Fetch seed / RNG / attestation / user keys / appname / appversion from env at startup then stick with it

CHANGELOG.md

@@ -5,6 +5,19 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.5.0] - 2024-??-??
+
+### Added
+- Attestation key or user private keys can now be configured with the new `--attestation-key`
+  and `--user-private-key` arguments (or `ATTESTATION_PRIVATE_KEY` and `USER_PRIVATE_KEY` through
+  environment variables). User certificates are correctly calculated signed from the user private
+  keys and the attestation key.
+
+### Changed
+- Seed, RNG, application name and version are now fetched from the environment when Speculos starts
+  then stored internally for further use, rather than fetched when needed during runtime. This
+  avoids several Speculos instances from messing up with each other's environment variables.
+
 ## [0.4.1] - 2023-12-19
 
 ### Fixed

CMakeLists.txt

@@ -136,7 +136,7 @@ link_libraries(ssl crypto dl blst)
 add_subdirectory(src)
 
 if (BUILD_TESTING)
-  add_subdirectory(tests/syscalls)
+  add_subdirectory(tests/c/)
 endif()
 
 add_custom_target(

speculos/main.py

@@ -227,6 +227,11 @@ def run_qemu(s1: socket.socket, s2: socket.socket, args: argparse.Namespace) ->
     if args.deterministic_rng:
         os.environ['RNG_SEED'] = args.deterministic_rng
 
+    if args.user_private_key:
+        os.environ['USER_PRIVATE_KEY'] = args.user_private_key
+    if args.attestation_key:
+        os.environ['ATTESTATION_PRIVATE_KEY'] = args.attestation_key
+
     logger.debug(f"executing qemu: {argv}")
     try:
         os.execvp(argv[0], argv)
@@ -260,8 +265,12 @@ def main(prog=None) -> int:
                                                        'to specify a path')
     parser.add_argument('--color', default='MATTE_BLACK', choices=list(display.COLORS.keys()), help='Nano color')
     parser.add_argument('-d', '--debug', action='store_true', help='Wait gdb connection to port 1234')
-    parser.add_argument('--deterministic-rng', default="", help='Seed the rng with a given value to produce '
+    parser.add_argument('--deterministic-rng', default='', help='Seed the rng with a given value to produce '
                                                                 'deterministic randomness')
+    parser.add_argument('--user-private-key', default='',
+                        help='32B in hex format, will be used as the user private keys')
+    parser.add_argument('--attestation-key', default='', help='32B in hex format, will be used as the private '
+                                                              'attestation key')
     parser.add_argument('-k', '--sdk', type=str, help='SDK version')
     parser.add_argument('-a', '--apiLevel', type=str, help='Api level')
     parser.add_argument('-l', '--library', default=[], action='append', help='Additional library (eg. '

src/CMakeLists.txt

@@ -56,6 +56,7 @@ add_library(emu
         emulate_blue_2.2.5.c
         emulate_lnsp_1.0.c
         emulate_unified_sdk.c
+        environment.c
         svc.c)
 
 add_dependencies(emu openssl)

src/bolos/cx.c

@@ -4,32 +4,20 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <time.h>
 #include <unistd.h>
 
 #include "emulate.h"
+#include "environment.h"
 
 static bool initialized = false;
 
-static unsigned int get_rng_seed_from_env(const char *name)
-{
-  char *p;
-
-  p = getenv(name);
-  if (p != NULL) {
-    return atoi(p);
-  } else {
-    return time(NULL);
-  }
-}
-
 /* not secure, but this is clearly not the goal of this emulator */
 unsigned long sys_cx_rng(uint8_t *buffer, unsigned int length)
 {
   unsigned int i;
 
   if (!initialized) {
-    srand(get_rng_seed_from_env("RNG_SEED"));
+    srand(env_get_rng());
     initialized = true;
   }
 

src/bolos/cx_ec.c

@@ -1652,7 +1652,6 @@ int sys_cx_ecdsa_sign(const cx_ecfp_private_key_t *key, int mode,
   BIGNUM *normalized_s = BN_new();
   ECDSA_SIG_get0(ecdsa_sig, &r, &s);
   if ((mode & CX_NO_CANONICAL) == 0 && BN_cmp(s, halfn) > 0) {
-    fprintf(stderr, "cx_ecdsa_sign: normalizing s > n/2\n");
     BN_sub(normalized_s, n, s);
     if (info != NULL) {
       *info ^= CX_ECCINFO_PARITY_ODD; // Inverse the bit

src/bolos/endorsement.c

@@ -3,51 +3,10 @@
 #include "bolos/exception.h"
 #include "cx.h"
 #include "emulate.h"
+#include "environment.h"
 
