reapack

commit c681457f2b0968180c05421588397a4ec45abd15
parent db203e9508242bfe3272e2e6989934d9b56979c9
Author: cfillion <cfillion@users.noreply.github.com>
Date:   Fri,  7 Dec 2018 21:50:11 -0500

implement simple hash algorithm detection from string

Diffstat:
M
src/hash.cpp
 | 
18
++++++++++++++++++
M
src/hash.hpp
 | 
4
++++
M
test/hash.cpp
 | 
18
++++++++++++++++++

3 files changed, 40 insertions(+), 0 deletions(-)
diff --git a/src/hash.cpp b/src/hash.cpp
@@ -173,3 +173,21 @@ const std::string &Hash::digest()
 
   return m_value;
 }
+
+bool Hash::getAlgorithm(const std::string &hash, Algorithm *out)
+{
+  unsigned int algo, size;
+  if(sscanf(hash.c_str(), "%2x%2x", &algo, &size) != 2)
+    return false;
+
+  if(hash.size() != size + 4)
+    return false;
+
+  switch(algo) {
+  case SHA256:
+    *out = static_cast<Algorithm>(algo);
+    return true;
+  default:
+    return false;
+  };
+}
diff --git a/src/hash.hpp b/src/hash.hpp
@@ -10,7 +10,11 @@ public:
     SHA256 = 0x12,
   };
 
+  static bool getAlgorithm(const std::string &hash, Algorithm *out);
+
   Hash(Algorithm);
+  Hash(const Hash &) = delete;
+
   void write(const char *data, size_t len);
   const std::string &digest();
 
diff --git a/test/hash.cpp b/test/hash.cpp
@@ -33,3 +33,21 @@ TEST_CASE("invalid algorithm", M) {
   hash.write("foo bar", 7);
   REQUIRE(hash.digest() == "");
 }
+
+TEST_CASE("get hash algorithm", M) {
+  Hash::Algorithm algo;
+
+  SECTION("empty string")
+    REQUIRE_FALSE(Hash::getAlgorithm("", &algo));
+
+  SECTION("only sha-256 ID")
+    REQUIRE_FALSE(Hash::getAlgorithm("12", &algo));
+
+  SECTION("unexpected size")
+    REQUIRE_FALSE(Hash::getAlgorithm("1204ab", &algo));
+
+  SECTION("seemingly good (but not actually) sha-256") {
+    REQUIRE(Hash::getAlgorithm("1204abcd", &algo));
+    REQUIRE(algo == Hash::SHA256);
+  }
+}