summaryrefslogtreecommitdiffstats
path: root/contrib/bsnmp
diff options
context:
space:
mode:
authorsyrinx <syrinx@FreeBSD.org>2013-10-17 11:49:46 +0000
committersyrinx <syrinx@FreeBSD.org>2013-10-17 11:49:46 +0000
commitf7282ff245e4c8ffa3c6689fc2714d94bdf5863e (patch)
tree78b203f49281a1f8b30ef14d14de7ea0fafb6aa6 /contrib/bsnmp
parentb7fd4846e58549b232ed7e909aafea11ca0ec2a6 (diff)
downloadFreeBSD-src-f7282ff245e4c8ffa3c6689fc2714d94bdf5863e.zip
FreeBSD-src-f7282ff245e4c8ffa3c6689fc2714d94bdf5863e.tar.gz
Fix SNMP Error response PDUs and properly encode them when using v3 auth/encryption.
Reported by: harti@
Diffstat (limited to 'contrib/bsnmp')
-rw-r--r--contrib/bsnmp/lib/snmp.c8
-rw-r--r--contrib/bsnmp/lib/snmp.h2
-rw-r--r--contrib/bsnmp/lib/snmpagent.c47
3 files changed, 49 insertions, 8 deletions
diff --git a/contrib/bsnmp/lib/snmp.c b/contrib/bsnmp/lib/snmp.c
index 744510c..6b9e3e8 100644
--- a/contrib/bsnmp/lib/snmp.c
+++ b/contrib/bsnmp/lib/snmp.c
@@ -288,11 +288,13 @@ parse_secparams(struct asn_buf *b, struct snmp_pdu *pdu)
memset(buf, 0, 256);
tb.asn_ptr = buf;
tb.asn_len = 256;
+ u_int len;
- if (asn_get_octetstring(b, buf, &tb.asn_len) != ASN_ERR_OK) {
+ if (asn_get_octetstring(b, buf, &len) != ASN_ERR_OK) {
snmp_error("cannot parse usm header");
return (ASN_ERR_FAILED);
}
+ tb.asn_len = len;
if (asn_get_sequence(&tb, &octs_len) != ASN_ERR_OK) {
snmp_error("cannot decode usm header");
@@ -864,7 +866,7 @@ snmp_fix_encoding(struct asn_buf *b, struct snmp_pdu *pdu)
return (SNMP_CODE_FAILED);
pdu->scoped_len = b->asn_ptr - pdu->scoped_ptr;
- if ((code = snmp_pdu_fix_padd(b, pdu))!= ASN_ERR_OK)
+ if (snmp_pdu_fix_padd(b, pdu) != ASN_ERR_OK)
return (SNMP_CODE_FAILED);
if (pdu->security_model != SNMP_SECMODEL_USM)
@@ -997,7 +999,7 @@ snmp_pdu_encode(struct snmp_pdu *pdu, struct asn_buf *resp_b)
if ((err = snmp_pdu_encode_header(resp_b, pdu)) != SNMP_CODE_OK)
return (err);
for (idx = 0; idx < pdu->nbindings; idx++)
- if ((err = snmp_binding_encode(resp_b, &pdu->bindings[idx]))
+ if (snmp_binding_encode(resp_b, &pdu->bindings[idx])
!= ASN_ERR_OK)
return (SNMP_CODE_FAILED);
diff --git a/contrib/bsnmp/lib/snmp.h b/contrib/bsnmp/lib/snmp.h
index 631d2f2..4657336 100644
--- a/contrib/bsnmp/lib/snmp.h
+++ b/contrib/bsnmp/lib/snmp.h
@@ -182,7 +182,7 @@ struct snmp_pdu {
/* fixes for encoding */
size_t outer_len;
- size_t scoped_len;
+ asn_len_t scoped_len;
u_char *outer_ptr;
u_char *digest_ptr;
u_char *encrypted_ptr;
diff --git a/contrib/bsnmp/lib/snmpagent.c b/contrib/bsnmp/lib/snmpagent.c
index 888d622..ee92420 100644
--- a/contrib/bsnmp/lib/snmpagent.c
+++ b/contrib/bsnmp/lib/snmpagent.c
@@ -166,7 +166,7 @@ find_subnode(const struct snmp_value *value)
}
static void
-snmp_pdu_create_response(struct snmp_pdu *pdu, struct snmp_pdu *resp)
+snmp_pdu_create_response(const struct snmp_pdu *pdu, struct snmp_pdu *resp)
{
memset(resp, 0, sizeof(*resp));
strcpy(resp->community, pdu->community);
@@ -952,18 +952,57 @@ enum snmp_ret
snmp_make_errresp(const struct snmp_pdu *pdu, struct asn_buf *pdu_b,
struct asn_buf *resp_b)
{
+ u_char type;
asn_len_t len;
struct snmp_pdu resp;
enum asn_err err;
enum snmp_code code;
- memset(&resp, 0, sizeof(resp));
+ snmp_pdu_create_response(pdu, &resp);
+
if ((code = snmp_pdu_decode_header(pdu_b, &resp)) != SNMP_CODE_OK)
return (SNMP_RET_IGN);
- if (pdu_b->asn_len < len)
+ if (pdu->version == SNMP_V3) {
+ if (resp.user.priv_proto != SNMP_PRIV_NOPRIV &&
+ (asn_get_header(pdu_b, &type, &resp.scoped_len) != ASN_ERR_OK
+ || type != ASN_TYPE_OCTETSTRING)) {
+ snmp_error("cannot decode encrypted pdu");
+ return (SNMP_RET_IGN);
+ }
+
+ if (asn_get_sequence(pdu_b, &len) != ASN_ERR_OK) {
+ snmp_error("cannot decode scoped pdu header");
+ return (SNMP_RET_IGN);
+ }
+
+ len = SNMP_ENGINE_ID_SIZ;
+ if (asn_get_octetstring(pdu_b, (u_char *)resp.context_engine,
+ &len) != ASN_ERR_OK) {
+ snmp_error("cannot decode msg context engine");
+ return (SNMP_RET_IGN);
+ }
+ resp.context_engine_len = len;
+ len = SNMP_CONTEXT_NAME_SIZ;
+ if (asn_get_octetstring(pdu_b, (u_char *)resp.context_name,
+ &len) != ASN_ERR_OK) {
+ snmp_error("cannot decode msg context name");
+ return (SNMP_RET_IGN);
+ }
+ resp.context_name[len] = '\0';
+ }
+
+
+ if (asn_get_header(pdu_b, &type, &len) != ASN_ERR_OK) {
+ snmp_error("cannot get pdu header");
return (SNMP_RET_IGN);
- pdu_b->asn_len = len;
+ }
+
+ if ((type & ~ASN_TYPE_MASK) !=
+ (ASN_TYPE_CONSTRUCTED | ASN_CLASS_CONTEXT)) {
+ snmp_error("bad pdu header tag");
+ return (SNMP_RET_IGN);
+ }
err = snmp_parse_pdus_hdr(pdu_b, &resp, &len);
if (ASN_ERR_STOPPED(err))
OpenPOWER on IntegriCloud