diff options
Diffstat (limited to '')
| -rw-r--r-- | net/rxrpc/key.c | 1245 |
1 files changed, 1245 insertions, 0 deletions
diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c new file mode 100644 index 000000000..979338a64 --- /dev/null +++ b/net/rxrpc/key.c @@ -0,0 +1,1245 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* RxRPC key management + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * RxRPC keys should have a description of describing their purpose: + * "afs@CAMBRIDGE.REDHAT.COM> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <crypto/skcipher.h> +#include <linux/module.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <linux/key-type.h> +#include <linux/ctype.h> +#include <linux/slab.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include <keys/rxrpc-type.h> +#include <keys/user-type.h> +#include "ar-internal.h" + +static int rxrpc_vet_description_s(const char *); +static int rxrpc_preparse(struct key_preparsed_payload *); +static int rxrpc_preparse_s(struct key_preparsed_payload *); +static void rxrpc_free_preparse(struct key_preparsed_payload *); +static void rxrpc_free_preparse_s(struct key_preparsed_payload *); +static void rxrpc_destroy(struct key *); +static void rxrpc_destroy_s(struct key *); +static void rxrpc_describe(const struct key *, struct seq_file *); +static long rxrpc_read(const struct key *, char *, size_t); + +/* + * rxrpc defined keys take an arbitrary string as the description and an + * arbitrary blob of data as the payload + */ +struct key_type key_type_rxrpc = { + .name = "rxrpc", + .flags = KEY_TYPE_NET_DOMAIN, + .preparse = rxrpc_preparse, + .free_preparse = rxrpc_free_preparse, + .instantiate = generic_key_instantiate, + .destroy = rxrpc_destroy, + .describe = rxrpc_describe, + .read = rxrpc_read, +}; +EXPORT_SYMBOL(key_type_rxrpc); + +/* + * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the + * description and an 8-byte decryption key as the payload + */ +struct key_type key_type_rxrpc_s = { + .name = "rxrpc_s", + .flags = KEY_TYPE_NET_DOMAIN, + .vet_description = rxrpc_vet_description_s, + .preparse = rxrpc_preparse_s, + .free_preparse = rxrpc_free_preparse_s, + .instantiate = generic_key_instantiate, + .destroy = rxrpc_destroy_s, + .describe = rxrpc_describe, +}; + +/* + * Vet the description for an RxRPC server key + */ +static int rxrpc_vet_description_s(const char *desc) +{ + unsigned long num; + char *p; + + num = simple_strtoul(desc, &p, 10); + if (*p != ':' || num > 65535) + return -EINVAL; + num = simple_strtoul(p + 1, &p, 10); + if (*p || num < 1 || num > 255) + return -EINVAL; + return 0; +} + +/* + * parse an RxKAD type XDR format token + * - the caller guarantees we have at least 4 words + */ +static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep, + size_t datalen, + const __be32 *xdr, unsigned int toklen) +{ + struct rxrpc_key_token *token, **pptoken; + time64_t expiry; + size_t plen; + u32 tktlen; + + _enter(",{%x,%x,%x,%x},%u", + ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]), + toklen); + + if (toklen <= 8 * 4) + return -EKEYREJECTED; + tktlen = ntohl(xdr[7]); + _debug("tktlen: %x", tktlen); + if (tktlen > AFSTOKEN_RK_TIX_MAX) + return -EKEYREJECTED; + if (toklen < 8 * 4 + tktlen) + return -EKEYREJECTED; + + plen = sizeof(*token) + sizeof(*token->kad) + tktlen; + prep->quotalen = datalen + plen; + + plen -= sizeof(*token); + token = kzalloc(sizeof(*token), GFP_KERNEL); + if (!token) + return -ENOMEM; + + token->kad = kzalloc(plen, GFP_KERNEL); + if (!token->kad) { + kfree(token); + return -ENOMEM; + } + + token->security_index = RXRPC_SECURITY_RXKAD; + token->kad->ticket_len = tktlen; + token->kad->vice_id = ntohl(xdr[0]); + token->kad->kvno = ntohl(xdr[1]); + token->kad->start = ntohl(xdr[4]); + token->kad->expiry = ntohl(xdr[5]); + token->kad->primary_flag = ntohl(xdr[6]); + memcpy(&token->kad->session_key, &xdr[2], 8); + memcpy(&token->kad->ticket, &xdr[8], tktlen); + + _debug("SCIX: %u", token->security_index); + _debug("TLEN: %u", token->kad->ticket_len); + _debug("EXPY: %x", token->kad->expiry); + _debug("KVNO: %u", token->kad->kvno); + _debug("PRIM: %u", token->kad->primary_flag); + _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x", + token->kad->session_key[0], token->kad->session_key[1], + token->kad->session_key[2], token->kad->session_key[3], + token->kad->session_key[4], token->kad->session_key[5], + token->kad->session_key[6], token->kad->session_key[7]); + if (token->kad->ticket_len >= 8) + _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x", + token->kad->ticket[0], token->kad->ticket[1], + token->kad->ticket[2], token->kad->ticket[3], + token->kad->ticket[4], token->kad->ticket[5], + token->kad->ticket[6], token->kad->ticket[7]); + + /* count the number of tokens attached */ + prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1); + + /* attach the data */ + for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0]; + *pptoken; + pptoken = &(*pptoken)->next) + continue; + *pptoken = token; + expiry = rxrpc_u32_to_time64(token->kad->expiry); + if (expiry < prep->expiry) + prep->expiry = expiry; + + _leave(" = 0"); + 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 int *_toklen) +{ + const __be32 *xdr = *_xdr; + unsigned int toklen = *_toklen, n_parts, loop, tmp, paddedlen; + + /* 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(n_parts, sizeof(char *), 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; + paddedlen = (tmp + 3) & ~3; + if (paddedlen > 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; + toklen -= paddedlen; + xdr += paddedlen >> 2; + } + + if (toklen < 4) + return -EINVAL; + tmp = ntohl(*xdr++); + toklen -= 4; + if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX) + return -EINVAL; + paddedlen = (tmp + 3) & ~3; + if (paddedlen > toklen) + return -EINVAL; + princ->realm = kmalloc(tmp + 1, GFP_KERNEL); + if (!princ->realm) + return -ENOMEM; + memcpy(princ->realm, xdr, tmp); + princ->realm[tmp] = 0; + toklen -= paddedlen; + xdr += paddedlen >> 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 int *_toklen) +{ + const __be32 *xdr = *_xdr; + unsigned int toklen = *_toklen, len, paddedlen; + + /* 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; + paddedlen = (len + 3) & ~3; + if (paddedlen > toklen) + return -EINVAL; + td->data_len = len; + + if (len > 0) { + td->data = kmemdup(xdr, len, GFP_KERNEL); + if (!td->data) + return -ENOMEM; + toklen -= paddedlen; + xdr += paddedlen >> 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 int *_toklen) +{ + struct krb5_tagged_data *td; + const __be32 *xdr = *_xdr; + unsigned int 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 > 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(n_elem, sizeof(struct krb5_tagged_data), + 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, u16 *_tktlen, + const __be32 **_xdr, unsigned int *_toklen) +{ + const __be32 *xdr = *_xdr; + unsigned int toklen = *_toklen, len, paddedlen; + + /* 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; + paddedlen = (len + 3) & ~3; + if (paddedlen > toklen) + return -EINVAL; + *_tktlen = len; + + _debug("ticket len %u", len); + + if (len > 0) { + *_ticket = kmemdup(xdr, len, GFP_KERNEL); + if (!