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@@ -0,0 +1,988 @@
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+// SPDX-License-Identifier: GPL-2.0
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+#define pr_fmt(fmt) "ASYM-TPM: "fmt
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+#include <linux/slab.h>
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+#include <linux/module.h>
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+#include <linux/export.h>
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+#include <linux/kernel.h>
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+#include <linux/seq_file.h>
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+#include <linux/scatterlist.h>
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+#include <linux/tpm.h>
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+#include <linux/tpm_command.h>
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+#include <crypto/akcipher.h>
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+#include <crypto/hash.h>
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+#include <crypto/sha.h>
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+#include <asm/unaligned.h>
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+#include <keys/asymmetric-subtype.h>
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+#include <keys/trusted.h>
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+#include <crypto/asym_tpm_subtype.h>
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+#include <crypto/public_key.h>
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+
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+#define TPM_ORD_FLUSHSPECIFIC 186
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+#define TPM_ORD_LOADKEY2 65
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+#define TPM_ORD_UNBIND 30
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+#define TPM_ORD_SIGN 60
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+#define TPM_LOADKEY2_SIZE 59
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+#define TPM_FLUSHSPECIFIC_SIZE 18
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+#define TPM_UNBIND_SIZE 63
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+#define TPM_SIGN_SIZE 63
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+
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+#define TPM_RT_KEY 0x00000001
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+
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+/*
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+ * Load a TPM key from the blob provided by userspace
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+ */
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+static int tpm_loadkey2(struct tpm_buf *tb,
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+ uint32_t keyhandle, unsigned char *keyauth,
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+ const unsigned char *keyblob, int keybloblen,
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+ uint32_t *newhandle)
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+{
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+ unsigned char nonceodd[TPM_NONCE_SIZE];
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+ unsigned char enonce[TPM_NONCE_SIZE];
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+ unsigned char authdata[SHA1_DIGEST_SIZE];
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+ uint32_t authhandle = 0;
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+ unsigned char cont = 0;
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+ uint32_t ordinal;
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+ int ret;
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+
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+ ordinal = htonl(TPM_ORD_LOADKEY2);
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+
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+ /* session for loading the key */
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+ ret = oiap(tb, &authhandle, enonce);
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+ if (ret < 0) {
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+ pr_info("oiap failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ /* generate odd nonce */
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+ ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
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+ if (ret < 0) {
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+ pr_info("tpm_get_random failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ /* calculate authorization HMAC value */
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+ ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
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+ nonceodd, cont, sizeof(uint32_t), &ordinal,
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+ keybloblen, keyblob, 0, 0);
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+ if (ret < 0)
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+ return ret;
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+
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+ /* build the request buffer */
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+ INIT_BUF(tb);
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+ store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
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+ store32(tb, TPM_LOADKEY2_SIZE + keybloblen);
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+ store32(tb, TPM_ORD_LOADKEY2);
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+ store32(tb, keyhandle);
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+ storebytes(tb, keyblob, keybloblen);
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+ store32(tb, authhandle);
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+ storebytes(tb, nonceodd, TPM_NONCE_SIZE);
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+ store8(tb, cont);
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+ storebytes(tb, authdata, SHA1_DIGEST_SIZE);
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+
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+ ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
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+ if (ret < 0) {
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+ pr_info("authhmac failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, keyauth,
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+ SHA1_DIGEST_SIZE, 0, 0);
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+ if (ret < 0) {
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+ pr_info("TSS_checkhmac1 failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ *newhandle = LOAD32(tb->data, TPM_DATA_OFFSET);
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+ return 0;
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+}
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+
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+/*
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+ * Execute the FlushSpecific TPM command
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+ */
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+static int tpm_flushspecific(struct tpm_buf *tb, uint32_t handle)
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+{
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+ INIT_BUF(tb);
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+ store16(tb, TPM_TAG_RQU_COMMAND);
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+ store32(tb, TPM_FLUSHSPECIFIC_SIZE);
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+ store32(tb, TPM_ORD_FLUSHSPECIFIC);
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+ store32(tb, handle);
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+ store32(tb, TPM_RT_KEY);
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+
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+ return trusted_tpm_send(tb->data, MAX_BUF_SIZE);
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+}
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+
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+/*
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+ * Decrypt a blob provided by userspace using a specific key handle.
