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Atmosphere/exosphere/smc_api.c
2018-02-22 19:58:39 -08:00

418 lines
12 KiB
C

#include <stdint.h>
#include "utils.h"
#include "configitem.h"
#include "cpu_context.h"
#include "smc_api.h"
#include "smc_user.h"
#include "se.h"
#include "userpage.h"
#include "titlekey.h"
#define SMC_USER_HANDLERS 0x13
#define SMC_PRIV_HANDLERS 0x9
/* User SMC prototypes */
uint32_t smc_set_config(smc_args_t *args);
uint32_t smc_get_config(smc_args_t *args);
uint32_t smc_check_status(smc_args_t *args);
uint32_t smc_get_result(smc_args_t *args);
uint32_t smc_exp_mod(smc_args_t *args);
uint32_t smc_get_random_bytes_for_user(smc_args_t *args);
uint32_t smc_generate_aes_kek(smc_args_t *args);
uint32_t smc_load_aes_key(smc_args_t *args);
uint32_t smc_crypt_aes(smc_args_t *args);
uint32_t smc_generate_specific_aes_key(smc_args_t *args);
uint32_t smc_compute_cmac(smc_args_t *args);
uint32_t smc_load_rsa_oaep_key(smc_args_t *args);
uint32_t smc_decrypt_rsa_private_key(smc_args_t *args);
uint32_t smc_load_secure_exp_mod_key(smc_args_t *args);
uint32_t smc_secure_exp_mod(smc_args_t *args);
uint32_t smc_unwrap_rsa_oaep_wrapped_titlekey(smc_args_t *args);
uint32_t smc_load_titlekey(smc_args_t *args);
uint32_t smc_unwrap_aes_wrapped_titlekey(smc_args_t *args);
/* Privileged SMC prototypes */
uint32_t smc_cpu_suspend(smc_args_t *args);
uint32_t smc_cpu_off(smc_args_t *args);
uint32_t smc_cpu_on(smc_args_t *args);
/* uint32_t smc_get_config(smc_args_t *args); */
uint32_t smc_get_random_bytes_for_priv(smc_args_t *args);
uint32_t smc_panic(smc_args_t *args);
uint32_t smc_configure_carveout(smc_args_t *args);
uint32_t smc_read_write_register(smc_args_t *args);
typedef struct {
uint32_t id;
uint32_t (*handler)(smc_args_t *args);
} smc_table_entry_t;
typedef struct {
smc_table_entry_t *handlers;
uint32_t num_handlers;
} smc_table_t;
smc_table_entry_t g_smc_user_table[SMC_USER_HANDLERS] = {
{0, NULL},
{0xC3000401, smc_set_config},
{0xC3000002, smc_get_config},
{0xC3000003, smc_check_status},
{0xC3000404, smc_get_result},
{0xC3000E05, smc_exp_mod},
{0xC3000006, smc_get_random_bytes_for_user},
{0xC3000007, smc_generate_aes_kek},
{0xC3000008, smc_load_aes_key},
{0xC3000009, smc_crypt_aes},
{0xC300000A, smc_generate_specific_aes_key},
{0xC300040B, smc_compute_cmac},
{0xC300100C, smc_load_rsa_oaep_key},
{0xC300100D, smc_decrypt_rsa_private_key},
{0xC300100E, smc_load_secure_exp_mod_key},
{0xC300060F, smc_secure_exp_mod},
{0xC3000610, smc_unwrap_rsa_oaep_wrapped_titlekey},
{0xC3000011, smc_load_titlekey},
{0xC3000012, smc_unwrap_aes_wrapped_titlekey}
};
smc_table_entry_t g_smc_priv_table[SMC_PRIV_HANDLERS] = {
{0, NULL},
{0xC4000001, smc_cpu_suspend},
{0x84000002, smc_cpu_off},
{0xC4000003, smc_cpu_on},
{0xC3000004, smc_get_config}, /* NOTE: Same function as for USER */
{0xC3000005, smc_get_random_bytes_for_priv},
{0xC3000006, smc_panic},
{0xC3000007, smc_configure_carveout},
{0xC3000008, smc_read_write_register}
};
smc_table_t g_smc_tables[2] = {
{ /* SMC_HANDLER_USER */
g_smc_user_table,
SMC_USER_HANDLERS
},
{ /* SMC_HANDLER_PRIV */
g_smc_priv_table,
SMC_PRIV_HANDLERS
}
};
bool g_is_smc_in_progress = false;
uint32_t (*g_smc_callback)(void *, uint64_t) = NULL;
uint64_t g_smc_callback_key = 0;
uint64_t try_set_smc_callback(uint32_t (*callback)(void *, uint64_t)) {
uint64_t key;
/* TODO: Atomics... */
if (g_smc_callback_key) {
return 0;
}
se_generate_random(KEYSLOT_SWITCH_RNGKEY, &key, sizeof(uint64_t));
g_smc_callback_key = key;
g_smc_callback = callback;
return key;
}
void clear_smc_callback(uint64_t key) {
/* TODO: Atomics... */
