From 775d395f8bd8ef08971c77f54c38ec7b9355ba4f Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:15:10 +0100
Subject: [PATCH 01/18] KEYS: Rename public key parameter name arrays
Rename the arrays of public key parameters (public key algorithm names, hash
algorithm names and ID type names) so that the array name ends in "_name".
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
---
crypto/asymmetric_keys/public_key.c | 14 +++++++-------
crypto/asymmetric_keys/x509_public_key.c | 8 ++++----
include/crypto/public_key.h | 6 +++---
kernel/module_signing.c | 4 ++--
4 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index cb2e291..b313df1 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -22,13 +22,13 @@
MODULE_LICENSE("GPL");
-const char *const pkey_algo[PKEY_ALGO__LAST] = {
+const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
[PKEY_ALGO_DSA] = "DSA",
[PKEY_ALGO_RSA] = "RSA",
};
-EXPORT_SYMBOL_GPL(pkey_algo);
+EXPORT_SYMBOL_GPL(pkey_algo_name);
-const char *const pkey_hash_algo[PKEY_HASH__LAST] = {
+const char *const pkey_hash_algo_name[PKEY_HASH__LAST] = {
[PKEY_HASH_MD4] = "md4",
[PKEY_HASH_MD5] = "md5",
[PKEY_HASH_SHA1] = "sha1",
@@ -38,13 +38,13 @@ const char *const pkey_hash_algo[PKEY_HASH__LAST] = {
[PKEY_HASH_SHA512] = "sha512",
[PKEY_HASH_SHA224] = "sha224",
};
-EXPORT_SYMBOL_GPL(pkey_hash_algo);
+EXPORT_SYMBOL_GPL(pkey_hash_algo_name);
-const char *const pkey_id_type[PKEY_ID_TYPE__LAST] = {
+const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = {
[PKEY_ID_PGP] = "PGP",
[PKEY_ID_X509] = "X509",
};
-EXPORT_SYMBOL_GPL(pkey_id_type);
+EXPORT_SYMBOL_GPL(pkey_id_type_name);
/*
* Provide a part of a description of the key for /proc/keys.
@@ -56,7 +56,7 @@ static void public_key_describe(const struct key *asymmetric_key,
if (key)
seq_printf(m, "%s.%s",
- pkey_id_type[key->id_type], key->algo->name);
+ pkey_id_type_name[key->id_type], key->algo->name);
}
/*
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 06007f0..afbbc36 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -49,7 +49,7 @@ static int x509_check_signature(const struct public_key *pub,
/* Allocate the hashing algorithm we're going to need and find out how
* big the hash operational data will be.
*/
- tfm = crypto_alloc_shash(pkey_hash_algo[cert->sig_hash_algo], 0, 0);
+ tfm = crypto_alloc_shash(pkey_hash_algo_name[cert->sig_hash_algo], 0, 0);
if (IS_ERR(tfm))
return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm);
@@ -117,7 +117,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
pr_devel("Cert Issuer: %s\n", cert->issuer);
pr_devel("Cert Subject: %s\n", cert->subject);
- pr_devel("Cert Key Algo: %s\n", pkey_algo[cert->pkey_algo]);
+ pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pkey_algo]);
pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n",
cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1,
cert->valid_from.tm_mday, cert->valid_from.tm_hour,
@@ -127,8 +127,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
cert->valid_to.tm_mday, cert->valid_to.tm_hour,
cert->valid_to.tm_min, cert->valid_to.tm_sec);
pr_devel("Cert Signature: %s + %s\n",
- pkey_algo[cert->sig_pkey_algo],
- pkey_hash_algo[cert->sig_hash_algo]);
+ pkey_algo_name[cert->sig_pkey_algo],
+ pkey_hash_algo_name[cert->sig_hash_algo]);
if (!cert->fingerprint || !cert->authority) {
pr_warn("Cert for '%s' must have SubjKeyId and AuthKeyId extensions\n",
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index f5b0224..619d570 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -22,7 +22,7 @@ enum pkey_algo {
PKEY_ALGO__LAST
};
-extern const char *const pkey_algo[PKEY_ALGO__LAST];
+extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
enum pkey_hash_algo {
PKEY_HASH_MD4,
@@ -36,7 +36,7 @@ enum pkey_hash_algo {
PKEY_HASH__LAST
};
-extern const char *const pkey_hash_algo[PKEY_HASH__LAST];
+extern const char *const pkey_hash_algo_name[PKEY_HASH__LAST];
enum pkey_id_type {
PKEY_ID_PGP, /* OpenPGP generated key ID */
@@ -44,7 +44,7 @@ enum pkey_id_type {
PKEY_ID_TYPE__LAST
};
-extern const char *const pkey_id_type[PKEY_ID_TYPE__LAST];
+extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];
/*
* Cryptographic data for the public-key subtype of the asymmetric key type.
diff --git a/kernel/module_signing.c b/kernel/module_signing.c
index f2970bd..ee47640 100644
--- a/kernel/module_signing.c
+++ b/kernel/module_signing.c
@@ -54,7 +54,7 @@ static struct public_key_signature *mod_make_digest(enum pkey_hash_algo hash,
/* Allocate the hashing algorithm we're going to need and find out how
* big the hash operational data will be.
*/
- tfm = crypto_alloc_shash(pkey_hash_algo[hash], 0, 0);
+ tfm = crypto_alloc_shash(pkey_hash_algo_name[hash], 0, 0);
if (IS_ERR(tfm))
return (PTR_ERR(tfm) == -ENOENT) ? ERR_PTR(-ENOPKG) : ERR_CAST(tfm);
@@ -217,7 +217,7 @@ int mod_verify_sig(const void *mod, unsigned long *_modlen)
return -ENOPKG;
if (ms.hash >= PKEY_HASH__LAST ||
- !pkey_hash_algo[ms.hash])
+ !pkey_hash_algo_name[ms.hash])
return -ENOPKG;
key = request_asymmetric_key(sig, ms.signer_len,
--
1.8.3.1
From d12f06db05dacb455714f00f070cce844fb3e44c Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:15:18 +0100
Subject: [PATCH 02/18] KEYS: Move the algorithm pointer array from x509 to
public_key.c
Move the public-key algorithm pointer array from x509_public_key.c to
public_key.c as it isn't X.509 specific.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
---
crypto/asymmetric_keys/public_key.c | 8 ++++++++
crypto/asymmetric_keys/x509_public_key.c | 11 +----------
include/crypto/public_key.h | 1 +
3 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index b313df1..796ce08 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -28,6 +28,14 @@ const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
};
EXPORT_SYMBOL_GPL(pkey_algo_name);
+const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST] = {
+#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \
+ defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE)
+ [PKEY_ALGO_RSA] = &RSA_public_key_algorithm,
+#endif
+};
+EXPORT_SYMBOL_GPL(pkey_algo);
+
const char *const pkey_hash_algo_name[PKEY_HASH__LAST] = {
[PKEY_HASH_MD4] = "md4",
[PKEY_HASH_MD5] = "md5",
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index afbbc36..fe38628 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -23,15 +23,6 @@
#include "public_key.h"
#include "x509_parser.h"
-static const
-struct public_key_algorithm *x509_public_key_algorithms[PKEY_ALGO__LAST] = {
- [PKEY_ALGO_DSA] = NULL,
-#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \
- defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE)
- [PKEY_ALGO_RSA] = &RSA_public_key_algorithm,
-#endif
-};
-
/*
* Check the signature on a certificate using the provided public key
*/
@@ -174,7 +165,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
goto error_free_cert;
}
- cert->pub->algo = x509_public_key_algorithms[cert->pkey_algo];
+ cert->pub->algo = pkey_algo[cert->pkey_algo];
cert->pub->id_type = PKEY_ID_X509;
/* Check the signature on the key */
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 619d570..46bde25 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -23,6 +23,7 @@ enum pkey_algo {
};
extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
+extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];
enum pkey_hash_algo {
PKEY_HASH_MD4,
--
1.8.3.1
From 8d2905bce58b356e9b5313a4aaebb5085bb4c151 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:15:24 +0100
Subject: [PATCH 03/18] KEYS: Store public key algo ID in public_key struct
Store public key algo ID in public_key struct for reference purposes. This
allows it to be removed from the x509_certificate struct and used to find a
default in public_key_verify_signature().
