Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates from James Morris.

Mostly ima, selinux, smack and key handling updates.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits)
  integrity: do zero padding of the key id
  KEYS: output last portion of fingerprint in /proc/keys
  KEYS: strip 'id:' from ca_keyid
  KEYS: use swapped SKID for performing partial matching
  KEYS: Restore partial ID matching functionality for asymmetric keys
  X.509: If available, use the raw subjKeyId to form the key description
  KEYS: handle error code encoded in pointer
  selinux: normalize audit log formatting
  selinux: cleanup error reporting in selinux_nlmsg_perm()
  KEYS: Check hex2bin()'s return when generating an asymmetric key ID
  ima: detect violations for mmaped files
  ima: fix race condition on ima_rdwr_violation_check and process_measurement
  ima: added ima_policy_flag variable
  ima: return an error code from ima_add_boot_aggregate()
  ima: provide 'ima_appraise=log' kernel option
  ima: move keyring initialization to ima_init()
  PKCS#7: Handle PKCS#7 messages that contain no X.509 certs
  PKCS#7: Better handling of unsupported crypto
  KEYS: Overhaul key identification when searching for asymmetric keys
  KEYS: Implement binary asymmetric key ID handling
  ...
This commit is contained in:
Linus Torvalds 2014-10-12 10:13:55 -04:00
commit 5e40d331bd
67 changed files with 1593 additions and 865 deletions

View file

@ -9,9 +9,10 @@
* 2 of the Licence, or (at your option) any later version.
*/
int asymmetric_keyid_match(const char *kid, const char *id);
extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id);
static inline const char *asymmetric_key_id(const struct key *key)
static inline
const struct asymmetric_key_ids *asymmetric_key_ids(const struct key *key)
{
return key->type_data.p[1];
}

