/**
 * Author......: See docs/credits.txt
 * License.....: MIT
 */

#include "common.h"
#include "types.h"
#include "modules.h"
#include "bitops.h"
#include "convert.h"
#include "shared.h"
#include "emu_inc_hash_md5.h"
#include "memory.h"

static const u32   ATTACK_EXEC    = ATTACK_EXEC_INSIDE_KERNEL;
static const u32   DGST_POS0      = 0;
static const u32   DGST_POS1      = 1;
static const u32   DGST_POS2      = 2;
static const u32   DGST_POS3      = 3;
static const u32   DGST_SIZE      = DGST_SIZE_4_16;
static const u32   HASH_CATEGORY  = HASH_CATEGORY_NETWORK_PROTOCOL;
static const char *HASH_NAME      = "JWT (JSON Web Token)";
static const u64   KERN_TYPE      = 16511;
static const u32   OPTI_TYPE      = OPTI_TYPE_ZERO_BYTE
                                  | OPTI_TYPE_NOT_ITERATED;
static const u64   OPTS_TYPE      = OPTS_TYPE_PT_GENERATE_BE
                                  | OPTS_TYPE_SELF_TEST_DISABLE;
static const u32   SALT_TYPE      = SALT_TYPE_EMBEDDED;
static const char *ST_PASS        = "hashcat";
static const char *ST_HASH        = "eyJhbGciOiJIUzI1NiJ9.eyIzNDM2MzQyMCI6NTc2ODc1NDd9.f1nXZ3V_Hrr6ee-AFCTLaHRnrkiKmio2t3JqwL32guY";

u32         module_attack_exec    (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return ATTACK_EXEC;     }
u32         module_dgst_pos0      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return DGST_POS0;       }
u32         module_dgst_pos1      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return DGST_POS1;       }
u32         module_dgst_pos2      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return DGST_POS2;       }
u32         module_dgst_pos3      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return DGST_POS3;       }
u32         module_dgst_size      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return DGST_SIZE;       }
u32         module_hash_category  (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return HASH_CATEGORY;   }
const char *module_hash_name      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return HASH_NAME;       }
u64         module_kern_type      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return KERN_TYPE;       }
u32         module_opti_type      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return OPTI_TYPE;       }
u64         module_opts_type      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return OPTS_TYPE;       }
u32         module_salt_type      (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return SALT_TYPE;       }
const char *module_st_hash        (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return ST_HASH;         }
const char *module_st_pass        (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra) { return ST_PASS;         }

typedef struct jwt
{
  u32 salt_buf[1024];
  u32 salt_len;

  u32 signature_len;

} jwt_t;

typedef enum kern_type_jwt
{
  KERN_TYPE_JWT_HS256 = 16511,
  KERN_TYPE_JWT_HS384 = 16512,
  KERN_TYPE_JWT_HS512 = 16513,

} kern_type_jwt_t;

salt_t *module_benchmark_salt (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra)
{
  salt_t *salt = (salt_t *) hcmalloc (sizeof (salt_t));

  salt->salt_iter = 1;
  salt->salt_len  = 16;

  return salt;
}

void *module_benchmark_esalt (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra)
{
  jwt_t *jwt = (jwt_t *) hcmalloc (sizeof (jwt_t));

  jwt->signature_len = 43;
  jwt->salt_len      = 32;

  return jwt;
}

u64 module_esalt_size (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const user_options_t *user_options, MAYBE_UNUSED const user_options_extra_t *user_options_extra)
{
  const u64 esalt_size = (const u64) sizeof (jwt_t);

  return esalt_size;
}

u64 module_kern_type_dynamic (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const void *digest_buf, MAYBE_UNUSED const salt_t *salt, MAYBE_UNUSED const void *esalt_buf, MAYBE_UNUSED const void *hook_salt_buf, MAYBE_UNUSED const hashinfo_t *hash_info)
{
  const jwt_t *jwt = (const jwt_t *) esalt_buf;

  u64 kern_type = -1;

