use HashStringList in the acquire system

It is not very extensible to have the supported Hashes hardcoded
everywhere and especially if it is part of virtual method names.
It is also possible that a method does not support the 'best' hash
(yet), so we might end up not being able to verify a file even though we
have a common subset of supported hashes. And those are just two of the
cases in which it is handy to have a more dynamic selection.

The downside is that this is a MAJOR API break, but the HashStringList
has a string constructor for compatibility, so with a bit of luck the
few frontends playing with the acquire system directly are okay.

1 files changed, 22 insertions, 4 deletions

diff --git a/apt-pkg/pkgrecords.h b/apt-pkg/pkgrecords.h
index b5237b3a0..b0b449ae1 100644
--- a/apt-pkg/pkgrecords.h
+++ b/apt-pkg/pkgrecords.h
@@ -18,6 +18,8 @@
 #define PKGLIB_PKGRECORDS_H
 
 #include <apt-pkg/pkgcache.h>
+#include <apt-pkg/hashes.h>
+#include <apt-pkg/macros.h>
 
 #include <string>
 #include <vector>
@@ -56,13 +58,21 @@ class pkgRecords::Parser						/*{{{*/
    
    // These refer to the archive file for the Version
    virtual std::string FileName() {return std::string();};
-   virtual std::string MD5Hash() {return std::string();};
-   virtual std::string SHA1Hash() {return std::string();};
-   virtual std::string SHA256Hash() {return std::string();};
-   virtual std::string SHA512Hash() {return std::string();};
    virtual std::string SourcePkg() {return std::string();};
    virtual std::string SourceVer() {return std::string();};
 
+   /** return all known hashes in this record.
+    *
+    * For authentication proposes packages come with hashsums which
+    * this method is supposed to parse and return so that clients can
+    * choose the hash to be used.
+    */
+   virtual HashStringList Hashes() const { return HashStringList(); };
+   APT_DEPRECATED std::string MD5Hash() const { return GetHashFromHashes("MD5Sum"); };
+   APT_DEPRECATED std::string SHA1Hash() const { return GetHashFromHashes("SHA1"); };
+   APT_DEPRECATED std::string SHA256Hash() const { return GetHashFromHashes("SHA256"); };
+   APT_DEPRECATED std::string SHA512Hash() const { return GetHashFromHashes("SHA512"); };
+
    // These are some general stats about the package
    virtual std::string Maintainer() {return std::string();};
    virtual std::string ShortDesc() {return std::string();};
@@ -77,6 +87,14 @@ class pkgRecords::Parser						/*{{{*/
    virtual void GetRec(const char *&Start,const char *&Stop) {Start = Stop = 0;};
    
    virtual ~Parser() {};
+
+   private:
+   APT_HIDDEN std::string GetHashFromHashes(char const * const type) const
+   {
+      HashStringList const hashes = Hashes();
+      HashString const * const hs = hashes.find(type);
+      return hs != NULL ? hs->HashValue() : "";
+   };
 };
 									/*}}}*/
 #endif