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tpm2_nvread: use libyaml
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Signed-off-by: Bill Roberts <[email protected]>
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@williamcroberts
williamcroberts committed Dec 10, 2023
1 parent 9cad578 commit 2da4e3a
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Showing 3 changed files with 139 additions and 9 deletions.
139 changes: 133 additions & 6 deletions lib/tpm2_yaml.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,8 @@

#include <yaml.h>

#include <tss2/tss2_mu.h>

#include "log.h"
#include "tool_rc.h"
#include "tpm2_alg_util.h"
Expand Down Expand Up @@ -117,9 +119,9 @@ static int yaml_add_int(tpm2_yaml *y, uint64_t data, unsigned base) {

/*
* 8 bytes for 64 bit nums, times two for 2 chars per byte in hex,
* and a nul byte
* and a nul byte and extra bytes for the fmt string
*/
char buf[8 * 2 + 1] = { 0 };
char buf[128] = { 0 };

const char *fmt = NULL;
switch(base) {
Expand Down Expand Up @@ -151,10 +153,21 @@ static int yaml_add_tpm2b(tpm2_yaml *y, const TPM2B *data) {
LOG_ERR("oom");
return 0;
}

/* prefix bytes of 0x and nul byte */
size_t len = strlen(h) + 2 + 1;
char *prefixed = calloc(1, len);
if (!prefixed) {
free(h);
return 0;
}
snprintf(prefixed, len, "0x%s", h);
free(h);

y->written = 1;
int node = yaml_document_add_scalar(&y->doc, (yaml_char_t *)YAML_STR_TAG,
h, -1, YAML_ANY_SCALAR_STYLE);
free(h);
prefixed, -1, YAML_ANY_SCALAR_STYLE);
free(prefixed);

return node;
}
Expand Down Expand Up @@ -182,8 +195,7 @@ static int add_kvp(tpm2_yaml *y, int root, const key_value *k) {
}
return_rc(value);

int rc = yaml_document_append_mapping_pair(&y->doc, root, key, value);
return_rc(rc);
return yaml_document_append_mapping_pair(&y->doc, root, key, value);
}

static int add_kvp_list(tpm2_yaml *y, int root, const key_value *kvs, size_t len) {
Expand Down Expand Up @@ -628,12 +640,127 @@ tool_rc tpm2_yaml_tpm_alg_todo(tpm2_yaml *y, const TPML_ALG *to_do_list) {
}

tool_rc tpm2_yaml_tpm2_nv_index(tpm2_yaml *y, TPM2_NV_INDEX index) {
null_ret(y, 1);
assert(index);

struct key_value kvp = KVP_ADD_HEX("nv-index", index);
return add_kvp(y, y->root, &kvp) ?
tool_rc_success : tool_rc_general_error;
}

static int tpms_nv_pin_counter_parameters_to_yaml_raw(tpm2_yaml *y,
int root, const char *key, const uint8_t *data, size_t data_len) {
/*
* <key>:
* pinCount: 1
* pinLimit: 3
*/
TPMS_NV_PIN_COUNTER_PARAMETERS pin_params = { 0 };
TSS2_RC rc = Tss2_MU_TPMS_NV_PIN_COUNTER_PARAMETERS_Unmarshal(data, data_len,
NULL, &pin_params);
if (rc != TSS2_RC_SUCCESS) {
return 0;
}

key_value scheme_kvs[] = {
KVP_ADD_INT("pinCount", pin_params.pinCount),
KVP_ADD_INT("pinLimit", pin_params.pinLimit),
};

return add_mapping_root_with_items(y, root, key,
scheme_kvs, ARRAY_LEN(scheme_kvs));}

static int tpm2_nv_read_to_yaml(tpm2_yaml *y, const TPMS_NV_PUBLIC *pub, const uint8_t *data,
size_t data_len) {

TPM2_NT nt = (pub->attributes & TPMA_NV_TPM2_NT_MASK) >> TPMA_NV_TPM2_NT_SHIFT;
switch (nt) {
case TPM2_NT_COUNTER: {
if (data_len != sizeof(UINT64)) {
LOG_ERR("Unexpected size for TPM2_NV_COUNTER of %u bytes, expected %u",
data_len, sizeof(UINT64));
return 0;
}
UINT64 v = 0;
memcpy(&v, data, sizeof(UINT64));
v = be64toh(v);
struct key_value kvp = KVP_ADD_INT("counter", v);
return add_kvp(y, y->root, &kvp);
}
case TPM2_NT_BITS: {
if (data_len != sizeof(UINT64)) {
LOG_ERR("Unexpected size for TPM2_NV_BITS of %u bytes, expected %u",
data_len, sizeof(UINT64));
return 0;
}