  // it would be more accurate to base64 decode the header_pos buffer and then to string match HS256 - same goes for the other algorithms

  if (jwt->signature_len == 43)
  {
    kern_type = KERN_TYPE_JWT_HS256;
  }
  else if (jwt->signature_len == 64)
  {
    kern_type = KERN_TYPE_JWT_HS384;
  }
  else if (jwt->signature_len == 86)
  {
    kern_type = KERN_TYPE_JWT_HS512;
  }
  else
  {
    return (PARSER_HASH_LENGTH);
  }

  return kern_type;
}

int module_hash_decode (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED void *digest_buf, MAYBE_UNUSED salt_t *salt, MAYBE_UNUSED void *esalt_buf, MAYBE_UNUSED void *hook_salt_buf, MAYBE_UNUSED hashinfo_t *hash_info, const char *line_buf, MAYBE_UNUSED const int line_len)
{
  jwt_t *jwt = (jwt_t *) esalt_buf;

  token_t token;

  token.token_cnt  = 3;

  token.sep[0]     = '.';
  token.len_min[0] = 1;
  token.len_max[0] = 2047;
  token.attr[0]    = TOKEN_ATTR_VERIFY_LENGTH
                   | TOKEN_ATTR_VERIFY_BASE64C;

  token.sep[1]     = '.';
  token.len_min[1] = 1;
  token.len_max[1] = 2047;
  token.attr[1]    = TOKEN_ATTR_VERIFY_LENGTH
                   | TOKEN_ATTR_VERIFY_BASE64C;

  token.sep[2]     = '.';
  token.len_min[2] = 43;
  token.len_max[2] = 86;
  token.attr[2]    = TOKEN_ATTR_VERIFY_LENGTH
                   | TOKEN_ATTR_VERIFY_BASE64C;

  const int rc_tokenizer = input_tokenizer ((const u8 *) line_buf, line_len, &token);

  if (rc_tokenizer != PARSER_OK) return (rc_tokenizer);

  // header

  const int header_len = token.len[0];

  // payload

  const int payload_len = token.len[1];

  // signature

  const u8 *signature_pos = token.buf[2];
  const int signature_len = token.len[2];

  jwt->signature_len = signature_len;

  // esalt

  const int esalt_len = header_len + 1 + payload_len;

  if (esalt_len > 4096) return (PARSER_SALT_LENGTH);

  memcpy (jwt->salt_buf, line_buf, esalt_len);

  jwt->salt_len = esalt_len;

  // salt
  //
  // Create a hash of the esalt because esalt buffer can change somewhere behind salt->salt_buf size
  // Not a regular MD5 but good enough

  u32 hash[4];

  hash[0] = 0;
  hash[1] = 1;
  hash[2] = 2;
  hash[3] = 3;

  u32 block[16];

  memset (block, 0, sizeof (block));

  for (int i = 0; i < 1024; i += 16)
  {
    for (int j = 0; j < 16; j++)
    {
      block[j] = jwt->salt_buf[i + j];

      md5_transform (block + 0, block + 4, block + 8, block + 12, hash);
    }
  }

  salt->salt_buf[0] = hash[0];
  salt->salt_buf[1] = hash[1];
  salt->salt_buf[2] = hash[2];
  salt->salt_buf[3] = hash[3];

  salt->salt_len = 16;

  // hash

  u8 tmp_buf[100] = { 0 };

  base64_decode (base64url_to_int, signature_pos, signature_len, tmp_buf);

  if (signature_len == 43)
  {
    memcpy (digest_buf, tmp_buf, 32);

    u32 *digest = (u32 *) digest_buf;

    digest[0] = byte_swap_32 (digest[0]);
    digest[1] = byte_swap_32 (digest[1]);
    digest[2] = byte_swap_32 (digest[2]);
    digest[3] = byte_swap_32 (digest[3]);
    digest[4] = byte_swap_32 (digest[4]);
    digest[5] = byte_swap_32 (digest[5]);
    digest[6] = byte_swap_32 (digest[6]);
    digest[7] = byte_swap_32 (digest[7]);
  }
  else if (signature_len == 64)
  {
    memcpy (digest_buf, tmp_buf, 48);

    u64 *digest = (u64 *) digest_buf;

    digest[0] = byte_swap_64 (digest[0]);
    digest[1] = byte_swap_64 (digest[1]);
    digest[2] = byte_swap_64 (digest[2]);
    digest[3] = byte_swap_64 (digest[3]);
    digest[4] = byte_swap_64 (digest[4]);
    digest[5] = byte_swap_64 (digest[5]);
  }
  else if (signature_len == 86)
  {
    memcpy (digest_buf, tmp_buf, 64);

    u64 *digest = (u64 *) digest_buf;

