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.
This commit changes the behaviour of mbedtls_ssl_parse_certificate
to make the two authentication modes SSL_VERIFY_REQUIRED and
SSL_VERIFY_OPTIONAL be in the following relationship:
Mode == SSL_VERIFY_REQUIRED
<=> Mode == SSL_VERIFY_OPTIONAL + check verify result
Also, it changes the behaviour to perform the certificate chain
verification even if the trusted CA chain is empty. Previously, the
function failed in this case, even when using optional verification,
which was brought up in #864.
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 RSA private key functions rsa_rsaes_pkcs1_v15_decrypt and
rsa_rsaes_oaep_decrypt put sensitive data (decryption results) on the
stack. Wipe it before returning.
Thanks to Laurent Simon for reporting this issue.
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 test case was generated by modifying our signature code so that it
produces a 7-byte long padding (which also means garbage at the end, so it is
essential to check that the error that is detected first is indeed the
padding rather than the final length check).
Fix a buffer overflow when writting a string representation of an MPI
number to a buffer in hexadecimal. The problem occurs because hex
digits are written in pairs and this is not accounted for in the
calculation of the required buffer size when the number of digits is
odd.
The function ecp_mod_koblitz computed the space for the result of a
multiplication optimally for that specific case, but unfortunately
the function mbedtls_mpi_mul_mpi performs a generic, suboptimal
calculation and needs one more limb for the result. Since the result's
buffer is on the stack, the best case scenario is that the program
stops.
This only happened on 64 bit platforms.
Fixes#569
Fixes a regression introduced by an earlier commit that modified
x509_crt_verify_top() to ensure that valid certificates that are after past or
future valid in the chain are processed. However the change introduced a change
in behaviour that caused the verification flags MBEDTLS_X509_BADCERT_EXPIRED and
MBEDTLS_BADCERT_FUTURE to always be set whenever there is a failure in the
verification regardless of the cause.
The fix maintains both behaviours:
* Ensure that valid certificates after future and past are verified
* Ensure that the correct verification flags are set.
Modifies the function mbedtls_x509_crl_parse() to ensure that a CRL in PEM
format with trailing characters after the footer does not result in the
execution of an infinite loop.
Fix potential integer overflows in the function mbedtls_base64_decode().
This overflow would mainly be exploitable in 32-bit systems and could
cause buffer bound checks to be bypassed.
Fix potential integer overflows in the following functions:
* mbedtls_md2_update() to be bypassed and cause
* mbedtls_cipher_update()
* mbedtls_ctr_drbg_reseed()
This overflows would mainly be exploitable in 32-bit systems and could
cause buffer bound checks to be bypassed.
Fix potential integer overflows in the function mbedtls_base64_decode().
This overflow would mainly be exploitable in 32-bit systems and could
cause buffer bound checks to be bypassed.
Fix potential integer overflows in the following functions:
* mbedtls_md2_update() to be bypassed and cause
* mbedtls_cipher_update()
* mbedtls_ctr_drbg_reseed()
This overflows would mainly be exploitable in 32-bit systems and could
cause buffer bound checks to be bypassed.
This PR fixes a number of unused variable/function compilation warnings
that arise when using a config.h that does not define the macro
POLARSSL_PEM_PARSE_C.
This patch introduces some additional checks in the PK module for 64-bit
systems only. The problem is that the API functions in the PK
abstraction accept a size_t value for the hashlen, while the RSA module
accepts an unsigned int for the hashlen. Instead of silently casting
size_t to unsigned int, this change checks whether the hashlen overflows
an unsigned int and returns an error.
This change fixes a regression introduced by an earlier commit that
modified x509_crt_verify_top() to ensure that valid certificates
that are after past or future valid in the chain are processed. However
the change introduced a change in behaviour that caused the
verification flags BADCERT_EXPIRED and BADCERT_FUTURE to always be set
whenever there is a failure in the verification regardless of the cause.
The fix maintains both behaviours:
* Ensure that valid certificates after future and past are verified
* Ensure that the correct verification flags are set.
To do so, a temporary pointer to the first future or past valid
certificate is maintained while traversing the chain. If a truly valid
certificate is found then that one is used, otherwise if no valid
certificate is found and the end of the chain is reached, the program
reverts back to using the future or past valid certificate.
This patch modifies the function mbedtls_x509_crl_parse() to ensure
that a CRL in PEM format with trailing characters after the footer does
not result in the execution of an infinite loop.
