diff options
| -rw-r--r-- | controller/fw/Makefile | 20 | ||||
| -rw-r--r-- | controller/fw/src/crypto.c | 48 | ||||
| -rw-r--r-- | controller/fw/src/crypto.h | 33 | ||||
| -rw-r--r-- | controller/fw/src/dsss_demod.c | 2 | ||||
| -rw-r--r-- | controller/fw/src/dsss_demod.h | 2 | ||||
| -rw-r--r-- | controller/fw/tools/crypto_test.c | 46 | ||||
| -rw-r--r-- | controller/fw/tools/dsss_demod_test.c | 2 | ||||
| -rw-r--r-- | controller/fw/tools/presig_gen.py | 143 | ||||
| -rw-r--r-- | lab-windows/cryptography_experiments.ipynb | 2 |
9 files changed, 292 insertions, 6 deletions
diff --git a/controller/fw/Makefile b/controller/fw/Makefile index a7d690a..c678963 100644 --- a/controller/fw/Makefile +++ b/controller/fw/Makefile @@ -60,6 +60,10 @@ DSSS_FILTER_ORDER ?= 12 PAYLOAD_DATA_BIT ?= 64 TRANSMISSION_SYMBOLS ?= 32 +PRESIG_STORE_SIZE ?= 3 + +PRESIG_KEYFILE ?= presig_test_key.private +PRESIG_DBFILE ?= presig_test_db.sqlite3 CC := $(PREFIX)gcc CXX := $(PREFIX)g++ @@ -90,7 +94,7 @@ MUSL_DIR_ABS := $(abspath $(MUSL_DIR)) COMMON_CFLAGS += -I$(OPENCM3_DIR_ABS)/include -Imspdebug/util -Imspdebug/drivers -Ilevmarq COMMON_CFLAGS += -I$(CMSIS_DIR_ABS)/CMSIS/DSP/Include -I$(CMSIS_DIR_ABS)/CMSIS/Core/Include CFLAGS += -I$(abspath musl_include_shims) -COMMON_CFLAGS += -I$(BUILDDIR) -Isrc +COMMON_CFLAGS += -I$(BUILDDIR) -Isrc -Itinyaes COMMON_CFLAGS += -Os -std=gnu11 -g -DSTM32F4 CFLAGS += -mthumb -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16 @@ -107,6 +111,7 @@ COMMON_CFLAGS += -DDSSS_WAVELET_WIDTH=$(DSSS_WAVELET_WIDTH) COMMON_CFLAGS += -DDSSS_WAVELET_LUT_SIZE=$(DSSS_WAVELET_LUT_SIZE) COMMON_CFLAGS += -DPAYLOAD_DATA_BIT=$(PAYLOAD_DATA_BIT) COMMON_CFLAGS += -DTRANSMISSION_SYMBOLS=$(TRANSMISSION_SYMBOLS) +COMMON_CFLAGS += -DPRESIG_STORE_SIZE=$(PRESIG_STORE_SIZE) # for musl CFLAGS += -Dhidden= @@ -154,6 +159,14 @@ $(BUILDDIR)/generated/dsss_cwt_wavelet.c: | $(BUILDDIR)/generated $(BUILDDIR)/generated/dsss_butter_filter.h: | $(BUILDDIR)/generated $(PYTHON3) tools/butter_filter_gen.py -m dsss_filter $(DSSS_FILTER_FC) $(FMEAS_SAMPLING_RATE) $(DSSS_FILTER_ORDER) > $@ +.PRECIOUS: $(BUILDDIR)/generated/crypto_presig_data.c +$(BUILDDIR)/generated/crypto_presig_data.c: $(PRESIG_KEYFILE) tools/presig_gen.py | $(BUILDDIR)/generated + $(PYTHON3) tools/presig_gen.py $(PRESIG_KEYFILE) $(PRESIG_DBFILE) > $@ + +.PRECIOUS: $(PRESIG_KEYFILE) +$(PRESIG_KEYFILE): + $(PYTHON3) tools/presig_gen.py -g $@ + $(BUILDDIR)/generated: ; mkdir -p $@ OBJS := $(addprefix $(BUILDDIR)/,$(C_SOURCES:.c=.o) $(CXX_SOURCES:.cpp=.o)) @@ -180,6 +193,11 @@ $(BUILDDIR)/tools/dsss_demod_test: tools/dsss_demod_test.c src/dsss_demod.c $(BU mkdir -p $(@D) $(HOST_CC) $(COMMON_CFLAGS) $(SIM_CFLAGS) -o $@ $^ +tools: $(BUILDDIR)/tools/crypto_test +$(BUILDDIR)/tools/crypto_test: tools/crypto_test.c src/crypto.c tinyaes/aes.c $(BUILDDIR)/generated/crypto_presig_data.c + mkdir -p $(@D) + $(HOST_CC) $(COMMON_CFLAGS) $(SIM_CFLAGS) -lsodium -o $@ $^ + $(BUILDDIR)/src/%.o: src/%.c mkdir -p $(@D) $(CC) $(COMMON_CFLAGS) $(CFLAGS) $(INT_CFLAGS) -o $@ -c $< diff --git a/controller/fw/src/crypto.c b/controller/fw/src/crypto.c new file mode 100644 index 0000000..73ad783 --- /dev/null +++ b/controller/fw/src/crypto.c @@ -0,0 +1,48 @@ + +#include <unistd.