    digest[0] = byte_swap_64 (digest[0]);
    digest[1] = byte_swap_64 (digest[1]);
    digest[2] = byte_swap_64 (digest[2]);
    digest[3] = byte_swap_64 (digest[3]);
    digest[4] = byte_swap_64 (digest[4]);
    digest[5] = byte_swap_64 (digest[5]);
    digest[6] = byte_swap_64 (digest[6]);
    digest[7] = byte_swap_64 (digest[7]);
  }

  return (PARSER_OK);
}

int module_hash_encode (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSED const void *digest_buf, MAYBE_UNUSED const salt_t *salt, MAYBE_UNUSED const void *esalt_buf, MAYBE_UNUSED const void *hook_salt_buf, MAYBE_UNUSED const hashinfo_t *hash_info, char *line_buf, MAYBE_UNUSED const int line_size)
{
  const jwt_t *jwt = (const jwt_t *) esalt_buf;

  const u32 *digest32 = (const u32 *) digest_buf;
  const u64 *digest64 = (const u64 *) digest_buf;

  char tmp_buf[128] = { 0 };

  char ptr_plain[128];

  if (hashconfig->kern_type == KERN_TYPE_JWT_HS256)
  {
    u32 tmp[8];

    tmp[0] = byte_swap_32 (digest32[0]);
    tmp[1] = byte_swap_32 (digest32[1]);
    tmp[2] = byte_swap_32 (digest32[2]);
    tmp[3] = byte_swap_32 (digest32[3]);
    tmp[4] = byte_swap_32 (digest32[4]);
    tmp[5] = byte_swap_32 (digest32[5]);
    tmp[6] = byte_swap_32 (digest32[6]);
    tmp[7] = byte_swap_32 (digest32[7]);

    memcpy (tmp_buf, tmp, 32);

    base64_encode (int_to_base64url, (const u8 *) tmp_buf, 32, (u8 *) ptr_plain);

    ptr_plain[43] = 0;
  }
  else if (hashconfig->kern_type == KERN_TYPE_JWT_HS384)
  {
    u64 tmp[6];

    tmp[0] = byte_swap_64 (digest64[0]);
    tmp[1] = byte_swap_64 (digest64[1]);
    tmp[2] = byte_swap_64 (digest64[2]);
    tmp[3] = byte_swap_64 (digest64[3]);
    tmp[4] = byte_swap_64 (digest64[4]);
    tmp[5] = byte_swap_64 (digest64[5]);

    memcpy (tmp_buf, tmp, 48);

    base64_encode (int_to_base64url, (const u8 *) tmp_buf, 48, (u8 *) ptr_plain);

    ptr_plain[64] = 0;
  }
  else if (hashconfig->kern_type == KERN_TYPE_JWT_HS512)
  {
    u64 tmp[8];

    tmp[0] = byte_swap_64 (digest64[0]);
    tmp[1] = byte_swap_64 (digest64[1]);
    tmp[2] = byte_swap_64 (digest64[2]);
    tmp[3] = byte_swap_64 (digest64[3]);
    tmp[4] = byte_swap_64 (digest64[4]);
    tmp[5] = byte_swap_64 (digest64[5]);
    tmp[6] = byte_swap_64 (digest64[6]);
    tmp[7] = byte_swap_64 (digest64[7]);

    memcpy (tmp_buf, tmp, 64);

    base64_encode (int_to_base64url, (const u8 *) tmp_buf, 64, (u8 *) ptr_plain);

    ptr_plain[86] = 0;
  }

  const int line_len = snprintf (line_buf, line_size, "%s.%s", (char *) jwt->salt_buf, (char *) ptr_plain);

  return line_len;
}

void module_init (module_ctx_t *module_ctx)
{
  module_ctx->module_context_size             = MODULE_CONTEXT_SIZE_CURRENT;
  module_ctx->module_interface_version        = MODULE_INTERFACE_VERSION_CURRENT;

