* [PATCH RFC v2 1/5] crypto: rsa-pkcs1pad: export rsa1_asn_lookup()
2024-05-19 0:25 [PATCH RFC v2 0/5] Asymmetric TPM2 key type Jarkko Sakkinen
@ 2024-05-19 0:25 ` Jarkko Sakkinen
2024-05-19 0:25 ` [PATCH RFC v2 2/5] tpm: export tpm2_load_context() Jarkko Sakkinen
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Jarkko Sakkinen @ 2024-05-19 0:25 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Jarkko Sakkinen, David Howells, David S. Miller,
Peter Huewe, Jason Gunthorpe, James Bottomley, Stefan Berger,
Ard Biesheuvel, Mario Limonciello, open list:CRYPTO API,
open list
ASN.1 template is required for TPM2 asymmetric keys, as it needs to be
piggy-packed with the input data before applying TPM2_RSA_Decrypt. This
patch prepares crypto subsystem for the addition of those keys.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
crypto/rsa-pkcs1pad.c | 16 ++++++++++------
include/crypto/rsa-pkcs1pad.h | 20 ++++++++++++++++++++
2 files changed, 30 insertions(+), 6 deletions(-)
create mode 100644 include/crypto/rsa-pkcs1pad.h
diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index cd501195f34a..00b6c14f861c 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -7,6 +7,7 @@
#include <crypto/algapi.h>
#include <crypto/akcipher.h>
+#include <crypto/rsa-pkcs1pad.h>
#include <crypto/internal/akcipher.h>
#include <crypto/internal/rsa.h>
#include <linux/err.h>
@@ -79,11 +80,7 @@ static const u8 rsa_digest_info_sha3_512[] = {
0x05, 0x00, 0x04, 0x40
};
-static const struct rsa_asn1_template {
- const char *name;
- const u8 *data;
- size_t size;
-} rsa_asn1_templates[] = {
+static const struct rsa_asn1_template rsa_asn1_templates[] = {
#define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
_(md5),
_(sha1),
@@ -101,7 +98,13 @@ static const struct rsa_asn1_template {
{ NULL }
};
-static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
+/**
+ * rsa_lookup_asn1() - Lookup the ASN.1 digest info given the hash
+ * name: hash algorithm name
+ *
+ * Returns the ASN.1 digest info on success, and NULL on failure.
+ */
+const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
{
const struct rsa_asn1_template *p;
@@ -110,6 +113,7 @@ static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
return p;
return NULL;
}
+EXPORT_SYMBOL_GPL(rsa_lookup_asn1);
struct pkcs1pad_ctx {
struct crypto_akcipher *child;
diff --git a/include/crypto/rsa-pkcs1pad.h b/include/crypto/rsa-pkcs1pad.h
new file mode 100644
index 000000000000..32c7453ff644
--- /dev/null
+++ b/include/crypto/rsa-pkcs1pad.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * RSA padding templates.
+ */
+
+#ifndef _CRYPTO_RSA_PKCS1PAD_H
+#define _CRYPTO_RSA_PKCS1PAD_H
+
+/*
+ * Hash algorithm name to ASN.1 template mapping.
+ */
+struct rsa_asn1_template {
+ const char *name;
+ const u8 *data;
+ size_t size;
+};
+
+const struct rsa_asn1_template *rsa_lookup_asn1(const char *name);
+
+#endif /* _CRYPTO_RSA_PKCS1PAD_H */
--
2.45.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RFC v2 2/5] tpm: export tpm2_load_context()
2024-05-19 0:25 [PATCH RFC v2 0/5] Asymmetric TPM2 key type Jarkko Sakkinen
2024-05-19 0:25 ` [PATCH RFC v2 1/5] crypto: rsa-pkcs1pad: export rsa1_asn_lookup() Jarkko Sakkinen
@ 2024-05-19 0:25 ` Jarkko Sakkinen
2024-05-19 0:25 ` [PATCH RFC v2 3/5] KEYS: trusted: Do not use WARN when encode fails Jarkko Sakkinen
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Jarkko Sakkinen @ 2024-05-19 0:25 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Jarkko Sakkinen, David Howells, David S. Miller,
Peter Huewe, Jason Gunthorpe, James Bottomley, Stefan Berger,
Ard Biesheuvel, Mario Limonciello, open list:CRYPTO API,
open list
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
drivers/char/tpm/tpm.h | 2 -
drivers/char/tpm/tpm2-cmd.c | 77 +++++++++++++++++++++++++++++++++++
drivers/char/tpm/tpm2-space.c | 61 ---------------------------
include/linux/tpm.h | 2 +
4 files changed, 79 insertions(+), 63 deletions(-)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 6b8b9956ba69..c9c67fe84f33 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -314,8 +314,6 @@ int tpm_devs_add(struct tpm_chip *chip);
void tpm_devs_remove(struct tpm_chip *chip);
int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
unsigned int buf_size, unsigned int *offset);
-int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
- unsigned int *offset, u32 *handle);
void tpm_bios_log_setup(struct tpm_chip *chip);
void tpm_bios_log_teardown(struct tpm_chip *chip);
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 0cdf892ec2a7..eb07a109e2ba 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -370,6 +370,83 @@ void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
}
EXPORT_SYMBOL_GPL(tpm2_flush_context);
+struct tpm2_context {
+ __be64 sequence;
+ __be32 saved_handle;
+ __be32 hierarchy;
+ __be16 blob_size;
+} __packed;
+
+/**
+ * tpm2_load_context() - Load TPM2 object to the TPM memory
+ * @chip: TPM chip to use
+ * @buf: Blob containing TPM2 object.
+ * @offset: Output variable for the offset in @buf reached.
+ * @handle: Output variable for the handle of the object in TPM memory.
+ *
+ * Load a blob encrypted with TPM from the memory to the TPM chip.
+ *
+ * Return:
+ * - 0 when the blob is successfully loaded to the TPM.
+ * - -EFAULT if the TPM chip itself fails.
+ * - -ENOENT if the TPM object is replayed.
+ * - -EINVAL if the TPM object is corrupted.
+ */
+int tpm2_load_context(struct tpm_chip *chip, const u8 *buf,
+ unsigned int *offset, u32 *handle)
+{
+ struct tpm_buf tbuf;
+ struct tpm2_context *ctx;
+ unsigned int body_size;
+ int rc;
+
+ rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_LOAD);
+ if (rc)
+ return rc;
+
+ ctx = (struct tpm2_context *)&buf[*offset];
+ body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
+ tpm_buf_append(&tbuf, &buf[*offset], body_size);
+
+ rc = tpm_transmit_cmd(chip, &tbuf, 4, NULL);
+ if (rc < 0) {
+ dev_warn(&chip->dev, "%s: failed with a system error %d\n",
+ __func__, rc);
+ tpm_buf_destroy(&tbuf);
+ return -EFAULT;
+ } else if (tpm2_rc_value(rc) == TPM2_RC_HANDLE ||
+ rc == TPM2_RC_REFERENCE_H0) {
+ /*
+ * TPM_RC_HANDLE means that the session context can't
+ * be loaded because of an internal counter mismatch
+ * that makes the TPM think there might have been a
+ * replay. This might happen if the context was saved
+ * and loaded outside the space.
