/* * src/lib/krb5/asn.1/krb5_decode.c * * Copyright 1994 by the Massachusetts Institute of Technology. * All Rights Reserved. * * Export of this software from the United States of America may * require a specific license from the United States Government. * It is the responsibility of any person or organization contemplating * export to obtain such a license before exporting. * * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and * distribute this software and its documentation for any purpose and * without fee is hereby granted, provided that the above copyright * notice appear in all copies and that both that copyright notice and * this permission notice appear in supporting documentation, and that * the name of M.I.T. not be used in advertising or publicity pertaining * to distribution of the software without specific, written prior * permission. M.I.T. makes no representations about the suitability of * this software for any purpose. It is provided "as is" without express * or implied warranty. */ #include "krb5.h" #include "krbasn1.h" #include "asn1_k_decode.h" #include "asn1_decode.h" #include "asn1_get.h" /* setup *********************************************************/ /* set up variables */ /* the setup* macros can return, but are always used at function start and thus need no malloc cleanup */ #define setup_buf_only()\ asn1_error_code retval;\ asn1buf buf;\ \ retval = asn1buf_wrap_data(&buf,code);\ if(retval) return retval #define setup_no_tagnum()\ asn1_class class;\ asn1_construction construction;\ setup_buf_only() #define setup_no_length()\ asn1_tagnum tagnum;\ setup_no_tagnum() #define setup()\ int length;\ setup_no_length() /* helper macros for cleanup */ #define clean_return(val) { retval = val; goto error_out; } /* alloc_field is the first thing to allocate storage that may need cleanup */ #define alloc_field(var,type)\ var = (type*)calloc(1,sizeof(type));\ if((var) == NULL) clean_return(ENOMEM) /* process encoding header ***************************************/ /* decode tag and check that it == [APPLICATION tagnum] */ #define check_apptag(tagexpect)\ retval = asn1_get_tag(&buf,&class,&construction,&tagnum,NULL);\ if(retval) clean_return(retval);\ if(class != APPLICATION || construction != CONSTRUCTED) \ clean_return(ASN1_BAD_ID);\ if(tagnum != (tagexpect)) clean_return(KRB5_BADMSGTYPE) /* process a structure *******************************************/ /* decode an explicit tag and place the number in tagnum */ #define next_tag()\ retval = asn1_get_tag(&subbuf,&class,&construction,&tagnum,NULL);\ if(retval) clean_return(retval);\ if(class != CONTEXT_SPECIFIC || construction != CONSTRUCTED)\ clean_return(ASN1_BAD_ID) /* decode sequence header and initialize tagnum with the first field */ #define begin_structure()\ asn1buf subbuf;\ retval = asn1_get_tag(&buf,&class,&construction,&tagnum,&length);\ if(retval) clean_return(retval);\ if(class != UNIVERSAL || construction != CONSTRUCTED ||\ tagnum != ASN1_SEQUENCE) clean_return(ASN1_BAD_ID);\ retval = asn1buf_imbed(&subbuf,&buf,length);\ if(retval) clean_return(retval);\ next_tag() #define end_structure()\ asn1buf_sync(&buf,&subbuf) /* process fields *******************************************/ /* normal fields ************************/ #define get_field_body(var,decoder)\ retval = decoder(&subbuf,&(var));\ if(retval) clean_return(retval);\ next_tag() /* decode a field (<[UNIVERSAL id]> ) check that the id number == tagexpect then decode into var get the next tag */ #define get_field(var,tagexpect,decoder)\ if(tagnum > (tagexpect)) clean_return(ASN1_MISSING_FIELD);\ if(tagnum < (tagexpect)) clean_return(ASN1_MISPLACED_FIELD);\ get_field_body(var,decoder) /* decode (or skip, if not present) an optional field */ #define opt_field(var,tagexpect,decoder)\ if(tagnum == (tagexpect)){ get_field_body(var,decoder); } /* field w/ accompanying length *********/ #define get_lenfield_body(len,var,decoder)\ retval = decoder(&subbuf,&(len),&(var));\ if(retval) clean_return(retval);\ next_tag() /* decode a field w/ its length (for string types) */ #define get_lenfield(len,var,tagexpect,decoder)\ if(tagnum > (tagexpect)) clean_return(ASN1_MISSING_FIELD);\ if(tagnum < (tagexpect)) clean_return(ASN1_MISPLACED_FIELD);\ get_lenfield_body(len,var,decoder) /* decode an optional field w/ length */ #define opt_lenfield(len,var,tagexpect,decoder)\ if(tagnum == (tagexpect)){\ get_lenfield_body(len,var,decoder);\ } /* clean up ******************************************************/ /* finish up */ /* to make things less painful, assume the cleanup is passed rep */ #define cleanup(cleanup_routine)\ return 0; \ error_out: \ if (rep && *rep) \ cleanup_routine(*rep); \ return retval; #define cleanup_none()\ return 0; \ error_out: \ return retval; #define cleanup_manual()\ return 0; #define free_field(rep,f) if ((rep)->f) free((rep)->f) #define clear_field(rep,f) (*(rep))->f = 0 krb5_error_code decode_krb5_authenticator(code, rep) const krb5_data * code; krb5_authenticator ** rep; { setup(); alloc_field(*rep,krb5_authenticator); clear_field(rep,subkey); clear_field(rep,checksum); clear_field(rep,client); check_apptag(2); { begin_structure(); { krb5_kvno kvno; get_field(kvno,0,asn1_decode_kvno); if(kvno != KVNO) clean_return(KRB5KDC_ERR_BAD_PVNO); } alloc_field((*rep)->client,krb5_principal_data); get_field((*rep)->client,1,asn1_decode_realm); get_field((*rep)->client,2,asn1_decode_principal_name); if(tagnum == 3){ alloc_field((*rep)->checksum,krb5_checksum); get_field(*((*rep)->checksum),3,asn1_decode_checksum); } get_field((*rep)->cusec,4,asn1_decode_int32); get_field((*rep)->ctime,5,asn1_decode_kerberos_time); if(tagnum == 6){ alloc_field((*rep)->subkey,krb5_keyblock); } opt_field(*((*rep)->subkey),6,asn1_decode_encryption_key); opt_field((*rep)->seq_number,7,asn1_decode_int32); opt_field((*rep)->authorization_data,8,asn1_decode_authorization_data); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,subkey); free_field(*rep,checksum); free_field(*rep,client); free(*rep); } return retval; } krb5_error_code decode_krb5_ticket(code, rep) const krb5_data * code; krb5_ticket ** rep; { setup(); alloc_field(*rep,krb5_ticket); clear_field(rep,server); check_apptag(1); { begin_structure(); { krb5_kvno kvno; get_field(kvno,0,asn1_decode_kvno); if(kvno != KVNO) return KRB5KDC_ERR_BAD_PVNO; } alloc_field((*rep)->server,krb5_principal_data); get_field((*rep)->server,1,asn1_decode_realm); get_field((*rep)->server,2,asn1_decode_principal_name); get_field((*rep)->enc_part,3,asn1_decode_encrypted_data); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,server); free(*rep); } return