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fix the salt value in export/import function.
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Signed-off-by: Jiewen Yao <[email protected]>
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@jyao1
jyao1 committed Aug 19, 2023
1 parent 567b1c8 commit 9deb023
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Showing 3 changed files with 43 additions and 0 deletions.
1 change: 1 addition & 0 deletions include/library/spdm_secured_message_lib.h
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Original file line number Diff line number Diff line change
Expand Up @@ -90,6 +90,7 @@ void libspdm_secured_message_clear_export_master_secret(void *spdm_secured_messa
#define LIBSPDM_SECURE_SESSION_KEYS_STRUCT_VERSION 1

#pragma pack(1)
/* sequence_number is the one that is not used in AEAD yet. */
typedef struct {
uint32_t version;
uint32_t aead_key_size;
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30 changes: 30 additions & 0 deletions library/spdm_secured_message_lib/libspdm_secmes_context_data.c
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Original file line number Diff line number Diff line change
Expand Up @@ -250,6 +250,7 @@ bool libspdm_secured_message_export_session_keys(void *spdm_secured_message_cont
size_t struct_size;
libspdm_secure_session_keys_struct_t *session_keys_struct;
uint8_t *ptr;
uint64_t data64;

secured_message_context = spdm_secured_message_context;
struct_size = sizeof(libspdm_secure_session_keys_struct_t) +
Expand All @@ -276,6 +277,12 @@ bool libspdm_secured_message_export_session_keys(void *spdm_secured_message_cont
*session_keys_size - (ptr - (uint8_t*)session_keys),
secured_message_context->application_secret.request_data_salt,
secured_message_context->aead_iv_size);
/* "salt ^ (sequence_number - 1)" is the original AEAD IV derived from SPDM key schedule. */
if (secured_message_context->application_secret.request_data_sequence_number > 0) {
data64 = libspdm_read_uint64((const uint8_t *)ptr) ^
(secured_message_context->application_secret.request_data_sequence_number - 1);
libspdm_write_uint64(ptr, data64);
}
ptr += secured_message_context->aead_iv_size;
libspdm_copy_mem(ptr,
*session_keys_size - (ptr - (uint8_t*)session_keys),
Expand All @@ -291,6 +298,12 @@ bool libspdm_secured_message_export_session_keys(void *spdm_secured_message_cont
*session_keys_size - (ptr - (uint8_t*)session_keys),
secured_message_context->application_secret.response_data_salt,
secured_message_context->aead_iv_size);
/* "salt ^ (sequence_number - 1)" is the original AEAD IV derived from SPDM key schedule. */
if (secured_message_context->application_secret.response_data_sequence_number > 0) {
data64 = libspdm_read_uint64((const uint8_t *)ptr) ^
(secured_message_context->application_secret.response_data_sequence_number - 1);
libspdm_write_uint64(ptr, data64);
}
ptr += secured_message_context->aead_iv_size;
libspdm_copy_mem(ptr,
*session_keys_size - (ptr - (uint8_t*)session_keys),
Expand Down Expand Up @@ -318,6 +331,7 @@ libspdm_secured_message_import_session_keys(void *spdm_secured_message_context,
size_t struct_size;
const libspdm_secure_session_keys_struct_t *session_keys_struct;
const uint8_t *ptr;
uint64_t data64;

secured_message_context = spdm_secured_message_context;
struct_size = sizeof(libspdm_secure_session_keys_struct_t) +
Expand Down Expand Up @@ -348,6 +362,14 @@ libspdm_secured_message_import_session_keys(void *spdm_secured_message_context,
sizeof(secured_message_context->application_secret
.request_data_salt),
ptr, secured_message_context->aead_iv_size);
/* "salt ^ (sequence_number - 1)" is the original AEAD IV derived from SPDM key schedule. */
if (secured_message_context->application_secret.request_data_sequence_number > 0) {
data64 =
libspdm_read_uint64(secured_message_context->application_secret.request_data_salt) ^
(secured_message_context->application_secret.request_data_sequence_number - 1);
libspdm_write_uint64(secured_message_context->application_secret.request_data_salt,
data64);
}
ptr += secured_message_context->aead_iv_size;
libspdm_copy_mem(&secured_message_context->application_secret.request_data_sequence_number,
sizeof(secured_message_context->application_secret
Expand All @@ -363,6 +385,14 @@ libspdm_secured_message_import_session_keys(void *spdm_secured_message_context,
libspdm_copy_mem(secured_message_context->application_secret.response_data_salt,
sizeof(secured_message_context->application_secret.response_data_salt),
ptr, secured_message_context->aead_iv_size);
/* "salt ^ (sequence_number - 1)" is the original AEAD IV derived from SPDM key schedule. */
if (secured_message_context->application_secret.response_data_sequence_number > 0) {
data64 =
libspdm_read_uint64(secured_message_context->application_secret.response_data_salt) ^
(secured_message_context->application_secret.response_data_sequence_number - 1);
libspdm_write_uint64(secured_message_context->application_secret.response_data_salt,
data64);
}
ptr += secured_message_context->aead_iv_size;
libspdm_copy_mem(&secured_message_context->application_secret.response_data_sequence_number,
sizeof(secured_message_context->application_secret
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12 changes: 12 additions & 0 deletions library/spdm_secured_message_lib/libspdm_secmes_encode_decode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -127,6 +127,11 @@ libspdm_return_t libspdm_encode_secured_message(
}

if (sequence_number > 0) {
/*
* "salt" is previous AEAD IV.
* "salt ^ (sequence_number - 1)" is the original AEAD IV derived from SPDM key schedule.
* "salt ^ (sequence_number - 1) ^ sequence_number" is the current AEAD IV.
*/
data64 = libspdm_read_uint64((const uint8_t *)salt) ^
(sequence_number - 1) ^ sequence_number;
libspdm_write_uint64(salt, data64);
Expand All @@ -137,6 +142,7 @@ libspdm_return_t libspdm_encode_secured_message(
sequence_number, (uint8_t *)&sequence_num_in_header);
LIBSPDM_ASSERT(sequence_num_in_header_size <= sizeof(sequence_num_in_header));

/* calculate sequence_number for the next round AEAD */
sequence_number++;
if (session_state == LIBSPDM_SESSION_STATE_HANDSHAKING) {
if (is_request_message) {
Expand Down Expand Up @@ -398,6 +404,11 @@ libspdm_return_t libspdm_decode_secured_message(
}

if (sequence_number > 0) {
/*
* "salt" is previous AEAD IV.
* "salt ^ (sequence_number - 1)" is the original AEAD IV derived from SPDM key schedule.
* "salt ^ (sequence_number - 1) ^ sequence_number" is the current AEAD IV.
*/
data64 = libspdm_read_uint64((const uint8_t *)salt) ^
(sequence_number - 1) ^ sequence_number;
libspdm_write_uint64(salt, data64);
Expand All @@ -409,6 +420,7 @@ libspdm_return_t libspdm_decode_secured_message(
sequence_number, (uint8_t *)&sequence_num_in_header);
LIBSPDM_ASSERT(sequence_num_in_header_size <= sizeof(sequence_num_in_header));

/* calculate sequence_number for the next round AEAD */
sequence_number++;
if (session_state == LIBSPDM_SESSION_STATE_HANDSHAKING) {
if (is_request_message) {
Expand Down

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