Merge pull request #16 from mathewmarcus/tls_extensions

Tls extensions
This commit is contained in:
Alexandre Dulaunoy 2018-06-30 21:53:55 +02:00 committed by GitHub
commit c36c411547
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
6 changed files with 426 additions and 46 deletions

View file

@ -6,6 +6,8 @@
#include <openssl/ssl.h> #include <openssl/ssl.h>
#endif #endif
#include "ssl.enums.h" #include "ssl.enums.h"
static int decode_extension(ssl,dir,seg,data);
static int decode_server_name(ssl,dir,seg,data);
static int decode_ContentType_ChangeCipherSpec(ssl,dir,seg,data) static int decode_ContentType_ChangeCipherSpec(ssl,dir,seg,data)
ssl_obj *ssl; ssl_obj *ssl;
int dir; int dir;
@ -174,14 +176,16 @@ static int decode_HandshakeType_ClientHello(ssl,dir,seg,data)
{ {
UINT4 vj,vn,cs,cslen,complen,comp,odd; UINT4 vj,vn,cs,cslen,complen,comp,odd,exlen,ex;
Data session_id,random; Data session_id,random;
int r; int r;
extern decoder cipher_suite_decoder[]; extern decoder cipher_suite_decoder[];
extern decoder compression_method_decoder[]; extern decoder compression_method_decoder[];
extern decoder extension_decoder[];
printf("\n"); printf("\n");
ssl_update_handshake_messages(ssl,data);
SSL_DECODE_UINT8(ssl,0,0,data,&vj); SSL_DECODE_UINT8(ssl,0,0,data,&vj);
SSL_DECODE_UINT8(ssl,0,0,data,&vn); SSL_DECODE_UINT8(ssl,0,0,data,&vn);
@ -226,6 +230,22 @@ static int decode_HandshakeType_ClientHello(ssl,dir,seg,data)
printf("\n"); printf("\n");
} }
} }
SSL_DECODE_UINT16(ssl,"extensions len",0,data,&exlen);
if (exlen) {
explain(ssl , "extensions\n");
while(data->len) {
SSL_DECODE_UINT16(ssl, "extension type", 0, data, &ex);
if (ssl_decode_switch(ssl,extension_decoder,ex,dir,seg,data) == R_NOT_FOUND) {
decode_extension(ssl,dir,seg,data);
P_(P_RH){
explain(ssl, "Extension type: %s not yet implemented in ssldump", ex);
}
continue;
}
printf("\n");
}
}
return(0); return(0);
} }
@ -236,11 +256,14 @@ static int decode_HandshakeType_ServerHello(ssl,dir,seg,data)
Data *data; Data *data;
{ {
int r; int r;
Data rnd,session_id; Data rnd,session_id;
UINT4 vj,vn; UINT4 vj,vn,exlen,ex;
extern decoder extension_decoder[];
printf("\n"); printf("\n");
ssl_update_handshake_messages(ssl,data);
SSL_DECODE_UINT8(ssl,0,0,data,&vj); SSL_DECODE_UINT8(ssl,0,0,data,&vj);
SSL_DECODE_UINT8(ssl,0,0,data,&vn); SSL_DECODE_UINT8(ssl,0,0,data,&vn);
@ -267,6 +290,23 @@ static int decode_HandshakeType_ServerHello(ssl,dir,seg,data)
P_(P_HL) printf("\n"); P_(P_HL) printf("\n");
SSL_DECODE_ENUM(ssl,"compressionMethod",1,compression_method_decoder,P_HL,data,0); SSL_DECODE_ENUM(ssl,"compressionMethod",1,compression_method_decoder,P_HL,data,0);
P_(P_HL) printf("\n"); P_(P_HL) printf("\n");
SSL_DECODE_UINT16(ssl,"extensions len",0,data,&exlen);
if (exlen) {
explain(ssl , "extensions\n");
while(data->len) {
SSL_DECODE_UINT16(ssl, "extension type", 0, data, &ex);
if (ssl_decode_switch(ssl,extension_decoder,ex,dir,seg,data) == R_NOT_FOUND) {
decode_extension(ssl,dir,seg,data);
P_(P_RH){
explain(ssl, "Extension type: %s not yet implemented in ssldump", ex);
}
continue;
}
printf("\n");
}
}
return(0); return(0);
} }
@ -283,6 +323,7 @@ static int decode_HandshakeType_Certificate(ssl,dir,seg,data)
int r; int r;
printf("\n"); printf("\n");
ssl_update_handshake_messages(ssl,data);
SSL_DECODE_UINT24(ssl,"certificates len",0,data,&len); SSL_DECODE_UINT24(ssl,"certificates len",0,data,&len);
while(len){ while(len){
@ -306,7 +347,7 @@ static int decode_HandshakeType_ServerKeyExchange(ssl,dir,seg,data)
int r; int r;
printf("\n"); printf("\n");
ssl_update_handshake_messages(ssl,data);
if(ssl->cs){ if(ssl->cs){
P_(P_ND){ P_(P_ND){
explain(ssl,"params\n"); explain(ssl,"params\n");
@ -344,6 +385,7 @@ static int decode_HandshakeType_CertificateRequest(ssl,dir,seg,data)
int r; int r;
printf("\n"); printf("\n");