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
---
crypto/asymmetric_keys/x509_cert_parser.c | 5 +++--
crypto/asymmetric_keys/x509_parser.h | 1 -
crypto/asymmetric_keys/x509_public_key.c | 4 ++--
include/crypto/public_key.h | 1 +
4 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index facbf26..8cc253d 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -343,8 +343,9 @@ int x509_extract_key_data(void *context, size_t hdrlen,
if (ctx->last_oid != OID_rsaEncryption)
return -ENOPKG;
- /* There seems to be an extraneous 0 byte on the front of the data */
- ctx->cert->pkey_algo = PKEY_ALGO_RSA;
+ ctx->cert->pub->pkey_algo = PKEY_ALGO_RSA;
+
+ /* Discard the BIT STRING metadata */
ctx->key = value + 1;
ctx->key_size = vlen - 1;
return 0;
diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h
index f86dc5f..e583ad0 100644
--- a/crypto/asymmetric_keys/x509_parser.h
+++ b/crypto/asymmetric_keys/x509_parser.h
@@ -20,7 +20,6 @@ struct x509_certificate {
char *authority; /* Authority key fingerprint as hex */
struct tm valid_from;
struct tm valid_to;
- enum pkey_algo pkey_algo : 8; /* Public key algorithm */
enum pkey_algo sig_pkey_algo : 8; /* Signature public key algorithm */
enum pkey_hash_algo sig_hash_algo : 8; /* Signature hash algorithm */
const void *tbs; /* Signed data */
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index fe38628..fac574c 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -108,7 +108,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
pr_devel("Cert Issuer: %s\n", cert->issuer);
pr_devel("Cert Subject: %s\n", cert->subject);
- pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pkey_algo]);
+ pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pub->pkey_algo]);
pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n",
cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1,
cert->valid_from.tm_mday, cert->valid_from.tm_hour,
@@ -165,7 +165,7 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
goto error_free_cert;
}
- cert->pub->algo = pkey_algo[cert->pkey_algo];
+ cert->pub->algo = pkey_algo[cert->pub->pkey_algo];
cert->pub->id_type = PKEY_ID_X509;
/* Check the signature on the key */
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 46bde25..05778df 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -60,6 +60,7 @@ struct public_key {
#define PKEY_CAN_DECRYPT 0x02
#define PKEY_CAN_SIGN 0x04
#define PKEY_CAN_VERIFY 0x08
+ enum pkey_algo pkey_algo : 8;
enum pkey_id_type id_type : 8;
union {
MPI mpi[5];
--
1.8.3.1
From df1662a5b9f37a88c1e112d4052eca79efc8e6fc Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:15:30 +0100
Subject: [PATCH 04/18] KEYS: Split public_key_verify_signature() and make
available
Modify public_key_verify_signature() so that it now takes a public_key struct
rather than a key struct and supply a wrapper that takes a key struct. The
wrapper is then used by the asymmetric key subtype and the modified function is
used by X.509 self-signature checking and can be used by other things also.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
---
crypto/asymmetric_keys/public_key.c | 40 +++++++++++++++++++++++++-------
crypto/asymmetric_keys/public_key.h | 6 +++++
crypto/asymmetric_keys/x509_public_key.c | 2 +-
3 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index 796ce08..49ac8d8 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -86,21 +86,45 @@ EXPORT_SYMBOL_GPL(public_key_destroy);
/*
* Verify a signature using a public key.
*/
-static int public_key_verify_signature(const struct key *key,
- const struct public_key_signature *sig)
+int public_key_verify_signature(const struct public_key *pk,
+ const struct public_key_signature *sig)
{
- const struct public_key *pk = key->payload.data;
+ const struct public_key_algorithm *algo;
+
+ BUG_ON(!pk);
+ BUG_ON(!pk->mpi[0]);
+ BUG_ON(!pk->mpi[1]);
+ BUG_ON(!sig);
+ BUG_ON(!sig->digest);
+ BUG_ON(!sig->mpi[0]);
+
+ algo = pk->algo;
+ if (!algo) {
+ if (pk->pkey_algo >= PKEY_ALGO__LAST)
+ return -ENOPKG;
+ algo = pkey_algo[pk->pkey_algo];
+ if (!algo)
+ return -ENOPKG;
+ }
- if (!pk->algo->verify_signature)
+ if (!algo->verify_signature)
return -ENOTSUPP;
- if (sig->nr_mpi != pk->algo->n_sig_mpi) {
+ if (sig->nr_mpi != algo->n_sig_mpi) {
pr_debug("Signature has %u MPI not %u\n",
- sig->nr_mpi, pk->algo->n_sig_mpi);
+ sig->nr_mpi, algo->n_sig_mpi);
return -EINVAL;
}
- return pk->algo->verify_signature(pk, sig);
+ return algo->verify_signature(pk, sig);
+}
+EXPORT_SYMBOL_GPL(public_key_verify_signature);
+
+static int public_key_verify_signature_2(const struct key *key,
+ const struct public_key_signature *sig)
+{
+ const struct public_key *pk = key->payload.data;
+ return public_key_verify_signature(pk, sig);
}
/*
@@ -111,6 +135,6 @@ struct asymmetric_key_subtype public_key_subtype = {
.name = "public_key",
.describe = public_key_describe,
.destroy = public_key_destroy,
- .verify_signature = public_key_verify_signature,
+ .verify_signature = public_key_verify_signature_2,
};
EXPORT_SYMBOL_GPL(public_key_subtype);
diff --git a/crypto/asymmetric_keys/public_key.h b/crypto/asymmetric_keys/public_key.h
index 5e5e356..5c37a22 100644
--- a/crypto/asymmetric_keys/public_key.h
+++ b/crypto/asymmetric_keys/public_key.h
@@ -28,3 +28,9 @@ struct public_key_algorithm {
};
extern const struct public_key_algorithm RSA_public_key_algorithm;
+
+/*
+ * public_key.c
+ */
+extern int public_key_verify_signature(const struct public_key *pk,
+ const struct public_key_signature *sig);
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index fac574c..8cb2f70 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -76,7 +76,7 @@ static int x509_check_signature(const struct public_key *pub,
if (ret < 0)
goto error_mpi;
- ret = pub->algo->verify_signature(pub, sig);
+ ret = public_key_verify_signature(pub, sig);
pr_debug("Cert Verification: %d\n", ret);
--
1.8.3.1
From 322d3b7e2debb3c7983dce2b80a5aefa4e7b1bda Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:15:37 +0100
Subject: [PATCH 05/18] KEYS: Store public key algo ID in public_key_signature
struct
Store public key algorithm ID in public_key_signature struct for reference
purposes. This allows a public_key_signature struct to be embedded in
struct x509_certificate and other places more easily.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
---
include/crypto/public_key.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 05778df..b34fda4 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -90,6 +90,7 @@ struct public_key_signature {
u8 *digest;
u8 digest_size; /* Number of bytes in digest */
u8 nr_mpi; /* Occupancy of mpi[] */
+ enum pkey_algo pkey_algo : 8;
enum pkey_hash_algo pkey_hash_algo : 8;
union {
MPI mpi[2];
--
1.8.3.1
From 743143dd12661df376dcfc916b626b01d8ec84a4 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:16:34 +0100
Subject: [PATCH 06/18] X.509: struct x509_certificate needs struct tm
declaring
struct x509_certificate needs struct tm declaring by #inclusion of linux/time.h
prior to its definition.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
---
crypto/asymmetric_keys/x509_parser.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h
index e583ad0..2d01182 100644
--- a/crypto/asymmetric_keys/x509_parser.h
+++ b/crypto/asymmetric_keys/x509_parser.h
@@ -9,6 +9,7 @@
* 2 of the Licence, or (at your option) any later version.
