| -rw-r--r-- | lib/basic_op.cc | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/lib/basic_op.cc b/lib/basic_op.cc new file mode 100644 index 0000000..22012bc --- a/dev/null +++ b/lib/basic_op.cc @@ -0,0 +1,320 @@ +#include <time.h> +#include <cassert> +#include <openssl/sha.h> +#include <openssl/hmac.h> +#include <opkele/data.h> +#include <opkele/basic_op.h> +#include <opkele/exception.h> +#include <opkele/util.h> +#include <opkele/uris.h> + +namespace opkele { + + void basic_op::reset_vars() { + assoc.reset(); + return_to.clear(); realm.clear(); + claimed_id.clear(); identity.clear(); + invalidate_handle.clear(); + } + + bool basic_op::has_return_to() const { + return !return_to.empty(); + } + const string& basic_op::get_return_to() const { + if(return_to.empty()) + throw no_return_to(OPKELE_CP_ "No return_to URL provided with request"); + return return_to; + } + + const string& basic_op::get_realm() const { + assert(!realm.empty()); + return realm; + } + + bool basic_op::has_identity() const { + return !identity.empty(); + } + const string& basic_op::get_claimed_id() const { + if(claimed_id.empty()) + throw non_identity(OPKELE_CP_ "attempting to retrieve claimed_id of non-identity related request"); + assert(!identity.empty()); + return claimed_id; + } + const string& basic_op::get_identity() const { + if(identity.empty()) + throw non_identity(OPKELE_CP_ "attempting to retrieve identity of non-identity related request"); + assert(!claimed_id.empty()); + return identity; + } + + bool basic_op::is_id_select() const { + return identity==IDURI_SELECT20; + } + + void basic_op::select_identity(const string& c,const string& i) { + claimed_id = c; identity = i; + } + void basic_op::set_claimed_id(const string& c) { + claimed_id = c; + } + + basic_openid_message& basic_op::associate( + basic_openid_message& oum, + const basic_openid_message& inm) try { + assert(inm.get_field("mode")=="associate"); + util::dh_t dh; + util::bignum_t c_pub; + unsigned char key_digest[SHA256_DIGEST_LENGTH]; + size_t d_len = 0; + enum { + sess_cleartext, sess_dh_sha1, sess_dh_sha256 + } st = sess_cleartext; + string sts = inm.get_field("session_type"); + string ats = inm.get_field("assoc_type"); + if(sts=="DH-SHA1" || sts=="DH-SHA256") { + if(!(dh = DH_new())) + throw exception_openssl(OPKELE_CP_ "failed to DH_new()"); + c_pub = util::base64_to_bignum(inm.get_field("dh_consumer_public")); + try { dh->p = util::base64_to_bignum(inm.get_field("dh_modulus")); + }catch(failed_lookup&) { + dh->p = util::dec_to_bignum(data::_default_p); } + try { dh->g = util::base64_to_bignum(inm.get_field("dh_gen")); + }catch(failed_lookup&) { + 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; } + if(sts=="DH-SHA1") { + SHA1(ckptr,cklen,key_digest); d_len = SHA_DIGEST_LENGTH; + }else if(sts=="DH-SHA256") { + SHA256(ckptr,cklen,key_digest); d_len = SHA256_DIGEST_LENGTH; + }else + throw internal_error(OPKELE_CP_ "I thought I knew the session type"); + }else + throw unsupported(OPKELE_CP_ "Unsupported session_type"); + assoc_t assoc; + if(ats=="HMAC-SHA1") + assoc = alloc_assoc(ats,SHA_DIGEST_LENGTH,true); + else if(ats=="HMAC-SHA256") + assoc = alloc_assoc(ats,SHA256_DIGEST_LENGTH,true); + else + throw unsupported(OPKELE_CP_ "Unsupported