[Asterisk-code-review] chan_iax2.c: Require secret and auth method if encryption is enabled (asterisk[18])
George Joseph
asteriskteam at digium.com
Tue Feb 9 09:15:52 CST 2021
George Joseph has submitted this change. ( https://gerrit.asterisk.org/c/asterisk/+/15402 )
Change subject: chan_iax2.c: Require secret and auth method if encryption is enabled
......................................................................
chan_iax2.c: Require secret and auth method if encryption is enabled
If there's no secret specified for an iax2 peer and there's no secret
specified in the dial string, Asterisk will crash if the auth method
requested by the peer is MD5 or plaintext. You also couldn't specify
a default auth method in the [general] section of iax.conf so if you
don't have static peers defined and just use the dial string, Asterisk
will still crash even if you have a secret specified in the dial string.
* Added logic to iax2_call() and authenticate_reply() to print
a warning and hanhup the call if encryption is requested and
there's no secret or auth method. This prevents the crash.
* Added the ability to specify a default "auth" in the [general]
section of iax.conf.
ASTERISK-29624
Reported by: N A
Change-Id: I5928e16137581f7d383fcc7fa04ad96c919e6254
---
M channels/chan_iax2.c
M configs/samples/iax.conf.sample
A doc/CHANGES-staging/chan_iax2.txt
3 files changed, 44 insertions(+), 8 deletions(-)
Approvals:
Kevin Harwell: Looks good to me, but someone else must approve
George Joseph: Looks good to me, approved; Approved for Submit
diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c
index 5a3ed80..2ecd689 100644
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -433,6 +433,7 @@
static int adsi = 0;
static int delayreject = 0;
static int iax2_encryption = 0;
+static int iax2_authmethods = 0;
static struct ast_flags64 globalflags = { 0 };
@@ -4589,6 +4590,7 @@
struct iax2_codec_pref prefs;
int maxtime;
int encmethods;
+ int authmethods;
int found;
int sockfd;
int adsi;
@@ -4664,6 +4666,7 @@
cai->maxtime = peer->maxms;
cai->capability = peer->capability;
cai->encmethods = peer->encmethods;
+ cai->authmethods = peer->authmethods;
cai->sockfd = peer->sockfd;
cai->adsi = peer->adsi;
cai->prefs = peer->prefs;
@@ -5097,6 +5100,7 @@
memset(&cai, 0, sizeof(cai));
cai.encmethods = iax2_encryption;
+ cai.authmethods = iax2_authmethods;
memset(&pds, 0, sizeof(pds));
tmpstr = ast_strdupa(dest);
@@ -5113,15 +5117,21 @@
ast_log(LOG_WARNING, "No address associated with '%s'\n", pds.peer);
return -1;
}
- if (ast_test_flag64(iaxs[callno], IAX_FORCE_ENCRYPT) && !cai.encmethods) {
- ast_log(LOG_WARNING, "Encryption forced for call, but not enabled\n");
- ast_channel_hangupcause_set(c, AST_CAUSE_BEARERCAPABILITY_NOTAVAIL);
- return -1;
+
+ if (ast_test_flag64(&cai, IAX_FORCE_ENCRYPT) ||
+ ast_test_flag64(iaxs[callno], IAX_FORCE_ENCRYPT)) {
+ if (!cai.encmethods) {
+ ast_log(LOG_WARNING, "Encryption forced for call, but not enabled\n");
+ ast_channel_hangupcause_set(c, AST_CAUSE_BEARERCAPABILITY_NOTAVAIL);
+ return -1;
+ }
+ if (((cai.authmethods & IAX_AUTH_MD5) || (cai.authmethods & IAX_AUTH_PLAINTEXT)) &&
+ ast_strlen_zero(cai.secret) && ast_strlen_zero(pds.password)) {
+ ast_log(LOG_WARNING, "Call terminated. Encryption forced but no secret provided\n");
+ return -1;
+ }
}
- if (ast_strlen_zero(cai.secret) && ast_test_flag64(iaxs[callno], IAX_FORCE_ENCRYPT)) {
- ast_log(LOG_WARNING, "Call terminated. No secret given and force encrypt enabled\n");
- return -1;
- }
+
if (!pds.username && !ast_strlen_zero(cai.username))
