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#include <cstring>
#include <vector>
#include <openssl/sha.h>
#include <openssl/hmac.h>
#include <opkele/util.h>
#include <opkele/util-internal.h>
#include <opkele/exception.h>
#include <opkele/server.h>
#include <opkele/data.h>
namespace opkele {
using namespace std;
void server_t::associate(const params_t& pin,params_t& pout) {
util::dh_t dh;
util::bignum_t c_pub;
unsigned char key_sha1[SHA_DIGEST_LENGTH];
enum {
sess_cleartext,
sess_dh_sha1
} st = sess_cleartext;
if(
pin.has_param("openid.session_type")
&& pin.get_param("openid.session_type")=="DH-SHA1" ) {
/* TODO: fallback to cleartext in case of exceptions here? */
if(!(dh = DH_new()))
throw exception_openssl(OPKELE_CP_ "failed to DH_new()");
c_pub = util::base64_to_bignum(pin.get_param("openid.dh_consumer_public"));
if(pin.has_param("openid.dh_modulus"))
dh->p = util::base64_to_bignum(pin.get_param("openid.dh_modulus"));
else
dh->p = util::dec_to_bignum(data::_default_p);
if(pin.has_param("openid.dh_gen"))
dh->g = util::base64_to_bignum(pin.get_param("openid.dh_gen"));
else
dh->g = util::dec_to_bignum(data::_default_g);
if(!DH_generate_key(dh))
throw exception_openssl(OPKELE_CP_ "failed to DH_generate_key()");
vector<unsigned char> ck(DH_size(dh)+1);
unsigned char *ckptr = &(ck.front())+1;
int cklen = DH_compute_key(ckptr,c_pub,dh);
if(cklen<0)
throw exception_openssl(OPKELE_CP_ "failed to DH_compute_key()");
if(cklen && (*ckptr)&0x80) {
(*(--ckptr)) = 0; ++cklen;
}
SHA1(ckptr,cklen,key_sha1);
st = sess_dh_sha1;
}
assoc_t assoc = alloc_assoc(mode_associate);
time_t now = time(0);
pout.clear();
pout["assoc_type"] = assoc->assoc_type();
pout["assoc_handle"] = assoc->handle();
/* TODO: eventually remove deprecated stuff */
pout["issued"] = util::time_to_w3c(now);
pout["expiry"] = util::time_to_w3c(now+assoc->expires_in());
pout["expires_in"] = util::long_to_string(assoc->expires_in());
secret_t secret = assoc->secret();
switch(st) {
case sess_dh_sha1:
pout["session_type"] = "DH-SHA1";
pout["dh_server_public"] = util::bignum_to_base64(dh->pub_key);
secret.enxor_to_base64(key_sha1,pout["enc_mac_key"]);
break;
default:
secret.to_base64(pout["mac_key"]);
break;
}
}
void server_t::checkid_immediate(const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
checkid_(mode_checkid_immediate,pin,return_to,pout,ext);
}
void server_t::checkid_setup(const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
checkid_(mode_checkid_setup,pin,return_to,pout,ext);
}
void server_t::checkid_(mode_t mode,const params_t& pin,string& return_to,params_t& pout,extension_t *ext) {
if(mode!=mode_checkid_immediate && mode!=mode_checkid_setup)
throw bad_input(OPKELE_CP_ "invalid checkid_* mode");
pout.clear();
assoc_t assoc;
try {
assoc = retrieve_assoc(pin.get_param("openid.assoc_handle"));
}catch(failed_lookup& fl) {
// no handle specified or no valid handle found, going dumb
assoc = alloc_assoc(mode_checkid_setup);
if(pin.has_param("openid.assoc_handle"))
pout["invalidate_handle"]=pin.get_param("openid.assoc_handle");
}
string trust_root;
try {
trust_root = pin.get_param("openid.trust_root");
}catch(failed_lookup& fl) { }
string identity = pin.get_param("openid.identity");
return_to = pin.get_param("openid.return_to");
validate(*assoc,pin,identity,trust_root);
pout["mode"] = "id_res";
pout["assoc_handle"] = assoc->handle();
if(pin.has_param("openid.assoc_handle") && assoc->stateless())
pout["invalidate_handle"] = pin.get_param("openid.assoc_handle");
pout["identity"] = identity;
pout["return_to"] = return_to;
/* TODO: eventually remove deprecated stuff */
time_t now = time(0);
pout["issued"] = util::time_to_w3c(now);
pout["valid_to"] = util::time_to_w3c(now+120);
pout["exipres_in"] = "120";
pout["signed"]="mode,identity,return_to";
if(ext) ext->checkid_hook(pin,pout);
pout["sig"] = util::base64_signature(assoc,pout);
}
void server_t::check_authentication(const params_t& pin,params_t& pout) {
vector<unsigned char> sig;
const string& sigenc = pin.get_param("openid.sig");
util::decode_base64(sigenc,sig);
assoc_t assoc;
try {
assoc = retrieve_assoc(pin.get_param("openid.assoc_handle"));
}catch(failed_lookup& fl) {
throw failed_assertion(OPKELE_CP_ "invalid handle or handle not specified");
}
if(!assoc->stateless())
throw stateful_handle(OPKELE_CP_ "will not do check_authentication on a stateful handle");
const string& slist = pin.get_param("openid.signed");
string kv;
string::size_type p =0;
while(true) {
string::size_type co = slist.find(',',p);
string f = (co==string::npos)?slist.substr(p):slist.substr(p,co-p);
kv += f;
kv += ':';
if(f=="mode")
kv += "id_res";
else {
f.insert(0,"openid.");
kv += pin.get_param(f);
}
kv += '\n';
if(co==string::npos)
break;
p = co+1;
}
secret_t secret = assoc->secret();
unsigned int md_len = 0;
unsigned char *md = HMAC(
EVP_sha1(),
&(secret.front()),secret.size(),
(const unsigned char *)kv.data(),kv.length(),
0,&md_len);
pout.clear();
if(sig.size()==md_len && !memcmp(&(sig.front()),md,md_len)) {
pout["is_valid"]="true";
pout["lifetime"]="60"; /* TODO: eventually remove deprecated stuff */
}else{
pout["is_valid"]="false";
pout["lifetime"]="0"; /* TODO: eventually remove deprecated stuff */
}
if(pin.has_param("openid.invalidate_handle")) {
string h = pin.get_param("openid.invalidate_handle");
try {
assoc_t tmp = retrieve_assoc(h);
}catch(invalid_handle& ih) {
pout["invalidate_handle"] = h;
}catch(failed_lookup& fl) { }
}
}
}
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