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This is an automatically generated e-mail. To reply, visit:
<a href="https://reviewboard.asterisk.org/r/1173/">https://reviewboard.asterisk.org/r/1173/</a>
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<div>Review request for Asterisk Developers and Olle E Johansson.</div>
<div>By irroot.</div>
<p style="color: grey;"><i>Updated Aug. 27, 2011, 2:28 a.m.</i></p>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Changes</h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">New patch without the "encryption=try" optional / attempt SRTP bits it confuses the core issue of fixing the bug not setting the taglen correctly.
updated description to prevent confusion as seen by oej the option to set the taglen is "encryption_taglen=" the default is 80.
added oej onto the list after he so kindly reviewed it.</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description (updated)</h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">
Correctly handle the SRTP tag length either 32/80 this is not the key length / cipher strength.
currently only 80 is supported introducing problems.
the taglen in the incoming invite always is used outgoing invites will have the configured taglen [default 80] this fixes a serious interop issue and bug where the taglen was always set to 80 regardles of the incoming invite.
also there was no way to set the taglen for a new invite.
4.1 Crypto-suites
A crypto-suite value appears as the first parameter in a=crypto. The
CRYPTO-SUITE value MAY be different for SRTP and SRTCP as described
in Section 4.2. If a receiver does not support the particular
crypto-suite, then the receiver MUST NOT participate in the media
stream and SHOULD log an "unrecognized crypto-suite" condition
unless the receiver is participating in an Offer/Answer exchange
(Section 5). RTP/SAVP has four crypto-suites as described below.
4.1.1 AES_CM_128_HMAC_SHA1_80
This is the SRTP default AES Counter Mode cipher and HMAC-SHA1
message authentication having a 80-bit authentication tag. The
encryption and authentication key lengths are 128 bits. The master
salt value is 112 bits and the session salt value is 112 bits. The
PRF is the default SRTP pseudo-random function that uses AES Counter
Mode with a 128-bit key length.
4.1.2 AES_CM_128_HMAC_SHA1_32
The SRTP AES Counter Mode cipher is used with HMAC-SHA1 message
authentication having an 32-bit authentication tag. The encryption
and authentication key lengths are 128 bits. The master salt value
is 112 bits and the session salt value is 112 bits. These values
apply to SRTP and to SRTCP. The PRF is the default SRTP pseudo-
random function that uses AES Counter Mode with a 128-bit key
length.
4.1.3 F8_128_HMAC_SHA1_80
The SRTP f8 cipher is used with HMAC-SHA1 message authentication
having a 80-bit authentication tag. The encryption and
authentication key lengths are 128 bits. The master salt value is
112 bits and the session salt value is 112 bits. The PRF is the
default SRTP pseudo-random function that uses AES Counter Mode with
a 128-bit key length.
4.1.4 F8_128_HMAC_SHA1_32
The SRTP f8 cipher is used with HMAC-SHA1 message authentication
having a 32-bit authentication tag. The encryption and
authentication key lengths are 128 bits. The master salt value is
112 bits and the session salt value is 112 bits. The PRF is the
default SRTP pseudo-random function that uses AES Counter Mode with
a 128-bit key length. </pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing (updated)</h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">This has been rolled out to > 50 sites using 32 and 80 bit taglen.
the optional element has been removed from this patch to make the core bugfix see it to v10</pre>
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<div style="margin-top: 1.5em;">
<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="https://issues.asterisk.org/jira/browse/19335">19335</a>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> (updated)</h1>
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<li>/branches/10/channels/sip/include/sdp_crypto.h <span style="color: grey">(333337)</span></li>
<li>/branches/10/channels/sip/include/sip.h <span style="color: grey">(333337)</span></li>
<li>/branches/10/channels/sip/include/srtp.h <span style="color: grey">(333337)</span></li>
<li>/branches/10/channels/sip/sdp_crypto.c <span style="color: grey">(333337)</span></li>
<li>/branches/10/configs/sip.conf.sample <span style="color: grey">(333337)</span></li>
<li>/branches/10/CHANGES <span style="color: grey">(333337)</span></li>
<li>/branches/10/channels/chan_sip.c <span style="color: grey">(333337)</span></li>
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<p><a href="https://reviewboard.asterisk.org/r/1173/diff/" style="margin-left: 3em;">View Diff</a></p>
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