There are situations in which it is not clear what message to expect
next. For example, the message following the ServerHello might be
either a Certificate, a ServerKeyExchange or a CertificateRequest. We
deal with this situation in the following way: Initially, the message
processing function for one of the allowed message types is called,
which fetches and decodes a new message. If that message is not the
expected one, the function returns successfully (instead of throwing
an error as usual for unexpected messages), and the handshake
continues to the processing function for the next possible message. To
not have this function fetch a new message, a flag in the SSL context
structure is used to indicate that the last message was retained for
further processing, and if that's set, the following processing
function will not fetch a new record.
This commit simplifies the usage of this message-retaining parameter
by doing the check within the record-fetching routine instead of the
specific message-processing routines. The code gets cleaner this way
and allows retaining messages to be used in other situations as well
without much effort. This will be used in the next commits.
By default, keep allowing SHA-1 in key exchange signatures. Disabling
it causes compatibility issues, especially with clients that use
TLS1.2 but don't send the signature_algorithms extension.
SHA-1 is forbidden in certificates by default, since it's vulnerable
to offline collision-based attacks.
There is now one test case to validate that SHA-1 is rejected in
certificates by default, and one test case to validate that SHA-1 is
supported if MBEDTLS_TLS_DEFAULT_ALLOW_SHA1 is #defined.
Default to forbidding the use of SHA-1 in TLS where it is unsafe: for
certificate signing, and as the signature hash algorithm for the TLS
1.2 handshake signature. SHA-1 remains allowed in HMAC-SHA-1 in the
XXX_SHA ciphersuites and in the PRF for TLS <= 1.1.
For easy backward compatibility for use in controlled environments,
turn on the MBEDTLS_TLS_DEFAULT_ALLOW_SHA1 compiled-time option.
* hanno/sig_hash_compatibility:
Improve documentation
Split long lines
Remember suitable hash function for any signature algorithm.
Introduce macros and functions to characterize certain ciphersuites.
Note that the configuration structure must remain accessible. The
previous wording could have been taken as implying that it's ok to
change the structure but changes wouldn't be taken into account.
Also note that calling this function twice is not supported (it would
at least be a memory leak).
This patch modifies the following 2 functions in the AES module to
change the return type from void to int:
* mbedtls_aes_encrypt() -> mbedtls_internal_aes_encrypt()
* mbedtls_aes_decrypt() -> mbedtls_internal_aes_decrypt()
This change is necessary to allow users of MBEDTLS_AES_ALT,
MBEDTLS_AES_DECRYPT_ALT and MBEDTLS_AES_ENCRYPT_ALT to return an error
code when replacing the default with their own implementation, e.g.
a hardware crypto accelerator.
According to RFC5246 the server can indicate the known Certificate
Authorities or can constrain the aurhorisation space by sending a
certificate list. This part of the message is optional and if omitted,
the client may send any certificate in the response.
The previous behaviour of mbed TLS was to always send the name of all the
CAs that are configured as root CAs. In certain cases this might cause
usability and privacy issues for example:
- If the list of the CA names is longer than the peers input buffer then
the handshake will fail
- If the configured CAs belong to third parties, this message gives away
information on the relations to these third parties
Therefore we introduce an option to suppress the CA list in the
Certificate Request message.
Providing this feature as a runtime option comes with a little cost in
code size and advantages in maintenance and flexibility.
This commit changes `ssl_parse_signature_algorithms_ext` to remember
one suitable ( := supported by client and by our config ) hash
algorithm per signature algorithm.
It also modifies the ciphersuite checking function
`ssl_ciphersuite_match` to refuse a suite if there
is no suitable hash algorithm.
Finally, it adds the corresponding entry to the ChangeLog.
The routine `mbedtls_ssl_write_server_key_exchange` heavily depends on
what kind of cipher suite is active: some don't need a
ServerKeyExchange at all, some need (EC)DH parameters but no server
signature, some require both. Each time we want to restrict a certain
piece of code to some class of ciphersuites, it is guarded by a
lengthy concatentation of configuration checks determining whether at
least one of the relevant cipher suites is enabled in the config; on
the code level, it is guarded by the check whether one of these
cipher suites is the active one.
To ease readability of the code, this commit introduces several helper
macros and helper functions that can be used to determine whether a
certain class of ciphersuites (a) is active in the config, and
(b) contains the currently present ciphersuite.
With this commit the Elliptic Curve Point interface is rewised. Two
compile time options has been removed to simplify the interface and
the function names got a new prefix that indicates that these functions
are for internal use and not part of the public interface.