retval; } krb5_error_code decode_krb5_encryption_key(code, rep) const krb5_data * code; krb5_keyblock ** rep; { setup(); alloc_field(*rep,krb5_keyblock); { begin_structure(); get_field((*rep)->enctype,0,asn1_decode_enctype); get_lenfield((*rep)->length,(*rep)->contents,1,asn1_decode_octetstring); end_structure(); (*rep)->magic = KV5M_KEYBLOCK; } cleanup(free); } krb5_error_code decode_krb5_enc_tkt_part(code, rep) const krb5_data * code; krb5_enc_tkt_part ** rep; { setup(); alloc_field(*rep,krb5_enc_tkt_part); clear_field(rep,session); clear_field(rep,client); check_apptag(3); { begin_structure(); get_field((*rep)->flags,0,asn1_decode_ticket_flags); alloc_field((*rep)->session,krb5_keyblock); get_field(*((*rep)->session),1,asn1_decode_encryption_key); alloc_field((*rep)->client,krb5_principal_data); get_field((*rep)->client,2,asn1_decode_realm); get_field((*rep)->client,3,asn1_decode_principal_name); get_field((*rep)->transited,4,asn1_decode_transited_encoding); get_field((*rep)->times.authtime,5,asn1_decode_kerberos_time); opt_field((*rep)->times.starttime,6,asn1_decode_kerberos_time); get_field((*rep)->times.endtime,7,asn1_decode_kerberos_time); opt_field((*rep)->times.renew_till,8,asn1_decode_kerberos_time); opt_field((*rep)->caddrs,9,asn1_decode_host_addresses); opt_field((*rep)->authorization_data,10,asn1_decode_authorization_data); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,session); free_field(*rep,client); free(*rep); } return retval; } krb5_error_code decode_krb5_enc_kdc_rep_part(code, rep) const krb5_data * code; krb5_enc_kdc_rep_part ** rep; { setup_no_length(); alloc_field(*rep,krb5_enc_kdc_rep_part); retval = asn1_get_tag(&buf,&class,&construction,&tagnum,NULL); if(retval) clean_return(retval); if(class != APPLICATION || construction != CONSTRUCTED) clean_return(ASN1_BAD_ID); if(tagnum == 25) (*rep)->msg_type = KRB5_AS_REP; else if(tagnum == 26) (*rep)->msg_type = KRB5_TGS_REP; else clean_return(KRB5_BADMSGTYPE); retval = asn1_decode_enc_kdc_rep_part(&buf,*rep); if(retval) clean_return(retval); cleanup(free); } krb5_error_code decode_krb5_as_rep(code, rep) const krb5_data * code; krb5_kdc_rep ** rep; { setup_no_length(); alloc_field(*rep,krb5_kdc_rep); check_apptag(11); retval = asn1_decode_kdc_rep(&buf,*rep); if(retval) clean_return(retval); #ifdef KRB5_MSGTYPE_STRICT if((*rep)->msg_type != KRB5_AS_REP) clean_return(KRB5_BADMSGTYPE); #endif cleanup(free); } krb5_error_code decode_krb5_tgs_rep(code, rep) const krb5_data * code; krb5_kdc_rep ** rep; { setup_no_length(); alloc_field(*rep,krb5_kdc_rep); check_apptag(13); retval = asn1_decode_kdc_rep(&buf,*rep); if(retval) clean_return(retval); #ifdef KRB5_MSGTYPE_STRICT if((*rep)->msg_type != KRB5_TGS_REP) clean_return(KRB5_BADMSGTYPE); #endif cleanup(free); } krb5_error_code decode_krb5_ap_req(code, rep) const krb5_data * code; krb5_ap_req ** rep; { setup(); alloc_field(*rep,krb5_ap_req); clear_field(rep,ticket); check_apptag(14); { begin_structure(); { krb5_kvno kvno; get_field(kvno,0,asn1_decode_kvno); if(kvno != KVNO) clean_return(KRB5KDC_ERR_BAD_PVNO); } { krb5_msgtype msg_type; get_field(msg_type,1,asn1_decode_msgtype); #ifdef