View file

@ -15,6 +15,7 @@
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include "asymmetric_keys.h"
MODULE_LICENSE("GPL");
@ -22,75 +23,197 @@ MODULE_LICENSE("GPL");
static LIST_HEAD(asymmetric_key_parsers);
static DECLARE_RWSEM(asymmetric_key_parsers_sem);
/*
* Match asymmetric key id with partial match
* @id: key id to match in a form "id:<id>"
*/
int asymmetric_keyid_match(const char *kid, const char *id)
{
size_t idlen, kidlen;
if (!kid || !id)
return 0;
/* make it possible to use id as in the request: "id:<id>" */
if (strncmp(id, "id:", 3) == 0)
id += 3;
/* Anything after here requires a partial match on the ID string */
idlen = strlen(id);
kidlen = strlen(kid);
if (idlen > kidlen)
return 0;
kid += kidlen - idlen;
if (strcasecmp(id, kid) != 0)
return 0;
return 1;
}
EXPORT_SYMBOL_GPL(asymmetric_keyid_match);
/*
* Match asymmetric keys on (part of) their name
* We have some shorthand methods for matching keys. We allow:
/**
* asymmetric_key_generate_id: Construct an asymmetric key ID
* @val_1: First binary blob
* @len_1: Length of first binary blob
* @val_2: Second binary blob
* @len_2: Length of second binary blob
*
* "<desc>" - request a key by description
* "id:<id>" - request a key matching the ID
* "<subtype>:<id>" - request a key of a subtype
* Construct an asymmetric key ID from a pair of binary blobs.
*/
static int asymmetric_key_match(const struct key *key, const void *description)
struct asymmetric_key_id *asymmetric_key_generate_id(const void *val_1,
size_t len_1,
const void *val_2,
size_t len_2)
{
const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
const char *spec = description;
struct asymmetric_key_id *kid;
kid = kmalloc(sizeof(struct asymmetric_key_id) + len_1 + len_2,
GFP_KERNEL);
if (!kid)
return ERR_PTR(-ENOMEM);
kid->len = len_1 + len_2;
memcpy(kid->data, val_1, len_1);
memcpy(kid->data + len_1, val_2, len_2);
return kid;
}
EXPORT_SYMBOL_GPL(asymmetric_key_generate_id);
/**
* asymmetric_key_id_same - Return true if two asymmetric keys IDs are the same.
* @kid_1, @kid_2: The key IDs to compare
*/
bool asymmetric_key_id_same(const struct asymmetric_key_id *kid1,
const struct asymmetric_key_id *kid2)
{
if (!kid1 || !kid2)
return false;
if (kid1->len != kid2->len)
return false;
return memcmp(kid1->data, kid2->data, kid1->len) == 0;
}
EXPORT_SYMBOL_GPL(asymmetric_key_id_same);
/**
* asymmetric_key_id_partial - Return true if two asymmetric keys IDs
* partially match
* @kid_1, @kid_2: The key IDs to compare
*/
bool asymmetric_key_id_partial(const struct asymmetric_key_id *kid1,
const struct asymmetric_key_id *kid2)
{
if (!kid1 || !kid2)
return false;
if (kid1->len < kid2->len)
return false;
return memcmp(kid1->data + (kid1->len - kid2->len),
kid2->data, kid2->len) == 0;
}
EXPORT_SYMBOL_GPL(asymmetric_key_id_partial);
/**
* asymmetric_match_key_ids - Search asymmetric key IDs
* @kids: The list of key IDs to check
* @match_id: The key ID we're looking for
* @match: The match function to use
*/
static bool asymmetric_match_key_ids(
const struct asymmetric_key_ids *kids,
const struct asymmetric_key_id *match_id,
bool (*match)(const struct asymmetric_key_id *kid1,
const struct asymmetric_key_id *kid2))
{
int i;
if (!kids || !match_id)
return false;
for (i = 0; i < ARRAY_SIZE(kids->id); i++)
if (match(kids->id[i], match_id))
return true;
return false;
}
/**
* asymmetric_key_hex_to_key_id - Convert a hex string into a key ID.
* @id: The ID as a hex string.
*/
struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id)
{
struct asymmetric_key_id *match_id;
size_t hexlen;
int ret;
if (!*id)
return ERR_PTR(-EINVAL);
hexlen = strlen(id);
if (hexlen & 1)
return ERR_PTR(-EINVAL);
match_id = kmalloc(sizeof(struct asymmetric_key_id) + hexlen / 2,
GFP_KERNEL);
if (!match_id)
return ERR_PTR(-ENOMEM);
match_id->len = hexlen / 2;
ret = hex2bin(match_id->data, id, hexlen / 2);
if (ret < 0) {
kfree(match_id);
return ERR_PTR(-EINVAL);
}
return match_id;
}
/*
* Match asymmetric keys by an exact match on an ID.
*/
static bool asymmetric_key_cmp(const struct key *key,
const struct key_match_data *match_data)
{
const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
const struct asymmetric_key_id *match_id = match_data->preparsed;
return asymmetric_match_key_ids(kids, match_id,
asymmetric_key_id_same);
}
/*
* Match asymmetric keys by a partial match on an IDs.
*/
static bool asymmetric_key_cmp_partial(const struct key *key,
const struct key_match_data *match_data)
{
const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
const struct asymmetric_key_id *match_id = match_data->preparsed;
