This reverts commit 51e3eafb68. There are
too many deployed AAA servers that include both id-kp-clientAuth and
id-kp-serverAuth EKUs for this change to be acceptable as a generic rule
for AAA authentication server validation. OpenSSL enforces the policy of
not connecting if only id-kp-clientAuth is included. If a valid EKU is
listed with it, the connection needs to be accepted.
Signed-off-by: Jouni Malinen <j@w1.fi>
This fixes issues in using a password that includes a UTF-8 character
with three-byte encoding with EAP methods that use NtPasswordHash
(anything using MSCHAPv2 or LEAP).
Signed-off-by: Jouni Malinen <j@w1.fi>
In function tls_verify_cb(), X509_STORE_CTX_get_current_cert() may
return NULL, and it will be dereferenced by X509_get_subject_name().
Signed-hostap: Eytan Lifshitz <eytan.lifshitz@intel.com>
These were somewhat more hidden to avoid direct use, but there are now
numerous places where these are needed and more justification to make
the extern int declarations available from wpa_debug.h. In addition,
this avoids some warnings from sparse.
Signed-hostap: Jouni Malinen <j@w1.fi>
If the extended key usage of the AAA server certificate indicates
that the certificate is for client use, reject the TLS handshake.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
OCSP response may not include all the needed CA certificates, so use the
ones received during TLS handshake.
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
It's not possible to get a raw private key from keystore anymore, so
this would fail every time anyway. Remove it so it doesn't confuse
anyone that looks at this code.
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
The new keystore ENGINE is usable to perform private key operations when
we can't get the actual private key data. This is the case when hardware
crypto is enabled: the private key never leaves the hardware.
Subsequently, we need to be able to talk to OpenSSL ENGINEs that aren't
PKCS#11 or OpenSC. This just changes a few #define variables to allow us
to talk to our keystore engine without having one of those enabled and
without using a PIN.
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
If SSL_CTX_new() fails in tls_init(), the per-SSL app-data allocation
could have been leaked when multiple TLS instances are allocated.
Signed-hostap: Jouni Malinen <j@w1.fi>
The new domain_suffix_match (and domain_suffix_match2 for Phase 2
EAP-TLS) can now be used to specify an additional constraint for the
server certificate domain name. If set, one of the dNSName values (or if
no dNSName is present, one of the commonName values) in the certificate
must have a suffix match with the specified value. Suffix match is done
based on full domain name labels, i.e., "example.com" matches
"test.example.com" but not "test-example.com".
Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
Check that SSL_clear_options and SSL_CTX_clear_options are defined
before using them to avoid compilation failures with older OpenSSL
versions that did not include these macros.
Signed-hostap: Jouni Malinen <j@w1.fi>
When using OpenSSL with TLS-based EAP methods, wpa_supplicant can now be
configured to use OCSP stapling (TLS certificate status request) with
ocsp=1 network block parameter. ocsp=2 can be used to require valid OCSP
response before connection is allowed to continue.
hostapd as EAP server can be configured to return cached OCSP response
using the new ocsp_stapling_response parameter and an external mechanism
for updating the response data (e.g., "openssl ocsp ..." command).
This allows wpa_supplicant to verify that the server certificate has not
been revoked as part of the EAP-TLS/PEAP/TTLS/FAST handshake before
actual data connection has been established (i.e., when a CRL could not
be fetched even if a distribution point were specified).
Signed-hostap: Jouni Malinen <j@w1.fi>
Store context for each tls_init() caller, so events are generated for
the correct wpa_s instance. The tls_global variable is retained for
older OpenSSL implementations that may not have app-data for SSL_CTX.
Signed-hostap: Paul Stewart <pstew@chromium.org>
Move the bignum comparison part into the bignum library to allow a
single implementation of rand generation for both ECC and FCC based
groups.
Signed-hostap: Jouni Malinen <j@w1.fi>
The groups 22, 23, and 24 are not based on a safe prime and generate a
prime order subgroup. As such, struct dh_group is also extended to
include the order for previously defined groups (q=(p-1)/2 since these
were based on a safe prime).
Signed-hostap: Jouni Malinen <j@w1.fi>
In addition to the trivial change in adding the new group ientifier,
this required changes to KDF and random number generation to support
cases where the length of the prime in bits is not a multiple of eight.
The binary presentation of the value needs to be shifted so that the
unused most significant bits are the zero padding rather than the extra
bits in the end of the array.