+ *
+ * TPM_RC_REFERENCE_H0 means the session has been
+ * flushed outside the space
+ */
+ *handle = 0;
+ tpm_buf_destroy(&tbuf);
+ return -ENOENT;
+ } else if (tpm2_rc_value(rc) == TPM2_RC_INTEGRITY) {
+ tpm_buf_destroy(&tbuf);
+ return -EINVAL;
+ } else if (rc > 0) {
+ dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
+ __func__, rc);
+ tpm_buf_destroy(&tbuf);
+ return -EFAULT;
+ }
+
+ *handle = be32_to_cpup((__be32 *)&tbuf.data[TPM_HEADER_SIZE]);
+ *offset += body_size;
+
+ tpm_buf_destroy(&tbuf);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tpm2_load_context);
+
struct tpm2_get_cap_out {
u8 more_data;
__be32 subcap_id;
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 4892d491da8d..708c6e4d64cd 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -21,13 +21,6 @@ enum tpm2_handle_types {
TPM2_HT_TRANSIENT = 0x80000000,
};
-struct tpm2_context {
- __be64 sequence;
- __be32 saved_handle;
- __be32 hierarchy;
- __be16 blob_size;
-} __packed;
-
static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space)
{
int i;
@@ -68,60 +61,6 @@ void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space)
kfree(space->session_buf);
}
-int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
- unsigned int *offset, u32 *handle)
-{
- struct tpm_buf tbuf;
- struct tpm2_context *ctx;
- unsigned int body_size;
- int rc;
-
- rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_LOAD);
- if (rc)
- return rc;
-
- ctx = (struct tpm2_context *)&buf[*offset];
- body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size);
- tpm_buf_append(&tbuf, &buf[*offset], body_size);
-
- rc = tpm_transmit_cmd(chip, &tbuf, 4, NULL);
- if (rc < 0) {
- dev_warn(&chip->dev, "%s: failed with a system error %d\n",
- __func__, rc);
- tpm_buf_destroy(&tbuf);
- return -EFAULT;
- } else if (tpm2_rc_value(rc) == TPM2_RC_HANDLE ||
- rc == TPM2_RC_REFERENCE_H0) {
- /*
- * TPM_RC_HANDLE means that the session context can't
- * be loaded because of an internal counter mismatch
- * that makes the TPM think there might have been a
- * replay. This might happen if the context was saved
- * and loaded outside the space.
- *
- * TPM_RC_REFERENCE_H0 means the session has been
- * flushed outside the space
- */
- *handle = 0;
- tpm_buf_destroy(&tbuf);
- return -ENOENT;
- } else if (tpm2_rc_value(rc) == TPM2_RC_INTEGRITY) {
- tpm_buf_destroy(&tbuf);
- return -EINVAL;
- } else if (rc > 0) {
- dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
- __func__, rc);
- tpm_buf_destroy(&tbuf);
- return -EFAULT;
- }
-
- *handle = be32_to_cpup((__be32 *)&tbuf.data[TPM_HEADER_SIZE]);
- *offset += body_size;
-
- tpm_buf_destroy(&tbuf);
- return 0;
-}
-
int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf,
unsigned int buf_size, unsigned int *offset)
{
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index c17e4efbb2e5..2f25ca07127b 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -466,6 +466,8 @@ extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max);
extern struct tpm_chip *tpm_default_chip(void);
void tpm2_flush_context(struct tpm_chip *chip, u32 handle);
+int tpm2_load_context(struct tpm_chip *chip, const u8 *buf,
+ unsigned int *offset, u32 *handle);
static inline void tpm_buf_append_empty_auth(struct tpm_buf *buf, u32 handle)
{
--
2.45.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RFC v2 3/5] KEYS: trusted: Do not use WARN when encode fails
2024-05-19 0:25 [PATCH RFC v2 0/5] Asymmetric TPM2 key type Jarkko Sakkinen
2024-05-19 0:25 ` [PATCH RFC v2 1/5] crypto: rsa-pkcs1pad: export rsa1_asn_lookup() Jarkko Sakkinen
2024-05-19 0:25 ` [PATCH RFC v2 2/5] tpm: export tpm2_load_context() Jarkko Sakkinen
@ 2024-05-19 0:25 ` Jarkko Sakkinen
2024-05-19 0:25 ` [PATCH RFC v2 4/5] KEYS: trusted: Migrate tpm2_key_{encode,decode}() to TPM driver Jarkko Sakkinen
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Jarkko Sakkinen @ 2024-05-19 0:25 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Jarkko Sakkinen, David Howells, David S. Miller,
Peter Huewe, Jason Gunthorpe, James Bottomley, Stefan Berger,
Ard Biesheuvel, Mario Limonciello, open list:CRYPTO API,
open list, stable, Mimi Zohar, Paul Moore, James Morris,
Serge E. Hallyn, open list:SECURITY SUBSYSTEM
When asn1_encode_sequence() fails, WARN is not the correct solution.
1. asn1_encode_sequence() is not an internal function (located
in lib/asn1_encode.c).
2. Location is known, which makes the stack trace useless.
3. Results a crash if panic_on_warn is set.
It is also noteworthy that the use of WARN is undocumented, and it
should be avoided unless there is a carefully considered rationale to
use it.
Replace WARN with pr_err, and print the return value instead, which is
only useful piece of information.
Cc: stable@vger.kernel.org # v5.13+
Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
security/keys/trusted-keys/trusted_tpm2.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index dfeec06301ce..dbdd6a318b8b 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -38,6 +38,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
u8 *end_work = scratch + SCRATCH_SIZE;
u8 *priv, *pub;
u16 priv_len, pub_len;
+ int ret;
priv_len = get_unaligned_be16(src) + 2;
priv = src;
@@ -79,8 +80,11 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
work1 = payload->blob;
work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
scratch, work - scratch);
- if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
- return PTR_ERR(work1);
+ if (IS_ERR(work1)) {
+ ret = PTR_ERR(work1);
+ pr_err("ASN.1 encode error %d\n", ret);
+ return ret;
+ }
return work1 - payload->blob;
}
--
2.45.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RFC v2 4/5] KEYS: trusted: Migrate tpm2_key_{encode,decode}() to TPM driver
2024-05-19 0:25 [PATCH RFC v2 0/5] Asymmetric TPM2 key type Jarkko Sakkinen
` (2 preceding siblings ...)
