draft-ietf-uta-tls-attacks-01.txt   draft-ietf-uta-tls-attacks-02.txt 
uta Y. Sheffer uta Y. Sheffer
Internet-Draft Porticor Internet-Draft Porticor
Intended status: Informational R. Holz Intended status: Informational R. Holz
Expires: December 26, 2014 TUM Expires: February 13, 2015 TUM
P. Saint-Andre P. Saint-Andre
&yet &yet
June 24, 2014 August 12, 2014
Summarizing Current Attacks on TLS and DTLS Summarizing Current Attacks on TLS and DTLS
draft-ietf-uta-tls-attacks-01 draft-ietf-uta-tls-attacks-02
Abstract Abstract
Over the last few years there have been several serious attacks on Over the last few years there have been several serious attacks on
TLS, including attacks on its most commonly used ciphers and modes of TLS, including attacks on its most commonly used ciphers and modes of
operation. This document summarizes these attacks, with the goal of operation. This document summarizes these attacks, with the goal of
motivating generic and protocol-specific recommendations on the usage motivating generic and protocol-specific recommendations on the usage
of TLS and DTLS. of TLS and DTLS.
Status of This Memo Status of This Memo
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 26, 2014. This Internet-Draft will expire on February 13, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Attacks on TLS . . . . . . . . . . . . . . . . . . . . . . . 3 2. Attacks on TLS . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. SSL Stripping . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. SSL Stripping . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. BEAST . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. BEAST . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3. Lucky Thirteen . . . . . . . . . . . . . . . . . . . . . . 3 2.3. Lucky Thirteen . . . . . . . . . . . . . . . . . . . . . . 3
2.4. Attacks on RC4 . . . . . . . . . . . . . . . . . . . . . . 3 2.4. Attacks on RC4 . . . . . . . . . . . . . . . . . . . . . . 3
2.5. Compression Attacks: CRIME and BREACH . . . . . . . . . . . 4 2.5. Compression Attacks: CRIME and BREACH . . . . . . . . . . . 4
2.6. Certificate Attacks . . . . . . . . . . . . . . . . . . . . 4 2.6. Certificate Attacks . . . . . . . . . . . . . . . . . . . . 4
2.7. Diffe-Hellman Parameters . . . . . . . . . . . . . . . . . 4 2.7. Diffie-Hellman Parameters . . . . . . . . . . . . . . . . . 4
2.8. Denial of Service . . . . . . . . . . . . . . . . . . . . . 4 2.8. Renegotiation . . . . . . . . . . . . . . . . . . . . . . . 5
3. Security Considerations . . . . . . . . . . . . . . . . . . . 5 2.9. Triple Hanshake . . . . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 2.10. Denial of Service . . . . . . . . . . . . . . . . . . . . . 5
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 2.11. Implementation Issues . . . . . . . . . . . . . . . . . . . 5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Applicability to DTLS . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . . 5 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
Appendix A. Appendix: Change Log . . . . . . . . . . . . . . . . 7 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6
A.1. draft-ietf-uta-tls-bcp-01 . . . . . . . . . . . . . . . . . 7 7. Informative References . . . . . . . . . . . . . . . . . . . 6
A.2. draft-ietf-uta-tls-bcp-00 . . . . . . . . . . . . . . . . . 7 Appendix A. Appendix: Change Log . . . . . . . . . . . . . . . . 9
A.3. draft-sheffer-uta-tls-bcp-00 . . . . . . . . . . . . . . . 7 A.1. draft-ietf-uta-tls-attacks-02 . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 A.2. draft-ietf-uta-tls-attacks-01 . . . . . . . . . . . . . . . 9
A.3. draft-ietf-uta-tls-attacks-00 . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction 1. Introduction
Over the last few years there have been several major attacks on TLS Over the last few years there have been several major attacks on TLS
[RFC5246], including attacks on its most commonly used ciphers and [RFC5246], including attacks on its most commonly used ciphers and
modes of operation. Details are given in Section 2, but suffice it modes of operation. Details are given in Section 2, but suffice it
to say that both AES-CBC and RC4, which together make up for most to say that both AES-CBC and RC4, which together make up for most
current usage, have been seriously attacked in the context of TLS. current usage, have been seriously attacked in the context of TLS.
