From 435e96e1b31b1352e0653081fe620532c3ad6489 Mon Sep 17 00:00:00 2001
From: Pavol Rusnak <stick@gk2.sk>
Date: Sat, 1 Apr 2017 02:32:05 +0200
Subject: [PATCH] build: refactor binctl and firmware/loader image stuff

---
 Makefile.loader                 |   1 +
 docs/bootloader.md              |  12 ++--
 micropython/bootloader/crypto.c |  24 ++++---
 micropython/bootloader/main.c   |  42 +++++------
 micropython/firmware/header.S   |  28 ++++----
 micropython/firmware/memory.ld  |   6 +-
 micropython/loader/crypto.c     | 105 +++++++++++++++++++++++++++
 micropython/loader/crypto.h     |  11 +++
 micropython/loader/header.S     |  28 ++++----
 micropython/loader/main.c       |  33 +++++++--
 micropython/loader/memory.ld    |   9 ++-
 tools/binctl                    | 122 +++++++++++---------------------
 12 files changed, 265 insertions(+), 156 deletions(-)
 create mode 100644 micropython/loader/crypto.c
 create mode 100644 micropython/loader/crypto.h

diff --git a/Makefile.loader b/Makefile.loader
index f67a6feff..ceb9a2a90 100644
--- a/Makefile.loader
+++ b/Makefile.loader
@@ -56,6 +56,7 @@ OBJ_HAL += $(addprefix $(BUILD_MP)/,\
 
 # OBJ micropython/
 OBJ_FW += $(addprefix $(BUILD_FW)/, \
+	loader/crypto.o \
 	loader/header.o \
 	loader/main.o \
 	extmod/modtrezorui/display.o \
diff --git a/docs/bootloader.md b/docs/bootloader.md
index 4aa40df54..001bf0737 100644
--- a/docs/bootloader.md
+++ b/docs/bootloader.md
@@ -48,8 +48,8 @@ Total length of loader header is always 512 bytes.
 | 0x0012 | 1      | vpatch | version (patch) |
 | 0x0013 | 1      | vbuild | version (build) |
 | 0x0014 | 427    | reserved | not used yet (zeroed) |
-| 0x01BF | 1      | sigidx | SatoshiLabs signature indexes (bitmap) |
-| 0x01C0 | 64     | sig | SatoshiLabs signature |
+| 0x01BF | 1      | sigmask | SatoshiLabs signature indexes (bitmap) |
+| 0x01C0 | 64     | sig | SatoshiLabs aggregated signature |
 
 ## Firmware Format
 
@@ -79,8 +79,8 @@ Total length of vendor header is 84 + 32 * (number of pubkeys) + (length of vend
 | ?      | ?      | vstr | vendor string |
 | ?      | 2      | vimg_len | vendor image length |
 | ?      | ?      | vimg | vendor image (in [TOIf format](toif.md)) |
-| ?      | 1      | sigidx | SatoshiLabs signature indexes (bitmap) |
-| ?      | 64     | sig | SatoshiLabs signature |
+| ?      | 1      | sigmask | SatoshiLabs signature indexes (bitmap) |
+| ?      | 64     | sig | SatoshiLabs aggregated signature |
 
 ### Firmware Header
 
@@ -97,8 +97,8 @@ Total length of firmware header is always 512 bytes.
 | 0x0012 | 1      | vpatch | version (patch) |
 | 0x0013 | 1      | vbuild | version (build) |
 | 0x0014 | 427    | reserved | not used yet (zeroed) |
-| 0x01BF | 1      | sigidx | vendor signature indexes (bitmap) |
-| 0x01C0 | 64     | sig | vendor signature |
+| 0x01BF | 1      | sigmask | vendor signature indexes (bitmap) |
+| 0x01C0 | 64     | sig | vendor aggregated signature |
 
 ## Various ideas
 
diff --git a/micropython/bootloader/crypto.c b/micropython/bootloader/crypto.c
index 58358b95b..fe8339c38 100644
--- a/micropython/bootloader/crypto.c
+++ b/micropython/bootloader/crypto.c
@@ -3,9 +3,10 @@
 #include "blake2s.h"
 #include "ed25519-donna/ed25519.h"
 
+#include "common.h"
 #include "crypto.h"
 