2024-05-19 0:25 ` [PATCH RFC v2 3/5] KEYS: trusted: Do not use WARN when encode fails Jarkko Sakkinen
@ 2024-05-19 0:25 ` Jarkko Sakkinen
2024-05-19 0:25 ` [PATCH RFC v2 5/5] keys: asymmetric: ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE Jarkko Sakkinen
2024-05-19 12:49 ` [PATCH RFC v2 0/5] Asymmetric TPM2 key type Jarkko Sakkinen
5 siblings, 0 replies; 7+ messages in thread
From: Jarkko Sakkinen @ 2024-05-19 0:25 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Jarkko Sakkinen, David Howells, David S. Miller,
Peter Huewe, Jason Gunthorpe, James Bottomley, Stefan Berger,
Ard Biesheuvel, Mario Limonciello, open list:CRYPTO API,
open list, Mimi Zohar, Paul Moore, James Morris, Serge E. Hallyn,
open list:SECURITY SUBSYSTEM
Migrate tpm2_key_{encode,decode}() to TPM driver and export the symbols
to make them callable from trusted keys.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
drivers/char/tpm/Kconfig | 5 +
drivers/char/tpm/Makefile | 5 +
drivers/char/tpm/tpm2_key.c | 181 +++++++++++++++++
.../char/tpm}/tpm2key.asn1 | 0
include/crypto/tpm2_key.h | 33 ++++
security/keys/trusted-keys/Makefile | 2 -
security/keys/trusted-keys/trusted_tpm2.c | 187 ++----------------
7 files changed, 242 insertions(+), 171 deletions(-)
create mode 100644 drivers/char/tpm/tpm2_key.c
rename {security/keys/trusted-keys => drivers/char/tpm}/tpm2key.asn1 (100%)
create mode 100644 include/crypto/tpm2_key.h
diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index db41301e63f2..d5d06cc96932 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -3,10 +3,15 @@
# TPM device configuration
#
+config TCG_TPM2_KEY
+ bool
+
menuconfig TCG_TPM
tristate "TPM Hardware Support"
depends on HAS_IOMEM
imply SECURITYFS
+ select ASN1
+ select ASN1_ENCODER
select CRYPTO
select CRYPTO_HASH_INFO
help
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 4c695b0388f3..071437058ef6 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -17,6 +17,11 @@ tpm-y += eventlog/tpm1.o
tpm-y += eventlog/tpm2.o
tpm-y += tpm-buf.o
+# TPM2 Asymmetric Key
+$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h
+tpm-y += tpm2key.asn1.o
+tpm-y += tpm2_key.o
+
tpm-$(CONFIG_TCG_TPM2_HMAC) += tpm2-sessions.o
tpm-$(CONFIG_ACPI) += tpm_ppi.o eventlog/acpi.o
tpm-$(CONFIG_EFI) += eventlog/efi.o
diff --git a/drivers/char/tpm/tpm2_key.c b/drivers/char/tpm/tpm2_key.c
new file mode 100644
index 000000000000..e09441efb0f0
--- /dev/null
+++ b/drivers/char/tpm/tpm2_key.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#define pr_fmt(fmt) "tpm2_key: "fmt
+
+#include <linux/asn1_encoder.h>
+#include <linux/asn1_decoder.h>
+#include <linux/oid_registry.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <crypto/tpm2_key.h>
+#include <asm/unaligned.h>
+#include <keys/trusted-type.h>
+#include "tpm2key.asn1.h"
+
+static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 };
+
+int tpm2_key_parent(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key *ctx = context;
+ const u8 *v = value;
+ int i;
+
+ ctx->parent = 0;
+ for (i = 0; i < vlen; i++) {
+ ctx->parent <<= 8;
+ ctx->parent |= v[i];
+ }
+
+ return 0;
+}
+
+int tpm2_key_type(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ enum OID oid = look_up_OID(value, vlen);
+
+ if (oid != OID_TPMSealedData) {
+ char buffer[50];
+
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_debug("OID is \"%s\" which is not TPMSealedData\n",
+ buffer);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int tpm2_key_pub(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key *ctx = context;
+
+ ctx->pub = value;
+ ctx->pub_len = vlen;
+
+ return 0;
+}
+
+int tpm2_key_priv(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key *ctx = context;
+
+ ctx->priv = value;
+ ctx->priv_len = vlen;
+
+ return 0;
+}
+
+/**
+ * tpm2_key_encode() - Encode TPM2 ASN.1 key.
+ * @blob: Decoded blob.
+ * @blob_auth_len: Authorization length.
+ * @key_handle: TPM2 handle of the key.
+ * @src: ASN.1 source.
+ *
+ * Encodes TPM2 ASN.1 key on success. Returns POSIX error code on failure.
+ */
+int tpm2_key_encode(u8 *blob, u32 blob_auth_len, u32 key_handle, u8 *src)
+{
+ const int SCRATCH_SIZE = PAGE_SIZE;
+ u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
+ u8 *work = scratch, *work1;
+ u8 *end_work = scratch + SCRATCH_SIZE;
+ u8 *priv, *pub;
+ u16 priv_len, pub_len;
+ int ret;
+
+ priv_len = get_unaligned_be16(src) + 2;
+ priv = src;
+
+ src += priv_len;
+
+ pub_len = get_unaligned_be16(src) + 2;
+ pub = src;
+
+ if (!scratch)
+ return -ENOMEM;
+
+ work = asn1_encode_oid(work, end_work, tpm2key_oid,
+ asn1_oid_len(tpm2key_oid));
+
+ if (blob_auth_len == 0) {
+ unsigned char bool[3], *w = bool;
+ /* tag 0 is emptyAuth */
+ w = asn1_encode_boolean(w, w + sizeof(bool), true);
+ if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
+ return PTR_ERR(w);
+ work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
+ }
+
+ /*
+ * Assume both octet strings will encode to a 2 byte definite length
+ *
+ * Note: For a well behaved TPM, this warning should never
+ * trigger, so if it does there's something nefarious going on
+ */
+ if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
+ "BUG: scratch buffer is too small"))
+ return -EINVAL;
+
+ work = asn1_encode_integer(work, end_work, key_handle);
+ work = asn1_encode_octet_string(work, end_work, pub, pub_len);
+ work = asn1_encode_octet_string(work, end_work, priv, priv_len);
+
+ work1 = blob;
+ work1 = asn1_encode_sequence(work1, work1 + MAX_BLOB_SIZE, scratch, work - scratch);
+ if (IS_ERR(work1)) {
+ ret = PTR_ERR(work1);
+ pr_err("ASN.1 encoder failed with %d\n", ret);
+ return ret;
+ }
+
+ return work1 - blob;
+}
+EXPORT_SYMBOL_GPL(tpm2_key_encode);
+
+/**
+ * tpm_key_decode() - Decode TPM2 ASN.1 key.
+ * @src: ASN.1 source.
+ * @src_len: ASN.1 source length.
+ * @key: TPM2 asymmetric key.
+ * @max_key_len: Maximum length of the TPM2 asymmetric key.
+ *
+ * Decodes TPM2 ASN.1 key on success. Returns POSIX error code on failure.
+ */
+int tpm2_key_decode(const u8 *src, u32 src_len, struct tpm2_key *key,
+ u32 max_key_len)
+{
+ struct tpm2_key ctx;
+ int ret;
+
+ memset(&ctx, 0, sizeof(ctx));
+
+ ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, src, src_len);
+ if (ret < 0)
+ return ret;
+
+ if (ctx.priv_len + ctx.pub_len > max_key_len)
+ return -EINVAL;
+
+ ctx.priv = kmemdup(ctx.priv, ctx.priv_len, GFP_KERNEL);
+ if (!ctx.priv)
+ return -ENOMEM;
+
+ ctx.pub = kmemdup(ctx.pub, ctx.pub_len, GFP_KERNEL);
+ if (!ctx.pub) {
+ kfree(ctx.priv);
+ return -ENOMEM;
+ }
+
+ memcpy(key, &ctx, sizeof(ctx));
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tpm2_key_decode);
diff --git a/security/keys/trusted-keys/tpm2key.asn1 b/drivers/char/tpm/tpm2key.asn1
similarity index 100%
rename from security/keys/trusted-keys/tpm2key.asn1
rename to drivers/char/tpm/tpm2key.asn1
diff --git a/include/crypto/tpm2_key.h b/include/crypto/tpm2_key.h
new file mode 100644
index 000000000000..e5d3330afef5
--- /dev/null
+++ b/include/crypto/tpm2_key.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __LINUX_TPM2_KEY_H__
+#define __LINUX_TPM2_KEY_H__
+
+#include <linux/slab.h>
+
+/*
+ * TPM2 ASN.1 key
+ */
+struct tpm2_key {
+ u32 parent;
+ const u8 *pub;
+ u32 pub_len;
+ const u8 *priv;
+ u32 priv_len;
+};
+
+int tpm2_key_encode(u8 *blob, u32 blob_auth_len, u32 key_handle, u8 *src);
+int tpm2_key_decode(const u8 *src, u32 src_len, struct tpm2_key *key,
+ u32 max_key_len);
+
+/**
+ * tpm2_key_free() - Release TPM2 asymmetric key resources and reset values
+ * @key: TPM2 asymmetric key.
