/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
 * src/lib/krb5/asn.1/krb5_decode.c
 *
 * Copyright 1994, 2008 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.  Furthermore if you modify this software you must label
 * your software as modified software and not distribute it in such a
 * fashion that it might be confused with the original M.I.T. software.
 * 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 "k5-int.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(type)                    \
    asn1_error_code retval;                     \
    asn1buf buf;                                \
    type rep = NULL;                            \
                                                \
    *repptr = NULL;                             \
    retval = asn1buf_wrap_data(&buf,code);      \
    if (retval) return retval

#define setup_no_tagnum(type)                   \
    asn1_class asn1class;                       \
    asn1_construction construction;             \
    setup_buf_only(type)

#define setup_no_length(type)                   \
    asn1_tagnum tagnum;                         \
    setup_no_tagnum(type)

#define setup(type)                             \
    unsigned int length;                        \
    setup_no_length(type)

/* 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)                        \
    var = calloc(1,sizeof(*var));               \
    if ((var) == NULL) clean_return(ENOMEM)

/*
 * Allocate a principal and initialize enough fields for
 * krb5_free_principal to have defined behavior.
 */
#define alloc_principal(var)                    \
    alloc_field(var);                           \
    var->realm.data = NULL;                     \
    var->data = NULL

/* process encoding header ***************************************/
/* decode tag and check that it == [APPLICATION tagnum] */
#define check_apptag(tagexpect)                                         \
    {                                                                   \
        taginfo t1;                                                     \
        retval = asn1_get_tag_2(&buf, &t1);                             \
        if (retval) clean_return (retval);                              \
        if (t1.asn1class != APPLICATION || t1.construction != CONSTRUCTED) \
            clean_return(ASN1_BAD_ID);                                  \
        if (t1.tagnum != (tagexpect)) clean_return(KRB5_BADMSGTYPE);    \
        asn1class = t1.asn1class;                                       \
        construction = t1.construction;                                 \
        tagnum = t1.tagnum;                                             \
    }



/* process a structure *******************************************/

/* decode an explicit tag and place the number in tagnum */
#define next_tag_from_buf(buf)                  \
    { taginfo t2;                               \
        retval = asn1_get_tag_2(&(buf), &t2);   \
        if (retval) clean_return(retval);       \
        asn1class = t2.asn1class;               \
        construction = t2.construction;         \
        tagnum = t2.tagnum;                     \
        indef = t2.indef;                       \
        taglen = t2.length;                     \
    }
#define next_tag() next_tag_from_buf(subbuf)


static asn1_error_code
asn1_get_eoc_tag (asn1buf *buf)
{
    asn1_error_code retval;
    taginfo t;

    retval = asn1_get_tag_2(buf, &t);
    if (retval)
        return retval;
    if (t.asn1class != UNIVERSAL || t.tagnum || t.indef)
        return ASN1_MISSING_EOC;
    return 0;
}

#define get_eoc()                               \
    {                                           \
        retval = asn1_get_eoc_tag(&subbuf);     \
        if (retval) clean_return(retval);       \
    }

/* decode sequence header and initialize tagnum with the first field */
#define begin_structure()                                       \
    unsigned int taglen;                                        \
    asn1buf subbuf;                                             \
    int seqindef;                                               \
    int indef;                                                  \
    retval = asn1_get_sequence(&buf,&length,&seqindef);         \
    if (retval) clean_return(retval);                           \
    retval = asn1buf_imbed(&subbuf,&buf,length,seqindef);       \
    if (retval) clean_return(retval);                           \
    next_tag()

#define end_structure()                                         \
    retval = asn1buf_sync(&buf,&subbuf,asn1class,               \
                          tagnum,length,indef,seqindef);        \
    if (retval) clean_return(retval)

/* process fields *******************************************/
/* normal fields ************************/
#define get_field_body(var,decoder)             \
    retval = decoder(&subbuf,&(var));           \
    if (retval) clean_return(retval);           \
    if (indef) { get_eoc(); }                   \
    next_tag()

