Add output size parameter to signature functions

The functions mbedtls_pk_sign(), mbedtls_pk_sign_restartable(),
mbedtls_ecdsa_write_signature() and mbedtls_ecdsa_write_signature_restartable()
now take an extra parameter indicating the size of the output buffer for the
signature.

No change to RSA because for RSA, the output size is trivial to calculate.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2021-06-22 00:09:00 +02:00
parent 1fed4b8324
commit f00f152444
19 changed files with 131 additions and 81 deletions

View file

@ -0,0 +1,9 @@
Extra parameter for the output buffer size
------------------------------------------
The following functions now take an extra parameter indicating the size of the output buffer:
* `mbedtls_ecdsa_write_signature()`, `mbedtls_ecdsa_write_signature_restartable()`
* `mbedtls_pk_sign()`, `mbedtls_pk_sign_restartable()`
The requirements for the output buffer have not changed, but passing a buffer that is too small now reliably causes the functions to return an error, rather than overflowing the buffer.