if (g_smc_callback_key == key) {
g_smc_callback_key = 0;
}
}
void call_smc_handler(uint32_t handler_id, smc_args_t *args) {
unsigned char smc_id;
unsigned int result;
unsigned int (*smc_handler)(smc_args_t *args);
/* Validate top-level handler. */
if (handler_id != SMC_HANDLER_USER && handler_id != SMC_HANDLER_PRIV) {
panic();
}
/* Validate core is appropriate for handler. */
if (handler_id == SMC_HANDLER_USER && get_core_id() != 3) {
/* USER SMCs must be called via svcCallSecureMonitor on core 3 (where spl runs) */
panic();
}
/* Validate sub-handler index */
if ((smc_id = (unsigned char)args->X[0]) >= g_smc_tables[handler_id].num_handlers) {
panic();
}
/* Validate sub-handler */
if (g_smc_tables[handler_id].handlers[smc_id].id != args->X[0]) {
panic();
}
/* Validate handler. */
if ((smc_handler = g_smc_tables[handler_id].handlers[smc_id].handler) == NULL) {
panic();
}
/* Call function. */
args->X[0] = smc_handler(args);
}
uint32_t smc_wrapper_sync(smc_args_t *args, uint32_t (*handler)(smc_args_t *)) {
uint32_t result;
/* TODO: Make g_is_smc_in_progress atomic. */
if (g_is_smc_in_progress) {
return 3;
}
g_is_smc_in_progress = true;
result = handler(args);
g_is_smc_in_progress = false;
return result;
}
uint32_t smc_wrapper_async(smc_args_t *args, uint32_t (*handler)(smc_args_t *), uint32_t (*callback)(void *, uint64_t)) {
uint32_t result;
uint64_t key;
/* TODO: Make g_is_smc_in_progress atomic. */
if (g_is_smc_in_progress) {
return 3;
}
g_is_smc_in_progress = 1;
if ((key = try_set_smc_callback(callback)) != 0) {
result = handler(args);
if (result == 0) {
/* Pass the status check key back to userland. */
args->X[1] = key;
/* Early return, leaving g_is_smc_in_progress == 1 */
return result;
} else {
/* No status to check. */
clear_smc_callback(key);
}
} else {
/* smcCheckStatus needs to be called. */
result = 3;
}
g_is_smc_in_progress = false;
return result;
}
uint32_t smc_set_config(smc_args_t *args) {
/* Actual value presumed in X3 on hardware. */
return configitem_set((enum ConfigItem)args->X[1], args->X[3]);
}
uint32_t smc_get_config(smc_args_t *args) {
uint64_t out_item = 0;
uint32_t result;
result = configitem_get((enum ConfigItem)args->X[1], &out_item);
args->X[1] = out_item;
return result;
}
uint32_t smc_check_status(smc_args_t *args) {
if (g_smc_callback_key == 0) {
return 4;
}
if (args->X[1] != g_smc_callback_key) {
return 5;
}
args->X[1] = g_smc_callback(NULL, 0);
g_smc_callback_key = 0;
return 0;
}
uint32_t smc_get_result(smc_args_t *) {
uint32_t status;
unsigned char result_buf[0x400];
upage_ref_t page_ref;
void *user_address = (void *)args->X[2];
if (g_smc_callback_key == 0) {
return 4;
}
if (args->X[1] != g_smc_callback_key) {
return 5;
}
/* Check result size */
if (args->X[3] > 0x400) {
return 2;
}
args->X[1] = g_smc_callback(result_buf, args->X[3]);
g_smc_callback_key = 0;
/* Initialize page reference. */
if (upage_init(&page_ref, user_address) == 0) {
return 2;
}
/* Copy result output back to user. */
if (secure_copy_to_user(&page_ref, user_address, result_buf, (size_t)args->X[3]) == 0) {
return 2;
}
return 0;
}
uint32_t smc_exp_mod_get_result(void *buf, uint64_t size) {
if (get_exp_mod_done() != 1) {
return 3;
}
if (size != 0x100) {
return 2;
}
se_get_exp_mod_output(buf, 0x100);
/* smc_exp_mod is done now. */
g_is_smc_in_progress = false;
return 0;
}
uint32_t smc_exp_mod(smc_args_t *args) {
return smc_wrapper_async(args, user_exp_mod, smc_exp_mod_get_result);
}
uint32_t smc_get_random_bytes_for_user(smc_args_t *args) {
return smc_wrapper_sync(args, user_get_random_bytes);
}
uint32_t smc_generate_aes_kek(smc_args_t *args) {
