From 0ef8f1db2e65ee47bf7ae3131e19b93f986fd890 Mon Sep 17 00:00:00 2001 From: Michael Scire Date: Thu, 22 Feb 2018 16:17:12 -0800 Subject: [PATCH] Implement SE secure AES API. --- exosphere/gcm.c | 4 +- exosphere/se.c | 178 ++++++++++++++++++++++++++++++++++++++++- exosphere/se.h | 9 ++- exosphere/sealedkeys.c | 2 +- 4 files changed, 182 insertions(+), 11 deletions(-) diff --git a/exosphere/gcm.c b/exosphere/gcm.c index 20056137e..d89b9ad1d 100644 --- a/exosphere/gcm.c +++ b/exosphere/gcm.c @@ -66,7 +66,7 @@ static void ghash(void *dst, const void *data, size_t data_size, const void *j_b memset(x, 0, 0x10); /* H = aes_ecb_encrypt(zeroes) */ - se_aes_ecb_encrypt_block(KEYSLOT_SWITCH_TEMPKEY, h, 0x10, x, 0x10); + se_aes_128_ecb_encrypt_block(KEYSLOT_SWITCH_TEMPKEY, h, 0x10, x, 0x10); size_t total_size = data_size; @@ -100,7 +100,7 @@ static void ghash(void *dst, const void *data, size_t data_size, const void *j_b /* If final output block, XOR with encrypted J block. */ if (encrypt) { - se_aes_ecb_encrypt_block(KEYSLOT_SWITCH_TEMPKEY, h, 0x10, j_block, 0x10); + se_aes_128_ecb_encrypt_block(KEYSLOT_SWITCH_TEMPKEY, h, 0x10, j_block, 0x10); for (unsigned int i = 0; i < 0x10; i++) { x[i] ^= h[i]; } diff --git a/exosphere/se.c b/exosphere/se.c index 5632f678b..8d9e14835 100644 --- a/exosphere/se.c +++ b/exosphere/se.c @@ -63,6 +63,20 @@ void se_operation_completed(void) { } +void se_check_for_error(void) { + if (g_security_engine == NULL) { + panic(); + } + + if (g_security_engine->INT_STATUS_REG & 0x10000 || g_security_engine->FLAGS_REG & 3 || g_security_engine->ERR_STATUS_REG) { + panic(); + } +} + +void se_trigger_intrrupt(void) { + /* TODO */ +} + void se_verify_flags_cleared(void) { if (g_security_engine == NULL || g_security_engine->FLAGS_REG & 3) { panic(); @@ -168,7 +182,6 @@ void set_rsa_keyslot(unsigned int keyslot, const void *modulus, size_t modulus_ g_se_exp_sizes[keyslot] = exp_size; } - void set_aes_keyslot_iv(unsigned int keyslot, const void *iv, size_t iv_size) { if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX || iv_size > 0x10) { panic(); @@ -180,6 +193,17 @@ void set_aes_keyslot_iv(unsigned int keyslot, const void *iv, size_t iv_size) { } } +void clear_aes_keyslot_iv(unsigned int keyslot) { + if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX) { + panic(); + } + + for (size_t i = 0; i < (0x10 >> 2); i++) { + g_security_engine->AES_KEYTABLE_ADDR = (keyslot << 4) | 8; + g_security_engine->AES_KEYTABLE_DATA = 0; + } +} + void set_se_ctr(const void *ctr) { if (g_security_engine == NULL) { panic(); @@ -362,12 +386,158 @@ void trigger_se_blocking_op(unsigned int op, void *dst, size_t dst_size, const v se_check_for_error(); } -void se_check_for_error(void) { - if (g_security_engine == NULL) { + +/* Secure AES Functionality. */ +void se_perform_aes_block_operation(void *dst, size_t dst_size, const void *src, size_t src_size) { + uint8_t block[0x10]; + + if (g_security_engine == NULL || src_size > sizeof(block) || dst_size > sizeof(block)) { panic(); } - if (g_security_engine->INT_STATUS_REG & 0x10000 || g_security_engine->FLAGS_REG & 3 || g_security_engine->ERR_STATUS_REG) { + /* Load src data into block. */ + memset(block, 0, sizeof(block)); + memcpy(block, src, src_size); + flush_dcache_range(block, block + sizeof(block)); + + /* Trigger AES operation. */ + g_security_engine->BLOCK_COUNT_REG = 0; + trigger_se_blocking_op(1, block, sizeof(block), block, sizeof(block)); + + /* Copy output data into dst. */ + flush_dcache_range(block, block + sizeof(block)); + memcpy(dst, block, dst_size); +} + +void