This situation motivated the creation of the UTA working group, which This situation motivated the creation of the UTA working group, which
is tasked with the creation of generic and protocol-specific is tasked with the creation of generic and protocol-specific
recommendation for the use of TLS and DTLS. recommendations for the use of TLS and DTLS.
"Attacks always get better; they never get worse" (ironically, this "Attacks always get better; they never get worse" (ironically, this
saying is attributed to the NSA). This list of attacks describes our saying is attributed to the NSA). This list of attacks describes our
knowledge as of this writing. It seems likely that new attacks will knowledge as of this writing. It seems likely that new attacks will
be invented in the future. be invented in the future.
For a more detailed discussion of the attacks listed here, the For a more detailed discussion of the attacks listed here, the
interested reader is referred to [Attacks-iSec]. interested reader is referred to [Attacks-iSec].
2. Attacks on TLS 2. Attacks on TLS
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recommendations. This is not intended to be an extensive survey of recommendations. This is not intended to be an extensive survey of
TLS's security. TLS's security.
While there are widely deployed mitigations for some of the attacks While there are widely deployed mitigations for some of the attacks
listed below, we believe that their root causes necessitate a more listed below, we believe that their root causes necessitate a more
systemic solution. systemic solution.
2.1. SSL Stripping 2.1. SSL Stripping
Various attacks attempt to remove the use of SSL/TLS altogether, by Various attacks attempt to remove the use of SSL/TLS altogether, by
modifying HTTP traffic and HTML pages as they pass on the wire. modifying unencrypted protocols that request the use of TLS,
These attacks are known collectively as SSL Stripping, and were first specifically modifying HTTP traffic and HTML pages as they pass on
introduced by Moxie Marlinspike [SSL-Stripping]. In the context of the wire. These attacks are known collectively as SSL Stripping, and
Web traffic, these attacks are only effective if the client accesses were first introduced by Moxie Marlinspike [SSL-Stripping]. In the
a Web server using a mixture of HTTP and HTTPS. context of Web traffic, these attacks are only effective if the
client accesses a Web server using a mixture of HTTP and HTTPS.
2.2. BEAST 2.2. BEAST
The BEAST attack [BEAST] uses issues with the TLS 1.0 implementation The BEAST attack [BEAST] uses issues with the TLS 1.0 implementation
of CBC (that is, the predictable initialization vector) to decrypt of CBC (that is, the predictable initialization vector) to decrypt
parts of a packet, and specifically to decrypt HTTP cookies when HTTP parts of a packet, and specifically to decrypt HTTP cookies when HTTP
is run over TLS. is run over TLS.
2.3. Lucky Thirteen 2.3. Lucky Thirteen
A consequence of the MAC-then-encrypt design in all current versions A consequence of the MAC-then-encrypt design in all current versions
of TLS is the existence of padding oracle attacks [Padding-Oracle]. of TLS is the existence of padding oracle attacks [Padding-Oracle].
A recent incarnation of these attacks is the Lucky Thirteen attack A recent incarnation of these attacks is the Lucky Thirteen attack
[CBC-Attack], a timing side-channel attack that allows the attacker [CBC-Attack], a timing side-channel attack that allows the attacker
to decrypt arbitrary ciphertext. to decrypt arbitrary ciphertext.
The Lucky Thirteen attack can be mitigated by using authenticated
encryption like AES-GCM [RFC5288] and encrypt-then-mac
[I-D.ietf-tls-encrypt-then-mac] instead of the TLS default of MAC-
then-encrypt.