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+ * The handle is a well known handle or previously loaded by e.g. LoadKey2
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+ */
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+static int tpm_unbind(struct tpm_buf *tb,
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+ uint32_t keyhandle, unsigned char *keyauth,
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+ const unsigned char *blob, uint32_t bloblen,
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+ void *out, uint32_t outlen)
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+{
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+ unsigned char nonceodd[TPM_NONCE_SIZE];
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+ unsigned char enonce[TPM_NONCE_SIZE];
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+ unsigned char authdata[SHA1_DIGEST_SIZE];
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+ uint32_t authhandle = 0;
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+ unsigned char cont = 0;
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+ uint32_t ordinal;
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+ uint32_t datalen;
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+ int ret;
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+
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+ ordinal = htonl(TPM_ORD_UNBIND);
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+ datalen = htonl(bloblen);
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+
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+ /* session for loading the key */
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+ ret = oiap(tb, &authhandle, enonce);
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+ if (ret < 0) {
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+ pr_info("oiap failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ /* generate odd nonce */
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+ ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
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+ if (ret < 0) {
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+ pr_info("tpm_get_random failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ /* calculate authorization HMAC value */
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+ ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
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+ nonceodd, cont, sizeof(uint32_t), &ordinal,
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+ sizeof(uint32_t), &datalen,
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+ bloblen, blob, 0, 0);
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+ if (ret < 0)
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+ return ret;
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+
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+ /* build the request buffer */
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+ INIT_BUF(tb);
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+ store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
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+ store32(tb, TPM_UNBIND_SIZE + bloblen);
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+ store32(tb, TPM_ORD_UNBIND);
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+ store32(tb, keyhandle);
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+ store32(tb, bloblen);
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+ storebytes(tb, blob, bloblen);
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+ store32(tb, authhandle);
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+ storebytes(tb, nonceodd, TPM_NONCE_SIZE);
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+ store8(tb, cont);
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+ storebytes(tb, authdata, SHA1_DIGEST_SIZE);
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+
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+ ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
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+ if (ret < 0) {
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+ pr_info("authhmac failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
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+
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+ ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
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+ keyauth, SHA1_DIGEST_SIZE,
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+ sizeof(uint32_t), TPM_DATA_OFFSET,
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+ datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
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+ 0, 0);
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+ if (ret < 0) {
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+ pr_info("TSS_checkhmac1 failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
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+ min(outlen, datalen));
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+
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+ return datalen;
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+}
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+
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+/*
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+ * Sign a blob provided by userspace (that has had the hash function applied)
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+ * using a specific key handle. The handle is assumed to have been previously
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+ * loaded by e.g. LoadKey2.
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+ *
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+ * Note that the key signature scheme of the used key should be set to
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+ * TPM_SS_RSASSAPKCS1v15_DER. This allows the hashed input to be of any size
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+ * up to key_length_in_bytes - 11 and not be limited to size 20 like the
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+ * TPM_SS_RSASSAPKCS1v15_SHA1 signature scheme.
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+ */
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+static int tpm_sign(struct tpm_buf *tb,
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+ uint32_t keyhandle, unsigned char *keyauth,
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+ const unsigned char *blob, uint32_t bloblen,
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+ void *out, uint32_t outlen)
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+{
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+ unsigned char nonceodd[TPM_NONCE_SIZE];
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+ unsigned char enonce[TPM_NONCE_SIZE];
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+ unsigned char authdata[SHA1_DIGEST_SIZE];
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+ uint32_t authhandle = 0;
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+ unsigned char cont = 0;
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+ uint32_t ordinal;
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+ uint32_t datalen;
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+ int ret;
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+
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+ ordinal = htonl(TPM_ORD_SIGN);
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+ datalen = htonl(bloblen);
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+
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+ /* session for loading the key */
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+ ret = oiap(tb, &authhandle, enonce);
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+ if (ret < 0) {
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+ pr_info("oiap failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ /* generate odd nonce */
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+ ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
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+ if (ret < 0) {
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+ pr_info("tpm_get_random failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ /* calculate authorization HMAC value */
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+ ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
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+ nonceodd, cont, sizeof(uint32_t), &ordinal,
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+ sizeof(uint32_t), &datalen,
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+ bloblen, blob, 0, 0);
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+ if (ret < 0)
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+ return ret;
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+
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+ /* build the request buffer */
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+ INIT_BUF(tb);
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+ store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
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+ store32(tb, TPM_SIGN_SIZE + bloblen);
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+ store32(tb, TPM_ORD_SIGN);
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+ store32(tb, keyhandle);
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+ store32(tb, bloblen);
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+ storebytes(tb, blob, bloblen);
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+ store32(tb, authhandle);
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+ storebytes(tb, nonceodd, TPM_NONCE_SIZE);
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+ store8(tb, cont);
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+ storebytes(tb, authdata, SHA1_DIGEST_SIZE);
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+
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+ ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
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+ if (ret < 0) {
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+ pr_info("authhmac failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
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+
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+ ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
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+ keyauth, SHA1_DIGEST_SIZE,
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+ sizeof(uint32_t), TPM_DATA_OFFSET,
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+ datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
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+ 0, 0);
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+ if (ret < 0) {
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+ pr_info("TSS_checkhmac1 failed (%d)\n", ret);
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+ return ret;
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+ }
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+
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+ memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
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+ min(datalen, outlen));
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+
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+ return datalen;
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+}
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+/*
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+ * Maximum buffer size for the BER/DER encoded public key. The public key
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+ * is of the form SEQUENCE { INTEGER n, INTEGER e } where n is a maximum 2048
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+ * bit key and e is usually 65537
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+ * The encoding overhead is:
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+ * - max 4 bytes for SEQUENCE
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+ * - max 4 bytes for INTEGER n type/length
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+ * - 257 bytes of n
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+ * - max 2 bytes for INTEGER e type/length
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+ * - 3 bytes of e
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+ */
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+#define PUB_KEY_BUF_SIZE (4 + 4 + 257 + 2 + 3)
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+
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+/*
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+ * Provide a part of a description of the key for /proc/keys.