/*
 * error_if_bad_tag
 *
 * Checks that the next tag is the expected one; returns with an error
 * if not.
 */
#define error_if_bad_tag(tagexpect)                                     \
    if (tagnum != (tagexpect)) { clean_return ((tagnum < (tagexpect)) ? ASN1_MISPLACED_FIELD : ASN1_MISSING_FIELD); }

/*
 * decode a field (<[UNIVERSAL id]> <length> <contents>)
 *  check that the id number == tagexpect then
 *  decode into var
 *  get the next tag
 */
#define get_field(var,tagexpect,decoder)                                \
    error_if_bad_tag(tagexpect);                                        \
    if (asn1class != CONTEXT_SPECIFIC || construction != CONSTRUCTED)   \
        clean_return(ASN1_BAD_ID);                                      \
    get_field_body(var,decoder)

/* decode (or skip, if not present) an optional field */
#define opt_field(var,tagexpect,decoder)                                \
    if (asn1buf_remains(&subbuf, seqindef)) {                           \
        if (asn1class != CONTEXT_SPECIFIC || construction != CONSTRUCTED) \
            clean_return(ASN1_BAD_ID);                                  \
        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);           \
    if (indef) { get_eoc(); }                   \
    next_tag()

/* decode a field w/ its length (for string types) */
#define get_lenfield(len,var,tagexpect,decoder)                         \
    error_if_bad_tag(tagexpect);                                        \
    if (asn1class != CONTEXT_SPECIFIC || construction != CONSTRUCTED)   \
        clean_return(ASN1_BAD_ID);                                      \
    get_lenfield_body(len,var,decoder)

/* decode an optional field w/ length */
#define opt_lenfield(len,var,tagexpect,decoder)                         \
    if (asn1buf_remains(&subbuf, seqindef)) {                           \
        if (asn1class != CONTEXT_SPECIFIC || construction != CONSTRUCTED) \
            clean_return(ASN1_BAD_ID);                                  \
        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)                \
    *repptr = rep;                              \
    return 0;                                   \
error_out:                                      \
if (rep)                                        \
    cleanup_routine(rep);                       \
return retval;

#define cleanup_none()                          \
    *repptr = rep;                              \
    return 0;                                   \
error_out:                                      \
return retval;

#define cleanup_manual()                        \
    *repptr = rep;                              \
    return 0;

#define free_field(rep,f) free((rep)->f)
#define clear_field(rep,f) (rep)->f = 0

#ifndef LEAN_CLIENT
krb5_error_code
decode_krb5_authenticator(const krb5_data *code, krb5_authenticator **repptr)
{
    setup(krb5_authenticator *);
    alloc_field(rep);
    clear_field(rep,subkey);
    clear_field(rep,checksum);
    clear_field(rep,client);
    clear_field(rep,authorization_data);

    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_principal(rep->client);
        get_field(rep->client,1,asn1_decode_realm);
        get_field(rep->client,2,asn1_decode_principal_name);
        opt_field(rep->checksum,3,asn1_decode_checksum_ptr);
        get_field(rep->cusec,4,asn1_decode_int32);
        get_field(rep->ctime,5,asn1_decode_kerberos_time);
        opt_field(rep->subkey,6,asn1_decode_encryption_key_ptr);
        opt_field(rep->seq_number,7,asn1_decode_seqnum);
        opt_field(rep->authorization_data,8,asn1_decode_authorization_data);
        rep->magic = KV5M_AUTHENTICATOR;
        end_structure();
    }
    cleanup_manual();
error_out:
    krb5_free_authenticator(NULL, rep);
    return retval;
}
#endif

krb5_error_code KRB5_CALLCONV
krb5_decode_ticket(const krb5_data *code, krb5_ticket **repptr)
{
    return decode_krb5_ticket(code, repptr);
}

krb5_error_code
decode_krb5_ticket(const krb5_data *code, krb5_ticket **repptr)
{
    setup(krb5_ticket *);
    alloc_field(rep);
    clear_field(rep,server);
    clear_field(rep,enc_part.ciphertext.data);
    clear_field(rep,enc_part2);

    check_apptag(1);
    { begin_structure();
        { krb5_kvno kvno;
            get_field(kvno,0,asn1_decode_kvno);
            if (kvno != KVNO) clean_return(KRB5KDC_ERR_BAD_PVNO);
        }
        alloc_principal(rep->server);
        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);
        rep->magic = KV5M_TICKET;
        end_structure();
    }
    cleanup_manual();
error_out:
    krb5_free_ticket(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_encryption_key(const krb5_data *code, krb5_keyblock **repptr)
{
    setup(krb5_keyblock *);
    alloc_field(rep);
    clear_field(rep,contents);