se_aes_ctr_crypt(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size, const void *ctr, size_t ctr_size) { + if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX || ctr_size != 0x10) { panic(); } + + unsigned int num_blocks = src_size >> 4; + + /* Unknown what this write does, but official code writes it for CTR mode. */ + g_security_engine->_0x80C = 1; + g_security_engine->CONFIG_REG = (ALG_AES_ENC | DST_MEMORY); + g_security_engine->CRYPTO_REG = (keyslot << 24) | 0x91E; + set_se_ctr(ctr, ctr_size); + + /* Handle any aligned blocks. */ + size_t aligned_size = (size_t)num_blocks << 4; + if (aligned_size) { + g_security_engine->BLOCK_COUNT_REG = num_blocks - 1; + trigger_se_blocking_op(1, dst, dst_size, src, aligned_size); + } + + /* Handle final, unaligned block. */ + if (aligned_size < dst_size && aligned_size < src_size) { + size_t last_block_size = dst_size - aligned_size; + if (src_size < dst_size) { + last_block_size = src_size - aligned_size; + } + se_perform_aes_block_operation(dst + aligned_size, last_block_size, src + aligned_size, src - aligned_size); + } } + +void se_aes_ecb_encrypt_block(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size, unsigned int config_high) { + if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX || dst_size != 0x10 || src_size != 0x10) { + panic(); + } + + /* Set configuration high (256-bit vs 128-bit) based on parameter. */ + g_security_engine->CONFIG_REG = (ALG_AES_ENC | DST_MEMORY) | (config_high << 16); + g_security_engine->CRYPTO_REG = keyslot << 24; + se_perform_aes_block_operation(1, dst, 0x10, src, 0x10); + +} + +void se_aes_128_ecb_encrypt_block(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size) { + se_aes_ecb_encrypt_block(keyslot, dst, dst_size, src, src_size, 0); +} + +void se_aes_256_ecb_encrypt_block(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size) { + se_aes_ecb_encrypt_block(keyslot, dst, dst_size, src, src_size, 0x202); +} + + +void se_aes_ecb_decrypt_block(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size) { + if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX || dst_size != 0x10 || src_size != 0x10) { + panic(); + } + + g_security_engine->CONFIG_REG = (ALG_AES_DEC | DST_MEMORY); + g_security_engine->CRYPTO_REG = keyslot << 24; + se_perform_aes_block_operation(1, dst, 0x10, src, 0x10); +} + +void shift_left_xor_rb(uint8_t *key) { + uint8_t prev_high_bit = 0; + for (unsigned int i = 0xF; i >= 0; i--) { + uint8_t cur_byte = key[i]; + key[i] = (cur_byte << 1) | (prev_high_bit); + prev_high_bit = cur_byte >> 7; + } + if (prev_high_bit) { + key[0xF] ^= 0x87; + } +} + +void se_compute_aes_cmac(unsigned int keyslot, void *cmac, size_t cmac_size, const void *data, size_t data_size, unsigned int config_high) { + if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX) { + panic(); + } + + /* Generate the derived key, to be XOR'd with final output block. */ + uint8_t derived_key[0x10]; + memset(derived_key, 0, sizeof(derived_key)); + se_aes_128_ecb_encrypt_block(keyslot, derived_key, sizeof(derived_key), derived_key, sizeof(derived_key)); + shift_left_xor_rb(derived_key); + if (data_size & 0xF) { + shift_left_xor_rb(derived_key); + } + + g_security_engine->CONFIG_REG = (ALG_AES_ENC | DST_HASHREG) | (config_high << 16); + g_security_engine->CRYPTO_REG = (keyslot << 24) | (0x145); + clear_aes_keyslot_iv(keyslot); + + unsigned int num_blocks = (data_size + 0xF) >> 4; + /* Handle aligned blocks. */ + if (num_blocks > 1) { + g_security_engine->BLOCK_COUNT_REG = num_blocks - 2; + trigger_se_blocking_op(1, NULL, 