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> + +#include <aes.h> + +#include "crypto.h" +#include "simulation.h" + +void debug_hexdump(const char *name, uint8_t *buf, size_t len); +void debug_hexdump(const char *name, uint8_t *buf, size_t len) { + DEBUG_PRINTN("%20s: ", name); + for (size_t i=0; i<len;) { + for (size_t j=0; j<8 && i<len; i++, j++) + DEBUG_PRINTN("%02x ", buf[i]); + DEBUG_PRINTN(" "); + } + DEBUG_PRINTN("\n"); +} + +int oob_message_received(uint8_t msg[static OOB_TRIGGER_LEN]) { + struct AES_ctx ctx; + uint8_t buf[crypto_sign_BYTES]; + + for (size_t serial=0; serial<PRESIG_STORE_SIZE; serial++) { + for (size_t dom=0; dom<_TRIGGER_DOMAIN_COUNT; dom++) { + + DEBUG_PRINT("Trying domain %zd serial %zd", dom, serial); + debug_hexdump("oob_presig_iv", oob_presig_iv, sizeof(oob_presig_iv)); + + memcpy(buf, presig_store[dom][serial], crypto_sign_BYTES); + debug_hexdump("presig", buf, sizeof(buf)); + AES_init_ctx_iv(&ctx, msg, oob_presig_iv); + AES_CBC_decrypt_buffer(&ctx, buf, crypto_sign_BYTES); + debug_hexdump("decrypted", buf, sizeof(buf)); + + if (!crypto_sign_verify_detached(buf, presig_messages[dom][serial], PRESIG_MSG_LEN, oob_trigger_pubkey)) { + oob_trigger_activated(dom, presig_first_serial + serial); + return 1; + } + DEBUG_PRINTN("\n"); + } + } + + return 0; +} diff --git a/controller/fw/src/crypto.h b/controller/fw/src/crypto.h new file mode 100644 index 0000000..61a0da8 --- /dev/null +++ b/controller/fw/src/crypto.h @@ -0,0 +1,33 @@ +#ifndef __CRYPTO_H__ +#define __CRYPTO_H__ + +#include <stdint.h> + +#include <sodium.h> + + +#define OOB_TRIGGER_LEN 16 +#define PRESIG_MSG_LEN 16 + + +enum trigger_domain { + TRIGGER_DOMAIN_ALL, + TRIGGER_DOMAIN_VENDOR, + TRIGGER_DOMAIN_SERIES, + TRIGGER_DOMAIN_COUNTRY, + TRIGGER_DOMAIN_REGION, + _TRIGGER_DOMAIN_COUNT +}; + +extern uint8_t presig_store[_TRIGGER_DOMAIN_COUNT][PRESIG_STORE_SIZE][crypto_sign_BYTES]; +extern uint8_t oob_trigger_pubkey[crypto_sign_PUBLICKEYBYTES]; +extern uint8_t presig_messages[_TRIGGER_DOMAIN_COUNT][PRESIG_STORE_SIZE][PRESIG_MSG_LEN]; +extern uint8_t oob_presig_iv[16]; +extern int presig_first_serial; + + +extern void oob_trigger_activated(enum trigger_domain domain, int serial); + +int oob_message_received(uint8_t msg[static OOB_TRIGGER_LEN]); + +#endif /* __CRYPTO_H__ */ diff --git a/controller/fw/src/dsss_demod.c b/controller/fw/src/dsss_demod.c index 97cc039..c5a2070 100644 --- a/controller/fw/src/dsss_demod.c +++ b/controller/fw/src/dsss_demod.c @@ -248,7 +248,6 @@ void group_received(struct dsss_demod_state *st) { /* If we found empty entries, replace one by a new decoding starting at this group */ if (empty_idx >= 0) { - DEBUG_PRINT("Writing to %zd", empty_idx); assert(0 <= empty_idx && empty_idx < DSSS_MATCHER_CACHE_SIZE); st->matcher_cache[empty_idx].last_phase = group_phase; st->matcher_cache[empty_idx].candidate_score = base_score; @@ -261,7 +260,6 @@ void group_received(struct dsss_demod_state *st) { /* If the weakest decoding in cache is weaker than a new decoding starting here, replace it */ } else if (min_score < base_score && min_idx >= 0) { - DEBUG_PRINT("Writing to %zd", min_idx); assert(0 <= min_idx && min_idx < DSSS_MATCHER_CACHE_SIZE); st->matcher_cache[min_idx].last_phase = group_phase; st->matcher_cache[min_idx].candidate_score = base_score; diff --git a/controller/fw/src/dsss_demod.h b/controller/fw/src/dsss_demod.h index e7e5cf9..98cf590 100644 --- a/controller/fw/src/dsss_demod.h +++ b/controller/fw/src/dsss_demod.h @@ -63,7 +63,7 @@ struct dsss_demod_state { }; -extern void handle_dsss_received(uint8_t data[TRANSMISSION_SYMBOLS]); +extern void handle_dsss_received(uint8_t data[static TRANSMISSION_SYMBOLS]); void dsss_demod_init(struct dsss_demod_state *st); void dsss_demod_step(struct dsss_demod_state *st, float new_value, uint64_t ts); diff --git a/controller/fw/tools/crypto_test.c b/controller/fw/tools/crypto_test.c new file mode 100644 index 0000000..8552117 --- /dev/null +++ b/controller/fw/tools/crypto_test.c @@ -0,0 +1,46 @@ + +#include <stdint.h> +#include <math.h> +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <stdlib.