ssl_update_handshake_messages(ssl,data);
SSL_DECODE_UINT8(ssl,"certificate_types len",0,data,&len); SSL_DECODE_UINT8(ssl,"certificate_types len",0,data,&len);
for(;len;len--){ for(;len;len--){
SSL_DECODE_ENUM(ssl,"certificate_types",1, SSL_DECODE_ENUM(ssl,"certificate_types",1,
@ -375,6 +417,7 @@ static int decode_HandshakeType_ServerHelloDone(ssl,dir,seg,data)
printf("\n"); printf("\n");
ssl_update_handshake_messages(ssl,data);
return(0); return(0);
} }
@ -388,6 +431,7 @@ static int decode_HandshakeType_CertificateVerify(ssl,dir,seg,data)
int r; int r;
printf("\n"); printf("\n");
ssl_update_handshake_messages(ssl,data);
SSL_DECODE_OPAQUE_ARRAY(ssl,"Signature",-(1<<15-1),P_HL,data,0); SSL_DECODE_OPAQUE_ARRAY(ssl,"Signature",-(1<<15-1),P_HL,data,0);
return(0); return(0);
@ -404,6 +448,7 @@ static int decode_HandshakeType_ClientKeyExchange(ssl,dir,seg,data)
Data pms; Data pms;
printf("\n"); printf("\n");
ssl_update_handshake_messages(ssl,data);
if(ssl->cs){ if(ssl->cs){
switch(ssl->cs->kex){ switch(ssl->cs->kex){
@ -2403,3 +2448,184 @@ decoder client_certificate_type_decoder[]={
{-1} {-1}
}; };
static int decode_extension_server_name(ssl,dir,seg,data)
ssl_obj *ssl;
int dir;
segment *seg;
Data *data;
{
UINT4 t;
int l,r,p;
extern decoder server_name_type_decoder[];
SSL_DECODE_UINT16(ssl,"extension length",0,data,&l);
if(dir==DIR_I2R){
SSL_DECODE_UINT16(ssl,"server name list length",0,data,&l);
printf("\n");
while(l) {
p=data->len;
SSL_DECODE_UINT8(ssl, "server name type", 0, data, &t);
if (ssl_decode_switch(ssl,server_name_type_decoder,t,dir,seg,data) == R_NOT_FOUND) {
decode_server_name(ssl,dir,seg,data);
P_(P_RH){
explain(ssl, "Server Name type: %s not yet implemented in ssldump", t);
}
continue;
}
l-=(p-data->len);
}
}
else{
data->len-=l;
data->data+=l;
}
return(0);
}
static int decode_extension_encrypt_then_mac(ssl,dir,seg,data)
ssl_obj *ssl;
int dir;
segment *seg;
Data *data;
{
int l,r,*etm;
etm=&ssl->extensions->encrypt_then_mac;
SSL_DECODE_UINT16(ssl,"extension length",0,data,&l);
data->len-=l;
data->data+=l;
*etm=dir==DIR_I2R?1:*etm==1;
return(0);
}
static int decode_extension_extended_master_secret(ssl,dir,seg,data)
ssl_obj *ssl;
int dir;
segment *seg;
Data *data;
{
int l,r,*ems;
ems=&ssl->extensions->extended_master_secret;
SSL_DECODE_UINT16(ssl,"extension length",0,data,&l);
data->len-=l;
data->data+=l;
*ems=dir==DIR_I2R?1:*ems==1;
return(0);
}
static int decode_extension(ssl,dir,seg,data)
ssl_obj *ssl;
int dir;
segment *seg;
Data *data;
{
int l,r;
SSL_DECODE_UINT16(ssl,"extension length",0,data,&l);
data->len-=l;
data->data+=l;
return(0);
}
decoder extension_decoder[] = {
{
0,
"server_name",
decode_extension_server_name,
},
{
1,
"max_fragment_length",
decode_extension
},
{
2,
"client_certificate_url",
decode_extension
},
{
3,
"trusted_ca_keys",
decode_extension
},
{
4,
"truncated_hmac",
decode_extension
},
{
5,
"status_request",
decode_extension
},
{
13,
"signature_algorithms",
decode_extension
},
{
16,
"application_layer_protocol_negotiation",
decode_extension
},
{
22,
"encrypt_then_mac",
decode_extension_encrypt_then_mac
},
{
23,
"extended_master_secret",
decode_extension_extended_master_secret
},
{
13172,
"next_protocol_negotiation",
decode_extension
},
{-1}
};
static int decode_server_name_type_host_name(ssl,dir,seg,data)
ssl_obj *ssl;
int dir;
segment *seg;
Data *data;
{
int l,r;
SSL_DECODE_UINT16(ssl,"server name length",0,data,&l);
printf(": %.*s",l,data->data);
/* Possibly use data->data to set/modify ssl->server_name */
data->len-=l;
data->data+=l;
return(0);
}
static int decode_server_name(ssl,dir,seg,data)
ssl_obj *ssl;
int dir;
segment *seg;
Data *data;
{
int l,r;
SSL_DECODE_UINT16(ssl,"server name length",0,data,&l);
data->len-=l;
data->data+=l;
return(0);
}
decoder server_name_type_decoder[]={
{
0,
"host_name",
decode_server_name_type_host_name
},
{-1}
};