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+ */
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+static void asym_tpm_describe(const struct key *asymmetric_key,
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+ struct seq_file *m)
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+{
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+ struct tpm_key *tk = asymmetric_key->payload.data[asym_crypto];
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+
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+ if (!tk)
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+ return;
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+
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+ seq_printf(m, "TPM1.2/Blob");
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+}
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+
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+static void asym_tpm_destroy(void *payload0, void *payload3)
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+{
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+ struct tpm_key *tk = payload0;
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+
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+ if (!tk)
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+ return;
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+
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+ kfree(tk->blob);
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+ tk->blob_len = 0;
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+
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+ kfree(tk);
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+}
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+
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+/* How many bytes will it take to encode the length */
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+static inline uint32_t definite_length(uint32_t len)
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+{
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+ if (len <= 127)
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+ return 1;
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+ if (len <= 255)
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+ return 2;
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+ return 3;
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+}
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+
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+static inline uint8_t *encode_tag_length(uint8_t *buf, uint8_t tag,
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+ uint32_t len)
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+{
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+ *buf++ = tag;
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+
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+ if (len <= 127) {
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+ buf[0] = len;
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+ return buf + 1;
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+ }
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+
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+ if (len <= 255) {
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+ buf[0] = 0x81;
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+ buf[1] = len;
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+ return buf + 2;
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+ }
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+
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+ buf[0] = 0x82;
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+ put_unaligned_be16(len, buf + 1);
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+ return buf + 3;
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+}
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+
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+static uint32_t derive_pub_key(const void *pub_key, uint32_t len, uint8_t *buf)
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+{
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+ uint8_t *cur = buf;
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+ uint32_t n_len = definite_length(len) + 1 + len + 1;
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+ uint32_t e_len = definite_length(3) + 1 + 3;
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+ uint8_t e[3] = { 0x01, 0x00, 0x01 };
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+
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+ /* SEQUENCE */
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+ cur = encode_tag_length(cur, 0x30, n_len + e_len);
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+ /* INTEGER n */
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+ cur = encode_tag_length(cur, 0x02, len + 1);
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+ cur[0] = 0x00;
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+ memcpy(cur + 1, pub_key, len);
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+ cur += len + 1;
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+ cur = encode_tag_length(cur, 0x02, sizeof(e));
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+ memcpy(cur, e, sizeof(e));
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+ cur += sizeof(e);
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+
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+ return cur - buf;
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+}
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+
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+/*
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+ * Determine the crypto algorithm name.
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+ */
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+static int determine_akcipher(const char *encoding, const char *hash_algo,
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+ char alg_name[CRYPTO_MAX_ALG_NAME])
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+{
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+ if (strcmp(encoding, "pkcs1") == 0) {
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+ if (!hash_algo) {
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+ strcpy(alg_name, "pkcs1pad(rsa)");
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+ return 0;
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+ }
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+
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+ if (snprintf(alg_name, CRYPTO_MAX_ALG_NAME, "pkcs1pad(rsa,%s)",
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+ hash_algo) >= CRYPTO_MAX_ALG_NAME)
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+ return -EINVAL;
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+
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+ return 0;
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+ }
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+
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+ if (strcmp(encoding, "raw") == 0) {
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+ strcpy(alg_name, "rsa");
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+ return 0;
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+ }
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+
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+ return -ENOPKG;
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+}
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+
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+/*
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+ * Query information about a key.