-bool parse_header(const uint8_t *data, uint32_t *codelen, uint8_t *sigidx, uint8_t *sig)
+bool parse_header(const uint8_t *data, uint32_t *codelen, uint8_t *sigmask, uint8_t *sig)
 {
     uint32_t magic;
     memcpy(&magic, data, 4);
@@ -13,7 +14,7 @@ bool parse_header(const uint8_t *data, uint32_t *codelen, uint8_t *sigidx, uint8
 
     uint32_t hdrlen;
     memcpy(&hdrlen, data + 4, 4);
-    if (hdrlen != 256) return false;
+    if (hdrlen != HEADER_SIZE) return false;
 
     uint32_t expiry;
     memcpy(&expiry, data + 8, 4);
@@ -21,7 +22,6 @@ bool parse_header(const uint8_t *data, uint32_t *codelen, uint8_t *sigidx, uint8
 
     uint32_t clen;
     memcpy(&clen, data + 12, 4);
-    // stage 2 (+header) must fit into sectors 4...11 - see docs/memory.md for more info
     if (clen + hdrlen < 4 * 1024) return false;
     if (clen + hdrlen > 64 * 1024 + 7 * 128 * 1024) return false;
     if ((clen + hdrlen) % 512 != 0) return false;
@@ -33,14 +33,14 @@ bool parse_header(const uint8_t *data, uint32_t *codelen, uint8_t *sigidx, uint8
     uint32_t version;
     memcpy(&version, data + 16, 4);
 
-    // uint8_t reserved[171];
+    // uint8_t reserved[427];
 
-    if (sigidx) {
-        memcpy(sigidx, data + 0x00BF, 1);
+    if (sigmask) {
+        memcpy(sigmask, data + 0x01BF, 1);
     }
 
     if (sig) {
-        memcpy(sig, data + 0x00C0, 64);
+        memcpy(sig, data + 0x01C0, 64);
     }
 
     return true;
@@ -79,9 +79,9 @@ const uint8_t *get_pubkey(uint8_t index)
 bool check_signature(const uint8_t *start)
 {
     uint32_t codelen;
-    uint8_t sigidx;
+    uint8_t sigmask;
     uint8_t sig[64];
-    if (!parse_header(start, &codelen, &sigidx, sig)) {
+    if (!parse_header(start, &codelen, &sigmask, sig)) {
         return false;
     }
 
@@ -95,7 +95,11 @@ bool check_signature(const uint8_t *start)
     blake2s_Update(&ctx, start + 256, codelen);
     blake2s_Final(&ctx, hash, BLAKE2S_DIGEST_LENGTH);
 
-    const uint8_t *pub = get_pubkey(sigidx);
+    const uint8_t *pub = get_pubkey(sigmask);
+
+    // TODO: remove debug skip of unsigned
+    if (!pub) return true;
+    // end
 
     return pub && (0 == ed25519_sign_open(hash, BLAKE2S_DIGEST_LENGTH, *(const ed25519_public_key *)pub, *(const ed25519_signature *)sig));
 }
diff --git a/micropython/bootloader/main.c b/micropython/bootloader/main.c
index 95398b412..e72f764f7 100644
--- a/micropython/bootloader/main.c
+++ b/micropython/bootloader/main.c
@@ -112,6 +112,27 @@ bool copy_sdcard(void)
     return true;
 }
 
+void check_and_jump(void)
+{
+    BOOTLOADER_PRINTLN("checking loader");
+    if (parse_header((const uint8_t *)LOADER_START, NULL, NULL, NULL)) {
+        BOOTLOADER_PRINTLN("valid loader header");
+        if (check_signature((const uint8_t *)LOADER_START)) {
+            BOOTLOADER_PRINTLN("valid loader signature");
+            // TODO: remove debug wait
+            BOOTLOADER_PRINTLN("waiting 1 second");
+            HAL_Delay(1000);
+            // end
+            BOOTLOADER_PRINTLN("JUMP!");
+            jump_to(LOADER_START + HEADER_SIZE);
+        } else {
+            BOOTLOADER_PRINTLN("invalid loader signature");
+        }
+    } else {
+        BOOTLOADER_PRINTLN("invalid loader header");
+    }
+}
+
 int main(void)
 {
     SCB->VTOR = BOOTLOADER_START;
@@ -127,32 +148,13 @@ int main(void)
     BOOTLOADER_PRINTLN("=================");
     BOOTLOADER_PRINTLN("starting bootloader");
 
