1 files changed, 109 insertions, 0 deletions
diff --git a/src/cryptsetup/cryptsetup-tokens/luks2-tpm2.c b/src/cryptsetup/cryptsetup-tokens/luks2-tpm2.c
new file mode 100644
index 0000000..72be5cc
--- /dev/null
+++ b/src/cryptsetup/cryptsetup-tokens/luks2-tpm2.c
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "alloc-util.h"
+#include "ask-password-api.h"
+#include "env-util.h"
+#include "hexdecoct.h"
+#include "json.h"
+#include "log.h"
+#include "luks2-tpm2.h"
+#include "parse-util.h"
+#include "random-util.h"
+#include "sha256.h"
+#include "strv.h"
+#include "tpm2-util.h"
+
+int acquire_luks2_key(
+                const char *device,
+                uint32_t hash_pcr_mask,
+                uint16_t pcr_bank,
+                const void *pubkey,
+                size_t pubkey_size,
+                uint32_t pubkey_pcr_mask,
+                const char *signature_path,
+                const char *pin,
+                const char *pcrlock_path,
+                uint16_t primary_alg,
+                const void *key_data,
+                size_t key_data_size,
+                const void *policy_hash,
+                size_t policy_hash_size,
+                const void *salt,
+                size_t salt_size,
+                const void *srk_buf,
+                size_t srk_buf_size,
+                TPM2Flags flags,
+                void **ret_decrypted_key,
+                size_t *ret_decrypted_key_size) {
+
+        _cleanup_(json_variant_unrefp) JsonVariant *signature_json = NULL;
+        _cleanup_free_ char *auto_device = NULL;
+        _cleanup_(erase_and_freep) char *b64_salted_pin = NULL;
+        int r;
+
+        assert(salt || salt_size == 0);
+        assert(ret_decrypted_key);
+        assert(ret_decrypted_key_size);
+
+        if (!device) {
+                r = tpm2_find_device_auto(&auto_device);
+                if (r == -ENODEV)
+                        return -EAGAIN; /* Tell the caller to wait for a TPM2 device to show up */
+                if (r < 0)
+                        return log_error_errno(r, "Could not find TPM2 device: %m");
+
+                device = auto_device;
+        }
+
+        if ((flags & TPM2_FLAGS_USE_PIN) && !pin)
+                return -ENOANO;
+
+        if (pin && salt_size > 0) {
+                uint8_t salted_pin[SHA256_DIGEST_SIZE] = {};
+                CLEANUP_ERASE(salted_pin);
+                r = tpm2_util_pbkdf2_hmac_sha256(pin, strlen(pin), salt, salt_size, salted_pin);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to perform PBKDF2: %m");
+
+                r = base64mem(salted_pin, sizeof(salted_pin), &b64_salted_pin);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to base64 encode salted pin: %m");
+                pin = b64_salted_pin;
+        }
+
+        if (pubkey_pcr_mask != 0) {
+                r = tpm2_load_pcr_signature(signature_path, &signature_json);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to load PCR signature: %m");
+        }
+
+        _cleanup_(tpm2_pcrlock_policy_done) Tpm2PCRLockPolicy pcrlock_policy = {};
+        if (FLAGS_SET(flags, TPM2_FLAGS_USE_PCRLOCK)) {
+                r = tpm2_pcrlock_policy_load(pcrlock_path, &pcrlock_policy);
+                if (r < 0)
+                        return r;
+        }
+
+        _cleanup_(tpm2_context_unrefp) Tpm2Context *tpm2_context = NULL;
+        r = tpm2_context_new(device, &tpm2_context);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create TPM2 context: %m");
+
+        r = tpm2_unseal(tpm2_context,
+                        hash_pcr_mask,
+                        pcr_bank,
+                        pubkey, pubkey_size,
+                        pubkey_pcr_mask,
+                        signature_json,
+                        pin,
+                        FLAGS_SET(flags, TPM2_FLAGS_USE_PCRLOCK) ? &pcrlock_policy : NULL,
+                        primary_alg,
+                        key_data, key_data_size,
+                        policy_hash, policy_hash_size,
+                        srk_buf, srk_buf_size,
+                        ret_decrypted_key, ret_decrypted_key_size);
+        if (r < 0)
+                return log_error_errno(r, "Failed to unseal secret using TPM2: %m");
+
+        return r;
+}