From 6ed9123c24c78a3b01fb95604f5670cc63d3a4e0 Mon Sep 17 00:00:00 2001 From: Michael Scire Date: Thu, 29 Mar 2018 13:14:58 -0600 Subject: [PATCH] Implement NX Key Derivation. --- fusee/src/exocfg.h | 18 +++++ fusee/src/key_derivation.c | 132 +++++++++++++++++++++++++++++++++++++ fusee/src/key_derivation.h | 28 ++++++++ fusee/src/utils.c | 3 +- 4 files changed, 180 insertions(+), 1 deletion(-) create mode 100644 fusee/src/exocfg.h create mode 100644 fusee/src/key_derivation.c create mode 100644 fusee/src/key_derivation.h diff --git a/fusee/src/exocfg.h b/fusee/src/exocfg.h new file mode 100644 index 000000000..07b904b56 --- /dev/null +++ b/fusee/src/exocfg.h @@ -0,0 +1,18 @@ +#ifndef FUSEE_EXOSPHERE_CONFIG_H +#define FUSEE_EXOSPHERE_CONFIG_H + +/* This serves to set configuration for *exosphere itself*, separate from the SecMon Exosphere mimics. */ + +/* "XBC0" */ +#define MAGIC_EXOSPHERE_BOOTCONFIG (0x30434258) + +#define EXOSPHERE_TARGET_FIRMWARE_100 1 +#define EXOSPHERE_TARGET_FIRMWARE_200 2 +#define EXOSPHERE_TARGET_FIRMWARE_300 3 +#define EXOSPHERE_TARGET_FIRMWARE_400 4 +#define EXOSPHERE_TARGET_FIRMWARE_500 5 + +/* TODO: What should this be, for release? */ +#define EXOSPHERE_TARGET_FIRMWARE_DEFAULT_FOR_DEBUG EXOSPHERE_TARGET_FIRMWARE_400 + +#endif \ No newline at end of file diff --git a/fusee/src/key_derivation.c b/fusee/src/key_derivation.c new file mode 100644 index 000000000..27b7a38ed --- /dev/null +++ b/fusee/src/key_derivation.c @@ -0,0 +1,132 @@ +#include "key_derivation.h" +#include "se.h" +#include "exocfg.h" + +static const u8 keyblob_seeds[MASTERKEY_REVISION_MAX][0x10] = +{ + {0xDF, 0x20, 0x6F, 0x59, 0x44, 0x54, 0xEF, 0xDC, 0x70, 0x74, 0x48, 0x3B, 0x0D, 0xED, 0x9F, 0xD3}, /* Keyblob seed 00. */ + {0x0C, 0x25, 0x61, 0x5D, 0x68, 0x4C, 0xEB, 0x42, 0x1C, 0x23, 0x79, 0xEA, 0x82, 0x25, 0x12, 0xAC}, /* Keyblob seed 01. */ + {0x33, 0x76, 0x85, 0xEE, 0x88, 0x4A, 0xAE, 0x0A, 0xC2, 0x8A, 0xFD, 0x7D, 0x63, 0xC0, 0x43, 0x3B}, /* Keyblob seed 02. */ + {0x2D, 0x1F, 0x48, 0x80, 0xED, 0xEC, 0xED, 0x3E, 0x3C, 0xF2, 0x48, 0xB5, 0x65, 0x7D, 0xF7, 0xBE}, /* Keyblob seed 03. */ + {0xBB, 0x5A, 0x01, 0xF9, 0x88, 0xAF, 0xF5, 0xFC, 0x6C, 0xFF, 0x07, 0x9E, 0x13, 0x3C, 0x39, 0x80}, /* Keyblob seed 04. */ +}; + +static const u8 keyblob_mac_seed[0x10] = +{ + 0x59, 0xC7, 0xFB, 0x6F, 0xBE, 0x9B, 0xBE, 0x87, 0x65, 0x6B, 0x15, 0xC0, 0x53, 0x73, 0x36, 0xA5 +}; + +static const uint8_t masterkey_seed[0x10] = +{ + 0xD8, 0xA2, 0x41, 0x0A, 0xC6, 0xC5, 0x90, 0x01, 0xC6, 0x1D, 0x6A, 0x26, 0x7C, 0x51, 0x3F, 0x3C +}; + +static const uint8_t