2.4. Attacks on RC4 2.4. Attacks on RC4
The RC4 algorithm [RC4] has been used with TLS (and previously, SSL) The RC4 algorithm [RC4] has been used with TLS (and previously, SSL)
for many years. RC4 has long been known to have a variety of for many years. RC4 has long been known to have a variety of
cryptographic weaknesses, e.g. [RC4-Attack-Pau], [RC4-Attack-Man], cryptographic weaknesses, e.g. [RC4-Attack-Pau], [RC4-Attack-Man],
[RC4-Attack-FMS]. Recent cryptanalysis results [RC4-Attack-AlF] [RC4-Attack-FMS]. Recent cryptanalysis results [RC4-Attack-AlF]
exploit biases in the RC4 keystream to recover repeatedly encrypted exploit biases in the RC4 keystream to recover repeatedly encrypted
plaintexts. plaintexts.
These recent results are on the verge of becoming practically These recent results are on the verge of becoming practically
exploitable; currently they require 2^26 sessions or 13x2^30 exploitable; currently they require 2^26 sessions or 13x2^30
encryptions. As a result, RC4 can no longer be seen as providing a encryptions. As a result, RC4 can no longer be seen as providing a
sufficient level of security for TLS sessions. sufficient level of security for TLS sessions. For further details,
the reader is refered to [I-D.ietf-tls-prohibiting-rc4].
2.5. Compression Attacks: CRIME and BREACH 2.5. Compression Attacks: CRIME and BREACH
The CRIME attack [CRIME] allows an active attacker to decrypt The CRIME attack [CRIME] allows an active attacker to decrypt
ciphertext (specifically, cookies) when TLS is used with protocol- ciphertext (specifically, cookies) when TLS is used with TLS level
level compression. compression.
The TIME attack [TIME] and the later BREACH attack [BREACH] both make The TIME attack [TIME] and the later BREACH attack [BREACH] both make
similar use of HTTP-level compression to decrypt secret data passed similar use of HTTP-level compression to decrypt secret data passed
in the HTTP response. We note that compression of the HTTP message in the HTTP response. We note that compression of the HTTP message
body is much more prevalent than compression at the TLS level. body is much more prevalent than compression at the TLS level.
The former attack can be mitigated by disabling TLS compression, as The former attack can be mitigated by disabling TLS compression. We
recommended below. We are not aware of mitigations at the protocol are not aware of mitigations at the TLS protocol level to the latter
level to the latter attack, and so application-level mitigations are attack, and so application-level mitigations are needed (see
needed (see [BREACH]). For example, implementations of HTTP that use [BREACH]). For example, implementations of HTTP that use CSRF tokens
CSRF tokens will need to randomize them even when the recommendations will need to randomize them even when the recommendations of
of [I-D.ietf-uta-tls-bcp] are adopted. [I-D.ietf-uta-tls-bcp] are adopted.
2.6. Certificate Attacks 2.6. Certificate Attacks
There have been several practical attacks on TLS when used with RSA There have been several practical attacks on TLS when used with RSA
certificates (the most common use case). These include certificates (the most common use case). These include
[Bleichenbacher98] and [Klima03]. While the Bleichenbacher attack [Bleichenbacher98] and [Klima03]. While the Bleichenbacher attack
has been mitigated in TLS 1.0, the Klima attack that relies on a has been mitigated in TLS 1.0, the Klima attack that relies on a
version-check oracle is only mitigated by TLS 1.1. version-check oracle is only mitigated by TLS 1.1.
The use of RSA certificates often involves exploitable timing issues The use of RSA certificates often involves exploitable timing issues
[Brumley03], unless the implementation takes care to explicitly [Brumley03], unless the implementation takes care to explicitly
eliminate them. eliminate them.
