KEYS: Generalise system_verify_data() to provide access to internal content
Generalise system_verify_data() to provide access to internal content
through a callback. This allows all the PKCS#7 stuff to be hidden inside
this function and removed from the PE file parser and the PKCS#7 test key.
If external content is not required, NULL should be passed as data to the
function. If the callback is not required, that can be set to NULL.
The function is now called verify_pkcs7_signature() to contrast with
verify_pefile_signature() and the definitions of both have been moved into
linux/verification.h along with the key_being_used_for enum.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
index 91a7e04..f7d2ef9 100644
--- a/crypto/asymmetric_keys/Kconfig
+++ b/crypto/asymmetric_keys/Kconfig
@@ -40,8 +40,7 @@
config PKCS7_TEST_KEY
tristate "PKCS#7 testing key type"
- depends on PKCS7_MESSAGE_PARSER
- select SYSTEM_TRUSTED_KEYRING
+ depends on SYSTEM_DATA_VERIFICATION
help
This option provides a type of key that can be loaded up from a
PKCS#7 message - provided the message is signed by a trusted key. If
@@ -54,6 +53,7 @@
config SIGNED_PE_FILE_VERIFICATION
bool "Support for PE file signature verification"
depends on PKCS7_MESSAGE_PARSER=y
+ depends on SYSTEM_DATA_VERIFICATION
select ASN1
select OID_REGISTRY
help
diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c
index 3242cbf..6a76d5c 100644
--- a/crypto/asymmetric_keys/mscode_parser.c
+++ b/crypto/asymmetric_keys/mscode_parser.c
@@ -21,19 +21,13 @@
/*
* Parse a Microsoft Individual Code Signing blob
*/
-int mscode_parse(struct pefile_context *ctx)
+int mscode_parse(void *_ctx, const void *content_data, size_t data_len,
+ size_t asn1hdrlen)
{
- const void *content_data;
- size_t data_len;
- int ret;
+ struct pefile_context *ctx = _ctx;
- ret = pkcs7_get_content_data(ctx->pkcs7, &content_data, &data_len, 1);
-
- if (ret) {
- pr_debug("PKCS#7 message does not contain data\n");
- return ret;
- }
-
+ content_data -= asn1hdrlen;
+ data_len += asn1hdrlen;
pr_devel("Data: %zu [%*ph]\n", data_len, (unsigned)(data_len),
content_data);
@@ -129,7 +123,6 @@
{
struct pefile_context *ctx = context;
- ctx->digest = value;
- ctx->digest_len = vlen;
- return 0;
+ ctx->digest = kmemdup(value, vlen, GFP_KERNEL);
+ return ctx->digest ? 0 : -ENOMEM;
}
diff --git a/crypto/asymmetric_keys/pkcs7_key_type.c b/crypto/asymmetric_keys/pkcs7_key_type.c
index e2d0edb..ab9bf53 100644
--- a/crypto/asymmetric_keys/pkcs7_key_type.c
+++ b/crypto/asymmetric_keys/pkcs7_key_type.c
@@ -13,12 +13,9 @@
#include <linux/key.h>
#include <linux/err.h>
#include <linux/module.h>
+#include <linux/verification.h>
#include <linux/key-type.h>
-#include <keys/asymmetric-type.h>
-#include <crypto/pkcs7.h>
#include <keys/user-type.h>
-#include <keys/system_keyring.h>
-#include "pkcs7_parser.h"
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PKCS#7 testing key type");
@@ -29,57 +26,44 @@
"Usage to specify when verifying the PKCS#7 message");
/*
+ * Retrieve the PKCS#7 message content.
+ */
+static int pkcs7_view_content(void *ctx, const void *data, size_t len,
+ size_t asn1hdrlen)
+{
+ struct key_preparsed_payload *prep = ctx;
+ const void *saved_prep_data;
+ size_t saved_prep_datalen;
+ int ret;
+
+ saved_prep_data = prep->data;
+ saved_prep_datalen = prep->datalen;
+ prep->data = data;
+ prep->datalen = len;
+
+ ret = user_preparse(prep);
+
+ prep->data = saved_prep_data;
+ prep->datalen = saved_prep_datalen;
+ return ret;
+}
+
+/*
* Preparse a PKCS#7 wrapped and validated data blob.
*/
static int pkcs7_preparse(struct key_preparsed_payload *prep)
{
enum key_being_used_for usage = pkcs7_usage;
- struct pkcs7_message *pkcs7;
- const void *data, *saved_prep_data;
- size_t datalen, saved_prep_datalen;
- bool trusted;
- int ret;
-
- kenter("");
if (usage >= NR__KEY_BEING_USED_FOR) {
pr_err("Invalid usage type %d\n", usage);
return -EINVAL;
}
- saved_prep_data = prep->data;
- saved_prep_datalen = prep->datalen;
- pkcs7 = pkcs7_parse_message(saved_prep_data, saved_prep_datalen);
- if (IS_ERR(pkcs7)) {
- ret = PTR_ERR(pkcs7);
- goto error;
- }
-
- ret = pkcs7_verify(pkcs7, usage);
- if (ret < 0)
- goto error_free;
-
- ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
- if (ret < 0)
- goto error_free;
- if (!trusted)
- pr_warn("PKCS#7 message doesn't chain back to a trusted key\n");
-
- ret = pkcs7_get_content_data(pkcs7, &data, &datalen, false);
- if (ret < 0)
- goto error_free;
-
- prep->data = data;
- prep->datalen = datalen;
- ret = user_preparse(prep);
- prep->data = saved_prep_data;
- prep->datalen = saved_prep_datalen;
-
-error_free:
- pkcs7_free_message(pkcs7);
-error:
- kleave(" = %d", ret);
- return ret;
+ return verify_pkcs7_signature(NULL, 0,
+ prep->data, prep->datalen,
+ NULL, -ENOKEY, usage,
+ pkcs7_view_content, prep);
}
/*
diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
index 8357016..af4cd86 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.c
+++ b/crypto/asymmetric_keys/pkcs7_parser.c
@@ -168,24 +168,25 @@
* @pkcs7: The preparsed PKCS#7 message to access
* @_data: Place to return a pointer to the data
* @_data_len: Place to return the data length
- * @want_wrapper: True if the ASN.1 object header should be included in the data
+ * @_headerlen: Size of ASN.1 header not included in _data
*
- * Get access to the data content of the PKCS#7 message, including, optionally,
- * the header of the ASN.1 object that contains it. Returns -ENODATA if the
- * data object was missing from the message.