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+ */
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|
|
+static int tpm_key_query(const struct kernel_pkey_params *params,
|
|
|
+ struct kernel_pkey_query *info)
|
|
|
+{
|
|
|
+ struct tpm_key *tk = params->key->payload.data[asym_crypto];
|
|
|
+ int ret;
|
|
|
+ char alg_name[CRYPTO_MAX_ALG_NAME];
|
|
|
+ struct crypto_akcipher *tfm;
|
|
|
+ uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
|
|
|
+ uint32_t der_pub_key_len;
|
|
|
+ int len;
|
|
|
+
|
|
|
+ /* TPM only works on private keys, public keys still done in software */
|
|
|
+ ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
|
|
|
+ if (ret < 0)
|
|
|
+ return ret;
|
|
|
+
|
|
|
+ tfm = crypto_alloc_akcipher(alg_name, 0, 0);
|
|
|
+ if (IS_ERR(tfm))
|
|
|
+ return PTR_ERR(tfm);
|
|
|
+
|
|
|
+ der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
|
|
|
+ der_pub_key);
|
|
|
+
|
|
|
+ ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
|
|
|
+ if (ret < 0)
|
|
|
+ goto error_free_tfm;
|
|
|
+
|
|
|
+ len = crypto_akcipher_maxsize(tfm);
|
|
|
+
|
|
|
+ info->key_size = tk->key_len;
|
|
|
+ info->max_data_size = tk->key_len / 8;
|
|
|
+ info->max_sig_size = len;
|
|
|
+ info->max_enc_size = len;
|
|
|
+ info->max_dec_size = tk->key_len / 8;
|
|
|
+
|
|
|
+ info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT |
|
|
|
+ KEYCTL_SUPPORTS_DECRYPT |
|
|
|
+ KEYCTL_SUPPORTS_VERIFY |
|
|
|
+ KEYCTL_SUPPORTS_SIGN;
|
|
|
+
|
|
|
+ ret = 0;
|
|
|
+error_free_tfm:
|
|
|
+ crypto_free_akcipher(tfm);
|
|
|
+ pr_devel("<==%s() = %d\n", __func__, ret);
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Encryption operation is performed with the public key. Hence it is done
|
|
|
+ * in software
|
|
|
+ */
|
|
|
+static int tpm_key_encrypt(struct tpm_key *tk,
|
|
|
+ struct kernel_pkey_params *params,
|
|
|
+ const void *in, void *out)
|
|
|
+{
|
|
|
+ char alg_name[CRYPTO_MAX_ALG_NAME];
|
|
|
+ struct crypto_akcipher *tfm;
|
|
|
+ struct akcipher_request *req;
|
|
|
+ struct crypto_wait cwait;
|
|
|
+ struct scatterlist in_sg, out_sg;
|
|
|
+ uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
|
|
|
+ uint32_t der_pub_key_len;
|
|
|
+ int ret;
|
|
|
+
|
|
|
+ pr_devel("==>%s()\n", __func__);
|
|
|
+
|
|
|
+ ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
|
|
|
+ if (ret < 0)
|
|
|
+ return ret;
|
|
|
+
|
|
|
+ tfm = crypto_alloc_akcipher(alg_name, 0, 0);
|
|
|
+ if (IS_ERR(tfm))
|
|
|
+ return PTR_ERR(tfm);
|
|
|
+
|
|
|
+ der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
|
|
|
+ der_pub_key);
|
|
|
+
|
|
|
+ ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
|
|
|
+ if (ret < 0)
|
|
|
+ goto error_free_tfm;
|
|
|
+
|
|
|
+ req = akcipher_request_alloc(tfm, GFP_KERNEL);
|
|
|
+ if (!req)
|
|
|
+ goto error_free_tfm;
|
|
|
+
|
|
|
+ sg_init_one(&in_sg, in, params->in_len);
|
|
|
+ sg_init_one(&out_sg, out, params->out_len);
|
|
|
+ akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
|
|
|
+ params->out_len);
|
|
|
+ crypto_init_wait(&cwait);
|
|
|
+ akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
|
|
|
+ CRYPTO_TFM_REQ_MAY_SLEEP,
|
|
|
+ crypto_req_done, &cwait);
|
|
|
+
|
|
|
+ ret = crypto_akcipher_encrypt(req);
|
|
|
+ ret = crypto_wait_req(ret, &cwait);
|
|
|
+
|
|
|
+ if (ret == 0)
|
|
|
+ ret = req->dst_len;
|
|
|
+
|
|
|
+ akcipher_request_free(req);
|
|
|
+error_free_tfm:
|
|
|
+ crypto_free_akcipher(tfm);
|
|
|
+ pr_devel("<==%s() = %d\n", __func__, ret);
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Decryption operation is performed with the private key in the TPM.
