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Test logging TLSv1.3 secrets.
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@Lukasa
Lukasa committed Feb 1, 2017
1 parent 706d2c0 commit b64db11
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Showing 2 changed files with 135 additions and 30 deletions.
157 changes: 127 additions & 30 deletions test/sslapitest.c
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,19 @@ static X509 *ocspcert = NULL;

#define NUM_EXTRA_CERTS 40

/*
* This structure is used to validate that the correct number of log messages
* of various types are emitted when emitting secret logs.
*/
struct sslapitest_log_counts {
unsigned int rsa_key_exchange_count;
unsigned int master_secret_count;
unsigned int client_handshake_secret_count;
unsigned int server_handshake_secret_count;
unsigned int client_application_secret_count;
unsigned int server_application_secret_count;
};

static void client_keylog_callback(const SSL *ssl, const char *line) {
int line_length = strlen(line);

Expand Down Expand Up @@ -105,100 +118,171 @@ static int compare_hex_encoded_buffer(const char *hex_encoded,
}

static int test_keylog_output(char *buffer, const SSL *ssl,
const SSL_SESSION *session) {
int saw_client_random = 0;
const SSL_SESSION *session,
struct sslapitest_log_counts *expected) {
char *token = NULL;
unsigned char actual_client_random[SSL3_RANDOM_SIZE] = {0};
size_t client_random_size = SSL3_RANDOM_SIZE;
unsigned char actual_master_key[SSL_MAX_MASTER_KEY_LENGTH] = {0};
size_t master_key_size = SSL_MAX_MASTER_KEY_LENGTH;
unsigned int rsa_key_exchange_count = 0;
unsigned int master_secret_count = 0;
unsigned int client_handshake_secret_count = 0;
unsigned int server_handshake_secret_count = 0;
unsigned int client_application_secret_count = 0;
unsigned int server_application_secret_count = 0;

token = strtok(buffer, " \n");
while (token) {
if (strcmp(token, "RSA") == 0) {
/* Premaster secret. Tokens should be: 16 ASCII bytes of
/*
* Premaster secret. Tokens should be: 16 ASCII bytes of
* hex-encoded encrypted secret, then the hex-encoded pre-master
* secret.
*/
token = strtok(NULL, " \n");
if (!token) {
printf("Unexpectedly short premaster secret log.\n");
return -1;
return 0;
}
if (strlen(token) != 16) {
printf("Bad value for encrypted secret: %s\n", token);
return -1;
return 0;
}
token = strtok(NULL, " \n");
if (!token) {
printf("Unexpectedly short premaster secret log.\n");
return -1;
return 0;
}
/* TODO: Can I check this sensibly? */
/*
* We can't sensibly check the log because the premaster secret is
* transient, and OpenSSL doesn't keep hold of it once the master
* secret is generated.
*/
rsa_key_exchange_count++;
} else if (strcmp(token, "CLIENT_RANDOM") == 0) {
/* Master secret. Tokens should be: 64 ASCII bytes of hex-encoded
/*
* Master secret. Tokens should be: 64 ASCII bytes of hex-encoded
* client random, then the hex-encoded master secret.
*/
client_random_size = SSL_get_client_random(ssl,
actual_client_random,
SSL3_RANDOM_SIZE);
if (client_random_size != SSL3_RANDOM_SIZE) {
printf("Unexpected short client random.\n");
return -1;
return 0;
}

token = strtok(NULL, " \n");
if (!token) {
printf("Unexpected short master secret log.\n");
return -1;
return 0;
}
if (strlen(token) != 64) {
printf("Bad value for client random: %s\n", token);
return -1;
return 0;
}
if (compare_hex_encoded_buffer(token, 64, actual_client_random,
client_random_size)) {
printf("Bad value for client random: %s\n", token);
return -1;
return 0;
}

token = strtok(NULL, " \n");
if (!token) {
printf("Unexpectedly short master secret log.\n");
return -1;
return 0;
}

master_key_size = SSL_SESSION_get_master_key(session,
actual_master_key,
master_key_size);
if (!master_key_size) {
printf("Error getting master key to compare.\n");
return -1;
return 0;
}
if (compare_hex_encoded_buffer(token, strlen(token),
actual_master_key,
master_key_size)) {
printf("Bad value for master key: %s\n", token);
return -1;
return 0;
}

saw_client_random = 1;
master_secret_count++;
} else if ((strcmp(token, "CLIENT_HANDSHAKE_TRAFFIC_SECRET") == 0) ||
(strcmp(token, "SERVER_HANDSHAKE_TRAFFIC_SECRET") == 0) ||
(strcmp(token, "CLIENT_TRAFFIC_SECRET_0") == 0) ||
(strcmp(token, "SERVER_TRAFFIC_SECRET_0") == 0)) {
/*
* TLSv1.3 secret. Tokens should be: 64 ASCII bytes of hex-encoded
* client random, and then the hex-encoded secret. In this case,
* we treat all of these secrets identically and then just
* distinguish between them when counting what we saw.
*/
if (strcmp(token, "CLIENT_HANDSHAKE_TRAFFIC_SECRET") == 0)
client_handshake_secret_count++;
else if (strcmp(token, "SERVER_HANDSHAKE_TRAFFIC_SECRET") == 0)
server_handshake_secret_count++;
else if (strcmp(token, "CLIENT_TRAFFIC_SECRET_0") == 0)
client_application_secret_count++;
else if (strcmp(token, "SERVER_TRAFFIC_SECRET_0") == 0)
server_application_secret_count++;