Signed-hostap: Jouni Malinen <j@w1.fi>
In addition to the mandatory group 19 (256-bit random ECP group) add
support for groups 20 (384-bit), 25 (192-bit), and 26 (224-bit).
Signed-hostap: Jouni Malinen <j@w1.fi>
This makes the SAE implementation a bit simpler by not having to build
the bignum for group order during execution.
Signed-hostap: Jouni Malinen <j@w1.fi>
This is a generic AES CCM implementation that can be used for other
purposes than just implementing CCMP, so it fits better in a separate
file in src/crypto.
Signed-hostap: Jouni Malinen <j@w1.fi>
AES uses the same 128-bit block size with 128, 192, 256 bit keys, so use
the fixed block size definition instead of trying to dynamically set the
block size based on key length. This fixes use of 192-bit and 256-bit
AES keys with crypto_cipher_*() API when using the internal AES
implementation.
Signed-hostap: Jouni Malinen <j@w1.fi>
This is otherwise identical to aes_gcm_ae() but does not use the
plain/crypt pointers since no data is encrypted.
Signed-hostap: Jouni Malinen <j@w1.fi>
This adds 192-bit and 256-bit key support to the internal AES
implementation and extends the AES-GCM functions to accept key length to
enable longer AES key use.
Signed-hostap: Jouni Malinen <j@w1.fi>
This is a generic AES GCM and GMAC implementation that can be used for
other purposes than just implementing GCMP, so it fits better in a
separate file in src/crypto.
Signed-hostap: Jouni Malinen <j@w1.fi>
Explicitly validate seed_len to skip memset call with zero length of
copied data at the end of the buffer. This is not really needed, but it
makes the code a bit easier for static analyzers. This is identical to
the commit a9ea17491a but for the OpenSSL
version of the function.
Signed-hostap: Jouni Malinen <j@w1.fi>
Commit c9e08af24f removed the only user of
the special case MD5 use that would be allowed in FIPS mode in
tls_prf_sha1_md5(). Commit 271dbf1594
removed the file from the build, but left the implementation into the
repository. To clean things up even further, remove this functionality
completely since it is not expected to be needed for FIPS mode anymore.
Signed-hostap: Jouni Malinen <j@w1.fi>
The mechanism to figure out key block size based on ssl->read_hash
does not seem to work with OpenSSL 1.0.1, so add an alternative
mechanism to figure out the NAC key size that seems to work at
least with the current OpenSSL 1.0.1 releases.
Signed-hostap: Jouni Malinen <j@w1.fi>
intended-for: hostap-1
This can be used to implement workaround for authentication servers that
do not handle TLS extensions in ClientHello properly.
Signed-hostap: Jouni Malinen <j@w1.fi>
The PKCS5_PBKDF2_HMAC_SHA1() function in OpenSSL 0.9.7 did not mark
the salt parameter const even though it was not modified. Hide the
compiler warning with a type cast when an old OpenSSL version is
used.
Signed-hostap: Jouni Malinen <j@w1.fi>
Only allow the TLS library keying material exporter functionality to be
used for MSK derivation with TLS-based EAP methods to avoid exporting
internal TLS keys from the library.
Signed-hostap: Jouni Malinen <j@w1.fi>
Use SSL_export_keying_material() if possible, i.e., if OpenSSL is
version 1.0.1 or newer and if client random value is used first. This
allows MSK derivation with TLS-based EAP methods (apart from EAP-FAST)
without exporting the master key from OpenSSL.
Signed-hostap: Jouni Malinen <j@w1.fi>
In theory, the SHA1 operation may fail (e.g., if SHA1 becomes disallowed
in some security policies), so better check the return code from
challenge_hash().
Signed-hostap: Jouni Malinen <j@w1.fi>
Do not leave the tls_global context allocated if the global OpenSSL
initialization fails. This was possible in case of FIPS builds if
the FIPS mode cannot be initialized.
Signed-hostap: Jouni Malinen <j@w1.fi>
This bit is set in the code path that handles keys and certs from places
other than OpenSSL authentication engines. Setting this bit causes
authentication to fail when the server provides certificates that don't
match the client certificate authority.
Commit d9cc4646eb added
crypto_hash_{init,update,finish}() wrappers for OpenSSL, but it
assumed the current HMAC API in OpenSSL. This was changed in 0.9.9
to return error codes from the functions while older versions used
void functions. Add support for the older versions, too.