|
|
|
+ */
|
|
|
+static int tpm_key_decrypt(struct tpm_key *tk,
|
|
|
+ struct kernel_pkey_params *params,
|
|
|
+ const void *in, void *out)
|
|
|
+{
|
|
|
+ struct tpm_buf *tb;
|
|
|
+ uint32_t keyhandle;
|
|
|
+ uint8_t srkauth[SHA1_DIGEST_SIZE];
|
|
|
+ uint8_t keyauth[SHA1_DIGEST_SIZE];
|
|
|
+ int r;
|
|
|
+
|
|
|
+ pr_devel("==>%s()\n", __func__);
|
|
|
+
|
|
|
+ if (params->hash_algo)
|
|
|
+ return -ENOPKG;
|
|
|
+
|
|
|
+ if (strcmp(params->encoding, "pkcs1"))
|
|
|
+ return -ENOPKG;
|
|
|
+
|
|
|
+ tb = kzalloc(sizeof(*tb), GFP_KERNEL);
|
|
|
+ if (!tb)
|
|
|
+ return -ENOMEM;
|
|
|
+
|
|
|
+ /* TODO: Handle a non-all zero SRK authorization */
|
|
|
+ memset(srkauth, 0, sizeof(srkauth));
|
|
|
+
|
|
|
+ r = tpm_loadkey2(tb, SRKHANDLE, srkauth,
|
|
|
+ tk->blob, tk->blob_len, &keyhandle);
|
|
|
+ if (r < 0) {
|
|
|
+ pr_devel("loadkey2 failed (%d)\n", r);
|
|
|
+ goto error;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* TODO: Handle a non-all zero key authorization */
|
|
|
+ memset(keyauth, 0, sizeof(keyauth));
|
|
|
+
|
|
|
+ r = tpm_unbind(tb, keyhandle, keyauth,
|
|
|
+ in, params->in_len, out, params->out_len);
|
|
|
+ if (r < 0)
|
|
|
+ pr_devel("tpm_unbind failed (%d)\n", r);
|
|
|
+
|
|
|
+ if (tpm_flushspecific(tb, keyhandle) < 0)
|
|
|
+ pr_devel("flushspecific failed (%d)\n", r);
|
|
|
+
|
|
|
+error:
|
|
|
+ kzfree(tb);
|
|
|
+ pr_devel("<==%s() = %d\n", __func__, r);
|
|
|
+ return r;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
|
|
|
+ */
|
|
|
+static const u8 digest_info_md5[] = {
|
|
|
+ 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
|
|
|
+ 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
|
|
|
+ 0x05, 0x00, 0x04, 0x10
|
|
|
+};
|
|
|
+
|
|
|
+static const u8 digest_info_sha1[] = {
|
|
|
+ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
|
|
|
+ 0x2b, 0x0e, 0x03, 0x02, 0x1a,
|
|
|
+ 0x05, 0x00, 0x04, 0x14
|
|
|
+};
|
|
|
+
|
|
|
+static const u8 digest_info_rmd160[] = {
|
|
|
+ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
|
|
|
+ 0x2b, 0x24, 0x03, 0x02, 0x01,
|
|
|
+ 0x05, 0x00, 0x04, 0x14
|
|
|
+};
|
|
|
+
|
|
|
+static const u8 digest_info_sha224[] = {
|
|
|
+ 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
|
|
|
+ 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
|
|
|
+ 0x05, 0x00, 0x04, 0x1c
|
|
|
+};
|
|
|
+
|
|
|
+static const u8 digest_info_sha256[] = {
|
|
|
+ 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
|
|
|
+ 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
|
|
|
+ 0x05, 0x00, 0x04, 0x20
|
|
|
+};
|
|
|
+
|
|
|
+static const u8 digest_info_sha384[] = {
|
|
|
+ 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
|
|
|
+ 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
|
|
|
+ 0x05, 0x00, 0x04, 0x30
|
|
|
+};
|
|
|
+
|
|
|
+static const u8 digest_info_sha512[] = {
|
|
|
+ 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
|
|
|
+ 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
|
|
|
+ 0x05, 0x00, 0x04, 0x40
|
|
|
+};
|
|
|
+
|
|
|
+static const struct asn1_template {
|
|
|
+ const char *name;
|
|
|
+ const u8 *data;
|
|
|
+ size_t size;
|
|
|
+} asn1_templates[] = {
|
|
|
+#define _(X) { #X, digest_info_##X, sizeof(digest_info_##X) }
|
|
|
+ _(md5),
|
|
|
+ _(sha1),
|
|
|
+ _(rmd160),
|
|
|
+ _(sha256),
|
|
|
+ _(sha384),
|
|
|
+ _(sha512),
|
|
|
+ _(sha224),
|
|
|
+ { NULL }
|
|
|
+#undef _
|
|
|
+};
|
|
|
+
|
|
|
+static const struct asn1_template *lookup_asn1(const char *name)
|
|
|
+{
|
|
|
+ const struct asn1_template *p;
|
|
|
+
|
|
|
+ for (p = asn1_templates; p->name; p++)
|
|
|
+ if (strcmp(name, p->name) == 0)
|
|
|
+ return p;
|
|
|
+ return NULL;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Sign operation is performed with the private key in the TPM.