return asymmetric_match_key_ids(kids, match_id,
asymmetric_key_id_partial);
}
/*
* Preparse the match criterion. If we don't set lookup_type and cmp,
* the default will be an exact match on the key description.
*
* There are some specifiers for matching key IDs rather than by the key
* description:
*
* "id:<id>" - find a key by partial match on any available ID
* "ex:<id>" - find a key by exact match on any available ID
*
* These have to be searched by iteration rather than by direct lookup because
* the key is hashed according to its description.
*/
static int asymmetric_key_match_preparse(struct key_match_data *match_data)
{
struct asymmetric_key_id *match_id;
const char *spec = match_data->raw_data;
const char *id;
ptrdiff_t speclen;
bool (*cmp)(const struct key *, const struct key_match_data *) =
asymmetric_key_cmp;
if (!subtype || !spec || !*spec)
return 0;
if (!spec || !*spec)
return -EINVAL;
if (spec[0] == 'i' &&
spec[1] == 'd' &&
spec[2] == ':') {
id = spec + 3;
cmp = asymmetric_key_cmp_partial;
} else if (spec[0] == 'e' &&
spec[1] == 'x' &&
spec[2] == ':') {
id = spec + 3;
} else {
goto default_match;
}
/* See if the full key description matches as is */
if (key->description && strcmp(key->description, description) == 0)
return 1;
/* All tests from here on break the criterion description into a
* specifier, a colon and then an identifier.
*/
id = strchr(spec, ':');
if (!id)
return 0;
speclen = id - spec;
id++;
if (speclen == 2 && memcmp(spec, "id", 2) == 0)
return asymmetric_keyid_match(asymmetric_key_id(key), id);
if (speclen == subtype->name_len &&
memcmp(spec, subtype->name, speclen) == 0)
return 1;
match_id = asymmetric_key_hex_to_key_id(id);
if (IS_ERR(match_id))
return PTR_ERR(match_id);
match_data->preparsed = match_id;
match_data->cmp = cmp;
match_data->lookup_type = KEYRING_SEARCH_LOOKUP_ITERATE;
return 0;
default_match:
return 0;
}
/*
* Free the preparsed the match criterion.
*/
static void asymmetric_key_match_free(struct key_match_data *match_data)
{
kfree(match_data->preparsed);
}
/*
@ -99,8 +222,10 @@ static int asymmetric_key_match(const struct key *key, const void *description)
static void asymmetric_key_describe(const struct key *key, struct seq_file *m)
{
const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
const char *kid = asymmetric_key_id(key);
size_t n;
const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
const struct asymmetric_key_id *kid;
const unsigned char *p;
int n;
seq_puts(m, key->description);
@ -108,13 +233,16 @@ static void asymmetric_key_describe(const struct key *key, struct seq_file *m)
seq_puts(m, ": ");
subtype->describe(key, m);
if (kid) {
if (kids && kids->id[1]) {
kid = kids->id[1];
seq_putc(m, ' ');
n = strlen(kid);
if (n <= 8)
seq_puts(m, kid);
else
seq_puts(m, kid + n - 8);
n = kid->len;
p = kid->data;
if (n > 4) {
p += n - 4;
n = 4;
}
seq_printf(m, "%*phN", n, p);
}
seq_puts(m, " [");
@ -165,6 +293,8 @@ static int asymmetric_key_preparse(struct key_preparsed_payload *prep)
static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep)
{
struct asymmetric_key_subtype *subtype = prep->type_data[0];
struct asymmetric_key_ids *kids = prep->type_data[1];
int i;
pr_devel("==>%s()\n", __func__);
@ -172,7 +302,11 @@ static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep)
subtype->destroy(prep->payload[0]);
module_put(subtype->owner);
}
kfree(prep->type_data[1]);
if (kids) {
for (i = 0; i < ARRAY_SIZE(kids->id); i++)
kfree(kids->id[i]);
kfree(kids);
}
kfree(prep->description);
}
@ -182,13 +316,20 @@ static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep)
static void asymmetric_key_destroy(struct key *key)
{
struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
struct asymmetric_key_ids *kids = key->type_data.p[1];
if (subtype) {
subtype->destroy(key->payload.data);
module_put(subtype->owner);
key->type_data.p[0] = NULL;
}
kfree(key->type_data.p[1]);
key->type_data.p[1] = NULL;
if (kids) {
kfree(kids->id[0]);
kfree(kids->id[1]);
kfree(kids);
key->type_data.p[1] = NULL;
}
}
struct key_type key_type_asymmetric = {
@ -196,10 +337,10 @@ struct key_type key_type_asymmetric = {
.preparse = asymmetric_key_preparse,
.free_preparse = asymmetric_key_free_preparse,
.instantiate = generic_key_instantiate,
.match = asymmetric_key_match,
.match_preparse = asymmetric_key_match_preparse,
.match_free = asymmetric_key_match_free,
.destroy = asymmetric_key_destroy,
.describe = asymmetric_key_describe,
.def_lookup_type = KEYRING_SEARCH_LOOKUP_ITERATE,
};
EXPORT_SYMBOL_GPL(key_type_asymmetric);

