/* TODO(3.0) Figure out what flags need to be passed */
#define WRAP_FLAGS (EVP_CIPH_WRAP_MODE | EVP_CIPH_CUSTOM_IV \
| EVP_CIPH_ALWAYS_CALL_INIT)
+#define WRAP_FLAGS_INV (WRAP_FLAGS | EVP_CIPH_FLAG_INVERSE_CIPHER)
typedef size_t (*aeswrap_fn)(void *key, const unsigned char *iv,
unsigned char *out, const unsigned char *in,
return 0;
ctx->enc = enc;
- ctx->block = enc ? (block128_f)AES_encrypt : (block128_f)AES_decrypt;
if (ctx->pad)
wctx->wrapfn = enc ? CRYPTO_128_wrap_pad : CRYPTO_128_unwrap_pad;
else
return 0;
}
if (key != NULL) {
+ int use_forward_transform;
+
if (keylen != ctx->keylen) {
ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
return 0;
}
- if (ctx->enc)
- AES_set_encrypt_key(key, keylen * 8, &wctx->ks.ks);
+ /*
+ * See SP800-38F : Section 5.1
+ * The forward and inverse transformations for the AES block
+ * cipher—called “cipher” and “inverse cipher” are informally known as
+ * the AES encryption and AES decryption functions, respectively.
+ * If the designated cipher function for a key-wrap algorithm is chosen
+ * to be the AES decryption function, then CIPH-1K will be the AES
+ * encryption function.
+ */
+ if ((ctx->flags & EVP_CIPH_FLAG_INVERSE_CIPHER) == 0)
+ use_forward_transform = ctx->enc;
else
+ use_forward_transform = !ctx->enc;
+ if (use_forward_transform) {
+ AES_set_encrypt_key(key, keylen * 8, &wctx->ks.ks);
+ ctx->block = (block128_f)AES_encrypt;
+ } else {
AES_set_decrypt_key(key, keylen * 8, &wctx->ks.ks);
+ ctx->block = (block128_f)AES_decrypt;
+ }
}
return 1;
}
IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_PAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_PAD_IVLEN * 8);
IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_PAD_IVLEN * 8);
+
+IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 256, 64, AES_WRAP_NOPAD_IVLEN * 8);
+IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 192, 64, AES_WRAP_NOPAD_IVLEN * 8);
+IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 128, 64, AES_WRAP_NOPAD_IVLEN * 8);
+IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 256, 64, AES_WRAP_PAD_IVLEN * 8);
+IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 192, 64, AES_WRAP_PAD_IVLEN * 8);
+IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 128, 64, AES_WRAP_PAD_IVLEN * 8);