int32_t mz_crypt_hmac_init(void *handle, const void *key, int32_t key_length)
{
mz_crypt_hmac *hmac = (mz_crypt_hmac *)handle;
int32_t result = 0;
const EVP_MD *evp_md = NULL;
if (hmac == NULL || key == NULL)
return MZ_PARAM_ERROR;
mz_crypt_hmac_reset(handle);
hmac->ctx = HMAC_CTX_new();
if (hmac->algorithm == MZ_HASH_SHA1)
evp_md = EVP_sha1();
else
evp_md = EVP_sha256();
result = HMAC_Init(hmac->ctx, key, key_length, evp_md);
if (!result)
{
hmac->error = ERR_get_error();
return MZ_HASH_ERROR;
}
return MZ_OK;
}
int32_t mz_crypt_hmac_init(void *handle, const void *key, int32_t key_length)
{
mz_crypt_hmac *hmac = (mz_crypt_hmac *)handle;
CCHmacAlgorithm algorithm = 0;
if (hmac == NULL || key == NULL)
return MZ_PARAM_ERROR;
mz_crypt_hmac_reset(handle);
if (hmac->algorithm == MZ_HASH_SHA1)
algorithm = kCCHmacAlgSHA1;
else if (hmac->algorithm == MZ_HASH_SHA256)
algorithm = kCCHmacAlgSHA256;
else
return MZ_PARAM_ERROR;
CCHmacInit(&hmac->ctx, algorithm, key, key_length);
return MZ_OK;
}
int32_t mz_stream_wzaes_open(void *stream, const char *path, int32_t mode)
{
mz_stream_wzaes *wzaes = (mz_stream_wzaes *)stream;
uint16_t salt_length = 0;
uint16_t password_length = 0;
uint16_t key_length = 0;
uint8_t kbuf[2 * MZ_AES_KEY_LENGTH_MAX + MZ_AES_PW_VERIFY_SIZE];
uint8_t verify[MZ_AES_PW_VERIFY_SIZE];
uint8_t verify_expected[MZ_AES_PW_VERIFY_SIZE];
uint8_t salt_value[MZ_AES_SALT_LENGTH_MAX];
const char *password = path;
wzaes->total_in = 0;
wzaes->total_out = 0;
wzaes->initialized = 0;
if (mz_stream_is_open(wzaes->stream.base) != MZ_OK)
return MZ_OPEN_ERROR;
if (password == NULL)
password = wzaes->password;
if (password == NULL)
return MZ_PARAM_ERROR;
password_length = (uint16_t)strlen(password);
if (password_length > MZ_AES_PW_LENGTH_MAX)
return MZ_PARAM_ERROR;
if (wzaes->encryption_mode < 1 || wzaes->encryption_mode > 3)
return MZ_PARAM_ERROR;
salt_length = MZ_AES_SALT_LENGTH(wzaes->encryption_mode);
if (mode & MZ_OPEN_MODE_WRITE)
{
#ifdef MZ_ZIP_NO_COMPRESSION
return MZ_SUPPORT_ERROR;
#else
mz_crypt_rand(salt_value, salt_length);
#endif
}
else if (mode & MZ_OPEN_MODE_READ)
{
#ifdef MZ_ZIP_NO_DECOMPRESSION
return MZ_SUPPORT_ERROR;
#else
if (mz_stream_read(wzaes->stream.base, salt_value, salt_length) != salt_length)
return MZ_READ_ERROR;
#endif
}
key_length = MZ_AES_KEY_LENGTH(wzaes->encryption_mode);
/* Derive the encryption and authentication keys and the password verifier */
mz_crypt_pbkdf2((uint8_t *)password, password_length, salt_value, salt_length,
MZ_AES_KEYING_ITERATIONS, kbuf, 2 * key_length + MZ_AES_PW_VERIFY_SIZE);
/* Initialize the encryption nonce and buffer pos */
wzaes->crypt_pos = MZ_AES_BLOCK_SIZE;
memset(wzaes->nonce, 0, sizeof(wzaes->nonce));
/* Initialize for encryption using key 1 */
mz_crypt_aes_reset(wzaes->aes);
mz_crypt_aes_set_mode(wzaes->aes, wzaes->encryption_mode);
mz_crypt_aes_set_encrypt_key(wzaes->aes, kbuf, key_length);
/* Initialize for authentication using key 2 */
mz_crypt_hmac_reset(wzaes->hmac);
mz_crypt_hmac_set_algorithm(wzaes->hmac, MZ_HASH_SHA1);
mz_crypt_hmac_init(wzaes->hmac, kbuf + key_length, key_length);
memcpy(verify, kbuf + (2 * key_length), MZ_AES_PW_VERIFY_SIZE);
if (mode & MZ_OPEN_MODE_WRITE)
{
if (mz_stream_write(wzaes->stream.base, salt_value, salt_length) != salt_length)
return MZ_WRITE_ERROR;
wzaes->total_out += salt_length;
if (mz_stream_write(wzaes->stream.base, verify, MZ_AES_PW_VERIFY_SIZE) != MZ_AES_PW_VERIFY_SIZE)
return MZ_WRITE_ERROR;
wzaes->total_out += MZ_AES_PW_VERIFY_SIZE;
}
else if (mode & MZ_OPEN_MODE_READ)
{
wzaes->total_in += salt_length;
if (mz_stream_read(wzaes->stream.base, verify_expected, MZ_AES_PW_VERIFY_SIZE) != MZ_AES_PW_VERIFY_SIZE)
return MZ_READ_ERROR;
wzaes->total_in += MZ_AES_PW_VERIFY_SIZE;
if (memcmp(verify_expected, verify, MZ_AES_PW_VERIFY_SIZE) != 0)
return MZ_PASSWORD_ERROR;
}
wzaes->mode = mode;
wzaes->initialized = 1;
return MZ_OK;
}
