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| author | Doug Hogan <hogand@users.noreply.github.com> | 2019-01-03 20:17:16 -0800 |
|---|---|---|
| committer | Doug Hogan <hogand@users.noreply.github.com> | 2019-01-08 00:08:22 -0800 |
| commit | 0367ea0bc6953ec81f6d86e2d66e3411348abac9 (patch) | |
| tree | 0e085756db5f82dcd19369d6de856624f23614bb /lib | |
| parent | 05c1ad8eff7ecd61f4e85161033b7cec84d82c1a (diff) | |
| download | otp-0367ea0bc6953ec81f6d86e2d66e3411348abac9.tar.gz otp-0367ea0bc6953ec81f6d86e2d66e3411348abac9.tar.bz2 otp-0367ea0bc6953ec81f6d86e2d66e3411348abac9.zip | |
Revamp block_crypt_nif()
* Simplify error checking.
* Add bounds checking before casting.
* Add error checking for all OpenSSL calls.
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/crypto/c_src/block.c | 104 |
1 files changed, 71 insertions, 33 deletions
diff --git a/lib/crypto/c_src/block.c b/lib/crypto/c_src/block.c index 2ba3290e9f..3399b7b974 100644 --- a/lib/crypto/c_src/block.c +++ b/lib/crypto/c_src/block.c @@ -27,20 +27,27 @@ ERL_NIF_TERM block_crypt_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[] struct cipher_type_t *cipherp = NULL; const EVP_CIPHER *cipher; ErlNifBinary key, ivec, text; - EVP_CIPHER_CTX* ctx; + EVP_CIPHER_CTX *ctx = NULL; ERL_NIF_TERM ret; unsigned char *out; int ivec_size, out_size = 0; + int cipher_len; - if (!enif_inspect_iolist_as_binary(env, argv[1], &key) - || !(cipherp = get_cipher_type(argv[0], key.size)) - || !enif_inspect_iolist_as_binary(env, argv[argc - 2], &text)) { - return enif_make_badarg(env); - } - cipher = cipherp->cipher.p; - if (!cipher) { + if (argc != 4 && argc != 5) + goto bad_arg; + if (!enif_inspect_iolist_as_binary(env, argv[1], &key)) + goto bad_arg; + if (key.size > INT_MAX) + goto bad_arg; + if ((cipherp = get_cipher_type(argv[0], key.size)) == NULL) + goto bad_arg; + if (!enif_inspect_iolist_as_binary(env, argv[argc - 2], &text)) + goto bad_arg; + if (text.size > INT_MAX) + goto bad_arg; + + if ((cipher = cipherp->cipher.p) == NULL) return enif_raise_exception(env, atom_notsup); - } if (argv[0] == atom_aes_cfb8 && (key.size == 24 || key.size == 32)) { @@ -64,42 +71,73 @@ ERL_NIF_TERM block_crypt_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[] argv[0] == atom_des_ecb) ivec_size = 0; /* 0.9.8l returns faulty ivec_size */ #endif + if (ivec_size < 0) + goto bad_arg; - if (text.size % EVP_CIPHER_block_size(cipher) != 0 || - (ivec_size == 0 ? argc != 4 - : (argc != 5 || - !enif_inspect_iolist_as_binary(env, argv[2], &ivec) || - ivec.size != ivec_size))) { - return enif_make_badarg(env); + if ((cipher_len = EVP_CIPHER_block_size(cipher)) < 0) + goto bad_arg; + if (text.size % (size_t)cipher_len != 0) + goto bad_arg; + + if (ivec_size == 0) { + if (argc != 4) + goto bad_arg; + } else { + if (argc != 5) + goto bad_arg; + if (!enif_inspect_iolist_as_binary(env, argv[2], &ivec)) + goto bad_arg; + if (ivec.size != (size_t)ivec_size) + goto bad_arg; } - out = enif_make_new_binary(env, text.size, &ret); + if ((out = enif_make_new_binary(env, text.size, &ret)) == NULL) + goto err; + if ((ctx = EVP_CIPHER_CTX_new()) == NULL) + goto err; - ctx = EVP_CIPHER_CTX_new(); if (!EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, - (argv[argc - 1] == atom_true)) || - !EVP_CIPHER_CTX_set_key_length(ctx, key.size) || - !(EVP_CIPHER_type(cipher) != NID_rc2_cbc || - EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC2_KEY_BITS, key.size * 8, NULL)) || - !EVP_CipherInit_ex(ctx, NULL, NULL, - key.data, ivec_size ? ivec.data : NULL, -1) || - !EVP_CIPHER_CTX_set_padding(ctx, 0)) { + (argv[argc - 1] == atom_true))) + goto err; + if (!EVP_CIPHER_CTX_set_key_length(ctx, (int)key.size)) + goto err; - EVP_CIPHER_CTX_free(ctx); - return enif_raise_exception(env, atom_notsup); + if (EVP_CIPHER_type(cipher) == NID_rc2_cbc) { + if (key.size > INT_MAX / 8) + goto err; + if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC2_KEY_BITS, (int)key.size * 8, NULL)) + goto err; } - if (text.size > 0 && /* OpenSSL 0.9.8h asserts text.size > 0 */ - (!EVP_CipherUpdate(ctx, out, &out_size, text.data, text.size) - || (ASSERT(out_size == text.size), 0) - || !EVP_CipherFinal_ex(ctx, out + out_size, &out_size))) { + if (!EVP_CipherInit_ex(ctx, NULL, NULL, key.data, + ivec_size ? ivec.data : NULL, -1)) + goto err; + if (!EVP_CIPHER_CTX_set_padding(ctx, 0)) + goto err; - EVP_CIPHER_CTX_free(ctx); - return enif_raise_exception(env, atom_notsup); + /* OpenSSL 0.9.8h asserts text.size > 0 */ + if (text.size > 0) { + if (!EVP_CipherUpdate(ctx, out, &out_size, text.data, (int)text.size)) + goto err; + if (ASSERT(out_size == text.size), 0) + goto err; + if (!EVP_CipherFinal_ex(ctx, out + out_size, &out_size)) + goto err; } + ASSERT(out_size == 0); - EVP_CIPHER_CTX_free(ctx); CONSUME_REDS(env, text); + goto done; + bad_arg: + ret = enif_make_badarg(env); + goto done; + + err: + ret = enif_raise_exception(env, atom_notsup); + + done: + if (ctx) + EVP_CIPHER_CTX_free(ctx); return ret; } |