TeamHepta/mbedtls
1
0
Fork 0
mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2026-05-09 03:04:24 +02:00
Code Issues Packages Projects Releases Wiki Activity

PK: validate type upfront when copying from PSA

Browse Source 
The type was validated near the end of the function when importing, but
if makes more sense to validate upfront before we possibly allocate a
buffer, export the key to it etc.

This also guarantees a sensible error value without requiring a special
case when exporting on the stack.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
This commit is contained in:
Manuel Pégourié-Gonnard
2026-02-12 11:52:19 +01:00
parent 70454dc75b
commit 925341971d
1 changed files with 22 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
library/pk.c
View File

@@ -608,7 +608,8 @@ int mbedtls_pk_get_psa_attributes(const mbedtls_pk_context *pk,
* - using a macro in multiple places results in multiple copies of the code;
* - this function only handles key types supported in PK.
*
* Return 0 on unexpected types. Callers need to check for that value.
* WARNING: callers need to ensure the type is supported before calling this
* function, possibly by calling is_valid_for_pk().
*/
static size_t pk_export_max_size(psa_key_type_t key_type, size_t bits)
{
@@ -937,6 +938,22 @@ int mbedtls_pk_import_into_psa(const mbedtls_pk_context *pk,
}
}
static int is_valid_for_pk(psa_key_type_t key_type)
{
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)
if (PSA_KEY_TYPE_IS_ECC(key_type)) {
return 1;
}
#endif
#if defined(MBEDTLS_RSA_C)
if (key_type == PSA_KEY_TYPE_RSA_PUBLIC_KEY ||
key_type == PSA_KEY_TYPE_RSA_KEY_PAIR) {
return 1;
}
#endif
return 0;
}
static int copy_from_psa(mbedtls_svc_key_id_t key_id,
mbedtls_pk_context *pk,
int public_only)
@@ -965,6 +982,10 @@ static int copy_from_psa(mbedtls_svc_key_id_t key_id,
}
key_type = psa_get_key_type(&key_attr);
if (!is_valid_for_pk(key_type)) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
if (public_only) {
key_type = PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(key_type);
}
@@ -972,20 +993,10 @@ static int copy_from_psa(mbedtls_svc_key_id_t key_id,
#if defined(PK_HAVE_KEYS_LARGER_THAN_ECC)
exp_key_size = pk_export_max_size(key_type, key_bits);
if (exp_key_size == 0) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
exp_key = mbedtls_calloc(1, exp_key_size);
if (exp_key == NULL) {
return MBEDTLS_ERR_PK_ALLOC_FAILED;
}
#else
/* In case we're passed non-ECC key (API misuse), return a sensible error
* now. Otherwise we might get BUFFER_TOO_SMALL when exporting below, which
* is unlikely to be helpful to the user as the buffer is internal. */
if (!PSA_KEY_TYPE_IS_ECC(key_type)) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
}
#endif
if (public_only) {