Port early callback support to CBS.

Resolve one of the TODOs since it's quick. Adjust the
-expect-server-name test to assert it both in the normal codepath and
in the early callback, to provide test coverage for
SSL_early_callback_ctx_extension_get.

Change-Id: I4d71158b9fd2f4fbb54d3e51184bd25d117bdc91
Reviewed-on: https://boringssl-review.googlesource.com/1120
Reviewed-by: Adam Langley <agl@google.com>
This commit is contained in:
David Benjamin 2014-07-09 09:30:38 -04:00 committed by Adam Langley
parent 2f1f89d6af
commit 8f2c20eb70
2 changed files with 89 additions and 83 deletions

View File

@ -296,102 +296,64 @@ done:
char ssl_early_callback_init(struct ssl_early_callback_ctx *ctx)
{
size_t len = ctx->client_hello_len;
const unsigned char *p = ctx->client_hello;
CBS extensions;
CBS client_hello, session_id, cipher_suites, compression_methods, extensions;
CBS_init(&client_hello, ctx->client_hello, ctx->client_hello_len);
/* Skip client version. */
if (len < 2)
if (!CBS_skip(&client_hello, 2))
return 0;
len -= 2; p += 2;
/* Skip client nonce. */
if (len < 32)
if (!CBS_skip(&client_hello, 32))
return 0;
len -= 32; p += 32;
/* Get length of session id. */
if (len < 1)
/* Extract session_id. */
if (!CBS_get_u8_length_prefixed(&client_hello, &session_id))
return 0;
ctx->session_id_len = *p;
p++; len--;
ctx->session_id = p;
if (len < ctx->session_id_len)
return 0;
p += ctx->session_id_len; len -= ctx->session_id_len;
ctx->session_id = CBS_data(&session_id);
ctx->session_id_len = CBS_len(&session_id);
/* Skip past DTLS cookie */
if (ctx->ssl->version == DTLS1_VERSION || ctx->ssl->version == DTLS1_BAD_VER)
{
unsigned cookie_len;
CBS cookie;
if (len < 1)
if (!CBS_get_u8_length_prefixed(&client_hello, &cookie))
return 0;
cookie_len = *p;
p++; len--;
if (len < cookie_len)
return 0;
p += cookie_len; len -= cookie_len;
}
/* Skip cipher suites. */
if (len < 2)
/* Extract cipher_suites. */
if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
CBS_len(&cipher_suites) < 2 ||
(CBS_len(&cipher_suites) & 1) != 0)
return 0;
n2s(p, ctx->cipher_suites_len);
len -= 2;
ctx->cipher_suites = CBS_data(&cipher_suites);
ctx->cipher_suites_len = CBS_len(&cipher_suites);
if ((ctx->cipher_suites_len & 1) != 0)
/* Extract compression_methods. */
if (!CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
CBS_len(&compression_methods) < 1)
return 0;
ctx->cipher_suites = p;
if (len < ctx->cipher_suites_len)
return 0;
p += ctx->cipher_suites_len; len -= ctx->cipher_suites_len;
/* Skip compression methods. */
if (len < 1)
return 0;
ctx->compression_methods_len = *p;
p++; len--;
ctx->compression_methods = p;
if (len < ctx->compression_methods_len)
return 0;
p += ctx->compression_methods_len; len -= ctx->compression_methods_len;
ctx->compression_methods = CBS_data(&compression_methods);
ctx->compression_methods_len = CBS_len(&compression_methods);
/* If the ClientHello ends here then it's valid, but doesn't have any
* extensions. (E.g. SSLv3.) */
if (len == 0)
if (CBS_len(&client_hello) == 0)
{
ctx->extensions = NULL;
ctx->extensions_len = 0;
return 1;
}
if (len < 2)
return 0;
n2s(p, ctx->extensions_len);
len -= 2;
if (ctx->extensions_len == 0 && len == 0)
{
ctx->extensions = NULL;
return 1;
}
ctx->extensions = p;
if (len != ctx->extensions_len)
return 0;
/* Verify that the extensions have valid lengths and that there are
* no duplicates.
*
* TODO(fork): Port the rest of this processing to CBS.
*/
CBS_init(&extensions, ctx->extensions, ctx->extensions_len);
if (!tls1_check_duplicate_extensions(&extensions))
/* Extract extensions and check it is valid. */
if (!CBS_get_u16_length_prefixed(&client_hello, &extensions) ||
!tls1_check_duplicate_extensions(&extensions) ||
CBS_len(&client_hello) != 0)
return 0;
ctx->extensions = CBS_data(&extensions);
ctx->extensions_len = CBS_len(&extensions);
return 1;
}
@ -402,29 +364,26 @@ SSL_early_callback_ctx_extension_get(const struct ssl_early_callback_ctx *ctx,
const unsigned char **out_data,
size_t *out_len)
{
size_t len = ctx->extensions_len;
const unsigned char *p = ctx->extensions;
CBS extensions;
while (len != 0)
CBS_init(&extensions, ctx->extensions, ctx->extensions_len);
while (CBS_len(&extensions) != 0)
{
uint16_t ext_type, ext_len;
uint16_t type;
CBS extension;
if (len < 4)
/* Decode the next extension. */
if (!CBS_get_u16(&extensions, &type) ||
!CBS_get_u16_length_prefixed(&extensions, &extension))
return 0;
n2s(p, ext_type);
n2s(p, ext_len);
len -= 4;
if (len < ext_len)
return 0;
if (ext_type == extension_type)
if (type == extension_type)
{
*out_data = p;
*out_len = ext_len;
*out_data = CBS_data(&extension);
*out_len = CBS_len(&extension);
return 1;
}
p += ext_len; len -= ext_len;
}
return 0;