The primary use case behind providing an abstraction layer to enable
alternative Elliptic Curve Point arithmetic implementation, is making
use of cryptographic acceleration hardware if it is present.
To provide thread safety for the hardware accelerator we need a mutex
to guard it.
The compile time macros enabling the initialisation and deinitialisation
in the alternative Elliptic Curve Point arithmetic implementation had
names that did not end with '_ALT' as required by check-names.sh.
When provided with an empty line, mpi_read_file causes a numeric
underflow resulting in a stack underflow. This commit fixes this and
adds some documentation to mpi_read_file.
The modular inversion function hangs when provided with the modulus 1. This commit refuses this modulus with a BAD_INPUT error code. It also adds a test for this case.
In the ecdsa.c sample application we don't use hashing, we use ecdsa
directly on a buffer containing plain text. Although the text explains
that it should be the message hash it still can be confusing.
Any misunderstandings here are potentially very dangerous, because ECDSA
truncates the message hash if necessary and this can lead to trivial
signature forgeries if the API is misused and the message is passed
directly to the function without hashing.
This commit adds a hash computation step to the ecdsa.c sample
application and clarification to the doxygen documentation of the
ECDSA functions involved.
Fix an incorrect condition in ssl_check_ctr_renegotiate() that compared
64 bits of record counter instead of 48 bits as described in RFC 6347
Section 4.3.1. This would cause the function's return value to be
occasionally incorrect and the renegotiation routines to be triggered
at unexpected times.
Fix an incorrect condition in ssl_check_ctr_renegotiate() that compared
64 bits of record counter instead of 48 bits as described in RFC 6347
Section 4.3.1. This would cause the function's return value to be
occasionally incorrect and the renegotiation routines to be triggered
at unexpected times.
Fixes many typos, and errors in comments.
* Clarifies many comments
* Grammar correction in config.pl help text
* Removed comment about MBEDTLS_X509_EXT_NS_CERT_TYPE.
* Comment typo fix (Dont => Don't)
* Comment typo fix (assure => ensure)
* Comment typo fix (byes => bytes)
* Added citation for quoted standard
* Comment typo fix (one complement => 1's complement)
The is some debate about whether to prefer "one's complement", "ones'
complement", or "1's complement". The more recent RFCs related to TLS
(RFC 6347, RFC 4347, etc) use " 1's complement", so I followed that
convention.
* Added missing ")" in comment
* Comment alignment
* Incorrect comment after #endif
Fix implementation and documentation missmatch for the function
arguments to mbedtls_gcm_finish(). Also, removed redundant if condition
that always evaluates to true.
Minor fixes following review including:
* formatting changes including indentation and code style
* corrections
* removal of debug code
* clarification of code through variable renaming
* memory leak
* compiler warnings
Change the CMAC interface to match the mbedtls_md_hmac_xxxx() interface. This
changes the overall design of the CMAC interface to make it more consistent with
the existing HMAC interface, and will allow incremental updates of input data
rather than requiring all data to be presented at once, which is what the
current interface requires.
The library/net.c and its corresponding include/mbedtls/net.h file are
renamed to library/net_sockets.c and include/mbedtls/net_sockets.h
respectively. This is to avoid naming collisions in projects which also
have files with the common name 'net'.
Allow the size of the entry_name character array in x509_crt.c to be
configurable through a macro in config.h. entry_name holds a
path/filename string. The macro introduced in
MBEDTLS_X509_MAX_FILE_PATH_LEN.
Ensure that the entropy self test always fails whenever
MBEDTLS_TEST_NULL_ENTROPY is defined. This is because the option is
meant to be for testing and development purposes rather than production
quality software. Also, this patch enhances the documentation for
mbedtls_entropy_source_self_test() and mbedtls_entropy_self_test().
Instead of polling the hardware entropy source a single time and
comparing the output with itself, the source is polled at least twice
and make sure that the separate outputs are different.
The self test is a quick way to check at startup whether the entropy
sources are functioning correctly. The self test only polls 8 bytes
from the default entropy source and performs the following checks:
- The bytes are not all 0x00 or 0xFF.
- The hardware does not return an error when polled.
- The entropy does not provide data in a patter. Only check pattern
at byte, word and long word sizes.
* Check time platform abstraction macro definitions
This patch adds some checks to check_config.h to ensure that macro
definitions for the time platform abstraction are acceptable. In this
case the requirements are:
- MBEDTLS_PLATFORM_C and MBEDTLS_HAVE_TIME must be defined whenever
MBEDTLS_PLATFORM_TIME_ALT, MBEDTLS_PLATFORM_TIME_TYPE_MACRO or
MBEDTLS_PLATFORM_TIME_MACRO is defined.