View file

@ -266,6 +266,9 @@ static int create_ssl_analyzer(handle,ctx,conn,objp,i_addr,i_port,r_addr,r_port,
if(r=ssl_decoder_create(&obj->decoder,obj->ssl_ctx)) if(r=ssl_decoder_create(&obj->decoder,obj->ssl_ctx))
ABORT(r); ABORT(r);
if (!(obj->extensions=malloc(sizeof(ssl_extensions))))
ABORT(R_NO_MEMORY);
*objp=(proto_obj *)obj; *objp=(proto_obj *)obj;
_status=0; _status=0;
@ -292,6 +295,7 @@ static int destroy_ssl_analyzer(objp)
ssl_decoder_destroy(&obj->decoder); ssl_decoder_destroy(&obj->decoder);
free(obj->client_name); free(obj->client_name);
free(obj->server_name); free(obj->server_name);
free(obj->extensions);
free(*objp); free(*objp);
*objp=0; *objp=0;

View file

@ -67,6 +67,11 @@ typedef struct d_queue_ {
int offset; /*How far into the first segment this record starts*/ int offset; /*How far into the first segment this record starts*/
} r_queue; } r_queue;
typedef struct ssl_extensions_ {
int encrypt_then_mac;
int extended_master_secret;
} ssl_extensions;
typedef struct ssl_obj_ { typedef struct ssl_obj_ {
tcp_conn *conn; tcp_conn *conn;
int r_state; int r_state;
@ -86,6 +91,7 @@ typedef struct ssl_obj_ {
struct timeval time_last; struct timeval time_last;
ssl_decode_ctx *ssl_ctx; ssl_decode_ctx *ssl_ctx;
ssl_decoder *decoder; ssl_decoder *decoder;
ssl_extensions *extensions;
int process_ciphertext; int process_ciphertext;