View File

@ -16,10 +16,51 @@
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <openssl/ssl.h>
#include <openssl/bio.h>
#include <openssl/bytestring.h>
const char *expected_server_name = NULL;
int early_callback_called = 0;
int select_certificate_callback(const struct ssl_early_callback_ctx *ctx) {
early_callback_called = 1;
if (expected_server_name) {
const unsigned char *extension_data;
size_t extension_len;
CBS extension, server_name_list, host_name;
uint8_t name_type;
if (!SSL_early_callback_ctx_extension_get(ctx, TLSEXT_TYPE_server_name,
&extension_data,
&extension_len)) {
fprintf(stderr, "Could not find server_name extension.");
return -1;
}
CBS_init(&extension, extension_data, extension_len);
if (!CBS_get_u16_length_prefixed(&extension, &server_name_list) ||
CBS_len(&extension) != 0 ||
!CBS_get_u8(&server_name_list, &name_type) ||
name_type != TLSEXT_NAMETYPE_host_name ||
!CBS_get_u16_length_prefixed(&server_name_list, &host_name) ||
CBS_len(&server_name_list) != 0) {
fprintf(stderr, "Could not decode server_name extension.");
return -1;
}
if (CBS_len(&host_name) != strlen(expected_server_name) ||
memcmp(expected_server_name,
CBS_data(&host_name), CBS_len(&host_name)) != 0) {
fprintf(stderr, "Server name mismatch.");
}
}
return 1;
}
SSL *setup_test(int is_server) {
if (!SSL_library_init()) {
@ -44,6 +85,8 @@ SSL *setup_test(int is_server) {
goto err;
}
ssl_ctx->select_certificate_cb = select_certificate_callback;
ssl = SSL_new(ssl_ctx);
if (ssl == NULL) {
goto err;
@ -74,7 +117,6 @@ err:
int main(int argc, char **argv) {
int i, is_server, ret;
const char *expected_server_name = NULL;
if (argc < 2) {
fprintf(stderr, "Usage: %s (client|server) [flags...]\n", argv[0]);
@ -153,6 +195,11 @@ int main(int argc, char **argv) {
server_name, expected_server_name);
return 2;
}
if (!early_callback_called) {
fprintf(stderr, "early callback not called\n");
return 2;
}
}
for (;;) {