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处理Client Hello中的GREASE close #134

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This commit is contained in:
zhengchao
2019-05-25 19:12:55 +08:00
parent 7431a0e50a
commit e53f5ebcf2
2 changed files with 27 additions and 8 deletions
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3
platform/src/ssl_service_cache.cpp
View File

@@ -81,14 +81,11 @@ static size_t ssl_svc_client_st_mk_key(const struct ssl_chello* chello, char* ke
memcpy(key_buff+key_len, chello->sign_algos, chello->sign_algos_len);
key_len+=chello->sign_algos_len;
}
/*
//Temporary remove EC groups from client identifier for ssl_chello_parse cannot handling GREASE type.
if(chello->supported_groups && sz-key_len > chello->supported_groups_len)
{
memcpy(key_buff+key_len, chello->supported_groups, chello->supported_groups_len);
key_len+=chello->supported_groups_len;
}
*/
return key_len;
}
static long cli_st_read_cb(void * data, const uchar * key, uint size, void * user_arg)

32
platform/src/ssl_utils.cpp
View File

@@ -1743,6 +1743,20 @@ void ssl_chello_free(struct ssl_chello* chello)
chello->cipher_suites = NULL;
FREE(&chello);
}
static int cipher_is_grease(uint16_t cipher)
{
uint16_t a=cipher>>8;
uint16_t b=cipher&0x00ff;
//https://tools.ietf.org/html/draft-davidben-tls-grease-01#section-5
if(a==b && (a&0x0f)==0x0a)
{
return 1;
}
else
{
return 0;
}
}
static int parse_server_name_extension(const unsigned char *buff, uint16_t buff_len, struct ssl_chello* chello)
{
@@ -1863,10 +1877,18 @@ static int parse_supported_groups_extension(const unsigned char* buff, uint16_t
{
return CHELLO_PARSE_INVALID_FORMAT;
}
char *supported_groups = ALLOC(char, len);
memcpy(supported_groups, (void*)(buff + 2), len);
chello->supported_groups = supported_groups;
chello->supported_groups_len = len;
chello->supported_groups = ALLOC(char, len);
uint16_t* known_groups = (uint16_t*) chello->supported_groups;
uint16_t* raw_groups= (uint16_t*) (buff + 2);
size_t i=0, j=0;
for(i=0; i<len/2; i++)
{
if(!cipher_is_grease(raw_groups[i]))
{
known_groups[j++]=raw_groups[i];
}
}
chello->supported_groups_len = j*2;
return CHELLO_PARSE_SUCCESS;
}
@@ -2281,7 +2303,7 @@ struct ssl_chello* ssl_chello_parse(const unsigned char* buff, size_t buff_len,
for(i=0, j=0; i<len/2; i++)
{
//https://security.stackexchange.com/questions/176951/google-chrome-weird-random-cipher-suite
if(cipher_suites_convert_helper(raw_cipher[i], NULL, 0)>0)
if(!cipher_is_grease(raw_cipher[i]))
{
known_cipher[j++]=raw_cipher[i];
}