devicekey_seed[0x10] = +{ + 0x4F, 0x02, 0x5F, 0x0E, 0xB6, 0x6D, 0x11, 0x0E, 0xDC, 0x32, 0x7D, 0x41, 0x86, 0xC2, 0xF4, 0x78 +}; + +static const uint8_t devicekey_4x_seed[0x10] = +{ + 0x0C, 0x91, 0x09, 0xDB, 0x93, 0x93, 0x07, 0x81, 0x07, 0x3C, 0xC4, 0x16, 0x22, 0x7C, 0x6C, 0x28 +}; + +static const uint8_t masterkey_4x_seed[0x10] = +{ + 0x2D, 0xC1, 0xF4, 0x8D, 0xF3, 0x5B, 0x69, 0x33, 0x42, 0x10, 0xAC, 0x65, 0xDA, 0x90, 0x46, 0x66 +}; + +void get_tsec_key(void *dst) { + /* TODO: Implement this method. Attempt to read TSEC fw from NAND, or from SD if that fails. */ +} + +void get_keyblob(void *dst, u32 revision) { + if (revision >= 0x20) { + generic_panic(); + } + + /* TODO: Read the appropriate keyblob from eMMC Boot0 partition. */ +} + +bool safe_memcmp(u8 *a, u8 *b, u32 sz) { + u8 different = 0; + for (u32 i = 0; i < sz; i++) { + different |= a[i] ^ b[i]; + } + return different != 0; +} + +/* Derive all Switch keys. */ +void derive_nx_keydata(u32 target_firmware) { + u8 work_buffer[0x10]; + nx_keyblob_t keyblob; + + /* TODO: Set keyslot flags properly in preparation of derivation. */ + set_aes_keyslot_flags(0xE, 0x15); + set_aes_keyslot_flags(0xD, 0x15); + + /* Set TSEC key. */ + get_tsec_key(work_buffer); + set_aes_keyslot(0xD, work_buffer, 0x10); + + + /* Get keyblob, always try to set up the highest possible master key. */ + /* TODO: Should we iterate, trying lower keys on failure? */ + get_keyblob(&keyblob, MASTERKEY_REVISION_500_CURRENT); + + /* Derive both keyblob key 1, and keyblob key latest. */ + se_aes_ecb_decrypt_block(0xD, work_buffer, 0x10, keyblob_seeds[MASTERKEY_REVISION_100_230], 0x10); + decrypt_data_into_keyslot(0xF, 0xE, work_buffer, 0x10); + se_aes_ecb_decrypt_block(0xD, work_buffer, 0x10, keyblob_seeds[MASTERKEY_REVISION_500_CURRENT], 0x10); + decrypt_data_into_keyslot(0xD, 0xE, work_buffer, 0x10); + + /* Clear the SBK. */ + clear_aes_keyslot(0xE); + decrypt_data_into_keyslot(0xB, 0xD, keyblob_mac_seed, 0x10); + + /* Validate keyblob. */ + se_compute_aes_128_cmac(0xB, work_buffer, 0x10, keyblob.mac + sizeof(keyblob.mac), sizeof(keyblob) - sizeof(keyblob.mac)); + if (safe_memcmp(keyblob.mac, work_buffer, 0x10)) { + generic_panic(); + } + + /* Decrypt keyblob. */ + se_aes_ctr_crypt(0xD, keyblob.data, sizeof(keyblob.data), keyblob.data, sizeof(keyblob.data), keyblob.ctr, sizeof(keyblob.ctr)); + + /* Get needed data. */ + set_aes_keyslot(0xC, keyblob.keys[0], 0x10); + /* We don't need the Package1 Key, but for reference: set_aes_keyslot(0xB, keyblob.keys[8], 0x10); */ + + /* Clear keyblob. */ + memset(keyblob.data, 