systemd/SOURCES/0636-tpm2-allow-using-tpm2_get_srk_template-without-tpm.patch

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2024-04-30 11:42:21 +00:00
From 67238a5417fb32649b83f2da65356908abbcd821 Mon Sep 17 00:00:00 2001
From: Dan Streetman <ddstreet@ieee.org>
Date: Tue, 3 Oct 2023 10:25:19 -0400
Subject: [PATCH] tpm2: allow using tpm2_get_srk_template() without tpm
The SRK templates are defined by specification, so move the check for TPM
support to the tpm2_get_best_srk_template() function, and allow anyone to get
the ECC and RSA templates.
Also add test to verify the SRK templates are correct.
(cherry picked from commit 788933379d9ab219ba085021d0d19ac5d0372cea)
Related: RHEL-16182
---
src/shared/tpm2-util.c | 69 +++++++++++++++++++++++-------------------
src/shared/tpm2-util.h | 2 ++
src/test/test-tpm2.c | 25 +++++++++++++++
3 files changed, 65 insertions(+), 31 deletions(-)
diff --git a/src/shared/tpm2-util.c b/src/shared/tpm2-util.c
index a16e611f27..1751c82450 100644
--- a/src/shared/tpm2-util.c
+++ b/src/shared/tpm2-util.c
@@ -1110,9 +1110,8 @@ static int tpm2_get_legacy_template(TPMI_ALG_PUBLIC alg, TPMT_PUBLIC *ret_templa
* SRK-compatible). Preferably, the TPM should contain a shared SRK located at the reserved shared SRK handle
* (see TPM2_SRK_HANDLE in tpm2-util.h, and tpm2_get_srk() below).
*
- * The alg must be TPM2_ALG_RSA or TPM2_ALG_ECC. Returns error if the requested template is not supported on
- * this TPM. Also see tpm2_get_best_srk_template() below. */
-static int tpm2_get_srk_template(Tpm2Context *c, TPMI_ALG_PUBLIC alg, TPMT_PUBLIC *ret_template) {
+ * Returns 0 if the specified algorithm is ECC or RSA, otherwise -EOPNOTSUPP. */
+int tpm2_get_srk_template(TPMI_ALG_PUBLIC alg, TPMT_PUBLIC *ret_template) {
/* The attributes are the same between ECC and RSA templates. This has the changes specified in the
* Provisioning Guidance document, specifically:
* TPMA_OBJECT_USERWITHAUTH is added.
@@ -1161,47 +1160,55 @@ static int tpm2_get_srk_template(Tpm2Context *c, TPMI_ALG_PUBLIC alg, TPMT_PUBLI
},
};
- assert(c);
assert(ret_template);
- if (alg == TPM2_ALG_ECC) {
- if (!tpm2_supports_alg(c, TPM2_ALG_ECC))
- return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "TPM does not support ECC.");
-
- if (!tpm2_supports_ecc_curve(c, srk_ecc.parameters.eccDetail.curveID))
- return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "TPM does not support ECC-NIST-P256 curve.");
-
- if (!tpm2_supports_tpmt_public(c, &srk_ecc))
- return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "TPM does not support SRK ECC template L-2.");
-
+ switch (alg) {
+ case TPM2_ALG_ECC:
*ret_template = srk_ecc;
return 0;
- }
-
- if (alg == TPM2_ALG_RSA) {
- if (!tpm2_supports_alg(c, TPM2_ALG_RSA))
- return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "TPM does not support RSA.");
-
- if (!tpm2_supports_tpmt_public(c, &srk_rsa))
- return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
- "TPM does not support SRK RSA template L-1.");
-
+ case TPM2_ALG_RSA:
*ret_template = srk_rsa;
return 0;
}
- return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Unsupported SRK alg: 0x%x.", alg);
+ return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "No SRK for algorithm 0x%" PRIx16, alg);
}
/* Get the best supported SRK template. ECC is preferred, then RSA. */
