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swtpm_setup: Create IAK and IDevID keys and certificates
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Extend swtpm_setup to create IAK and IDevID keys and certificates.

Use the same CA for signing the IAK and IDevID certificates as used for
the EK and platform certificates since all these certificates are issued
at the same time anyway.

Add documentation to the man page.

Signed-off-by: Stefan Berger <[email protected]>
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@stefanberger
stefanberger committed Oct 31, 2024
1 parent 25450f5 commit 969f50f
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13 changes: 12 additions & 1 deletion man/man8/swtpm_setup.pod
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Original file line number Diff line number Diff line change
Expand Up @@ -291,7 +291,8 @@ The output may contain the following:
"tpm2-rsa-keysize-2048",
"tpm2-rsa-keysize-3072",
"cmdarg-profile",
"cmdarg-profile-remove-disabled"
"cmdarg-profile-remove-disabled",
"cmdarg-no-iak"
],
"version": "0.7.0"
}
Expand Down Expand Up @@ -323,6 +324,12 @@ The I<--create-config-files> option is supported.
The I<--reconfigure> option is supported and allows the reconfiguration of
the active PCR banks.

=item B<cmdarg-no-iak> (since v0.9)

If I<--create-ek-cert> is given then swtpm_setup also creates IAK and IDevID
keys and certificates. When I<--no-iak> is passed then neither one of them is
created.

=item B<tpm2-rsa-keysize-2048, ...> (since v0.4)

The shown RSA key sizes are supported for a TPM 2's EK key. If none of the
Expand Down Expand Up @@ -401,6 +408,10 @@ systems this may be the case when a user is part of the 'tss' group. In
this case it is recommended that the user replace the swtpm-localca.conf
created with this command with a symbolic link to /etc/swtpm-localca.conf.

=item <--no-iak> (since v0.9)

Do not create IAK and IDevID keys and certificates.

=item B<--help, -h>

Display the help screen
Expand Down
160 changes: 160 additions & 0 deletions src/swtpm_setup/swtpm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -418,6 +418,7 @@ static const struct swtpm_cops swtpm_cops = {
#define TPM2_ALG_SHA3_512 0x0029
#define TPM2_ALG_NULL 0x0010
#define TPM2_ALG_SM3 0x0012
#define TPM2_ALG_ECDSA 0x0018
#define TPM2_ALG_ECC 0x0023
#define TPM2_ALG_CFB 0x0043

Expand Down Expand Up @@ -447,6 +448,9 @@ static const struct swtpm_cops swtpm_cops = {
#define TPM2_NV_INDEX_ECC_SECP384R1_HI_EKCERT 0x01c00016
#define TPM2_NV_INDEX_ECC_SECP384R1_HI_EKTEMPLATE 0x01c00017

#define TPM2_NV_INDEX_IDEVID_SHA384 0x01c90011
#define TPM2_NV_INDEX_IAK_SHA384 0x01c90019

#define TPM2_EK_RSA_HANDLE 0x81010001
#define TPM2_EK_RSA3072_HANDLE 0x8101001c
#define TPM2_EK_ECC_SECP384R1_HANDLE 0x81010016
Expand Down Expand Up @@ -1045,6 +1049,17 @@ static int swtpm_tpm2_createprimary_ecc(struct swtpm *self, uint32_t primaryhand
tpmresp, &tpmresp_len, TPM2_DURATION_LONG);
if (ret != 0)
return 1;
#if 0
{
size_t x;
for (x = 0; x < tpmresp_len; x++) {
if (x % 0x10 == 0)
printf("\n");
printf("%02x ", tpmresp[x]);
}
printf("\n");
}
#endif
if (curr_handle) {
if (tpmresp_len < 10 + sizeof(*curr_handle))
goto err_too_short;
Expand Down Expand Up @@ -1123,6 +1138,86 @@ static int swtpm_tpm2_createprimary_spk_ecc_nist_p384(struct swtpm *self,
off, curr_handle, NULL, 0, NULL, NULL);
}

static int createprimary_iak_idevid_ecc_nist_p384(struct swtpm *self,
unsigned int keyflags,
const unsigned char *authpolicy, size_t authpolicy_len,
const unsigned char *id, size_t id_len,
size_t off, uint32_t *curr_handle,
gchar **keyparam, const gchar **key_description)
{
const unsigned char symkeydata[] = {AS2BE(TPM2_ALG_NULL)};
size_t symkeydata_len = sizeof(symkeydata);
const unsigned char schemedata[] = {
/* TPMS_ECC_PARAMS: TPMT_ECC_SCHEME .. TPMT_KDF_SCHEME */
AS2BE(TPM2_ALG_ECDSA),
AS2BE(TPM2_ALG_SHA384), // hashAlg
AS2BE(TPM2_ECC_NIST_P384), // curveID
AS2BE(TPM2_ALG_NULL), // kdf->scheme
};
size_t schemedata_len = sizeof(schemedata);