- MBEDTLS_PLATFORM_STD_TIME and MBEDTLS_PLATFORM_TIME_ALT cannot be
defined simultaneously with MBEDTLS_PLATFORM_TIME_TYPE_MACRO or
MBEDTLS_PLATFORM_TIME_MACRO.
- MBEDTLS_HAVE_TIME and MBEDTLS_PLATFORM_TIME_ALT must be defined
whenever MBEDTLS_PLATFORM_STD_TIME is defined.
* Document requirements for time abstraction macros
Document that time platform abstraction macros
MBEDTLS_PLATFORM_TIME_ALT, MBEDTLS_PLATFORM_TIME_MACRO,
MBEDTLS_PLATFORM_TIME_TYPE_MACRO and MBEDTLS_PLATFORM_STD_TIME require
MBEDTLS_HAVE_TIME to be defined in config.h.
* Fix requires comment in config.h
* Split preprocessor condition for simplicity
Separates platform time abstraction into it's own header from the
general platform abstraction as both depend on different build options.
(MBEDTLS_PLATFORM_C vs MBEDTLS_HAVE_TIME)
target_config.h is no longer needed for target/platform configurations so
this change removes it from the default and platform configurations for mbed
builds.
Update the NV entropy seed before generating any entropy for outside
use. The reason this is triggered here and not in mbedtls_entropy_init(),
is that not all entropy sources mights have been added at that time.
Introduces mbedtls_nv_seed_read() and mbedtls_nv_seed_write().
The platform-layer functions are only available when
MBEDTLS_ENTROPY_NV_SEED is enabled.
Add a switch that turns entropy collecting off entirely, but enables
mbed TLS to run in an entirely unsafe mode. Enables to test mbed TLS
on platforms that don't have their entropy sources integrated yet.
On x32, pointers are only 4-bytes wide and need to be loaded using the "movl"
instruction instead of "movq" to avoid loading garbage into the register.
The MULADDC routines for x86-64 are adjusted to work on x32 as well by getting
gcc to load all the registers for us in advance (and storing them later) by
using better register constraints. The b, c, D and S constraints correspond to
the rbx, rcx, rdi and rsi registers respectively.
The callback typedefs defined for mbedtls_ssl_set_bio() and
mbedtls_ssl_set_timer_cb() were not used consistently where the callbacks were
referenced in structures or in code.
- document why we made that choice
- remove the two TODOs about checking hash and CA
- remove the code that parsed certificate_type: it did nothing except store
the selected type in handshake->cert_type, but that field was never accessed
afterwards. Since handshake_params is now an internal type, we can remove that
field without breaking the ABI.
Previously it was failing with errors about headers not found, which is
suboptimal in terms of clarity. Now give a clean error with pointer to the
documentation.
Do the checks in the .c files rather than check_config.h as it keeps them
closer to the platform-specific implementations.
The previous documentation was not explicit about what was expected of the
callbacks - the user had to infer that from the descriptions in net.h or
timing.h, and it was not clear what was part of the calling convention and
what was specific to our implementation.
When we use the same documentation for a list of #defines, we used to use a
generic name in the \def command. Use the first name of the list instead so
that doxygen stops complaining, and mention the generic name in the longer
description.
This is not entirely satisfactory as the full list of macros will not be
included in the generated doc, but it's still an improvement as at least the
first macro is documented now, with a hint that there are others.
On x32, pointers are only 4-bytes wide and need to be loaded using the "movl"
instruction instead of "movq" to avoid loading garbage into the register.
The MULADDC routines for x86-64 are adjusted to work on x32 as well by getting
gcc to load all the registers for us in advance (and storing them later) by
using better register constraints. The b, c, D and S constraints correspond to
the rbx, rcx, rdi and rsi registers respectively.
When the peer retransmits a flight with many record in the same datagram, and
we already saw one of the records in that datagram, we used to drop the whole
datagram, resulting in interoperability failure (spurious handshake timeouts,
due to ignoring record retransmitted by the peer) with some implementations
(issues with Chrome were reported).
So in those cases, we want to only drop the current record, and look at the
following records (if any) in the same datagram. OTOH, this is not something
we always want to do, as sometime the header of the current record is not
reliable enough.
This commit introduces a new return code for ssl_parse_header() that allows to
distinguish if we should drop only the current record or the whole datagram,
and uses it in mbedtls_ssl_read_record()
fixes#345
fixes#310
Actually all key exchanges that use a certificate use signatures too, and
there is no key exchange that uses signatures but no cert, so merge those two
flags.