View file

@ -72,11 +72,9 @@ error:
*/
static struct key_type key_type_pkcs7 = {
.name = "pkcs7_test",
.def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
.preparse = pkcs7_preparse,
.free_preparse = user_free_preparse,
.instantiate = generic_key_instantiate,
.match = user_match,
.revoke = user_revoke,
.destroy = user_destroy,
.describe = user_describe,

View file

@ -29,8 +29,25 @@ struct pkcs7_parse_context {
enum OID last_oid; /* Last OID encountered */
unsigned x509_index;
unsigned sinfo_index;
const void *raw_serial;
unsigned raw_serial_size;
unsigned raw_issuer_size;
const void *raw_issuer;
};
/*
* Free a signed information block.
*/
static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
{
if (sinfo) {
mpi_free(sinfo->sig.mpi[0]);
kfree(sinfo->sig.digest);
kfree(sinfo->signing_cert_id);
kfree(sinfo);
}
}
/**
* pkcs7_free_message - Free a PKCS#7 message
* @pkcs7: The PKCS#7 message to free
@ -54,9 +71,7 @@ void pkcs7_free_message(struct pkcs7_message *pkcs7)
while (pkcs7->signed_infos) {
sinfo = pkcs7->signed_infos;
pkcs7->signed_infos = sinfo->next;
mpi_free(sinfo->sig.mpi[0]);
kfree(sinfo->sig.digest);
kfree(sinfo);
pkcs7_free_signed_info(sinfo);
}
kfree(pkcs7);
}
@ -71,51 +86,46 @@ EXPORT_SYMBOL_GPL(pkcs7_free_message);
struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
{
struct pkcs7_parse_context *ctx;
struct pkcs7_message *msg;
long ret;
struct pkcs7_message *msg = ERR_PTR(-ENOMEM);
int ret;
ret = -ENOMEM;
msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
if (!msg)
goto error_no_sig;
ctx = kzalloc(sizeof(struct pkcs7_parse_context), GFP_KERNEL);
if (!ctx)
goto error_no_ctx;
goto out_no_ctx;
ctx->msg = kzalloc(sizeof(struct pkcs7_message), GFP_KERNEL);
if (!ctx->msg)
goto out_no_msg;
ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
if (!ctx->sinfo)
goto error_no_sinfo;
goto out_no_sinfo;
ctx->msg = msg;
ctx->data = (unsigned long)data;
ctx->ppcerts = &ctx->certs;
ctx->ppsinfo = &ctx->msg->signed_infos;
/* Attempt to decode the signature */
ret = asn1_ber_decoder(&pkcs7_decoder, ctx, data, datalen);
if (ret < 0)
goto error_decode;
if (ret < 0) {
msg = ERR_PTR(ret);
goto out;
}
msg = ctx->msg;
ctx->msg = NULL;
out:
while (ctx->certs) {
struct x509_certificate *cert = ctx->certs;
ctx->certs = cert->next;
x509_free_certificate(cert);
}
mpi_free(ctx->sinfo->sig.mpi[0]);
kfree(ctx->sinfo->sig.digest);
kfree(ctx->sinfo);
pkcs7_free_signed_info(ctx->sinfo);
out_no_sinfo:
pkcs7_free_message(ctx->msg);
out_no_msg:
kfree(ctx);
out_no_ctx:
return msg;
error_decode:
mpi_free(ctx->sinfo->sig.mpi[0]);
kfree(ctx->sinfo->sig.digest);
kfree(ctx->sinfo);
error_no_sinfo:
kfree(ctx);
error_no_ctx:
pkcs7_free_message(msg);
error_no_sig:
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(pkcs7_parse_message);
@ -246,10 +256,10 @@ int pkcs7_extract_cert(void *context, size_t hdrlen,
if (IS_ERR(x509))
return PTR_ERR(x509);
pr_debug("Got cert for %s\n", x509->subject);
pr_debug("- fingerprint %s\n", x509->fingerprint);
x509->index = ++ctx->x509_index;
pr_debug("Got cert %u for %s\n", x509->index, x509->subject);
pr_debug("- fingerprint %*phN\n", x509->id->len, x509->id->data);
*ctx->ppcerts = x509;
ctx->ppcerts = &x509->next;
return 0;
@ -338,8 +348,8 @@ int pkcs7_sig_note_serial(void *context, size_t hdrlen,
const void *value, size_t vlen)
{
struct pkcs7_parse_context *ctx = context;
ctx->sinfo->raw_serial = value;
ctx->sinfo->raw_serial_size = vlen;
ctx->raw_serial = value;
ctx->raw_serial_size = vlen;
return 0;
}
@ -351,8 +361,8 @@ int pkcs7_sig_note_issuer(void *context, size_t hdrlen,
const void *value, size_t vlen)
{
struct pkcs7_parse_context *ctx = context;
ctx->sinfo->raw_issuer = value;
ctx->sinfo->raw_issuer_size = vlen;
ctx->raw_issuer = value;
ctx->raw_issuer_size = vlen;
return 0;
}
@ -385,10 +395,21 @@ int pkcs7_note_signed_info(void *context, size_t hdrlen,
const void *value, size_t vlen)
{
struct pkcs7_parse_context *ctx = context;
struct pkcs7_signed_info *sinfo = ctx->sinfo;
struct asymmetric_key_id *kid;
ctx->sinfo->index = ++ctx->sinfo_index;
*ctx->ppsinfo = ctx->sinfo;
ctx->ppsinfo = &ctx->sinfo->next;
/* Generate cert issuer + serial number key ID */
kid = asymmetric_key_generate_id(ctx->raw_serial,
ctx->raw_serial_size,
ctx->raw_issuer,
ctx->raw_issuer_size);
if (IS_ERR(kid))
return PTR_ERR(kid);
sinfo->signing_cert_id = kid;
sinfo->index = ++ctx->sinfo_index;
*ctx->ppsinfo = sinfo;
ctx->ppsinfo = &sinfo->next;
ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
if (!ctx->sinfo)
return -ENOMEM;