+ */
+static inline void tpm2_key_destroy(struct tpm2_key *key)
+{
+ kfree(key->priv);
+ kfree(key->pub);
+ memset(key, 0, sizeof(*key));
+}
+
+#endif /* __LINUX_TPM2_KEY_H__ */
diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile
index f0f3b27f688b..2674d5c10fc9 100644
--- a/security/keys/trusted-keys/Makefile
+++ b/security/keys/trusted-keys/Makefile
@@ -7,9 +7,7 @@ obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
trusted-y += trusted_core.o
trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm1.o
-$(obj)/trusted_tpm2.o: $(obj)/tpm2key.asn1.h
trusted-$(CONFIG_TRUSTED_KEYS_TPM) += trusted_tpm2.o
-trusted-$(CONFIG_TRUSTED_KEYS_TPM) += tpm2key.asn1.o
trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index dbdd6a318b8b..3e1140914ca4 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -13,11 +13,10 @@
#include <keys/trusted-type.h>
#include <keys/trusted_tpm.h>
+#include <crypto/tpm2_key.h>
#include <asm/unaligned.h>
-#include "tpm2key.asn1.h"
-
static struct tpm2_hash tpm2_hash_map[] = {
{HASH_ALGO_SHA1, TPM_ALG_SHA1},
{HASH_ALGO_SHA256, TPM_ALG_SHA256},
@@ -26,169 +25,6 @@ static struct tpm2_hash tpm2_hash_map[] = {
{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
};
-static u32 tpm2key_oid[] = { 2, 23, 133, 10, 1, 5 };
-
-static int tpm2_key_encode(struct trusted_key_payload *payload,
- struct trusted_key_options *options,
- u8 *src, u32 len)
-{
- const int SCRATCH_SIZE = PAGE_SIZE;
- u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
- u8 *work = scratch, *work1;
- u8 *end_work = scratch + SCRATCH_SIZE;
- u8 *priv, *pub;
- u16 priv_len, pub_len;
- int ret;
-
- priv_len = get_unaligned_be16(src) + 2;
- priv = src;
-
- src += priv_len;
-
- pub_len = get_unaligned_be16(src) + 2;
- pub = src;
-
- if (!scratch)
- return -ENOMEM;
-
- work = asn1_encode_oid(work, end_work, tpm2key_oid,
- asn1_oid_len(tpm2key_oid));
-
- if (options->blobauth_len == 0) {
- unsigned char bool[3], *w = bool;
- /* tag 0 is emptyAuth */
- w = asn1_encode_boolean(w, w + sizeof(bool), true);
- if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
- return PTR_ERR(w);
- work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
- }
-
- /*
- * Assume both octet strings will encode to a 2 byte definite length
- *
- * Note: For a well behaved TPM, this warning should never
- * trigger, so if it does there's something nefarious going on
- */
- if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
- "BUG: scratch buffer is too small"))
- return -EINVAL;
-
- work = asn1_encode_integer(work, end_work, options->keyhandle);
- work = asn1_encode_octet_string(work, end_work, pub, pub_len);
- work = asn1_encode_octet_string(work, end_work, priv, priv_len);
-
- work1 = payload->blob;
- work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
- scratch, work - scratch);
- if (IS_ERR(work1)) {
- ret = PTR_ERR(work1);
- pr_err("ASN.1 encode error %d\n", ret);
- return ret;
- }
-
- return work1 - payload->blob;
-}
-
-struct tpm2_key_context {
- u32 parent;
- const u8 *pub;
- u32 pub_len;
- const u8 *priv;
- u32 priv_len;
-};
-
-static int tpm2_key_decode(struct trusted_key_payload *payload,
- struct trusted_key_options *options,
- u8 **buf)
-{
- int ret;
- struct tpm2_key_context ctx;
- u8 *blob;
-
- memset(&ctx, 0, sizeof(ctx));
-
- ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, payload->blob,
- payload->blob_len);
- if (ret < 0)
- return ret;
-
- if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE)
- return -EINVAL;
-
- blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL);
- if (!blob)
- return -ENOMEM;
-
- *buf = blob;
- options->keyhandle = ctx.parent;
-
- memcpy(blob, ctx.priv, ctx.priv_len);
- blob += ctx.priv_len;
-
- memcpy(blob, ctx.pub, ctx.pub_len);
-
- return 0;
-}
-
-int tpm2_key_parent(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
-{
- struct tpm2_key_context *ctx = context;
- const u8 *v = value;
- int i;
-
- ctx->parent = 0;
- for (i = 0; i < vlen; i++) {
- ctx->parent <<= 8;
- ctx->parent |= v[i];
- }
-
- return 0;
-}
-
-int tpm2_key_type(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
-{
- enum OID oid = look_up_OID(value, vlen);
-
- if (oid != OID_TPMSealedData) {
- char buffer[50];
-
- sprint_oid(value, vlen, buffer, sizeof(buffer));
- pr_debug("OID is \"%s\" which is not TPMSealedData\n",
- buffer);
- return -EINVAL;
- }
-
- return 0;
-}
-
-int tpm2_key_pub(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
-{
- struct tpm2_key_context *ctx = context;
-
- ctx->pub = value;
- ctx->pub_len = vlen;
-
- return 0;
-}
-
-int tpm2_key_priv(void *context, size_t hdrlen,
- unsigned char tag,
- const void *value, size_t vlen)
-{
- struct tpm2_key_context *ctx = context;
-
- ctx->priv = value;
- ctx->priv_len = vlen;
-
- return 0;
-}
-
/**
* tpm2_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
*
@@ -338,7 +174,8 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
goto out;
}
- blob_len = tpm2_key_encode(payload, options, &buf.data[offset], blob_len);
+ blob_len = tpm2_key_encode(payload->blob, options->blobauth_len,
+ options->keyhandle, &buf.data[offset]);
out:
tpm_buf_destroy(&sized);
@@ -378,20 +215,32 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
struct trusted_key_options *options,
u32 *blob_handle)
{
- struct tpm_buf buf;
unsigned int private_len;
unsigned int public_len;
unsigned int blob_len;
+ struct tpm2_key key;
+ struct tpm_buf buf;
u8 *blob, *pub;
int rc;
u32 attrs;
- rc = tpm2_key_decode(payload, options, &blob);
+ rc = tpm2_key_decode(payload->blob, payload->blob_len, &key,
+ MAX_BLOB_SIZE);
if (rc) {
- /* old form */
+ /* legacy format: */
blob = payload->blob;
payload->old_format = 1;
+ } else {
+ blob = kmalloc(key.priv_len + key.pub_len + 4, GFP_KERNEL);
+ if (blob) {
+ options->keyhandle = key.parent;
+ memcpy(blob, key.priv, key.priv_len);
+ memcpy(&blob[key.priv_len], key.pub, key.pub_len);
+ }
}
+ tpm2_key_destroy(&key);
+ if (!blob)
+ return -ENOMEM;
/* new format carries keyhandle but old format doesn't */
if (!options->keyhandle)
--
2.45.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH RFC v2 5/5] keys: asymmetric: ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE
2024-05-19 0:25 [PATCH RFC v2 0/5] Asymmetric TPM2 key type Jarkko Sakkinen
` (3 preceding siblings ...)