return smc_wrapper_sync(args, user_generate_aes_kek);
}
uint32_t smc_load_aes_key(smc_args_t *args) {
return smc_wrapper_sync(args, user_load_aes_key);
}
uint32_t smc_crypt_aes_status_check(void *buf, uint64_t size) {
/* Buf and size are unused. */
if (get_crypt_aes_done() != 1) {
return 3;
}
/* smc_crypt_aes is done now. */
g_is_smc_in_progress = false;
return 0;
}
uint32_t smc_crypt_aes(smc_args_t *args) {
return smc_wrapper_async(args, user_crypt_aes, smc_crypt_aes_status_check);
}
uint32_t smc_generate_specific_aes_key(smc_args_t *args) {
return smc_wrapper_sync(args, user_generate_specific_aes_key);
}
uint32_t smc_compute_cmac(smc_args_t *args) {
return smc_wrapper_sync(args, user_compute_cmac);
}
uint32_t smc_load_rsa_oaep_key(smc_args_t *args) {
return smc_wrapper_sync(args, user_load_rsa_oaep_key);
}
uint32_t smc_decrypt_rsa_private_key(smc_args_t *args) {
return smc_wrapper_sync(args, user_decrypt_rsa_private_key);
}
uint32_t smc_load_secure_exp_mod_key(smc_args_t *args) {
return smc_wrapper_sync(args, user_load_secure_exp_mod_key);
}
uint32_t smc_secure_exp_mod(smc_args_t *args) {
return smc_wrapper_async(args, user_secure_exp_mod, smc_exp_mod_get_result);
}
uint32_t smc_unwrap_rsa_oaep_wrapped_titlekey_get_result(void *buf, uint64_t size) {
uint64_t *p_sealed_key = (uint64_t *)buf;
uint8_t rsa_wrapped_titlekey[0x100];
uint8_t aes_wrapped_titlekey[0x10];
uint8_t titlekey[0x10];
uint64_t sealed_titlekey[2];
if (get_exp_mod_done() != 1) {
return 3;
}
if (size != 0x10) {
return 2;
}
se_get_exp_mod_output(wrapped_titlekey, 0x100);
if (tkey_rsa_oaep_unwrap(aes_wrapped_titlekey, 0x10, rsa_wrapped_titlekey, 0x100) != 0x10) {
/* Failed to extract RSA OAEP wrapped key. */
g_is_smc_in_progress = false;
return 2;
}
tkey_aes_unwrap(titlekey, 0x10, aes_wrapped_titlekey, 0x10);
seal_titlekey(sealed_titlekey, 0x10, titlekey, 0x10);
p_sealed_key[0] = sealed_titlekey[0];
p_sealed_key[1] = sealed_titlekey[1];
/* smc_unwrap_rsa_oaep_wrapped_titlekey is done now. */
g_is_smc_in_progress = false;
return 0;
}
uint32_t smc_unwrap_rsa_oaep_wrapped_titlekey(smc_args_t *args) {
return smc_wrapper_async(args, user_unwrap_rsa_oaep_wrapped_titlekey, smc_unwrap_rsa_oaep_wrapped_titlekey_get_result);
}
uint32_t smc_load_titlekey(smc_args_t *args) {
return smc_wrapper_sync(args, user_load_titlekey);
}
uint32_t smc_unwrap_aes_wrapped_titlekey(smc_args_t *args) {
return smc_wrapper_sync(args, user_unwrap_aes_wrapped_titlekey);
}
uint32_t smc_cpu_on(smc_args_t *args) {
return cpu_on((uint32_t)args->X[1], args->X[2], args->X[3]);
}
uint32_t smc_cpu_off(smc_args_t *args) {
return cpu_off();
}
/* Wrapper for cpu_suspend */
uint32_t cpu_suspend_wrapper(smc_args_t *args) {
return cpu_suspend(args->X[1], args->X[2], args->X[3]);
}
uint32_t smc_cpu_suspend(smc_args_t *args) {
return smc_wrapper_sync(args, cpu_suspend_wrapper);
}
uint32_t smc_get_random_bytes_for_priv(smc_args_t *args) {
/* This is an interesting SMC. */
/* The kernel must NEVER be unable to get random bytes, if it needs them */
/* As such: */
uint32_t result;
/* TODO: Make atomic. */
if (g_is_smc_in_progress) {
if (args->X[1] > 0x38) {
return 2;
}
/* Retrieve bytes from the cache. */
size_t num_bytes = (size_t)args->X[1];
randomcache_getbytes(&args->X[1], num_bytes);
result = 0;
} else {
g_is_smc_in_progress = true;
/* If the kernel isn't denied service by a usermode SMC, generate fresh random bytes. */
result = user_get_random_bytes(args);
/* Also, refill our cache while we have the chance in case we get denied later. */
randomcache_refill();
g_is_smc_in_progress = false;
}
return result;
}