*_ticket) + return -ENOMEM; + toklen -= paddedlen; + xdr += paddedlen >> 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_preparse_xdr_rxk5(struct key_preparsed_payload *prep, + size_t datalen, + const __be32 *xdr, unsigned int toklen) +{ + struct rxrpc_key_token *token, **pptoken; + struct rxk5_key *rxk5; + const __be32 *end_xdr = xdr + (toklen >> 2); + time64_t expiry; + 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 */ + prep->quotalen = datalen + toklen; + + 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 */ + for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0]; + *pptoken; + pptoken = &(*pptoken)->next) + continue; + *pptoken = token; + expiry = rxrpc_u32_to_time64(token->k5->endtime); + if (expiry < prep->expiry) + prep->expiry = 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 + */ +static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep) +{ + const __be32 *xdr = prep->data, *token; + const char *cp; + unsigned int len, paddedlen, loop, ntoken, toklen, sec_ix; + size_t datalen = prep->datalen; + int ret; + + _enter(",{%x,%x,%x,%x},%zu", + ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]), + prep->datalen); + + if (datalen > AFSTOKEN_LENGTH_MAX) + goto not_xdr; + + /* XDR is an array of __be32's */ + if (datalen & 3) + goto not_xdr; + + /* the flags should be 0 (the setpag bit must be handled by + * userspace) */ + if (ntohl(*xdr++) != 0) + goto not_xdr; + datalen -= 4; + + /* check the cell name */ + len = ntohl(*xdr++); + if (len < 1 || len > AFSTOKEN_CELL_MAX) + goto not_xdr; + datalen -= 4; + paddedlen = (len + 3) & ~3; + if (paddedlen > datalen) + goto not_xdr; + + cp = (const char *) xdr; + for (loop = 0; loop < len; loop++) + if (!isprint(cp[loop])) + goto not_xdr; + for (; loop < paddedlen; loop++) + if (cp[loop]) + goto not_xdr; + _debug("cellname: [%u/%u] '%*.*s'", + len, paddedlen, len, len, (const char *) xdr); + datalen -= paddedlen; + xdr += paddedlen >> 2; + + /* get the token count */ + if (datalen < 12) + goto not_xdr; + ntoken = ntohl(*xdr++); + datalen -= 4; + _debug("ntoken: %x", ntoken); + if (ntoken < 1 || ntoken > AFSTOKEN_MAX) + goto not_xdr; + + /* check each token wrapper */ + token = xdr; + loop = ntoken; + do { + if (datalen < 8) + goto not_xdr; + toklen = ntohl(*xdr++); + sec_ix = ntohl(*xdr); + datalen -= 4; + _debug("token: [%x/%zx] %x", toklen, datalen, sec_ix); + paddedlen = (toklen + 3) & ~3; + if (toklen < 20 || toklen > datalen || paddedlen > datalen) + goto not_xdr; + datalen -= paddedlen; + xdr += paddedlen >> 2; + + } while (--loop > 0); + + _debug("remainder: %zu", datalen); + if (datalen != 0) + goto not_xdr; + + /* okay: we're going to assume it's valid XDR format + * - we ignore the cellname, relying on the key to be correctly named + */ + do { + xdr = token; + toklen = ntohl(*xdr++); + token = xdr + ((toklen + 3) >> 2); + 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_preparse_xdr_rxkad(prep, datalen, xdr, toklen); + if (ret != 0) + goto error; + break; + + case RXRPC_SECURITY_RXK5: + ret = rxrpc_preparse_xdr_rxk5(prep, datalen, xdr, toklen); + if (ret != 0) + goto error; + break; + + default: + ret = -EPROTONOSUPPORT; + goto error; + } + + } while (--ntoken > 0); + + _leave(" = 0"); + return 0; + +not_xdr: + _leave(" = -EPROTO"); + return -EPROTO; +error: + _leave(" = %d", ret); + return ret; +} + +/* + * Preparse an rxrpc defined key. + * + * Data should be of the