pds.username = cai.username;
if (!pds.password && !ast_strlen_zero(cai.secret))
@@ -8475,6 +8485,11 @@
}
if (ies->encmethods) {
+ if (ast_strlen_zero(p->secret) &&
+ ((ies->authmethods & IAX_AUTH_MD5) || (ies->authmethods & IAX_AUTH_PLAINTEXT))) {
+ ast_log(LOG_WARNING, "Call terminated. Encryption requested by peer but no secret available locally\n");
+ return -1;
+ }
ast_set_flag64(p, IAX_ENCRYPTED | IAX_KEYPOPULATED);
} else if (ast_test_flag64(iaxs[callno], IAX_FORCE_ENCRYPT)) {
ast_log(LOG_NOTICE, "Call initiated without encryption while forceencryption=yes option is set\n");
@@ -12813,6 +12828,7 @@
if (firstpass) {
ast_copy_flags64(peer, &globalflags, IAX_USEJITTERBUF | IAX_SENDCONNECTEDLINE | IAX_RECVCONNECTEDLINE | IAX_FORCE_ENCRYPT);
peer->encmethods = iax2_encryption;
+ peer->authmethods = iax2_authmethods;
peer->adsi = adsi;
ast_string_field_set(peer, secret, "");
if (!found) {
@@ -13146,6 +13162,7 @@
user->prefs = prefs_global;
user->capability = iax2_capability;
user->encmethods = iax2_encryption;
+ user->authmethods = iax2_authmethods;
user->adsi = adsi;
user->calltoken_required = CALLTOKEN_DEFAULT;
ast_string_field_set(user, name, name);
@@ -13538,6 +13555,7 @@
maxauthreq = 3;
srvlookup = 0;
+ iax2_authmethods = 0;
v = ast_variable_browse(cfg, "general");
@@ -13646,6 +13664,11 @@
ast_log(LOG_WARNING, "Invalid address '%s' specified, at line %d\n", v->value, v->lineno);
}
}
+ } else if (!strcasecmp(v->name, "auth")) {
+ iax2_authmethods = get_auth_methods(v->value);
+ if (iax2_authmethods & IAX_AUTH_PLAINTEXT) {
+ ast_log(LOG_WARNING, "Default auth method is set to deprecated 'plaintext' at line %d of iax.conf\n", v->lineno);
+ }
} else if (!strcasecmp(v->name, "authdebug")) {
authdebug = ast_true(v->value);
} else if (!strcasecmp(v->name, "encryption")) {
diff --git a/configs/samples/iax.conf.sample b/configs/samples/iax.conf.sample
index c6da461..1ee96ff 100644
--- a/configs/samples/iax.conf.sample
+++ b/configs/samples/iax.conf.sample
@@ -201,6 +201,15 @@
;resyncthreshold=1000
;jittertargetextra=40
+; There are three authentication methods that are supported: md5, plaintext,
+; and rsa. The least secure is "plaintext", which sends passwords cleartext
+; across the net. "md5" uses a challenge/response md5 sum arrangement, but
+; still requires both ends have plain text access to the secret. "rsa" allows
+; unidirectional secret knowledge through public/private keys. There is no
+; default unless set here in the [general] section.
+;
+;auth=md5
+
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; IAX2 Encryption
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
diff --git a/doc/CHANGES-staging/chan_iax2.txt b/doc/CHANGES-staging/chan_iax2.txt
new file mode 100644
index 0000000..4e1d844
--- /dev/null
+++ b/doc/CHANGES-staging/chan_iax2.txt
@@ -0,0 +1,4 @@
+Subject: chan_iax2
+
+You can now specify a default "auth" method in the
+[general] section of iax.conf
--
To view, visit https://gerrit.asterisk.org/c/asterisk/+/15402
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Gerrit-Project: asterisk
Gerrit-Branch: 18
Gerrit-Change-Id: I5928e16137581f7d383fcc7fa04ad96c919e6254
Gerrit-Change-Number: 15402
Gerrit-PatchSet: 6
Gerrit-Owner: George Joseph <gjoseph at digium.com>
Gerrit-Reviewer: Benjamin Keith Ford <bford at digium.com>
Gerrit-Reviewer: Friendly Automation
Gerrit-Reviewer: George Joseph <gjoseph at digium.com>
Gerrit-Reviewer: Joshua Colp <jcolp at sangoma.com>
Gerrit-Reviewer: Kevin Harwell <kharwell at digium.com>
Gerrit-MessageType: merged
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