file_checksum: sys backend

Author: scivision

+stdlib/+dotnet/file_checksum.m

@@ -0,0 +1,27 @@
+%% DOTNET.FILE_CHECKSUM compute checksum has of file
+
+% Ref: https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/security/MessageDigest.html#getInstance(java.lang.String)
+
+function hash = file_checksum(file, hash_method)
+
+if any(strcmp(hash_method, {'sha256', 'SHA256'}))
+  hash_method = "SHA-256";
+end
+
+file_chunk = 10e6;  % arbitrary (bytes) didn't seem to be very sensitive for speed
+
+fid = fopen(file, 'r');
+assert(fid > 1, "could not open file %s", file)
+
+inst = System.Security.Cryptography.HashAlgorithm.Create(hash_method);
+while ~feof(fid)
+  % https://docs.microsoft.com/en-us/dotnet/api/system.security.cryptography.hashalgorithm.computehash
+  inst.ComputeHash(fread(fid, file_chunk, '*uint8'));
+end
+h = uint8(inst.Hash);
+
+fclose(fid);
+
+hash = sprintf('%.2x', h);
+
+end

+stdlib/+java/file_checksum.m

@@ -0,0 +1,27 @@
+%% JAVA.FILE_CHECKSUM compute checksum hash of file
+% Ref: https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/security/MessageDigest.html#getInstance(java.lang.String)
+
+function hash = file_checksum(file, hash_method)
+
+if any(strcmp(hash_method, {'sha256', 'SHA256'}))
+  hash_method = "SHA-256";
+end
+
+file_chunk = 10e6;  % arbitrary (bytes) didn't seem to be very sensitive for speed
+
+fid = fopen(file, 'r');
+assert(fid > 1, "could not open file %s", file)
+
+inst = javaMethod("getInstance", "java.security.MessageDigest", hash_method);
+while ~feof(fid)
+  % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/security/MessageDigest.html#update(byte)
+  inst.update(fread(fid, file_chunk, '*uint8'));
+end
+% https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/security/MessageDigest.html#digest()
+h = typecast(inst.digest, 'uint8');
+
+fclose(fid);
+
+hash = sprintf('%.2x', h);
+
+end

+stdlib/+sys/file_checksum.m

@@ -0,0 +1,37 @@
+%% SYS.FILE_CHECKSUM compute checksum of file
+function hash = file_checksum(file, hash_method)
+
+switch lower(hash_method)
+  case {"sha-256", "sha256"}
+    if ismac()
+      cmd = "shasum --algorithm 256 --binary " + file;
+    elseif ispc()
+      cmd = "CertUtil -hashfile " + file + " SHA256";
+    else
+      cmd = "sha256sum --binary " + file;
+    end
+  case "md5"
+    if ismac()
+      cmd = "md5 -r " + file;
+    elseif ispc()
+      cmd = "CertUtil -hashfile " + file + " MD5";
+    else
+      cmd = "md5sum " + file;
+    end
+  otherwise, error('unhandled hash method %s', hash_method)
+end
+
+[s, m] = system(cmd);
+
+assert(s == 0, "failed to compute SHA256 hash of %s: %s", file, m)
+
+switch lower(hash_method)
+  case {"sha-256", "sha256"}
+    hash = regexp(m, '^\w{64}','match','once','lineanchors');
+    assert(strlength(hash)==64, 'SHA256 hash is 64 characters')
+  case "md5"
+    hash = regexp(m, '^\w{32}','match','once','lineanchors');
+    assert(strlength(hash)==32, 'MD5 hash is 32 characters')
+end
+
+end

+stdlib/file_checksum.m

@@ -10,46 +10,15 @@
 %
 % Ref: https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/security/MessageDigest.html#getInstance(java.lang.String)
 
-function hash = file_checksum(file, method)
+function hash = file_checksum(file, hash_method, backend)
 arguments
   file {mustBeTextScalar}
-  method {mustBeTextScalar}
+  hash_method {mustBeTextScalar}
+  backend (1,:) string = ["java", "dotnet", "sys"]
 end
 
-if any(strcmp(method, {'sha256', 'SHA256'}))
-  method = "SHA-256";
-end
-
-file_chunk = 10e6;  % arbitrary (bytes) didn't seem to be very sensitive for speed
-
-fid = fopen(file, 'r');
-assert(fid > 1, "could not open file %s", file)
-
-if stdlib.has_dotnet()
-
-  inst = System.Security.Cryptography.HashAlgorithm.Create(method);
-  while ~feof(fid)
-    % https://docs.microsoft.com/en-us/dotnet/api/system.security.cryptography.hashalgorithm.computehash
-    inst.ComputeHash(fread(fid, file_chunk, '*uint8'));
-  end
-  h = uint8(inst.Hash);
-
-elseif stdlib.has_java()
-
-  inst = javaMethod("getInstance", "java.security.MessageDigest", method);
-  while ~feof(fid)
-    % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/security/MessageDigest.html#update(byte)
-    inst.update(fread(fid, file_chunk, '*uint8'));
-  end
-  % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/security/MessageDigest.html#digest()
-  h = typecast(inst.digest, 'uint8');
-
-else
-  error('no supported hash method found, please install .NET or Java')
-end
-
-fclose(fid);
+fun = choose_method(backend, "file_checksum");
 
-hash = sprintf('%.2x', h);
+hash = fun(file, hash_method);
 
 end

archive/md5sum.m

@@ -7,6 +7,7 @@
 properties (TestParameter)
 Ph = {{'md5', '5d41402abc4b2a76b9719d911017c592'}, ...
       {'sha-256', '2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824'}}
+backend = {'java', 'dotnet', 'sys'}
 end
 
 methods(TestClassSetup)
@@ -39,8 +40,7 @@ function remove_temp_wd(tc)
 
 methods (Test)
 
-function test_hash_text(tc, Ph)
-tc.assumeTrue(stdlib.has_dotnet() || stdlib.has_java())
+function test_hash_text(tc, Ph, backend)
 
 fn = tc.td + "/hello";
 fid = fopen(fn, "w");
@@ -51,7 +51,7 @@ function test_hash_text(tc, Ph)
 
 tc.assertThat(fn, matlab.unittest.constraints.IsFile)
 
-tc.verifyEqual(stdlib.file_checksum(fn, Ph{1}), Ph{2})
+tc.verifyEqual(stdlib.file_checksum(fn, Ph{1}, backend), Ph{2})
 
 switch Ph{1}
   case 'md5', tc.verifyEqual(stdlib.md5sum(fn), Ph{2})