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-rw-r--r--third_party/bearssl/src/i15_encode.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/third_party/bearssl/src/i15_encode.c b/third_party/bearssl/src/i15_encode.c
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+++ b/third_party/bearssl/src/i15_encode.c
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+/*
+ * Copyright (c) 2017 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 inner.h */
+void
+br_i15_encode(void *dst, size_t len, const uint16_t *x)
+{
+	unsigned char *buf;
+	size_t u, xlen;
+	uint32_t acc;
+	int acc_len;
+
+	xlen = (x[0] + 15) >> 4;
+	if (xlen == 0) {
+		memset(dst, 0, len);
+		return;
+	}
+	u = 1;
+	acc = 0;
+	acc_len = 0;
+	buf = dst;
+	while (len -- > 0) {
+		if (acc_len < 8) {
+			if (u <= xlen) {
+				acc += (uint32_t)x[u ++] << acc_len;
+			}
+			acc_len += 15;
+		}
+		buf[len] = (unsigned char)acc;
+		acc >>= 8;
+		acc_len -= 8;
+	}
+}