|
|
|
+ */
|
|
|
+static int tpm_key_sign(struct tpm_key *tk,
|
|
|
+ struct kernel_pkey_params *params,
|
|
|
+ const void *in, void *out)
|
|
|
+{
|
|
|
+ struct tpm_buf *tb;
|
|
|
+ uint32_t keyhandle;
|
|
|
+ uint8_t srkauth[SHA1_DIGEST_SIZE];
|
|
|
+ uint8_t keyauth[SHA1_DIGEST_SIZE];
|
|
|
+ void *asn1_wrapped = NULL;
|
|
|
+ uint32_t in_len = params->in_len;
|
|
|
+ int r;
|
|
|
+
|
|
|
+ pr_devel("==>%s()\n", __func__);
|
|
|
+
|
|
|
+ if (strcmp(params->encoding, "pkcs1"))
|
|
|
+ return -ENOPKG;
|
|
|
+
|
|
|
+ if (params->hash_algo) {
|
|
|
+ const struct asn1_template *asn1 =
|
|
|
+ lookup_asn1(params->hash_algo);
|
|
|
+
|
|
|
+ if (!asn1)
|
|
|
+ return -ENOPKG;
|
|
|
+
|
|
|
+ /* request enough space for the ASN.1 template + input hash */
|
|
|
+ asn1_wrapped = kzalloc(in_len + asn1->size, GFP_KERNEL);
|
|
|
+ if (!asn1_wrapped)
|
|
|
+ return -ENOMEM;
|
|
|
+
|
|
|
+ /* Copy ASN.1 template, then the input */
|
|
|
+ memcpy(asn1_wrapped, asn1->data, asn1->size);
|
|
|
+ memcpy(asn1_wrapped + asn1->size, in, in_len);
|
|
|
+
|
|
|
+ in = asn1_wrapped;
|
|
|
+ in_len += asn1->size;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (in_len > tk->key_len / 8 - 11) {
|
|
|
+ r = -EOVERFLOW;
|
|
|
+ goto error_free_asn1_wrapped;
|
|
|
+ }
|
|
|
+
|
|
|
+ r = -ENOMEM;
|
|
|
+ tb = kzalloc(sizeof(*tb), GFP_KERNEL);
|
|
|
+ if (!tb)
|
|
|
+ goto error_free_asn1_wrapped;
|
|
|
+
|
|
|
+ /* TODO: Handle a non-all zero SRK authorization */
|
|
|
+ memset(srkauth, 0, sizeof(srkauth));
|
|
|
+
|
|
|
+ r = tpm_loadkey2(tb, SRKHANDLE, srkauth,
|
|
|
+ tk->blob, tk->blob_len, &keyhandle);
|
|
|
+ if (r < 0) {
|
|
|
+ pr_devel("loadkey2 failed (%d)\n", r);
|
|
|
+ goto error_free_tb;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* TODO: Handle a non-all zero key authorization */
|
|
|
+ memset(keyauth, 0, sizeof(keyauth));
|
|
|
+
|
|
|
+ r = tpm_sign(tb, keyhandle, keyauth, in, in_len, out, params->out_len);
|
|
|
+ if (r < 0)
|
|
|
+ pr_devel("tpm_sign failed (%d)\n", r);
|
|
|
+
|
|
|
+ if (tpm_flushspecific(tb, keyhandle) < 0)
|
|
|
+ pr_devel("flushspecific failed (%d)\n", r);
|
|
|
+
|
|
|
+error_free_tb:
|
|
|
+ kzfree(tb);
|
|
|
+error_free_asn1_wrapped:
|
|
|
+ kfree(asn1_wrapped);
|
|
|
+ pr_devel("<==%s() = %d\n", __func__, r);
|
|
|
+ return r;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Do encryption, decryption and signing ops.
|
|
|
+ */
|
|
|
+static int tpm_key_eds_op(struct kernel_pkey_params *params,
|
|
|
+ const void *in, void *out)
|
|
|
+{
|
|
|
+ struct tpm_key *tk = params->key->payload.data[asym_crypto];
|
|
|
+ int ret = -EOPNOTSUPP;
|
|
|
+
|
|
|
+ /* Perform the encryption calculation. */
|
|
|
+ switch (params->op) {
|
|
|
+ case kernel_pkey_encrypt:
|
|
|
+ ret = tpm_key_encrypt(tk, params, in, out);
|
|
|
+ break;
|
|
|
+ case kernel_pkey_decrypt:
|
|
|
+ ret = tpm_key_decrypt(tk, params, in, out);
|
|
|
+ break;
|
|
|
+ case kernel_pkey_sign:
|
|
|
+ ret = tpm_key_sign(tk, params, in, out);
|
|
|
+ break;
|
|
|
+ default:
|
|
|
+ BUG();
|
|
|
+ }
|
|
|
+
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Verify a signature using a public key.
