Some cleanups (removed unused files, split i15 code into per-function files).

[BearSSL] / src / int / i15_decode.c

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 (file)
--- 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);
+}