Signed-hostap: Jouni Malinen <j@w1.fi>
Send an "EAP" signal via the new DBus interface under various
conditions during EAP authentication:
- During method selection (ACK and NAK)
- During certificate verification
- While sending and receiving TLS alert messages
- EAP success and failure messages
This provides DBus callers a number of new tools:
- The ability to probe an AP for available EAP methods
(given an identity).
- The ability to identify why the remote certificate was
not verified.
- The ability to identify why the remote peer refused
a TLS connection.
Signed-hostap: Paul Stewart <pstew@chromium.org>
Mark the debug print excessive and print it only in case the entropy
collection is used since this function can get called pretty frequently.
Signed-hostap: Jouni Malinen <j@w1.fi>
Prepare for multiple TLS PRF functions by renaming the SHA1+MD5 based
TLS PRF function to more specific name and add tls_prf() within the
internal TLS implementation as a wrapper for this for now.
Signed-hostap: Jouni Malinen <j@w1.fi>
Currently OpenSSL implementation of TLS in hostapd loads only top
certificate in server certificate file. Change this to try to the
whole chain first and only if that fails, revert to old behavior.
Signed-off-by: Maciej Szmigiero <mhej@o2.pl>
Avoid zero-length memset at the end of the buffer. This is not really
needed, but it makes the code a bit easier for static analyzers.
Signed-hostap: Jouni Malinen <j@w1.fi>
Avoid zero-length memset at the end of the buffer. This is not really
needed, but it makes the code a bit easier for static analyzers.
Signed-hostap: Jouni Malinen <j@w1.fi>
Explicitly validate seed_len to skip memset call with zero length
of copied data at the end of the buffer. This is not really needed,
but it makes the code a bit easier for static analyzers.
Signed-hostap: Jouni Malinen <j@w1.fi>
md->curlen cannot indicate full buffer size here since the buffered
data is processed whenever the full block size of data is available.
Avoid invalid warnings from static analyzers on memcpy() outside the
buffer length by verifying that curlen is smaller than block size.
Signed-hostap: Jouni Malinen <j@w1.fi>
Reassemble partial TLS records to make the internal TLS client
implementation more convenient for stream sockets.
Signed-hostap: Jouni Malinen <j@w1.fi>
The MS-CHAPv1 and MS-CHAPv2 RFCs specify that the password is a string
of "Unicode characters", which for Windows means UCS-2; thus the
password could be any even-length string of up to 512 bytes.
Instead of making the incompatible change of requiring the incoming
password to be UCS-2 encoded, assume the password is UTF-8 encoded and
convert it before using it in NtPasswordHash and
EncryptPwBlockWithPasswordHash.
Signed-off-by: Evan Broder <ebroder@mokafive.com>
These protocols seem to be abandoned: latest IETF drafts have expired
years ago and it does not seem likely that EAP-TTLSv1 would be
deployed. The implementation in hostapd/wpa_supplicant was not complete
and not fully tested. In addition, the TLS/IA functionality was only
available when GnuTLS was used. Since GnuTLS removed this functionality
in 3.0.0, there is no available TLS/IA implementation in the latest
version of any supported TLS library.
Remove the EAP-TTLSv1 and TLS/IA implementation to clean up unwanted
complexity from hostapd and wpa_supplicant. In addition, this removes
any potential use of the GnuTLS extra library.
This fixes some build issues in GnuTLS wrapper to be compatible with
at least following GnuTLS versions: 2.2.5, 2.4.3, 2.6.6, 2.8.6,
2.10.5, 2.12.11, 3.0.3.
eapol_test command line argument -o<file> can now be used to request
the received server certificate chain to be written to the specified
file. The certificates will be written in PEM format. [Bug 391]
Some compilers complain about fwrite calls if the return value is
not checked, so check the value even if it does not really make
much of a difference in this particular case.
This phase1 parameter for TLS-based EAP methods was already supported
with GnuTLS and this commit extends that support for OpenSSL and the
internal TLS implementation.
This can be used to avoid rejection of first two 4-way handshakes every
time hostapd (or wpa_supplicant in AP/IBSS mode) is restarted. A new
command line parameter, -e, can now be used to specify an entropy file
that will be used to maintain the needed state.
This allows keystore:// prefix to be used with client_cert and
private_key configuration parameters.
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
If parsing of the certificate or private key succeeds using any of
the tried encoding types, clear the OpenSSL error queue without
showing the pending errors in debug log since they do not really
provide any useful output and can be confusing.