*/
+#include <linux/time.h>
#include <crypto/public_key.h>
struct x509_certificate {
--
1.8.3.1
From a326ca89468c73dacb00fa247e92873d09e1387b Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:18:02 +0100
Subject: [PATCH 07/18] X.509: Embed public_key_signature struct and create
filler function
Embed a public_key_signature struct in struct x509_certificate, eliminating
now unnecessary fields, and split x509_check_signature() to create a filler
function for it that attaches a digest of the signed data and an MPI that
represents the signature data. x509_free_certificate() is then modified to
deal with these.
Whilst we're at it, export both x509_check_signature() and the new
x509_get_sig_params().
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
---
crypto/asymmetric_keys/x509_cert_parser.c | 30 +++++------
crypto/asymmetric_keys/x509_parser.h | 16 ++++--
crypto/asymmetric_keys/x509_public_key.c | 83 +++++++++++++++++--------------
3 files changed, 74 insertions(+), 55 deletions(-)
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
index 8cc253d..144201c 100644
--- a/crypto/asymmetric_keys/x509_cert_parser.c
+++ b/crypto/asymmetric_keys/x509_cert_parser.c
@@ -47,6 +47,8 @@ void x509_free_certificate(struct x509_certificate *cert)
kfree(cert->subject);
kfree(cert->fingerprint);
kfree(cert->authority);
+ kfree(cert->sig.digest);
+ mpi_free(cert->sig.rsa.s);
kfree(cert);
}
}
@@ -152,33 +154,33 @@ int x509_note_pkey_algo(void *context, size_t hdrlen,
return -ENOPKG; /* Unsupported combination */
case OID_md4WithRSAEncryption:
- ctx->cert->sig_hash_algo = PKEY_HASH_MD5;
- ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA;
+ ctx->cert->sig.pkey_hash_algo = PKEY_HASH_MD5;
+ ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
break;
case OID_sha1WithRSAEncryption:
- ctx->cert->sig_hash_algo = PKEY_HASH_SHA1;
- ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA;
+ ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA1;
+ ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
break;
case OID_sha256WithRSAEncryption:
- ctx->cert->sig_hash_algo = PKEY_HASH_SHA256;
- ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA;
+ ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA256;
+ ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
break;
case OID_sha384WithRSAEncryption:
- ctx->cert->sig_hash_algo = PKEY_HASH_SHA384;
- ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA;
+ ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA384;
+ ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
break;
case OID_sha512WithRSAEncryption:
- ctx->cert->sig_hash_algo = PKEY_HASH_SHA512;
- ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA;
+ ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA512;
+ ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
break;
case OID_sha224WithRSAEncryption:
- ctx->cert->sig_hash_algo = PKEY_HASH_SHA224;
- ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA;
+ ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA224;
+ ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA;
break;
}
@@ -203,8 +205,8 @@ int x509_note_signature(void *context, size_t hdrlen,
return -EINVAL;
}
- ctx->cert->sig = value;
- ctx->cert->sig_size = vlen;
+ ctx->cert->raw_sig = value;
+ ctx->cert->raw_sig_size = vlen;
return 0;
}
diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h
index 2d01182..87d9cc2 100644
--- a/crypto/asymmetric_keys/x509_parser.h
+++ b/crypto/asymmetric_keys/x509_parser.h
@@ -21,12 +21,11 @@ struct x509_certificate {
char *authority; /* Authority key fingerprint as hex */
struct tm valid_from;
struct tm valid_to;
- enum pkey_algo sig_pkey_algo : 8; /* Signature public key algorithm */
- enum pkey_hash_algo sig_hash_algo : 8; /* Signature hash algorithm */
const void *tbs; /* Signed data */
- size_t tbs_size; /* Size of signed data */
- const void *sig; /* Signature data */
- size_t sig_size; /* Size of sigature */
+ unsigned tbs_size; /* Size of signed data */
+ unsigned raw_sig_size; /* Size of sigature */
+ const void *raw_sig; /* Signature data */
+ struct public_key_signature sig; /* Signature parameters */
};
/*
@@ -34,3 +33,10 @@ struct x509_certificate {
*/
extern void x509_free_certificate(struct x509_certificate *cert);
extern struct x509_certificate *x509_cert_parse(const void *data, size_t datalen);
+
+/*
+ * x509_public_key.c
+ */
+extern int x509_get_sig_params(struct x509_certificate *cert);
+extern int x509_check_signature(const struct public_key *pub,
+ struct x509_certificate *cert);
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 8cb2f70..b7c81d8 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -24,72 +24,83 @@
#include "x509_parser.h"
/*
- * Check the signature on a certificate using the provided public key
+ * Set up the signature parameters in an X.509 certificate. This involves
+ * digesting the signed data and extracting the signature.
*/
-static int x509_check_signature(const struct public_key *pub,
- const struct x509_certificate *cert)
+int x509_get_sig_params(struct x509_certificate *cert)
{
- struct public_key_signature *sig;
struct crypto_shash *tfm;
struct shash_desc *desc;
size_t digest_size, desc_size;
+ void *digest;
int ret;
pr_devel("==>%s()\n", __func__);
-
+
+ if (cert->sig.rsa.s)
+ return 0;
+
+ cert->sig.rsa.s = mpi_read_raw_data(cert->raw_sig, cert->raw_sig_size);
+ if (!cert->sig.rsa.s)
+ return -ENOMEM;
+ cert->sig.nr_mpi = 1;
+
/* Allocate the hashing algorithm we're going to need and find out how
* big the hash operational data will be.
*/
- tfm = crypto_alloc_shash(pkey_hash_algo_name[cert->sig_hash_algo], 0, 0);
+ tfm = crypto_alloc_shash(pkey_hash_algo_name[cert->sig.pkey_hash_algo], 0, 0);
if (IS_ERR(tfm))
return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm);
desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
digest_size = crypto_shash_digestsize(tfm);
- /* We allocate the hash operational data storage on the end of our
- * context data.
+ /* We allocate the hash operational data storage on the end of the
+ * digest storage space.