0, data, data_size); + g_security_engine->CRYPTO_REG |= 0x80; + } + + /* Create final block. */ + uint8_t last_block[0x10]; + memset(last_block, 0, sizeof(last_block)); + if (data_size & 0xF) { + + memcpy(last_block, data + (data_size & ~0xF), data_size & 0xF); + last_block[data_size & 0xF] = 0x80; /* Last block = data || 100...0 */ + } else if (data_size >= 0x10) { + memcpy(last_block, data + data_size - 0x10, 0x10); + } + + for (unsigned int i = 0; i < 0x10; i++) { + last_block[i] ^= derived_key[i]; + } + + /* Perform last operation. */ + flush_dcache_range(last_block, last_block + sizeof(last_block)); + trigger_se_blocking_op(1, NULL, 0, last_block, sizeof(last_block)); + + /* Copy output CMAC. */ + for (unsigned int i = 0; i < (cmac_size >> 2); i++) { + ((uint32_t *)cmac)[i] = read32le(g_security_engine->HASH_OUTPUT, i << 2); + } +} + +void se_compute_aes_128_cmac(unsigned int keyslot, void *cmac, size_t cmac_size, const void *data, size_t data_size) { + se_compute_aes_cmac(keyslot, cmac, cmac_size, data, data_size, 0); +} +void se_compute_aes_256_cmac(unsigned int keyslot, void *cmac, size_t cmac_size, const void *data, size_t data_size) { + se_compute_aes_cmac(keyslot, cmac, cmac_size, data, data_size, 0x202); +} + + diff --git a/exosphere/se.h b/exosphere/se.h index d8eafe424..9fb67c44b 100644 --- a/exosphere/se.h +++ b/exosphere/se.h @@ -64,7 +64,7 @@ typedef struct security_engine { unsigned int OUT_LL_ADDR_REG; unsigned int _0x28; unsigned int _0x2C; - unsigned char cmacOutput[0x10]; + unsigned char HASH_OUTPUT[0x10]; unsigned char reserved0x40[0x240]; unsigned int AES_KEY_READ_DISABLE_REG; unsigned int AES_KEYSLOT_FLAGS[0x10]; @@ -152,10 +152,11 @@ void se_aes_cbc_encrypt_insecure(unsigned int keyslot, uint32_t out_ll_paddr, ui void se_aes_cbc_decrypt_insecure(unsigned int keyslot, uint32_t out_ll_paddr, uint32_t in_ll_paddr, size_t size, const void *iv, unsigned int (*callback)(void)); /* Secure AES API */ -void se_compute_aes_128_cmac(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size); -void se_compute_aes_256_cmac(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size); +void se_compute_aes_128_cmac(unsigned int keyslot, void *cmac, size_t cmac_size, const void *data, size_t data_size); +void se_compute_aes_256_cmac(unsigned int keyslot, void *cmac, size_t cmac_size, const void *data, size_t data_size); +void se_aes_128_ecb_encrypt_block(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size); +void se_aes_256_ecb_encrypt_block(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size); void se_aes_ctr_crypt(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size, const void *ctr, size_t ctr_size); -void se_aes_ecb_encrypt_block(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size); void se_aes_ecb_decrypt_block(unsigned int keyslot, void *dst, size_t dst_size, const void *src, size_t src_size); /* Hash API */ diff --git a/exosphere/sealedkeys.c b/exosphere/sealedkeys.c index 93d9c3c60..cfcf890e7 100644 --- a/exosphere/sealedkeys.c +++ b/exosphere/sealedkeys.c @@ -18,7 +18,7 @@ const uint8_t g_seal_key_sources[CRYPTOUSECASE_MAX][0x10] = { void seal_key_internal(void *dst, const void *src, const uint8_t *seal_key_source) { decrypt_data_into_keyslot(KEYSLOT_SWITCH_TEMPKEY, KEYSLOT_SWITCH_SESSIONKEY, seal_key_source, 0x10); - se_aes_ecb_encrypt_block(KEYSLOT_SWITCH_TEMPKEY, dst, 0x10, src, 0x10); + se_aes_128_ecb_encrypt_block(KEYSLOT_SWITCH_TEMPKEY, dst, 0x10, src, 0x10); } void unseal_key_internal(unsigned int keyslot, const void *src, const uint8_t *seal_key_source) {