2.7. Diffe-Hellman Parameters 2.7. Diffie-Hellman Parameters
TLS allows to define ephemeral Diffie-Hellman and Elliptic Curve TLS allows to define ephemeral Diffie-Hellman and Elliptic Curve
Diffie-Hellman parameters in its respective key exchange modes. This Diffie-Hellman parameters in its respective key exchange modes. This
results in an outstanding attack, detailed in [Cross-Protocol]. In results in an outstanding attack, detailed in [Cross-Protocol]. In
addition, clients that do not properly verify the received parameters addition, clients that do not properly verify the received parameters
are exposed to MITM attacks. Unfortunately the TLS protocol does not are exposed to man in the middle (MITM) attacks. Unfortunately the
require this verification, see [RFC6989] for the IPsec analogy. TLS protocol does not require this verification, see [RFC6989] for
the IPsec analogy.
2.8. Denial of Service 2.8. Renegotiation
A major attack on the TLS renegotiation mechanism applies to all
current versions of the protocol. The attack and the TLS extension
that resolves it are described in [RFC5746].
2.9. Triple Hanshake
The triple handshake attack [[TRIPLE-HS, add the reference when
published]] enables the attacker to cause two TLS connections to
share keying material. This leads to a multitude of attacks, e.g.
Man-in-the-Middle, breaking safe renegotiation and breaking channel
binding via TLS Exporter [RFC5705] or "tls-unique" [RFC5929].
2.10. Denial of Service
Server CPU power has progressed over the years so that TLS can now be Server CPU power has progressed over the years so that TLS can now be
turned on by default. However the risk of malicious clients and turned on by default. However the risk of malicious clients and
coordinated groups of clients ("botnets") mounting denial of service coordinated groups of clients ("botnets") mounting denial of service
attacks is still very real. TLS adds another vector for attacks is still very real. TLS adds another vector for
computational attacks, since a client can easily (with little computational attacks, since a client can easily (with little
computational effort) force the server to expend relatively large computational effort) force the server to expend relatively large
computational work. It is known that such attacks have in fact been computational work. It is known that such attacks have in fact been
mounted. mounted.
3. Security Considerations 2.11. Implementation Issues
Even when the protocol is fully specified, the are very common issues
that often plague implementations. In particular, the integration of
higher-level protocols, TLS and its PKI-based authentication is the
source of misunderstandings and implementation "shortcuts". An
extensive survey of these issues can be found in [Georgiev2012].
o Implementations may omit validation of the server certificate
altogether. For example, this is true of the default
implementation of HTTP client libraries in Python 2.
o Implementations may not validate the server identity. This
validation typically amounts to matching the protocol-level server
name with the certificate's Subject Alternative Name field.
o Implementations may be validating the certificate chain
incorrectly or not at all, or using an incorrect or outdated trust
anchor list.
3. Applicability to DTLS
DTLS [RFC4347] [RFC6347] is an adaptation of TLS for UDP datagrams.
With respect to the attacks described in the current document, DTLS
1.0 is equivalent to TLS 1.1. The only exception is RC4 which is
disallowed in DTLS. DTLS 1.2 is equivalent to TLS 1.2.
4. Security Considerations
This document describes protocol attacks in an informational manner, This document describes protocol attacks in an informational manner,
and in itself does not have any security implications. Its companion and in itself does not have any security implications. Its companion
documents certainly do. documents certainly do.
4. IANA Considerations 5. IANA Considerations
This document requires no IANA actions. This document requires no IANA actions. [Note to RFC Editor: please
remove this whole section before publication.]
5. Acknowledgements 6. Acknowledgments
We would like to thank Stephen Farrell, Simon Josefsson, Yoav Nir, We would like to thank Stephen Farrell, Simon Josefsson, John
Kenny Paterson, Patrick Pelletier, Tom Ritter and Rich Salz for their Mattsson, Yoav Nir, Kenny Paterson, Patrick Pelletier, Tom Ritter and
review of this document. We thank Andrei Popov for contributing text Rich Salz for their review of this document. We thank Andrei Popov
on RC4. for contributing text on RC4, Kohei Kasamatsu for text on Lucky13,
Ilari Liusvaara for text on attacks and on DTLS.
