The blinding applied to the scalar before modular inversion is
inadequate. Bignum is not constant time/constant trace, side channel
attacks can retrieve the blinded value, factor it (it is smaller than
RSA keys and not guaranteed to have only large prime factors). Then the
key can be recovered by brute force.
Reducing the blinded value makes factoring useless because the adversary
can only recover pk*t+z*N instead of pk*t.
* origin/pr/2860: (26 commits)
config.pl full: exclude MBEDTLS_CTR_DRBG_USE_128_BIT_KEY
mbedtls_hmac_drbg_set_entropy_len() only matters when reseeding
mbedtls_ctr_drbg_set_entropy_len() only matters when reseeding
mbedtls_ctr_drbg_seed: correct maximum for len
Add a note about CTR_DRBG security strength to config.h
Move MBEDTLS_CTR_DRBG_USE_128_BIT_KEY to the correct section
CTR_DRBG: more consistent formatting and wording
CTR_DRBG documentation: further wording improvements
CTR_DRBG: Improve the explanation of security strength
CTR_DRBG: make it easier to understand the security strength
HMAC_DRBG: note that the initial seeding grabs entropy for the nonce
Use standard terminology to describe the personalization string
Do note that xxx_drbg_random functions reseed with PR enabled
Consistently use \c NULL and \c 0
Also mention HMAC_DRBG in the changelog entry
HMAC_DRBG: improve the documentation of the entropy length
HMAC_DRBG documentation improvements clarifications
More CTR_DRBG documentation improvements and clarifications
Fix wording
Remove warning that the previous expanded discussion has obsoleted
...
The documentation of HMAC_DRBG erroneously claimed that
mbedtls_hmac_drbg_set_entropy_len() had an impact on the initial
seeding. This is in fact not the case: mbedtls_hmac_drbg_seed() forces
the entropy length to its chosen value. Fix the documentation.
The documentation of CTR_DRBG erroneously claimed that
mbedtls_ctr_drbg_set_entropy_len() had an impact on the initial
seeding. This is in fact not the case: mbedtls_ctr_drbg_seed() forces
the initial seeding to grab MBEDTLS_CTR_DRBG_ENTROPY_LEN bytes of
entropy. Fix the documentation and rewrite the discussion of the
entropy length and the security strength accordingly.
* origin/pr/2864:
Fix compilation error
Add const to variable
Fix endianity issue when reading uint32
Increase test suite timeout
Reduce stack usage of test_suite_pkcs1_v15
Reduce stack usage of test_suite_pkcs1_v21
Reduce stack usage of test_suite_rsa
Reduce stack usage of test_suite_pk
Explain how MBEDTLS_CTR_DRBG_ENTROPY_LEN is set next to the security
strength statement, rather than giving a partial explanation (current
setting only) in the documentation of MBEDTLS_CTR_DRBG_ENTROPY_LEN.
NIST and many other sources call it a "personalization string", and
certainly not "device-specific identifiers" which is actually somewhat
misleading since this is just one of many things that might go into a
personalization string.
Improve the formatting and writing of the documentation based on what
had been done for CTR_DRBG.
Document the maximum size and nullability of some buffer parameters.
This is a documentation-only change, but one that users who care about
NIST compliance may be interested in, to review if they're using the
module in a compliant way.
Document that a derivation function is used.
Document the security strength of the DRBG depending on the
compile-time configuration and how it is set up. In particular,
document how the nonce specified in SP 800-90A is set.
Mention how to link the ctr_drbg module with the entropy module.
The uint32 is given as a bigendian stream, in the tests, however,
the char buffer that collected the stream read it as is,
without converting it. Add a temporary buffer, to call `greentea_getc()`
8 times, and then put it in the correct endianity for input to `unhexify()`.
Reduce the stack usage of the `test_suite_pkcs1_v21` by reducing the
size of the buffers used in the tests, to a reasonable big enough size,
and change the size sent to the API to sizeof output.
Reduce the stack usage of the `test_suite_rsa` by reducing the
size of the buffers used in the tests, to a reasonable big enough size,
and change the data size to decrypt in the data file.
* State explicit whether several numbers are in bits or bytes.
* Clarify whether buffer pointer parameters can be NULL.
* Explain the value of constants that are dependent on the configuration.
* origin/pr/2826:
Enable MBEDTLS_MEMORY_DEBUG in memory buffer alloc test in all.sh
Remove unnecessary memory buffer alloc and memory backtrace unsets
Disable DTLS proxy tests for MEMORY_BUFFER_ALLOC test
all.sh: restructure memory allocator tests
Add missing dependency in memory buffer alloc set in all.sh
Don't set MBEDTLS_MEMORY_DEBUG through `scripts/config.pl full`
Add cfg dep MBEDTLS_MEMORY_DEBUG->MBEDTLS_MEMORY_BUFFER_ALLOC_C
Add all.sh run with full config and ASan enabled
Add all.sh run with MBEDTLS_MEMORY_BUFFER_ALLOC_C enabled
Update documentation of exceptions for `config.pl full`
Adapt all.sh to removal of buffer allocator from full config
Disable memory buffer allocator in full config
Check dependencies of MBEDTLS_MEMORY_BACKTRACE in check_config.h
With the removal of MBEDTLS_MEMORY_BUFFER_ALLOC_C from the
full config, there are no tests for it remaining in all.sh.
This commit adds a build as well as runs of `make test` and
`ssl-opt.sh` with MBEDTLS_MEMORY_BUFFER_ALLOC_C enabled to all.sh.