|
|
|
+ */
|
|
|
+static int tpm_key_verify_signature(const struct key *key,
|
|
|
+ const struct public_key_signature *sig)
|
|
|
+{
|
|
|
+ const struct tpm_key *tk = key->payload.data[asym_crypto];
|
|
|
+ struct crypto_wait cwait;
|
|
|
+ struct crypto_akcipher *tfm;
|
|
|
+ struct akcipher_request *req;
|
|
|
+ struct scatterlist sig_sg, digest_sg;
|
|
|
+ char alg_name[CRYPTO_MAX_ALG_NAME];
|
|
|
+ uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
|
|
|
+ uint32_t der_pub_key_len;
|
|
|
+ void *output;
|
|
|
+ unsigned int outlen;
|
|
|
+ int ret;
|
|
|
+
|
|
|
+ pr_devel("==>%s()\n", __func__);
|
|
|
+
|
|
|
+ BUG_ON(!tk);
|
|
|
+ BUG_ON(!sig);
|
|
|
+ BUG_ON(!sig->s);
|
|
|
+
|
|
|
+ if (!sig->digest)
|
|
|
+ return -ENOPKG;
|
|
|
+
|
|
|
+ ret = determine_akcipher(sig->encoding, sig->hash_algo, alg_name);
|
|
|
+ if (ret < 0)
|
|
|
+ return ret;
|
|
|
+
|
|
|
+ tfm = crypto_alloc_akcipher(alg_name, 0, 0);
|
|
|
+ if (IS_ERR(tfm))
|
|
|
+ return PTR_ERR(tfm);
|
|
|
+
|
|
|
+ der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
|
|
|
+ der_pub_key);
|
|
|
+
|
|
|
+ ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
|
|
|
+ if (ret < 0)
|
|
|
+ goto error_free_tfm;
|
|
|
+
|
|
|
+ ret = -ENOMEM;
|
|
|
+ req = akcipher_request_alloc(tfm, GFP_KERNEL);
|
|
|
+ if (!req)
|
|
|
+ goto error_free_tfm;
|
|
|
+
|
|
|
+ ret = -ENOMEM;
|
|
|
+ outlen = crypto_akcipher_maxsize(tfm);
|
|
|
+ output = kmalloc(outlen, GFP_KERNEL);
|
|
|
+ if (!output)
|
|
|
+ goto error_free_req;
|
|
|
+
|
|
|
+ sg_init_one(&sig_sg, sig->s, sig->s_size);
|
|
|
+ sg_init_one(&digest_sg, output, outlen);
|
|
|
+ akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size,
|
|
|
+ outlen);
|
|
|
+ crypto_init_wait(&cwait);
|
|
|
+ akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
|
|
|
+ CRYPTO_TFM_REQ_MAY_SLEEP,
|
|
|
+ crypto_req_done, &cwait);
|
|
|
+
|
|
|
+ /* Perform the verification calculation. This doesn't actually do the
|
|
|
+ * verification, but rather calculates the hash expected by the
|
|
|
+ * signature and returns that to us.
|
|
|
+ */
|
|
|
+ ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
|
|
|
+ if (ret)
|
|
|
+ goto out_free_output;
|
|
|
+
|
|
|
+ /* Do the actual verification step. */
|
|
|
+ if (req->dst_len != sig->digest_size ||
|
|
|
+ memcmp(sig->digest, output, sig->digest_size) != 0)
|
|
|
+ ret = -EKEYREJECTED;
|
|
|
+
|
|
|
+out_free_output:
|
|
|
+ kfree(output);
|
|
|
+error_free_req:
|
|
|
+ akcipher_request_free(req);
|
|
|
+error_free_tfm:
|
|
|
+ crypto_free_akcipher(tfm);
|
|
|
+ pr_devel("<==%s() = %d\n", __func__, ret);
|
|
|
+ if (WARN_ON_ONCE(ret > 0))
|
|
|
+ ret = -EINVAL;
|
|
|
+ return ret;
|
|
|
+}
|
|
|
+
|
|
|
+/*
|
|
|
+ * Parse enough information out of TPM_KEY structure:
|
|
|
+ * TPM_STRUCT_VER -> 4 bytes
|
|
|
+ * TPM_KEY_USAGE -> 2 bytes
|
|
|
+ * TPM_KEY_FLAGS -> 4 bytes
|
|
|
+ * TPM_AUTH_DATA_USAGE -> 1 byte
|
|
|
+ * TPM_KEY_PARMS -> variable
|
|
|
+ * UINT32 PCRInfoSize -> 4 bytes
|
|
|
+ * BYTE* -> PCRInfoSize bytes
|
|
|
+ * TPM_STORE_PUBKEY
|
|
|
+ * UINT32 encDataSize;
|
|
|
+ * BYTE* -> encDataSize;
|
|
|
+ *
|
|
|
+ * TPM_KEY_PARMS:
|
|
|
+ * TPM_ALGORITHM_ID -> 4 bytes
|
|
|
+ * TPM_ENC_SCHEME -> 2 bytes
|
|
|
+ * TPM_SIG_SCHEME -> 2 bytes
|
|
|
+ * UINT32 parmSize -> 4 bytes
|
|
|
+ * BYTE* -> variable
|
|
|
+ */
|
|
|
+static int extract_key_parameters(struct tpm_key *tk)
|
|
|
+{
|
|
|
+ const void *cur = tk->blob;
|
|
|
+ uint32_t len = tk->blob_len;
|
|
|
+ const void *pub_key;
|
|
|
+ uint32_t sz;
|
|
|
+ uint32_t key_len;
|
|
|
+
|
|
|