 #define cx_ecdsa_init_public_key sys_cx_ecfp_init_public_key
 
-// TODO: all keys are currently hardcoded
-
-static cx_ecfp_private_key_t user_private_key_1 = {
-  CX_CURVE_256K1,
-  32,
-  { 0xe1, 0x5e, 0x01, 0xd4, 0x70, 0x82, 0xf0, 0xea, 0x47, 0x71, 0xc9,
-    0x9f, 0xe3, 0x12, 0xf9, 0xd7, 0x00, 0x93, 0xc8, 0x9a, 0xf4, 0x77,
-    0x87, 0xfd, 0xf8, 0x2e, 0x03, 0x1f, 0x67, 0x28, 0xb7, 0x10 },
-};
-
-static cx_ecfp_private_key_t user_private_key_2 = {
-  CX_CURVE_256K1,
-  32,
-  { 0xe1, 0x5e, 0x01, 0xd4, 0x70, 0x82, 0xf0, 0xea, 0x47, 0x71, 0xc9,
-    0x9f, 0xe3, 0x12, 0xf9, 0xd7, 0x00, 0x93, 0xc8, 0x9a, 0xf4, 0x77,
-    0x87, 0xfd, 0xf8, 0x2e, 0x03, 0x1f, 0x67, 0x28, 0xb7, 0x10 },
-};
-
-// user_private_key_1 signed by test owner private key
-// "138fb9b91da745f12977a2b46f0bce2f0418b50fcb76631baf0f08ceefdb5d57"
-static uint8_t user_certificate_1[] = {
-  0x30, 0x45, 0x02, 0x21, 0x00, 0xbf, 0x23, 0x7e, 0x5b, 0x40, 0x06, 0x14,
-  0x17, 0xf6, 0x62, 0xa6, 0xd0, 0x8a, 0x4b, 0xde, 0x1f, 0xe3, 0x34, 0x3b,
-  0xd8, 0x70, 0x8c, 0xed, 0x04, 0x6c, 0x84, 0x17, 0x49, 0x5a, 0xd3, 0x6c,
-  0xcf, 0x02, 0x20, 0x3d, 0x39, 0xa5, 0x32, 0xee, 0xca, 0xdf, 0xf6, 0xdf,
-  0x20, 0x53, 0xe4, 0xab, 0x98, 0x96, 0xaa, 0x00, 0xf3, 0xbe, 0xf1, 0x5c,
-  0x4b, 0xd1, 0x1c, 0x53, 0x66, 0x1e, 0x54, 0xfe, 0x5e, 0x2f, 0xf4
-};
-static const uint8_t user_certificate_1_length = sizeof(user_certificate_1);
-
-// user_private_key_2 signed by test owner private key
-// "138fb9b91da745f12977a2b46f0bce2f0418b50fcb76631baf0f08ceefdb5d57"
-static uint8_t user_certificate_2[] = {
-  0x30, 0x45, 0x02, 0x21, 0x00, 0xbf, 0x23, 0x7e, 0x5b, 0x40, 0x06, 0x14,
-  0x17, 0xf6, 0x62, 0xa6, 0xd0, 0x8a, 0x4b, 0xde, 0x1f, 0xe3, 0x34, 0x3b,
-  0xd8, 0x70, 0x8c, 0xed, 0x04, 0x6c, 0x84, 0x17, 0x49, 0x5a, 0xd3, 0x6c,
-  0xcf, 0x02, 0x20, 0x3d, 0x39, 0xa5, 0x32, 0xee, 0xca, 0xdf, 0xf6, 0xdf,
-  0x20, 0x53, 0xe4, 0xab, 0x98, 0x96, 0xaa, 0x00, 0xf3, 0xbe, 0xf1, 0x5c,
-  0x4b, 0xd1, 0x1c, 0x53, 0x66, 0x1e, 0x54, 0xfe, 0x5e, 0x2f, 0xf4
-};
-static uint8_t user_certificate_2_length;
-
 unsigned int sys_os_endorsement_get_code_hash(uint8_t *buffer)
 {
   memcpy(buffer, "12345678abcdef0000fedcba87654321", 32);
@@ -61,10 +20,10 @@ unsigned long sys_os_endorsement_get_public_key(uint8_t index, uint8_t *buffer)
 
