external/boringssl: Sync to 171b54.
This includes the following changes:
https://boringssl.googlesource.com/boringssl/+log/8ca0b4127da11d766067ea6ec4122017ba0edb0e..171b5403ee767fa0f3aecd377867db6533c3eb8f
This also updates the build file to build as C99, so BoringSSL can use
variables in for loops.
Change-Id: I48ae985fd1bed244f7ed327aefc9a13e5b17b185
diff --git a/src/include/openssl/chacha.h b/src/include/openssl/chacha.h
index 64713c2..3d035e6 100644
--- a/src/include/openssl/chacha.h
+++ b/src/include/openssl/chacha.h
@@ -23,8 +23,8 @@
/* CRYPTO_chacha_20 encrypts |in_len| bytes from |in| with the given key and
- * nonce and writes the result to |out|, which may be equal to |in|. The
- * initial block counter is specified by |counter|. */
+ * nonce and writes the result to |out|. If |in| and |out| alias, they must be
+ * equal. The initial block counter is specified by |counter|. */
OPENSSL_EXPORT void CRYPTO_chacha_20(uint8_t *out, const uint8_t *in,
size_t in_len, const uint8_t key[32],
const uint8_t nonce[12], uint32_t counter);