client_random_size = SSL_get_client_random(ssl,
actual_client_random,
SSL3_RANDOM_SIZE);
if (client_random_size != SSL3_RANDOM_SIZE) {
printf("Unexpected short client random.\n");
return 0;
}

token = strtok(NULL, " \n");
if (!token) {
printf("Unexpected short client handshake secret log.\n");
return 0;
}
if (strlen(token) != 64) {
printf("Bad value for client random: %s\n", token);
return 0;
}
if (compare_hex_encoded_buffer(token, 64, actual_client_random,
client_random_size)) {
printf("Bad value for client random: %s\n", token);
return 0;
}

token = strtok(NULL, " \n");
if (!token) {
printf("Unexpectedly short master secret log.\n");
return 0;
}

/*
* TODO(TLS1.3): test that application traffic secrets are what
* we expect */
} else {
printf("Unexpected token in buffer: %s\n", token);
return -1;
return 0;
}

token = strtok(NULL, " \n");
}

return saw_client_random;
/* Return whether we got what we expected. */
return ((rsa_key_exchange_count == expected->rsa_key_exchange_count) &&
(master_secret_count == expected->master_secret_count) &&
(client_handshake_secret_count == expected->client_handshake_secret_count) &&
(server_handshake_secret_count == expected->server_handshake_secret_count) &&
(client_application_secret_count == expected->client_application_secret_count) &&
(server_application_secret_count == expected->server_application_secret_count));
}

static int test_keylog(void) {
SSL_CTX *cctx = NULL, *sctx = NULL;
SSL *clientssl = NULL, *serverssl = NULL;
int testresult = 0;
int rc;
struct sslapitest_log_counts expected = {0};

/* Clean up logging space */
memset(client_log_buffer, 0, LOG_BUFFER_SIZE + 1);
Expand Down Expand Up @@ -269,17 +353,23 @@ static int test_keylog(void) {
goto end;
}

/* Now we want to test that our output data was vaguely sensible. We
/*
* Now we want to test that our output data was vaguely sensible. We
* do that by using strtok and confirming that we have more or less the
* data we expect.
* data we expect. For both client and server, we expect to see one master
* secret. The client should also see a RSA key exchange.
*/
if (test_keylog_output(client_log_buffer, clientssl,
SSL_get_session(clientssl)) != 1) {
expected.rsa_key_exchange_count = 1;
expected.master_secret_count = 1;
if (!test_keylog_output(client_log_buffer, clientssl,
SSL_get_session(clientssl), &expected)) {
printf("Error encountered in client log buffer\n");
goto end;
}
if (test_keylog_output(server_log_buffer, serverssl,
SSL_get_session(serverssl)) != 1) {

expected.rsa_key_exchange_count = 0;
if (!test_keylog_output(server_log_buffer, serverssl,
SSL_get_session(serverssl), &expected)) {
printf("Error encountered in server log buffer\n");
goto end;
}
Expand All @@ -300,6 +390,7 @@ static int test_keylog_no_master_key(void) {
SSL_CTX *cctx = NULL, *sctx = NULL;
SSL *clientssl = NULL, *serverssl = NULL;
int testresult = 0;
struct sslapitest_log_counts expected = {0};

/* Clean up logging space */
memset(client_log_buffer, 0, LOG_BUFFER_SIZE + 1);
Expand Down Expand Up @@ -354,16 +445,22 @@ static int test_keylog_no_master_key(void) {
goto end;
}

/* Now we want to test that our output data was vaguely sensible. For this
* test, we expect no CLIENT_RANDOM entry.
/*
* Now we want to test that our output data was vaguely sensible. For this
* test, we expect no CLIENT_RANDOM entry becuase it doesn't make sense for
* TLSv1.3, but we do expect both client and server to emit keys.
*/
if (test_keylog_output(client_log_buffer, clientssl,
SSL_get_session(clientssl)) != 0) {
expected.client_handshake_secret_count = 1;
expected.server_handshake_secret_count = 1;
expected.client_application_secret_count = 1;
expected.server_application_secret_count = 1;
if (!test_keylog_output(client_log_buffer, clientssl,
SSL_get_session(clientssl), &expected)) {
printf("Error encountered in client log buffer\n");
goto end;
}
if (test_keylog_output(server_log_buffer, serverssl,
SSL_get_session(serverssl)) != 0) {
if (!test_keylog_output(server_log_buffer, serverssl,
SSL_get_session(serverssl), &expected)) {
printf("Error encountered in server log buffer\n");
goto end;
}
Expand Down
8 changes: 8 additions & 0 deletions test/tls13secretstest.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -184,6 +184,14 @@ int tls1_alert_code(int code)
return code;
}

int ssl_log_secret(SSL *ssl,
const char *label,
const uint8_t *secret,
size_t secret_len)
{
return 1;
}

/* End of mocked out code */

static int test_secret(SSL *s, unsigned char *prk,
Expand Down

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