*/
ret = -ENOMEM;
- sig = kzalloc(sizeof(*sig) + desc_size + digest_size, GFP_KERNEL);
- if (!sig)
- goto error_no_sig;
+ digest = kzalloc(digest_size + desc_size, GFP_KERNEL);
+ if (!digest)
+ goto error;
- sig->pkey_hash_algo = cert->sig_hash_algo;
- sig->digest = (u8 *)sig + sizeof(*sig) + desc_size;
- sig->digest_size = digest_size;
+ cert->sig.digest = digest;
+ cert->sig.digest_size = digest_size;
- desc = (void *)sig + sizeof(*sig);
- desc->tfm = tfm;
- desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+ desc = digest + digest_size;
+ desc->tfm = tfm;
+ desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
ret = crypto_shash_init(desc);
if (ret < 0)
goto error;
+ might_sleep();
+ ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, digest);
+error:
+ crypto_free_shash(tfm);
+ pr_devel("<==%s() = %d\n", __func__, ret);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(x509_get_sig_params);
- ret = -ENOMEM;
- sig->rsa.s = mpi_read_raw_data(cert->sig, cert->sig_size);
- if (!sig->rsa.s)
- goto error;
+/*
+ * Check the signature on a certificate using the provided public key
+ */
+int x509_check_signature(const struct public_key *pub,
+ struct x509_certificate *cert)
+{
+ int ret;
- ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, sig->digest);
- if (ret < 0)
- goto error_mpi;
+ pr_devel("==>%s()\n", __func__);
- ret = public_key_verify_signature(pub, sig);
+ ret = x509_get_sig_params(cert);
+ if (ret < 0)
+ return ret;
+ ret = public_key_verify_signature(pub, &cert->sig);
pr_debug("Cert Verification: %d\n", ret);
-
-error_mpi:
- mpi_free(sig->rsa.s);
-error:
- kfree(sig);
-error_no_sig:
- crypto_free_shash(tfm);
-
- pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
}
+EXPORT_SYMBOL_GPL(x509_check_signature);
/*
* Attempt to parse a data blob for a key as an X509 certificate.
@@ -118,8 +129,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
cert->valid_to.tm_mday, cert->valid_to.tm_hour,
cert->valid_to.tm_min, cert->valid_to.tm_sec);
pr_devel("Cert Signature: %s + %s\n",
- pkey_algo_name[cert->sig_pkey_algo],
- pkey_hash_algo_name[cert->sig_hash_algo]);
+ pkey_algo_name[cert->sig.pkey_algo],
+ pkey_hash_algo_name[cert->sig.pkey_hash_algo]);
if (!cert->fingerprint || !cert->authority) {
pr_warn("Cert for '%s' must have SubjKeyId and AuthKeyId extensions\n",
--
1.8.3.1
From 2857db9154b0fcfb8ba490c12f98cd47cc3f46fc Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:18:15 +0100
Subject: [PATCH 08/18] X.509: Check the algorithm IDs obtained from parsing an
X.509 certificate
Check that the algorithm IDs obtained from the ASN.1 parse by OID lookup
corresponds to algorithms that are available to us.
Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Howells <dhowells@redhat.com>
---
crypto/asymmetric_keys/x509_public_key.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index b7c81d8..eb368d4 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -119,6 +119,17 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
pr_devel("Cert Issuer: %s\n", cert->issuer);
pr_devel("Cert Subject: %s\n", cert->subject);
+
+ if (cert->pub->pkey_algo >= PKEY_ALGO__LAST ||
+ cert->sig.pkey_algo >= PKEY_ALGO__LAST ||
+ cert->sig.pkey_hash_algo >= PKEY_HASH__LAST ||
+ !pkey_algo[cert->pub->pkey_algo] ||
+ !pkey_algo[cert->sig.pkey_algo] ||
+ !pkey_hash_algo_name[cert->sig.pkey_hash_algo]) {
+ ret = -ENOPKG;
+ goto error_free_cert;
+ }
+
pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pub->pkey_algo]);
pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n",
cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1,
--
1.8.3.1
From f78f0e8694517a3b1e5393d6ea0d46084bdc816a Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:18:31 +0100
Subject: [PATCH 09/18] X.509: Handle certificates that lack an
authorityKeyIdentifier field
Handle certificates that lack an authorityKeyIdentifier field by assuming
they're self-signed and checking their signatures against themselves.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
---
crypto/asymmetric_keys/x509_public_key.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index eb368d4..0f55e3b 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -143,8 +143,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
pkey_algo_name[cert->sig.pkey_algo],
pkey_hash_algo_name[cert->sig.pkey_hash_algo]);
- if (!cert->fingerprint || !cert->authority) {
- pr_warn("Cert for '%s' must have SubjKeyId and AuthKeyId extensions\n",
+ if (!cert->fingerprint) {
+ pr_warn("Cert for '%s' must have a SubjKeyId extension\n",
cert->subject);
ret = -EKEYREJECTED;
goto error_free_cert;
@@ -190,8 +190,9 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
cert->pub->algo = pkey_algo[cert->pub->pkey_algo];
cert->pub->id_type = PKEY_ID_X509;
- /* Check the signature on the key */
- if (strcmp(cert->fingerprint, cert->authority) == 0) {
+ /* Check the signature on the key if it appears to be self-signed */
+ if (!cert->authority ||
+ strcmp(cert->fingerprint, cert->authority) == 0) {
ret = x509_check_signature(cert->pub, cert);
if (ret < 0)
goto error_free_cert;
--
1.8.3.1
From 4d729ace6be1c3b2b5d9b0d0301a4ffd342ec74a Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Tue, 18 Jun 2013 17:40:44 +0100
Subject: [PATCH 10/18] X.509: Remove certificate date checks
Remove the certificate date checks that are performed when a certificate is
parsed. There are two checks: a valid from and a valid to. The first check is
causing a lot of problems with system clocks that don't keep good time and the
second places an implicit expiry date upon the kernel when used for module
signing, so do we really need them?
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Rusty Russell <rusty@rustcorp.com.au>
cc: Josh Boyer <jwboyer@redhat.com>
cc: Alexander Holler <holler@ahsoftware.de>
cc: stable@vger.kernel.org
---
crypto/asymmetric_keys/x509_public_key.c | 38 --------------------------------
1 file changed, 38 deletions(-)
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 0f55e3b..c1540e8 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -108,7 +108,6 @@ EXPORT_SYMBOL_GPL(x509_check_signature);
static int x509_key_preparse(struct key_preparsed_payload *prep)
{
struct x509_certificate *cert;
- struct tm now;
size_t srlen, sulen;
char *desc = NULL;
int ret;
@@ -150,43 +149,6 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
goto error_free_cert;
}
- time_to_tm(CURRENT_TIME.tv_sec, 0, &now);
- pr_devel("Now: %04ld-%02d-%02d %02d:%02d:%02d\n",
- now.tm_year + 1900, now.tm_mon + 1, now.tm_mday,
- now.tm_hour, now.tm_min, now.tm_sec);
- if (now.tm_year < cert->valid_from.tm_year ||
- (now.tm_year == cert->valid_from.tm_year &&
- (now.tm_mon < cert->valid_from.tm_mon ||
- (now.tm_mon == cert->valid_from.tm_mon &&
- (now.tm_mday < cert->valid_from.tm_mday ||
- (now.tm_mday == cert->valid_from.tm_mday &&
- (now.tm_hour < cert->valid_from.tm_hour ||
- (now.tm_hour == cert->valid_from.tm_hour &&
- (now.tm_min < cert->valid_from.tm_min ||
- (now.tm_min == cert->valid_from.tm_min &&
- (now.tm_sec < cert->valid_from.tm_sec
- ))))))))))) {
- pr_warn("Cert %s is not yet valid\n", cert->fingerprint);
- ret = -EKEYREJECTED;
- goto error_free_cert;
- }
- if (now.tm_year > cert->valid_to.tm_year ||
- (now.tm_year == cert->valid_to.tm_year &&
- (now.tm_mon > cert->valid_to.tm_mon ||
- (now.tm_mon == cert->valid_to.tm_mon &&
- (now.tm_mday > cert->valid_to.tm_mday ||
- (now.tm_mday == cert->valid_to.tm_mday &&
- (now.tm_hour > cert->valid_to.tm_hour ||
- (now.tm_hour == cert->valid_to.tm_hour &&
- (now.tm_min > cert->valid_to.tm_min ||
- (now.tm_min == cert->valid_to.tm_min &&
- (now.tm_sec > cert->valid_to.tm_sec
- ))))))))))) {
- pr_warn("Cert %s has expired\n", cert->fingerprint);
- ret = -EKEYEXPIRED;
- goto error_free_cert;
- }
-
cert->pub->algo = pkey_algo[cert->pub->pkey_algo];
cert->pub->id_type = PKEY_ID_X509;
--
1.8.3.1
From 33f859fea67ab5307da4049e947fbc23cdd13a27 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:07:13 +0100
Subject: [PATCH 11/18] KEYS: Load *.x509 files into kernel keyring
Load all the files matching the pattern "*.x509" that are to be found in kernel
base source dir and base build dir into the module signing keyring.
