pihelp: main.c comparison

comparison main.c @ 5:87c8d0a11906

make it work

author	Matt Johnston <matt@ucc.asn.au>
date	Wed, 05 Jun 2013 21:29:02 +0800
parents	fd28c7358ce8
children	76f3ed943180

comparison

equal deleted inserted replaced

-:fd28c7358ce8
+:87c8d0a11906
 #include <avr/wdt.h>
 #include <util/atomic.h>
 #include <util/crc16.h>
 #include "hmac-sha1.h"
+#include "aes.h"
 //#include "simple_ds18b20.h"
 //#include "onewire.h"
+LOCKBITS = (LB_MODE_3 & BLB0_MODE_4 & BLB1_MODE_4);
 #define MIN(X,Y) ((X) < (Y) ? (X) : (Y))
 #define MAX(X,Y) ((X) > (Y) ? (X) : (Y))
 // TICK should be 8 or less (8 untested). all timers need
 // to be a multiple.
 #define TICK 1
 #define SLEEP_COMPARE (2000000/64)   // == 31250 exactly
-#define NKEYS 6
+#define NKEYS 10
-#define KEYLEN 20
+#define HMACLEN 20
+#define AESLEN 16
+#define KEYLEN HMACLEN
 #define BAUD 19200
 #define UBRR ((F_CPU)/8/(BAUD)-1)
-// XXX
 #define PORT_PI_BOOT PORTD
 #define DDR_PI_BOOT DDRD
 #define PIN_PI_BOOT PD5
-// XXX
 #define PORT_PI_RESET PORTD
 #define DDR_PI_RESET DDRD
 #define PIN_PI_RESET PD6
 #define PORT_LED PORTD
 #define DDR_LED DDRD
 #define PIN_LED PD7
 CLKPR = _BV(CLKPCE);
 CLKPR = _BV(CLKPS1);
 // enable pullups
 // XXX matt pihelp
-PORTB = 0xff; // XXX change when using SPI
+//PORTB = 0xff; // XXX change when using SPI
-PORTD = 0xff;
+//PORTD = 0xff;
-PORTC = 0xff;
+//PORTC = 0xff;
 // 3.3v power for bluetooth and SD
 DDR_LED |= _BV(PIN_LED);
+#if 0
 // set pullup
 PORTD |= _BV(PD2);
 // INT0 setup
 EICRA = (1<<ISC01); // falling edge - data sheet says it won't work?
 EIMSK = _BV(INT0);
+#endif
 // comparator disable
 ACSR = _BV(ACD);
 // disable adc pin input buffers
 printhex_byte(id[i], stream);
 }
 }
 static int8_t
-parse_key(const char *params, uint8_t *key_index, uint8_t bytes[KEYLEN])
+parse_key(const char *params, uint8_t *key_index, uint8_t *bytes,
+uint8_t bytes_len)
 {
 // "N HEXKEY"
-if (strlen(params) != KEYLEN*2+2) {
+if (strlen(params) != bytes_len*2 + 2) {
 printf_P(PSTR("Wrong length key\n"));
 return -1;
 }
 if (params[1] != ' ')
 {
 printf_P(PSTR("Bad key index %d, max %d\n"), *key_index, NKEYS);
 return -1;
 }
-for (int i = 0, p = 0; i < KEYLEN; i++, p += 2)
+for (int i = 0, p = 0; i < bytes_len; i++, p += 2)
 {
 bytes[i] = (from_hex(params[p+2]) << 4) | from_hex(params[p+3]);
 }
 return 0;
 }
 static void
 cmd_set_avr_key(const char *params)
 {
 uint8_t new_key[KEYLEN];
 uint8_t key_index;
-if (parse_key(params, &key_index, new_key) != 0)
+if (parse_key(params, &key_index, new_key, sizeof(new_key)) != 0)
 {
 return;
 }
 memcpy(avr_keys[key_index], new_key, sizeof(new_key));
 eeprom_write(avr_keys, avr_keys);
 }
 static void
 cmd_hmac(const char *params)
 {
-uint8_t data[KEYLEN];
+uint8_t data[HMACLEN];
 uint8_t key_index;
-if (parse_key(params, &key_index, data) != 0)
+if (parse_key(params, &key_index, data, sizeof(data)) != 0)
 {
 printf_P(PSTR("FAIL: Bad input\n"));
-}
+return;
+}
+if (key_index % 2 == 0)
+{
+printf_P(PSTR("Only hmac with even keys\n"));
+return;
+}
+long_delay(200);
 hmac_sha1_ctx_t ctx;
 hmac_sha1_init(&ctx, avr_keys[key_index], KEYLEN);
-hmac_sha1_lastBlock(&ctx, data, KEYLEN);
+hmac_sha1_lastBlock(&ctx, data, HMACLEN);
 hmac_sha1_final(data, &ctx);
 printf_P(PSTR("HMAC: "));
-printhex(data, KEYLEN, stdout);
+printhex(data, HMACLEN, stdout);
+fputc('\n', stdout);
+}
+static void
+cmd_decrypt(const char *params)
+{
+uint8_t data[HMACLEN+AESLEN];
+uint8_t output[HMACLEN];
+uint8_t key_index;
+if (parse_key(params, &key_index, data, sizeof(data)) != 0)
+{
+printf_P(PSTR("FAIL: Bad input\n"));
+return;
+}
+if (key_index % 2)
+{
+printf_P(PSTR("Only decrypt with odd keys\n"));
+return;
+}
+long_delay(200);
+// check the signature
+hmac_sha1_ctx_t ctx;
+hmac_sha1_init(&ctx, avr_keys[key_index], KEYLEN);
+hmac_sha1_lastBlock(&ctx, &data[HMACLEN], AESLEN);
+hmac_sha1_final(output, &ctx);
+if (memcmp(output, data, HMACLEN) != 0) {
+printf_P(PSTR("FAIL: hmac mismatch\n"));
+}
+uint8_t expkey[AES_EXPKEY_SIZE];
+ExpandKey(avr_keys[key_index], expkey);
+Decrypt(&data[HMACLEN], expkey, output);
+printf_P(PSTR("DECRYPTED: "));
+printhex(output, AESLEN, stdout);
 fputc('\n', stdout);
 }
 static void
 cmd_oneshot_reboot(const char *params)
 }
 else if (strncmp_P(readbuf, PSTR("hmac "), 5) == 0)
 {
 cmd_hmac(&readbuf[5]);
 }
+else if (strncmp_P(readbuf, PSTR("decrypt "), 8) == 0)
+{
+cmd_hmac(&readbuf[8]);
+}
 else if (strcmp_P(readbuf, PSTR("vcc")) == 0)
 {
 cmd_vcc();
 }
 else if (strcmp_P(readbuf, PSTR("reset")) == 0)
 {
 blink();
 _delay_ms(100);
 blink();
 }
 ISR(USART_RX_vect)
 {
 char c = UDR0;
 #ifdef HAVE_UART_ECHO
 blink();
 stdout = &mystdout;
 uart_on();
-printf(PSTR("Started.\n"));
+printf(PSTR("Pi Watchdog\nMatt Johnston [email protected]"));
 set_pi_boot_normal(0);
 load_params();

Mercurial > pihelp

comparison main.c @ 5:87c8d0a11906