0, sizeof(keyblob.data)); + + /* Derive keys for Exosphere, lock critical keyslots. */ + switch (target_firmware) { + case EXOSPHERE_TARGET_FIRMWARE_100: + case EXOSPHERE_TARGET_FIRMWARE_200: + case EXOSPHERE_TARGET_FIRMWARE_300: + decrypt_data_into_keyslot(0xD, 0xF, devicekey_seed, 0x10); + decrypt_data_into_keyslot(0xC, 0xC, masterkey_seed, 0x10); + set_aes_keyslot_flags(0xC, 0xFF); + set_aes_keyslot_flags(0xD, 0xFF); + break; + case EXOSPHERE_TARGET_FIRMWARE_400: + decrypt_data_into_keyslot(0xD, 0xF, devicekey_4x_seed, 0x10); + decrypt_data_into_keyslot(0xF, 0xF, devicekey_seed, 0x10); + decrypt_data_into_keyslot(0xE, 0xC, masterkey_4x_seed, 0x10); + decrypt_data_into_keyslot(0xC, 0xC, masterkey_seed, 0x10); + set_aes_keyslot_flags(0xC, 0xFF); + set_aes_keyslot_flags(0xF, 0xFF); + break; + case EXOSPHERE_TARGET_FIRMWARE_500: + decrypt_data_into_keyslot(0xA, 0xF, devicekey_4x_seed, 0x10); + decrypt_data_into_keyslot(0xF, 0xF, devicekey_seed, 0x10); + decrypt_data_into_keyslot(0xE, 0xC, masterkey_4x_seed, 0x10); + decrypt_data_into_keyslot(0xC, 0xC, masterkey_seed, 0x10); + set_aes_keyslot_flags(0xC, 0xFF); + set_aes_keyslot_flags(0xF, 0xFF); + break; + default: + generic_panic(); + } +} \ No newline at end of file diff --git a/fusee/src/key_derivation.h b/fusee/src/key_derivation.h new file mode 100644 index 000000000..0e885371f --- /dev/null +++ b/fusee/src/key_derivation.h @@ -0,0 +1,28 @@ +#ifndef FUSEE_KEYDERIVATION_H +#define FUSEE_KEYDERIVATION_H + +#include "hwinit/tsec.h" + +/* TODO: Update to 0x6 on release of new master key. */ +#define MASTERKEY_REVISION_MAX 0x5 + +#define MASTERKEY_REVISION_100_230 0x00 +#define MASTERKEY_REVISION_300 0x01 +#define MASTERKEY_REVISION_301_302 0x02 +#define MASTERKEY_REVISION_400_410 0x03 +#define MASTERKEY_REVISION_500_CURRENT 0x04 + +#define MASTERKEY_NUM_NEW_DEVICE_KEYS (MASTERKEY_REVISION_MAX - MASTERKEY_REVISION_400_410) + +typedef struct { + u8 mac[0x10]; + u8 ctr[0x10]; + union { + u8 data[0x90]; + u8 keys[9][0x10]; + }; +} nx_keyblob_t; + +void derive_nx_keydata(u32 target_firmware); + +#endif \ No newline at end of file diff --git a/fusee/src/utils.c b/fusee/src/utils.c index 37eaac14e..8eb4735ee 100644 --- a/fusee/src/utils.c +++ b/fusee/src/utils.c @@ -17,7 +17,8 @@ __attribute__ ((noreturn)) void panic(uint32_t code) { /* For now, just use NX BOOTLOADER's panic. */ fuse_disable_programming(); APBDEV_PMC_CRYPTO_OP_0 = 1; /* Disable all SE operations. */ - watchdog_reboot(); + /* TODO: watchdog_reboot(); */ + while (1) { } } __attribute__ ((noreturn)) void generic_panic(void) {