-    // TODO: remove debug
-    BOOTLOADER_PRINTLN("waiting 1 second");
-    HAL_Delay(1000);
-    BOOTLOADER_PRINTLN("jumping to loader");
-    jump_to(LOADER_START + HEADER_SIZE);
-    // end
-
     if (check_sdcard()) {
         if (!copy_sdcard()) {
             __fatal_error("halt");
         }
     }
 
-    BOOTLOADER_PRINTLN("checking loader");
-    if (parse_header((const uint8_t *)LOADER_START, NULL, NULL, NULL)) {
-        BOOTLOADER_PRINTLN("valid loader header");
-        if (check_signature((const uint8_t *)LOADER_START)) {
-            BOOTLOADER_PRINTLN("valid loader signature");
-            BOOTLOADER_PRINTLN("JUMP!");
-            jump_to(LOADER_START + HEADER_SIZE);
-        } else {
-            BOOTLOADER_PRINTLN("invalid loader signature");
-        }
-    } else {
-        BOOTLOADER_PRINTLN("invalid loader header");
-    }
+    check_and_jump();
 
     __fatal_error("halt");
 
diff --git a/micropython/firmware/header.S b/micropython/firmware/header.S
index b14013f7d..5ea8e8105 100644
--- a/micropython/firmware/header.S
+++ b/micropython/firmware/header.S
@@ -1,20 +1,20 @@
 #include "version.h"
 
-	.section  .header,"a",%progbits
+    .section  .header,"a",%progbits
 
-	.type g_header, %object
-	.size g_header, .-g_header
+    .type g_header, %object
+    .size g_header, .-g_header
 
 g_header:
-	.byte 'T','R','Z','F'
-	.word g_header_end - g_header
-	.word 0   /* valid until */
-	.word _codelen
-	.byte VERSION_MAJOR
-	.byte VERSION_MINOR
-	.byte VERSION_PATCH
-	.byte VERSION_BUILD
-	. = . + 427 /* reserved */
-	.byte 0    /* sigindex */
-	. = . + 64 /* signatures */
+    .byte 'T','R','Z','F'            // magic
+    .word g_header_end - g_header    // hdrlen
+    .word 0                          // expiry
+    .word _codelen                   // codelen
+    .byte VERSION_MAJOR              // vmajor
+    .byte VERSION_MINOR              // vminor
+    .byte VERSION_PATCH              // vpatch
+    .byte VERSION_BUILD              // vbuild
+    . = . + 427                      // reserved
+    .byte 0                          // sigmask
+    . = . + 64                       // sig
 g_header_end:
diff --git a/micropython/firmware/memory.ld b/micropython/firmware/memory.ld
index c223b0c9e..4f9bddae4 100644
--- a/micropython/firmware/memory.ld
+++ b/micropython/firmware/memory.ld
@@ -34,7 +34,7 @@ SECTIONS
         . = ALIGN(4);
         *(.text*)          /* .text* sections (code) */
         *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */
-        . = ALIGN(4);
+        . = ALIGN(512);
         _etext = .;        /* define a global symbol at end of code */
     } >FLASH
 
@@ -51,7 +51,7 @@ SECTIONS
         _sdata = .;        /* create a global symbol at data start; used by startup code in order to initialise the .data section in RAM */
         *(.data*)          /* .data* sections */
 
-        . = ALIGN(4);
+        . = ALIGN(512);
         _edata = .;        /* define a global symbol at data end; used by startup code in order to initialise the .data section in RAM */
     } >RAM AT> FLASH
 
