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

Allow importing Montgomery public keys in PSA Crypto

Browse Source 
PSA Crypto was checking the byte length of a to-be-imported public ECP key
against the expected length for Weierstrass keys, forgetting that
Curve25519/Curve448 exists.

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
This commit is contained in:
Steven Cooreman
2020-07-30 15:04:07 +02:00
parent 7f39187d6b
commit 3fa684ed91
4 changed files with 49 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
library/psa_crypto.c
View File

@ -732,19 +732,34 @@ static psa_status_t psa_load_ecp_representation( const uint8_t *buffer,
mbedtls_ecp_group_id grp_id = MBEDTLS_ECP_DP_NONE;
psa_status_t status;
mbedtls_ecp_keypair *ecp = NULL;
size_t curve_size = size;
size_t curve_size;
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) )
{
/* A public key is represented as:
* - The byte 0x04;
* - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
* - `y_P` as a `ceiling(m/8)`-byte string, big-endian.
* So its data length is 2m+1 where n is the key size in bits.
*/
if( ( size & 1 ) == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
curve_size = size / 2;
if( PSA_KEY_TYPE_ECC_GET_FAMILY( type ) == PSA_ECC_FAMILY_MONTGOMERY )
{
/* A Montgomery public key is represented as its raw
* compressed public point.
*/
curve_size = size;
}
else
{
/* A Weierstrass public key is represented as:
* - The byte 0x04;
* - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
* - `y_P` as a `ceiling(m/8)`-byte string, big-endian.
* So its data length is 2m+1 where n is the key size in bits.
*/
if( ( size & 1 ) == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
curve_size = size / 2;
}
}
else
{
/* Private keys are represented as the raw private value */
curve_size = size;
}
/* Allocate and initialize a key representation. */