The "extra_certificates" file is then redundant.
Signed-off-by: David Howells <dhowells@redhat.com>
---
kernel/Makefile | 35 +++++++++++++++++++++++++++++------
kernel/modsign_certificate.S | 3 +--
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/kernel/Makefile b/kernel/Makefile
index 1ce4755..c34e5f9 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -142,17 +142,40 @@ $(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE
$(call if_changed,bc)
ifeq ($(CONFIG_MODULE_SIG),y)
+###############################################################################
#
-# Pull the signing certificate and any extra certificates into the kernel
+# Roll all the X.509 certificates that we can find together and pull
+# them into the kernel.
#
+###############################################################################
+X509_CERTIFICATES-y := $(wildcard *.x509) $(wildcard $(srctree)/*.x509)
+X509_CERTIFICATES-$(CONFIG_MODULE_SIG) += signing_key.x509
+X509_CERTIFICATES := $(sort $(X509_CERTIFICATES-y))
+
+ifeq ($(X509_CERTIFICATES),)
+$(warning *** No X.509 certificates found ***)
+endif
+
+ifneq ($(wildcard $(obj)/.x509.list),)
+ifneq ($(shell cat $(obj)/.x509.list),$(X509_CERTIFICATES))
+$(info X.509 certificate list changed)
+$(shell rm $(obj)/.x509.list)
+endif
+endif
+
+kernel/modsign_certificate.o: $(obj)/x509_certificate_list
-quiet_cmd_touch = TOUCH $@
- cmd_touch = touch $@
+quiet_cmd_x509certs = CERTS $@
+ cmd_x509certs = cat $(X509_CERTIFICATES) /dev/null >$@
+targets += $(obj)/x509_certificate_list
+$(obj)/x509_certificate_list: $(X509_CERTIFICATES) $(obj)/.x509.list
+ $(call if_changed,x509certs)
-extra_certificates:
- $(call cmd,touch)
+targets += $(obj)/.x509.list
+$(obj)/.x509.list:
+ @echo $(X509_CERTIFICATES) >$@
-kernel/modsign_certificate.o: signing_key.x509 extra_certificates
+clean-files := x509_certificate_list .x509.list
###############################################################################
#
diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S
index 4a9a86d..6fe03c7 100644
--- a/kernel/modsign_certificate.S
+++ b/kernel/modsign_certificate.S
@@ -7,6 +7,5 @@
.section ".init.data","aw"
GLOBAL(modsign_certificate_list)
- .incbin "signing_key.x509"
- .incbin "extra_certificates"
+ .incbin "kernel/x509_certificate_list"
GLOBAL(modsign_certificate_list_end)
--
1.8.3.1
From 068606ba7df3206e5a09b544b4b89ed09cd30f44 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 17:13:15 +0100
Subject: [PATCH 12/18] KEYS: Have make canonicalise the paths of the X.509
certs better to deduplicate
Have make canonicalise the paths of the X.509 certificates before we sort them
as this allows $(sort) to better remove duplicates.
Signed-off-by: David Howells <dhowells@redhat.com>
---
kernel/Makefile | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/kernel/Makefile b/kernel/Makefile
index c34e5f9..2c24195 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -144,13 +144,19 @@ $(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE
ifeq ($(CONFIG_MODULE_SIG),y)
###############################################################################
#
-# Roll all the X.509 certificates that we can find together and pull
-# them into the kernel.
+# Roll all the X.509 certificates that we can find together and pull them into
+# the kernel.
+#
+# We look in the source root and the build root for all files whose name ends
+# in ".x509". Unfortunately, this will generate duplicate filenames, so we
+# have make canonicalise the pathnames and then sort them to discard the
+# duplicates.
#
###############################################################################
X509_CERTIFICATES-y := $(wildcard *.x509) $(wildcard $(srctree)/*.x509)
X509_CERTIFICATES-$(CONFIG_MODULE_SIG) += signing_key.x509
-X509_CERTIFICATES := $(sort $(X509_CERTIFICATES-y))
+X509_CERTIFICATES := $(sort $(foreach CERT,$(X509_CERTIFICATES-y), \
+ $(or $(realpath $(CERT)),$(CERT))))
ifeq ($(X509_CERTIFICATES),)
$(warning *** No X.509 certificates found ***)
--
1.8.3.1
From 9006cfbd669e9ba52d1a91db2ffd9482ad8a6090 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:07:30 +0100
Subject: [PATCH 13/18] KEYS: Separate the kernel signature checking keyring
from module signing
Separate the kernel signature checking keyring from module signing so that it
can be used by code other than the module-signing code.
Signed-off-by: David Howells <dhowells@redhat.com>
---
include/keys/system_keyring.h | 23 ++++++++++
init/Kconfig | 13 ++++++
kernel/Makefile | 15 ++++--
kernel/modsign_certificate.S | 11 -----
kernel/modsign_pubkey.c | 104 ------------------------------------------
kernel/module-internal.h | 2 -
kernel/module_signing.c | 3 +-
kernel/system_certificates.S | 11 +++++
kernel/system_keyring.c | 103 +++++++++++++++++++++++++++++++++++++++++
9 files changed, 162 insertions(+), 123 deletions(-)
create mode 100644 include/keys/system_keyring.h
delete mode 100644 kernel/modsign_certificate.S
delete mode 100644 kernel/modsign_pubkey.c
create mode 100644 kernel/system_certificates.S
create mode 100644 kernel/system_keyring.c
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
new file mode 100644
index 0000000..8dabc39
--- /dev/null
+++ b/include/keys/system_keyring.h
@@ -0,0 +1,23 @@
+/* System keyring containing trusted public keys.
+ *
+ * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _KEYS_SYSTEM_KEYRING_H
+#define _KEYS_SYSTEM_KEYRING_H
+
+#ifdef CONFIG_SYSTEM_TRUSTED_KEYRING
+
+#include <linux/key.h>
+
+extern struct key *system_trusted_keyring;
+
+#endif
+
+#endif /* _KEYS_SYSTEM_KEYRING_H */
diff --git a/init/Kconfig b/init/Kconfig
index 18bd9e3..cf14d07 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1668,6 +1668,18 @@ config BASE_SMALL
default 0 if BASE_FULL
default 1 if !BASE_FULL
+config SYSTEM_TRUSTED_KEYRING
+ bool "Provide system-wide ring of trusted keys"
+ depends on KEYS
+ help
+ Provide a system keyring to which trusted keys can be added. Keys in
+ the keyring are considered to be trusted. Keys may be added at will
+ by the kernel from compiled-in data and from hardware key stores, but
+ userspace may only add extra keys if those keys can be verified by
+ keys already in the keyring.
+
+ Keys in this keyring are used by module signature checking.
