Reduce use of magic numbers

This commit is contained in:
Cameron Gutman 2022-04-21 23:31:04 -05:00
parent d74cc63038
commit 5fe7b36b40

View File

@ -53,6 +53,13 @@ static EVP_PKEY *privateKey;
const char* gs_error;
#define LEN_AS_HEX_STR(x) ((x) * 2 + 1)
#define SIZEOF_AS_HEX_STR(x) LEN_AS_HEX_STR(sizeof(x))
#define SIGNATURE_LEN 256
#define UUID_STRLEN 37
static int mkdirtree(const char* directory) {
char buffer[PATH_MAX];
char* p = buffer;
@ -162,7 +169,7 @@ static int load_cert(const char* keyDirectory) {
static int load_server_status(PSERVER_DATA server) {
uuid_t uuid;
char uuid_str[37];
char uuid_str[UUID_STRLEN];
int ret;
char url[4096];
@ -378,7 +385,7 @@ int gs_unpair(PSERVER_DATA server) {
int ret = GS_OK;
char url[4096];
uuid_t uuid;
char uuid_str[37];
char uuid_str[UUID_STRLEN];
PHTTP_DATA data = http_create_data();
if (data == NULL)
return GS_OUT_OF_MEMORY;
@ -397,7 +404,7 @@ int gs_pair(PSERVER_DATA server, char* pin) {
char* result = NULL;
char url[4096];
uuid_t uuid;
char uuid_str[37];
char uuid_str[UUID_STRLEN];
if (server->paired) {
gs_error = "Already paired";
@ -410,9 +417,9 @@ int gs_pair(PSERVER_DATA server, char* pin) {
}
unsigned char salt_data[16];
char salt_hex[33];
RAND_bytes(salt_data, 16);
bytes_to_hex(salt_data, salt_hex, 16);
char salt_hex[SIZEOF_AS_HEX_STR(salt_data)];
RAND_bytes(salt_data, sizeof(salt_data));
bytes_to_hex(salt_data, salt_hex, sizeof(salt_data));
uuid_generate_random(uuid);
uuid_unparse(uuid, uuid_str);
@ -439,35 +446,36 @@ int gs_pair(PSERVER_DATA server, char* pin) {
if ((ret = xml_search(data->memory, data->size, "plaincert", &result)) != GS_OK)
goto cleanup;
if (strlen(result)/2 > 8191) {
char plaincert[8192];
if (strlen(result)/2 > sizeof(plaincert) - 1) {
gs_error = "Server certificate too big";
ret = GS_FAILED;
goto cleanup;
}
char plaincert[8192];
for (int count = 0; count < strlen(result); count += 2) {
sscanf(&result[count], "%2hhx", &plaincert[count / 2]);
}
plaincert[strlen(result)/2] = '\0';
unsigned char salt_pin[20];
unsigned char aes_key[32];
memcpy(salt_pin, salt_data, 16);
memcpy(salt_pin+16, pin, 4);
unsigned char salt_pin[sizeof(salt_data) + 4];
unsigned char aes_key[32]; // Must fit SHA256
memcpy(salt_pin, salt_data, sizeof(salt_data));
memcpy(salt_pin+sizeof(salt_data), pin, 4);
int hash_length = server->serverMajorVersion >= 7 ? 32 : 20;
if (server->serverMajorVersion >= 7)
SHA256(salt_pin, 20, aes_key);
SHA256(salt_pin, sizeof(salt_pin), aes_key);
else
SHA1(salt_pin, 20, aes_key);
SHA1(salt_pin, sizeof(salt_pin), aes_key);
unsigned char challenge_data[16];
unsigned char challenge_enc[16];
char challenge_hex[33];
RAND_bytes(challenge_data, 16);
encrypt(challenge_data, 16, aes_key, challenge_enc);
bytes_to_hex(challenge_enc, challenge_hex, 16);
unsigned char challenge_enc[sizeof(challenge_data)];
char challenge_hex[SIZEOF_AS_HEX_STR(challenge_enc)];
RAND_bytes(challenge_data, sizeof(challenge_data));
encrypt(challenge_data, sizeof(challenge_data), aes_key, challenge_enc);
bytes_to_hex(challenge_enc, challenge_hex, sizeof(challenge_enc));