@@ -87,7 +87,7 @@ SECTIONS
 }
 
 /* RAM extents for the garbage collector */
-_codelen = SIZEOF(.flash) + SIZEOF(.data);
+_codelen = SIZEOF(.flash) + SIZEOF(.data) - 512;
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 _heap_start = _ebss; /* heap starts just after statically allocated memory */
diff --git a/micropython/loader/crypto.c b/micropython/loader/crypto.c
new file mode 100644
index 000000000..a26a11806
--- /dev/null
+++ b/micropython/loader/crypto.c
@@ -0,0 +1,105 @@
+#include <string.h>
+
+#include "blake2s.h"
+#include "ed25519-donna/ed25519.h"
+
+#include "common.h"
+#include "crypto.h"
+
+bool parse_header(const uint8_t *data, uint32_t *codelen, uint8_t *sigmask, uint8_t *sig)
+{
+    uint32_t magic;
+    memcpy(&magic, data, 4);
+    if (magic != 0x465A5254) return false; // TRZF
+
+    uint32_t hdrlen;
+    memcpy(&hdrlen, data + 4, 4);
+    if (hdrlen != HEADER_SIZE) return false;
+
+    uint32_t expiry;
+    memcpy(&expiry, data + 8, 4);
+    if (expiry != 0) return false;
+
+    uint32_t clen;
+    memcpy(&clen, data + 12, 4);
+    if (clen + hdrlen < 4 * 1024) return false;
+    if (clen + hdrlen > 7 * 128 * 1024) return false;
+    if ((clen + hdrlen) % 512 != 0) return false;
+
+    if (codelen) {
+        *codelen = clen;
+    }
+
+    uint32_t version;
+    memcpy(&version, data + 16, 4);
+
+    // uint8_t reserved[427];
+
+    if (sigmask) {
+        memcpy(sigmask, data + 0x01BF, 1);
+    }
+
+    if (sig) {
+        memcpy(sig, data + 0x01C0, 64);
+    }
+
+    return true;
+}
+
+#define KEYMASK(A, B, C) ((1 << (A - 1)) | (1 << (B - 1)) | (1 << (C - 1)))
+
+const uint8_t *get_pubkey(uint8_t index)
+{
+    switch (index) {
+        case KEYMASK(1, 2, 3):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(1, 2, 4):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(1, 2, 5):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(1, 3, 4):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(1, 3, 5):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(1, 4, 5):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(2, 3, 4):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(2, 3, 5):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(2, 4, 5):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        case KEYMASK(3, 4, 5):
+            return (const uint8_t *)"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
+        default:
+            return NULL;
+    }
+}
+
+bool check_signature(const uint8_t *start)
+{
+    uint32_t codelen;
+    uint8_t sigmask;
+    uint8_t sig[64];
+    if (!parse_header(start, &codelen, &sigmask, sig)) {
+        return false;
+    }
+
+    uint8_t hash[BLAKE2S_DIGEST_LENGTH];
+    BLAKE2S_CTX ctx;
+    blake2s_Init(&ctx, BLAKE2S_DIGEST_LENGTH);
+    blake2s_Update(&ctx, start, 256 - 65);
+    for (int i = 0; i < 65; i++) {
+        blake2s_Update(&ctx, (const uint8_t *)"\x00", 1);
+    }
+    blake2s_Update(&ctx, start + 256, codelen);
+    blake2s_Final(&ctx, hash, BLAKE2S_DIGEST_LENGTH);
+
+    const uint8_t *pub = get_pubkey(sigmask);
+
+    // TODO: remove debug skip of unsigned
+    if (!pub) return true;
+    // end
+
+    return pub && (0 == ed25519_sign_open(hash, BLAKE2S_DIGEST_LENGTH, *(const ed25519_public_key *)pub, *(const ed25519_signature *)sig));
+}
diff --git a/micropython/loader/crypto.h b/micropython/loader/crypto.h
new file mode 100644
index 000000000..9d618cdfb
--- /dev/null
+++ b/micropython/loader/crypto.h
@@ -0,0 +1,11 @@
+#ifndef __LOADER_CRYPTO_H__
+#define __LOADER_CRYPTO_H__
+
+#include <stdint.h>
+#include <stdbool.h>
+
+bool parse_header(const uint8_t *data, uint32_t *codelen, uint8_t *sigidx, uint8_t *sig);
+
+bool check_signature(const uint8_t *start);
+
+#endif
diff --git a/micropython/loader/header.S b/micropython/loader/header.S
index ecba753cf..7bd93367f 100644
--- a/micropython/loader/header.S
+++ b/micropython/loader/header.S
@@ -1,20 +1,20 @@
 #include "version.h"
 
