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|
#include "k5-int.h"
#include "cleanup.h"
#include "auth_con.h"
#include <stddef.h> /* NULL */
#include <stdlib.h> /* malloc */
#include <errno.h> /* ENOMEM */
/*-------------------- decrypt_credencdata --------------------*/
/*
* decrypt the enc_part of a krb5_cred
*/
static krb5_error_code
decrypt_credencdata(krb5_context context, krb5_cred *pcred, krb5_keyblock *pkeyblock, krb5_cred_enc_part *pcredenc)
{
krb5_cred_enc_part * ppart;
krb5_error_code retval;
krb5_data scratch;
scratch.length = pcred->enc_part.ciphertext.length;
if (!(scratch.data = (char *)malloc(scratch.length)))
return ENOMEM;
if (pkeyblock != NULL) {
if ((retval = krb5_c_decrypt(context, pkeyblock,
KRB5_KEYUSAGE_KRB_CRED_ENCPART, 0,
&pcred->enc_part, &scratch)))
goto cleanup;
} else {
memcpy(scratch.data, pcred->enc_part.ciphertext.data, scratch.length);
}
/* now decode the decrypted stuff */
if ((retval = decode_krb5_enc_cred_part(&scratch, &ppart)))
goto cleanup_encpart;
*pcredenc = *ppart;
retval = 0;
cleanup_encpart:
memset(ppart, 0, sizeof(*ppart));
krb5_xfree(ppart);
cleanup:
memset(scratch.data, 0, scratch.length);
krb5_xfree(scratch.data);
return retval;
}
/*----------------------- krb5_rd_cred_basic -----------------------*/
static krb5_error_code
krb5_rd_cred_basic(krb5_context context, krb5_data *pcreddata, krb5_keyblock *pkeyblock, krb5_replay_data *replaydata, krb5_creds ***pppcreds)
{
krb5_error_code retval;
krb5_cred * pcred;
krb5_int32 ncreds;
krb5_int32 i = 0;
krb5_cred_enc_part encpart;
/* decode cred message */
if ((retval = decode_krb5_cred(pcreddata, &pcred)))
return retval;
memset(&encpart, 0, sizeof(encpart));
if ((retval = decrypt_credencdata(context, pcred, pkeyblock, &encpart)))
goto cleanup_cred;
replaydata->timestamp = encpart.timestamp;
replaydata->usec = encpart.usec;
replaydata->seq = encpart.nonce;
/*
* Allocate the list of creds. The memory is allocated so that
* krb5_free_tgt_creds can be used to free the list.
*/
for (ncreds = 0; pcred->tickets[ncreds]; ncreds++);
if ((*pppcreds =
(krb5_creds **)malloc((size_t)(sizeof(krb5_creds *) *
(ncreds + 1)))) == NULL) {
retval = ENOMEM;
goto cleanup_cred;
}
(*pppcreds)[0] = NULL;
/*
* For each credential, create a strcture in the list of
* credentials and copy the information.
*/
while (i < ncreds) {
krb5_cred_info * pinfo;
krb5_creds * pcur;
krb5_data * pdata;
if ((pcur = (krb5_creds *)malloc(sizeof(krb5_creds))) == NULL) {
retval = ENOMEM;
goto cleanup;
}
(*pppcreds)[i] = pcur;
(*pppcreds)[i+1] = 0;
pinfo = encpart.ticket_info[i++];
memset(pcur, 0, sizeof(krb5_creds));
if ((retval = krb5_copy_principal(context, pinfo->client,
&pcur->client)))
goto cleanup;
if ((retval = krb5_copy_principal(context, pinfo->server,
&pcur->server)))
goto cleanup;
if ((retval = krb5_copy_keyblock_contents(context, pinfo->session,
&pcur->keyblock)))
goto cleanup;
if ((retval = krb5_copy_addresses(context, pinfo->caddrs,
&pcur->addresses)))
goto cleanup;
if ((retval = encode_krb5_ticket(pcred->tickets[i - 1], &pdata)))
goto cleanup;
pcur->ticket = *pdata;
krb5_xfree(pdata);
pcur->is_skey = FALSE;
pcur->magic = KV5M_CREDS;
pcur->times = pinfo->times;
pcur->ticket_flags = pinfo->flags;
pcur->authdata = NULL; /* not used */
memset(&pcur->second_ticket, 0, sizeof(pcur->second_ticket));
}
/*
* NULL terminate the list
*/
(*pppcreds)[i] = NULL;
cleanup:
if (retval)
krb5_free_tgt_creds(context, *pppcreds);
cleanup_cred:
krb5_free_cred(context, pcred);
krb5_free_cred_enc_part(context, &encpart);
return retval;
}
/*----------------------- krb5_rd_cred -----------------------*/
#define in_clock_skew(date) (labs((date)-currenttime) < context->clockskew)
/*
* This functions takes as input an KRB_CRED message, validates it, and
* outputs the nonce and an array of the forwarded credentials.
*/
krb5_error_code KRB5_CALLCONV
krb5_rd_cred(krb5_context context, krb5_auth_context auth_context, krb5_data *pcreddata, krb5_creds ***pppcreds, krb5_replay_data *outdata)
{
krb5_error_code retval;
krb5_keyblock * keyblock;
krb5_replay_data replaydata;
/* Get keyblock */
if ((keyblock = auth_context->remote_subkey) == NULL)
if ((keyblock = auth_context->local_subkey) == NULL)
keyblock = auth_context->keyblock;
if (((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
(outdata == NULL))
/* Need a better error */
return KRB5_RC_REQUIRED;
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) &&
(auth_context->rcache == NULL))
return KRB5_RC_REQUIRED;
/* If decrypting with the first keyblock we try fails, perhaps the
* credentials are stored in the session key so try decrypting with
* that.
*/
if ((retval = krb5_rd_cred_basic(context, pcreddata, keyblock,
&replaydata, pppcreds))) {
if ((retval = krb5_rd_cred_basic(context, pcreddata,
auth_context->keyblock,
&replaydata, pppcreds))) {
return retval;
}
}
if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) {
krb5_donot_replay replay;
krb5_timestamp currenttime;
if ((retval = krb5_timeofday(context, ¤ttime)))
goto error;
if (!in_clock_skew(replaydata.timestamp)) {
retval = KRB5KRB_AP_ERR_SKEW;
goto error;
}
if ((retval = krb5_gen_replay_name(context, auth_context->remote_addr,
"_forw", &replay.client)))
goto error;
replay.server = ""; /* XXX */
replay.cusec = replaydata.usec;
replay.ctime = replaydata.timestamp;
if ((retval = krb5_rc_store(context, auth_context->rcache, &replay))) {
krb5_xfree(replay.client);
goto error;
}
krb5_xfree(replay.client);
}
if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
if (auth_context->remote_seq_number != replaydata.seq) {
retval = KRB5KRB_AP_ERR_BADORDER;
goto error;
}
auth_context->remote_seq_number++;
}
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) {
outdata->timestamp = replaydata.timestamp;
outdata->usec = replaydata.usec;
outdata->seq = replaydata.seq;
}
error:;
if (retval) {
krb5_free_tgt_creds(context, *pppcreds);
*pppcreds = NULL;
}
return retval;
}
|