    { 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_manual();
error_out:
    krb5_free_keyblock(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_enc_tkt_part(const krb5_data *code, krb5_enc_tkt_part **repptr)
{
    setup(krb5_enc_tkt_part *);
    alloc_field(rep);
    clear_field(rep,session);
    clear_field(rep,client);
    clear_field(rep,transited.tr_contents.data);
    clear_field(rep,caddrs);
    clear_field(rep,authorization_data);

    check_apptag(3);
    { begin_structure();
        get_field(rep->flags,0,asn1_decode_ticket_flags);
        get_field(rep->session,1,asn1_decode_encryption_key_ptr);
        alloc_principal(rep->client);
        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);
        if (tagnum == 6)
        { get_field(rep->times.starttime,6,asn1_decode_kerberos_time); }
        else
            rep->times.starttime=rep->times.authtime;
        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);
        rep->magic = KV5M_ENC_TKT_PART;
        end_structure();
    }
    cleanup_manual();
error_out:
    krb5_free_enc_tkt_part(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_enc_kdc_rep_part(const krb5_data *code,
                             krb5_enc_kdc_rep_part **repptr)
{
    taginfo t4;
    setup_buf_only(krb5_enc_kdc_rep_part *);
    alloc_field(rep);

    retval = asn1_get_tag_2(&buf, &t4);
    if (retval) clean_return(retval);
    if (t4.asn1class != APPLICATION || t4.construction != CONSTRUCTED) clean_return(ASN1_BAD_ID);
    if (t4.tagnum == 25) rep->msg_type = KRB5_AS_REP;
    else if (t4.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(const krb5_data *code, krb5_kdc_rep **repptr)
{
    setup_no_length(krb5_kdc_rep *);
    alloc_field(rep);
    clear_field(rep,padata);
    clear_field(rep,client);
    clear_field(rep,ticket);
    clear_field(rep,enc_part.ciphertext.data);
    clear_field(rep,enc_part2);

    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_manual();
error_out:
    krb5_free_kdc_rep(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_tgs_rep(const krb5_data *code, krb5_kdc_rep **repptr)
{
    setup_no_length(krb5_kdc_rep *);
    alloc_field(rep);
    clear_field(rep,padata);
    clear_field(rep,client);
    clear_field(rep,ticket);
    clear_field(rep,enc_part.ciphertext.data);
    clear_field(rep,enc_part2);

    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_manual();
error_out:
    krb5_free_kdc_rep(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_ap_req(const krb5_data *code, krb5_ap_req **repptr)
{
    setup(krb5_ap_req *);
    alloc_field(rep);
    clear_field(rep,ticket);
    clear_field(rep,authenticator.ciphertext.data);

    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);
        get_field(rep->ticket,3,asn1_decode_ticket_ptr);
        get_field(rep->authenticator,4,asn1_decode_encrypted_data);
        end_structure();
        rep->magic = KV5M_AP_REQ;
    }
    cleanup_manual();
error_out:
    krb5_free_ap_req(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_ap_rep(const krb5_data *code, krb5_ap_rep **repptr)
{
    setup(krb5_ap_rep *);
    alloc_field(rep);
    clear_field(rep,enc_part.ciphertext.data);