On Linux, verify that the kernel entropy pool is capable of providing
strong random data before allowing WPA/WPA2 connection to be
established. If 20 bytes of data cannot be read from /dev/random,
force first two 4-way handshakes to fail while collecting entropy
into the internal pool in hostapd. After that, give up on /dev/random
and allow the AP to function based on the combination of /dev/urandom
and whatever data has been collected into the internal entropy pool.
By default, make hostapd and wpa_supplicant maintain an internal
entropy pool that is fed with following information:
hostapd:
- Probe Request frames (timing, RSSI)
- Association events (timing)
- SNonce from Supplicants
wpa_supplicant:
- Scan results (timing, signal/noise)
- Association events (timing)
The internal pool is used to augment the random numbers generated
with the OS mechanism (os_get_random()). While the internal
implementation is not expected to be very strong due to limited
amount of generic (non-platform specific) information to feed the
pool, this may strengthen key derivation on some devices that are
not configured to provide strong random numbers through
os_get_random() (e.g., /dev/urandom on Linux/BSD).
This new mechanism is not supposed to replace proper OS provided
random number generation mechanism. The OS mechanism needs to be
initialized properly (e.g., hw random number generator,
maintaining entropy pool over reboots, etc.) for any of the
security assumptions to hold.
If the os_get_random() is known to provide strong ramdom data (e.g., on
Linux/BSD, the board in question is known to have reliable source of
random data from /dev/urandom), the internal hostapd random pool can be
disabled. This will save some in binary size and CPU use. However, this
should only be considered for builds that are known to be used on
devices that meet the requirements described above. The internal pool
is disabled by adding CONFIG_NO_RANDOM_POOL=y to the .config file.
This commit adds a new wrapper, random_get_bytes(), that is currently
defined to use os_get_random() as is. The places using
random_get_bytes() depend on the returned value being strong random
number, i.e., something that is infeasible for external device to
figure out. These values are used either directly as a key or as
nonces/challenges that are used as input for key derivation or
authentication.
The remaining direct uses of os_get_random() do not need as strong
random numbers to function correctly.
The length of the prime was used incorrectly and this resulted
in WPS DH operation failing whenever the public key ended up having
leading zeros (i.e., about every 1/256th time).
There are no subdirectories in any of these directories or plans
for adding ones. As such, there is no point in running the loop
that does not do anything and can cause problems with some shells.
The returned buffer length was hardcoded to be the prime length
which resulted in shorter results being padded in the end. However,
the results from DH code are supposed to be unpadded (and when used
with WPS, the padding is done in WPS code and it is added to the
beginning of the buffer). This fixes WPS key derivation errors
in about 1/256 of runs ("WPS: Incorrect Authenticator") when using
the internal crypto code.
This allows external programs (e.g., UI) to get more information
about server certificate chain used during TLS handshake. This can
be used both to automatically probe the authentication server to
figure out most likely network configuration and to get information
about reasons for failed authentications.
The follow new control interface events are used for this:
CTRL-EVENT-EAP-PEER-CERT
CTRL-EVENT-EAP-TLS-CERT-ERROR
In addition, there is now an option for matching the server certificate
instead of the full certificate chain for cases where a trusted CA is
not configured or even known. This can be used, e.g., by first probing
the network and learning the server certificate hash based on the new
events and then adding a network configuration with the server
certificate hash after user have accepted it. Future connections will
then be allowed as long as the same server certificate is used.
Authentication server probing can be done, e.g., with following
configuration options:
eap=TTLS PEAP TLS
identity=""
ca_cert="probe://"
Example set of control events for this:
CTRL-EVENT-EAP-STARTED EAP authentication started
CTRL-EVENT-EAP-PROPOSED-METHOD vendor=0 method=21
CTRL-EVENT-EAP-METHOD EAP vendor 0 method 21 (TTLS) selected
CTRL-EVENT-EAP-PEER-CERT depth=0 subject='/C=US/ST=California/L=San Francisco/CN=Server/emailAddress=server@kir.nu' hash=5a1bc1296205e6fdbe3979728efe3920798885c1c4590b5f90f43222d239ca6a
CTRL-EVENT-EAP-TLS-CERT-ERROR reason=8 depth=0 subject='/C=US/ST=California/L=San Francisco/CN=Server/emailAddress=server@kir.nu' err='Server certificate chain probe'
CTRL-EVENT-EAP-FAILURE EAP authentication failed
Server certificate matching is configured with ca_cert, e.g.:
ca_cert="hash://server/sha256/5a1bc1296205e6fdbe3979728efe3920798885c1c4590b5f90f43222d239ca6a"
This functionality is currently available only with OpenSSL. Other
TLS libraries (including internal implementation) may be added in
the future.