View file

@ -23,6 +23,7 @@ struct pkcs7_signed_info {
struct x509_certificate *signer; /* Signing certificate (in msg->certs) */
unsigned index;
bool trusted;
bool unsupported_crypto; /* T if not usable due to missing crypto */
/* Message digest - the digest of the Content Data (or NULL) */
const void *msgdigest;
@ -33,10 +34,7 @@ struct pkcs7_signed_info {
const void *authattrs;
/* Issuing cert serial number and issuer's name */
const void *raw_serial;
unsigned raw_serial_size;
unsigned raw_issuer_size;
const void *raw_issuer;
struct asymmetric_key_id *signing_cert_id;
/* Message signature.
*

View file

@ -23,9 +23,9 @@
/**
* Check the trust on one PKCS#7 SignedInfo block.
*/
int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
struct pkcs7_signed_info *sinfo,
struct key *trust_keyring)
static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
struct pkcs7_signed_info *sinfo,
struct key *trust_keyring)
{
struct public_key_signature *sig = &sinfo->sig;
struct x509_certificate *x509, *last = NULL, *p;
@ -35,6 +35,11 @@ int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
kenter(",%u,", sinfo->index);
if (sinfo->unsupported_crypto) {
kleave(" = -ENOPKG [cached]");
return -ENOPKG;
}
for (x509 = sinfo->signer; x509; x509 = x509->signer) {
if (x509->seen) {
if (x509->verified) {
@ -49,15 +54,18 @@ int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
/* Look to see if this certificate is present in the trusted
* keys.
*/
key = x509_request_asymmetric_key(trust_keyring, x509->subject,
x509->fingerprint);
if (!IS_ERR(key))
key = x509_request_asymmetric_key(trust_keyring, x509->id,
false);
if (!IS_ERR(key)) {
/* One of the X.509 certificates in the PKCS#7 message
* is apparently the same as one we already trust.
* Verify that the trusted variant can also validate
* the signature on the descendant.
*/
pr_devel("sinfo %u: Cert %u as key %x\n",
sinfo->index, x509->index, key_serial(key));
goto matched;
}
if (key == ERR_PTR(-ENOMEM))
return -ENOMEM;
@ -77,16 +85,36 @@ int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
/* No match - see if the root certificate has a signer amongst the
* trusted keys.
*/
if (!last || !last->issuer || !last->authority) {
kleave(" = -ENOKEY [no backref]");
return -ENOKEY;
if (last && last->authority) {
key = x509_request_asymmetric_key(trust_keyring, last->authority,
false);
if (!IS_ERR(key)) {
x509 = last;
pr_devel("sinfo %u: Root cert %u signer is key %x\n",
sinfo->index, x509->index, key_serial(key));
goto matched;
}
if (PTR_ERR(key) != -ENOKEY)
return PTR_ERR(key);
}
key = x509_request_asymmetric_key(trust_keyring, last->issuer,
last->authority);
if (IS_ERR(key))
return PTR_ERR(key) == -ENOMEM ? -ENOMEM : -ENOKEY;
x509 = last;
/* As a last resort, see if we have a trusted public key that matches
* the signed info directly.
*/
key = x509_request_asymmetric_key(trust_keyring,
sinfo->signing_cert_id,
false);
if (!IS_ERR(key)) {
pr_devel("sinfo %u: Direct signer is key %x\n",
sinfo->index, key_serial(key));
x509 = NULL;
goto matched;
}
if (PTR_ERR(key) != -ENOKEY)
return PTR_ERR(key);
kleave(" = -ENOKEY [no backref]");
return -ENOKEY;
matched:
ret = verify_signature(key, sig);
@ -100,10 +128,12 @@ matched:
}
verified:
x509->verified = true;
for (p = sinfo->signer; p != x509; p = p->signer) {
p->verified = true;
p->trusted = trusted;
if (x509) {
x509->verified = true;
for (p = sinfo->signer; p != x509; p = p->signer) {
p->verified = true;
p->trusted = trusted;
}
}
sinfo->trusted = trusted;
kleave(" = 0");
@ -141,24 +171,28 @@ int pkcs7_validate_trust(struct pkcs7_message *pkcs7,
{
struct pkcs7_signed_info *sinfo;
struct x509_certificate *p;
int cached_ret = 0, ret;
int cached_ret = -ENOKEY;
int ret;
for (p = pkcs7->certs; p; p = p->next)
p->seen = false;
for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
ret = pkcs7_validate_trust_one(pkcs7, sinfo, trust_keyring);
if (ret < 0) {
if (ret == -ENOPKG) {
switch (ret) {
case -ENOKEY:
continue;
case -ENOPKG:
if (cached_ret == -ENOKEY)
cached_ret = -ENOPKG;
} else if (ret == -ENOKEY) {
if (cached_ret == 0)
cached_ret = -ENOKEY;
} else {
return ret;
}
continue;
case 0:
*_trusted |= sinfo->trusted;
cached_ret = 0;
continue;
default:
return ret;
}
*_trusted |= sinfo->trusted;
}
return cached_ret;