   switch (index) {
   case 1:
-    privateKey = &user_private_key_1;
+    privateKey = env_get_user_private_key(1);
     break;
   case 2:
-    privateKey = &user_private_key_2;
+    privateKey = env_get_user_private_key(2);
     break;
   default:
     THROW(EXCEPTION);
@@ -93,30 +52,27 @@ unsigned int
 sys_os_endorsement_get_public_key_certificate(unsigned char index,
                                               unsigned char *buffer)
 {
-  unsigned char *certificate;
-  unsigned char length;
+  env_user_certificate_t *certificate;
 
   switch (index) {
   case 1:
-    length = user_certificate_1_length;
-    certificate = user_certificate_1;
+    certificate = env_get_user_certificate(1);
     break;
   case 2:
-    length = user_certificate_2_length;
-    certificate = user_certificate_2;
+    certificate = env_get_user_certificate(2);
     break;
   default:
     THROW(EXCEPTION);
     break;
   }
 
-  if (length == 0) {
+  if (certificate->length == 0) {
     THROW(EXCEPTION);
   }
 
-  memcpy(buffer, certificate, length);
+  memcpy(buffer, certificate->buffer, certificate->length);
 
-  return length;
+  return certificate->length;
 }
 
 unsigned int sys_os_endorsement_get_public_key_certificate_new(
@@ -140,7 +96,8 @@ unsigned long sys_os_endorsement_key1_sign_data(uint8_t *data,
   sys_cx_hash((cx_hash_t *)&sha256, CX_LAST, hash, sizeof(hash), hash, 32);
   /* XXX: CX_RND_TRNG is set but actually ignored by speculos'
    *      sys_cx_ecdsa_sign implementation */
-  sys_cx_ecdsa_sign(&user_private_key_1, CX_LAST | CX_RND_TRNG, CX_SHA256, hash,
+  sys_cx_ecdsa_sign(env_get_user_private_key(1), CX_LAST | CX_RND_TRNG,
+                    CX_SHA256, hash,
                     sizeof(hash),          // size of SHA256 hash
                     signature, 6 + 33 * 2, /*3TL+2V*/
                     NULL);

src/bolos/os.c

@@ -3,15 +3,13 @@
 #include <unistd.h>
 
 #include "emulate.h"
+#include "environment.h"
 #include "svc.h"
 
 #define OS_SETTING_PLANEMODE_OLD 5
 #define OS_SETTING_PLANEMODE_NEW 6
 #define OS_SETTING_SOUND         9
 
-#define BOLOS_TAG_APPNAME    0x01
-#define BOLOS_TAG_APPVERSION 0x02
-
 #undef PATH_MAX
 #define PATH_MAX 1024
 
@@ -69,56 +67,7 @@ unsigned long sys_os_registry_get_current_app_tag(unsigned int tag,
                                                   uint8_t *buffer,
                                                   size_t length)
 {
-  const char *name;
-  const char *version;
-  const char *str;
-  char *str_dup = NULL;
-
-  if (length < 1) {
-    return 0;
-  }
-
-  name = "app";
-  version = "1.33.7";
-
-  str = getenv("SPECULOS_APPNAME");
-  if (str == NULL) {
-    str = getenv("SPECULOS_DETECTED_APPNAME");
-  }
-
-  if (str != NULL) {
-    str_dup = strdup(str);
-    if (str_dup != NULL) {
-      char *p = strstr(str_dup, ":");
-      if (p != NULL) {
-        *p = '\x00';
-        name = str_dup;
-        version = p + 1;
-      }
-    }
-  }
-
-  switch (tag) {
-  case BOLOS_TAG_APPNAME:
-    strncpy((char *)buffer, name, length);
-    length = MIN(length, strlen(name));
-    break;
-  case BOLOS_TAG_APPVERSION:
-    strncpy((char *)buffer, version, length);
-    length = MIN(length, strlen(version));
-    break;
-  default:
-    length = 0;
-    break;
-  }
-
-  buffer[length] = '\x00';
-
-  if (str_dup != NULL) {
-    free(str_dup);
-  }
-
-  return length;
+  return env_get_app_tag((char *)buffer, length, tag);
 }
 
 unsigned long sys_os_lib_call(unsigned long *call_parameters)

src/bolos/os_bip32.c

@@ -9,24 +9,15 @@
 #include "cx.h"
 #include "cx_utils.h"
 #include "emulate.h"
+#include "environment.h"
 
