[30122] in CVS-changelog-for-Kerberos-V5
krb5 commit: Refactor KDC krb5_pa_data utility functions
daemon@ATHENA.MIT.EDU (Greg Hudson)
Mon Mar 12 11:18:53 2018
Date: Mon, 12 Mar 2018 11:18:41 -0400
From: Greg Hudson <ghudson@mit.edu>
Message-Id: <201803121518.w2CFIfBI007568@drugstore.mit.edu>
To: cvs-krb5@mit.edu
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https://github.com/krb5/krb5/commit/4af478c18b02e1d2444a328bb79e6976ef3d312b
commit 4af478c18b02e1d2444a328bb79e6976ef3d312b
Author: Greg Hudson <ghudson@mit.edu>
Date: Thu Dec 21 11:28:52 2017 -0500
Refactor KDC krb5_pa_data utility functions
Move alloc_padata from fast_util.c to kdc_util.c and make it
non-static so it can be used by other files. Rename it to
alloc_pa_data for consistency with add_pa_data_element. Make it
correctly handle zero length using a null contents pointer.
Make add_pa_data_element claim both the container and contents memory
from the caller, now that callers can use alloc_pa_data to simplify
allocation and copying. Remove the copy parameter and the unused
context parameter, and put the list parameter first. Adjust all
callers accordingly, making small simplifications to memory handling
where applicable.
src/kdc/fast_util.c | 28 +-------
src/kdc/kdc_preauth.c | 14 ++--
src/kdc/kdc_util.c | 183 +++++++++++++++++++++++++------------------------
src/kdc/kdc_util.h | 8 +-
4 files changed, 107 insertions(+), 126 deletions(-)
diff --git a/src/kdc/fast_util.c b/src/kdc/fast_util.c
index e05107e..6a3fc11 100644
--- a/src/kdc/fast_util.c
+++ b/src/kdc/fast_util.c
@@ -451,36 +451,12 @@ kdc_fast_hide_client(struct kdc_request_state *state)
return (state->fast_options & KRB5_FAST_OPTION_HIDE_CLIENT_NAMES) != 0;
}
-/* Allocate a pa-data entry with an uninitialized buffer of size len. */
-static krb5_error_code
-alloc_padata(krb5_preauthtype pa_type, size_t len, krb5_pa_data **out)
-{
- krb5_pa_data *pa;
- uint8_t *buf;
-
- *out = NULL;
- buf = malloc(len);
- if (buf == NULL)
- return ENOMEM;
- pa = malloc(sizeof(*pa));
- if (pa == NULL) {
- free(buf);
- return ENOMEM;
- }
- pa->magic = KV5M_PA_DATA;
- pa->pa_type = pa_type;
- pa->length = len;
- pa->contents = buf;
- *out = pa;
- return 0;
-}
-
/* Create a pa-data entry with the specified type and contents. */
static krb5_error_code
make_padata(krb5_preauthtype pa_type, const void *contents, size_t len,
krb5_pa_data **out)
{
- if (alloc_padata(pa_type, len, out) != 0)
+ if (alloc_pa_data(pa_type, len, out) != 0)
return ENOMEM;
memcpy((*out)->contents, contents, len);
return 0;
@@ -720,7 +696,7 @@ kdc_fast_make_cookie(krb5_context context, struct kdc_request_state *state,
goto cleanup;
/* Construct the cookie pa-data entry. */
- ret = alloc_padata(KRB5_PADATA_FX_COOKIE, 8 + enc.ciphertext.length, &pa);
+ ret = alloc_pa_data(KRB5_PADATA_FX_COOKIE, 8 + enc.ciphertext.length, &pa);
memcpy(pa->contents, "MIT1", 4);
store_32_be(kvno, pa->contents + 4);
memcpy(pa->contents + 8, enc.ciphertext.data, enc.ciphertext.length);
diff --git a/src/kdc/kdc_preauth.c b/src/kdc/kdc_preauth.c