    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();
        rep->magic = KV5M_AP_REP;
    }
    cleanup_manual();
error_out:
    krb5_free_ap_rep(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_ap_rep_enc_part(const krb5_data *code,
                            krb5_ap_rep_enc_part **repptr)
{
    setup(krb5_ap_rep_enc_part *);
    alloc_field(rep);
    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);
        opt_field(rep->subkey,2,asn1_decode_encryption_key_ptr);
        opt_field(rep->seq_number,3,asn1_decode_seqnum);
        end_structure();
        rep->magic = KV5M_AP_REP_ENC_PART;
    }
    cleanup_manual();
error_out:
    krb5_free_ap_rep_enc_part(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_as_req(const krb5_data *code, krb5_kdc_req **repptr)
{
    setup_no_length(krb5_kdc_req *);
    alloc_field(rep);
    clear_field(rep,padata);
    clear_field(rep,client);
    clear_field(rep,server);
    clear_field(rep,ktype);
    clear_field(rep,addresses);
    clear_field(rep,authorization_data.ciphertext.data);
    clear_field(rep,unenc_authdata);
    clear_field(rep,second_ticket);
    clear_field(rep, kdc_state);

    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_manual();
error_out:
    krb5_free_kdc_req(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_tgs_req(const krb5_data *code, krb5_kdc_req **repptr)
{
    setup_no_length(krb5_kdc_req *);
    alloc_field(rep);
    clear_field(rep,padata);
    clear_field(rep,client);
    clear_field(rep,server);
    clear_field(rep,ktype);
    clear_field(rep,addresses);
    clear_field(rep,authorization_data.ciphertext.data);
    clear_field(rep,unenc_authdata);
    clear_field(rep,second_ticket);
    clear_field(rep, kdc_state);

    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_manual();
error_out:
    krb5_free_kdc_req(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_kdc_req_body(const krb5_data *code, krb5_kdc_req **repptr)
{
    setup_buf_only(krb5_kdc_req *);
    alloc_field(rep);

    retval = asn1_decode_kdc_req_body(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

/*
 * decode_krb5_safe_with_body
 *
 * Like decode_krb5_safe(), but grabs the encoding of the
 * KRB-SAFE-BODY as well, in case re-encoding would produce a
 * different encoding.  (Yes, we're using DER, but there's this
 * annoying problem with pre-1.3.x code using signed sequence numbers,
 * which we permissively decode and cram into unsigned 32-bit numbers.
 * When they're re-encoded, they're no longer negative if they started
 * out negative, so checksum verification fails.)
 *
 * This does *not* perform any copying; the returned pointer to the
 * encoded KRB-SAFE-BODY points into the input buffer.
 */
krb5_error_code
decode_krb5_safe_with_body(const krb5_data *code, krb5_safe **repptr,
                           krb5_data *body)
{
    krb5_data tmpbody;
    setup(krb5_safe *);
    alloc_field(rep);
    clear_field(rep,user_data.data);
    clear_field(rep,r_address);
    clear_field(rep,s_address);
    clear_field(rep,checksum);
    tmpbody.magic = 0;

    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
        }
        /*
         * Gross kludge to extract pointer to encoded safe-body.  Relies
         * on tag prefetch done by next_tag().  Don't handle indefinite
         * encoding, as it's too much work.
         */
        if (!indef) {
            tmpbody.length = taglen;
            tmpbody.data = subbuf.next;
        } else {
            tmpbody.length = 0;
            tmpbody.data = NULL;
        }
        get_field(*rep,2,asn1_decode_krb_safe_body);
        get_field(rep->checksum,3,asn1_decode_checksum_ptr);
        rep->magic = KV5M_SAFE;
        end_structure();
    }
    if (body != NULL)
        *body = tmpbody;
    cleanup_manual();
error_out:
    krb5_free_safe(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_safe(const krb5_data *code, krb5_safe **repptr)
{
    return decode_krb5_safe_with_body(code, repptr, NULL);
}

krb5_error_code
decode_krb5_priv(const krb5_data *code, krb5_priv **repptr)
{
    setup(krb5_priv *);
    alloc_field(rep);
    clear_field(rep,enc_part.ciphertext.data);

