Further, state explicitly that wrong key types need not be supported by alternative RSA implementations, and that those
may instead return the newly introduced error code MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION.
This commit returns to using constant macros instead of global variables for the DHM group constants. Further, macros
providing the binary encoding of the primes from RFC 3526 and RFC 7919 are added. The hex-string macros are deprecated.
Our README claims that we only use basic Make functionality, but in
fact GNU make is required for conditional compilation. Document this.
Addresses issue #967
As the new PKCS v1.5 verification function opaquely compares an expected encoding to the given one, it cannot
distinguish multiple reasons of failure anymore and instead always returns MBEDTLS_ERR_RSA_VERIFY_FAILED. This
necessitates some modifications to the expected return values of some tests verifying signatures with bad padding.
This commit modifies the PKCS1 v1.5 signature verification function `mbedtls_rsa_rsassa_pkcs1_v15_verify` to prepare the
expected PKCS1-v1.5-encoded hash using the function also used by the signing routine `mbedtls_rsa_rsassa_pkcs1_v15_sign`
and comparing it to the provided byte-string afterwards. This comes at the benefits of (1) avoiding any error-prone
parsing, (2) removing the dependency of the RSA module on the ASN.1 parsing module, and (3) reducing code size.
This commit moves the code preparing PKCS1 v1.5 encoded hashes from `mbedtls_rsa_rsassa_pkcs1_v15_sign` to a separate
non-public function `rsa_rsassa_pkcs1_v15_encode`. This code-path will then be re-used by the signature verification function
`mbetls_rsa_rsassa_pkcs1_v15_verify` in a later commit.
This commit adds some tests to the RSA test suite verifying that RSA PKCS-v15 signatures with non-reduced length
encodings are refuted. Details are provided via comments in the test suite data file.
Original intention was to be allowed to perform in-place operations like changing the byte-order before importing
parameters into an HSM. Now a copy is needed in this case, but there's no more danger of a user expecting the arguments
to be left untouched.
Document explicitly that `mbedtls_rsa_check_privkey` and `mbedtls_rsa_complete` succeeding does not guarantee the
consistency of the underlying RSA private key but only that enough information is present to perform a private key
operation.