index 739c5e7..edc30bd 100644
--- a/src/kdc/kdc_preauth.c
+++ b/src/kdc/kdc_preauth.c
@@ -1617,18 +1617,20 @@ return_referral_enc_padata( krb5_context context,
{
krb5_error_code code;
krb5_tl_data tl_data;
- krb5_pa_data pa_data;
+ krb5_pa_data *pa;
tl_data.tl_data_type = KRB5_TL_SVR_REFERRAL_DATA;
code = krb5_dbe_lookup_tl_data(context, server, &tl_data);
if (code || tl_data.tl_data_length == 0)
return 0;
- pa_data.magic = KV5M_PA_DATA;
- pa_data.pa_type = KRB5_PADATA_SVR_REFERRAL_INFO;
- pa_data.length = tl_data.tl_data_length;
- pa_data.contents = tl_data.tl_data_contents;
- return add_pa_data_element(context, &pa_data, &reply->enc_padata, TRUE);
+ code = alloc_pa_data(KRB5_PADATA_SVR_REFERRAL_INFO, tl_data.tl_data_length,
+ &pa);
+ if (code)
+ return code;
+ memcpy(pa->contents, tl_data.tl_data_contents, tl_data.tl_data_length);
+ /* add_pa_data_element() claims pa on success or failure. */
+ return add_pa_data_element(&reply->enc_padata, pa);
}
krb5_error_code
diff --git a/src/kdc/kdc_util.c b/src/kdc/kdc_util.c
index 754570c..1311121 100644
--- a/src/kdc/kdc_util.c
+++ b/src/kdc/kdc_util.c
@@ -1353,9 +1353,9 @@ kdc_make_s4u2self_rep(krb5_context context,
krb5_enc_kdc_rep_part *reply_encpart)
{
krb5_error_code code;
- krb5_data *data = NULL;
+ krb5_data *der_user_id = NULL, *der_s4u_x509_user = NULL;
krb5_pa_s4u_x509_user rep_s4u_user;
- krb5_pa_data padata;
+ krb5_pa_data *pa;
krb5_enctype enctype;
krb5_keyusage usage;
@@ -1366,7 +1366,7 @@ kdc_make_s4u2self_rep(krb5_context context,
rep_s4u_user.user_id.options =
req_s4u_user->user_id.options & KRB5_S4U_OPTS_USE_REPLY_KEY_USAGE;
- code = encode_krb5_s4u_userid(&rep_s4u_user.user_id, &data);
+ code = encode_krb5_s4u_userid(&rep_s4u_user.user_id, &der_user_id);
if (code != 0)
goto cleanup;
@@ -1377,29 +1377,25 @@ kdc_make_s4u2self_rep(krb5_context context,
code = krb5_c_make_checksum(context, req_s4u_user->cksum.checksum_type,
tgs_subkey != NULL ? tgs_subkey : tgs_session,
- usage, data,
- &rep_s4u_user.cksum);
+ usage, der_user_id, &rep_s4u_user.cksum);
if (code != 0)
goto cleanup;
- krb5_free_data(context, data);
- data = NULL;
-
- code = encode_krb5_pa_s4u_x509_user(&rep_s4u_user, &data);
+ code = encode_krb5_pa_s4u_x509_user(&rep_s4u_user, &der_s4u_x509_user);
if (code != 0)
goto cleanup;
- padata.magic = KV5M_PA_DATA;
- padata.pa_type = KRB5_PADATA_S4U_X509_USER;
- padata.length = data->length;
- padata.contents = (krb5_octet *)data->data;
-
- code = add_pa_data_element(context, &padata, &reply->padata, FALSE);
+ /* Add a padata element, stealing memory from der_s4u_x509_user. */
+ code = alloc_pa_data(KRB5_PADATA_S4U_X509_USER, 0, &pa);
+ if (code != 0)
+ goto cleanup;
+ pa->length = der_s4u_x509_user->length;
+ pa->contents = (uint8_t *)der_s4u_x509_user->data;
+ der_s4u_x509_user->data = NULL;
+ /* add_pa_data_element() claims pa on success or failure. */
+ code = add_pa_data_element(&reply->padata, pa);
if (code != 0)
goto cleanup;
-
- free(data);
- data = NULL;
if (tgs_subkey != NULL)
enctype = tgs_subkey->enctype;