    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);
        rep->magic = KV5M_PRIV;
        end_structure();
    }
    cleanup_manual();
error_out:
    krb5_free_priv(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_enc_priv_part(const krb5_data *code, krb5_priv_enc_part **repptr)
{
    setup(krb5_priv_enc_part *);
    alloc_field(rep);
    clear_field(rep,user_data.data);
    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_seqnum);
        get_field(rep->s_address,4,asn1_decode_host_address_ptr);
        opt_field(rep->r_address,5,asn1_decode_host_address_ptr);
        rep->magic = KV5M_PRIV_ENC_PART;
        end_structure();
    }
    cleanup_manual();
error_out:
    krb5_free_priv_enc_part(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_cred(const krb5_data *code, krb5_cred **repptr)
{
    setup(krb5_cred *);
    alloc_field(rep);
    clear_field(rep,tickets);
    clear_field(rep,enc_part.ciphertext.data);

    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);
        rep->magic = KV5M_CRED;
        end_structure();
    }
    cleanup_manual();
error_out:
    krb5_free_cred(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_enc_cred_part(const krb5_data *code, krb5_cred_enc_part **repptr)
{
    setup(krb5_cred_enc_part *);
    alloc_field(rep);
    clear_field(rep,r_address);
    clear_field(rep,s_address);
    clear_field(rep,ticket_info);

    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);
        opt_field(rep->s_address,4,asn1_decode_host_address_ptr);
        opt_field(rep->r_address,5,asn1_decode_host_address_ptr);
        rep->magic = KV5M_CRED_ENC_PART;
        end_structure();
    }
    cleanup_manual();
error_out:
    /* Despite the name, krb5_free_cred_enc_part is contents only. */
    krb5_free_cred_enc_part(NULL, rep);
    free(rep);
    return retval;
}


krb5_error_code
decode_krb5_error(const krb5_data *code, krb5_error **repptr)
{
    setup(krb5_error *);
    alloc_field(rep);
    clear_field(rep,server);
    clear_field(rep,client);
    clear_field(rep,text.data);
    clear_field(rep,e_data.data);

    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_principal(rep->client); }
        opt_field(rep->client,7,asn1_decode_realm);
        opt_field(rep->client,8,asn1_decode_principal_name);
        alloc_principal(rep->server);
        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);
        rep->magic = KV5M_ERROR;
        end_structure();
    }
    cleanup_manual();
error_out:
    krb5_free_error(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_authdata(const krb5_data *code, krb5_authdata ***repptr)
{
    setup_buf_only(krb5_authdata **);
    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(const krb5_data *code, passwd_phrase_element **repptr)
{
    setup_buf_only(passwd_phrase_element *);
    alloc_field(rep);
    retval = asn1_decode_passwdsequence(&buf,rep);
    if (retval) clean_return(retval);
    cleanup(free);
}

krb5_error_code
decode_krb5_pwd_data(const krb5_data *code, krb5_pwd_data **repptr)
{
    setup(krb5_pwd_data *);
    alloc_field(rep);
    clear_field(rep,element);
    { begin_structure();
        get_field(rep->sequence_count,0,asn1_decode_int);
        get_field(rep->element,1,asn1_decode_sequence_of_passwdsequence);
        rep->magic = KV5M_PWD_DATA;
        end_structure (); }
    cleanup_manual();
error_out:
    krb5_free_pwd_data(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_padata_sequence(const krb5_data *code, krb5_pa_data ***repptr)
{
    setup_buf_only(krb5_pa_data **);
    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(const krb5_data *code, krb5_alt_method **repptr)
{
    setup(krb5_alt_method *);
    alloc_field(rep);
    clear_field(rep,data);
    { 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_manual();
error_out:
    krb5_free_alt_method(NULL, rep);
    return retval;
}

krb5_error_code
decode_krb5_etype_info(const krb5_data *code, krb5_etype_info_entry ***repptr)
{
    setup_buf_only(krb5_etype_info_entry **);
    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_etype_info2(const krb5_data *code, krb5_etype_info_entry ***repptr)
{
    setup_buf_only(krb5_etype_info_entry **);
    retval = asn1_decode_etype_info2(&buf,&rep, 0);
    if (retval == ASN1_BAD_ID) {
        retval = asn1buf_wrap_data(&buf,code);
        if (retval) clean_return(retval);
        retval = asn1_decode_etype_info2(&buf, &rep, 1);
    }
    if (retval) clean_return(retval);
    cleanup_none();             /* we're not allocating anything here */
}