uuid_generate_random(uuid);
uuid_unparse(uuid, uuid_str);
@ -496,9 +504,9 @@ int gs_pair(PSERVER_DATA server, char* pin) {
}
char challenge_response_data_enc[64];
char challenge_response_data[64];
char challenge_response_data[sizeof(challenge_response_data_enc)];
if (strlen(result) / 2 > 64) {
if (strlen(result) / 2 > sizeof(challenge_response_data_enc)) {
gs_error = "Server challenge response too big";
ret = GS_FAILED;
goto cleanup;
@ -508,28 +516,28 @@ int gs_pair(PSERVER_DATA server, char* pin) {
sscanf(&result[count], "%2hhx", &challenge_response_data_enc[count / 2]);
}
decrypt(challenge_response_data_enc, 64, aes_key, challenge_response_data);
decrypt(challenge_response_data_enc, sizeof(challenge_response_data_enc), aes_key, challenge_response_data);
char client_secret_data[16];
RAND_bytes(client_secret_data, 16);
RAND_bytes(client_secret_data, sizeof(client_secret_data));
const ASN1_BIT_STRING *asnSignature;
X509_get0_signature(&asnSignature, NULL, cert);
char challenge_response[16 + 256 + 16];
char challenge_response[16 + SIGNATURE_LEN + sizeof(client_secret_data)];
char challenge_response_hash[32];
char challenge_response_hash_enc[32];
char challenge_response_hex[65];
char challenge_response_hash_enc[sizeof(challenge_response_hash)];
char challenge_response_hex[SIZEOF_AS_HEX_STR(challenge_response_hash_enc)];
memcpy(challenge_response, challenge_response_data + hash_length, 16);
memcpy(challenge_response + 16, asnSignature->data, 256);
memcpy(challenge_response + 16 + 256, client_secret_data, 16);
memcpy(challenge_response + 16, asnSignature->data, asnSignature->length);
memcpy(challenge_response + 16 + asnSignature->length, client_secret_data, sizeof(client_secret_data));
if (server->serverMajorVersion >= 7)
SHA256(challenge_response, 16 + 256 + 16, challenge_response_hash);
SHA256(challenge_response, 16 + asnSignature->length + sizeof(client_secret_data), challenge_response_hash);
else
SHA1(challenge_response, 16 + 256 + 16, challenge_response_hash);
SHA1(challenge_response, 16 + asnSignature->length + sizeof(client_secret_data), challenge_response_hash);
encrypt(challenge_response_hash, 32, aes_key, challenge_response_hash_enc);
bytes_to_hex(challenge_response_hash_enc, challenge_response_hex, 32);
encrypt(challenge_response_hash, sizeof(challenge_response_hash), aes_key, challenge_response_hash_enc);
bytes_to_hex(challenge_response_hash_enc, challenge_response_hex, sizeof(challenge_response_hash_enc));
uuid_generate_random(uuid);
uuid_unparse(uuid, uuid_str);
@ -557,12 +565,19 @@ int gs_pair(PSERVER_DATA server, char* pin) {
goto cleanup;
}
char pairing_secret[16 + 256];
char pairing_secret[16 + SIGNATURE_LEN];
if (strlen(result) / 2 > sizeof(pairing_secret)) {
gs_error = "Pairing secret too big";
ret = GS_FAILED;
goto cleanup;
}
for (int count = 0; count < strlen(result); count += 2) {
sscanf(&result[count], "%2hhx", &pairing_secret[count / 2]);
}
if (!verifySignature(pairing_secret, 16, pairing_secret+16, 256, plaincert)) {
