loop = 0; loop < n_elem; loop++) {
+ ret = rxrpc_krb5_decode_tagged_data(&td[loop],
+ max_elem_size,
+ &xdr, &toklen);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ *_xdr = xdr;
+ *_toklen = toklen;
+ _leave(" = 0 [toklen=%u]", toklen);
+ return 0;
+}
+
+/*
+ * extract a krb5 ticket
+ */
+static int rxrpc_krb5_decode_ticket(u8 **_ticket, uint16_t *_tktlen,
+ const __be32 **_xdr, unsigned *_toklen)
+{
+ const __be32 *xdr = *_xdr;
+ unsigned toklen = *_toklen, len;
+
+ /* there must be at least one length word */
+ if (toklen <= 4)
+ return -EINVAL;
+
+ _enter(",{%x},%u", ntohl(xdr[0]), toklen);
+
+ len = ntohl(*xdr++);
+ toklen -= 4;
+ if (len > AFSTOKEN_K5_TIX_MAX)
+ return -EINVAL;
+ *_tktlen = len;
+
+ _debug("ticket len %u", len);
+
+ if (len > 0) {
+ *_ticket = kmalloc(len, GFP_KERNEL);
+ if (!*_ticket)
+ return -ENOMEM;
+ memcpy(*_ticket, xdr, len);
+ len = (len + 3) & ~3;
+ toklen -= len;
+ xdr += len >> 2;
+ }
+
+ *_xdr = xdr;
+ *_toklen = toklen;
+ _leave(" = 0 [toklen=%u]", toklen);
+ return 0;
+}
+
+/*
+ * parse an RxK5 type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_instantiate_xdr_rxk5(struct key *key, const __be32 *xdr,
+ unsigned toklen)
+{
+ struct rxrpc_key_token *token, **pptoken;
+ struct rxk5_key *rxk5;
+ const __be32 *end_xdr = xdr + (toklen >> 2);
+ int ret;
+
+ _enter(",{%x,%x,%x,%x},%u",
+ ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+ toklen);
+
+ /* reserve some payload space for this subkey - the length of the token
+ * is a reasonable approximation */
+ ret = key_payload_reserve(key, key->datalen + toklen);
+ if (ret < 0)
+ return ret;
+
+ token = kzalloc(sizeof(*token), GFP_KERNEL);
+ if (!token)
+ return -ENOMEM;
+
+ rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
+ if (!rxk5) {
+ kfree(token);
+ return -ENOMEM;
+ }
+
+ token->security_index = RXRPC_SECURITY_RXK5;
+ token->k5 = rxk5;
+
+ /* extract the principals */
+ ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
+ if (ret < 0)
+ goto error;
+ ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
+ if (ret < 0)
+ goto error;
+
+ /* extract the session key and the encoding type (the tag field ->
+ * ENCTYPE_xxx) */
+ ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
+ &xdr, &toklen);
+ if (ret < 0)
+ goto error;
+
+ if (toklen < 4 * 8 + 2 * 4)
+ goto inval;
+ rxk5->authtime = be64_to_cpup((const __be64 *) xdr);
+ xdr += 2;
+ rxk5->starttime = be64_to_cpup((const __be64 *) xdr);
+ xdr += 2;
+ rxk5->endtime = be64_to_cpup((const __be64 *) xdr);
+ xdr += 2;
+ rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
+ xdr += 2;
+ rxk5->is_skey = ntohl(*xdr++);
+ rxk5->flags = ntohl(*xdr++);
+ toklen -= 4 * 8 + 2 * 4;
+
+ _debug("times: a=%llx s=%llx e=%llx rt=%llx",
+ rxk5->authtime, rxk5->starttime, rxk5->endtime,
+ rxk5->renew_till);
+ _debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
+
+ /* extract the permitted client addresses */
+ ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
+ &rxk5->n_addresses,
+ AFSTOKEN_K5_ADDRESSES_MAX,
+ AFSTOKEN_DATA_MAX,
+ &xdr, &toklen);
+ if (ret < 0)
+ goto error;
+
+ ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+ /* extract the tickets */
+ ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
+ &xdr, &toklen);
+ if (ret < 0)
+ goto error;
+ ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
+ &xdr, &toklen);
+ if (ret < 0)
+ goto error;
+
+ ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+ /* extract the typed auth data */
+ ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
+ &rxk5->n_authdata,
+ AFSTOKEN_K5_AUTHDATA_MAX,
+ AFSTOKEN_BDATALN_MAX,
+ &xdr, &toklen);
+ if (ret < 0)
+ goto error;
+
+ ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+ if (toklen != 0)
