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comparison main.c @ 46:b1c27f1d6289

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bootid hmac challenge prog hmac
author Matt Johnston <matt@ucc.asn.au>
date Sun, 30 Jun 2013 23:34:24 +0800
parents a0f2fcc6d9dd
children 747695bd4e0d
comparison
equal deleted inserted replaced
45:a0f2fcc6d9dd 46:b1c27f1d6289
764 static void 764 static void
765 cmd_bootid(const char *arg) 765 cmd_bootid(const char *arg)
766 { 766 {
767 uint8_t hmac[HMACLEN]; 767 uint8_t hmac[HMACLEN];
768 uint8_t input[CHALLEN+sizeof(boot_id)]; 768 uint8_t input[CHALLEN+sizeof(boot_id)];
769 769
770 if (strlen(arg) != CHALLEN*2)
771 {
772 printf_P(PSTR("Bad challenge\n"));
773 }
774 for (int i = 0, p = 0; i < CHALLEN; i++, p += 2)
775 {
776 input[i] = (from_hex(arg[p]) << 4) | from_hex(arg[p+1]);
777 }
778 memcpy(&input[CHALLEN], boot_id, sizeof(boot_id));
779
780 if (!boot_id_set) 770 if (!boot_id_set)
781 { 771 {
782 _Static_assert(sizeof(boot_id) == HMACLEN, "boot_id size correct"); 772 _Static_assert(sizeof(boot_id) == HMACLEN, "boot_id size correct");
783 get_random(boot_id); 773 get_random(boot_id);
784 boot_id_set = 1; 774 boot_id_set = 1;
785 } 775 }
776
777 if (strlen(arg) != CHALLEN*2)
778 {
779 printf_P(PSTR("Bad challenge\n"));
780 }
781 for (int i = 0, p = 0; i < CHALLEN; i++, p += 2)
782 {
783 input[i] = (from_hex(arg[p]) << 4) | from_hex(arg[p+1]);
784 }
785 memcpy(&input[CHALLEN], boot_id, sizeof(boot_id));
786
786 hmac_sha1(hmac, avr_keys[0], KEYLEN*8, input, sizeof(input)*8); 787 hmac_sha1(hmac, avr_keys[0], KEYLEN*8, input, sizeof(input)*8);
787 printf_P(PSTR("bootid: ")); 788 printf_P(PSTR("bootid: "));
788 printhex(boot_id, sizeof(boot_id), stdout); 789 printhex(boot_id, sizeof(boot_id), stdout);
789 putchar(' '); 790 putchar(' ');
790 printhex(hmac, sizeof(hmac), stdout); 791 printhex(hmac, sizeof(hmac), stdout);
791 putchar('\n'); 792 putchar('\n');
792 } 793 }
793 794
794 void(*bootloader)() __attribute__ ((noreturn)) = (void*)0x7800; 795 void(*bootloader)() __attribute__ ((noreturn)) = (void*)0x7800;
795 796
796 #ifndef PROG_PASSWORD
797 #define PROG_PASSWORD "Y2vvjxO5"
798 #endif
799
800 static void 797 static void
801 cmd_prog(const char* arg) 798 cmd_prog(const char* arg)
802 { 799 {
803 if (!safe_str_eq(arg, PROG_PASSWORD)) 800 uint8_t pw_hmac[HMACLEN];
801 uint8_t good_hmac[HMACLEN];
802
803 const static char prog_hmac[HMACLEN] PROGMEM = {
804 0x73, 0x4d, 0xa6, 0x3f, 0x3b, 0x7e, 0x4d, 0xa4, 0x65, 0xae, 0xea, 0xf9, 0x19, 0xbc, 0x4f, 0x45, 0xa7, 0x8d, 0x5a, 0xce,
805 };
806
807 memcpy_P(good_hmac, prog_hmac, HMACLEN);
808 hmac_sha1(pw_hmac, arg, strlen(arg)*8, "pihelp", strlen("pihelp")*8);
809 if (!safe_mem_eq(pw_hmac, good_hmac, HMACLEN))
804 { 810 {
805 printf_P(PSTR("Bad prog password\n")); 811 printf_P(PSTR("Bad prog password\n"));
806 return; 812 return;
807 } 813 }
808 814