+
menuconfig MODULES
bool "Enable loadable module support"
option modules
@@ -1741,6 +1753,7 @@ config MODULE_SRCVERSION_ALL
config MODULE_SIG
bool "Module signature verification"
depends on MODULES
+ select SYSTEM_TRUSTED_KEYRING
select KEYS
select CRYPTO
select ASYMMETRIC_KEY_TYPE
diff --git a/kernel/Makefile b/kernel/Makefile
index 2c24195..6313698 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -54,8 +54,9 @@ obj-$(CONFIG_SMP) += spinlock.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
obj-$(CONFIG_UID16) += uid16.o
+obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
obj-$(CONFIG_MODULES) += module.o
-obj-$(CONFIG_MODULE_SIG) += module_signing.o modsign_pubkey.o modsign_certificate.o
+obj-$(CONFIG_MODULE_SIG) += module_signing.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
obj-$(CONFIG_KEXEC) += kexec.o
@@ -141,11 +142,11 @@ targets += timeconst.h
$(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE
$(call if_changed,bc)
-ifeq ($(CONFIG_MODULE_SIG),y)
###############################################################################
#
# Roll all the X.509 certificates that we can find together and pull them into
-# the kernel.
+# the kernel so that they get loaded into the system trusted keyring during
+# boot.
#
# We look in the source root and the build root for all files whose name ends
# in ".x509". Unfortunately, this will generate duplicate filenames, so we
@@ -153,6 +154,7 @@ ifeq ($(CONFIG_MODULE_SIG),y)
# duplicates.
#
###############################################################################
+ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
X509_CERTIFICATES-y := $(wildcard *.x509) $(wildcard $(srctree)/*.x509)
X509_CERTIFICATES-$(CONFIG_MODULE_SIG) += signing_key.x509
X509_CERTIFICATES := $(sort $(foreach CERT,$(X509_CERTIFICATES-y), \
@@ -169,10 +171,11 @@ $(shell rm $(obj)/.x509.list)
endif
endif
-kernel/modsign_certificate.o: $(obj)/x509_certificate_list
+kernel/system_certificates.o: $(obj)/x509_certificate_list
quiet_cmd_x509certs = CERTS $@
- cmd_x509certs = cat $(X509_CERTIFICATES) /dev/null >$@
+ cmd_x509certs = cat $(X509_CERTIFICATES) /dev/null >$@ $(foreach X509,$(X509_CERTIFICATES),; echo " - Including cert $(X509)")
+
targets += $(obj)/x509_certificate_list
$(obj)/x509_certificate_list: $(X509_CERTIFICATES) $(obj)/.x509.list
$(call if_changed,x509certs)
@@ -182,7 +185,9 @@ $(obj)/.x509.list:
@echo $(X509_CERTIFICATES) >$@
clean-files := x509_certificate_list .x509.list
+endif
+ifeq ($(CONFIG_MODULE_SIG),y)
###############################################################################
#
# If module signing is requested, say by allyesconfig, but a key has not been
diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S
deleted file mode 100644
index 6fe03c7..0000000
--- a/kernel/modsign_certificate.S
+++ /dev/null
@@ -1,11 +0,0 @@
-#include <linux/export.h>
-
-#define GLOBAL(name) \
- .globl VMLINUX_SYMBOL(name); \
- VMLINUX_SYMBOL(name):
-
- .section ".init.data","aw"
-
-GLOBAL(modsign_certificate_list)
- .incbin "kernel/x509_certificate_list"
-GLOBAL(modsign_certificate_list_end)
diff --git a/kernel/modsign_pubkey.c b/kernel/modsign_pubkey.c
deleted file mode 100644
index 7cbd450..0000000
--- a/kernel/modsign_pubkey.c
+++ /dev/null
@@ -1,104 +0,0 @@
-/* Public keys for module signature verification
- *
- * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/cred.h>
-#include <linux/err.h>
-#include <keys/asymmetric-type.h>
-#include "module-internal.h"
-
-struct key *modsign_keyring;
-
-extern __initconst const u8 modsign_certificate_list[];
-extern __initconst const u8 modsign_certificate_list_end[];
-
-/*
- * We need to make sure ccache doesn't cache the .o file as it doesn't notice
- * if modsign.pub changes.
- */
-static __initconst const char annoy_ccache[] = __TIME__ "foo";
-
-/*
- * Load the compiled-in keys
- */
-static __init int module_verify_init(void)
-{
- pr_notice("Initialise module verification\n");
-
- modsign_keyring = keyring_alloc(".module_sign",
- KUIDT_INIT(0), KGIDT_INIT(0),
- current_cred(),
- ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ),
- KEY_ALLOC_NOT_IN_QUOTA, NULL);
- if (IS_ERR(modsign_keyring))
- panic("Can't allocate module signing keyring\n");
-
- return 0;
-}
-
-/*
- * Must be initialised before we try and load the keys into the keyring.
- */
-device_initcall(module_verify_init);
-
-/*
- * Load the compiled-in keys
- */
-static __init int load_module_signing_keys(void)
-{
- key_ref_t key;
- const u8 *p, *end;
- size_t plen;
-
- pr_notice("Loading module verification certificates\n");
-
- end = modsign_certificate_list_end;
- p = modsign_certificate_list;
- while (p < end) {
- /* Each cert begins with an ASN.1 SEQUENCE tag and must be more
- * than 256 bytes in size.
- */
- if (end - p < 4)
- goto dodgy_cert;
- if (p[0] != 0x30 &&
- p[1] != 0x82)
- goto dodgy_cert;
- plen = (p[2] << 8) | p[3];
- plen += 4;
- if (plen > end - p)
- goto dodgy_cert;
-
- key = key_create_or_update(make_key_ref(modsign_keyring, 1),
- "asymmetric",
- NULL,
- p,
- plen,
- (KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW,
- KEY_ALLOC_NOT_IN_QUOTA);
- if (IS_ERR(key))
- pr_err("MODSIGN: Problem loading in-kernel X.509 certificate (%ld)\n",
- PTR_ERR(key));
- else
- pr_notice("MODSIGN: Loaded cert '%s'\n",
- key_ref_to_ptr(key)->description);
- p += plen;
- }
-
- return 0;
-
-dodgy_cert:
- pr_err("MODSIGN: Problem parsing in-kernel X.509 certificate list\n");
- return 0;
-}
-late_initcall(load_module_signing_keys);
diff --git a/kernel/module-internal.h b/kernel/module-internal.h
index 24f9247..915e123 100644
--- a/kernel/module-internal.h
+++ b/kernel/module-internal.h
@@ -9,6 +9,4 @@
* 2 of the Licence, or (at your option) any later version.