@@ -1413,33 +1409,27 @@ kdc_make_s4u2self_rep(krb5_context context,
*/
if ((req_s4u_user->user_id.options & KRB5_S4U_OPTS_USE_REPLY_KEY_USAGE) &&
enctype_requires_etype_info_2(enctype) == FALSE) {
- padata.length = req_s4u_user->cksum.length +
- rep_s4u_user.cksum.length;
- padata.contents = malloc(padata.length);
- if (padata.contents == NULL) {
- code = ENOMEM;
+ code = alloc_pa_data(KRB5_PADATA_S4U_X509_USER,
+ req_s4u_user->cksum.length +
+ rep_s4u_user.cksum.length, &pa);
+ if (code != 0)
goto cleanup;
- }
+ memcpy(pa->contents,
+ req_s4u_user->cksum.contents, req_s4u_user->cksum.length);
+ memcpy(&pa->contents[req_s4u_user->cksum.length],
+ rep_s4u_user.cksum.contents, rep_s4u_user.cksum.length);
- memcpy(padata.contents,
- req_s4u_user->cksum.contents,
- req_s4u_user->cksum.length);
- memcpy(&padata.contents[req_s4u_user->cksum.length],
- rep_s4u_user.cksum.contents,
- rep_s4u_user.cksum.length);
-
- code = add_pa_data_element(context,&padata,
- &reply_encpart->enc_padata, FALSE);
- if (code != 0) {
- free(padata.contents);
+ /* add_pa_data_element() claims pa on success or failure. */
+ code = add_pa_data_element(&reply_encpart->enc_padata, pa);
+ if (code != 0)
goto cleanup;
- }
}
cleanup:
if (rep_s4u_user.cksum.contents != NULL)
krb5_free_checksum_contents(context, &rep_s4u_user.cksum);
- krb5_free_data(context, data);
+ krb5_free_data(context, der_user_id);
+ krb5_free_data(context, der_s4u_x509_user);
return code;
}
@@ -1707,46 +1697,50 @@ enctype_requires_etype_info_2(krb5_enctype enctype)
}
}
-/* XXX where are the generic helper routines for this? */
+/* Allocate a pa-data entry with an uninitialized buffer of size len. */
krb5_error_code
-add_pa_data_element(krb5_context context,
- krb5_pa_data *padata,
- krb5_pa_data ***inout_padata,
- krb5_boolean copy)
+alloc_pa_data(krb5_preauthtype pa_type, size_t len, krb5_pa_data **out)
{
- int i;
- krb5_pa_data **p;
+ krb5_pa_data *pa;
+ uint8_t *buf = NULL;
- if (*inout_padata != NULL) {
- for (i = 0; (*inout_padata)[i] != NULL; i++)
- ;
- } else
- i = 0;
-
- p = realloc(*inout_padata, (i + 2) * sizeof(krb5_pa_data *));
- if (p == NULL)
- return ENOMEM;
-
- *inout_padata = p;
-
- p[i] = (krb5_pa_data *)malloc(sizeof(krb5_pa_data));
- if (p[i] == NULL)
+ *out = NULL;
+ if (len > 0) {
+ buf = malloc(len);
+ if (buf == NULL)
+ return ENOMEM;
+ }
+ pa = malloc(sizeof(*pa));
+ if (pa == NULL) {
+ free(buf);
return ENOMEM;
- *(p[i]) = *padata;
+ }
+ pa->magic = KV5M_PA_DATA;
+ pa->pa_type = pa_type;
+ pa->length = len;
+ pa->contents = buf;
+ *out = pa;
+ return 0;
+}
- p[i + 1] = NULL;
+/* Add pa to list, claiming its memory. Free pa on failure. */
+krb5_error_code
+add_pa_data_element(krb5_pa_data ***list, krb5_pa_data *pa)
+{
+ size_t count;
+ krb5_pa_data **newlist;
- if (copy) {
- p[i]->contents = (krb5_octet *)malloc(padata->length);
- if (p[i]->contents == NULL) {
- free(p[i]);
- p[i] = NULL;
- return ENOMEM;
- }
+ for (count = 0; *list != NULL && (*list)[count] != NULL; count++);
- memcpy(p[i]->contents, padata->contents, padata->length);
