boolean ber_read_integer(STREAM* s, uint32* value)
{
int length;
ber_read_universal_tag(s, BER_TAG_INTEGER, false);
ber_read_length(s, &length);
if (value == NULL)
{
stream_seek(s, length);
return true;
}
if (length == 1)
stream_read_uint8(s, *value);
else if (length == 2)
stream_read_uint16_be(s, *value);
else if (length == 3)
{
uint8 byte;
stream_read_uint8(s, byte);
stream_read_uint16_be(s, *value);
*value += (byte << 16);
}
else if (length == 4)
stream_read_uint32_be(s, *value);
else
return false;
return true;
}
int krb_tgsrep_recv(KRB_CONTEXT* krb_ctx)
{
int totlen, tmp, len;
int errcode;
STREAM* s;
KrbTGSREP* krb_tgsrep;
KrbKDCREP* kdc_rep;
errcode = -1;
s = stream_new(2048);
krb_tcp_recv(krb_ctx, s->data, s->size);
stream_read_uint32_be(s, totlen);
if(totlen >= 2044) // MALFORMED PACKET
goto finish;
if(((len = krb_decode_application_tag(s, KRB_TAG_TGSREP, &tmp)) == 0) || (tmp != (totlen - len))) //NOT AN TGS-REP
{
krb_ctx->state = KRB_PACKET_ERROR;
goto finish;
}
else /* TGS-REP process */
{
totlen -= len;
krb_tgsrep = xnew(KrbTGSREP);
krb_ctx->tgskey = xnew(KrbENCKey);
if(krb_decode_kdc_rep(s, &(krb_tgsrep->kdc_rep), totlen) == 0)
{
krb_ctx->state = KRB_PACKET_ERROR;
goto finish;
}
kdc_rep = &(krb_tgsrep->kdc_rep);
if(krb_verify_kdcrep(krb_ctx, kdc_rep, KRB_TAG_TGSREP) == 0)
krb_ctx->state = KRB_TGSREP_OK;
else
krb_ctx->state = KRB_PACKET_ERROR;
/* clean up */
krb_free_tgsrep(krb_tgsrep);
xfree(krb_tgsrep);
goto finish;
}
finish:
stream_free(s);
return errcode;
}
int krb_asrep_recv(KRB_CONTEXT* krb_ctx)
{
int totlen, tmp, len;
int errcode;
STREAM* s;
KrbERROR* krb_err;
KrbASREP* krb_asrep;
KrbKDCREP* kdc_rep;
errcode = -1;
s = stream_new(2048);
krb_tcp_recv(krb_ctx, s->data, s->size);
stream_read_uint32_be(s, totlen);
if(totlen >= 2044) // MALFORMED PACKET
goto finish;
if(((len = krb_decode_application_tag(s, KRB_TAG_ASREP, &tmp)) == 0) || (tmp != (totlen - len))) //NOT AN AS-REP
{
if(((len = krb_decode_application_tag(s, KRB_TAG_ERROR, &tmp)) == 0) || (tmp != (totlen - len))) // NOT AN KRB-ERROR
{
krb_ctx->state = KRB_PACKET_ERROR;
goto finish;
}
else
{
totlen -= len;
krb_err = xnew(KrbERROR);
if((totlen <= 0) || ((len = krb_decode_krb_error(s, krb_err, totlen)) == 0))
{
krb_ctx->state = KRB_PACKET_ERROR;
xfree(krb_err);
goto finish;
}
/* ERROR CODE */
errcode = krb_err->errcode;
if(errcode == KRB_AP_ERR_SKEW)
{
krb_ctx->state = KRB_ASREP_ERR;
goto errclean;
}
else if(errcode == KDC_ERR_PREAUTH_REQ)
{
/* should parse PA-ENC-TYPE-INFO2 */
krb_ctx->state = KRB_ASREP_ERR;
goto errclean;
}
else if(errcode == KDC_ERR_C_PRINCIPAL_UNKNOWN)
{
printf("KDC_ERR_C_PRINCIPAL_UNKNOWN\n");
krb_ctx->state = KRB_ASREP_ERR;
goto errclean;
}
else
{
krb_ctx->state = KRB_PACKET_ERROR;
goto errclean;
}
errclean:
krb_free_krb_error(krb_err);
xfree(krb_err);
goto finish;
}
}
else /* AS-REP process */
{
totlen -= len;
krb_asrep = xnew(KrbASREP);
if(krb_decode_kdc_rep(s, &(krb_asrep->kdc_rep), totlen) == 0)
{
krb_ctx->state = KRB_PACKET_ERROR;
goto finish;
}
kdc_rep = &(krb_asrep->kdc_rep);
if(krb_verify_kdcrep(krb_ctx, kdc_rep, KRB_TAG_ASREP) == 0)
krb_ctx->state = KRB_ASREP_OK;
else
krb_ctx->state = KRB_PACKET_ERROR;
/* clean up */
krb_free_asrep(krb_asrep);
xfree(krb_asrep);
goto finish;
}
finish:
stream_free(s);
return errcode;
}