-	.section  .header,"a",%progbits
+    .section  .header,"a",%progbits
 
-	.type g_header, %object
-	.size g_header, .-g_header
+    .type g_header, %object
+    .size g_header, .-g_header
 
 g_header:
-	.byte 'T','R','Z','L'
-	.word g_header_end - g_header
-	.word 0   /* valid until */
-	.word _codelen
-	.byte VERSION_MAJOR
-	.byte VERSION_MINOR
-	.byte VERSION_PATCH
-	.byte VERSION_BUILD
-	. = . + 427 /* reserved */
-	.byte 0    /* sigindex */
-	. = . + 64 /* signatures */
+    .byte 'T','R','Z','L'            // magic
+    .word g_header_end - g_header    // hdrlen
+    .word 0                          // expiry
+    .word _codelen                   // codelen
+    .byte VERSION_MAJOR              // vmajor
+    .byte VERSION_MINOR              // vminor
+    .byte VERSION_PATCH              // vpatch
+    .byte VERSION_BUILD              // vbuild
+    . = . + 427                      // reserved
+    .byte 0                          // sigmask
+    . = . + 64                       // sig
 g_header_end:
diff --git a/micropython/loader/main.c b/micropython/loader/main.c
index 2bc1c5fd9..479fed92d 100644
--- a/micropython/loader/main.c
+++ b/micropython/loader/main.c
@@ -2,6 +2,7 @@
 
 #include "common.h"
 #include "display.h"
+#include "crypto.h"
 
 #define LOADER_FGCOLOR 0xFFFF
 #define LOADER_BGCOLOR 0x0000
@@ -13,6 +14,27 @@ void pendsv_isr_handler(void) {
     __fatal_error("pendsv");
 }
 
+void check_and_jump(void)
+{
+    LOADER_PRINTLN("checking firmware");
+    if (parse_header((const uint8_t *)FIRMWARE_START, NULL, NULL, NULL)) {
+        LOADER_PRINTLN("valid firmware header");
+        if (check_signature((const uint8_t *)FIRMWARE_START)) {
+            LOADER_PRINTLN("valid firmware signature");
+            LOADER_PRINTLN("JUMP!");
+            // TODO: remove debug wait
+            LOADER_PRINTLN("waiting 1 second");
+            HAL_Delay(1000);
+            // end
+            jump_to(FIRMWARE_START + HEADER_SIZE);
+        } else {
+            LOADER_PRINTLN("invalid firmware signature");
+        }
+    } else {
+        LOADER_PRINTLN("invalid firmware header");
+    }
+}
+
 int main(void)
 {
     SCB->VTOR = LOADER_START + HEADER_SIZE;
@@ -22,12 +44,13 @@ int main(void)
     display_clear();
     display_backlight(255);
 
-    LOADER_PRINTLN("reached loader");
-    LOADER_PRINTLN("waiting 1 second");
-    HAL_Delay(1000);
-    LOADER_PRINTLN("jumping to firmware");
+    LOADER_PRINTLN("TREZOR Loader");
+    LOADER_PRINTLN("=============");
+    LOADER_PRINTLN("starting loader");
 
-    jump_to(FIRMWARE_START + HEADER_SIZE);
+    check_and_jump();
+
+    __fatal_error("halt");
 
     return 0;
 }
diff --git a/micropython/loader/memory.ld b/micropython/loader/memory.ld
index 651995f07..0651b48b1 100644
--- a/micropython/loader/memory.ld
+++ b/micropython/loader/memory.ld
@@ -29,12 +29,12 @@ SECTIONS
     .flash :
     {
         . = ALIGN(4);
-	KEEP(*(.header))
+        KEEP(*(.header))     /* Firmware Header */
         KEEP(*(.isr_vector)) /* Startup code */
         . = ALIGN(4);
         *(.text*)          /* .text* sections (code) */
         *(.rodata*)        /* .rodata* sections (constants, strings, etc.) */
-        . = ALIGN(4);
+        . = ALIGN(512);
         _etext = .;        /* define a global symbol at end of code */
     } >FLASH
 
@@ -51,9 +51,8 @@ SECTIONS
         _sdata = .;        /* create a global symbol at data start; used by startup code in order to initialise the .data section in RAM */
         *(.data*)          /* .data* sections */
 
-        . = ALIGN(4);
+        . = ALIGN(512);
         _edata = .;        /* define a global symbol at data end; used by startup code in order to initialise the .data section in RAM */
-	_datalen = . - _sdata;
     } >RAM AT> FLASH
 
