Add documentation for CRYPTO_memcmp.

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/9225)

diff --git a/doc/man3/CRYPTO_memcmp.pod b/doc/man3/CRYPTO_memcmp.pod
new file mode 100644 (file)
index 0000000..9182d00
--- /dev/null
+++ b/doc/man3/CRYPTO_memcmp.pod
@@ -0,0 +1,39 @@
+=pod
+
+=head1 NAME
+
+CRYPTO_memcmp - Constant time memory comparison
+
+=head1 SYNOPSIS
+
+ #include <openssl/crypto.h>
+
+ int CRYPTO_memcmp(const void *a, const void *b, size_t len);
+
+=head1 DESCRIPTION
+
+The CRYPTO_memcmp function compares the B<len> bytes pointed to by B<a> and B<b>
+for equality.
+It takes an amount of time dependent on B<len>, but independent of the
+contents of the memory regions pointed to by B<a> and B<b>.
+
+=head1 RETURN VALUES
+
+CRYPTO_memcmp() returns 0 if the memory regions are equal and non-zero
+otherwise.
+
+=head1 NOTES
+
+Unlike memcmp(2), this function cannot be used to order the two memory regions
+as the return value when they differ is undefined, other than being non-zero.
+
+=head1 COPYRIGHT
+
+Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the Apache License 2.0 (the "License").  You may not use
+this file except in compliance with the License.  You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut

diff --git a/util/missingcrypto.txt b/util/missingcrypto.txt
index 30b1e2dda2e46b387747784773710a1c91ae1cbf..0dc4379a69e92ccf099b265b19a162de13224526 100644 (file)
--- a/util/missingcrypto.txt
+++ b/util/missingcrypto.txt
@@ -300,7 +300,6 @@ CRYPTO_gcm128_tag
 CRYPTO_mem_debug_free
 CRYPTO_mem_debug_malloc
 CRYPTO_mem_debug_realloc
-CRYPTO_memcmp
 CRYPTO_memdup
 CRYPTO_nistcts128_decrypt
 CRYPTO_nistcts128_decrypt_block

diff --git a/util/missingcrypto111.txt b/util/missingcrypto111.txt
index 0b223afebd9e054f7eecda43e74b38a56f781a39..1fb924bc700c09c074eb88658965a0b46469798c 100644 (file)
--- a/util/missingcrypto111.txt
+++ b/util/missingcrypto111.txt
@@ -317,7 +317,6 @@ CRYPTO_gcm128_tag
 CRYPTO_mem_debug_free
 CRYPTO_mem_debug_malloc
 CRYPTO_mem_debug_realloc
-CRYPTO_memcmp
 CRYPTO_memdup
 CRYPTO_nistcts128_decrypt
 CRYPTO_nistcts128_decrypt_block