X-Git-Url: https://bearssl.org/gitweb//home/git/?p=BearSSL;a=blobdiff_plain;f=src%2Fint%2Fi15_decode.c;fp=src%2Fec%2Fec_prime_i31_secp521r1.c;h=fc2c0be0d0be93705fb22c605436c9dd7d046eb3;hp=84d7d54f4679e7c579c5635154fb4a1e7a1c7599;hb=2f454aad577ae53798935cc32438a2d3f02ba31f;hpb=bd3036844bd20b2b8d7bce7fee5ad010ce401915;ds=inline

diff --git a/src/ec/ec_prime_i31_secp521r1.c b/src/int/i15_decode.c
similarity index 63%
rename from src/ec/ec_prime_i31_secp521r1.c
rename to src/int/i15_decode.c
index 84d7d54..fc2c0be 100644
--- a/src/ec/ec_prime_i31_secp521r1.c
+++ b/src/int/i15_decode.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ * Copyright (c) 2017 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
@@ -24,27 +24,33 @@
 
 #include "inner.h"
 
-static const uint32_t P521_P[] = {
-	0x00000219,
-	0x7FFFFFFF, 0x7FFFFFFF, 0x7FFFFFFF, 0x7FFFFFFF,
-	0x7FFFFFFF, 0x7FFFFFFF, 0x7FFFFFFF, 0x7FFFFFFF,
-	0x7FFFFFFF, 0x7FFFFFFF, 0x7FFFFFFF, 0x7FFFFFFF,
-	0x7FFFFFFF, 0x7FFFFFFF, 0x7FFFFFFF, 0x7FFFFFFF,
-	0x01FFFFFF
-};
+/* see inner.h */
+void
+br_i15_decode(uint16_t *x, const void *src, size_t len)
+{
+	const unsigned char *buf;
+	size_t v;
+	uint32_t acc;
+	int acc_len;
 
-static const uint32_t P521_B[] = {
-	0x00000219,
-	0x540FC00A, 0x228FEA35, 0x2C34F1EF, 0x67BF107A,
-	0x46FC1CD5, 0x1605E9DD, 0x6937B165, 0x272A3D8F,
-	0x42785586, 0x44C8C778, 0x15F3B8B4, 0x64B73366,
-	0x03BA8B69, 0x0D05B42A, 0x21F929A2, 0x2C31C393,
-	0x00654FAE
-};
+	buf = src;
+	v = 1;
+	acc = 0;
+	acc_len = 0;
+	while (len -- > 0) {
+		uint32_t b;
 
-/* see inner.h */
-const br_ec_prime_i31_curve br_ec_prime_i31_secp521r1 = {
-	P521_P,
-	P521_B,
-	0x00000001
-};
+		b = buf[len];
+		acc |= (b << acc_len);
+		acc_len += 8;
+		if (acc_len >= 15) {
+			x[v ++] = acc & 0x7FFF;
+			acc_len -= 15;
+			acc >>= 15;
+		}
+	}
+	if (acc_len != 0) {
+		x[v ++] = acc;
+	}
+	x[0] = br_i15_bit_length(x + 1, v - 1);
+}