View file

@ -94,7 +94,7 @@ char *ciphers[]={
static int tls_check_mac PROTO_LIST((ssl_rec_decoder *d,int ct, static int tls_check_mac PROTO_LIST((ssl_rec_decoder *d,int ct,
int ver,UCHAR *data,UINT4 datalen,UCHAR *mac)); int ver,UCHAR *data,UINT4 datalen,UCHAR *iv,UINT4 ivlen,UCHAR *mac));
static int fmt_seq PROTO_LIST((UINT4 num,UCHAR *buf)); static int fmt_seq PROTO_LIST((UINT4 num,UCHAR *buf));
int ssl_create_rec_decoder(dp,cs,mk,sk,iv) int ssl_create_rec_decoder(dp,cs,mk,sk,iv)
@ -162,6 +162,7 @@ int ssl_destroy_rec_decoder(dp)
return(0); return(0);
} }
int ssl_decode_rec_data(ssl,d,ct,version,in,inl,out,outl) int ssl_decode_rec_data(ssl,d,ct,version,in,inl,out,outl)
ssl_obj *ssl; ssl_obj *ssl;
ssl_rec_decoder *d; ssl_rec_decoder *d;
@ -174,10 +175,51 @@ int ssl_decode_rec_data(ssl,d,ct,version,in,inl,out,outl)
{ {
#ifdef OPENSSL #ifdef OPENSSL
int pad; int pad;
int r; int r,encpadl;
UCHAR *mac; UCHAR *mac,*iv;
CRDUMP("Ciphertext",in,inl); CRDUMP("Ciphertext",in,inl);
if(ssl->extensions->encrypt_then_mac){
*outl=inl;
/* First strip off the MAC */
*outl-=d->cs->dig_len;
mac=in+(*outl);
encpadl=*outl;
/* Now decrypt */
EVP_Cipher(d->evp,out,in,*outl);
CRDUMP("Plaintext",out,*outl);
/* And then strip off the padding*/
if(d->cs->block>1){
pad=out[*outl-1];
*outl-=(pad+1);
}
/* TLS 1.1 and beyond: remove explicit IV, only used with
* non-stream ciphers. */
if (ssl->version>=0x0302 && ssl->cs->block > 1) {
UINT4 blk = ssl->cs->block;
if (blk <= *outl) {
*outl-=blk;
memmove(out, out+blk, *outl);
}
else {
DBG((0,"Block size greater than Plaintext!"));
ERETURN(SSL_BAD_MAC);
}
if(r=tls_check_mac(d,ct,version,in+blk,encpadl,in,blk,mac))
ERETURN(r);
}
else
if(r=tls_check_mac(d,ct,version,in,encpadl,NULL,0,mac))
ERETURN(r);
}
else {
/* First decrypt*/ /* First decrypt*/
EVP_Cipher(d->evp,out,in,inl); EVP_Cipher(d->evp,out,in,inl);
@ -214,10 +256,10 @@ int ssl_decode_rec_data(ssl,d,ct,version,in,inl,out,outl)
ERETURN(SSL_BAD_MAC); ERETURN(SSL_BAD_MAC);
} }
} }
if(r=tls_check_mac(d,ct,version,out,*outl,mac)) if(r=tls_check_mac(d,ct,version,out,*outl,NULL,0,mac))
ERETURN(r); ERETURN(r);
} }
}
#endif #endif
return(0); return(0);
} }
@ -242,12 +284,14 @@ static int fmt_seq(num,buf)
return(0); return(0);
} }
static int tls_check_mac(d,ct,ver,data,datalen,mac) static int tls_check_mac(d,ct,ver,data,datalen,iv,ivlen,mac)
ssl_rec_decoder *d; ssl_rec_decoder *d;
int ct; int ct;
int ver; int ver;
UCHAR *data; UCHAR *data;
UINT4 datalen; UINT4 datalen;
UCHAR *iv;
UINT4 ivlen;
UCHAR *mac; UCHAR *mac;
{ {
HMAC_CTX hm; HMAC_CTX hm;
@ -272,6 +316,12 @@ static int tls_check_mac(d,ct,ver,data,datalen,mac)
buf[1]=LSB(datalen); buf[1]=LSB(datalen);
HMAC_Update(&hm,buf,2); HMAC_Update(&hm,buf,2);
/* for encrypt-then-mac with an explicit IV */
if(ivlen && iv){
HMAC_Update(&hm,iv,ivlen);
HMAC_Update(&hm,data,datalen-ivlen);
}
else
HMAC_Update(&hm,data,datalen); HMAC_Update(&hm,data,datalen);
HMAC_Final(&hm,buf,&l); HMAC_Final(&hm,buf,&l);

