remove hash.zig

fix

src/install.zig

@@ -1,7 +1,6 @@
 const std = @import("std");
 const builtin = @import("builtin");
 const config = @import("config.zig");
-const hash = @import("hash.zig");
 const download = @import("download.zig");
 const architecture = @import("architecture.zig");
 const tools = @import("tools.zig");
@@ -116,7 +115,7 @@ pub fn from_version(version: []const u8) !void {
         if (data.shasum) |actual_shasum| {
             const computed_hash = try download.content(allocator, data.name, data.tarball.?);
             if (computed_hash) |shasum| {
-                if (!hash.verify_hash(shasum, actual_shasum)) {
+                if (!tools.verify_hash(shasum, actual_shasum)) {
                     return error.HashMismatch;
                 }
             }

src/tools.zig

@@ -1,6 +1,8 @@
 const std = @import("std");
 const builtin = @import("builtin");
 
+const testing = std.testing;
+
 var allocator: std.mem.Allocator = undefined;
 var home_dir: []const u8 = undefined;
 
@@ -47,3 +49,40 @@ pub fn get_zvm_path_segment(tmp_allocator: std.mem.Allocator, segment: []const u
         &[_][]const u8{ get_home(), ".zm", segment },
     );
 }
+
+/// for verify hash
+pub fn verify_hash(computed_hash: [32]u8, actual_hash_string: []const u8) bool {
+    if (actual_hash_string.len != 64) return false; // SHA256 hash should be 64 hex characters
+
+    var actual_hash_bytes: [32]u8 = undefined;
+    var i: usize = 0;
+
+    for (actual_hash_string) |char| {
+        const byte = switch (char) {
+            '0'...'9' => char - '0',
+            'a'...'f' => char - 'a' + 10,
+            'A'...'F' => char - 'A' + 10,
+            else => return false, // Invalid character in hash string
+        };
+
+        if (i % 2 == 0) {
+            actual_hash_bytes[i / 2] = byte << 4;
+        } else {
+            actual_hash_bytes[i / 2] |= byte;
+        }
+
+        i += 1;
+    }
+
+    return std.mem.eql(u8, computed_hash[0..], actual_hash_bytes[0..]);
+}
+
+test "verify_hash basic test" {
+    const sample_hash: [32]u8 = [_]u8{ 0x33, 0x9a, 0x89, 0xdc, 0x08, 0x73, 0x6b, 0x84, 0xc4, 0x75, 0x2b, 0x3d, 0xed, 0xdc, 0x0f, 0x2c, 0x71, 0xb5, 0x0b, 0x66, 0xa2, 0x68, 0x5f, 0x26, 0x77, 0x9c, 0xbb, 0xac, 0x46, 0x11, 0x1b, 0x68 };
+
+    var sample_hash_hex: [64]u8 = undefined;
+    _ = std.fmt.bufPrint(&sample_hash_hex, "{}", .{std.fmt.fmtSliceHexLower(sample_hash[0..])}) catch unreachable;
+
+    try testing.expect(verify_hash(sample_hash, &sample_hash_hex));
+    try testing.expect(!verify_hash(sample_hash, "incorrect_hash"));
+}