diff options
Diffstat (limited to 'third_party/heimdal/lib/krb5/rd_safe.c')
| -rw-r--r-- | third_party/heimdal/lib/krb5/rd_safe.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/krb5/rd_safe.c b/third_party/heimdal/lib/krb5/rd_safe.c new file mode 100644 index 0000000..24ed636 --- /dev/null +++ b/third_party/heimdal/lib/krb5/rd_safe.c @@ -0,0 +1,214 @@ +/* + * Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "krb5_locl.h" + +static krb5_error_code +verify_checksum(krb5_context context, + krb5_auth_context auth_context, + KRB_SAFE *safe) +{ + krb5_error_code ret; + u_char *buf; + size_t buf_size; + size_t len = 0; + Checksum c; + krb5_crypto crypto; + krb5_keyblock *key; + + c = safe->cksum; + safe->cksum.cksumtype = 0; + safe->cksum.checksum.data = NULL; + safe->cksum.checksum.length = 0; + + ASN1_MALLOC_ENCODE(KRB_SAFE, buf, buf_size, safe, &len, ret); + if(ret) + return ret; + if(buf_size != len) + krb5_abortx(context, "internal error in ASN.1 encoder"); + + if (auth_context->remote_subkey) + key = auth_context->remote_subkey; + else if (auth_context->local_subkey) + key = auth_context->local_subkey; + else + key = auth_context->keyblock; + + ret = krb5_crypto_init(context, key, 0, &crypto); + if (ret) + goto out; + ret = krb5_verify_checksum (context, + crypto, + KRB5_KU_KRB_SAFE_CKSUM, + buf + buf_size - len, + len, + &c); + krb5_crypto_destroy(context, crypto); +out: + safe->cksum = c; + free (buf); + return ret; +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_safe(krb5_context context, + krb5_auth_context auth_context, + const krb5_data *inbuf, + krb5_data *outbuf, + krb5_replay_data *outdata) +{ + krb5_error_code ret; + KRB_SAFE safe; + size_t len; + + krb5_data_zero(outbuf); + + if ((auth_context->flags & + (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) + { + if (outdata == NULL) { + krb5_set_error_message(context, KRB5_RC_REQUIRED, + N_("rd_safe: need outdata " + "to return data", "")); + return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */ + } + /* if these fields are not present in the safe-part, silently + return zero */ + memset(outdata, 0, sizeof(*outdata)); + } + + ret = decode_KRB_SAFE (inbuf->data, inbuf->length, &safe, &len); + if (ret) + return ret; + if (safe.pvno != 5) { + ret = KRB5KRB_AP_ERR_BADVERSION; + krb5_clear_error_message (context); + goto failure; + } + if (safe.msg_type != krb_safe) { + ret = KRB5KRB_AP_ERR_MSG_TYPE; + krb5_clear_error_message (context); + goto failure; + } + if (!krb5_checksum_is_keyed(context, safe.cksum.cksumtype) + || !krb5_checksum_is_collision_proof(context, safe.cksum.cksumtype)) { + ret = KRB5KRB_AP_ERR_INAPP_CKSUM; + krb5_clear_error_message (context); + goto failure; + } + + /* check sender address */ + + if (safe.safe_body.s_address + && auth_context->remote_address + && !krb5_address_compare (context, + auth_context->remote_address, + safe.safe_body.s_address)) { + ret = KRB5KRB_AP_ERR_BADADDR; + krb5_clear_error_message (context); + goto failure; + } + + /* check receiver address */ + + if (safe.safe_body.r_address + && auth_context->local_address + && !krb5_address_compare (context, + auth_context->local_address, + safe.safe_body.r_address)) { + ret = KRB5KRB_AP_ERR_BADADDR; + krb5_clear_error_message (context); + goto failure; + } + + /* check timestamp */ + if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) { + krb5_timestamp sec; + + krb5_timeofday (context, &sec); + + if (safe.safe_body.timestamp == NULL || + safe.safe_body.usec == NULL || + krb5_time_abs(*safe.safe_body.timestamp, sec) > context->max_skew) { + ret = KRB5KRB_AP_ERR_SKEW; + krb5_clear_error_message (context); + goto failure; + } + } + /* XXX - check replay cache */ + + /* check sequence number. since MIT krb5 cannot generate a sequence + number of zero but instead generates no sequence number, we accept that + */ + + if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) { + if ((safe.safe_body.seq_number == NULL + && auth_context->remote_seqnumber != 0) + || (safe.safe_body.seq_number != NULL + && *safe.safe_body.seq_number != + auth_context->remote_seqnumber)) { + ret = KRB5KRB_AP_ERR_BADORDER; + krb5_clear_error_message (context); + goto failure; + } + auth_context->remote_seqnumber++; + } + + ret = verify_checksum (context, auth_context, &safe); + if (ret) + goto failure; + + outbuf->length = safe.safe_body.user_data.length; + outbuf->data = malloc(outbuf->length); + if (outbuf->data == NULL && outbuf->length != 0) { + ret = krb5_enomem(context); + krb5_data_zero(outbuf); + goto failure; + } + memcpy (outbuf->data, safe.safe_body.user_data.data, outbuf->length); + + if ((auth_context->flags & + (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) { + + if(safe.safe_body.timestamp) + outdata->timestamp = *safe.safe_body.timestamp; + if(safe.safe_body.usec) + outdata->usec = *safe.safe_body.usec; + if(safe.safe_body.seq_number) + outdata->seq = *safe.safe_body.seq_number; + } + + failure: + free_KRB_SAFE (&safe); + return ret; +} |