Undocumented (at least for the time being) TLS parameters can now
be provided in wpa_supplicant configuration to enable some workarounds
for being able to connect insecurely to some networks. phase1 and
phase2 network parameters can use following options:
tls_allow_md5=1
- allow MD5 signature to be used (disabled by default with GnuTLS)
tls_disable_time_checks=1
- ignore certificate expiration time
For now, only the GnuTLS TLS wrapper implements support for these.
This converts tls_connection_handshake(),
tls_connection_server_handshake(), tls_connection_encrypt(), and
tls_connection_decrypt() to use struct wpa_buf to allow higher layer
code to be cleaned up with consistent struct wpabuf use.
This message from tls_connection_handshake() is not really an error in
most cases, so do not show it if there was indeed no Application Data
available (which is a normal scenario and not an indication of any
error).
This allows libeap.a and libeap.so to be built by merging in multiple
libraries from src subdirectories. In addition, this avoids wasting
extra space and time for local builds.
The following defines are not really needed in most places, so
remove them to clean up source code and build scripts:
EAP_TLS_FUNCS
EAP_TLS_OPENSSL
EAP_TLS_GNUTLS
CONFIG_TLS_INTERNAL
Mainly, this is including header files to get definitions for functions
which is good to verify that the parameters match. None of these are
issues that would have shown as incorrect behavior of the program.
The current MinGW/w32api versions seem to provide all the needed CryptoAPI
functions, so the code for loading these dynamically from the DLL can be
removed.
Need to define the workspace buffer properly to allow compiler to handle
strict aliasing between the incoming unsigned char[64] buffer as an u32
array. The previous version built with strict aliasing enabled can
result in SHA-1 producing incorrect results and consequently, with
4-way handshake failing.
This is based on a report and patch from Dan Williams <dcbw@redhat.com>
but with a different type (the union) used as a fix to avoid needing
extra type casting.
Discovered as part of the investigation of:
https://bugzilla.redhat.com/show_bug.cgi?id=494262#c32
if sha1 is built with gcc without turning off strict aliasing, it will
fail to correctly generate the hashes and will fail its own testcases as
well.
Signed-off-by: Dan Williams <dcbw@redhat.com>
This functionality fits better with src/tls (i.e., internal TLS
implementation), so move it there to make crypto_internal.c more
of a wrapper like other crypto_*.c files.
Private keys can now be used in either unencrypted or encrypted
PKCS #8 encoding. Only the pbeWithMD5AndDES-CBC algorithm (PKCS #5)
is currently supported.
OpenSSL 0.9.7 does not include get_rfc3526_prime_1536() function, so
provide that functionality internally if needed. In addition, make
sha256_vector() building depend on whether SHA256 support is included
in the OpenSSL library. This with CONFIG_INTERNAL_SHA256=y in .config
allows OpenSSL without SHA256 support to be used.
Reorganize the TLS/crypto library segments into a single set of blocks
for each library instead of multiple locations handling library-specific
operations. Group crypto functionality together and get wpa_supplicant
and hostapd Makefile closer to eachother in order to make it easier to
eventually move this into a shared makefile.
Crypto library wrappers can now override the internal DH (group 5)
implementation. As a starting point, this is done with OpenSSL. The
new mechanism is currently available only for WPS (i.e., IKEv2 still
depends on the internal DH implementation).
This allows NSS to be used to derive EAP-TLS/PEAP/TTLS keying material.
NSS requires a patch from
https://bugzilla.mozilla.org/show_bug.cgi?id=507359
to provide the new API. In addition, that patch needs to be modified to
add the 16-bit context length value in SSL_ExportKeyingMaterial() only if
contextlen != 0 in order to match with the EAP-TLS/PEAP/TTLS use cases.
This issue seems to be coming from the unfortunate incompatibility in
draft-ietf-tls-extractor-07.txt (draft-ietf-tls-extractor-00.txt would
have used compatible PRF construction).
At this point, it is unclear how this will be resolved eventually, but
anyway, this shows a mechanism that can be used to implement EAP key
derivation with NSS with a small patch to NSS.