*/
-extern struct key *modsign_keyring;
-
extern int mod_verify_sig(const void *mod, unsigned long *_modlen);
diff --git a/kernel/module_signing.c b/kernel/module_signing.c
index ee47640..0b6b870 100644
--- a/kernel/module_signing.c
+++ b/kernel/module_signing.c
@@ -14,6 +14,7 @@
#include <crypto/public_key.h>
#include <crypto/hash.h>
#include <keys/asymmetric-type.h>
+#include <keys/system_keyring.h>
#include "module-internal.h"
/*
@@ -157,7 +158,7 @@ static struct key *request_asymmetric_key(const char *signer, size_t signer_len,
pr_debug("Look up: \"%s\"\n", id);
- key = keyring_search(make_key_ref(modsign_keyring, 1),
+ key = keyring_search(make_key_ref(system_trusted_keyring, 1),
&key_type_asymmetric, id);
if (IS_ERR(key))
pr_warn("Request for unknown module key '%s' err %ld\n",
diff --git a/kernel/system_certificates.S b/kernel/system_certificates.S
new file mode 100644
index 0000000..5cffe86
--- /dev/null
+++ b/kernel/system_certificates.S
@@ -0,0 +1,11 @@
+#include <linux/export.h>
+
+#define GLOBAL(name) \
+ .globl VMLINUX_SYMBOL(name); \
+ VMLINUX_SYMBOL(name):
+
+ .section ".init.data","aw"
+
+GLOBAL(system_certificate_list)
+ .incbin "kernel/x509_certificate_list"
+GLOBAL(system_certificate_list_end)
diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c
new file mode 100644
index 0000000..51c3514
--- /dev/null
+++ b/kernel/system_keyring.c
@@ -0,0 +1,103 @@
+/* System trusted keyring for trusted public keys
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/err.h>
+#include <keys/asymmetric-type.h>
+#include <keys/system_keyring.h>
+#include "module-internal.h"
+
+struct key *system_trusted_keyring;
+EXPORT_SYMBOL_GPL(system_trusted_keyring);
+
+extern __initconst const u8 system_certificate_list[];
+extern __initconst const u8 system_certificate_list_end[];
+
+/*
+ * Load the compiled-in keys
+ */
+static __init int system_trusted_keyring_init(void)
+{
+ pr_notice("Initialise system trusted keyring\n");
+
+ system_trusted_keyring =
+ keyring_alloc(".system_keyring",
+ KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
+ ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ KEY_USR_VIEW | KEY_USR_READ),
+ KEY_ALLOC_NOT_IN_QUOTA, NULL);
+ if (IS_ERR(system_trusted_keyring))
+ panic("Can't allocate system trusted keyring\n");
+
+ return 0;
+}
+
+/*
+ * Must be initialised before we try and load the keys into the keyring.
+ */
+device_initcall(system_trusted_keyring_init);
+
+/*
+ * Load the compiled-in list of X.509 certificates.
+ */
+static __init int load_system_certificate_list(void)
+{
+ key_ref_t key;
+ const u8 *p, *end;
+ size_t plen;
+
+ pr_notice("Loading compiled-in X.509 certificates\n");
+
+ end = system_certificate_list_end;
+ p = system_certificate_list;
+ while (p < end) {
+ /* Each cert begins with an ASN.1 SEQUENCE tag and must be more
+ * than 256 bytes in size.
+ */
+ if (end - p < 4)
+ goto dodgy_cert;
+ if (p[0] != 0x30 &&
+ p[1] != 0x82)
+ goto dodgy_cert;
+ plen = (p[2] << 8) | p[3];
+ plen += 4;
+ if (plen > end - p)
+ goto dodgy_cert;
+
+ key = key_create_or_update(make_key_ref(system_trusted_keyring, 1),
+ "asymmetric",
+ NULL,
+ p,
+ plen,
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ KEY_USR_VIEW,
+ KEY_ALLOC_NOT_IN_QUOTA);
+ if (IS_ERR(key)) {
+ pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
+ PTR_ERR(key));
+ } else {
+ pr_notice("Loaded X.509 cert '%s'\n",
+ key_ref_to_ptr(key)->description);
+ key_ref_put(key);
+ }
+ p += plen;
+ }
+
+ return 0;
+
+dodgy_cert:
+ pr_err("Problem parsing in-kernel X.509 certificate list\n");
+ return 0;
+}
+late_initcall(load_system_certificate_list);
--
1.8.3.1
From c0522b3236c27359bd61fee0f0b74be9f8e2ad60 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Fri, 30 Aug 2013 16:07:37 +0100
Subject: [PATCH 14/18] KEYS: Add a 'trusted' flag and a 'trusted only' flag
Add KEY_FLAG_TRUSTED to indicate that a key either comes from a trusted source
or had a cryptographic signature chain that led back to a trusted key the
kernel already possessed.
Add KEY_FLAGS_TRUSTED_ONLY to indicate that a keyring will only accept links to
keys marked with KEY_FLAGS_TRUSTED.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
include/linux/key-type.h | 1 +
include/linux/key.h | 3 +++
kernel/system_keyring.c | 4 +++-
security/keys/key.c | 8 ++++++++
security/keys/keyring.c | 4 ++++
5 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/include/linux/key-type.h b/include/linux/key-type.h
index f58737b..a74c3a8 100644
--- a/include/linux/key-type.h
+++ b/include/linux/key-type.h
@@ -45,6 +45,7 @@ struct key_preparsed_payload {
const void *data; /* Raw data */
size_t datalen; /* Raw datalen */
size_t quotalen; /* Quota length for proposed payload */
+ bool trusted; /* True if key is trusted */
};
typedef int (*request_key_actor_t)(struct key_construction *key,
diff --git a/include/linux/key.h b/include/linux/key.h
index 010dbb6..80d6774 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -168,6 +168,8 @@ struct key {
#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */
#define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */
#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */
+#define KEY_FLAG_TRUSTED 8 /* set if key is trusted */
+#define KEY_FLAG_TRUSTED_ONLY 9 /* set if keyring only accepts links to trusted keys */
/* the key type and key description string
* - the desc is used to match a key against search criteria
@@ -218,6 +220,7 @@ extern struct key *key_alloc(struct key_type *type,
#define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */
#define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */
#define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */
+#define KEY_ALLOC_TRUSTED 0x0004 /* Key should be flagged as trusted */
extern void key_revoke(struct key *key);
extern void key_invalidate(struct key *key);
diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c
index 51c3514..5296721 100644
--- a/kernel/system_keyring.c
+++ b/kernel/system_keyring.c
@@ -40,6 +40,7 @@ static __init int system_trusted_keyring_init(void)
if (IS_ERR(system_trusted_keyring))
panic("Can't allocate system trusted keyring\n");
+ set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags);
return 0;
}
@@ -82,7 +83,8 @@ static __init int load_system_certificate_list(void)
plen,
(KEY_POS_ALL & ~KEY_POS_SETATTR) |
KEY_USR_VIEW,
- KEY_ALLOC_NOT_IN_QUOTA);
+ KEY_ALLOC_NOT_IN_QUOTA |
+ KEY_ALLOC_TRUSTED);
if (IS_ERR(key)) {
pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
PTR_ERR(key));
diff --git a/security/keys/key.c b/security/keys/key.c
index a819b5c..d331ea9 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -300,6 +300,8 @@ struct key *key_alloc(struct key_type *type, const char *desc,
if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
key->flags |= 1 << KEY_FLAG_IN_QUOTA;
+ if (flags & KEY_ALLOC_TRUSTED)
+ key->flags |= 1 << KEY_FLAG_TRUSTED;
memset(&key->type_data, 0, sizeof(key->type_data));
@@ -813,6 +815,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
prep.data = payload;
prep.datalen = plen;
prep.quotalen = index_key.type->def_datalen;
+ prep.trusted = flags & KEY_ALLOC_TRUSTED;
if (index_key.type->preparse) {
ret = index_key.type->preparse(&prep);
if (ret < 0) {
@@ -827,6 +830,11 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
}
index_key.desc_len = strlen(index_key.description);
+ key_ref = ERR_PTR(-EPERM);
+ if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags))
+ goto error_free_prep;
+ flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0;
+
ret = __key_link_begin(keyring, &index_key, &edit);
if (ret < 0) {
key_ref = ERR_PTR(ret);
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index f7cdea2..9b6f6e0 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1183,6 +1183,10 @@ int key_link(struct key *keyring, struct key *key)
key_check(keyring);
key_check(key);
+ if (test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags) &&
+ !test_bit(KEY_FLAG_TRUSTED, &key->flags))
+ return -EPERM;
+
ret = __key_link_begin(keyring, &key->index_key, &edit);
if (ret == 0) {
kdebug("begun {%d,%d}", keyring->serial, atomic_read(&keyring->usage));
--
1.8.3.1
From e8e9a6af1d2de6aca01751ccaf0475ed46f9bdb2 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Wed, 4 Sep 2013 19:28:03 +0100
Subject: [PATCH 15/18] KEYS: Set the asymmetric-key type default search method
The keyring expansion patches introduces a new search method by which
key_search() attempts to walk directly to the key that has exactly the same
description as the requested one.