krb5_error_code
decode_krb5_enc_data(const krb5_data *code, krb5_enc_data **repptr)
{
    setup_buf_only(krb5_enc_data *);
    alloc_field(rep);

    retval = asn1_decode_encrypted_data(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_pa_enc_ts(const krb5_data *code, krb5_pa_enc_ts **repptr)
{
    setup(krb5_pa_enc_ts *);
    alloc_field(rep);
    { begin_structure();
        get_field(rep->patimestamp,0,asn1_decode_kerberos_time);
        if (tagnum == 1) {
            get_field(rep->pausec,1,asn1_decode_int32);
        } else
            rep->pausec = 0;
        end_structure (); }
    cleanup(free);
}

krb5_error_code
decode_krb5_sam_challenge(const krb5_data *code, krb5_sam_challenge **repptr)
{
    setup_buf_only(krb5_sam_challenge *);
    alloc_field(rep);

    retval = asn1_decode_sam_challenge(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_sam_challenge_2(const krb5_data *code,
                            krb5_sam_challenge_2 **repptr)
{
    setup_buf_only(krb5_sam_challenge_2 *);
    alloc_field(rep);

    retval = asn1_decode_sam_challenge_2(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_sam_challenge_2_body(const krb5_data *code,
                                 krb5_sam_challenge_2_body **repptr)
{
    setup_buf_only(krb5_sam_challenge_2_body *);
    alloc_field(rep);

    retval = asn1_decode_sam_challenge_2_body(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_enc_sam_key(const krb5_data *code, krb5_sam_key **repptr)
{
    setup_buf_only(krb5_sam_key *);
    alloc_field(rep);

    retval = asn1_decode_enc_sam_key(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_enc_sam_response_enc(const krb5_data *code,
                                 krb5_enc_sam_response_enc **repptr)
{
    setup_buf_only(krb5_enc_sam_response_enc *);
    alloc_field(rep);

    retval = asn1_decode_enc_sam_response_enc(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_enc_sam_response_enc_2(const krb5_data *code,
                                   krb5_enc_sam_response_enc_2 **repptr)
{
    setup_buf_only(krb5_enc_sam_response_enc_2 *);
    alloc_field(rep);

    retval = asn1_decode_enc_sam_response_enc_2(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_sam_response(const krb5_data *code,
                         krb5_sam_response **repptr)
{
    setup_buf_only(krb5_sam_response *);
    alloc_field(rep);

    retval = asn1_decode_sam_response(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_sam_response_2(const krb5_data *code,
                           krb5_sam_response_2 **repptr)
{
    setup_buf_only(krb5_sam_response_2 *);
    alloc_field(rep);

    retval = asn1_decode_sam_response_2(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_predicted_sam_response(const krb5_data *code,
                                   krb5_predicted_sam_response **repptr)
{
    setup_buf_only(krb5_predicted_sam_response *);           /* preallocated */
    alloc_field(rep);

    retval = asn1_decode_predicted_sam_response(&buf,rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_setpw_req(const krb5_data *code, krb5_data **repptr,
                      krb5_principal *principal)
{
    setup_buf_only(krb5_data *);
    alloc_field(rep);
    *principal = NULL;

    retval = asn1_decode_setpw_req(&buf, rep, principal);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_pa_for_user(const krb5_data *code, krb5_pa_for_user **repptr)
{
    setup_buf_only(krb5_pa_for_user *);
    alloc_field(rep);

    retval = asn1_decode_pa_for_user(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_pa_s4u_x509_user(const krb5_data *code, krb5_pa_s4u_x509_user **repptr)
{
    setup_buf_only(krb5_pa_s4u_x509_user *);
    alloc_field(rep);

    retval = asn1_decode_pa_s4u_x509_user(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_pa_pac_req(const krb5_data *code, krb5_pa_pac_req **repptr)
{
    setup_buf_only(krb5_pa_pac_req *);
    alloc_field(rep);