+ newlist = realloc(*list, (count + 2) * sizeof(*newlist));
+ if (newlist == NULL) {
+ free(pa->contents);
+ free(pa);
+ return ENOMEM;
}
-
+ newlist[count] = pa;
+ newlist[count + 1] = NULL;
+ *list = newlist;
return 0;
}
@@ -1850,38 +1844,47 @@ kdc_handle_protected_negotiation(krb5_context context,
{
krb5_error_code retval = 0;
krb5_checksum checksum;
- krb5_data *out = NULL;
- krb5_pa_data pa, *pa_in;
+ krb5_data *der_cksum = NULL;
+ krb5_pa_data *pa, *pa_in;
+
+ memset(&checksum, 0, sizeof(checksum));
+
pa_in = krb5int_find_pa_data(context, request->padata,
KRB5_ENCPADATA_REQ_ENC_PA_REP);
if (pa_in == NULL)
return 0;
- pa.magic = KV5M_PA_DATA;
- pa.pa_type = KRB5_ENCPADATA_REQ_ENC_PA_REP;
- memset(&checksum, 0, sizeof(checksum));
- retval = krb5_c_make_checksum(context,0, reply_key,
- KRB5_KEYUSAGE_AS_REQ, req_pkt, &checksum);
+
+ /* Compute and encode a checksum over the AS-REQ. */
+ retval = krb5_c_make_checksum(context, 0, reply_key, KRB5_KEYUSAGE_AS_REQ,
+ req_pkt, &checksum);
if (retval != 0)
goto cleanup;
- retval = encode_krb5_checksum(&checksum, &out);
+ retval = encode_krb5_checksum(&checksum, &der_cksum);
if (retval != 0)
goto cleanup;
- pa.contents = (krb5_octet *) out->data;
- pa.length = out->length;
- retval = add_pa_data_element(context, &pa, out_enc_padata, FALSE);
+
+ /* Add a pa-data element to the list, stealing memory from der_cksum. */
+ retval = alloc_pa_data(KRB5_ENCPADATA_REQ_ENC_PA_REP, 0, &pa);
+ if (retval)
+ goto cleanup;
+ pa->length = der_cksum->length;
+ pa->contents = (uint8_t *)der_cksum->data;
+ der_cksum->data = NULL;
+ /* add_pa_data_element() claims pa on success or failure. */
+ retval = add_pa_data_element(out_enc_padata, pa);
if (retval)
goto cleanup;
- out->data = NULL;
- pa.magic = KV5M_PA_DATA;
- pa.pa_type = KRB5_PADATA_FX_FAST;
- pa.length = 0;
- pa.contents = NULL;
- retval = add_pa_data_element(context, &pa, out_enc_padata, FALSE);
+
+ /* Add a zero-length PA-FX-FAST element to the list. */
+ retval = alloc_pa_data(KRB5_PADATA_FX_FAST, 0, &pa);
+ if (retval)
+ goto cleanup;
+ /* add_pa_data_element() claims pa on success or failure. */
+ retval = add_pa_data_element(out_enc_padata, pa);
+
cleanup:
- if (checksum.contents)
- krb5_free_checksum_contents(context, &checksum);
- if (out != NULL)
- krb5_free_data(context, out);
+ krb5_free_checksum_contents(context, &checksum);
+ krb5_free_data(context, der_cksum);
return retval;
}
diff --git a/src/kdc/kdc_util.h b/src/kdc/kdc_util.h
index f99efcf..18649b8 100644
--- a/src/kdc/kdc_util.h
+++ b/src/kdc/kdc_util.h
@@ -203,10 +203,10 @@ void
free_padata_context(krb5_context context, void *padata_context);
krb5_error_code
-add_pa_data_element (krb5_context context,
- krb5_pa_data *padata,
- krb5_pa_data ***out_padata,
- krb5_boolean copy);
+alloc_pa_data(krb5_preauthtype pa_type, size_t len, krb5_pa_data **out);
+
+krb5_error_code
+add_pa_data_element(krb5_pa_data ***list, krb5_pa_data *pa);
/* kdc_preauth_ec.c */
krb5_error_code
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