 #define BIP32_HARDEN_MASK      0x80000000
 #define BIP32_SECP_SEED_LENGTH 12
-#define MAX_SEED_SIZE          64
 
 #define cx_ecfp_generate_pair     sys_cx_ecfp_generate_pair
 #define cx_ecfp_init_private_key  sys_cx_ecfp_init_private_key
 #define cx_ecdsa_init_private_key cx_ecfp_init_private_key
 
-/* glory promote mansion idle axis finger extra february uncover one trip
- * resource lawn turtle enact monster seven myth punch hobby comfort wild raise
- * skin */
-static uint8_t default_seed[MAX_SEED_SIZE] =
-    "\xb1\x19\x97\xfa\xff\x42\x0a\x33\x1b\xb4\xa4\xff\xdc\x8b\xdc\x8b\xa7\xc0"
-    "\x17\x32\xa9\x9a\x30\xd8\x3d\xbb\xeb\xd4\x69\x66\x6c\x84\xb4\x7d\x09\xd3"
-    "\xf5\xf4\x72\xb3\xb9\x38\x4a\xc6\x34\xbe\xba\x2a\x44\x0b\xa3\x6e\xc7\x66"
-    "\x11\x44\x13\x2f\x35\xe2\x06\x87\x35\x64";
-
 static uint8_t const BIP32_SECP_SEED[] = { 'B', 'i', 't', 'c', 'o', 'i',
                                            'n', ' ', 's', 'e', 'e', 'd' };
 
@@ -166,65 +157,6 @@ static void expand_seed(cx_curve_t curve, const uint8_t *sk, size_t sk_length,
   }
 }
 
-int unhex(uint8_t *dst, size_t dst_size, const char *src, size_t src_size)
-{
-  unsigned int i;
-  uint8_t acc;
-  int8_t c;
-
-  acc = 0;
-  for (i = 0; i < src_size && (i >> 1) < dst_size; i++) {
-    c = src[i];
-    switch (c) {
-    case '0' ... '9':
-      acc = (acc << 4) + c - '0';
-      break;
-    case 'a' ... 'f':
-      acc = (acc << 4) + c - 'a' + 10;
-      break;
-    case 'A' ... 'F':
-      acc = (acc << 4) + c - 'A' + 10;
-      break;
-    default:
-      return -1;
-    }
-
-    if (i % 2 != 0) {
-      dst[i >> 1] = acc;
-      acc = 0;
-    }
-  }
-
-  if (i != src_size) {
-    return -1;
-  }
-
-  return src_size / 2;
-}
-
-size_t get_seed_from_env(const char *name, uint8_t *seed, size_t max_size)
-{
-  ssize_t seed_size;
-  char *p;
-
-  p = getenv(name);
-  if (p != NULL) {
-    seed_size = unhex(seed, max_size, p, strlen(p));
-    if (seed_size < 0) {
-      warnx("invalid seed passed through %s environment variable", name);
-      p = NULL;
-    }
-  }
-
-  if (p == NULL) {
-    warnx("using default seed");
-    memcpy(seed, default_seed, sizeof(default_seed));
-    seed_size = sizeof(default_seed);
-  }
-
-  return seed_size;
-}
-
 static int hdw_bip32_ed25519(extended_private_key *key, const uint32_t *path,
                              size_t length, uint8_t *private_key,
                              uint8_t *chain)
@@ -512,7 +444,7 @@ unsigned long sys_os_perso_derive_node_with_seed_key(
     sk_length = seed_key_length;
   }
 
-  seed_size = get_seed_from_env("SPECULOS_SEED", seed, sizeof(seed));
+  seed_size = env_get_seed(seed, sizeof(seed));
 
   if (mode == HDW_SLIP21) {
     ret = hdw_slip21(sk, sk_length, seed, seed_size, (const uint8_t *)path,