The document was prepared using the lyx2rfc tool, created by Nico The document was prepared using the lyx2rfc tool, created by Nico
Williams. Williams.
6. References 7. Informative References
6.1. Normative References [RFC4347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security", RFC 4347, April 2006.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008. (TLS) Protocol Version 1.2", RFC 5246, August 2008.
6.2. Informative References [RFC5288] Salowey, J., Choudhury, A., and D. McGrew, "AES Galois
Counter Mode (GCM) Cipher Suites for TLS", RFC 5288,
August 2008.
[I-D.ietf-uta-tls-bcp] [RFC5705] Rescorla, E., "Keying Material Exporters for Transport
Sheffer, Y., Holz, R., and P. Saint-Andre, Layer Security (TLS)", RFC 5705, March 2010.
"Recommendations for Secure Use of TLS and DTLS", draft-
ietf-uta-tls-bcp-00 (work in progress), March 2014. [RFC5746] Rescorla, E., Ray, M., Dispensa, S., and N. Oskov,
"Transport Layer Security (TLS) Renegotiation Indication
Extension", RFC 5746, February 2010.
[RFC5929] Altman, J., Williams, N., and L. Zhu, "Channel Bindings
for TLS", RFC 5929, July 2010.
[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security Version 1.2", RFC 6347, January 2012.
[RFC6989] Sheffer, Y. and S. Fluhrer, "Additional Diffie-Hellman [RFC6989] Sheffer, Y. and S. Fluhrer, "Additional Diffie-Hellman
Tests for the Internet Key Exchange Protocol Version 2 Tests for the Internet Key Exchange Protocol Version 2
(IKEv2)", RFC 6989, July 2013. (IKEv2)", RFC 6989, July 2013.
[I-D.ietf-uta-tls-bcp]
Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of TLS and DTLS", draft-
ietf-uta-tls-bcp-01 (work in progress), June 2014.
[I-D.ietf-tls-prohibiting-rc4]
Popov, A., "Prohibiting RC4 Cipher Suites", draft-ietf-
tls-prohibiting-rc4-00 (work in progress), July 2014.
[I-D.ietf-tls-encrypt-then-mac]
Gutmann, P., "Encrypt-then-MAC for TLS and DTLS", draft-
ietf-tls-encrypt-then-mac-03 (work in progress), July
2014.
[CBC-Attack] [CBC-Attack]
AlFardan, N. and K. Paterson, "Lucky Thirteen: Breaking AlFardan, N. and K. Paterson, "Lucky Thirteen: Breaking
the TLS and DTLS Record Protocols", IEEE Symposium on the TLS and DTLS Record Protocols", IEEE Symposium on
Security and Privacy , 2013. Security and Privacy , 2013.
[BEAST] Rizzo, J. and T. Duong, "Browser Exploit Against SSL/TLS", [BEAST] Rizzo, J. and T. Duong, "Browser Exploit Against SSL/TLS",
2011, <http://packetstormsecurity.com/files/105499/ 2011, <http://packetstormsecurity.com/files/105499/
Browser-Exploit-Against-SSL-TLS.html>. Browser-Exploit-Against-SSL-TLS.html>.
[CRIME] Rizzo, J. and T. Duong, "The CRIME Attack", EKOparty [CRIME] Rizzo, J. and T. Duong, "The CRIME Attack", EKOparty
skipping to change at page 6, line 34 skipping to change at page 8, line 16
Fluhrer, S., Mantin, I., and A. Shamir, "Weaknesses in the Fluhrer, S., Mantin, I., and A. Shamir, "Weaknesses in the
Key Scheduling Algorithm of RC4", Selected Areas in Key Scheduling Algorithm of RC4", Selected Areas in
Cryptography , 2001. Cryptography , 2001.
