lib/mbedtls
1
0
Fork 0
mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2025-08-01 10:06:53 +03:00
Code Activity

Improve the rules on key derivation input types

Browse Source 
Use separate step types for a KDF secret and for the private key in a
key agreement.

Determine which key type is allowed from the step type, independently
of the KDF.

Forbid raw inputs for certain steps. They definitely should be
forbidden for asymmetric keys, which are structured. Also forbid them
for KDF secrets: the secrets are supposed to be keys, even if they're
unstructured.
This commit is contained in:
Gilles Peskine
2019-01-08 10:31:27 +01:00
parent b70a0fd1a5
commit 6cdfdb75a9
3 changed files with 95 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
include/psa/crypto_values.h
View File

@ -1104,6 +1104,15 @@
*
* For example, `PSA_ALG_HKDF(PSA_ALG_SHA256)` is HKDF using HMAC-SHA-256.
*
* This key derivation algorithm uses the following inputs:
* - #PSA_KDF_STEP_SALT is the salt used in the "extract" step.
* It is optional; if omitted, the derivation uses an empty salt.
* - #PSA_KDF_STEP_SECRET is the secret key used in the "extract" step.
* - #PSA_KDF_STEP_INFO is the info string used in the "expand" step.
* You must pass #PSA_KDF_STEP_SALT before #PSA_KDF_STEP_SECRET.
* You may pass #PSA_KDF_STEP_INFO at any time after steup and before
* starting to generate output.
*
* \param hash_alg A hash algorithm (\c PSA_ALG_XXX value such that
* #PSA_ALG_IS_HASH(\p hash_alg) is true).
*
@ -1421,11 +1430,44 @@
* @{
*/
/** A secret input for key derivation.
*
* This must be a key of type #PSA_KEY_TYPE_DERIVE.
*/
#define PSA_KDF_STEP_SECRET ((psa_key_derivation_step_t)0x0101)
/** A label for key derivation.
*
* This must be a direct input.
*/
#define PSA_KDF_STEP_LABEL ((psa_key_derivation_step_t)0x0201)
/** A salt for key derivation.
*
* This must be a direct input.
*/
#define PSA_KDF_STEP_SALT ((psa_key_derivation_step_t)0x0202)
/** An information string for key derivation.
*
* This must be a direct input.
*/
#define PSA_KDF_STEP_INFO ((psa_key_derivation_step_t)0x0203)
#define PSA_KDF_STEP_PEER_KEY ((psa_key_derivation_step_t)0x0301)
/** The private key in a key agreement.
*
* This must be a key pair of the appropriate type for the key agreement
* algorithm.
*/
#define PSA_KDF_STEP_OUR_KEY ((psa_key_derivation_step_t)0x0301)
/** A label for key derivation.
*
* This may be a key pair of the appropriate type for the key agreement
* algorithm, or a direct input which is parsed as a public key in the
* same format as psa_import_key().
*/
#define PSA_KDF_STEP_PEER_KEY ((psa_key_derivation_step_t)0x0302)
/**@}*/