assoc_type"); + oum.reset_fields(); + oum.set_field("ns",OIURI_OPENID20); + oum.set_field("assoc_type",assoc->assoc_type()); + oum.set_field("assoc_handle",assoc->handle()); + oum.set_field("expires_in",util::long_to_string(assoc->expires_in())); + secret_t secret = assoc->secret(); + if(sts=="DH-SHA1" || sts=="DH-SHA256") { + if(d_len != secret.size()) + throw bad_input(OPKELE_CP_ "Association secret and session MAC are not of the same size"); + oum.set_field("session_type",sts); + oum.set_field("dh_server_public",util::bignum_to_base64(dh->pub_key)); + string b64; secret.enxor_to_base64(key_digest,b64); + oum.set_field("enc_mac_key",b64); + }else /* TODO: support cleartext over encrypted connection */ + throw unsupported(OPKELE_CP_ "Unsupported session type"); + return oum; + } catch(unsupported& u) { + oum.reset_fields(); + oum.set_field("ns",OIURI_OPENID20); + oum.set_field("error",u.what()); + oum.set_field("error_code","unsupported-type"); + oum.set_field("session_type","DH-SHA256"); + oum.set_field("assoc_type","HMAC-SHA256"); + return oum; + } + + void basic_op::checkid_(const basic_openid_message& inm, + extension_t *ext) { + reset_vars(); + string mode = inm.get_field("mode"); + if(mode=="checkid_setup") + mode = mode_checkid_setup; + else if(mode=="checkid_immediate") + mode = mode_checkid_immediate; + else + throw bad_input(OPKELE_CP_ "Invalid checkid_* mode"); + try { + assoc = retrieve_assoc(invalidate_handle=inm.get_field("assoc_handle")); + invalidate_handle.clear(); + }catch(failed_lookup&) { + // no handle specified or no valid assoc found, go dumb + assoc = alloc_assoc("HMAC-SHA256",SHA256_DIGEST_LENGTH,true); + } + try { + openid2 = (inm.get_field("ns")==OIURI_OPENID20); + }catch(failed_lookup&) { openid2 = false; } + try { + return_to = inm.get_field("return_to"); + }catch(failed_lookup&) { } + if(openid2) { + try { + realm = inm.get_field("realm"); + }catch(failed_lookup&) { + try { + realm = inm.get_field("trust_root"); + }catch(failed_lookup&) { + if(return_to.empty()) + throw bad_input(OPKELE_CP_ + "Both realm and return_to are unset"); + realm = return_to; + } + } + }else{ + try { + realm = inm.get_field("trust_root"); + }catch(failed_lookup&) { + if(return_to.empty()) + throw bad_input(OPKELE_CP_ + "Both realm and return_to are unset"); + realm = return_to; + } + } + try { + identity = inm.get_field("identity"); + try { + claimed_id = inm.get_field("claimed_id"); + }catch(failed_lookup&) { + if(openid2) + throw bad_input(OPKELE_CP_ + "claimed_id and identity must be either both present or both absent"); + } + }catch(failed_lookup&) { + if(openid2 && inm.has_field("claimed_id")) + throw bad_input(OPKELE_CP_ + "claimed_id and identity must be either both present or both absent"); + } + verify_return_to(); + } + + basic_openid_message& basic_op::id_res(basic_openid_message& om) { + assert(assoc); + assert(!return_to.empty()); + assert(!is_id_select()); + time_t now = time(0); + struct tm gmt; gmtime_r(&now,&gmt); + char w3timestr[24]; + if(!strftime(w3timestr,sizeof(w3timestr),"%Y-%m-%dT%H:%M:%SZ",&gmt)) + throw failed_conversion(OPKELE_CP_ + "Failed to build time string for nonce" ); + om.set_field("ns",OIURI_OPENID20); + om.set_field("mode","id_res"); + om.set_field("op_endpoint",get_op_endpoint()); + string ats = "ns,mode,op_endpoint,return_to,response_nonce," + "assoc_handle,signed"; + if(!identity.empty()) { + om.set_field("identity",identity); + om.set_field("claimed_id",claimed_id); + ats += ",identity,claimed_id"; + } + om.set_field("return_to",return_to); + string nonce = w3timestr; + om.set_field("response_nonce",alloc_nonce(nonce,assoc->stateless())); + if(!invalidate_handle.empty()) { + om.set_field("invalidate_handle",invalidate_handle); + ats += ",invalidate_handle"; + } + om.set_field("assoc_handle",assoc->handle()); + om.add_to_signed(ats); + om.set_field("sig",util::base64_signature(assoc,om)); + return om; + } + + basic_openid_message& basic_op::cancel(basic_openid_message& om) { + assert(!return_to.empty()); + om.set_field("ns",OIURI_OPENID20); + om.set_field("mode","cancel"); + return om; + } + + basic_openid_message& basic_op::error(basic_openid_message& om, + const string& error,const string& contact, + const string& reference ) { + assert(!return_to.empty()); + om.set_field("ns",OIURI_OPENID20); + om.set_field("mode","error"); + om.set_field("error",error); + om.set_field("contact",contact); + om.set_field("reference",reference); + return om; + } + + basic_openid_message& basic_op::setup_needed( + basic_openid_message& oum,const basic_openid_message& inm) { + assert(mode==mode_checkid_immediate); + assert(!return_to.empty()); + if(openid2) { + oum.set_field("ns",OIURI_OPENID20); + oum.set_field("mode","setup_needed"); + }else{ + oum.set_field("mode","id_res"); + static const string setupmode = "checkid_setup"; + oum.set_field("user_setup_url", + util::change_mode_message_proxy(inm,setupmode) + .append_query(get_op_endpoint())); + } + return oum; + } + + basic_openid_message& basic_op::check_authentication( + basic_openid_message& oum, + const basic_openid_message& inm) try { + assert(inm.get_field("mode")=="check_authentication"); + oum.reset_fields(); + oum.set_field("ns",OIURI_OPENID20); + bool o2; + try { + o2 = (inm.get_field("ns")==OIURI_OPENID20); + }catch(failed_lookup&) { o2 = false; } + string nonce; + if(o2) { + try { + if(!check_nonce(nonce = inm.get_field("response_nonce"))) + throw failed_check_authentication(OPKELE_CP_ "Invalid nonce"); + }catch(failed_lookup&) { + throw failed_check_authentication(OPKELE_CP_ "No nonce provided with check_authentication request"); + } + } + try { + assoc = retrieve_assoc(inm.get_field("assoc_handle")); + if(!assoc->stateless()) + throw failed_check_authentication(OPKELE_CP_ "Will not do check_authentication on a stateful handle"); + }catch(failed_lookup&) { + throw failed_check_authentication(OPKELE_CP_ "No assoc_handle or invalid assoc_handle specified with check_authentication request"); + } + static const string idresmode = "id_res"; + try { + if(util::base64_signature(assoc,util::change_mode_message_proxy(inm,idresmode))!=inm.get_field("sig")) + throw failed_check_authentication(OPKELE_CP_ "Signature mismatch"); + }catch(failed_lookup&) { + throw failed_check_authentication(OPKELE_CP_ "failed to calculate signature"); + } + oum.set_field("is_valid","true"); + try { + string h = inm.get_field("invalidate_handle"); + try { + assoc_t ih = retrieve_assoc(h); + }catch(invalid_handle& ih) { + oum.set_field("invalidate_handle",h); + }catch(failed_lookup& ih) { + oum.set_field("invalidate_handle",h); + } + }catch(failed_lookup&) { } + if(o2) { + assert(!nonce.empty()); + invalidate_nonce(nonce); + } + return oum; + }catch(failed_check_authentication& ) { + oum.set_field("is_valid","false"); + return oum; + } + +} |