if (!verifySignature(pairing_secret, 16, pairing_secret+16, SIGNATURE_LEN, plaincert)) {
gs_error = "MITM attack detected";
ret = GS_FAILED;
goto cleanup;
@ -570,17 +585,17 @@ int gs_pair(PSERVER_DATA server, char* pin) {
unsigned char *signature = NULL;
size_t s_len;
if (sign_it(client_secret_data, 16, &signature, &s_len, privateKey) != GS_OK) {
if (sign_it(client_secret_data, sizeof(client_secret_data), &signature, &s_len, privateKey) != GS_OK) {
gs_error = "Failed to sign data";
ret = GS_FAILED;
goto cleanup;
}
char client_pairing_secret[16 + 256];
char client_pairing_secret_hex[(16 + 256) * 2 + 1];
memcpy(client_pairing_secret, client_secret_data, 16);
memcpy(client_pairing_secret + 16, signature, 256);
bytes_to_hex(client_pairing_secret, client_pairing_secret_hex, 16 + 256);
char client_pairing_secret[sizeof(client_secret_data) + SIGNATURE_LEN];
char client_pairing_secret_hex[SIZEOF_AS_HEX_STR(client_pairing_secret)];
memcpy(client_pairing_secret, client_secret_data, sizeof(client_secret_data));
memcpy(client_pairing_secret + sizeof(client_secret_data), signature, SIGNATURE_LEN);
bytes_to_hex(client_pairing_secret, client_pairing_secret_hex, sizeof(client_secret_data) + SIGNATURE_LEN);
uuid_generate_random(uuid);
uuid_unparse(uuid, uuid_str);
@ -638,7 +653,7 @@ int gs_applist(PSERVER_DATA server, PAPP_LIST *list) {
int ret = GS_OK;
char url[4096];
uuid_t uuid;
char uuid_str[37];
char uuid_str[UUID_STRLEN];
PHTTP_DATA data = http_create_data();
if (data == NULL)
return GS_OUT_OF_MEMORY;
@ -661,7 +676,7 @@ int gs_start_app(PSERVER_DATA server, STREAM_CONFIGURATION *config, int appId, b
int ret = GS_OK;
uuid_t uuid;
char* result = NULL;
char uuid_str[37];
char uuid_str[UUID_STRLEN];
PDISPLAY_MODE mode = server->modes;
bool correct_mode = false;
@ -682,18 +697,16 @@ int gs_start_app(PSERVER_DATA server, STREAM_CONFIGURATION *config, int appId, b
if (config->height >= 2160 && !server->supports4K)
return GS_NOT_SUPPORTED_4K;
RAND_bytes(config->remoteInputAesKey, 16);
memset(config->remoteInputAesIv, 0, 16);
// GFE somehow doesn't like this totally legit random number, so we have to generate one
RAND_bytes(config->remoteInputAesIv, 4);
RAND_bytes(config->remoteInputAesKey, sizeof(config->remoteInputAesKey));
memset(config->remoteInputAesIv, 0, sizeof(config->remoteInputAesIv));
srand(time(NULL));
char url[4096];
u_int32_t rikeyid = 0;
memcpy(&rikeyid, config->remoteInputAesIv, 4);
RAND_bytes(config->remoteInputAesIv, sizeof(rikeyid));
memcpy(&rikeyid, config->remoteInputAesIv, sizeof(rikeyid));
rikeyid = htonl(rikeyid);
char rikey_hex[33];
bytes_to_hex(config->remoteInputAesKey, rikey_hex, 16);
char rikey_hex[SIZEOF_AS_HEX_STR(config->remoteInputAesKey)];
bytes_to_hex(config->remoteInputAesKey, rikey_hex, sizeof(config->remoteInputAesKey));
PHTTP_DATA data = http_create_data();
if (data == NULL)
@ -747,7 +760,7 @@ int gs_quit_app(PSERVER_DATA server) {
int ret = GS_OK;
char url[4096];
uuid_t uuid;
char uuid_str[37];
char uuid_str[UUID_STRLEN];
char* result = NULL;
PHTTP_DATA data = http_create_data();
if (data == NULL)