+ goto inval;
+
+ /* attach the payload to the key */
+ for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
+ *pptoken;
+ pptoken = &(*pptoken)->next)
+ continue;
+ *pptoken = token;
+ if (token->kad->expiry < key->expiry)
+ key->expiry = token->kad->expiry;
+
+ _leave(" = 0");
+ return 0;
+
+inval:
+ ret = -EINVAL;
+error:
+ rxrpc_rxk5_free(rxk5);
+ kfree(token);
+ _leave(" = %d", ret);
+ return ret;
+}
+
/*
* attempt to parse the data as the XDR format
* - the caller guarantees we have more than 7 words
@@ -228,6 +613,8 @@
sec_ix = ntohl(*xdr++);
toklen -= 4;
+ _debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
+
switch (sec_ix) {
case RXRPC_SECURITY_RXKAD:
ret = rxrpc_instantiate_xdr_rxkad(key, xdr, toklen);
@@ -235,6 +622,12 @@
goto error;
break;
+ case RXRPC_SECURITY_RXK5:
+ ret = rxrpc_instantiate_xdr_rxk5(key, xdr, toklen);
+ if (ret != 0)
+ goto error;
+ break;
+
default:
ret = -EPROTONOSUPPORT;
goto error;
@@ -412,6 +805,10 @@
case RXRPC_SECURITY_RXKAD:
kfree(token->kad);
break;
+ case RXRPC_SECURITY_RXK5:
+ if (token->k5)
+ rxrpc_rxk5_free(token->k5);
+ break;
default:
printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
token->security_index);
@@ -602,10 +999,13 @@
static long rxrpc_read(const struct key *key,
char __user *buffer, size_t buflen)
{
- struct rxrpc_key_token *token;
- size_t size, toksize;
- __be32 __user *xdr;
- u32 cnlen, tktlen, ntoks, zero;
+ const struct rxrpc_key_token *token;
+ const struct krb5_principal *princ;
+ size_t size;
+ __be32 __user *xdr, *oldxdr;
+ u32 cnlen, toksize, ntoks, tok, zero;
+ u16 toksizes[AFSTOKEN_MAX];
+ int loop;
_enter("");
@@ -614,28 +1014,68 @@
return -EOPNOTSUPP;
cnlen = strlen(key->description + 4);
+#define RND(X) (((X) + 3) & ~3)
+
/* AFS keys we return in XDR form, so we need to work out the size of
* the XDR */
size = 2 * 4; /* flags, cellname len */
- size += (cnlen + 3) & ~3; /* cellname */
+ size += RND(cnlen); /* cellname */
size += 1 * 4; /* token count */
ntoks = 0;
for (token = key->payload.data; token; token = token->next) {
+ toksize = 4; /* sec index */
+
switch (token->security_index) {
case RXRPC_SECURITY_RXKAD:
- size += 2 * 4; /* length, security index (switch ID) */
- size += 8 * 4; /* viceid, kvno, key*2, begin, end,
- * primary, tktlen */
- size += (token->kad->ticket_len + 3) & ~3; /* ticket */
- ntoks++;
+ toksize += 8 * 4; /* viceid, kvno, key*2, begin,
+ * end, primary, tktlen */
+ toksize += RND(token->kad->ticket_len);
break;
- default: /* can't encode */
+ case RXRPC_SECURITY_RXK5:
+ princ = &token->k5->client;
+ toksize += 4 + princ->n_name_parts * 4;
+ for (loop = 0; loop < princ->n_name_parts; loop++)
+ toksize += RND(strlen(princ->name_parts[loop]));
+ toksize += 4 + RND(strlen(princ->realm));
+
+ princ = &token->k5->server;
+ toksize += 4 + princ->n_name_parts * 4;
+ for (loop = 0; loop < princ->n_name_parts; loop++)
+ toksize += RND(strlen(princ->name_parts[loop]));
+ toksize += 4 + RND(strlen(princ->realm));
+
+ toksize += 8 + RND(token->k5->session.data_len);
+
+ toksize += 4 * 8 + 2 * 4;
+
+ toksize += 4 + token->k5->n_addresses * 8;
+ for (loop = 0; loop < token->k5->n_addresses; loop++)
+ toksize += RND(token->k5->addresses[loop].data_len);
+
+ toksize += 4 + RND(token->k5->ticket_len);
+ toksize += 4 + RND(token->k5->ticket2_len);
+
+ toksize += 4 + token->k5->n_authdata * 8;
+ for (loop = 0; loop < token->k5->n_authdata; loop++)
+ toksize += RND(token->k5->authdata[loop].data_len);
break;
+
+ default: /* we have a ticket we can't encode */
+ BUG();
+ continue;
}
+
+ _debug("token[%u]: toksize=%u", ntoks, toksize);
+ ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