+ * Get access to the data content of the PKCS#7 message. The size of the
+ * header of the ASN.1 object that contains it is also provided and can be used
+ * to adjust *_data and *_data_len to get the entire object.
+ *
+ * Returns -ENODATA if the data object was missing from the message.
*/
int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
const void **_data, size_t *_data_len,
- bool want_wrapper)
+ size_t *_headerlen)
{
- size_t wrapper;
-
if (!pkcs7->data)
return -ENODATA;
- wrapper = want_wrapper ? pkcs7->data_hdrlen : 0;
- *_data = pkcs7->data - wrapper;
- *_data_len = pkcs7->data_len + wrapper;
+ *_data = pkcs7->data;
+ *_data_len = pkcs7->data_len;
+ if (_headerlen)
+ *_headerlen = pkcs7->data_hdrlen;
return 0;
}
EXPORT_SYMBOL_GPL(pkcs7_get_content_data);
diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c
index 7e8c233..2653510 100644
--- a/crypto/asymmetric_keys/verify_pefile.c
+++ b/crypto/asymmetric_keys/verify_pefile.c
@@ -16,7 +16,7 @@
#include <linux/err.h>
#include <linux/pe.h>
#include <linux/asn1.h>
-#include <crypto/pkcs7.h>
+#include <linux/verification.h>
#include <crypto/hash.h>
#include "verify_pefile.h"
@@ -392,9 +392,8 @@
* verify_pefile_signature - Verify the signature on a PE binary image
* @pebuf: Buffer containing the PE binary image
* @pelen: Length of the binary image
- * @trust_keyring: Signing certificates to use as starting points
+ * @trust_keys: Signing certificate(s) to use as starting points
* @usage: The use to which the key is being put.
- * @_trusted: Set to true if trustworth, false otherwise
*
* Validate that the certificate chain inside the PKCS#7 message inside the PE
* binary image intersects keys we already know and trust.
@@ -418,14 +417,10 @@
* May also return -ENOMEM.
*/
int verify_pefile_signature(const void *pebuf, unsigned pelen,
- struct key *trusted_keyring,
- enum key_being_used_for usage,
- bool *_trusted)
+ struct key *trusted_keys,
+ enum key_being_used_for usage)
{
- struct pkcs7_message *pkcs7;
struct pefile_context ctx;
- const void *data;
- size_t datalen;
int ret;
kenter("");
@@ -439,19 +434,10 @@
if (ret < 0)
return ret;
- pkcs7 = pkcs7_parse_message(pebuf + ctx.sig_offset, ctx.sig_len);
- if (IS_ERR(pkcs7))
- return PTR_ERR(pkcs7);
- ctx.pkcs7 = pkcs7;
-
- ret = pkcs7_get_content_data(ctx.pkcs7, &data, &datalen, false);
- if (ret < 0 || datalen == 0) {
- pr_devel("PKCS#7 message does not contain data\n");
- ret = -EBADMSG;
- goto error;
- }
-
- ret = mscode_parse(&ctx);
+ ret = verify_pkcs7_signature(NULL, 0,
+ pebuf + ctx.sig_offset, ctx.sig_len,
+ trusted_keys, -EKEYREJECTED, usage,
+ mscode_parse, &ctx);
if (ret < 0)
goto error;
@@ -462,16 +448,8 @@
* contents.
*/
ret = pefile_digest_pe(pebuf, pelen, &ctx);
- if (ret < 0)
- goto error;
-
- ret = pkcs7_verify(pkcs7, usage);
- if (ret < 0)
- goto error;
-
- ret = pkcs7_validate_trust(pkcs7, trusted_keyring, _trusted);
error:
- pkcs7_free_message(ctx.pkcs7);
+ kfree(ctx.digest);
return ret;
}
diff --git a/crypto/asymmetric_keys/verify_pefile.h b/crypto/asymmetric_keys/verify_pefile.h
index a133eb8..cd4d209 100644
--- a/crypto/asymmetric_keys/verify_pefile.h
+++ b/crypto/asymmetric_keys/verify_pefile.h
@@ -9,7 +9,6 @@
* 2 of the Licence, or (at your option) any later version.
*/
-#include <linux/verify_pefile.h>
#include <crypto/pkcs7.h>
#include <crypto/hash_info.h>
@@ -23,7 +22,6 @@
unsigned sig_offset;
unsigned sig_len;
const struct section_header *secs;
- struct pkcs7_message *pkcs7;
/* PKCS#7 MS Individual Code Signing content */
const void *digest; /* Digest */
@@ -39,4 +37,5 @@
/*
* mscode_parser.c
*/
-extern int mscode_parse(struct pefile_context *ctx);
+extern int mscode_parse(void *_ctx, const void *content_data, size_t data_len,
+ size_t asn1hdrlen);
