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Crypto v2 draft working

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This commit is contained in:
jaseg 2020-03-10 12:20:55 +01:00
parent 6880468862
commit 0cd07d397f
8 changed files with 211 additions and 135 deletions
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78
controller/fw/src/crypto.c
View file

@ -1,16 +1,22 @@
#include <assert.h>
#include <unistd.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <aes.h>
#include <sodium.h>
#include "crypto.h"
#include "simulation.h"
void debug_hexdump(const char *name, uint8_t *buf, size_t len);
void debug_hexdump(const char *name, uint8_t *buf, size_t len) {
void debug_hexdump(const char *name, const uint8_t *buf, size_t len);
int verify_trigger_dom(const uint8_t inkey[PRESIG_MSG_LEN],
const char *domain_string, const uint8_t refkey[PRESIG_MSG_LEN]);
void debug_hexdump(const char *name, const uint8_t *buf, size_t len) {
DEBUG_PRINTN("%20s: ", name);
for (size_t i=0; i<len;) {
for (size_t j=0; j<8 && i<len; i++, j++)
@ -20,28 +26,54 @@ void debug_hexdump(const char *name, uint8_t *buf, size_t len) {
DEBUG_PRINTN("\n");
}
int oob_message_received(uint8_t msg[static OOB_TRIGGER_LEN]) {
struct AES_ctx ctx;
uint8_t buf[crypto_sign_BYTES];
/* Returns 1 for correct trigger */
int verify_trigger_dom(const uint8_t inkey[PRESIG_MSG_LEN],
const char *domain_string, const uint8_t refkey[PRESIG_MSG_LEN]) {
uint8_t key[crypto_auth_hmacsha512_KEYBYTES];
uint8_t key_out[crypto_auth_hmacsha512_BYTES];
for (size_t serial=0; serial<PRESIG_STORE_SIZE; serial++) {
for (size_t dom=0; dom<_TRIGGER_DOMAIN_COUNT; dom++) {
static_assert(PRESIG_MSG_LEN <= crypto_auth_hmacsha512_KEYBYTES);
memcpy(key, inkey, PRESIG_MSG_LEN);
memset(key + PRESIG_MSG_LEN, 0, sizeof(key) - PRESIG_MSG_LEN);
DEBUG_PRINT("ds \"%s\"", domain_string);
debug_hexdump("ref", refkey, PRESIG_MSG_LEN);
DEBUG_PRINT("Trying domain %zd serial %zd", dom, serial);
debug_hexdump("oob_presig_iv", oob_presig_iv, sizeof(oob_presig_iv));
memcpy(buf, presig_store[dom][serial], crypto_sign_BYTES);
debug_hexdump("presig", buf, sizeof(buf));
AES_init_ctx_iv(&ctx, msg, oob_presig_iv);
AES_CBC_decrypt_buffer(&ctx, buf, crypto_sign_BYTES);
debug_hexdump("decrypted", buf, sizeof(buf));
if (!crypto_sign_verify_detached(buf, presig_messages[dom][serial], PRESIG_MSG_LEN, oob_trigger_pubkey)) {
oob_trigger_activated(dom, presig_first_serial + serial);
return 1;
}
DEBUG_PRINTN("\n");
}
for (int i=0; i<presig_height; i++) {
DEBUG_PRINT("Verifying height rel %d abs %d", i, presig_height-i);
debug_hexdump("key", key, sizeof(key));
(void)crypto_auth_hmacsha512(key_out, (uint8_t *)domain_string, strlen(domain_string), key);
debug_hexdump("out", key_out, sizeof(key_out));
memcpy(key, key_out, PRESIG_MSG_LEN);
memset(key + PRESIG_MSG_LEN, 0, sizeof(key) - PRESIG_MSG_LEN);
if (!memcmp(key, refkey, PRESIG_MSG_LEN))
return presig_height-i;
}
return 0;
}
int verify_trigger(const uint8_t inkey[PRESIG_MSG_LEN], int *height_out, int *domain_out) {
int res;
for (int i=0; i<_TRIGGER_DOMAIN_COUNT; i++) {
DEBUG_PRINT("Verifying domain %d", i);
if ((res = verify_trigger_dom(inkey, presig_domain_strings[i], presig_keys[i]))) {
DEBUG_PRINT("Match!");
if (height_out)
*height_out = res - 1;
if (domain_out)
*domain_out = i;
return 1;
}
}
return 0;
}
int oob_message_received(uint8_t msg[static OOB_TRIGGER_LEN]) {
int height, domain;
if (verify_trigger(msg, &height, &domain)) {
oob_trigger_activated(domain, height);
return 1;
}
return 0;

20
controller/fw/src/crypto.h
View file

@ -3,12 +3,8 @@
#include <stdint.h>
#include <sodium.h>
#define OOB_TRIGGER_LEN 16
#define PRESIG_MSG_LEN 16
#define OOB_TRIGGER_LEN PRESIG_MSG_LEN
enum trigger_domain {
TRIGGER_DOMAIN_ALL,
@ -19,15 +15,15 @@ enum trigger_domain {
_TRIGGER_DOMAIN_COUNT
};
extern uint8_t presig_store[_TRIGGER_DOMAIN_COUNT][PRESIG_STORE_SIZE][crypto_sign_BYTES];
extern uint8_t oob_trigger_pubkey[crypto_sign_PUBLICKEYBYTES];
extern uint8_t presig_messages[_TRIGGER_DOMAIN_COUNT][PRESIG_STORE_SIZE][PRESIG_MSG_LEN];
extern uint8_t oob_presig_iv[16];
extern int presig_first_serial;
extern const char *presig_domain_strings[_TRIGGER_DOMAIN_COUNT];
extern uint8_t presig_keys[_TRIGGER_DOMAIN_COUNT][PRESIG_MSG_LEN];
extern int presig_height;
extern uint8_t presig_bundle_id[16];
extern uint64_t bundle_timestamp;
extern void oob_trigger_activated(enum trigger_domain domain, int serial);
extern void oob_trigger_activated(enum trigger_domain domain, int height);
int oob_message_received(uint8_t msg[static OOB_TRIGGER_LEN]);
int verify_trigger(const uint8_t inkey[PRESIG_MSG_LEN], int *height_out, int *domain_out);
#endif /* __CRYPTO_H__ */