daemon: Support SHA-512 hashes.

Fixes #679.

Note: on x86_64, SHA-512 is considerably faster than SHA-256 (198 MB/s
versus 131 MB/s).

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

daemon.am

@@ -69,7 +69,8 @@ libutil_headers =				\
   nix/libutil/gcrypt-hash.hh			\
   nix/libutil/md5.h				\
   nix/libutil/sha1.h				\
-  nix/libutil/sha256.h
+  nix/libutil/sha256.h				\
+  nix/libutil/sha512.h
 
 libutil_a_CPPFLAGS =				\
   -I$(top_builddir)/nix				\

nix/libutil/hash.cc

@@ -11,6 +11,7 @@ extern "C" {
 #include "md5.h"
 #include "sha1.h"
 #include "sha256.h"
+#include "sha512.h"
 }
 #endif
 
@@ -40,6 +41,7 @@ Hash::Hash(HashType type)
     if (type == htMD5) hashSize = md5HashSize;
     else if (type == htSHA1) hashSize = sha1HashSize;
     else if (type == htSHA256) hashSize = sha256HashSize;
+    else if (type == htSHA512) hashSize = sha512HashSize;
     else throw Error("unknown hash type");
     assert(hashSize <= maxHashSize);
     memset(hash, 0, maxHashSize);
@@ -199,6 +201,7 @@ struct Ctx
     MD5_CTX md5;
     SHA_CTX sha1;
     SHA256_CTX sha256;
+    SHA512_CTX sha512;
 };
 
 
@@ -207,6 +210,7 @@ static void start(HashType ht, Ctx & ctx)
     if (ht == htMD5) MD5_Init(&ctx.md5);
     else if (ht == htSHA1) SHA1_Init(&ctx.sha1);
     else if (ht == htSHA256) SHA256_Init(&ctx.sha256);
+    else if (ht == htSHA512) SHA512_Init(&ctx.sha512);
 }
 
 
@@ -216,6 +220,7 @@ static void update(HashType ht, Ctx & ctx,
     if (ht == htMD5) MD5_Update(&ctx.md5, bytes, len);
     else if (ht == htSHA1) SHA1_Update(&ctx.sha1, bytes, len);
     else if (ht == htSHA256) SHA256_Update(&ctx.sha256, bytes, len);
+    else if (ht == htSHA512) SHA512_Update(&ctx.sha512, bytes, len);
 }
 
 
@@ -224,6 +229,7 @@ static void finish(HashType ht, Ctx & ctx, unsigned char * hash)
     if (ht == htMD5) MD5_Final(hash, &ctx.md5);
     else if (ht == htSHA1) SHA1_Final(hash, &ctx.sha1);
     else if (ht == htSHA256) SHA256_Final(hash, &ctx.sha256);
+    else if (ht == htSHA512) SHA512_Final(hash, &ctx.sha512);
 }
 
 
@@ -321,6 +327,7 @@ HashType parseHashType(const string & s)
     if (s == "md5") return htMD5;
     else if (s == "sha1") return htSHA1;
     else if (s == "sha256") return htSHA256;
+    else if (s == "sha512") return htSHA512;
     else return htUnknown;
 }
 
@@ -330,6 +337,7 @@ string printHashType(HashType ht)
     if (ht == htMD5) return "md5";
     else if (ht == htSHA1) return "sha1";
     else if (ht == htSHA256) return "sha256";
+    else if (ht == htSHA512) return "sha512";
     else throw Error("cannot print unknown hash type");
 }
 

nix/libutil/hash.hh

@@ -7,19 +7,20 @@
 namespace nix {
 
 
-typedef enum { htUnknown, htMD5, htSHA1, htSHA256 } HashType;
+typedef enum { htUnknown, htMD5, htSHA1, htSHA256, htSHA512 } HashType;
 
 
 const int md5HashSize = 16;
 const int sha1HashSize = 20;
 const int sha256HashSize = 32;
+const int sha512HashSize = 64;
 
 extern const string base32Chars;
 
 
 struct Hash
 {
-    static const unsigned int maxHashSize = 32;
+    static const unsigned int maxHashSize = 64;
     unsigned int hashSize;
     unsigned char hash[maxHashSize];
 

nix/libutil/sha512.h

@@ -0,0 +1,35 @@
+/* GNU Guix --- Functional package management for GNU
+   Copyright (C) 2012, 2015 Ludovic Courtès <ludo@gnu.org>
+
+   This file is part of GNU Guix.
+
+   GNU Guix is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or (at
+   your option) any later version.
+
+   GNU Guix is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <gcrypt-hash.hh>
+
+#define SHA512_CTX guix_hash_context
+
+static inline void
+SHA512_Init (struct SHA512_CTX *ctx)
+{
+  guix_hash_init (ctx, GCRY_MD_SHA512);
+}
+
+#define SHA512_Update guix_hash_update
+
+static inline void
+SHA512_Final (void *resbuf, struct SHA512_CTX *ctx)
+{
+  guix_hash_final (resbuf, ctx, GCRY_MD_SHA512);
+}