2024-05-19 0:25 ` [PATCH RFC v2 4/5] KEYS: trusted: Migrate tpm2_key_{encode,decode}() to TPM driver Jarkko Sakkinen
@ 2024-05-19 0:25 ` Jarkko Sakkinen
2024-05-19 12:49 ` [PATCH RFC v2 0/5] Asymmetric TPM2 key type Jarkko Sakkinen
5 siblings, 0 replies; 7+ messages in thread
From: Jarkko Sakkinen @ 2024-05-19 0:25 UTC (permalink / raw)
To: Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, Jarkko Sakkinen, David Howells, David S. Miller,
Peter Huewe, Jason Gunthorpe, James Bottomley, Stefan Berger,
Ard Biesheuvel, Mario Limonciello, open list:CRYPTO API,
open list
From: James Prestwood <prestwoj@gmail.com>
Based on earlier work by James Prestwood.
Add ASN.1 compatible asymmetric TPM2 RSA key subtype:
1. Signing and decryption (with the private key) is handled by TPM2_RSA_Decrypt.
2. Encryption (with the public key) is handled by the kernel RSA
implementation.
Link: https://lore.kernel.org/all/20200518172704.29608-1-prestwoj@gmail.com/
Signed-off-by: James Prestwood <prestwoj@gmail.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
crypto/asymmetric_keys/Kconfig | 13 +
crypto/asymmetric_keys/Makefile | 1 +
crypto/asymmetric_keys/tpm2_key_rsa.c | 655 ++++++++++++++++++++++++++
drivers/char/tpm/Kconfig | 3 -
drivers/char/tpm/tpm2_key.c | 11 +
include/crypto/tpm2_key.h | 3 +
include/linux/tpm.h | 1 +
7 files changed, 684 insertions(+), 3 deletions(-)
create mode 100644 crypto/asymmetric_keys/tpm2_key_rsa.c
diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
index e1345b8f39f1..f83defe562a1 100644
--- a/crypto/asymmetric_keys/Kconfig
+++ b/crypto/asymmetric_keys/Kconfig
@@ -23,6 +23,19 @@ config ASYMMETRIC_PUBLIC_KEY_SUBTYPE
appropriate hash algorithms (such as SHA-1) must be available.
ENOPKG will be reported if the requisite algorithm is unavailable.
+config ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE
+ tristate "Asymmetric TPM2 RSA crypto algorithm subtype"
+ depends on TCG_TPM
+ select TCG_TPM2_HMAC
+ select CRYPTO_RSA
+ select CRYPTO_SHA256
+ select CRYPTO_HASH_INFO
+ help
+ This option provides support for asymmetric TPM2 key type handling.
+ If signature generation and/or verification are to be used,
+ appropriate hash algorithms (such as SHA-256) must be available.
+ ENOPKG will be reported if the requisite algorithm is unavailable.
+
config X509_CERTIFICATE_PARSER
tristate "X.509 certificate parser"
depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
index bc65d3b98dcb..c6da84607824 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -11,6 +11,7 @@ asymmetric_keys-y := \
signature.o
obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
+obj-$(CONFIG_ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE) += tpm2_key_rsa.o
#
# X.509 Certificate handling
diff --git a/crypto/asymmetric_keys/tpm2_key_rsa.c b/crypto/asymmetric_keys/tpm2_key_rsa.c
new file mode 100644
index 000000000000..8032093605e0
--- /dev/null
+++ b/crypto/asymmetric_keys/tpm2_key_rsa.c
@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* TPM2 asymmetric public-key crypto subtype
+ *
+ * See Documentation/crypto/asymmetric-keys.rst
+ *
+ * Copyright (c) 2020 Intel Corporation
+ */
+
+#define pr_fmt(fmt) "tpm2_key: "fmt
+
+#include <asm/unaligned.h>
+#include <crypto/akcipher.h>
+#include <crypto/public_key.h>
+#include <crypto/rsa-pkcs1pad.h>
+#include <crypto/tpm2_key.h>
+#include <keys/asymmetric-parser.h>
+#include <keys/asymmetric-subtype.h>
+#include <keys/trusted-type.h>
+#include <linux/keyctl.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/tpm.h>
+
+/* Room to fit two u32 zeros for algo id and parameters length. */
+#define SETKEY_PARAMS_SIZE (sizeof(u32) * 2)
+
+/*
+ * 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
+ * bit key and e is usually 65537
+ * The encoding overhead is:
+ * - max 4 bytes for SEQUENCE
+ * - max 4 bytes for INTEGER n type/length
+ * - 257 bytes of n
+ * - max 2 bytes for INTEGER e type/length
+ * - 3 bytes of e
+ * - 4+4 of zeros for set_pub_key parameters (SETKEY_PARAMS_SIZE)
+ */
+#define PUB_KEY_BUF_SIZE (4 + 4 + 257 + 2 + 3 + SETKEY_PARAMS_SIZE)
+
+static int tpm2_rsa_decrypt(struct tpm_chip *chip, u32 parent,
+ const unsigned char *keyblob, size_t bloblen,
+ const void *data, size_t len, void *out)
+{
+ unsigned int private_len;
+ unsigned int public_len;
+ unsigned int parsed_len;
+ unsigned int offset = 0;
+ u32 blob_handle = 0;
+ u32 key_handle = 0;
+ struct tpm_buf buf;
+ u16 decrypted_len;
+ u8 *pos;
+ int ret;
+
+ private_len = be16_to_cpup((__be16 *)&keyblob[0]);
+ if (private_len > (bloblen - 2))
+ return -EINVAL;
+
+ public_len = be16_to_cpup((__be16 *)&keyblob[2 + private_len]);
+ parsed_len = private_len + public_len + 4;
+ if (parsed_len > bloblen)
+ return -EINVAL;
+
+ ret = tpm_try_get_ops(chip);
+ if (ret)
+ return ret;
+
+ ret = tpm2_start_auth_session(chip);
+ if (ret)
+ goto err_ops;
+
+ if (parent == TPM2_RH_NULL) {
+ ret = tpm2_load_context(chip, chip->null_key_context, &offset,
+ &key_handle);
+ if (ret) {
+ ret = -EIO;
+ goto err_auth;
+ }
+ } else {
+ key_handle = parent;
+ }
+
+ ret = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
+ if (ret < 0)
+ goto err_key;
+
+ tpm_buf_append_name(chip, &buf, key_handle, NULL);
+ tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_CONTINUE_SESSION |
+ TPM2_SA_ENCRYPT, NULL, 0);
+ tpm_buf_append(&buf, keyblob, bloblen);
+
+ if (buf.flags & TPM_BUF_OVERFLOW) {
+ ret = -E2BIG;
+ goto err_buf;
+ }
+
+ tpm_buf_fill_hmac_session(chip, &buf);
+ ret = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
+ ret = tpm_buf_check_hmac_response(chip, &buf, ret);
+ if (ret) {
+ ret = -EIO;
+ goto err_buf;
+ }
+
+ blob_handle = be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE]);
+
+ tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_RSA_DECRYPT);
+
+ tpm_buf_append_name(chip, &buf, blob_handle, NULL);
+ tpm_buf_append_hmac_session(chip, &buf, TPM2_SA_DECRYPT, NULL, 0);
+
+ tpm_buf_append_u16(&buf, len);
+ tpm_buf_append(&buf, data, len);
+ tpm_buf_append_u16(&buf, TPM_ALG_NULL);
+ tpm_buf_append_u16(&buf, 0);
+
+ tpm_buf_fill_hmac_session(chip, &buf);
+ ret = tpm_transmit_cmd(chip, &buf, 4, "decrypting RSA");
+ ret = tpm_buf_check_hmac_response(chip, &buf, ret);
+ if (ret) {
+ ret = -EIO;
+ goto err_blob;
+ }
+
+ pos = buf.data + TPM_HEADER_SIZE + 4;
+ decrypted_len = be16_to_cpup((__be16 *)pos);
+ pos += 2;
+
+ memcpy(out, pos, decrypted_len);
+ ret = decrypted_len;
+
+err_blob:
+ tpm2_flush_context(chip, blob_handle);
+
+err_buf:
+ tpm_buf_destroy(&buf);
+
+err_key:
+ tpm2_flush_context(chip, key_handle);
+
+err_auth:
+ if (ret < 0)
+ tpm2_end_auth_session(chip);
+
+err_ops:
+ tpm_put_ops(chip);
+ return ret;
+}
+
+/*
+ * PKCS1 padding (type 1)
+ */
+static int tpm2_pad_pkcs1(const u8 *m, unsigned int mlen,
+ u8 *em, unsigned int em_len)
+{
+ unsigned int ps_len = em_len - mlen - 3;
+
+ if (mlen > em_len - 11)
+ return -EBADMSG;
+
+ em[0] = 0;
+ em[1] = 1;
+
+ memset(em + 2, 0xff, ps_len);
+
+ em[2 + ps_len] = 0;
+ memcpy(em + 2 + ps_len + 1, m, mlen);
+
+ return 0;
+}
+
+/*
+ * RFC 3447 - Section 7.2.2
+ */
+static const u8 *tpm2_unpad_pkcs1(const u8 *data, unsigned int len,
+ unsigned int *out_len)
+{
+ unsigned int i;
+
+ /*
+ * Size of input data should be checked against public key size by
+ * caller.
+ */
+ if (data[0] != 0 || data[1] != 2)
+ return NULL;
+
+ i = 2;
+
+ while (data[i] != 0 && i < len)
+ i++;
+
+ if (i == len)
+ return NULL;
+
+ *out_len = len - i - 1;
+
+ return data + i + 1;
+}
+
+/*
+ * Outputs the cipher algorithm name on success, and retuns -ENOPKG
+ * on failure.
+ */
+static int tpm2_key_get_akcipher(const char *encoding, const char *hash_algo,
+ char *cipher)
+{
+ ssize_t ret;
+
+ if (strcmp(encoding, "pkcs1") == 0) {
+ if (!hash_algo) {
+ strcpy(cipher, "pkcs1pad(rsa)");
+ return 0;
+ }
+
+ ret = snprintf(cipher, CRYPTO_MAX_ALG_NAME,
+ "pkcs1pad(rsa,%s)",
+ hash_algo);
+ if (ret >= CRYPTO_MAX_ALG_NAME)
+ return -ENOPKG;
+
+ return 0;
+ }
+
+ if (strcmp(encoding, "raw") == 0) {
+ strcpy(cipher, "rsa");
+ return 0;
+ }
+
+ return -ENOPKG;
+}
+
+static inline u8 *tpm2_key_append_tag(u8 *buf, u8 tag, u32 len)
+{
+ *buf++ = tag;
+
+ if (len <= 127) {
+ buf[0] = len;
+ return buf + 1;
+ }
+
+ if (len <= 255) {
+ buf[0] = 0x81;
+ buf[1] = len;
+ return buf + 2;
+ }
+
+ buf[0] = 0x82;
+ put_unaligned_be16(len, buf + 1);
+ return buf + 3;
+}
+
+static inline u32 tpm2_key_definite_length(u32 len)
+{
+ if (len <= 127)
+ return 1;
+ if (len <= 255)
+ return 2;
+ return 3;
+}
+
+static u32 tpm2_key_to_der(const void *pub_key, u32 len, u8 *buf)
+{
+ u8 *cur = buf;
+ u32 n_len = tpm2_key_definite_length(len) + 1 + len + 1;
+ u32 e_len = tpm2_key_definite_length(3) + 1 + 3;
+ u8 e[3] = { 0x01, 0x00, 0x01 };
+
+ /* SEQUENCE */
+ cur = tpm2_key_append_tag(cur, 0x30, n_len + e_len);
+ /* INTEGER n */
+ cur = tpm2_key_append_tag(cur, 0x02, len + 1);
+ cur[0] = 0x00;
+ memcpy(cur + 1, pub_key, len);
+ cur += len + 1;
+ cur = tpm2_key_append_tag(cur, 0x02, sizeof(e));
+ memcpy(cur, e, sizeof(e));
+ cur += sizeof(e);
+ /* Zero parameters to satisfy set_pub_key ABI. */
+ memset(cur, 0, SETKEY_PARAMS_SIZE);
+
+ return cur - buf;
+}
+
+/*
+ * Encryption operation is performed with the public key. Hence it is done
+ * in software
+ */
+static int tpm2_key_rsa_encrypt(struct tpm2_key *key,
+ struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ char cipher[CRYPTO_MAX_ALG_NAME];
+ struct scatterlist in_sg, out_sg;
+ u8 der_pub_key[PUB_KEY_BUF_SIZE];
+ struct akcipher_request *req;
+ struct crypto_akcipher *tfm;
+ struct crypto_wait cwait;
+ u32 der_pub_key_len;
+ int rc;
+
+ rc = tpm2_key_get_akcipher(params->encoding, params->hash_algo, cipher);
+ if (rc < 0)
+ return rc;
+
+ tfm = crypto_alloc_akcipher(cipher, 0, 0);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ der_pub_key_len = tpm2_key_to_der(key->pub, key->pub_len, der_pub_key);
+
+ rc = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
+ if (rc < 0)
+ goto err_tfm;
+
+ req = akcipher_request_alloc(tfm, GFP_KERNEL);
+ if (!req) {
+ rc = -ENOMEM;
+ goto err_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);
+
+ rc = crypto_akcipher_encrypt(req);
+ rc = crypto_wait_req(rc, &cwait);
+
+ if (!rc)
+ rc = req->dst_len;
+
+ akcipher_request_free(req);
+
+err_tfm:
+ crypto_free_akcipher(tfm);
+
+ return rc;
+}
+
+/*
+ * Decryption operation is performed with the private key in the TPM.
