This patch modifies the documentation for mbedtls_ssl_write() to allow
0 as a valid return value as this is the correct number of bytes that
should be returned when an empty TLS Application record is sent.
The TLS layer is checking for mode, such as GCM, CCM, CBC, STREAM. ChachaPoly
needs to have its own mode, even if it's used just one cipher, in order to
allow consistent handling of mode in the TLS layer.
* development: (182 commits)
Change the library version to 2.11.0
Fix version in ChangeLog for fix for #552
Add ChangeLog entry for clang version fix. Issue #1072
Compilation warning fixes on 32b platfrom with IAR
Revert "Turn on MBEDTLS_SSL_ASYNC_PRIVATE by default"
Fix for missing len var when XTS config'd and CTR not
ssl_server2: handle mbedtls_x509_dn_gets failure
Fix harmless use of uninitialized memory in ssl_parse_encrypted_pms
SSL async tests: add a few test cases for error in decrypt
Fix memory leak in ssl_server2 with SNI + async callback
SNI + SSL async callback: make all keys async
ssl_async_resume: free the operation context on error
ssl_server2: get op_name from context in ssl_async_resume as well
Clarify "as directed here" in SSL async callback documentation
SSL async callbacks documentation: clarify resource cleanup
Async callback: use mbedtls_pk_check_pair to compare keys
Rename mbedtls_ssl_async_{get,set}_data for clarity
Fix copypasta in the async callback documentation
SSL async callback: cert is not always from mbedtls_ssl_conf_own_cert
ssl_async_set_key: detect if ctx->slots overflows
...
The XTS configuration option MBEDTLS_CIPHER_MODE_XTS currently only enables
XTS for AES. So, don't say it enables XTS for "symmetric ciphers", just
AES. This helps to avoid being misleading.
mbedtls_aes_crypt_xts() currently takes a `bits_length` parameter, unlike
the other block modes. Change the parameter to accept a bytes length
instead, as the `bits_length` parameter is not actually ever used in the
current implementation.
Add a new context structure for XTS. Adjust the API for XTS to use the new
context structure, including tests suites and the benchmark program. Update
Doxgen documentation accordingly.
AES-XEX is a building block for other cryptographic standards and not yet a
standard in and of itself. We'll just provide the standardized AES-XTS
algorithm, and not AES-XEX. The AES-XTS algorithm and interface provided
can be used to perform the AES-XEX algorithm when the length of the input
is a multiple of the AES block size.
XTS mode is fully known as "xor-encrypt-xor with ciphertext-stealing".
This is the generalization of the XEX mode.
This implementation is limited to an 8-bits (1 byte) boundary, which
doesn't seem to be what was thought considering some test vectors [1].
This commit comes with tests, extracted from [1], and benchmarks.
Although, benchmarks aren't really nice here, as they work with a buffer
of a multiple of 16 bytes, which isn't a challenge for XTS compared to
XEX.
[1] http://csrc.nist.gov/groups/STM/cavp/documents/aes/XTSTestVectors.zip
XEX mode, known as "xor-encrypt-xor", is the simple case of the XTS
mode, known as "XEX with ciphertext stealing". When the buffers to be
encrypted/decrypted have a length divisible by the length of a standard
AES block (16), XTS is exactly like XEX.
When MBEDTLS_PLATFORM_MEMORY is defined but MBEDTLS_PLATFORM_FREE_MACRO or
MBEDTLS_PLATFORM_CALLOC_MACRO are not defined then the actual functions
used to allocate and free memory are stored in function pointers.
These pointers are exposed to the caller, and it means that the caller
and the library have to share a data section.
In TF-A, we execute in a very constrained environment, where some images
are executed from ROM and other images are executed from SRAM. The
images that are executed from ROM cannot be modified. The SRAM size
is very small and we are moving libraries to the ROM that can be shared
between the different SRAM images. These SRAM images could import all the
symbols used in mbedtls, but it would create an undesirable hard binary
dependency between the different images. For this reason, all the library
functions in ROM are accesed using a jump table whose base address is
known, allowing the images to execute with different versions of the ROM.
This commit changes the function pointers to actual functions,
so that the SRAM images only have to use the new exported symbols
(mbedtls_calloc and mbedtls_free) using the jump table. In
our scenario, mbedtls_platform_set_calloc_free is called from
mbedtls_memory_buffer_alloc_init which initializes the function pointers
to the internal buffer_alloc_calloc and buffer_alloc_free functions.
No functional changes to mbedtls_memory_buffer_alloc_init.
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>
* development: (97 commits)
Updated version number to 2.10.0 for release
Add a disabled CMAC define in the no-entropy configuration
Adapt the ARIA test cases for new ECB function
Fix file permissions for ssl.h
Add ChangeLog entry for PR#1651
Fix MicroBlaze register typo.
Fix typo in doc and copy missing warning
Fix edit mistake in cipher_wrap.c
Update CTR doc for the 64-bit block cipher
Update CTR doc for other 128-bit block ciphers
Slightly tune ARIA CTR documentation
Remove double declaration of mbedtls_ssl_list_ciphersuites
Update CTR documentation
Use zeroize function from new platform_util
Move to new header style for ALT implementations
Add ifdef for selftest in header file
Fix typo in comments
Use more appropriate type for local variable
Remove useless parameter from function
Wipe sensitive info from the stack
...
Motivation is similar to NO_UDBL_DIVISION.
The alternative implementation of 64-bit mult is straightforward and aims at
obvious correctness. Also, visual examination of the generate assembly show
that it's quite efficient with clang, armcc5 and arm-clang. However current
GCC generates fairly inefficient code for it.
I tried to rework the code in order to make GCC generate more efficient code.
Unfortunately the only way to do that is to get rid of 64-bit add and handle
the carry manually, but this causes other compilers to generate less efficient
code with branches, which is not acceptable from a side-channel point of view.
So let's keep the obvious code that works for most compilers and hope future
versions of GCC learn to manage registers in a sensible way in that context.
See https://bugs.launchpad.net/gcc-arm-embedded/+bug/1775263
Clarify the roles of the buffer parameter and their sizes.
Remove a statement about input size restrictions that only applies to
mbedtls_gcm_update, not to the whole-message functions.
Document the possible error codes.
Warn that mbedtls_gcm_crypt_and_tag in decrypt mode does not
authenticate the data and recommend using mbedtls_gcm_auth_decrypt
instead.
Allowing DECRYPT with crypt_and_tag is a risk as people might fail to check
the tag correctly (or at all). So force them to use auth_decrypt() instead.
See also https://github.com/ARMmbed/mbedtls/pull/1668