form: + * OFFSET LEN CONTENT + * 0 4 key interface version number + * 4 2 security index (type) + * 6 2 ticket length + * 8 4 key expiry time (time_t) + * 12 4 kvno + * 16 8 session key + * 24 [len] ticket + * + * if no data is provided, then a no-security key is made + */ +static int rxrpc_preparse(struct key_preparsed_payload *prep) +{ + const struct rxrpc_key_data_v1 *v1; + struct rxrpc_key_token *token, **pp; + time64_t expiry; + size_t plen; + u32 kver; + int ret; + + _enter("%zu", prep->datalen); + + /* handle a no-security key */ + if (!prep->data && prep->datalen == 0) + return 0; + + /* determine if the XDR payload format is being used */ + if (prep->datalen > 7 * 4) { + ret = rxrpc_preparse_xdr(prep); + if (ret != -EPROTO) + return ret; + } + + /* get the key interface version number */ + ret = -EINVAL; + if (prep->datalen <= 4 || !prep->data) + goto error; + memcpy(&kver, prep->data, sizeof(kver)); + prep->data += sizeof(kver); + prep->datalen -= sizeof(kver); + + _debug("KEY I/F VERSION: %u", kver); + + ret = -EKEYREJECTED; + if (kver != 1) + goto error; + + /* deal with a version 1 key */ + ret = -EINVAL; + if (prep->datalen < sizeof(*v1)) + goto error; + + v1 = prep->data; + if (prep->datalen != sizeof(*v1) + v1->ticket_length) + goto error; + + _debug("SCIX: %u", v1->security_index); + _debug("TLEN: %u", v1->ticket_length); + _debug("EXPY: %x", v1->expiry); + _debug("KVNO: %u", v1->kvno); + _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x", + v1->session_key[0], v1->session_key[1], + v1->session_key[2], v1->session_key[3], + v1->session_key[4], v1->session_key[5], + v1->session_key[6], v1->session_key[7]); + if (v1->ticket_length >= 8) + _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x", + v1->ticket[0], v1->ticket[1], + v1->ticket[2], v1->ticket[3], + v1->ticket[4], v1->ticket[5], + v1->ticket[6], v1->ticket[7]); + + ret = -EPROTONOSUPPORT; + if (v1->security_index != RXRPC_SECURITY_RXKAD) + goto error; + + plen = sizeof(*token->kad) + v1->ticket_length; + prep->quotalen = plen + sizeof(*token); + + ret = -ENOMEM; + token = kzalloc(sizeof(*token), GFP_KERNEL); + if (!token) + goto error; + token->kad = kzalloc(plen, GFP_KERNEL); + if (!token->kad) + goto error_free; + + token->security_index = RXRPC_SECURITY_RXKAD; + token->kad->ticket_len = v1->ticket_length; + token->kad->expiry = v1->expiry; + token->kad->kvno = v1->kvno; + memcpy(&token->kad->session_key, &v1->session_key, 8); + memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length); + + /* count the number of tokens attached */ + prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1); + + /* attach the data */ + pp = (struct rxrpc_key_token **)&prep->payload.data[0]; + while (*pp) + pp = &(*pp)->next; + *pp = token; + expiry = rxrpc_u32_to_time64(token->kad->expiry); + if (expiry < prep->expiry) + prep->expiry = expiry; + token = NULL; + ret = 0; + +error_free: + kfree(token); +error: + return ret; +} + +/* + * Free token list. + */ +static void rxrpc_free_token_list(struct rxrpc_key_token *token) +{ + struct rxrpc_key_token *next; + + for (; token; token = next) { + next = token->next; + switch (token->security_index) { + case RXRPC_SECURITY_RXKAD: + kfree(token->kad); + break; + case RXRPC_SECURITY_RXK5: + if (token->k5) + rxrpc_rxk5_free(token->k5); + break; + default: + pr_err("Unknown token type %x on rxrpc key\n", + token->security_index); + BUG(); + } + + kfree(token); + } +} + +/* + * Clean up preparse data. + */ +static void rxrpc_free_preparse(struct key_preparsed_payload *prep) +{ + rxrpc_free_token_list(prep->payload.data[0]); +} + +/* + * Preparse a server secret key. + * + * The data should be the 8-byte secret key. + */ +static int rxrpc_preparse_s(struct key_preparsed_payload *prep) +{ + struct crypto_skcipher *ci; + + _enter("%zu", prep->datalen); + + if (prep->datalen != 8) + return -EINVAL; + + memcpy(&prep->payload.data[2], prep->data, 8); + + ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(ci)) { + _leave(" = %ld", PTR_ERR(ci)); + return PTR_ERR(ci); + } + + if (crypto_skcipher_setkey(ci, prep->data, 8) < 0) + BUG(); + + prep->payload.data[0] = ci; + _leave(" = 0"); + return 0; +} + +/* + * Clean up preparse data. + */ +static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep) +{ + if (prep->payload.data[0]) + crypto_free_skcipher(prep->payload.data[0]); +} + +/* + * dispose of the data dangling from the corpse of a rxrpc key + */ +static void rxrpc_destroy(struct key *key) +{ + rxrpc_free_token_list(key->payload.data[0]); +} + +/* + * dispose of the data dangling from the corpse of a rxrpc key + */ +static void rxrpc_destroy_s(struct key *key) +{ + if (key->payload.data[0]) { + crypto_free_skcipher(key->payload.data[0]); + key->payload.data[0] = NULL; + } +} + +/* + * describe the rxrpc key + */ +static void rxrpc_describe(const struct key *key, struct seq_file *m) +{ + seq_puts(m, key->description); +} + +/* + * grab the security key for a socket + */ +int rxrpc_request_key(struct rxrpc_sock *rx, sockptr_t optval, int optlen) +{ + struct key *key; + char *description; + + _enter(""); + + if (optlen <= 0 || optlen > PAGE_SIZE - 1 || rx->securities) + return -EINVAL; + + description = memdup_sockptr_nul(optval, optlen); + if (IS_ERR(description)) + return PTR_ERR(description); + + key = request_key_net(&key_type_rxrpc, description, sock_net(&rx->sk), NULL); + if (IS_ERR(key)) { + kfree(description); + _leave(" = %ld", PTR_ERR(key)); + return PTR_ERR(key); + } + + rx->key = key; + kfree(description); + _leave(" = 0 [key %x]", key->serial); + return 0; +} + +/* + * grab the security keyring for a server socket + */ +int rxrpc_server_keyring(struct rxrpc_sock *rx, sockptr_t optval, int optlen) +{ + struct key *key; + char *description; + + _enter(""); + + if (optlen <= 0 || optlen > PAGE_SIZE - 1) + return -EINVAL; + + description = memdup_sockptr_nul(optval, optlen); + if (IS_ERR(description)) + return PTR_ERR(description); + + key = request_key(&key_type_keyring, description, NULL); + if (IS_ERR(key)) { + kfree(description); + _leave(" = %ld", PTR_ERR(key)); + return PTR_ERR(key); + } + + rx->securities = key; + kfree(description); + _leave(" = 0 [key %x]", key->serial); + return 0; +} + +/* + * generate a server data key + */ +int rxrpc_get_server_data_key(struct rxrpc_connection *conn, + const void *session_key, + time64_t expiry, + u32 kvno) +{ + const struct cred *cred = current_cred(); + struct key *key; + int ret; + + struct { + u32 kver; + struct rxrpc_key_data_v1 v1; + } data; + + _enter(""); + + key = key_alloc(&key_type_rxrpc, "x", + GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0, + KEY_ALLOC_NOT_IN_QUOTA, NULL); + if (IS_ERR(key)) { + _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key)); + return -ENOMEM; + } + + _debug("key %d", key_serial(key)); + + data.kver = 1; + data.v1.security_index = RXRPC_SECURITY_RXKAD; + data.v1.ticket_length = 0; + data.v1.expiry = rxrpc_time64_to_u32(expiry); + data.v1.kvno = 0; + + memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key)); + + ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL); + if (ret < 0) + goto error; + + conn->params.key = key; + _leave(" = 0 [%d]", key_serial(key)); + return 0; + +error: + key_revoke(key); + key_put(key); + _leave(" = -ENOMEM [ins %d]", ret); + return -ENOMEM; +} +EXPORT_SYMBOL(rxrpc_get_server_data_key); + +/** + * rxrpc_get_null_key - Generate a null RxRPC key + * @keyname: The name to give the key. + * + * Generate a null RxRPC key that can be used to indicate anonymous security is + * required for a particular domain. + */ +struct key *rxrpc_get_null_key(const char *keyname) +{ + const struct cred *cred = current_cred(); + struct key *key; + int ret; + + key = key_alloc(&key_type_rxrpc, keyname, + GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, + KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL); + if (IS_ERR(key)) + return key; + + ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL); + if (ret < 0) { + key_revoke(key); + key_put(key); + return ERR_PTR(ret); + } + + return key; +} +EXPORT_SYMBOL(rxrpc_get_null_key); + +/* + * read the contents of an rxrpc key + * - this returns the result in XDR form + */ +static long rxrpc_read(const struct key *key, + char *buffer, size_t buflen) +{ + const struct rxrpc_key_token *token; + const struct krb5_principal *princ; + size_t size; + __be32 *xdr, *oldxdr; + u32 cnlen, toksize, ntoks, tok, zero; + u16 toksizes[AFSTOKEN_MAX]; + int loop; + + _enter(""); + + /* we don't know what form we should return non-AFS keys in */ + if (memcmp(key->description, "afs@", 4) != 0) + 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 += RND(cnlen); /* cellname */ + size += 1 * 4; /* token count */ + + ntoks = 0; + for (token = key->payload.data[0]; token; token = token->next) { + toksize = 4; /* sec index */ + + switch (token->security_index) { + case RXRPC_SECURITY_RXKAD: + toksize += 8 * 4; /* viceid, kvno, key*2, begin, + * end, primary, tktlen */ + toksize += RND(token->kad->ticket_len); + break; + + 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 */ + pr_err("Unsupported key token type (%u)\n", + token->security_index); + return -ENOPKG; + } + + _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; + + xdr = (__be32 *)buffer; + zero = 0; +#define ENCODE(x) \ + do { \ + *xdr++ = htonl(x); \ + } while(0) +#define ENCODE_DATA(l, s) \ + do { \ + u32 _l = (l); \ + ENCODE(l); \ + memcpy(xdr, (s), _l); \ + if (_l & 3) \ + memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3)); \ + xdr += (_l + 3) >> 2; \ + } while(0) +#define ENCODE_BYTES(l, s) \ + do { \ + u32 _l = (l); \ + memcpy(xdr, (s), _l); \ + if (_l & 3) \ + memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3)); \ + xdr += (_l + 3) >> 2; \ + } while(0) +#define ENCODE64(x) \ + do { \ + __be64 y = cpu_to_be64(x); \ + memcpy(xdr, &y, 8); \ + 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_DATA(cnlen, key->description + 4); /* cellname */ + ENCODE(ntoks); + + tok = 0; + for (token = key->payload.data[0]; token; token = token->next) { + toksize = toksizes[tok++]; + ENCODE(toksize); + oldxdr = xdr; + ENCODE(token->security_index); + + switch (token->security_index) { + case RXRPC_SECURITY_RXKAD: + ENCODE(token->kad->vice_id); + ENCODE(token->kad->kvno); + ENCODE_BYTES(8, token->kad->session_key); + ENCODE(token->kad->start); + ENCODE(token->kad->expiry); + ENCODE(token->kad->primary_flag); + 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: + pr_err("Unsupported key token type (%u)\n", + token->security_index); + return -ENOPKG; + } + + 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; +} |