    retval = asn1_decode_pa_pac_req(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_etype_list(const krb5_data *code, krb5_etype_list **repptr)
{
    setup_buf_only(krb5_etype_list *);
    alloc_field(rep);

    retval = asn1_decode_sequence_of_enctype(&buf, &rep->length, &rep->etypes);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code decode_krb5_pa_fx_fast_request
(const krb5_data *code, krb5_fast_armored_req **repptr)
{
    setup(krb5_fast_armored_req *);
    alloc_field(rep);
    clear_field(rep, armor);
    {
        int indef;
        unsigned int taglen;
        next_tag_from_buf(buf);
        if (tagnum != 0)
            clean_return(ASN1_BAD_ID);
    }
    {begin_structure();
        opt_field(rep->armor, 0, asn1_decode_fast_armor_ptr);
        get_field(rep->req_checksum, 1, asn1_decode_checksum);
        get_field(rep->enc_part, 2, asn1_decode_encrypted_data);
        end_structure();}
    rep->magic = KV5M_FAST_ARMORED_REQ;
    cleanup(free);
}

krb5_error_code decode_krb5_fast_req
(const krb5_data *code, krb5_fast_req **repptr)
{
    setup(krb5_fast_req *);
    alloc_field(rep);
    alloc_field(rep->req_body);
    clear_field(rep, req_body->padata);
    {begin_structure();
        get_field(rep->fast_options, 0, asn1_decode_krb5_flags);
        opt_field(rep->req_body->padata, 1, asn1_decode_sequence_of_pa_data);
        get_field(*(rep->req_body), 2, asn1_decode_kdc_req_body);
        end_structure(); }
    rep->magic  = KV5M_FAST_REQ;
    cleanup_manual();
error_out:
    if (rep) {
        if (rep->req_body)
            krb5_free_kdc_req(0, rep->req_body);
        free(rep);
    }
    return retval;
}

krb5_error_code decode_krb5_fast_response
(const krb5_data *code, krb5_fast_response **repptr)
{
    setup(krb5_fast_response *);

    alloc_field(rep);
    clear_field(rep, finished);
    clear_field(rep, padata);
    clear_field(rep,strengthen_key);
    {begin_structure();
        get_field(rep->padata, 0, asn1_decode_sequence_of_pa_data);
        opt_field(rep->strengthen_key, 1, asn1_decode_encryption_key_ptr);
        opt_field(rep->finished, 2, asn1_decode_fast_finished_ptr);
        get_field(rep->nonce, 3, asn1_decode_int32);
        end_structure(); }
    rep->magic = KV5M_FAST_RESPONSE;
    cleanup(free);
}

krb5_error_code decode_krb5_pa_fx_fast_reply
(const krb5_data *code, krb5_enc_data **repptr)
{
    setup(krb5_enc_data *);
    alloc_field(rep);
    {
        int indef;
        unsigned int taglen;
        next_tag_from_buf(buf);
        if (tagnum != 0)
            clean_return(ASN1_BAD_ID);
    }
    {begin_structure();
        get_field(*rep, 0, asn1_decode_encrypted_data);
        end_structure();
    }

    cleanup(free);
}

krb5_error_code
decode_krb5_ad_kdcissued(const krb5_data *code, krb5_ad_kdcissued **repptr)
{
    setup_buf_only(krb5_ad_kdcissued *);
    alloc_field(rep);

    retval = asn1_decode_ad_kdcissued(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_ad_signedpath(const krb5_data *code, krb5_ad_signedpath **repptr)
{
    setup_buf_only(krb5_ad_signedpath *);
    alloc_field(rep);

    retval = asn1_decode_ad_signedpath(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
krb5int_get_authdata_containee_types(krb5_context context,
                                     const krb5_authdata *authdata,
                                     unsigned int *num,
                                     krb5_authdatatype **repptr)
{
    krb5_data data, *code = &data;

    data.data = (char *)authdata->contents;
    data.length = authdata->length;

    *num = 0;

