lib/mbedtls
1
0
Fork 0
mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2025-07-30 22:43:08 +03:00
Code Activity

Immediately reject 0-size signature buffer when signing

Browse Source 
In psa_asymmetric_sign, immediately reject an empty signature buffer.
This can never be right.

Add test cases (one RSA and one ECDSA).

Change the SE HAL mock tests not to use an empty signature buffer.
This commit is contained in:
Gilles Peskine
2019-09-12 22:05:59 +02:00
parent f916894ef3
commit 4019f0e914
3 changed files with 26 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
library/psa_crypto.c
View File

@ -3347,6 +3347,12 @@ psa_status_t psa_asymmetric_sign( psa_key_handle_t handle,
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
*signature_length = signature_size;
/* Immediately reject a zero-length signature buffer. This guarantees
* that signature must be a valid pointer. (On the other hand, the hash
* buffer can in principle be empty since it doesn't actually have
* to be a hash.) */
if( signature_size == 0 )
return( PSA_ERROR_BUFFER_TOO_SMALL );
status = psa_get_key_from_slot( handle, &slot, PSA_KEY_USAGE_SIGN, alg );
if( status != PSA_SUCCESS )
@ -3422,7 +3428,7 @@ exit:
if( status == PSA_SUCCESS )
memset( signature + *signature_length, '!',
signature_size - *signature_length );
else if( signature_size != 0 )
else
memset( signature, '!', signature_size );
/* If signature_size is 0 then we have nothing to do. We must not call
* memset because signature may be NULL in this case. */