However, this causes inexact matching of asymmetric keys to fail. The
solution to this is to select iterative rather than direct search as the
default search type for asymmetric keys.
As an example, the kernel might have a key like this:
Magrathea: Glacier signing key: 6a2a0f82bad7e396665f465e4e3e1f9bd24b1226
and:
keyctl search <keyring-ID> asymmetric id:d24b1226
should find the key, despite that not being its exact description.
Signed-off-by: David Howells <dhowells@redhat.com>
---
crypto/asymmetric_keys/asymmetric_type.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index cf80765..b77eb53 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -209,6 +209,7 @@ struct key_type key_type_asymmetric = {
.match = asymmetric_key_match,
.destroy = asymmetric_key_destroy,
.describe = asymmetric_key_describe,
+ .def_lookup_type = KEYRING_SEARCH_LOOKUP_ITERATE,
};
EXPORT_SYMBOL_GPL(key_type_asymmetric);
--
1.8.3.1
From dfb7781ebba28004f95f7af4e039d8b44697c87c Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
Date: Tue, 20 Aug 2013 14:36:26 -0400
Subject: [PATCH 16/18] KEYS: Make the system 'trusted' keyring viewable by
userspace
Give the root user the ability to read the system keyring and put read
permission on the trusted keys added during boot. The latter is actually more
theoretical than real for the moment as asymmetric keys do not currently
provide a read operation.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---
kernel/system_keyring.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c
index 5296721..564dd93 100644
--- a/kernel/system_keyring.c
+++ b/kernel/system_keyring.c
@@ -35,7 +35,7 @@ static __init int system_trusted_keyring_init(void)
keyring_alloc(".system_keyring",
KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
((KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW | KEY_USR_READ),
+ KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH),
KEY_ALLOC_NOT_IN_QUOTA, NULL);
if (IS_ERR(system_trusted_keyring))
panic("Can't allocate system trusted keyring\n");
@@ -81,8 +81,8 @@ static __init int load_system_certificate_list(void)
NULL,
p,
plen,
- (KEY_POS_ALL & ~KEY_POS_SETATTR) |
- KEY_USR_VIEW,
+ ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ KEY_USR_VIEW | KEY_USR_READ),
KEY_ALLOC_NOT_IN_QUOTA |
KEY_ALLOC_TRUSTED);
if (IS_ERR(key)) {
--
1.8.3.1
From 052744b12209e66ede2a04ec31b9bb7ff40bbc9a Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
Date: Tue, 20 Aug 2013 14:36:27 -0400
Subject: [PATCH 17/18] KEYS: verify a certificate is signed by a 'trusted' key
Only public keys, with certificates signed by an existing
'trusted' key on the system trusted keyring, should be added
to a trusted keyring. This patch adds support for verifying
a certificate's signature.
This is derived from David Howells pkcs7_request_asymmetric_key() patch.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---
crypto/asymmetric_keys/x509_public_key.c | 81 +++++++++++++++++++++++++++++++-
1 file changed, 80 insertions(+), 1 deletion(-)
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index c1540e8..8761264 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -18,12 +18,60 @@
#include <linux/asn1_decoder.h>
#include <keys/asymmetric-subtype.h>
#include <keys/asymmetric-parser.h>
+#include <keys/system_keyring.h>
#include <crypto/hash.h>
#include "asymmetric_keys.h"
#include "public_key.h"
#include "x509_parser.h"
/*
+ * Find a key in the given keyring by issuer and authority.
+ */
+static struct key *x509_request_asymmetric_key(
+ struct key *keyring,
+ const char *signer, size_t signer_len,
+ const char *authority, size_t auth_len)
+{
+ key_ref_t key;
+ char *id;
+
+ /* Construct an identifier. */
+ id = kmalloc(signer_len + 2 + auth_len + 1, GFP_KERNEL);
+ if (!id)
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(id, signer, signer_len);
+ id[signer_len + 0] = ':';
+ id[signer_len + 1] = ' ';
+ memcpy(id + signer_len + 2, authority, auth_len);
+ id[signer_len + 2 + auth_len] = 0;
+
+ pr_debug("Look up: \"%s\"\n", id);
+
+ key = keyring_search(make_key_ref(keyring, 1),
+ &key_type_asymmetric, id);
+ if (IS_ERR(key))
+ pr_debug("Request for module key '%s' err %ld\n",
+ id, PTR_ERR(key));
+ kfree(id);
+
+ if (IS_ERR(key)) {
+ switch (PTR_ERR(key)) {
+ /* Hide some search errors */
+ case -EACCES:
+ case -ENOTDIR:
+ case -EAGAIN:
+ return ERR_PTR(-ENOKEY);
+ default:
+ return ERR_CAST(key);
+ }
+ }
+
+ pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key_ref_to_ptr(key)));
+ return key_ref_to_ptr(key);
+}
+
+/*
* Set up the signature parameters in an X.509 certificate. This involves
* digesting the signed data and extracting the signature.
*/
@@ -103,6 +151,33 @@ int x509_check_signature(const struct public_key *pub,
EXPORT_SYMBOL_GPL(x509_check_signature);
/*
+ * Check the new certificate against the ones in the trust keyring. If one of
+ * those is the signing key and validates the new certificate, then mark the
+ * new certificate as being trusted.
+ *
+ * Return 0 if the new certificate was successfully validated, 1 if we couldn't
+ * find a matching parent certificate in the trusted list and an error if there
+ * is a matching certificate but the signature check fails.
+ */
+static int x509_validate_trust(struct x509_certificate *cert,
+ struct key *trust_keyring)
+{
+ const struct public_key *pk;
+ struct key *key;
+ int ret = 1;
+
+ key = x509_request_asymmetric_key(trust_keyring,
+ cert->issuer, strlen(cert->issuer),
+ cert->authority,
+ strlen(cert->authority));
+ if (!IS_ERR(key)) {
+ pk = key->payload.data;
+ ret = x509_check_signature(pk, cert);
+ }
+ return ret;
+}
+
+/*
* Attempt to parse a data blob for a key as an X509 certificate.
*/
static int x509_key_preparse(struct key_preparsed_payload *prep)
@@ -155,9 +230,13 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
/* Check the signature on the key if it appears to be self-signed */
if (!cert->authority ||
strcmp(cert->fingerprint, cert->authority) == 0) {
- ret = x509_check_signature(cert->pub, cert);
+ ret = x509_check_signature(cert->pub, cert); /* self-signed */
if (ret < 0)
goto error_free_cert;
+ } else {
+ ret = x509_validate_trust(cert, system_trusted_keyring);
+ if (!ret)
+ prep->trusted = 1;
}
/* Propose a description */
--
1.8.3.1
From 8b39d9a6d9f805f6a2e837bf8b9595f701ea4a1c Mon Sep 17 00:00:00 2001
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
Date: Wed, 4 Sep 2013 13:26:22 +0100
Subject: [PATCH 18/18] KEYS: initialize root uid and session keyrings early
In order to create the integrity keyrings (eg. _evm, _ima), root's
uid and session keyrings need to be initialized early.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---
security/keys/process_keys.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 68548ea..0cf8a13 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -857,3 +857,13 @@ void key_change_session_keyring(struct callback_head *twork)
commit_creds(new);
}
+
+/*
+ * Make sure that root's user and user-session keyrings exist.
+ */
+static int __init init_root_keyring(void)
+{
+ return install_user_keyrings();
+}
+
+late_initcall(init_root_keyring);
--
1.8.3.1