Added RSA/OAEP implementation.

[BearSSL] / src / rsa / rsa_i62_oaep_decrypt.c

diff --git a/src/rsa/rsa_i62_oaep_decrypt.c b/src/rsa/rsa_i62_oaep_decrypt.c
new file mode 100644 (file)
index 0000000..38470dd
--- /dev/null
+++ b/src/rsa/rsa_i62_oaep_decrypt.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+#if BR_INT128 || BR_UMUL128
+
+/* see bearssl_rsa.h */
+uint32_t
+br_rsa_i62_oaep_decrypt(const br_hash_class *dig,
+       const void *label, size_t label_len,
+       const br_rsa_private_key *sk, void *data, size_t *len)
+{
+       uint32_t r;
+
+       if (*len != ((sk->n_bitlen + 7) >> 3)) {
+               return 0;
+       }
+       r = br_rsa_i62_private(data, sk);
+       r &= br_rsa_oaep_unpad(dig, label, label_len, data, len);
+       return r;
+}
+
+/* see bearssl_rsa.h */
+br_rsa_oaep_decrypt
+br_rsa_i62_oaep_decrypt_get(void)
+{
+       return &br_rsa_i62_oaep_decrypt;
+}
+
+#else
+
+/* see bearssl_rsa.h */
+br_rsa_oaep_decrypt
+br_rsa_i62_oaep_decrypt_get(void)
+{
+       return 0;
+}
+
+#endif