1 files changed, 52 insertions, 0 deletions
diff --git a/third_party/bearssl/src/rsa_ssl_decrypt.c b/third_party/bearssl/src/rsa_ssl_decrypt.c
new file mode 100644
index 0000000..047eb18
--- /dev/null
+++ b/third_party/bearssl/src/rsa_ssl_decrypt.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <[email protected]>
+ *
+ * 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"
+
+/* see bearssl_rsa.h */
+uint32_t
+br_rsa_ssl_decrypt(br_rsa_private core, const br_rsa_private_key *sk,
+	unsigned char *data, size_t len)
+{
+	uint32_t x;
+	size_t u;
+
+	/*
+	 * A first check on length. Since this test works only on the
+	 * buffer length, it needs not (and cannot) be constant-time.
+	 */
+	if (len < 59 || len != (sk->n_bitlen + 7) >> 3) {
+		return 0;
+	}
+	x = core(data, sk);
+
+	x &= EQ(data[0], 0x00);
+	x &= EQ(data[1], 0x02);
+	for (u = 2; u < (len - 49); u ++) {
+		x &= NEQ(data[u], 0);
+	}
+	x &= EQ(data[len - 49], 0x00);
+	memmove(data, data + len - 48, 48);
+	return x;
+}