+
+ toksizes[ntoks++] = toksize;
+ size += toksize + 4; /* each token has a length word */
}
+#undef RND
+
if (!buffer || buflen < size)
return size;
@@ -647,52 +1087,109 @@
if (put_user(y, xdr++) < 0) \
goto fault; \
} while(0)
+#define ENCODE_DATA(l, s) \
+ do { \
+ u32 _l = (l); \
+ ENCODE(l); \
+ if (copy_to_user(xdr, (s), _l) != 0) \
+ goto fault; \
+ if (_l & 3 && \
+ copy_to_user((u8 *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
+ goto fault; \
+ xdr += (_l + 3) >> 2; \
+ } while(0)
+#define ENCODE64(x) \
+ do { \
+ __be64 y = cpu_to_be64(x); \
+ if (copy_to_user(xdr, &y, 8) != 0) \
+ goto fault; \
+ xdr += 8 >> 2; \
+ } while(0)
+#define ENCODE_STR(s) \
+ do { \
+ const char *_s = (s); \
+ ENCODE_DATA(strlen(_s), _s); \
+ } while(0)
- ENCODE(0); /* flags */
- ENCODE(cnlen); /* cellname length */
- if (copy_to_user(xdr, key->description + 4, cnlen) != 0)
- goto fault;
- if (cnlen & 3 &&
- copy_to_user((u8 *)xdr + cnlen, &zero, 4 - (cnlen & 3)) != 0)
- goto fault;
- xdr += (cnlen + 3) >> 2;
- ENCODE(ntoks); /* token count */
+ ENCODE(0); /* flags */
+ ENCODE_DATA(cnlen, key->description + 4); /* cellname */
+ ENCODE(ntoks);
+ tok = 0;
for (token = key->payload.data; token; token = token->next) {
- toksize = 1 * 4; /* sec index */
+ toksize = toksizes[tok++];
+ ENCODE(toksize);
+ oldxdr = xdr;
+ ENCODE(token->security_index);
switch (token->security_index) {
case RXRPC_SECURITY_RXKAD:
- toksize += 8 * 4;
- toksize += (token->kad->ticket_len + 3) & ~3;
- ENCODE(toksize);
- ENCODE(token->security_index);
ENCODE(token->kad->vice_id);
ENCODE(token->kad->kvno);
- if (copy_to_user(xdr, token->kad->session_key, 8) != 0)
- goto fault;
- xdr += 8 >> 2;
+ ENCODE_DATA(8, token->kad->session_key);
ENCODE(token->kad->start);
ENCODE(token->kad->expiry);
ENCODE(token->kad->primary_flag);
- tktlen = token->kad->ticket_len;
- ENCODE(tktlen);
- if (copy_to_user(xdr, token->kad->ticket, tktlen) != 0)
- goto fault;
- if (tktlen & 3 &&
- copy_to_user((u8 *)xdr + tktlen, &zero,
- 4 - (tktlen & 3)) != 0)
- goto fault;
- xdr += (tktlen + 3) >> 2;
+ ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
+ break;
+
+ case RXRPC_SECURITY_RXK5:
+ princ = &token->k5->client;
+ ENCODE(princ->n_name_parts);
+ for (loop = 0; loop < princ->n_name_parts; loop++)
+ ENCODE_STR(princ->name_parts[loop]);
+ ENCODE_STR(princ->realm);
+
+ princ = &token->k5->server;
+ ENCODE(princ->n_name_parts);
+ for (loop = 0; loop < princ->n_name_parts; loop++)
+ ENCODE_STR(princ->name_parts[loop]);
+ ENCODE_STR(princ->realm);
+
+ ENCODE(token->k5->session.tag);
+ ENCODE_DATA(token->k5->session.data_len,
+ token->k5->session.data);
+
+ ENCODE64(token->k5->authtime);
+ ENCODE64(token->k5->starttime);
+ ENCODE64(token->k5->endtime);
+ ENCODE64(token->k5->renew_till);
+ ENCODE(token->k5->is_skey);
+ ENCODE(token->k5->flags);
+
+ ENCODE(token->k5->n_addresses);
+ for (loop = 0; loop < token->k5->n_addresses; loop++) {
+ ENCODE(token->k5->addresses[loop].tag);
+ ENCODE_DATA(token->k5->addresses[loop].data_len,
+ token->k5->addresses[loop].data);
+ }
+
+ ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
+ ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
+
+ ENCODE(token->k5->n_authdata);
+ for (loop = 0; loop < token->k5->n_authdata; loop++) {
+ ENCODE(token->k5->authdata[loop].tag);
+ ENCODE_DATA(token->k5->authdata[loop].data_len,
+ token->k5->authdata[loop].data);
+ }
break;
default:
+ BUG();
break;
}
+
+ ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
+ toksize);
}
+#undef ENCODE_STR
+#undef ENCODE_DATA
+#undef ENCODE64
#undef ENCODE
+ ASSERTCMP(tok, ==, ntoks);
ASSERTCMP((char __user *) xdr - buffer, ==, size);
_leave(" = %zu", size);
return size;