KRB5_MSGTYPE_STRICT if(msg_type != KRB5_AP_REQ) clean_return(KRB5_BADMSGTYPE); #endif } get_field((*rep)->ap_options,2,asn1_decode_ap_options); alloc_field((*rep)->ticket,krb5_ticket); get_field(*((*rep)->ticket),3,asn1_decode_ticket); get_field((*rep)->authenticator,4,asn1_decode_encrypted_data); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,ticket); free(*rep); } return retval; } krb5_error_code decode_krb5_ap_rep(code, rep) const krb5_data * code; krb5_ap_rep ** rep; { setup(); alloc_field(*rep,krb5_ap_rep); check_apptag(15); { begin_structure(); { krb5_kvno kvno; get_field(kvno,0,asn1_decode_kvno); if(kvno != KVNO) clean_return(KRB5KDC_ERR_BAD_PVNO); } { krb5_msgtype msg_type; get_field(msg_type,1,asn1_decode_msgtype); #ifdef KRB5_MSGTYPE_STRICT if(msg_type != KRB5_AP_REP) clean_return(KRB5_BADMSGTYPE); #endif } get_field((*rep)->enc_part,2,asn1_decode_encrypted_data); end_structure(); } cleanup(free); } krb5_error_code decode_krb5_ap_rep_enc_part(code, rep) const krb5_data * code; krb5_ap_rep_enc_part ** rep; { setup(); alloc_field(*rep,krb5_ap_rep_enc_part); clear_field(rep,subkey); check_apptag(27); { begin_structure(); get_field((*rep)->ctime,0,asn1_decode_kerberos_time); get_field((*rep)->cusec,1,asn1_decode_int32); if(tagnum == 2){ alloc_field((*rep)->subkey,krb5_keyblock); } opt_field(*((*rep)->subkey),2,asn1_decode_encryption_key); opt_field((*rep)->seq_number,3,asn1_decode_int32); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,subkey); free(*rep); } return retval; } krb5_error_code decode_krb5_as_req(code, rep) const krb5_data * code; krb5_kdc_req ** rep; { setup_no_length(); alloc_field(*rep,krb5_kdc_req); check_apptag(10); retval = asn1_decode_kdc_req(&buf,*rep); if(retval) clean_return(retval); #ifdef KRB5_MSGTYPE_STRICT if((*rep)->msg_type != KRB5_AS_REQ) clean_return(KRB5_BADMSGTYPE); #endif cleanup(free); } krb5_error_code decode_krb5_tgs_req(code, rep) const krb5_data * code; krb5_kdc_req ** rep; { setup_no_length(); alloc_field(*rep,krb5_kdc_req); check_apptag(12); retval = asn1_decode_kdc_req(&buf,*rep); if(retval) clean_return(retval); #ifdef KRB5_MSGTYPE_STRICT if((*rep)->msg_type != KRB5_TGS_REQ) clean_return(KRB5_BADMSGTYPE); #endif cleanup(free); } krb5_error_code decode_krb5_kdc_req_body(code, rep) const krb5_data * code; krb5_kdc_req ** rep; { setup_buf_only(); alloc_field(*rep,krb5_kdc_req); retval = asn1_decode_kdc_req_body(&buf,*rep); if(retval) clean_return(retval); cleanup(free); } krb5_error_code decode_krb5_safe(code, rep) const krb5_data * code; krb5_safe ** rep; { setup(); alloc_field(*rep,krb5_safe); clear_field(rep,checksum); check_apptag(20); { begin_structure(); { krb5_kvno kvno; get_field(kvno,0,asn1_decode_kvno); if(kvno != KVNO) clean_return(KRB5KDC_ERR_BAD_PVNO); } { krb5_msgtype msg_type; get_field(msg_type,1,asn1_decode_msgtype); #ifdef KRB5_MSGTYPE_STRICT if(msg_type != KRB5_SAFE) clean_return(KRB5_BADMSGTYPE); #endif } get_field(**rep,2,asn1_decode_krb_safe_body); alloc_field((*rep)->checksum,krb5_checksum); get_field(*((*rep)->checksum),3,asn1_decode_checksum); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,checksum); free(*rep); } return retval; } krb5_error_code decode_krb5_priv(code, rep) const krb5_data * code; krb5_priv ** rep; { setup(); alloc_field(*rep,krb5_priv); check_apptag(21); { begin_structure(); { krb5_kvno kvno; get_field(kvno,0,asn1_decode_kvno); if(kvno != KVNO) clean_return(KRB5KDC_ERR_BAD_PVNO); } { krb5_msgtype msg_type; get_field(msg_type,1,asn1_decode_msgtype); #ifdef KRB5_MSGTYPE_STRICT if(msg_type != KRB5_PRIV) clean_return(KRB5_BADMSGTYPE); #endif } get_field((*rep)->enc_part,3,asn1_decode_encrypted_data); end_structure(); } cleanup(free); } krb5_error_code decode_krb5_enc_priv_part(code, rep) const krb5_data * code; krb5_priv_enc_part ** rep; { setup(); alloc_field(*rep,krb5_priv_enc_part); clear_field(rep,r_address); clear_field(rep,s_address); check_apptag(28); { begin_structure(); get_lenfield((*rep)->user_data.length,(*rep)->user_data.data,0,asn1_decode_charstring); opt_field((*rep)->timestamp,1,asn1_decode_kerberos_time); opt_field((*rep)->usec,2,asn1_decode_int32); opt_field((*rep)->seq_number,3,asn1_decode_int32); alloc_field((*rep)->s_address,krb5_address); get_field(*((*rep)->s_address),4,asn1_decode_host_address); if(tagnum == 5){ alloc_field((*rep)->r_address,krb5_address); } opt_field(*((*rep)->r_address),5,asn1_decode_host_address); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,r_address); free_field(*rep,s_address); free(*rep); } return retval; } krb5_error_code decode_krb5_cred(code, rep) const krb5_data * code; krb5_cred ** rep; { setup(); alloc_field(*rep,krb5_cred); check_apptag(22); { begin_structure(); { krb5_kvno kvno; get_field(kvno,0,asn1_decode_kvno); if(kvno != KVNO) clean_return(KRB5KDC_ERR_BAD_PVNO); } { krb5_msgtype msg_type; get_field(msg_type,1,asn1_decode_msgtype); #ifdef KRB5_MSGTYPE_STRICT if(msg_type != KRB5_CRED) clean_return(KRB5_BADMSGTYPE); #endif } get_field((*rep)->tickets,2,asn1_decode_sequence_of_ticket); get_field((*rep)->enc_part,3,asn1_decode_encrypted_data); end_structure(); } cleanup(free); } krb5_error_code decode_krb5_enc_cred_part(code, rep) const krb5_data * code; krb5_cred_enc_part ** rep; { setup(); alloc_field(*rep,krb5_cred_enc_part); clear_field(rep,r_address); clear_field(rep,s_address); check_apptag(29); { begin_structure(); get_field((*rep)->ticket_info,0,asn1_decode_sequence_of_krb_cred_info); opt_field((*rep)->nonce,1,asn1_decode_int32); opt_field((*rep)->timestamp,2,asn1_decode_kerberos_time); opt_field((*rep)->usec,3,asn1_decode_int32); if(tagnum == 4){ alloc_field((*rep)->s_address,krb5_address); } opt_field(*((*rep)->s_address),4,asn1_decode_host_address); if(tagnum == 5){ alloc_field((*rep)->r_address,krb5_address); } opt_field(*((*rep)->r_address),5,asn1_decode_host_address); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,r_address); free_field(*rep,s_address); free(*rep); } return retval; } krb5_error_code decode_krb5_error(code, rep) const krb5_data * code; krb5_error ** rep; { setup(); alloc_field(*rep,krb5_error); clear_field(rep,server); clear_field(rep,client); check_apptag(30); { begin_structure(); { krb5_kvno kvno; get_field(kvno,0,asn1_decode_kvno); if(kvno != KVNO) clean_return(KRB5KDC_ERR_BAD_PVNO); } { krb5_msgtype msg_type; get_field(msg_type,1,asn1_decode_msgtype); #ifdef KRB5_MSGTYPE_STRICT if(msg_type != KRB5_ERROR) clean_return(KRB5_BADMSGTYPE); #endif } opt_field((*rep)->ctime,2,asn1_decode_kerberos_time); opt_field((*rep)->cusec,3,asn1_decode_int32); get_field((*rep)->stime,4,asn1_decode_kerberos_time); get_field((*rep)->susec,5,asn1_decode_int32); get_field((*rep)->error,6,asn1_decode_ui_4); if(tagnum == 7){ alloc_field((*rep)->client,krb5_principal_data); } opt_field((*rep)->client,7,asn1_decode_realm); opt_field((*rep)->client,8,asn1_decode_principal_name); alloc_field((*rep)->server,krb5_principal_data); get_field((*rep)->server,9,asn1_decode_realm); get_field((*rep)->server,10,asn1_decode_principal_name); opt_lenfield((*rep)->text.length,(*rep)->text.data,11,asn1_decode_generalstring); opt_lenfield((*rep)->e_data.length,(*rep)->e_data.data,12,asn1_decode_charstring); end_structure(); } cleanup_manual(); error_out: if (rep && *rep) { free_field(*rep,server); free_field(*rep,client); free(*rep); } return retval; } krb5_error_code decode_krb5_authdata(code, rep) const krb5_data * code; krb5_authdata *** rep; { setup_buf_only(); *rep = 0; retval = asn1_decode_authorization_data(&buf,rep); if(retval) clean_return(retval); cleanup_none(); /* we're not allocating anything here... */ } krb5_error_code decode_krb5_pwd_sequence(code, rep) const krb5_data * code; passwd_phrase_element ** rep; { setup_buf_only(); alloc_field(*rep,passwd_phrase_element); retval = asn1_decode_passwdsequence(&buf,*rep); if(retval) clean_return(retval); cleanup(free); } krb5_error_code decode_krb5_pwd_data(code, rep) const krb5_data * code; krb5_pwd_data ** rep; { setup(); alloc_field(*rep,krb5_pwd_data); { begin_structure(); get_field((*rep)->sequence_count,0,asn1_decode_int); get_field((*rep)->element,1,asn1_decode_sequence_of_passwdsequence); end_structure (); } cleanup(free); } krb5_error_code decode_krb5_padata_sequence(code, rep) const krb5_data * code; krb5_pa_data ***rep; { setup_buf_only(); *rep = 0; retval = asn1_decode_sequence_of_pa_data(&buf,rep); if(retval) clean_return(retval); cleanup_none(); /* we're not allocating anything here */ } krb5_error_code decode_krb5_alt_method(code, rep) const krb5_data * code; krb5_alt_method ** rep; { setup(); alloc_field(*rep,krb5_alt_method); { begin_structure(); get_field((*rep)->method,0,asn1_decode_int32); if (tagnum == 1) { get_lenfield((*rep)->length,(*rep)->data,1,asn1_decode_octetstring); } else { (*rep)->length = 0; (*rep)->data = 0; } (*rep)->magic = KV5M_ALT_METHOD; end_structure(); } cleanup(free); } krb5_error_code decode_krb5_etype_info(code, rep) const krb5_data * code; krb5_etype_info_entry ***rep; { setup_buf_only(); *rep = 0; retval = asn1_decode_etype_info(&buf,rep); if(retval) clean_return(retval); cleanup_none(); /* we're not allocating anything here */ } krb5_error_code decode_krb5_enc_data(code, rep) const krb5_data * code; krb5_enc_data ** rep; { setup_buf_only(); alloc_field(*rep,krb5_enc_data); retval = asn1_decode_encrypted_data(&buf,*rep); if(retval) clean_return(retval); cleanup(free); } krb5_error_code decode_krb5_pa_enc_ts(code, rep) const krb5_data * code; krb5_pa_enc_ts ** rep; { setup(); alloc_field(*rep,krb5_pa_enc_ts); { begin_structure(); get_field((*rep)->patimestamp,0,asn1_decode_kerberos_time); if (tagnum == 1) { get_field((*rep)->pausec,1,asn1_decode_int); } else (*rep)->pausec = 0; end_structure (); } cleanup(free); }