systemd/SOURCES/0612-tpm2-add-tpm2_marshal_blob-and-tpm2_unmarshal_blob.patch

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2024-04-30 11:42:21 +00:00
From 10ea7ea6b2fbbb3b1b98b563fa6d7804ac9f33ec Mon Sep 17 00:00:00 2001
From: Dan Streetman <ddstreet@ieee.org>
Date: Wed, 28 Jun 2023 11:46:31 -0400
Subject: [PATCH] tpm2: add tpm2_marshal_blob() and tpm2_unmarshal_blob()
Add functions to marshal and unmarshal our 'blob' object.
(cherry picked from commit 653c3fe9085fca81f0533bb8ee53ef5547ed513e)
Related: RHEL-16182
---
src/shared/tpm2-util.c | 113 ++++++++++++++++++++++++++++++-----------
src/shared/tpm2-util.h | 3 ++
2 files changed, 85 insertions(+), 31 deletions(-)
diff --git a/src/shared/tpm2-util.c b/src/shared/tpm2-util.c
index 05189d9dfe..afa3db9c07 100644
--- a/src/shared/tpm2-util.c
+++ b/src/shared/tpm2-util.c
@@ -3688,6 +3688,79 @@ int tpm2_tpm2b_public_from_pem(const void *pem, size_t pem_size, TPM2B_PUBLIC *r
#endif
}
+/* Marshal the public and private objects into a single nonstandard 'blob'. This is not a (publicly) standard
+ * format, this is specific to how we currently store the sealed object. This 'blob' can be unmarshalled by
+ * tpm2_unmarshal_blob(). */
+int tpm2_marshal_blob(
+ const TPM2B_PUBLIC *public,
+ const TPM2B_PRIVATE *private,
+ void **ret_blob,
+ size_t *ret_blob_size) {
+
+ TSS2_RC rc;
+
+ assert(public);
+ assert(private);
+ assert(ret_blob);
+ assert(ret_blob_size);
+
+ size_t max_size = sizeof(*private) + sizeof(*public);
+
+ _cleanup_free_ void *blob = malloc(max_size);
+ if (!blob)
+ return log_oom_debug();
+
+ size_t blob_size = 0;
+ rc = sym_Tss2_MU_TPM2B_PRIVATE_Marshal(private, blob, max_size, &blob_size);
+ if (rc != TSS2_RC_SUCCESS)
+ return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
+ "Failed to marshal private key: %s", sym_Tss2_RC_Decode(rc));
+
+ rc = sym_Tss2_MU_TPM2B_PUBLIC_Marshal(public, blob, max_size, &blob_size);
+ if (rc != TSS2_RC_SUCCESS)
+ return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
+ "Failed to marshal public key: %s", sym_Tss2_RC_Decode(rc));
+
+ *ret_blob = TAKE_PTR(blob);
+ *ret_blob_size = blob_size;
+
+ return 0;
+}
+
+/* Unmarshal the 'blob' into public and private objects. This is not a (publicly) standard format, this is
+ * specific to how we currently store the sealed object. This expects the 'blob' to have been created by
+ * tpm2_marshal_blob(). */
+int tpm2_unmarshal_blob(
+ const void *blob,
+ size_t blob_size,
+ TPM2B_PUBLIC *ret_public,
+ TPM2B_PRIVATE *ret_private) {
+
+ TSS2_RC rc;
+
+ assert(blob);
+ assert(ret_public);
+ assert(ret_private);
+
+ TPM2B_PRIVATE private = {};
+ size_t offset = 0;
+ rc = sym_Tss2_MU_TPM2B_PRIVATE_Unmarshal(blob, blob_size, &offset, &private);
+ if (rc != TSS2_RC_SUCCESS)
+ return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
+ "Failed to unmarshal private key: %s", sym_Tss2_RC_Decode(rc));
+
+ TPM2B_PUBLIC public = {};
+ rc = sym_Tss2_MU_TPM2B_PUBLIC_Unmarshal(blob, blob_size, &offset, &public);
+ if (rc != TSS2_RC_SUCCESS)
+ return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
+ "Failed to unmarshal public key: %s", sym_Tss2_RC_Decode(rc));
+
+ *ret_public = public;
+ *ret_private = private;
+
+ return 0;
+}
+
int tpm2_seal(Tpm2Context *c,
const TPM2B_DIGEST *policy,
const char *pin,
@@ -3825,21 +3898,10 @@ int tpm2_seal(Tpm2Context *c,
log_debug("Marshalling private and public part of HMAC key.");
