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#include <string.h>
#include "k5-int.h"
#include "krb5_err.h"
#include "auth_con.h"
krb5_error_code KRB5_CALLCONV
krb5_mk_chpw_req(krb5_context context, krb5_auth_context auth_context, krb5_data *ap_req, char *passwd, krb5_data *packet)
{
krb5_error_code ret = 0;
krb5_data clearpw;
krb5_data cipherpw;
krb5_replay_data replay;
char *ptr;
cipherpw.data = NULL;
if ((ret = krb5_auth_con_setflags(context, auth_context,
KRB5_AUTH_CONTEXT_DO_SEQUENCE)))
goto cleanup;
clearpw.length = strlen(passwd);
clearpw.data = passwd;
if ((ret = krb5_mk_priv(context, auth_context,
&clearpw, &cipherpw, &replay)))
goto cleanup;
packet->length = 6 + ap_req->length + cipherpw.length;
packet->data = (char *) malloc(packet->length);
if (packet->data == NULL)
{
ret = ENOMEM;
goto cleanup;
}
ptr = packet->data;
/* length */
*ptr++ = (packet->length>>8) & 0xff;
*ptr++ = packet->length & 0xff;
/* version == 0x0001 big-endian */
*ptr++ = 0;
*ptr++ = 1;
/* ap_req length, big-endian */
*ptr++ = (ap_req->length>>8) & 0xff;
*ptr++ = ap_req->length & 0xff;
/* ap-req data */
memcpy(ptr, ap_req->data, ap_req->length);
ptr += ap_req->length;
/* krb-priv of password */
memcpy(ptr, cipherpw.data, cipherpw.length);
cleanup:
if(cipherpw.data != NULL) /* allocated by krb5_mk_priv */
free(cipherpw.data);
return(ret);
}
krb5_error_code KRB5_CALLCONV
krb5_rd_chpw_rep(krb5_context context, krb5_auth_context auth_context, krb5_data *packet, int *result_code, krb5_data *result_data)
{
char *ptr;
int plen, vno;
krb5_data ap_rep;
krb5_ap_rep_enc_part *ap_rep_enc;
krb5_error_code ret;
krb5_data cipherresult;
krb5_data clearresult;
krb5_error *krberror;
krb5_replay_data replay;
krb5_keyblock *tmp;
if (packet->length < 4)
/* either this, or the server is printing bad messages,
or the caller passed in garbage */
return(KRB5KRB_AP_ERR_MODIFIED);
ptr = packet->data;
/* verify length */
plen = (*ptr++ & 0xff);
plen = (plen<<8) | (*ptr++ & 0xff);
if (plen != packet->length)
return(KRB5KRB_AP_ERR_MODIFIED);
/* verify version number */
vno = (*ptr++ & 0xff);
vno = (vno<<8) | (*ptr++ & 0xff);
if (vno != 1)
return(KRB5KDC_ERR_BAD_PVNO);
/* read, check ap-rep length */
ap_rep.length = (*ptr++ & 0xff);
ap_rep.length = (ap_rep.length<<8) | (*ptr++ & 0xff);
if (ptr + ap_rep.length >= packet->data + packet->length)
return(KRB5KRB_AP_ERR_MODIFIED);
if (ap_rep.length) {
/* verify ap_rep */
ap_rep.data = ptr;
ptr += ap_rep.length;
if ((ret = krb5_rd_rep(context, auth_context, &ap_rep, &ap_rep_enc)))
return(ret);
krb5_free_ap_rep_enc_part(context, ap_rep_enc);
/* extract and decrypt the result */
cipherresult.data = ptr;
cipherresult.length = (packet->data + packet->length) - ptr;
/* XXX there's no api to do this right. The problem is that
if there's a remote subkey, it will be used. This is
not what the spec requires */
tmp = auth_context->remote_subkey;
auth_context->remote_subkey = NULL;
ret = krb5_rd_priv(context, auth_context, &cipherresult, &clearresult,
&replay);
auth_context->remote_subkey = tmp;
if (ret)
return(ret);
} else {
cipherresult.data = ptr;
cipherresult.length = (packet->data + packet->length) - ptr;
if ((ret = krb5_rd_error(context, &cipherresult, &krberror)))
return(ret);
clearresult = krberror->e_data;
}
if (clearresult.length < 2) {
ret = KRB5KRB_AP_ERR_MODIFIED;
goto cleanup;
}
ptr = clearresult.data;
*result_code = (*ptr++ & 0xff);
*result_code = (*result_code<<8) | (*ptr++ & 0xff);
if ((*result_code < KRB5_KPASSWD_SUCCESS) ||
(*result_code > KRB5_KPASSWD_SOFTERROR)) {
ret = KRB5KRB_AP_ERR_MODIFIED;
goto cleanup;
}
/* all success replies should be authenticated/encrypted */
if ((ap_rep.length == 0) && (*result_code == KRB5_KPASSWD_SUCCESS)) {
ret = KRB5KRB_AP_ERR_MODIFIED;
goto cleanup;
}
result_data->length = (clearresult.data + clearresult.length) - ptr;
if (result_data->length) {
result_data->data = (char *) malloc(result_data->length);
if (result_data->data == NULL) {
ret = ENOMEM;
goto cleanup;
}
memcpy(result_data->data, ptr, result_data->length);
} else {
result_data->data = NULL;
}
ret = 0;
cleanup:
if (ap_rep.length) {
krb5_xfree(clearresult.data);
} else {
krb5_free_error(context, krberror);
}
return(ret);
}
krb5_error_code KRB5_CALLCONV
krb5_chpw_result_code_string(krb5_context context, int result_code, char **code_string)
{
switch (result_code) {
case KRB5_KPASSWD_MALFORMED:
*code_string = "Malformed request error";
break;
case KRB5_KPASSWD_HARDERROR:
*code_string = "Server error";
break;
case KRB5_KPASSWD_AUTHERROR:
*code_string = "Authentication error";
break;
case KRB5_KPASSWD_SOFTERROR:
*code_string = "Password change rejected";
break;
default:
*code_string = "Password change failed";
break;
}
return(0);
}
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