View file

@ -131,8 +131,7 @@ static int pkcs7_find_key(struct pkcs7_message *pkcs7,
struct x509_certificate *x509;
unsigned certix = 1;
kenter("%u,%u,%u",
sinfo->index, sinfo->raw_serial_size, sinfo->raw_issuer_size);
kenter("%u", sinfo->index);
for (x509 = pkcs7->certs; x509; x509 = x509->next, certix++) {
/* I'm _assuming_ that the generator of the PKCS#7 message will
@ -140,21 +139,11 @@ static int pkcs7_find_key(struct pkcs7_message *pkcs7,
* PKCS#7 message - but I can't be 100% sure of that. It's
* possible this will need element-by-element comparison.
*/
if (x509->raw_serial_size != sinfo->raw_serial_size ||
memcmp(x509->raw_serial, sinfo->raw_serial,
sinfo->raw_serial_size) != 0)
if (!asymmetric_key_id_same(x509->id, sinfo->signing_cert_id))
continue;
pr_devel("Sig %u: Found cert serial match X.509[%u]\n",
sinfo->index, certix);
if (x509->raw_issuer_size != sinfo->raw_issuer_size ||
memcmp(x509->raw_issuer, sinfo->raw_issuer,
sinfo->raw_issuer_size) != 0) {
pr_warn("Sig %u: X.509 subject and PKCS#7 issuer don't match\n",
sinfo->index);
continue;
}
if (x509->pub->pkey_algo != sinfo->sig.pkey_algo) {
pr_warn("Sig %u: X.509 algo and PKCS#7 sig algo don't match\n",
sinfo->index);
@ -164,9 +153,14 @@ static int pkcs7_find_key(struct pkcs7_message *pkcs7,
sinfo->signer = x509;
return 0;
}
pr_warn("Sig %u: Issuing X.509 cert not found (#%*ph)\n",
sinfo->index, sinfo->raw_serial_size, sinfo->raw_serial);
return -ENOKEY;
/* The relevant X.509 cert isn't found here, but it might be found in
* the trust keyring.
*/
pr_debug("Sig %u: Issuing X.509 cert not found (#%*phN)\n",
sinfo->index,
sinfo->signing_cert_id->len, sinfo->signing_cert_id->data);
return 0;
}
/*
@ -184,15 +178,18 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
p->seen = false;
for (;;) {
pr_debug("verify %s: %s\n", x509->subject, x509->fingerprint);
pr_debug("verify %s: %*phN\n",
x509->subject,
x509->raw_serial_size, x509->raw_serial);
x509->seen = true;
ret = x509_get_sig_params(x509);
if (ret < 0)
return ret;
goto maybe_missing_crypto_in_x509;
pr_debug("- issuer %s\n", x509->issuer);
if (x509->authority)
pr_debug("- authkeyid %s\n", x509->authority);
pr_debug("- authkeyid %*phN\n",
x509->authority->len, x509->authority->data);
if (!x509->authority ||
strcmp(x509->subject, x509->issuer) == 0) {
@ -209,7 +206,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
ret = x509_check_signature(x509->pub, x509);
if (ret < 0)
return ret;
goto maybe_missing_crypto_in_x509;
x509->signer = x509;
pr_debug("- self-signed\n");
return 0;
@ -218,13 +215,14 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
/* Look through the X.509 certificates in the PKCS#7 message's
* list to see if the next one is there.
*/
pr_debug("- want %s\n", x509->authority);
pr_debug("- want %*phN\n",
x509->authority->len, x509->authority->data);
for (p = pkcs7->certs; p; p = p->next) {
pr_debug("- cmp [%u] %s\n", p->index, p->fingerprint);
if (p->raw_subject_size == x509->raw_issuer_size &&
strcmp(p->fingerprint, x509->authority) == 0 &&
memcmp(p->raw_subject, x509->raw_issuer,
x509->raw_issuer_size) == 0)
if (!p->skid)
continue;
pr_debug("- cmp [%u] %*phN\n",
p->index, p->skid->len, p->skid->data);
if (asymmetric_key_id_same(p->skid, x509->authority))
goto found_issuer;
}
@ -233,7 +231,7 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
return 0;
found_issuer:
pr_debug("- issuer %s\n", p->subject);
pr_debug("- subject %s\n", p->subject);
if (p->seen) {
pr_warn("Sig %u: X.509 chain contains loop\n",
sinfo->index);
@ -250,6 +248,17 @@ static int pkcs7_verify_sig_chain(struct pkcs7_message *pkcs7,
x509 = p;
might_sleep();
}
maybe_missing_crypto_in_x509:
/* Just prune the certificate chain at this point if we lack some
* crypto module to go further. Note, however, we don't want to set
* sinfo->missing_crypto as the signed info block may still be
* validatable against an X.509 cert lower in the chain that we have a
* trusted copy of.
*/
if (ret == -ENOPKG)
return 0;
return ret;
}
/*
@ -269,11 +278,14 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
if (ret < 0)
return ret;
/* Find the key for the signature */
/* Find the key for the signature if there is one */
ret = pkcs7_find_key(pkcs7, sinfo);
if (ret < 0)
return ret;
if (!sinfo->signer)
return 0;
pr_devel("Using X.509[%u] for sig %u\n",
sinfo->signer->index, sinfo->index);
@ -291,11 +303,33 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7,
/**
* pkcs7_verify - Verify a PKCS#7 message
* @pkcs7: The PKCS#7 message to be verified
*
* Verify a PKCS#7 message is internally consistent - that is, the data digest
* matches the digest in the AuthAttrs and any signature in the message or one
* of the X.509 certificates it carries that matches another X.509 cert in the
* message can be verified.
*
* This does not look to match the contents of the PKCS#7 message against any
* external public keys.
*
* Returns, in order of descending priority:
*
* (*) -EKEYREJECTED if a signature failed to match for which we found an
* appropriate X.509 certificate, or:
*
* (*) -EBADMSG if some part of the message was invalid, or:
*
* (*) -ENOPKG if none of the signature chains are verifiable because suitable
* crypto modules couldn't be found, or:
*
* (*) 0 if all the signature chains that don't incur -ENOPKG can be verified
* (note that a signature chain may be of zero length), or:
*/
int pkcs7_verify(struct pkcs7_message *pkcs7)
{
struct pkcs7_signed_info *sinfo;
struct x509_certificate *x509;
int enopkg = -ENOPKG;
int ret, n;
kenter("");
@ -304,18 +338,24 @@ int pkcs7_verify(struct pkcs7_message *pkcs7)
ret = x509_get_sig_params(x509);
if (ret < 0)
return ret;
pr_debug("X.509[%u] %s\n", n, x509->authority);
pr_debug("X.509[%u] %*phN\n",
n, x509->authority->len, x509->authority->data);
}
for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
ret = pkcs7_verify_one(pkcs7, sinfo);
if (ret < 0) {
if (ret == -ENOPKG) {
sinfo->unsupported_crypto = true;
continue;
}
kleave(" = %d", ret);
return ret;
}
enopkg = 0;
}
kleave(" = 0");
return 0;
kleave(" = %d", enopkg);
return enopkg;
}
EXPORT_SYMBOL_GPL(pkcs7_verify);

