diff --git a/exosphere/src/gcm.c b/exosphere/src/gcm.c index bf2217f7d..239093c34 100644 --- a/exosphere/src/gcm.c +++ b/exosphere/src/gcm.c @@ -13,7 +13,7 @@ * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ - + #include #include @@ -83,7 +83,7 @@ static void ghash(void *dst, const void *data, size_t data_size, const void *j_b /* H = aes_ecb_encrypt(zeroes) */ se_aes_128_ecb_encrypt_block(KEYSLOT_SWITCH_TEMPKEY, h, 0x10, x, 0x10); - + size_t total_size = data_size; while (data_size >= 0x10) { @@ -103,7 +103,7 @@ static void ghash(void *dst, const void *data, size_t data_size, const void *j_b if (data_size & 0xF) { gf128_mul(x, x, h); } - + uint64_t xor_size = total_size << 3; xor_size = __builtin_bswap64(xor_size); @@ -113,9 +113,9 @@ static void ghash(void *dst, const void *data, size_t data_size, const void *j_b } else { p_x[1] ^= xor_size; } - + gf128_mul(x, x, h); - + /* If final output block, XOR with encrypted J block. */ if (encrypt) { se_aes_128_ecb_encrypt_block(KEYSLOT_SWITCH_TEMPKEY, h, 0x10, j_block, 0x10); @@ -140,22 +140,22 @@ size_t gcm_decrypt_key(void *dst, size_t dst_size, const void *src, size_t src_s generic_panic(); } } - + uint8_t intermediate_buf[0x400] = {0}; - + /* Unwrap the key */ unseal_key(KEYSLOT_SWITCH_TEMPKEY, sealed_kek, kek_size, usecase); decrypt_data_into_keyslot(KEYSLOT_SWITCH_TEMPKEY, KEYSLOT_SWITCH_TEMPKEY, wrapped_key, key_size); - + /* Decrypt the GCM keypair, AES-CTR with CTR = blob[:0x10]. */ se_aes_ctr_crypt(KEYSLOT_SWITCH_TEMPKEY, intermediate_buf, dst_size, src + 0x10, src_size - 0x10, src, 0x10); - + if (!is_personalized) { /* Devkit non-personalized keys have no further authentication. */ memcpy(dst, intermediate_buf, src_size - 0x10); memset(intermediate_buf, 0, sizeof(intermediate_buf)); return src_size - 0x10; - } + } /* J = GHASH(CTR); */ uint8_t j_block[0x10]; @@ -166,7 +166,7 @@ size_t gcm_decrypt_key(void *dst, size_t dst_size, const void *src, size_t src_s /* It is supposed to be over the ciphertext. */ uint8_t calc_mac[0x10]; ghash(calc_mac, intermediate_buf, src_size - 0x20, j_block, true); - + /* Const-time memcmp. */ const uint8_t *src_bytes = src; int different = 0; @@ -184,7 +184,7 @@ size_t gcm_decrypt_key(void *dst, size_t dst_size, const void *src, size_t src_s if (out_deviceid_high != NULL) { *out_deviceid_high = intermediate_buf[src_size - 0x28]; } - + memcpy(dst, intermediate_buf, src_size - 0x30); memset(intermediate_buf, 0, sizeof(intermediate_buf)); return src_size - 0x30; @@ -205,10 +205,12 @@ void gcm_encrypt_key(void *dst, size_t dst_size, const void *src, size_t src_siz se_generate_random(KEYSLOT_SWITCH_RNGKEY, intermediate_buf, 0x10); flush_dcache_range(intermediate_buf, intermediate_buf + 0x10); + /* Copy in the src. */ + memcpy(intermediate_buf + 0x10, src, src_size); + /* Write Device ID. */ write64be(intermediate_buf, src_size + 0x18, fuse_get_device_id() | (deviceid_high << 56)); - /* J = GHASH(CTR); */ uint8_t j_block[0x10]; ghash(j_block, intermediate_buf, 0x10, NULL, false);