/* FIXME: unclear specification about nonces on ECCs */
return swtpm_tpm2_createprimary_ecc(self, TPM2_RH_ENDORSEMENT, keyflags,
symkeydata, symkeydata_len,
authpolicy, authpolicy_len,
schemedata, schemedata_len,
TPM2_ECC_NIST_P384, TPM2_ALG_SHA384,
id /* nonce1 */, id_len,
id /* nonce2 */, id_len,
off, curr_handle,
NULL, 0, keyparam, key_description);
}

static int
swtpm_tpm2_createprimary_idevid_ecc_nist_p384(struct swtpm *self,
uint32_t *curr_handle,
gchar **keyparam,
const gchar **key_description)
{
const unsigned char authpolicy[48] = {
/* table 19: signing */
0x4d, 0xb1, 0xaa, 0x83, 0x6d, 0x0b, 0x56, 0x15, 0xdf, 0x6e, 0xe5, 0x3a,
0x40, 0xef, 0x70, 0xc6, 0x1c, 0x21, 0x7f, 0x43, 0x03, 0xd4, 0x46, 0x95,
0x92, 0x59, 0x72, 0xbc, 0x92, 0x70, 0x06, 0xcf, 0xa5, 0xcb, 0xdf, 0x6d,
0xc1, 0x8c, 0x4d, 0xbe, 0x32, 0x9b, 0x2f, 0x15, 0x42, 0xc3, 0xdd, 0x33
};
size_t authpolicy_len = sizeof(authpolicy);
// 7.3.4.1 keyflags: fixedTPM, fixedParent, sensitiveDataOrigin, userWithAuth,
// adminWithPolicy, sign
unsigned int keyflags = 0x000400f2;
const char id[2 + 6] = {AS2BE(6), 0x49, 0x44, 0x45, 0x56, 0x49, 0x44}; /* 7.3.1 Table 2*/
size_t off = 0x58;

return createprimary_iak_idevid_ecc_nist_p384(self, keyflags, authpolicy, authpolicy_len,
(const unsigned char *)id, sizeof(id),
off, curr_handle, keyparam, key_description);
}

static int
swtpm_tpm2_createprimary_iak_ecc_nist_p384(struct swtpm *self,
uint32_t *curr_handle,
gchar **keyparam,
const gchar **key_description)
{
const unsigned char authpolicy[48] = {
/* table 19: attestation */
0x12, 0x9d, 0x94, 0xeb, 0xf8, 0x45, 0x56, 0x65, 0x2c, 0x6e, 0xef, 0x43,
0xbb, 0xb7, 0x57, 0x51, 0x2a, 0xc8, 0x7e, 0x52, 0xbe, 0x7b, 0x34, 0x9c,
0xa6, 0xce, 0x4d, 0x82, 0x6f, 0x74, 0x9f, 0xcf, 0x67, 0x2f, 0x51, 0x71,
0x6c, 0x5c, 0xbb, 0x60, 0x5f, 0x31, 0x3b, 0xf3, 0x45, 0xaa, 0xb3, 0x12
};
size_t authpolicy_len = sizeof(authpolicy);
// 7.3.4.1 keyflags: fixedTPM, fixedParent, sensitiveDataOrigin, userWithAuth,
// adminWithPolicy, restricted, sign
unsigned int keyflags = 0x000500f2;
const char id[2 + 3] = {AS2BE(3), 0x49, 0x41, 0x4b}; /* 7.3.1 Table 2 */
size_t off = 0x58;

return createprimary_iak_idevid_ecc_nist_p384(self, keyflags, authpolicy, authpolicy_len,
(const unsigned char *)id, sizeof(id),
off, curr_handle, keyparam, key_description);
}

static int swtpm_tpm2_createprimary_spk_rsa(struct swtpm *self, unsigned int rsa_keysize,
uint32_t *curr_handle)
{
Expand Down Expand Up @@ -1178,6 +1273,35 @@ static int swtpm_tpm2_create_spk(struct swtpm *self, gboolean isecc, unsigned in
return ret;
}

static int swtpm_tpm2_create_iak(struct swtpm *self, gchar **ekparam,
const gchar **key_description)
{
uint32_t curr_handle;
int ret;

ret = swtpm_tpm2_createprimary_iak_ecc_nist_p384(self, &curr_handle, ekparam,
key_description);
if (ret != 0)
return 1;

return swtpm_tpm2_flushcontext(self, curr_handle);
}

static int swtpm_tpm2_create_idevid(struct swtpm *self, gchar **ekparam,
const gchar **key_description)
{
uint32_t curr_handle;
int ret;

ret = swtpm_tpm2_createprimary_idevid_ecc_nist_p384(self, &curr_handle, ekparam,
key_description);
if (ret != 0)
return 1;

return swtpm_tpm2_flushcontext(self, curr_handle);
}


/* Create an ECC EK key that may be allowed to sign and/or decrypt */
static int swtpm_tpm2_createprimary_ek_ecc_nist_p384(struct swtpm *self, gboolean allowsigning,
gboolean decryption, uint32_t *curr_handle,
Expand Down Expand Up @@ -1518,15 +1642,51 @@ static char *swtpm_tpm2_get_active_profile(struct swtpm *self)
return result;
}

static int swtpm_tpm2_write_iak_cert_nvram(struct swtpm *self, gboolean lock_nvram,
const unsigned char *data, size_t data_len)
{
uint32_t nvindex = TPM2_NV_INDEX_IAK_SHA384;
uint32_t nvindexattrs = TPMA_NV_PLATFORMCREATE |
TPMA_NV_AUTHREAD |
TPMA_NV_OWNERREAD |
TPMA_NV_PPREAD |
TPMA_NV_PPWRITE |
TPMA_NV_NO_DA |
TPMA_NV_WRITEDEFINE; // FIXME: fix flags?

return swtpm_tpm2_write_cert_nvram(self, nvindex, nvindexattrs, data, data_len,
lock_nvram, "", "IAK certificate");
}

static int swtpm_tpm2_write_idevid_cert_nvram(struct swtpm *self, gboolean lock_nvram,
const unsigned char *data, size_t data_len)
{
uint32_t nvindex = TPM2_NV_INDEX_IDEVID_SHA384;
uint32_t nvindexattrs = TPMA_NV_PLATFORMCREATE |
TPMA_NV_AUTHREAD |
TPMA_NV_OWNERREAD |
TPMA_NV_PPREAD |
TPMA_NV_PPWRITE |
TPMA_NV_NO_DA |
TPMA_NV_WRITEDEFINE; // FIXME: fix flags?

return swtpm_tpm2_write_cert_nvram(self, nvindex, nvindexattrs, data, data_len,
lock_nvram, "", "IDevID certificate");
}

static const struct swtpm2_ops swtpm_tpm2_ops = {
.shutdown = swtpm_tpm2_shutdown,
.create_iak = swtpm_tpm2_create_iak,
.create_idevid = swtpm_tpm2_create_idevid,
.create_spk = swtpm_tpm2_create_spk,
.create_ek = swtpm_tpm2_create_ek,
.get_all_pcr_banks = swtpm_tpm2_get_all_pcr_banks,
.set_active_pcr_banks = swtpm_tpm2_set_active_pcr_banks,
.write_ek_cert_nvram = swtpm_tpm2_write_ek_cert_nvram,
.write_platform_cert_nvram = swtpm_tpm2_write_platform_cert_nvram,
.get_active_profile = swtpm_tpm2_get_active_profile,
.write_iak_cert_nvram = swtpm_tpm2_write_iak_cert_nvram,
.write_idevid_cert_nvram = swtpm_tpm2_write_idevid_cert_nvram,
};

/*
Expand Down
6 changes: 6 additions & 0 deletions src/swtpm_setup/swtpm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,8 @@ struct swtpm12_ops {
/* TPM 2 specific ops */
struct swtpm2_ops {
int (*shutdown)(struct swtpm *);
int (*create_iak)(struct swtpm *self, gchar **ekparam, const gchar **key_description);
int (*create_idevid)(struct swtpm *self, gchar **ekparam, const gchar **key_description);
int (*create_spk)(struct swtpm *self, gboolean isecc, unsigned int rsa_keysize);
int (*create_ek)(struct swtpm *self, gboolean isecc, unsigned int rsa_keysize,
gboolean allowsigning, gboolean decryption, gboolean lock_nvram,
Expand All @@ -57,6 +59,10 @@ struct swtpm2_ops {
int (*write_platform_cert_nvram)(struct swtpm *self, gboolean lock_nvram,
const unsigned char *data, size_t data_len);
char *(*get_active_profile)(struct swtpm *self);
int (*write_iak_cert_nvram)(struct swtpm *self, gboolean lock_nvram,
const unsigned char *data, size_t data_len);
int (*write_idevid_cert_nvram)(struct swtpm *self, gboolean lock_nvram,
const unsigned char *data, size_t data_len);
};

/* common structure for swtpm object */
Expand Down
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