+ if (len < 11)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ /* Ensure this is a legacy key */
|
|
|
+ if (get_unaligned_be16(cur + 4) != 0x0015)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ /* Skip to TPM_KEY_PARMS */
|
|
|
+ cur += 11;
|
|
|
+ len -= 11;
|
|
|
+
|
|
|
+ if (len < 12)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ /* Make sure this is an RSA key */
|
|
|
+ if (get_unaligned_be32(cur) != 0x00000001)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ /* Make sure this is TPM_ES_RSAESPKCSv15 encoding scheme */
|
|
|
+ if (get_unaligned_be16(cur + 4) != 0x0002)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ /* Make sure this is TPM_SS_RSASSAPKCS1v15_DER signature scheme */
|
|
|
+ if (get_unaligned_be16(cur + 6) != 0x0003)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ sz = get_unaligned_be32(cur + 8);
|
|
|
+ if (len < sz + 12)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ /* Move to TPM_RSA_KEY_PARMS */
|
|
|
+ len -= 12;
|
|
|
+ cur += 12;
|
|
|
+
|
|
|
+ /* Grab the RSA key length */
|
|
|
+ key_len = get_unaligned_be32(cur);
|
|
|
+
|
|
|
+ switch (key_len) {
|
|
|
+ case 512:
|
|
|
+ case 1024:
|
|
|
+ case 1536:
|
|
|
+ case 2048:
|
|
|
+ break;
|
|
|
+ default:
|
|
|
+ return -EINVAL;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Move just past TPM_KEY_PARMS */
|
|
|
+ cur += sz;
|
|
|
+ len -= sz;
|
|
|
+
|
|
|
+ if (len < 4)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ sz = get_unaligned_be32(cur);
|
|
|
+ if (len < 4 + sz)
|
|
|
+ return -EBADMSG;
|
|
|
+
|
|
|
+ /* Move to TPM_STORE_PUBKEY */
|
|
|
+ cur += 4 + sz;
|
|
|
+ len -= 4 + sz;
|
|
|
+
|
|
|
+ /* Grab the size of the public key, it should jive with the key size */
|
|
|
+ sz = get_unaligned_be32(cur);
|
|
|
+ if (sz > 256)
|
|
|
+ return -EINVAL;
|
|
|
+
|
|
|
+ pub_key = cur + 4;
|
|
|
+
|
|
|
+ tk->key_len = key_len;
|
|
|
+ tk->pub_key = pub_key;
|
|
|
+ tk->pub_key_len = sz;
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+/* Given the blob, parse it and load it into the TPM */
|
|
|
+struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len)
|
|
|
+{
|
|
|
+ int r;
|
|
|
+ struct tpm_key *tk;
|
|
|
+
|
|
|
+ r = tpm_is_tpm2(NULL);
|
|
|
+ if (r < 0)
|
|
|
+ goto error;
|
|
|
+
|
|
|
+ /* We don't support TPM2 yet */
|
|
|
+ if (r > 0) {
|
|
|
+ r = -ENODEV;
|
|
|
+ goto error;
|
|
|
+ }
|
|
|
+
|
|
|
+ r = -ENOMEM;
|
|
|
+ tk = kzalloc(sizeof(struct tpm_key), GFP_KERNEL);
|
|
|
+ if (!tk)
|
|
|
+ goto error;
|
|
|
+
|
|
|
+ tk->blob = kmemdup(blob, blob_len, GFP_KERNEL);
|
|
|
+ if (!tk->blob)
|
|
|
+ goto error_memdup;
|
|
|
+
|
|
|
+ tk->blob_len = blob_len;
|
|
|
+
|
|
|
+ r = extract_key_parameters(tk);
|
|
|
+ if (r < 0)
|
|
|
+ goto error_extract;
|
|
|
+
|
|
|
+ return tk;
|
|
|
+
|
|
|
+error_extract:
|
|
|
+ kfree(tk->blob);
|
|
|
+ tk->blob_len = 0;
|
|
|
+error_memdup:
|
|
|
+ kfree(tk);
|
|
|
+error:
|
|
|
+ return ERR_PTR(r);
|
|
|
+}
|
|
|
+EXPORT_SYMBOL_GPL(tpm_key_create);
|
|
|
+
|
|
|
+/*
|
|
|
+ * TPM-based asymmetric key subtype
|
|
|
+ */
|
|
|
+struct asymmetric_key_subtype asym_tpm_subtype = {
|
|
|
+ .owner = THIS_MODULE,
|
|
|
+ .name = "asym_tpm",
|
|
|
+ .name_len = sizeof("asym_tpm") - 1,
|
|
|
+ .describe = asym_tpm_describe,
|
|
|
+ .destroy = asym_tpm_destroy,
|
|
|
+ .query = tpm_key_query,
|
|
|
+ .eds_op = tpm_key_eds_op,
|
|
|
+ .verify_signature = tpm_key_verify_signature,
|
|
|
+};
|
|
|
+EXPORT_SYMBOL_GPL(asym_tpm_subtype);
|
|
|
+
|
|
|
+MODULE_DESCRIPTION("TPM based asymmetric key subtype");
|
|
|
+MODULE_AUTHOR("Intel Corporation");
|
|
|
+MODULE_LICENSE("GPL v2");
|