View file

@ -11,6 +11,7 @@
* 2 of the Licence, or (at your option) any later version.
*/
#define pr_fmt(fmt) "SIG: "fmt
#include <keys/asymmetric-subtype.h>
#include <linux/module.h>
#include <linux/err.h>

View file

@ -46,7 +46,8 @@ void x509_free_certificate(struct x509_certificate *cert)
public_key_destroy(cert->pub);
kfree(cert->issuer);
kfree(cert->subject);
kfree(cert->fingerprint);
kfree(cert->id);
kfree(cert->skid);
kfree(cert->authority);
kfree(cert->sig.digest);
mpi_free(cert->sig.rsa.s);
@ -62,6 +63,7 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
{
struct x509_certificate *cert;
struct x509_parse_context *ctx;
struct asymmetric_key_id *kid;
long ret;
ret = -ENOMEM;
@ -89,6 +91,17 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
if (ret < 0)
goto error_decode;
/* Generate cert issuer + serial number key ID */
kid = asymmetric_key_generate_id(cert->raw_serial,
cert->raw_serial_size,
cert->raw_issuer,
cert->raw_issuer_size);
if (IS_ERR(kid)) {
ret = PTR_ERR(kid);
goto error_decode;
}
cert->id = kid;
kfree(ctx);
return cert;
@ -407,36 +420,36 @@ int x509_process_extension(void *context, size_t hdrlen,
const void *value, size_t vlen)
{
struct x509_parse_context *ctx = context;
struct asymmetric_key_id *kid;
const unsigned char *v = value;
char *f;
int i;
pr_debug("Extension: %u\n", ctx->last_oid);
if (ctx->last_oid == OID_subjectKeyIdentifier) {
/* Get hold of the key fingerprint */
if (vlen < 3)
if (ctx->cert->skid || vlen < 3)
return -EBADMSG;
if (v[0] != ASN1_OTS || v[1] != vlen - 2)
return -EBADMSG;
v += 2;
vlen -= 2;
f = kmalloc(vlen * 2 + 1, GFP_KERNEL);
if (!f)
return -ENOMEM;
for (i = 0; i < vlen; i++)
sprintf(f + i * 2, "%02x", v[i]);
pr_debug("fingerprint %s\n", f);
ctx->cert->fingerprint = f;
ctx->cert->raw_skid_size = vlen;
ctx->cert->raw_skid = v;
kid = asymmetric_key_generate_id(ctx->cert->raw_subject,
ctx->cert->raw_subject_size,
v, vlen);
if (IS_ERR(kid))
return PTR_ERR(kid);
ctx->cert->skid = kid;
pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
return 0;
}
if (ctx->last_oid == OID_authorityKeyIdentifier) {
size_t key_len;
/* Get hold of the CA key fingerprint */
if (vlen < 5)
if (ctx->cert->authority || vlen < 5)
return -EBADMSG;
/* Authority Key Identifier must be a Constructed SEQUENCE */
@ -454,7 +467,7 @@ int x509_process_extension(void *context, size_t hdrlen,
v[3] > vlen - 4)
return -EBADMSG;
key_len = v[3];
vlen = v[3];
v += 4;
} else {
/* Long Form length */
@ -476,17 +489,17 @@ int x509_process_extension(void *context, size_t hdrlen,
v[sub + 1] > vlen - 4 - sub)
return -EBADMSG;
key_len = v[sub + 1];
vlen = v[sub + 1];
v += (sub + 2);
}
f = kmalloc(key_len * 2 + 1, GFP_KERNEL);
if (!f)
return -ENOMEM;
for (i = 0; i < key_len; i++)
sprintf(f + i * 2, "%02x", v[i]);
pr_debug("authority %s\n", f);
ctx->cert->authority = f;
kid = asymmetric_key_generate_id(ctx->cert->raw_issuer,
ctx->cert->raw_issuer_size,
v, vlen);
if (IS_ERR(kid))
return PTR_ERR(kid);
pr_debug("authkeyid %*phN\n", kid->len, kid->data);
ctx->cert->authority = kid;
return 0;
}

View file

@ -19,8 +19,9 @@ struct x509_certificate {
struct public_key_signature sig; /* Signature parameters */
char *issuer; /* Name of certificate issuer */
char *subject; /* Name of certificate subject */
char *fingerprint; /* Key fingerprint as hex */
char *authority; /* Authority key fingerprint as hex */
struct asymmetric_key_id *id; /* Serial number + issuer */
struct asymmetric_key_id *skid; /* Subject + subjectKeyId (optional) */
struct asymmetric_key_id *authority; /* Authority key identifier (optional) */
struct tm valid_from;
struct tm valid_to;
const void *tbs; /* Signed data */
@ -33,10 +34,13 @@ struct x509_certificate {
const void *raw_issuer; /* Raw issuer name in ASN.1 */
const void *raw_subject; /* Raw subject name in ASN.1 */
unsigned raw_subject_size;
unsigned raw_skid_size;
const void *raw_skid; /* Raw subjectKeyId in ASN.1 */
unsigned index;
bool seen; /* Infinite recursion prevention */
bool verified;
bool trusted;
bool unsupported_crypto; /* T if can't be verified due to missing crypto */
};
/*