* development: (73 commits)
Bump yotta dependencies version
Fix typo in documentation
Corrected misleading fn description in ssl_cache.h
Corrected URL/reference to MPI library
Fix yotta dependencies
Fix minor spelling mistake in programs/pkey/gen_key.c
Bump version to 2.1.2
Fix CVE number in ChangeLog
Add 'inline' workaround where needed
Fix references to non-standard SIZE_T_MAX
Fix yotta version dependencies again
Upgrade yotta dependency versions
Fix compile error in net.c with musl libc
Add missing warning in doc
Remove inline workaround when not useful
Fix macroization of inline in C++
Changed attribution for Guido Vranken
Merge of IOTSSL-476 - Random malloc in pem_read()
Fix for IOTSSL-473 Double free error
Fix potential overflow in CertificateRequest
...
Conflicts:
include/mbedtls/ssl_internal.h
library/ssl_cli.c
- "master secret" is the usual name
- move key block arg closer to the related lengths
- document lengths
Also fix some trailing whitespace while at it
This is more consistent, as it doesn't make any sense for a user to be able to
set up an EC J-PAKE password with TLS if the corresponding key exchange is
disabled.
Arguably this is what we should de for other key exchanges as well instead of
depending on ECDH_C etc, but this is an independent issue, so let's just do
the right thing with the new key exchange and fix the other ones later. (This
is a marginal issue anyway, since people who disable all ECDH key exchange are
likely to also disable ECDH_C in order to minimize footprint.)
The Thread spec says we need those for EC J-PAKE too.
However, we won't be using the information, so we can skip the parsing
functions in an EC J-PAKE only config; keep the writing functions in order to
comply with the spec.
Don't depend on srv.c in config.h, but add explicit checks. This is more
in line with other options that only make sense server-side, and also it
allows to test full config minus srv.c more easily.
Use a custom function that minimally parses the message an creates a reply
without the overhead of a full SSL context.
Also fix dependencies: needs DTLS_HELLO_VERIFY for the cookie types, and let's
also depend on SRV_C as is doesn't make sense on client.
This is not very useful for TLS as mbedtls_ssl_write() will automatically
fragment and return the length used, and the application should check for that
anyway, but this is useful for DTLS where mbedtls_ssl_write() returns an
error, and the application needs to be able to query the maximum length
instead of just guessing.
We're getting build errors with Clang 3.5.0 on our Debian Jessie buildslave:
library/padlock.c:99:10: error: inline assembly requires more registers than available
This is particularly problematic when calling FD_SET( -1, ... ), but let's
check it in all functions.
This was introduced with the new API and the fact the net_free() now sets the
internal fd to -1 in order to mark it as closed: now using this information.
We document that either of recv or recv_timeout may be NULL, but for TLS we
always used recv... Thanks Coverity for catching that.
(Not remotely trigerrable: local configuration.)
Also made me notice net_recv_timeout didn't do its job properly.
While at it, fix the following:
- on server with RSA_PSK, we don't want to set flags (client auth happens via
the PSK, no cert is expected).
- use safer tests (eg == OPTIONAL vs != REQUIRED)
Just applying rename.pl with this file:
mbedtls_cipher_get_key_size mbedtls_cipher_get_key_bitlen
mbedtls_pk_get_size mbedtls_pk_get_bitlen
MBEDTLS_BLOWFISH_MIN_KEY MBEDTLS_BLOWFISH_MIN_KEY_BITS
MBEDTLS_BLOWFISH_MAX_KEY MBEDTLS_BLOWFISH_MAX_KEY_BITS
- allows to express 'none' or 'all' more easily than lists
- more compact and easier to declare statically
- easier to check too
Only drawback: if we ever have more than 32 curves, we'll need an ABI change to
make that field a uint64_t.
Things that are not guaranteed by the standard but should be true of all
platforms of interest to us:
- 8-bit chars
- NULL pointers represented by all-bits-zero
* gmtime_r is not standard so -std=c99 warns about it
* Anyway we need global mutexes in the threading layer, so better depend only
on that, rather that global mutexes + some _r functions
- DTLS_HELLO_VERIFY no longer depends on SRV_C
- SSL_COOKIE_C no longer depends on DTLS_HELLO_VERIFY
Not that much work for us, and easier on users (esp. since it allows just
disabling SRV_C alone).
- Only the server needs to generate/parse tickets
- Only the client needs to store them
Also adjust prototype of ssl_conf_session_tickets() while at it.
Initially thought it would be per-connection, but since max_version is in conf
too, and you need to lower that for a fallback connection, the fallback flag
should be in the same place
A simple series of sed invocations.
This is the first step, purely internal changes. The conf substructure is not
ready to be shared between contexts yet.