    {
        setup_buf_only(krb5_authdatatype *);

        retval = asn1_peek_authorization_data(&buf, num, &rep);
        if (retval) clean_return(retval);

        cleanup_none();
    }
    assert(0); /* NOTREACHED */
}

#ifndef DISABLE_PKINIT
krb5_error_code
decode_krb5_pa_pk_as_req(const krb5_data *code, krb5_pa_pk_as_req **repptr)
{
    setup_buf_only(krb5_pa_pk_as_req *);
    alloc_field(rep);

    retval = asn1_decode_pa_pk_as_req(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_pa_pk_as_req_draft9(const krb5_data *code,
                                krb5_pa_pk_as_req_draft9 **repptr)
{
    setup_buf_only(krb5_pa_pk_as_req_draft9 *);
    alloc_field(rep);

    retval = asn1_decode_pa_pk_as_req_draft9(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_pa_pk_as_rep(const krb5_data *code, krb5_pa_pk_as_rep **repptr)
{
    setup_buf_only(krb5_pa_pk_as_rep *);
    alloc_field(rep);

    retval = asn1_decode_pa_pk_as_rep(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_pa_pk_as_rep_draft9(const krb5_data *code,
                                krb5_pa_pk_as_rep_draft9 **repptr)
{
    setup_buf_only(krb5_pa_pk_as_rep_draft9 *);
    alloc_field(rep);

    retval = asn1_decode_pa_pk_as_rep_draft9(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_auth_pack(const krb5_data *code, krb5_auth_pack **repptr)
{
    setup_buf_only(krb5_auth_pack *);
    alloc_field(rep);

    retval = asn1_decode_auth_pack(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_auth_pack_draft9(const krb5_data *code,
                             krb5_auth_pack_draft9 **repptr)
{
    setup_buf_only(krb5_auth_pack_draft9 *);
    alloc_field(rep);

    retval = asn1_decode_auth_pack_draft9(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_kdc_dh_key_info(const krb5_data *code,
                            krb5_kdc_dh_key_info **repptr)
{
    setup_buf_only(krb5_kdc_dh_key_info *);
    alloc_field(rep);

    retval = asn1_decode_kdc_dh_key_info(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_principal_name(const krb5_data *code, krb5_principal_data **repptr)
{
    setup_buf_only(krb5_principal_data *);
    alloc_field(rep);

    retval = asn1_decode_krb5_principal_name(&buf, &rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_reply_key_pack(const krb5_data *code, krb5_reply_key_pack **repptr)
{
    setup_buf_only(krb5_reply_key_pack *);
    alloc_field(rep);

    retval = asn1_decode_reply_key_pack(&buf, rep);
    if (retval)
        goto error_out;

    cleanup(free);
}

krb5_error_code
decode_krb5_reply_key_pack_draft9(const krb5_data *code,
                                  krb5_reply_key_pack_draft9 **repptr)
{
    setup_buf_only(krb5_reply_key_pack_draft9 *);
    alloc_field(rep);

    retval = asn1_decode_reply_key_pack_draft9(&buf, rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_td_trusted_certifiers(const krb5_data *code,
                                  krb5_external_principal_identifier ***repptr)
{
    setup_buf_only(krb5_external_principal_identifier **);
    retval = asn1_decode_sequence_of_external_principal_identifier(&buf, &rep);
    if (retval) clean_return(retval);

    cleanup(free);
}

krb5_error_code
decode_krb5_td_dh_parameters(const krb5_data *code,
                             krb5_algorithm_identifier ***repptr)
{
    setup_buf_only(krb5_algorithm_identifier **);
    retval = asn1_decode_sequence_of_algorithm_identifier(&buf, &rep);
    if (retval) clean_return(retval);

    cleanup(free);
}
#endif /* DISABLE_PKINIT */

krb5_error_code
decode_krb5_typed_data(const krb5_data *code, krb5_typed_data ***repptr)
{
    setup_buf_only(krb5_typed_data **);
    retval = asn1_decode_sequence_of_typed_data(&buf, &rep);
    if (retval) clean_return(retval);

    cleanup(free);
}