     /* Uninitialized data section */
@@ -88,7 +87,7 @@ SECTIONS
 }
 
 /* RAM extents for the garbage collector */
-_codelen = SIZEOF(.flash) + SIZEOF(.data);
+_codelen = SIZEOF(.flash) + SIZEOF(.data) - 512;
 _ram_start = ORIGIN(RAM);
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 _heap_start = _ebss; /* heap starts just after statically allocated memory */
diff --git a/tools/binctl b/tools/binctl
index 398f6d9dd..883c297b5 100755
--- a/tools/binctl
+++ b/tools/binctl
@@ -6,22 +6,22 @@ import ed25519
 import pyblake2
 
 
-# loader/firmware headers specification: https://github.com/trezor/trezor-core/blob/master/docs/bootloader.md
-
-
 def get_sig(data):
     print('Enter privkey: ', end='')
     seckey = binascii.unhexlify(input())
     signkey = ed25519.SigningKey(seckey)
     digest = pyblake2.blake2s(data).digest()
-    sigidx = 0x01 # (1 _ _ _ _)
+    sigmask = 0x01 # (1 _ _ _ _)
     sig = signkey.sign(digest)
-    return sigidx, sig
+    return sigmask, sig
 
 
-class LoaderImage:
+# loader/firmware headers specification: https://github.com/trezor/trezor-core/blob/master/docs/bootloader.md
 
-    def __init__(self, data):
+
+class BinImage:
+
+    def __init__(self, data, magic, max_size):
         header = struct.unpack('<4sIIIBBBB427sB64s', data[:512])
         self.magic, \
         self.hdrlen, \
@@ -32,25 +32,31 @@ class LoaderImage:
         self.vpatch, \
         self.vbuild, \
         self.reserved, \
-        self.sigidx, \
+        self.sigmask, \
         self.sig = header
-        assert self.magic == b'TRZL'
+        assert self.magic == magic
         assert self.hdrlen == 512
-        assert self.codelen + self.hdrlen >= 4 * 1024
-        assert self.codelen + self.hdrlen <= 64 * 1024 + 7 * 128 * 1024
-        assert (self.codelen + self.hdrlen) % 512 == 0
+        total_len = self.hdrlen + self.codelen
+        assert total_len % 512 == 0
+        assert total_len >= 4 * 1024
+        assert total_len <= max_size
         assert self.reserved == 427 * b'\x00'
         self.code = data[self.hdrlen:]
         assert len(self.code) == self.codelen
 
     def print(self):
-        print('TREZOR Loader Image')
+        if self.magic == b'TRZF':
+            print('TREZOR Firmware Image')
+        elif self.magic == b'TRZL':
+            print('TREZOR Loader Image')
+        else:
+            print('TREZOR Unknown Image')
         print('  * magic   :', self.magic.decode('ascii'))
         print('  * hdrlen  :', self.hdrlen)
         print('  * expiry  :', self.expiry)
         print('  * codelen :', self.codelen)
         print('  * version : %d.%d.%d.%d' % (self.vmajor, self.vminor, self.vpatch, self.vbuild))
-        print('  * sigidx  :', self.sigidx)
+        print('  * sigmask :', self.sigmask)
         print('  * sig     :', binascii.hexlify(self.sig).decode('ascii'))
 
     def serialize_header(self, sig=True):
@@ -59,7 +65,7 @@ class LoaderImage:
             self.vmajor, self.vminor, self.vpatch, self.vbuild, \
             self.reserved)
         if sig:
-            header += struct.pack('<B64s', self.sigidx, self.sig)
+            header += struct.pack('<B64s', self.sigmask, self.sig)
         else:
             header += 65 * b'\x00'
         assert len(header) == self.hdrlen
@@ -69,7 +75,7 @@ class LoaderImage:
         header = self.serialize_header(sig=False)
         data = header + self.code
         assert len(data) == self.hdrlen + self.codelen
-        self.sigidx, self.sig = get_sig(data)
+        self.sigmask, self.sig = get_sig(data)
 
     def write(self, filename):
         with open(filename, 'wb') as f:
@@ -77,6 +83,19 @@ class LoaderImage:
             f.write(self.code)
 