View file

@ -91,6 +91,8 @@ struct ssl_decoder_ {
int ephemeral_rsa; int ephemeral_rsa;
Data *PMS; Data *PMS;
Data *MS; Data *MS;
Data *handshake_messages;
Data *session_hash;
ssl_rec_decoder *c_to_s; ssl_rec_decoder *c_to_s;
ssl_rec_decoder *s_to_c; ssl_rec_decoder *s_to_c;
ssl_rec_decoder *c_to_s_n; ssl_rec_decoder *c_to_s_n;
@ -111,6 +113,8 @@ static int ssl3_generate_export_iv PROTO_LIST((ssl_obj *ssl,
Data *rnd1,Data *rnd2,Data *out)); Data *rnd1,Data *rnd2,Data *out));
static int ssl_generate_keying_material PROTO_LIST((ssl_obj *ssl, static int ssl_generate_keying_material PROTO_LIST((ssl_obj *ssl,
ssl_decoder *d)); ssl_decoder *d));
static int ssl_generate_session_hash PROTO_LIST((ssl_obj *ssl,
ssl_decoder *d));
#endif #endif
static int ssl_create_session_lookup_key PROTO_LIST((ssl_obj *ssl, static int ssl_create_session_lookup_key PROTO_LIST((ssl_obj *ssl,
@ -214,6 +218,8 @@ int ssl_decoder_destroy(dp)
r_data_destroy(&d->session_id); r_data_destroy(&d->session_id);
r_data_destroy(&d->PMS); r_data_destroy(&d->PMS);
r_data_destroy(&d->MS); r_data_destroy(&d->MS);
r_data_destroy(&d->handshake_messages);
r_data_destroy(&d->session_hash);
ssl_destroy_rec_decoder(&d->c_to_s); ssl_destroy_rec_decoder(&d->c_to_s);
ssl_destroy_rec_decoder(&d->c_to_s_n); ssl_destroy_rec_decoder(&d->c_to_s_n);
ssl_destroy_rec_decoder(&d->s_to_c); ssl_destroy_rec_decoder(&d->s_to_c);
@ -382,6 +388,35 @@ int ssl_decode_record(ssl,dec,direction,ct,version,d)
#endif #endif
} }
int ssl_update_handshake_messages(ssl,data)
ssl_obj *ssl;
Data *data;
{
#ifdef OPENSSL
Data *hms;
UCHAR *d;
int l,r;
hms = ssl->decoder->handshake_messages;
d = data->data-4;
l = data->len+4;
if(hms){
if(!(hms->data = realloc(hms->data,l+hms->len)))
ERETURN(R_NO_MEMORY);
memcpy(hms->data+hms->len,d,l);
hms->len+=l;
}
else{
if(r=r_data_create(&hms,d,l))
ERETURN(r);
ssl->decoder->handshake_messages=hms;
}
#endif
return(0);
}
static int ssl_create_session_lookup_key(ssl,id,idlen,keyp,keyl) static int ssl_create_session_lookup_key(ssl,id,idlen,keyp,keyl)
ssl_obj *ssl; ssl_obj *ssl;
@ -564,6 +599,7 @@ int ssl_process_client_key_exchange(ssl,d,msg,len)
} }
#ifdef OPENSSL #ifdef OPENSSL
static int tls_P_hash(ssl,secret,seed,md,out) static int tls_P_hash(ssl,secret,seed,md,out)
ssl_obj *ssl; ssl_obj *ssl;
@ -810,7 +846,7 @@ static int ssl_generate_keying_material(ssl,d)
ssl_obj *ssl; ssl_obj *ssl;
ssl_decoder *d; ssl_decoder *d;
{ {
Data *key_block=0; Data *key_block=0,temp;
UCHAR _iv_c[8],_iv_s[8]; UCHAR _iv_c[8],_iv_s[8];
UCHAR _key_c[16],_key_s[16]; UCHAR _key_c[16],_key_s[16];