+ */
+static int tpm2_key_rsa_decrypt(struct tpm_chip *chip, struct tpm2_key *key,
+ struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ unsigned int unpadded_len;
+ const u8 *unpadded;
+ u8 *decrypted;
+ int rc;
+
+ decrypted = kmalloc(key->pub_len, GFP_KERNEL);
+
+ rc = tpm2_rsa_decrypt(chip, key->parent, key->blob, key->blob_len, in,
+ params->in_len, decrypted);
+ if (rc < 0)
+ return rc;
+
+ unpadded = tpm2_unpad_pkcs1(decrypted, rc, &unpadded_len);
+ if (!unpadded)
+ return -EINVAL;
+
+ memcpy(out, unpadded, unpadded_len);
+ return unpadded_len;
+}
+
+/*
+ * Sign operation is an encryption using the TPM's private key. With RSA the
+ * only difference between encryption and decryption is where the padding goes.
+ * Since own padding can be used, TPM2_RSA_Decrypt can be repurposed to do
+ * encryption.
+ */
+static int tpm2_key_rsa_sign(struct tpm_chip *chip, struct tpm2_key *key,
+ struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ const struct rsa_asn1_template *asn1;
+ u32 in_len = params->in_len;
+ void *asn1_wrapped = NULL;
+ u8 *padded;
+ int rc;
+
+ if (strcmp(params->encoding, "pkcs1")) {
+ rc = -ENOPKG;
+ goto done;
+ }
+
+ if (params->hash_algo) {
+ asn1 = rsa_lookup_asn1(params->hash_algo);
+ if (!asn1) {
+ rc = -ENOPKG;
+ goto done;
+ }
+
+ /* Request enough space for the ASN.1 template + input hash */
+ asn1_wrapped = kzalloc(in_len + asn1->size, GFP_KERNEL);
+ if (!asn1_wrapped) {
+ rc = -ENOMEM;
+ goto done;
+ }
+
+ /* 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;
+ }
+
+ /*
+ * Using the TPM's decrypt call to sign (aka encrypt). This
+ * requires pre-padding the data with PKCS1.
+ */
+ padded = kmalloc(key->pub_len, GFP_KERNEL);
+ tpm2_pad_pkcs1(in, in_len, padded, key->pub_len);
+
+ rc = tpm2_rsa_decrypt(chip, key->parent, key->blob, key->blob_len,
+ padded, key->pub_len, out);
+
+ kfree(padded);
+done:
+ kfree(asn1_wrapped);
+ return rc;
+}
+
+static void tpm2_key_rsa_describe(const struct key *asymmetric_key,
+ struct seq_file *m)
+{
+ struct tpm2_key *key = asymmetric_key->payload.data[asym_crypto];
+
+ if (!key) {
+ pr_err("key is empty");
+ return;
+ }
+
+ seq_puts(m, "TPM2/RSA");
+}
+
+static void tpm2_key_rsa_destroy(void *payload0, void *payload3)
+{
+ struct tpm2_key *key = payload0;
+
+ if (!key)
+ return;
+
+ tpm2_key_destroy(key);
+}
+
+static int tpm2_key_rsa_eds_op(struct kernel_pkey_params *params,
+ const void *in, void *out)
+{
+ struct tpm2_key *key = params->key->payload.data[asym_crypto];
+ struct tpm_chip *chip = tpm_default_chip();
+ int rc = -EOPNOTSUPP;
+
+ if (!chip)
+ return -ENODEV;
+
+ switch (params->op) {
+ case kernel_pkey_encrypt:
+ rc = tpm2_key_rsa_encrypt(key, params, in, out);
+ break;
+ case kernel_pkey_decrypt:
+ rc = tpm2_key_rsa_decrypt(chip, key, params, in, out);
+ break;
+ case kernel_pkey_sign:
+ rc = tpm2_key_rsa_sign(chip, key, params, in, out);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return rc;
+}
+
+static int tpm2_key_rsa_verify(const struct key *key,
+ const struct public_key_signature *sig)
+{
+ const struct tpm2_key *tk = key->payload.data[asym_crypto];
+ char alg_name[CRYPTO_MAX_ALG_NAME];
+ u8 der_pub_key[PUB_KEY_BUF_SIZE];
+ struct akcipher_request *req;
+ struct scatterlist src_sg[2];
+ struct crypto_akcipher *tfm;
+ struct crypto_wait cwait;
+ u32 der_pub_key_len;
+ int rc;
+
+ if (WARN_ON(!tk || !sig || !sig->s))
+ return -EINVAL;
+
+ if (!sig->digest)
+ return -ENOPKG;
+
+ rc = tpm2_key_get_akcipher(sig->encoding, sig->hash_algo, alg_name);
+ if (rc < 0)
+ return rc;
+
+ tfm = crypto_alloc_akcipher(alg_name, 0, 0);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ der_pub_key_len = tpm2_key_to_der(tk->pub, tk->pub_len, der_pub_key);
+
+ rc = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
+ if (rc < 0)
+ goto err_tfm;
+
+ rc = -ENOMEM;
+ req = akcipher_request_alloc(tfm, GFP_KERNEL);
+ if (!req)
+ goto err_tfm;
+
+ sg_init_table(src_sg, 2);
+ sg_set_buf(&src_sg[0], sig->s, sig->s_size);
+ sg_set_buf(&src_sg[1], sig->digest, sig->digest_size);
+ akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size,
+ sig->digest_size);
+ crypto_init_wait(&cwait);
+ akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+ CRYPTO_TFM_REQ_MAY_SLEEP,
+ crypto_req_done, &cwait);
+ rc = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
+
+ akcipher_request_free(req);
+err_tfm:
+ crypto_free_akcipher(tfm);
+ pr_devel("<=%s() = %d\n", __func__, rc);
+ if (WARN_ON_ONCE(rc > 0))
+ rc = -EINVAL;
+ return rc;
+}
+
+static int tpm2_key_rsa_query(const struct kernel_pkey_params *params,
+ struct kernel_pkey_query *info)
+{
+ struct tpm2_key *tk = params->key->payload.data[asym_crypto];
+ char alg_name[CRYPTO_MAX_ALG_NAME];
+ u8 der_pub_key[PUB_KEY_BUF_SIZE];
+ struct crypto_akcipher *tfm;
+ u32 der_pub_key_len = 0;
+ unsigned int len;
+ int ret;
+
+ ret = tpm2_key_get_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 = tpm2_key_to_der(tk->pub, tk->pub_len, der_pub_key);
+
+ ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
+ if (ret < 0)
+ goto err_tfm;
+
+ len = crypto_akcipher_maxsize(tfm);
+
+ info->key_size = tk->pub_len * 8;
+ info->max_data_size = tk->pub_len;
+ info->max_sig_size = len;
+ info->max_enc_size = len;
+ info->max_dec_size = tk->pub_len;
+
+ info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT |
+ KEYCTL_SUPPORTS_DECRYPT |
+ KEYCTL_SUPPORTS_VERIFY |
+ KEYCTL_SUPPORTS_SIGN;
+
+err_tfm:
+ crypto_free_akcipher(tfm);
+ return ret;
+}
+
+/*
+ * Asymmetric TPM2 RSA key. Signs and decrypts with TPM.