static int tpm2_get_best_srk_template(Tpm2Context *c, TPMT_PUBLIC *ret_template) {
- if (tpm2_get_srk_template(c, TPM2_ALG_ECC, ret_template) >= 0 ||
- tpm2_get_srk_template(c, TPM2_ALG_RSA, ret_template) >= 0)
+ TPMT_PUBLIC template;
+ int r;
+
+ assert(c);
+ assert(ret_template);
+
+ r = tpm2_get_srk_template(TPM2_ALG_ECC, &template);
+ if (r < 0)
+ return r;
+
+ if (!tpm2_supports_alg(c, TPM2_ALG_ECC))
+ log_debug("TPM does not support ECC.");
+ else if (!tpm2_supports_ecc_curve(c, template.parameters.eccDetail.curveID))
+ log_debug("TPM does not support ECC-NIST-P256 curve.");
+ else if (!tpm2_supports_tpmt_public(c, &template))
+ log_debug("TPM does not support SRK ECC template L-2.");
+ else {
+ *ret_template = template;
return 0;
+ }
+
+ r = tpm2_get_srk_template(TPM2_ALG_RSA, &template);
+ if (r < 0)
+ return r;
+
+ if (!tpm2_supports_alg(c, TPM2_ALG_RSA))
+ log_debug("TPM does not support RSA.");
+ else if (!tpm2_supports_tpmt_public(c, &template))
+ log_debug("TPM does not support SRK RSA template L-1.");
+ else {
+ *ret_template = template;
+ return 0;
+ }
return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
"TPM does not support either SRK template L-1 (RSA) or L-2 (ECC).");
diff --git a/src/shared/tpm2-util.h b/src/shared/tpm2-util.h
index c980567819..fe26b98e76 100644
--- a/src/shared/tpm2-util.h
+++ b/src/shared/tpm2-util.h
@@ -181,6 +181,8 @@ 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_get_srk_template(TPMI_ALG_PUBLIC alg, TPMT_PUBLIC *ret_template);
+
int tpm2_get_or_create_srk(Tpm2Context *c, const Tpm2Handle *session, TPM2B_PUBLIC **ret_public, TPM2B_NAME **ret_name, TPM2B_NAME **ret_qname, Tpm2Handle **ret_handle);
int tpm2_seal(Tpm2Context *c, uint32_t seal_key_handle, 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);
diff --git a/src/test/test-tpm2.c b/src/test/test-tpm2.c
index 3df6258934..8a27ffc7db 100644
--- a/src/test/test-tpm2.c
+++ b/src/test/test-tpm2.c
@@ -960,6 +960,31 @@ TEST(calculate_policy_pcr) {
assert_se(digest_check(&d, "7481fd1b116078eb3ac2456e4ad542c9b46b9b8eb891335771ca8e7c8f8e4415"));
}
+TEST(tpm2_get_srk_template) {
+ TPMT_PUBLIC rsa;
+ assert_se(tpm2_get_srk_template(TPM2_ALG_RSA, &rsa) >= 0);
+ assert_se(rsa.type == TPM2_ALG_RSA);
+ assert_se(rsa.nameAlg == TPM2_ALG_SHA256);
+ assert_se(rsa.objectAttributes == 0x30472);
+ assert_se(rsa.parameters.rsaDetail.symmetric.algorithm == TPM2_ALG_AES);
+ assert_se(rsa.parameters.rsaDetail.symmetric.keyBits.sym == 128);
+ assert_se(rsa.parameters.rsaDetail.symmetric.mode.sym == TPM2_ALG_CFB);
+ assert_se(rsa.parameters.rsaDetail.scheme.scheme == TPM2_ALG_NULL);
+ assert_se(rsa.parameters.rsaDetail.keyBits == 2048);
+
+ TPMT_PUBLIC ecc;
+ assert_se(tpm2_get_srk_template(TPM2_ALG_ECC, &ecc) >= 0);
+ assert_se(ecc.type == TPM2_ALG_ECC);
+ assert_se(ecc.nameAlg == TPM2_ALG_SHA256);
+ assert_se(ecc.objectAttributes == 0x30472);
+ assert_se(ecc.parameters.eccDetail.symmetric.algorithm == TPM2_ALG_AES);
+ assert_se(ecc.parameters.eccDetail.symmetric.keyBits.sym == 128);
+ assert_se(ecc.parameters.eccDetail.symmetric.mode.sym == TPM2_ALG_CFB);
+ assert_se(ecc.parameters.eccDetail.scheme.scheme == TPM2_ALG_NULL);
+ assert_se(ecc.parameters.eccDetail.kdf.scheme == TPM2_ALG_NULL);
+ assert_se(ecc.parameters.eccDetail.curveID == TPM2_ECC_NIST_P256);
+}
+
static void check_test_parms(Tpm2Context *c) {
assert(c);