  module_ctx->module_attack_exec              = module_attack_exec;
  module_ctx->module_benchmark_esalt          = module_benchmark_esalt;
  module_ctx->module_benchmark_hook_salt      = MODULE_DEFAULT;
  module_ctx->module_benchmark_mask           = MODULE_DEFAULT;
  module_ctx->module_benchmark_salt           = module_benchmark_salt;
  module_ctx->module_build_plain_postprocess  = MODULE_DEFAULT;
  module_ctx->module_deep_comp_kernel         = MODULE_DEFAULT;
  module_ctx->module_dgst_pos0                = module_dgst_pos0;
  module_ctx->module_dgst_pos1                = module_dgst_pos1;
  module_ctx->module_dgst_pos2                = module_dgst_pos2;
  module_ctx->module_dgst_pos3                = module_dgst_pos3;
  module_ctx->module_dgst_size                = module_dgst_size;
  module_ctx->module_dictstat_disable         = MODULE_DEFAULT;
  module_ctx->module_esalt_size               = module_esalt_size;
  module_ctx->module_extra_buffer_size        = MODULE_DEFAULT;
  module_ctx->module_extra_tmp_size           = MODULE_DEFAULT;
  module_ctx->module_forced_outfile_format    = MODULE_DEFAULT;
  module_ctx->module_hash_binary_count        = MODULE_DEFAULT;
  module_ctx->module_hash_binary_parse        = MODULE_DEFAULT;
  module_ctx->module_hash_binary_save         = MODULE_DEFAULT;
  module_ctx->module_hash_decode_potfile      = MODULE_DEFAULT;
  module_ctx->module_hash_decode_zero_hash    = MODULE_DEFAULT;
  module_ctx->module_hash_decode              = module_hash_decode;
  module_ctx->module_hash_encode_status       = MODULE_DEFAULT;
  module_ctx->module_hash_encode_potfile      = MODULE_DEFAULT;
  module_ctx->module_hash_encode              = module_hash_encode;
  module_ctx->module_hash_init_selftest       = MODULE_DEFAULT;
  module_ctx->module_hash_mode                = MODULE_DEFAULT;
  module_ctx->module_hash_category            = module_hash_category;
  module_ctx->module_hash_name                = module_hash_name;
  module_ctx->module_hashes_count_min         = MODULE_DEFAULT;
  module_ctx->module_hashes_count_max         = MODULE_DEFAULT;
  module_ctx->module_hlfmt_disable            = MODULE_DEFAULT;
  module_ctx->module_hook12                   = MODULE_DEFAULT;
  module_ctx->module_hook23                   = MODULE_DEFAULT;
  module_ctx->module_hook_salt_size           = MODULE_DEFAULT;
  module_ctx->module_hook_size                = MODULE_DEFAULT;
  module_ctx->module_jit_build_options        = MODULE_DEFAULT;
  module_ctx->module_jit_cache_disable        = MODULE_DEFAULT;
  module_ctx->module_kernel_accel_max         = MODULE_DEFAULT;
  module_ctx->module_kernel_accel_min         = MODULE_DEFAULT;
  module_ctx->module_kernel_loops_max         = MODULE_DEFAULT;
  module_ctx->module_kernel_loops_min         = MODULE_DEFAULT;
  module_ctx->module_kernel_threads_max       = MODULE_DEFAULT;
  module_ctx->module_kernel_threads_min       = MODULE_DEFAULT;
  module_ctx->module_kern_type                = module_kern_type;
  module_ctx->module_kern_type_dynamic        = module_kern_type_dynamic;
  module_ctx->module_opti_type                = module_opti_type;
  module_ctx->module_opts_type                = module_opts_type;
  module_ctx->module_outfile_check_disable    = MODULE_DEFAULT;
  module_ctx->module_outfile_check_nocomp     = MODULE_DEFAULT;
  module_ctx->module_potfile_custom_check     = MODULE_DEFAULT;
  module_ctx->module_potfile_disable          = MODULE_DEFAULT;
  module_ctx->module_potfile_keep_all_hashes  = MODULE_DEFAULT;
  module_ctx->module_pwdump_column            = MODULE_DEFAULT;
  module_ctx->module_pw_max                   = MODULE_DEFAULT;
  module_ctx->module_pw_min                   = MODULE_DEFAULT;
  module_ctx->module_salt_max                 = MODULE_DEFAULT;
  module_ctx->module_salt_min                 = MODULE_DEFAULT;
  module_ctx->module_salt_type                = module_salt_type;
  module_ctx->module_separator                = MODULE_DEFAULT;
  module_ctx->module_st_hash                  = module_st_hash;
  module_ctx->module_st_pass                  = module_st_pass;
  module_ctx->module_tmp_size                 = MODULE_DEFAULT;
  module_ctx->module_unstable_warning         = MODULE_DEFAULT;
  module_ctx->module_warmup_disable           = MODULE_DEFAULT;
}