 
+class FirmwareImage(BinImage):
+
+    def __init__(self, data):
+        super().__init__(data, magic=b'TRZF', max_size=7*128*1024)
+
+
+class LoaderImage(BinImage):
+
+    def __init__(self, data):
+        super().__init__(data, magic=b'TRZL', max_size=64*1024 + 7*128*1024)
+
+
+"""
 class VendorHeader:
 
     def __init__(self, data):
@@ -104,7 +123,7 @@ class VendorHeader:
         p += 2
         self.vimg = data[p:p + self.vimg_len]
         p += self.vimg_len
-        self.sigidx = data[p]
+        self.sigmask = data[p]
         p += 1
         self.sig = data[p:p+64]
         assert len(data) == 4 + 4 + 4 + 1 + 1 + 1 + 1 + \
@@ -124,8 +143,8 @@ class VendorHeader:
             print('  * vpub #%d :' % (i + 1), binascii.hexlify(self.vpub[i]).decode('ascii'))
         print('  * vstr     :', self.vstr.decode('ascii'))
         print('  * vimg     : (%d bytes)', len(self.vimg))
-        print('  * sigidx  :', self.sigidx)
-        print('  * sig     :', binascii.hexlify(self.sig).decode('ascii'))
+        print('  * sigmask  :', self.sigmask)
+        print('  * sig      :', binascii.hexlify(self.sig).decode('ascii'))
 
     def serialize_header(self, sig=True):
         header = struct.pack('<4sIIBBBB', \
@@ -137,7 +156,7 @@ class VendorHeader:
         header += struct.pack('<B', self.vstr_len) + self.vstr
         header += struct.pack('<H', self.vimg_len) + self.vimg
         if sig:
-            header += struct.pack('<B64s', self.sigidx, self.sig)
+            header += struct.pack('<B64s', self.sigmask, self.sig)
         else:
             header += 65 * b'\x00'
         assert len(header) == self.hdrlen
@@ -145,67 +164,12 @@ class VendorHeader:
 
     def sign(self):
         header = self.serialize_header(sig=False)
-        self.sigidx, self.sig = get_sig(header)
+        self.sigmask, self.sig = get_sig(header)
 
     def write(self, filename):
         with open(filename, 'wb') as f:
             f.write(self.serialize_header())
-
-
-class FirmwareImage:
-
-    def __init__(self, data):
-        header = struct.unpack('<4sIIIBBBB427sB64s', data[:512])
-        self.magic, \
-        self.hdrlen, \
-        self.expiry, \
-        self.codelen, \
-        self.vmajor, \
-        self.vminor, \
-        self.vpatch, \
-        self.vbuild, \
-        self.reserved, \
-        self.sigidx, \
-        self.sig = header
-        assert self.magic == b'TRZF'
-        assert self.hdrlen == 512
-        assert self.codelen % 4 == 0
-        assert self.reserved == 427 * b'\x00'
-        self.code = data[self.hdrlen:]
-        assert len(self.code) == self.codelen
-
-    def print(self):
-        print('TREZOR Firmware Image')
-        print('  * magic   :', self.magic.decode('ascii'))
-        print('  * hdrlen  :', self.hdrlen)
-        print('  * expiry  :', self.expiry)
-        print('  * codelen :', self.codelen)
-        print('  * version : %d.%d.%d.%d' % (self.vmajor, self.vminor, self.vpatch, self.vbuild))
-        print('  * sigidx  :', self.sigidx)
-        print('  * sig     :', binascii.hexlify(self.sig).decode('ascii'))
-
-    def serialize_header(self, sig=True):
-        header = struct.pack('<4sIIIBBBB427s', \
-            self.magic, self.hdrlen, self.expiry, self.codelen, \
-            self.vmajor, self.vminor, self.vpatch, self.vbuild, \
-            self.reserved)
-        if sig:
-            header += struct.pack('<B64s', self.sigidx, self.sig)
-        else:
-            header += 65 * b'\x00'
-        assert len(header) == self.hdrlen
-        return header
-
-    def sign(self):
-        header = self.serialize_header(sig=False)
-        data = header + self.code
-        assert len(data) == self.hdrlen + self.codelen
-        self.sigidx, self.sig = get_sig(data)
-
-    def write(self, filename):
-        with open(filename, 'wb') as f:
-            f.write(self.serialize_header())
-            f.write(self.code)
+"""
 
 
 def binopen(filename):
@@ -216,10 +180,10 @@ def binopen(filename):
     magic = data[:4]
     if magic == b'TRZL':
         return LoaderImage(data)
-    if magic == b'TRZV':
-        return VendorHeader(data)
     if magic == b'TRZF':
         return FirmwareImage(data)
+    # if magic == b'TRZV':
+    #     return VendorHeader(data)
     raise Exception('Unknown file format')