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Subject[PATCH 17/22] KEYS: asym_tpm: Add loadkey2 and flushspecific
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From: Denis Kenzior <denkenz@gmail.com>

This commit adds TPM_LoadKey2 and TPM_FlushSpecific operations.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
---

crypto/asymmetric_keys/asym_tpm.c | 94 +++++++++++++++++++++++++++++++++++++
1 file changed, 94 insertions(+)

diff --git a/crypto/asymmetric_keys/asym_tpm.c b/crypto/asymmetric_keys/asym_tpm.c
index 8edca3c4c193..6a2d33014ecc 100644
--- a/crypto/asymmetric_keys/asym_tpm.c
+++ b/crypto/asymmetric_keys/asym_tpm.c
@@ -7,11 +7,105 @@
#include <linux/seq_file.h>
#include <linux/scatterlist.h>
#include <linux/tpm.h>
+#include <linux/tpm_command.h>
#include <crypto/akcipher.h>
+#include <crypto/hash.h>
+#include <crypto/sha.h>
#include <asm/unaligned.h>
#include <keys/asymmetric-subtype.h>
+#include <keys/trusted.h>
#include <crypto/asym_tpm_subtype.h>

+#define TPM_ORD_FLUSHSPECIFIC 186
+#define TPM_ORD_LOADKEY2 65
+#define TPM_LOADKEY2_SIZE 59
+#define TPM_FLUSHSPECIFIC_SIZE 18
+
+#define TPM_RT_KEY 0x00000001
+
+/*
+ * Load a TPM key from the blob provided by userspace
+ */
+static int tpm_loadkey2(struct tpm_buf *tb,
+ uint32_t keyhandle, unsigned char *keyauth,
+ const unsigned char *keyblob, int keybloblen,
+ uint32_t *newhandle)
+{
+ unsigned char nonceodd[TPM_NONCE_SIZE];
+ unsigned char enonce[TPM_NONCE_SIZE];
+ unsigned char authdata[SHA1_DIGEST_SIZE];
+ uint32_t authhandle = 0;
+ unsigned char cont = 0;
+ uint32_t ordinal;
+ int ret;
+
+ ordinal = htonl(TPM_ORD_LOADKEY2);
+
+ /* session for loading the key */
+ ret = oiap(tb, &authhandle, enonce);
+ if (ret < 0) {
+ pr_info("oiap failed (%d)\n", ret);
+ return ret;
+ }
+
+ /* generate odd nonce */
+ ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
+ if (ret < 0) {
+ pr_info("tpm_get_random failed (%d)\n", ret);
+ return ret;
+ }
+
+ /* calculate authorization HMAC value */
+ ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
+ nonceodd, cont, sizeof(uint32_t), &ordinal,
+ keybloblen, keyblob, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ /* build the request buffer */
+ INIT_BUF(tb);
+ store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
+ store32(tb, TPM_LOADKEY2_SIZE + keybloblen);
+ store32(tb, TPM_ORD_LOADKEY2);
+ store32(tb, keyhandle);
+ storebytes(tb, keyblob, keybloblen);
+ store32(tb, authhandle);
+ storebytes(tb, nonceodd, TPM_NONCE_SIZE);
+ store8(tb, cont);
+ storebytes(tb, authdata, SHA1_DIGEST_SIZE);
+
+ ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
+ if (ret < 0) {
+ pr_info("authhmac failed (%d)\n", ret);
+ return ret;
+ }
+
+ ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, keyauth,
+ SHA1_DIGEST_SIZE, 0, 0);
+ if (ret < 0) {
+ pr_info("TSS_checkhmac1 failed (%d)\n", ret);
+ return ret;
+ }
+
+ *newhandle = LOAD32(tb->data, TPM_DATA_OFFSET);
+ return 0;
+}
+
+/*
+ * Execute the FlushSpecific TPM command
+ */
+static int tpm_flushspecific(struct tpm_buf *tb, uint32_t handle)
+{
+ INIT_BUF(tb);
+ store16(tb, TPM_TAG_RQU_COMMAND);
+ store32(tb, TPM_FLUSHSPECIFIC_SIZE);
+ store32(tb, TPM_ORD_FLUSHSPECIFIC);
+ store32(tb, handle);
+ store32(tb, TPM_RT_KEY);
+
+ return trusted_tpm_send(tb->data, MAX_BUF_SIZE);
+}
+
/*
* Maximum buffer size for the BER/DER encoded public key. The public key
* is of the form SEQUENCE { INTEGER n, INTEGER e } where n is a maximum 2048
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