This brings in the first step in adding support for using NSS
(Mozilla Network Security Services) as the crypto and TLS library
with wpa_supplicant. This version is able to run through EAP-PEAP
and EAP-TTLS authentication, but does not yet implement any
certificate/private key configuration. In addition, this does not
implement proper key fetching functions either, so the end result
is not really of much use in real world yet.
The BLOCK_SIZE define can be made more specific by using AES_ prefix and
by moving it to aes.h. After this, most aes-*.c do not really need to
include anything from the internal aes_i.h header file. In other words,
aes_i.h can now be used only for the code that uses the internal AES
block operation implementation and none of the code that can use AES
implementation from an external library do not need to include this
header file.
Better not specify EVP_CIPHER again for the second init call since that
will override key length with the default value. The previous version
was likely to work since most use cases would be likely to use the
default key length. Anyway, better make this handle variable length
ciphers (mainly, RC4), too, just in case it is needed in the future.
This is not really of that much use since rc4_skip() can be used as
easily. In addition, rc4 has caused some symbol conflicts in the past,
so it is easier to live without that as an exported symbol.
wpa_supplicant can now be built with FIPS capable OpenSSL for FIPS mode
operation. Currently, this is only enabling the FIPS mode in OpenSSL
without providing any higher level enforcement in wpa_supplicant.
Consequently, invalid configuration will fail during the authentication
run. Proper configuration (e.g., WPA2-Enterprise with EAP-TLS) allows
the connection to be completed.
Instead of using low level, digest-specific functions, use the generic
EVP interface for digest functions. In addition, report OpenSSL errors
in more detail.
Some crypto libraries can return in these functions (e.g., if a specific
hash function is disabled), so we better provide the caller a chance to
check whether the call failed. The return values are not yet used
anywhere, but they will be needed for future changes.
This removes need for local configuration to ignore *.o and *~
and allows the src/*/.gitignore files to be removed (subdirectories
will inherit the rules from the root .gitignore).
It looks like GnuTLS (at least newer versions) is using random padding
on the application data and the previously used 100 byte extra buffer
for tls_connection_encrypt() calls was not enough to handle all cases.
This resulted in semi-random authentication failures with EAP-PEAP and
EAP-TTLS during Phase 2.
Increase the extra space for encryption from 100 to 300 bytes and add an
error message into tls_gnutls.c to make it easier to notice this issue
should it ever show up again even with the larger buffer.
Updated OpenSSL code for EAP-FAST to use an updated version of the
session ticket overriding API that was included into the upstream
OpenSSL 0.9.9 tree on 2008-11-15 (no additional OpenSSL patch is
needed with that version anymore).
When the TLS handshake had been completed earlier by the server in case of
abbreviated handshake, the output buffer length was left uninitialized. It
must be initialized to zero in this case. This code is used by EAP-FAST
server and the uninitialized length could have caused it to try to send a
very large frame (though, this would be terminated by the 50 roundtrip EAP
limit). This broke EAP-FAST server code in some cases when PAC was used to
establish the tunnel.
The internal TLS implementation can now use both PKCS #1 RSA private key
and PKCS #8 encapsulated RSA private key. PKCS #8 encrypted private key is
not yet supported.
The server handshake processing was still using SSL_read() to get OpenSSL
to perform the handshake. While this works for most cases, it caused some
issues for re-authentication. This is now changed to use SSL_accept() which
is more approriate here since we know that the handshake is still going on
and there will not be any tunneled data available. This resolves some of
the re-authentication issues and makes it possible for the server to notice
if TLS processing fails (SSL_read() did not return an error in many of
these cases while SSL_accept() does).
Set session id context to a unique value in order to avoid fatal errors
when client tries session resumption (SSL_set_session_id_context() must be
called for that to work), but disable session resumption with the unique
value for the time being since not all server side code is ready for it yet
(e.g., EAP-TTLS needs special Phase 2 processing when using abbreviated
handshake).
Changed EAP-TLS server not to call TLS library when processing the final
ACK (empty data) from the client in order to avoid starting a new TLS
handshake with SSL_accept().
It looks like this SSL_set_options() value was added in 0.9.9 and it does
not exist in stable releases of OpenSSL. Fix build by using #ifdef on this
variable before use.
The middle byte of the secret (key for PRF) is shared with key halfs in
case the key length is odd. This does not happen in any of the current
tls_prf() uses, but it's better to fix this function to avoid future issues
should someone end up defining a use that uses an odd length for the key.