_cleanup_free_ void *blob = NULL;
- size_t max_size = sizeof(*private) + sizeof(*public), blob_size = 0;
-
- blob = malloc0(max_size);
- if (!blob)
- return log_oom();
-
- rc = sym_Tss2_MU_TPM2B_PRIVATE_Marshal(private, blob, max_size, &blob_size);
- if (rc != TSS2_RC_SUCCESS)
- return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "Failed to marshal private key: %s", sym_Tss2_RC_Decode(rc));
-
- rc = sym_Tss2_MU_TPM2B_PUBLIC_Marshal(public, blob, max_size, &blob_size);
- if (rc != TSS2_RC_SUCCESS)
- return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "Failed to marshal public key: %s", sym_Tss2_RC_Decode(rc));
+ size_t blob_size;
+ r = tpm2_marshal_blob(public, private, &blob, &blob_size);
+ if (r < 0)
+ return log_error_errno(r, "Could not create sealed blob: %m");
/* serialize the key for storage in the LUKS header. A deserialized ESYS_TR provides both
* the raw TPM handle as well as the object name. The object name is used to verify that
@@ -3930,22 +3992,11 @@ int tpm2_unseal(const char *device,
usec_t start = now(CLOCK_MONOTONIC);
- log_debug("Unmarshalling private part of HMAC key.");
-
- TPM2B_PRIVATE private = {};
- size_t offset = 0;
- rc = sym_Tss2_MU_TPM2B_PRIVATE_Unmarshal(blob, blob_size, &offset, &private);
- if (rc != TSS2_RC_SUCCESS)
- return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "Failed to unmarshal private key: %s", sym_Tss2_RC_Decode(rc));
-
- log_debug("Unmarshalling public part of HMAC key.");
-
- TPM2B_PUBLIC public = {};
- rc = sym_Tss2_MU_TPM2B_PUBLIC_Unmarshal(blob, blob_size, &offset, &public);
- if (rc != TSS2_RC_SUCCESS)
- return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "Failed to unmarshal public key: %s", sym_Tss2_RC_Decode(rc));
+ TPM2B_PUBLIC public;
+ TPM2B_PRIVATE private;
+ r = tpm2_unmarshal_blob(blob, blob_size, &public, &private);
+ if (r < 0)
+ return log_error_errno(r, "Could not extract parts from blob: %m");
_cleanup_(tpm2_context_unrefp) Tpm2Context *c = NULL;
r = tpm2_context_new(device, &c);
diff --git a/src/shared/tpm2-util.h b/src/shared/tpm2-util.h
index f9efca9311..7b0750b03a 100644
--- a/src/shared/tpm2-util.h
+++ b/src/shared/tpm2-util.h
@@ -164,6 +164,9 @@ int tpm2_calculate_policy_authorize(const TPM2B_PUBLIC *public, const TPM2B_DIGE
int tpm2_calculate_policy_pcr(const Tpm2PCRValue *pcr_values, size_t n_pcr_values, TPM2B_DIGEST *digest);
int tpm2_calculate_sealing_policy(const Tpm2PCRValue *pcr_values, size_t n_pcr_values, const TPM2B_PUBLIC *public, bool use_pin, TPM2B_DIGEST *digest);
+int tpm2_marshal_blob(const TPM2B_PUBLIC *public, const TPM2B_PRIVATE *private, void **ret_blob, size_t *ret_blob_size);
+int tpm2_unmarshal_blob(const void *blob, size_t blob_size, TPM2B_PUBLIC *ret_public, TPM2B_PRIVATE *ret_private);
+
int tpm2_seal(Tpm2Context *c, const TPM2B_DIGEST *policy, const char *pin, void **ret_secret, size_t *ret_secret_size, void **ret_blob, size_t *ret_blob_size, uint16_t *ret_primary_alg, void **ret_srk_buf, size_t *ret_srk_buf_size);
int tpm2_unseal(const char *device, uint32_t hash_pcr_mask, uint16_t pcr_bank, const void *pubkey, size_t pubkey_size, uint32_t pubkey_pcr_mask, JsonVariant *signature, const char *pin, uint16_t primary_alg, const void *blob, size_t blob_size, const void *policy_hash, size_t policy_hash_size, const void *srk_buf, size_t srk_buf_size, void **ret_secret, size_t *ret_secret_size);