View file

@ -25,7 +25,7 @@
#include "x509_parser.h"
static bool use_builtin_keys;
static char *ca_keyid;
static struct asymmetric_key_id *ca_keyid;
#ifndef MODULE
static int __init ca_keys_setup(char *str)
@ -33,10 +33,16 @@ static int __init ca_keys_setup(char *str)
if (!str) /* default system keyring */
return 1;
if (strncmp(str, "id:", 3) == 0)
ca_keyid = str; /* owner key 'id:xxxxxx' */
else if (strcmp(str, "builtin") == 0)
if (strncmp(str, "id:", 3) == 0) {
struct asymmetric_key_id *p;
p = asymmetric_key_hex_to_key_id(str + 3);
if (p == ERR_PTR(-EINVAL))
pr_err("Unparsable hex string in ca_keys\n");
else if (!IS_ERR(p))
ca_keyid = p; /* owner key 'id:xxxxxx' */
} else if (strcmp(str, "builtin") == 0) {
use_builtin_keys = true;
}
return 1;
}
@ -46,31 +52,35 @@ __setup("ca_keys=", ca_keys_setup);
/**
* x509_request_asymmetric_key - Request a key by X.509 certificate params.
* @keyring: The keys to search.
* @subject: The name of the subject to whom the key belongs.
* @key_id: The subject key ID as a hex string.
* @kid: The key ID.
* @partial: Use partial match if true, exact if false.
*
* Find a key in the given keyring by subject name and key ID. These might,
* for instance, be the issuer name and the authority key ID of an X.509
* certificate that needs to be verified.
*/
struct key *x509_request_asymmetric_key(struct key *keyring,
const char *subject,
const char *key_id)
const struct asymmetric_key_id *kid,
bool partial)
{
key_ref_t key;
size_t subject_len = strlen(subject), key_id_len = strlen(key_id);
char *id;
char *id, *p;
/* Construct an identifier "<subjname>:<keyid>". */
id = kmalloc(subject_len + 2 + key_id_len + 1, GFP_KERNEL);
/* Construct an identifier "id:<keyid>". */
p = id = kmalloc(2 + 1 + kid->len * 2 + 1, GFP_KERNEL);
if (!id)
return ERR_PTR(-ENOMEM);
memcpy(id, subject, subject_len);
id[subject_len + 0] = ':';
id[subject_len + 1] = ' ';
memcpy(id + subject_len + 2, key_id, key_id_len);
id[subject_len + 2 + key_id_len] = 0;
if (partial) {
*p++ = 'i';
*p++ = 'd';
} else {
*p++ = 'e';
*p++ = 'x';
}
*p++ = ':';
p = bin2hex(p, kid->data, kid->len);
*p = 0;
pr_debug("Look up: \"%s\"\n", id);
@ -112,6 +122,8 @@ int x509_get_sig_params(struct x509_certificate *cert)
pr_devel("==>%s()\n", __func__);
if (cert->unsupported_crypto)
return -ENOPKG;
if (cert->sig.rsa.s)
return 0;
@ -124,8 +136,13 @@ int x509_get_sig_params(struct x509_certificate *cert)
* big the hash operational data will be.
*/
tfm = crypto_alloc_shash(hash_algo_name[cert->sig.pkey_hash_algo], 0, 0);
if (IS_ERR(tfm))
return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm);
if (IS_ERR(tfm)) {
if (PTR_ERR(tfm) == -ENOENT) {
cert->unsupported_crypto = true;
return -ENOPKG;
}
return PTR_ERR(tfm);
}
desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
digest_size = crypto_shash_digestsize(tfm);
@ -172,6 +189,8 @@ int x509_check_signature(const struct public_key *pub,
return ret;
ret = public_key_verify_signature(pub, &cert->sig);
if (ret == -ENOPKG)
cert->unsupported_crypto = true;
pr_debug("Cert Verification: %d\n", ret);
return ret;
}
@ -195,11 +214,11 @@ static int x509_validate_trust(struct x509_certificate *cert,
if (!trust_keyring)
return -EOPNOTSUPP;
if (ca_keyid && !asymmetric_keyid_match(cert->authority, ca_keyid))
if (ca_keyid && !asymmetric_key_id_partial(cert->authority, ca_keyid))
return -EPERM;
key = x509_request_asymmetric_key(trust_keyring,
cert->issuer, cert->authority);
key = x509_request_asymmetric_key(trust_keyring, cert->authority,
false);
if (!IS_ERR(key)) {
if (!use_builtin_keys
|| test_bit(KEY_FLAG_BUILTIN, &key->flags))
@ -214,9 +233,11 @@ static int x509_validate_trust(struct x509_certificate *cert,
*/
static int x509_key_preparse(struct key_preparsed_payload *prep)
{
struct asymmetric_key_ids *kids;
struct x509_certificate *cert;
const char *q;
size_t srlen, sulen;
char *desc = NULL;
char *desc = NULL, *p;
int ret;
cert = x509_cert_parse(prep->data, prep->datalen);
@ -249,19 +270,12 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
pkey_algo_name[cert->sig.pkey_algo],
hash_algo_name[cert->sig.pkey_hash_algo]);
if (!cert->fingerprint) {
pr_warn("Cert for '%s' must have a SubjKeyId extension\n",
cert->subject);
ret = -EKEYREJECTED;
goto error_free_cert;
}
cert->pub->algo = pkey_algo[cert->pub->pkey_algo];
cert->pub->id_type = PKEY_ID_X509;
/* Check the signature on the key if it appears to be self-signed */
if (!cert->authority ||
strcmp(cert->fingerprint, cert->authority) == 0) {
asymmetric_key_id_same(cert->skid, cert->authority)) {
ret = x509_check_signature(cert->pub, cert); /* self-signed */
if (ret < 0)
goto error_free_cert;
@ -273,31 +287,52 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
/* Propose a description */
sulen = strlen(cert->subject);
srlen = strlen(cert->fingerprint);
if (cert->raw_skid) {
srlen = cert->raw_skid_size;
q = cert->raw_skid;
} else {
srlen = cert->raw_serial_size;
q = cert->raw_serial;
}
if (srlen > 1 && *q == 0) {
srlen--;
q++;
}
ret = -ENOMEM;
desc = kmalloc(sulen + 2 + srlen + 1, GFP_KERNEL);
desc = kmalloc(sulen + 2 + srlen * 2 + 1, GFP_KERNEL);
if (!desc)
goto error_free_cert;
memcpy(desc, cert->subject, sulen);
desc[sulen] = ':';
desc[sulen + 1] = ' ';
memcpy(desc + sulen + 2, cert->fingerprint, srlen);
desc[sulen + 2 + srlen] = 0;
p = memcpy(desc, cert->subject, sulen);
p += sulen;
*p++ = ':';
*p++ = ' ';
p = bin2hex(p, q, srlen);
*p = 0;
kids = kmalloc(sizeof(struct asymmetric_key_ids), GFP_KERNEL);
if (!kids)
goto error_free_desc;
kids->id[0] = cert->id;
kids->id[1] = cert->skid;
/* We're pinning the module by being linked against it */
__module_get(public_key_subtype.owner);
prep->type_data[0] = &public_key_subtype;
prep->type_data[1] = cert->fingerprint;
prep->type_data[1] = kids;
prep->payload[0] = cert->pub;
prep->description = desc;
prep->quotalen = 100;
/* We've finished with the certificate */
cert->pub = NULL;
cert->fingerprint = NULL;
cert->id = NULL;
cert->skid = NULL;
desc = NULL;
ret = 0;
error_free_desc:
kfree(desc);
error_free_cert:
x509_free_certificate(cert);
return ret;