[RC4-Attack-AlF] [RC4-Attack-AlF]
AlFardan, N., Bernstein, D., Paterson, K., Poettering, B., AlFardan, N., Bernstein, D., Paterson, K., Poettering, B.,
and J. Schuldt, "On the Security of RC4 in TLS", Usenix and J. Schuldt, "On the Security of RC4 in TLS", Usenix
Security Symposium 2013, 2013, <https://www.usenix.org/ Security Symposium 2013, 2013, <https://www.usenix.org/
conference/usenixsecurity13/security-rc4-tls>. conference/usenixsecurity13/security-rc4-tls>.
[Georgiev2012]
Georgiev, M., Iyengar, S., Jana, S., Anubhai, R., Boneh,
D., and V. Shmatikov, "The most dangerous code in the
world: validating SSL certificates in non-browser
software", 2012,
<http://doi.acm.org/10.1145/2382196.2382204>.
[Attacks-iSec] [Attacks-iSec]
Sarkar, P. and S. Fitzgerald, "Attacks on SSL, a Sarkar, P. and S. Fitzgerald, "Attacks on SSL, a
comprehensive study of BEAST, CRIME, TIME, BREACH, Lucky13 comprehensive study of BEAST, CRIME, TIME, BREACH, Lucky13
and RC4 biases", 8 2013, <https://www.isecpartners.com/ and RC4 biases", 8 2013, <https://www.isecpartners.com/
media/106031/ssl_attacks_survey.pdf>. media/106031/ssl_attacks_survey.pdf>.
[Padding-Oracle] [Padding-Oracle]
Vaudenay, S., "Security Flaws Induced by CBC Padding Vaudenay, S., "Security Flaws Induced by CBC Padding
Applications to SSL, IPSEC, WTLS...", EUROCRYPT 2002, Applications to SSL, IPSEC, WTLS...", EUROCRYPT 2002,
2002, <http://www.iacr.org/cryptodb/archive/2002/ 2002, <http://www.iacr.org/cryptodb/archive/2002/
skipping to change at page 7, line 35 skipping to change at page 9, line 21
sessions in SSL/TLS", 2003. sessions in SSL/TLS", 2003.
[Brumley03] [Brumley03]
Brumley, D. and D. Boneh, "Remote timing attacks are Brumley, D. and D. Boneh, "Remote timing attacks are
practical", 2003. practical", 2003.
Appendix A. Appendix: Change Log Appendix A. Appendix: Change Log
Note to RFC Editor: please remove this section before publication. Note to RFC Editor: please remove this section before publication.
A.1. draft-ietf-uta-tls-bcp-01 A.1. draft-ietf-uta-tls-attacks-02
o Added implementation issues ("most dangerous code"),
renegotiation, triple handshake.
o Added text re: mitigation of Lucky13.
o Added applicability to DTLS.
A.2. draft-ietf-uta-tls-attacks-01
o Added SSL Stripping, attacks related to certificates, Diffie o Added SSL Stripping, attacks related to certificates, Diffie
Hellman parameters and denial of service. Hellman parameters and denial of service.
o Expanded on RC4 attacks, thanks to Andrei Popov. o Expanded on RC4 attacks, thanks to Andrei Popov.
A.2. draft-ietf-uta-tls-bcp-00 A.3. draft-ietf-uta-tls-attacks-00
o Initial WG version, with only updated references.
A.3. draft-sheffer-uta-tls-bcp-00
o Initial version, extracted from draft-sheffer-tls-bcp-01. o Initial version, extracted from draft-sheffer-tls-bcp-01.
Authors' Addresses Authors' Addresses
Yaron Sheffer Yaron Sheffer
Porticor Porticor
29 HaHarash St. 29 HaHarash St.
Hod HaSharon 4501303 Hod HaSharon 4501303
Israel Israel
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