+ */
+struct asymmetric_key_subtype tpm2_key_rsa_subtype = {
+ .owner = THIS_MODULE,
+ .name = "tpm2_key_rsa",
+ .name_len = sizeof("tpm2_key_rsa") - 1,
+ .describe = tpm2_key_rsa_describe,
+ .destroy = tpm2_key_rsa_destroy,
+ .query = tpm2_key_rsa_query,
+ .eds_op = tpm2_key_rsa_eds_op,
+ .verify_signature = tpm2_key_rsa_verify,
+};
+EXPORT_SYMBOL_GPL(tpm2_key_rsa_subtype);
+
+/*
+ * Attempt to parse a data blob for a key as a TPM private key blob.
+ */
+static int tpm2_key_preparse(struct key_preparsed_payload *prep)
+{
+ struct tpm2_key *key;
+ int ret;
+
+ key = kzalloc(sizeof(*key), GFP_KERNEL);
+ if (!key)
+ return -ENOMEM;
+
+ /*
+ * TPM 2.0 RSA keys are recommended to be 2048 bits long. Assume the
+ * blob is no more than 4x that.
+ */
+ if (prep->datalen > 256 * 4) {
+ kfree(key);
+ return -EMSGSIZE;
+ }
+
+ ret = tpm2_key_decode(prep->data, prep->datalen, key, MAX_BLOB_SIZE);
+ if (ret) {
+ kfree(key);
+ return ret;
+ }
+
+ prep->payload.data[asym_subtype] = &tpm2_key_rsa_subtype;
+ prep->payload.data[asym_key_ids] = NULL;
+ prep->payload.data[asym_crypto] = key;
+ prep->payload.data[asym_auth] = NULL;
+ prep->quotalen = 100;
+
+ return 0;
+}
+
+static struct asymmetric_key_parser tpm2_key_rsa_parser = {
+ .owner = THIS_MODULE,
+ .name = "tpm2_key_rsa_parser",
+ .parse = tpm2_key_preparse,
+};
+
+static int __init tpm2_key_rsa_init(void)
+{
+ return register_asymmetric_key_parser(&tpm2_key_rsa_parser);
+}
+
+static void __exit tpm2_key_rsa_exit(void)
+{
+ unregister_asymmetric_key_parser(&tpm2_key_rsa_parser);
+}
+
+module_init(tpm2_key_rsa_init);
+module_exit(tpm2_key_rsa_exit);
+
+MODULE_DESCRIPTION("Asymmetric TPM2 RSA key");
+MODULE_LICENSE("GPL");
diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index d5d06cc96932..d0f71f51f2ae 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -3,9 +3,6 @@
# TPM device configuration
#
-config TCG_TPM2_KEY
- bool
-
menuconfig TCG_TPM
tristate "TPM Hardware Support"
depends on HAS_IOMEM
diff --git a/drivers/char/tpm/tpm2_key.c b/drivers/char/tpm/tpm2_key.c
index e09441efb0f0..0d125b53de0e 100644
--- a/drivers/char/tpm/tpm2_key.c
+++ b/drivers/char/tpm/tpm2_key.c
@@ -175,6 +175,17 @@ int tpm2_key_decode(const u8 *src, u32 src_len, struct tpm2_key *key,
return -ENOMEM;
}
+ ctx.blob_len = ctx.priv_len + ctx.pub_len;
+ ctx.blob = kmalloc(ctx.priv_len + ctx.pub_len, GFP_KERNEL);
+ if (!ctx.blob) {
+ kfree(ctx.pub);
+ kfree(ctx.priv);
+ return -ENOMEM;
+ }
+
+ memcpy((void *)ctx.blob, ctx.priv, ctx.priv_len);
+ memcpy((void *)ctx.blob + ctx.priv_len, ctx.pub, ctx.pub_len);
+
memcpy(key, &ctx, sizeof(ctx));
return 0;
}
diff --git a/include/crypto/tpm2_key.h b/include/crypto/tpm2_key.h
index e5d3330afef5..7b5c5ec6bed5 100644
--- a/include/crypto/tpm2_key.h
+++ b/include/crypto/tpm2_key.h
@@ -13,6 +13,8 @@ struct tpm2_key {
u32 pub_len;
const u8 *priv;
u32 priv_len;
+ const u8 *blob;
+ u32 blob_len;
};
int tpm2_key_encode(u8 *blob, u32 blob_auth_len, u32 key_handle, u8 *src);
@@ -27,6 +29,7 @@ static inline void tpm2_key_destroy(struct tpm2_key *key)
{
kfree(key->priv);
kfree(key->pub);
+ kfree(key->blob);
memset(key, 0, sizeof(*key));
}
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 2f25ca07127b..238814ee5c6f 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -271,6 +271,7 @@ enum tpm2_command_codes {
TPM2_CC_NV_READ = 0x014E,
TPM2_CC_CREATE = 0x0153,
TPM2_CC_LOAD = 0x0157,
+ TPM2_CC_RSA_DECRYPT = 0x0159,
TPM2_CC_SEQUENCE_UPDATE = 0x015C,
TPM2_CC_UNSEAL = 0x015E,
TPM2_CC_CONTEXT_LOAD = 0x0161,
--
2.45.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH RFC v2 0/5] Asymmetric TPM2 key type
2024-05-19 0:25 [PATCH RFC v2 0/5] Asymmetric TPM2 key type Jarkko Sakkinen
` (4 preceding siblings ...)
2024-05-19 0:25 ` [PATCH RFC v2 5/5] keys: asymmetric: ASYMMETRIC_TPM2_KEY_RSA_SUBTYPE Jarkko Sakkinen
@ 2024-05-19 12:49 ` Jarkko Sakkinen
5 siblings, 0 replies; 7+ messages in thread
From: Jarkko Sakkinen @ 2024-05-19 12:49 UTC (permalink / raw)
To: Jarkko Sakkinen, Herbert Xu
Cc: linux-integrity, keyrings, Andreas.Fuchs, James Prestwood,
David Woodhouse, David Howells, David S. Miller, Peter Huewe,
Jason Gunthorpe, James Bottomley, Stefan Berger, Ard Biesheuvel,
Mario Limonciello, open list:CRYPTO API, open list
On Sun May 19, 2024 at 3:25 AM EEST, Jarkko Sakkinen wrote:
> ## Overview
>
> Introduce tpm2_key_rsa implementing asymmetric TPM RSA key.
>
> I submit this first as RFC as I could not execute the keyctl padd in the
> following sequence (returns EBADF):
>
> tpm2_createprimary --hierarchy o -G rsa2048 -c owner.txt
> tpm2_evictcontrol -c owner.txt 0x81000001
> tpm2_getcap handles-persistent
> openssl genrsa -out private.pem 2048
> tpm2_import -C 0x81000001 -G rsa -i private.pem -u key.pub -r key.priv
> tpm2_encodeobject -C 0x81000001 -u key.pub -r key.priv -o key.priv.pem
> openssl asn1parse -inform pem -in key.priv.pem -noout -out key.priv.der
> key_serial=`cat key.priv.der | keyctl padd asymmetric tpm @u`
After v2 changes it ends up to -EINVAL and:
OID is "2.23.133.10.1.3" which is not TPMSealedData
which makes total sense. James' old patch set has already TPMLoadableKey
parsing PoC'd so I use that as the reference.
After the sequence above successfully completes keyctl public key ops
are accesible by using $key_serial as the serial.
BR, Jarkko
^ permalink raw reply [flat|nested] 7+ messages in thread