int needed; int needed;
@ -821,6 +857,16 @@ static int ssl_generate_keying_material(ssl,d)
if(r=r_data_alloc(&d->MS,48)) if(r=r_data_alloc(&d->MS,48))
ABORT(r); ABORT(r);
if (ssl->extensions->extended_master_secret) {
if(r=ssl_generate_session_hash(ssl,d))
ABORT(r);
temp.len=0;
if(r=PRF(ssl,d->PMS,"extended master secret",d->session_hash,&temp,
d->MS))
ABORT(r);
}
else
if(r=PRF(ssl,d->PMS,"master secret",d->client_random,d->server_random, if(r=PRF(ssl,d->PMS,"master secret",d->client_random,d->server_random,
d->MS)) d->MS))
ABORT(r); ABORT(r);
@ -958,4 +1004,51 @@ static int ssl_generate_keying_material(ssl,d)
return(_status); return(_status);
} }
static int ssl_generate_session_hash(ssl,d)
ssl_obj *ssl;
ssl_decoder *d;
{
int r,_status,dgi;
unsigned int len;
const EVP_MD *md;
EVP_MD_CTX dgictx;
if(r=r_data_alloc(&d->session_hash,EVP_MAX_MD_SIZE))
ABORT(r);
switch(ssl->version){
case TLSV12_VERSION:
dgi = MAX(DIG_SHA256,ssl->cs->dig)-0x40;
if ((md=EVP_get_digestbyname(digests[dgi])) == NULL) {
DBG((0,"Cannot get EVP for digest %s, openssl library current?",
digests[dgi]));
ERETURN(SSL_BAD_MAC);
}
EVP_DigestInit(&dgictx,md);
EVP_DigestUpdate(&dgictx,d->handshake_messages->data,d->handshake_messages->len);
EVP_DigestFinal(&dgictx,d->session_hash->data,&d->session_hash->len);
break;
case SSLV3_VERSION:
case TLSV1_VERSION:
case TLSV11_VERSION:
EVP_DigestInit(&dgictx,EVP_get_digestbyname("MD5"));
EVP_DigestUpdate(&dgictx,d->handshake_messages->data,d->handshake_messages->len);
EVP_DigestFinal_ex(&dgictx,d->session_hash->data,&d->session_hash->len);
EVP_DigestInit(&dgictx,EVP_get_digestbyname("SHA1"));
EVP_DigestUpdate(&dgictx,d->handshake_messages->data,d->handshake_messages->len);
EVP_DigestFinal(&dgictx,d->session_hash->data+d->session_hash->len,&len);
d->session_hash->len+=len;
break;
default:
ABORT(SSL_CANT_DO_CIPHER);
}
_status=0;
abort:
return(_status);
}
#endif #endif

View file

@ -66,7 +66,8 @@ int ssl_process_client_key_exchange PROTO_LIST((struct ssl_obj_ *,
ssl_decoder *d,UCHAR *msg,int len)); ssl_decoder *d,UCHAR *msg,int len));
int ssl_process_change_cipher_spec PROTO_LIST((ssl_obj *ssl, int ssl_process_change_cipher_spec PROTO_LIST((ssl_obj *ssl,
ssl_decoder *d,int direction)); ssl_decoder *d,int direction));
int ssl_update_handshake_messages PROTO_LIST((ssl_obj *ssl,
Data *data));
int ssl_decode_record PROTO_LIST((ssl_obj *ssl,ssl_decoder *dec,int direction, int ssl_decode_record PROTO_LIST((ssl_obj *ssl,ssl_decoder *dec,int direction,
int ct,int version,Data *d)); int ct,int version,Data *d));