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/fcntl.h> + +#include "crypto.h" + +void oob_trigger_activated(enum trigger_domain domain, int serial) { + printf("oob_trigger_activated(%d, %d)\n", domain, serial); + fflush(stdout); +} + +void print_usage() { + fprintf(stderr, "Usage: crypto_test [auth_key_hex]\n"); +} + +int main(int argc, char **argv) { + if (argc != 2) { + fprintf(stderr, "Error: Invalid arguments.\n"); + print_usage(); + return 1; + } + + uint8_t auth_key[16]; + + for (size_t i=0; argv[1][i+0] != '\0' && argv[1][i+1] != '\0'; i+= 2) { + char buf[3] = { argv[1][i+0], argv[1][i+1], 0}; + char *endptr; + auth_key[i/2] = strtoul(buf, &endptr, 16); + if (!endptr || *endptr != '\0') { + fprintf(stderr, "Invalid authkey\n"); + return 1; + } + } + + printf("rc=%d\n", oob_message_received(auth_key)); + + return 0; +} diff --git a/controller/fw/tools/dsss_demod_test.c b/controller/fw/tools/dsss_demod_test.c index d09ce87..64fd889 100644 --- a/controller/fw/tools/dsss_demod_test.c +++ b/controller/fw/tools/dsss_demod_test.c @@ -12,7 +12,7 @@ #include "dsss_demod.h" -void handle_dsss_received(uint8_t data[TRANSMISSION_SYMBOLS]) { +void handle_dsss_received(uint8_t data[static TRANSMISSION_SYMBOLS]) { printf("data sequence received: [ "); for (size_t i=0; i<TRANSMISSION_SYMBOLS; i++) { printf("%+3d", ((data[i]&1) ? 1 : -1) * (data[i]>>1)); diff --git a/controller/fw/tools/presig_gen.py b/controller/fw/tools/presig_gen.py new file mode 100644 index 0000000..2d97391 --- /dev/null +++ b/controller/fw/tools/presig_gen.py @@ -0,0 +1,143 @@ +#!/usr/bin/env python3 + +import os +import sys +import textwrap +import uuid +import hashlib +import binascii +import sqlite3 +import time + +import nacl.signing +import nacl.encoding + +from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes +from cryptography.hazmat.backends import default_backend + + +PRESIG_VERSION = '000.001' + +def format_hex(data, indent=4, wrap=True): + indent = ' '*indent + par = ', '.join(f'0x{b:02x}' for b in data) + par = textwrap.fill(par, width=120, + initial_indent=indent, subsequent_indent=indent, + replace_whitespace=False, drop_whitespace=False) + if wrap: + return f'{{\n{par}\n}}' + return par + +def domain_string(domain_name, value, serial): + return f'smart reset domain string v{PRESIG_VERSION}: domain:{domain_name}={value}@{serial}' + +if __name__ == '__main__': + import argparse + parser = argparse.ArgumentParser() + parser.add_argument('keyfile', help='Key file to use') + parser.add_argument('presig_db', nargs='?', help='sqlite3 dbfile for generated presig authorization keys') + parser.add_argument('-g', '--generate', action='store_true', help='Generate signing keypair') + parser.add_argument('-v', '--vendor', type=str, default='Darthenschmidt Cyberei und Verschleierungstechnik GmbH', help='Vendor name for vendor domain') + parser.add_argument('-s', '--series', type=str, default='Frobnicator v0.23.7', help='Series identifier for series domain') + parser.add_argument('-r', '--region', type=str, default='Neuland', help='Region name for region domain') + parser.add_argument('-c', '--country', type=str, default='Germany', help='Country name for country domain') + parser.add_argument('-p', '--start-serial', type=int, default=0, help='First presig serial number to use') + parser.add_argument('-n', '--presig-count', type=int, default=3, help='Number of presigs to generate') + parser.add_argument('-i', '--iv', type=str, default='safety reset oob presig iv', help='IV for presig generation') + args = parser.parse_args() + + if args.generate: + if os.path.exists(args.keyfile): + print("Error: keyfile already exists. We won't overwrite it. Instead please remove it manually.", + file=sys.stderr) + sys.exit(1) + signing_key = nacl.signing.SigningKey.generate() + with open(args.keyfile, 'wb') as f: + f.write(signing_key.encode(encoder=nacl.encoding.Base64Encoder)) + f.write(b'\n') + sys.exit(0) + + with open(args.keyfile, 'r') as f: + signing_key = nacl.signing.SigningKey(f.read().strip(), encoder=nacl.encoding.Base64Encoder) + pubkey_bytes = signing_key.verify_key.encode(encoder=nacl.encoding.RawEncoder) + pubkey_hash = hashlib.sha512(pubkey_bytes).digest()[:16] + + if not args.presig_db: + print('The presig_db parameter is required.', file=sys.stderr) + sys.exit(1) + + db = sqlite3.connect(args.presig_db) + db.execute('CREATE TABLE IF NOT EXISTS presig_authkey (timestamp, pubkey_hash, bundle_id, presig_ver, domain, value, serial, authkey)') + + bundle_id = uuid.uuid4().bytes + + print('#include <stdint.h>') + print('#include <assert.h>') + print() + print('#include "crypto.h"') + print() + + print(f'/* bundle id {binascii.hexlify(bundle_id).decode()} */') + print(f'uint8_t presig_bundle_id[16] = {format_hex(bundle_id)};') + print(f'int presig_first_serial = {args.start_serial};') + print() + + print(f'uint8_t oob_trigger_pubkey[crypto_sign_PUBLICKEYBYTES] = {format_hex(pubkey_bytes)};') + print() + + print('uint8_t presig_messages[_TRIGGER_DOMAIN_COUNT][PRESIG_STORE_SIZE][PRESIG_MSG_LEN] = {') + device_domains = { + 'all': 'all', + 'country': args.country, + 'region': args.region, + 'vendor': args.vendor, + 'series': args.series + } + presigs = { dom: [] for dom in device_domains } + for dom, val in device_domains.items(): + print(' {') + for i in range(args.presig_count): + serial = args.start_serial + i + ds = domain_string(dom, val, serial) + ds_hash = hashlib.sha512(ds.encode()).digest()[:16] + presigs[dom].append((ds_hash, val, serial)) + print(f' {{ /* "{ds}" */') + print(format_hex(ds_hash, indent=8, wrap=False)) + print(f' }},') + print(' },') + print('};') + print() + + presig_iv = hashlib.sha512(args.iv.encode()).digest()[:16] + print(f'uint8_t oob_presig_iv[16] = {{ /* sha512("{args.iv}")[:16] */') + print(format_hex(presig_iv, wrap=False)) + print(f'}};') + print() + + + print('uint8_t presig_store[_TRIGGER_DOMAIN_COUNT][PRESIG_STORE_SIZE][crypto_sign_BYTES] = {') + for dom, hashes in presigs.items(): + print(f' {{ /* domain {dom} */') + + for ds_hash, val, serial in hashes: + authkey = os.urandom(16) + cipher = Cipher(algorithms.AES(authkey), modes.CTR(presig_iv), backend=default_backend()) + enc = cipher.encryptor() + ciphertext = enc.update(ds_hash) + assert len(enc.finalize()) == 0 + + with db: + db.execute('INSERT INTO presig_authkey VALUES (?, ?, ?, ?, ?, ?, ?, ?)', + (int(time.time()*1000), pubkey_hash, binascii.hexlify(bundle_id).decode(), PRESIG_VERSION, dom, + print(format_hex(ciphertext, indent=8, wrap=False)) + print(f' }},') + + print(f' }},') + print(f'}};') + + print() + print('static inline void __hack_asserts_only(void) {') + print(f' static_assert(_TRIGGER_DOMAIN_COUNT == {len(presigs)});') + print(f' static_assert(PRESIG_STORE_SIZE == {args.presig_count});') + print('}') + print() diff --git a/lab-windows/cryptography_experiments.ipynb b/lab-windows/cryptography_experiments.ipynb index abf571e..c7c046a 100644 --- a/lab-windows/cryptography_experiments.ipynb +++ b/lab-windows/cryptography_experiments.ipynb @@ -122,7 +122,7 @@ "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", - "version": "3.8.1" + "version": "3.8.2" } }, "nbformat": 4, |