UINT64 v = 0;
memcpy(&v, data, sizeof(UINT64));
v = be64toh(v);
struct key_value kvp = KVP_ADD_HEX("bits", v);
return add_kvp(y, y->root, &kvp);
}
case TPM2_NT_EXTEND: {

/*
* 8 bytes for 64 bit nums, times two for 2 chars per byte in hex,
* and a nul byte and extra for the format
*/
char buf[128] = { 0 };

/* plop data into a TPM2B structure to make outputiting to hex easier */
TPM2B_DIGEST d = {
.size = data_len,
};
if (data_len > sizeof(d.buffer)) {
LOG_ERR("Read data is larger than buffer, got %u expected less than %zu",
data_len, sizeof(d.buffer));
return 0;
}
memcpy(d.buffer, data, data_len);

/* convert index to 0x<index> */
snprintf(buf, sizeof(buf), "0x%"PRIx64, pub->nvIndex);

const char *algstr = tpm2_alg_util_algtostr(pub->nameAlg, tpm2_alg_util_flags_any);
struct key_value kvp = KVP_ADD_TPM2B(algstr, &d);
return add_kvp(y, y->root, &kvp);
}
break;
case TPM2_NT_PIN_FAIL:
return tpms_nv_pin_counter_parameters_to_yaml_raw(y, y->root, "pinfail", data, data_len);
case TPM2_NT_PIN_PASS:
return tpms_nv_pin_counter_parameters_to_yaml_raw(y, y->root, "pinpass", data, data_len);
/* no default - keep compilers happy */
default:
break;
}

/* copy data to a simple TPM2B to make outputting easier */
TPM2B_MAX_NV_BUFFER b = {
.size = data_len
};

if (data_len > sizeof(b.buffer)) {
LOG_ERR("Read data is larger than buffer, got %u expected less than %zu",
data_len, sizeof(b.buffer));
return 0;
}
memcpy(b.buffer, data, data_len);
struct key_value kvp = KVP_ADD_TPM2B("data", &b);
return add_kvp(y, y->root, &kvp);
}

tool_rc tpm2_yaml_nv_read(const char *data, size_t data_len, const TPM2B_NV_PUBLIC *nv_public,
tpm2_yaml *y) {
null_ret(y, 1);
assert(data);
assert(nv_public);

return tpm2_nv_read_to_yaml(y, &nv_public->nvPublic, data, data_len) ?
tool_rc_success : tool_rc_general_error;
}

tool_rc tpm2_yaml_dump(tpm2_yaml *y, FILE *f) {
assert(y);
assert(f);
Expand Down
3 changes: 3 additions & 0 deletions lib/tpm2_yaml.h
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,9 @@ tool_rc tpm2_yaml_tpml_alg(tpm2_yaml *y, const TPML_ALG *alg_list);

tool_rc tpm2_yaml_tpm2_nv_index(tpm2_yaml *y, TPM2_NV_INDEX index);

tool_rc tpm2_yaml_nv_read(const char *data, size_t data_len, const TPM2B_NV_PUBLIC *nv_public,
tpm2_yaml *y);

tool_rc tpm2_yaml_dump(tpm2_yaml *y, FILE *f);

#endif /* LIB_TPM2_YAML_H_ */
6 changes: 3 additions & 3 deletions tools/tpm2_nvread.c
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Original file line number Diff line number Diff line change
Expand Up @@ -69,7 +69,7 @@ static tool_rc nv_read(ESYS_CONTEXT *ectx) {
ctx.aux_session_handle[0], ctx.aux_session_handle[1], &ctx.nv_public);
}

static tool_rc process_output(ESYS_CONTEXT *ectx, tpm2_option_flags flags) {
static tool_rc process_output(ESYS_CONTEXT *ectx, tpm2_option_flags flags, tpm2_yaml *doc) {

UNUSED(ectx);
/*
Expand All @@ -95,7 +95,7 @@ static tool_rc process_output(ESYS_CONTEXT *ectx, tpm2_option_flags flags) {
/* dump ctx.data_buffer to output file, if specified */
tool_rc rc = tool_rc_success;
if (ctx.is_yaml) {
tpm2_util_tpm2_nv_to_yaml(ctx.nv_public, ctx.data_buffer, ctx.bytes_written, 0);
return tpm2_yaml_nv_read(ctx.data_buffer, ctx.bytes_written, ctx.nv_public, doc);
} else if (ctx.output_file) {
if (!files_save_bytes_to_file(ctx.output_file, ctx.data_buffer,
ctx.bytes_written)) {
Expand Down Expand Up @@ -407,7 +407,7 @@ static tool_rc tpm2_tool_onrun(ESYS_CONTEXT *ectx, tpm2_yaml *doc, tpm2_option_f
/*
* 4. Process outputs
*/
return process_output(ectx, flags);
return process_output(ectx, flags, doc);
}

static tool_rc tpm2_tool_onstop(ESYS_CONTEXT *ectx) {
Expand Down

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