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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-21 17:18:12 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-21 17:18:12 +0100
commit33673dcb372b5d8179c22127ca71deb5f3dc7016 (patch)
treed182e9dc6aa127375a92b5eb619d6cd2ddc23ce7 /security/integrity/digsig_asymmetric.c
parentKEYS: Revert one application of "Fix unreachable code" patch (diff)
parenttpm/ibmvtpm: build only when IBM pseries is configured (diff)
downloadlinux-33673dcb372b5d8179c22127ca71deb5f3dc7016.tar.xz
linux-33673dcb372b5d8179c22127ca71deb5f3dc7016.zip
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris: "This is basically a maintenance update for the TPM driver and EVM/IMA" Fix up conflicts in lib/digsig.c and security/integrity/ima/ima_main.c * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (45 commits) tpm/ibmvtpm: build only when IBM pseries is configured ima: digital signature verification using asymmetric keys ima: rename hash calculation functions ima: use new crypto_shash API instead of old crypto_hash ima: add policy support for file system uuid evm: add file system uuid to EVM hmac tpm_tis: check pnp_acpi_device return code char/tpm/tpm_i2c_stm_st33: drop temporary variable for return value char/tpm/tpm_i2c_stm_st33: remove dead assignment in tpm_st33_i2c_probe char/tpm/tpm_i2c_stm_st33: Remove __devexit attribute char/tpm/tpm_i2c_stm_st33: Don't use memcpy for one byte assignment tpm_i2c_stm_st33: removed unused variables/code TPM: Wait for TPM_ACCESS tpmRegValidSts to go high at startup tpm: Fix cancellation of TPM commands (interrupt mode) tpm: Fix cancellation of TPM commands (polling mode) tpm: Store TPM vendor ID TPM: Work around buggy TPMs that block during continue self test tpm_i2c_stm_st33: fix oops when i2c client is unavailable char/tpm: Use struct dev_pm_ops for power management TPM: STMicroelectronics ST33 I2C BUILD STUFF ...
Diffstat (limited to 'security/integrity/digsig_asymmetric.c')
-rw-r--r--security/integrity/digsig_asymmetric.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
new file mode 100644
index 000000000000..b4754667659d
--- /dev/null
+++ b/security/integrity/digsig_asymmetric.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2013 Intel Corporation
+ *
+ * Author:
+ * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/key-type.h>
+#include <crypto/public_key.h>
+#include <keys/asymmetric-type.h>
+
+#include "integrity.h"
+
+/*
+ * signature format v2 - for using with asymmetric keys
+ */
+struct signature_v2_hdr {
+ uint8_t version; /* signature format version */
+ uint8_t hash_algo; /* Digest algorithm [enum pkey_hash_algo] */
+ uint32_t keyid; /* IMA key identifier - not X509/PGP specific*/
+ uint16_t sig_size; /* signature size */
+ uint8_t sig[0]; /* signature payload */
+} __packed;
+
+/*
+ * Request an asymmetric key.
+ */
+static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
+{
+ struct key *key;
+ char name[12];
+
+ sprintf(name, "id:%x", keyid);
+
+ pr_debug("key search: \"%s\"\n", name);
+
+ if (keyring) {
+ /* search in specific keyring */
+ key_ref_t kref;
+ kref = keyring_search(make_key_ref(keyring, 1),
+ &key_type_asymmetric, name);
+ if (IS_ERR(kref))
+ key = ERR_CAST(kref);
+ else
+ key = key_ref_to_ptr(kref);
+ } else {
+ key = request_key(&key_type_asymmetric, name, NULL);
+ }
+
+ if (IS_ERR(key)) {
+ pr_warn("Request for unknown key '%s' err %ld\n",
+ name, PTR_ERR(key));
+ switch (PTR_ERR(key)) {
+ /* Hide some search errors */
+ case -EACCES:
+ case -ENOTDIR:
+ case -EAGAIN:
+ return ERR_PTR(-ENOKEY);
+ default:
+ return key;
+ }
+ }
+
+ pr_debug("%s() = 0 [%x]\n", __func__, key_serial(key));
+
+ return key;
+}
+
+int asymmetric_verify(struct key *keyring, const char *sig,
+ int siglen, const char *data, int datalen)
+{
+ struct public_key_signature pks;
+ struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
+ struct key *key;
+ int ret = -ENOMEM;
+
+ if (siglen <= sizeof(*hdr))
+ return -EBADMSG;
+
+ siglen -= sizeof(*hdr);
+
+ if (siglen != __be16_to_cpu(hdr->sig_size))
+ return -EBADMSG;
+
+ if (hdr->hash_algo >= PKEY_HASH__LAST)
+ return -ENOPKG;
+
+ key = request_asymmetric_key(keyring, __be32_to_cpu(hdr->keyid));
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+
+ memset(&pks, 0, sizeof(pks));
+
+ pks.pkey_hash_algo = hdr->hash_algo;
+ pks.digest = (u8 *)data;
+ pks.digest_size = datalen;
+ pks.nr_mpi = 1;
+ pks.rsa.s = mpi_read_raw_data(hdr->sig, siglen);
+
+ if (pks.rsa.s)
+ ret = verify_signature(key, &pks);
+
+ mpi_free(pks.rsa.s);
+ key_put(key);
+ pr_debug("%s() = %d\n", __func__, ret);
+ return ret;
+}