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).

2 files changed, 10 insertions, 2 deletions

diff --git a/src/libutil/hash.cc b/src/libutil/hash.cc
index 8a83ed67fe..2d97c5e6b6 100644
--- a/src/libutil/hash.cc
+++ b/src/libutil/hash.cc
@@ -32,6 +32,7 @@ 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);
@@ -190,6 +191,7 @@ union Ctx
     MD5_CTX md5;
     SHA_CTX sha1;
     SHA256_CTX sha256;
+    SHA512_CTX sha512;
 };
 
 
@@ -198,6 +200,7 @@ 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);
 }
 
 
@@ -207,6 +210,7 @@ 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);
 }
 
 
@@ -215,6 +219,7 @@ 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);
 }
 
 
@@ -312,6 +317,7 @@ 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;
 }
 
@@ -321,6 +327,7 @@ 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");
 }
 
diff --git a/src/libutil/hash.hh b/src/libutil/hash.hh
index 2c6f176ec7..841b4cb293 100644
--- a/src/libutil/hash.hh
+++ b/src/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];