Commit 32db7886 authored by Dominik Ermel's avatar Dominik Ermel Committed by Dominik Ermel
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bootutil: Fix X25519 HMAC-SHA512 



The MAC tag of encryption key has been incorrectly using only
32 bytes of HKDF for HMAC-SHA512 keyword.

Signed-off-by: default avatarDominik Ermel <dominik.ermel@nordicsemi.no>
parent 2bc36d0f

boot/bootutil/src/encrypted_psa.c

+5 −1
Original line number Diff line number Diff line
@@ -43,7 +43,11 @@ static const uint8_t ec_pubkey_oid[] = MBEDTLS_OID_ISO_IDENTIFIED_ORG \ 
#define HKDF_AES_KEY_SIZE   (BOOT_ENC_KEY_SIZE)

/* MAC feed */

#define HKDF_MAC_FEED_INDEX (HKDF_AES_KEY_INDEX + HKDF_AES_KEY_SIZE)

#define HKDF_MAC_FEED_SIZE  (32)    /* This is SHA independent */

#if !defined(MCUBOOT_HMAC_SHA512)

#define HKDF_MAC_FEED_SIZE  (32)

#else

#define HKDF_MAC_FEED_SIZE  (64)

#endif

/* Total size */

#define HKDF_SIZE           (HKDF_AES_KEY_SIZE + HKDF_MAC_FEED_SIZE)

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