KEYS: asym_tpm: Add loadkey2 and flushspecific [ver #2]

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>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

1 files changed, 94 insertions, 0 deletions

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