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Bug fix ECC and persistent storage in OPTEE

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Fixes two bugs in the OP-TEE port

1. WTPI_GetBootCertificateChain() did not correctly zero pad ECC keys
   that are smaller than 32 bytes.
2. wtpi_persistent_storage_layer2.c:write_raw_object() would overwrite
   objects if an initial read failed.
This commit is contained in:
Matt Feddersen
2023-12-08 18:35:46 -08:00
parent c259630b75
commit 6cd8677952
2 changed files with 38 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
oemcrypto/opk/ports/optee/ta/common/wtpi_impl/wtpi_persistent_storage_layer2.c
View File

@@ -26,18 +26,25 @@ static TEE_Result write_raw_object(const char* obj_id, size_t obj_id_length,
* Create object in secure storage and fill with data
*/
obj_data_flag =
TEE_DATA_FLAG_ACCESS_READ | /* we can later read the oject */
TEE_DATA_FLAG_ACCESS_WRITE | /* we can later write into the object */
TEE_DATA_FLAG_ACCESS_WRITE_META | /* we can later destroy or rename the
object */
TEE_DATA_FLAG_OVERWRITE; /* destroy existing object of same ID */
TEE_DATA_FLAG_ACCESS_READ | /* we can later read the oject */
TEE_DATA_FLAG_ACCESS_WRITE | /* we can later write into the object */
TEE_DATA_FLAG_ACCESS_WRITE_META; /* we can later destroy or rename the
object */
res = TEE_CreatePersistentObject(TEE_STORAGE_PRIVATE, obj_id, obj_id_length,
obj_data_flag, TEE_HANDLE_NULL, NULL,
0, /* we may not fill it right now */
&object);
if (res != TEE_SUCCESS) {
EMSG("TEE_CreatePersistentObject failed 0x%08x", res);
res = TEE_OpenPersistentObject(TEE_STORAGE_PRIVATE, obj_id,
obj_id_length, obj_data_flag, &object);
if (res == TEE_ERROR_ITEM_NOT_FOUND) {
res = TEE_CreatePersistentObject(
TEE_STORAGE_PRIVATE, obj_id, obj_id_length, obj_data_flag,
TEE_HANDLE_NULL, NULL, 0, /* we may not fill it right now */
&object);
if (res != TEE_SUCCESS) {
EMSG("TEE_CreatePersistentObject failed 0x%08x", res);
TEE_Free(data);
return res;
}
} else if (res != TEE_SUCCESS) {
EMSG("Failed to open persistent object, res=0x%08x", res);
TEE_Free(data);
return res;
}
@@ -86,6 +93,12 @@ static TEE_Result read_raw_object(const char* obj_id, size_t obj_id_length,
goto exit;
}
if (object_info.dataSize == 0) {
res = TEE_ERROR_ITEM_NOT_FOUND;
EMSG("Failed to read persistent object, res=0x%08x, dataSize=0", res);
goto exit;
}
res = TEE_ReadObjectData(object, data, object_info.dataSize, &read_bytes);
if (res == TEE_SUCCESS) TEE_MemMove(out, data, read_bytes);
if (res != TEE_SUCCESS || read_bytes != object_info.dataSize) {

18
oemcrypto/opk/ports/optee/ta/common/wtpi_impl/wtpi_provisioning_4.c
View File

@@ -293,26 +293,36 @@ OEMCryptoResult WTPI_GetBootCertificateChain(uint8_t* out, size_t* out_length) {
}
// extract public key, P256 hardcoded to 64 bytes long
uint8_t public_key[64];
uint8_t public_key[64] = {0};
uint8_t temp[32] = {0};
size_t public_key_length = sizeof(public_key);
size_t buf_size = 32;
TEE_Result tee_res = TEE_GetObjectBufferAttribute(
private_key_handle->key_handle, TEE_ATTR_ECC_PUBLIC_VALUE_X, public_key,
private_key_handle->key_handle, TEE_ATTR_ECC_PUBLIC_VALUE_X, temp,
&buf_size);
if (tee_res != TEE_SUCCESS) {
EMSG("TEE_GetObjectBufferAttribute() failed with result 0x%x", tee_res);
WTPI_FreeAsymmetricKeyHandle(private_key_handle);
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
// buf_size is modified to indicate the actual size of the X component.
// Move the data so that it has leading zeros if it is less than 32 bytes.
TEE_MemMove(public_key + 32 - buf_size, temp, buf_size);
buf_size = 32;
TEE_MemFill(temp, 0, sizeof(temp));
tee_res = TEE_GetObjectBufferAttribute(private_key_handle->key_handle,
TEE_ATTR_ECC_PUBLIC_VALUE_Y,
public_key + 32, &buf_size);
TEE_ATTR_ECC_PUBLIC_VALUE_Y, temp,
&buf_size);
if (tee_res != TEE_SUCCESS) {
EMSG("TEE_GetObjectBufferAttribute() failed with result 0x%x", tee_res);
WTPI_FreeAsymmetricKeyHandle(private_key_handle);
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
TEE_MemMove(public_key + 64 - buf_size, temp, buf_size);
result = BuildBootCertificateChain(public_key, public_key_length, key_type,
private_key_handle, out, out_length);
WTPI_FreeAsymmetricKeyHandle(private_key_handle);