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authorDavid Howells <dhowells@redhat.com>2016-04-06 16:14:24 +0100
committerDavid Howells <dhowells@redhat.com>2016-04-06 16:14:24 +0100
commite68503bd6836ba765dc8e0ee77ea675fedc07e41 (patch)
tree31ebec81d2f52adc89796dd063468235bfd1cc0e /certs
parentad3043fda39db0361d9601685356db4512e914be (diff)
downloadlinux-stericsson-e68503bd6836ba765dc8e0ee77ea675fedc07e41.tar.gz
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>
Diffstat (limited to 'certs')
-rw-r--r--certs/system_keyring.c45
1 files changed, 35 insertions, 10 deletions
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index f4180326c2e1..a83bffedc0aa 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -108,16 +108,25 @@ late_initcall(load_system_certificate_list);
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
/**
- * Verify a PKCS#7-based signature on system data.
- * @data: The data to be verified.
+ * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data.
+ * @data: The data to be verified (NULL if expecting internal data).
* @len: Size of @data.
* @raw_pkcs7: The PKCS#7 message that is the signature.
* @pkcs7_len: The size of @raw_pkcs7.
+ * @trusted_keys: Trusted keys to use (NULL for system_trusted_keyring).
* @usage: The use to which the key is being put.
+ * @view_content: Callback to gain access to content.
+ * @ctx: Context for callback.
*/
-int system_verify_data(const void *data, unsigned long len,
- const void *raw_pkcs7, size_t pkcs7_len,
- enum key_being_used_for usage)
+int verify_pkcs7_signature(const void *data, size_t len,
+ const void *raw_pkcs7, size_t pkcs7_len,
+ struct key *trusted_keys,
+ int untrusted_error,
+ enum key_being_used_for usage,
+ int (*view_content)(void *ctx,
+ const void *data, size_t len,
+ size_t asn1hdrlen),
+ void *ctx)
{
struct pkcs7_message *pkcs7;
bool trusted;
@@ -128,7 +137,7 @@ int system_verify_data(const void *data, unsigned long len,
return PTR_ERR(pkcs7);
/* The data should be detached - so we need to supply it. */
- if (pkcs7_supply_detached_data(pkcs7, data, len) < 0) {
+ if (data && pkcs7_supply_detached_data(pkcs7, data, len) < 0) {
pr_err("PKCS#7 signature with non-detached data\n");
ret = -EBADMSG;
goto error;
@@ -138,13 +147,29 @@ int system_verify_data(const void *data, unsigned long len,
if (ret < 0)
goto error;
- ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
+ if (!trusted_keys)
+ trusted_keys = system_trusted_keyring;
+ ret = pkcs7_validate_trust(pkcs7, trusted_keys, &trusted);
if (ret < 0)
goto error;
- if (!trusted) {
+ if (!trusted && untrusted_error) {
pr_err("PKCS#7 signature not signed with a trusted key\n");
- ret = -ENOKEY;
+ ret = untrusted_error;
+ goto error;
+ }
+
+ if (view_content) {
+ size_t asn1hdrlen;
+
+ ret = pkcs7_get_content_data(pkcs7, &data, &len, &asn1hdrlen);
+ if (ret < 0) {
+ if (ret == -ENODATA)
+ pr_devel("PKCS#7 message does not contain data\n");
+ goto error;
+ }
+
+ ret = view_content(ctx, data, len, asn1hdrlen);
}
error:
@@ -152,6 +177,6 @@ error:
pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
}
-EXPORT_SYMBOL_GPL(system_verify_data);
+EXPORT_SYMBOL_GPL(verify_pkcs7_signature);
#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */