PhcFormatHasher

const PhcFormatHasher = struct

File

Code

const PhcFormatHasher = struct {
    const BinValue = phc_format.BinValue;

    const HashResult = struct {
        alg_id: []const u8,
        alg_version: ?u32,
        m: u32,
        t: u32,
        p: u24,
        salt: BinValue(max_salt_len),
        hash: BinValue(max_hash_len),
    };

    pub fn create(
        allocator: mem.Allocator,
        password: []const u8,
        params: Params,
        mode: Mode,
        buf: []u8,
        io: Io,
    ) HasherError![]const u8 {
        if (params.secret != null or params.ad != null) return HasherError.InvalidEncoding;

        var salt: [default_salt_len]u8 = undefined;
        io.random(&salt);

        var hash: [default_hash_len]u8 = undefined;
        try kdf(allocator, &hash, password, &salt, params, mode, io);

        return phc_format.serialize(HashResult{
            .alg_id = @tagName(mode),
            .alg_version = version,
            .m = params.m,
            .t = params.t,
            .p = params.p,
            .salt = try BinValue(max_salt_len).fromSlice(&salt),
            .hash = try BinValue(max_hash_len).fromSlice(&hash),
        }, buf);
    }

    pub fn verify(
        allocator: mem.Allocator,
        str: []const u8,
        password: []const u8,
        io: Io,
    ) HasherError!void {
        const hash_result = try phc_format.deserialize(HashResult, str);

        const mode = std.meta.stringToEnum(Mode, hash_result.alg_id) orelse
            return HasherError.PasswordVerificationFailed;
        if (hash_result.alg_version) |v| {
            if (v != version) return HasherError.InvalidEncoding;
        }
        const params = Params{ .t = hash_result.t, .m = hash_result.m, .p = hash_result.p };

        const expected_hash = hash_result.hash.constSlice();
        var hash_buf: [max_hash_len]u8 = undefined;
        if (expected_hash.len > hash_buf.len) return HasherError.InvalidEncoding;
        const hash = hash_buf[0..expected_hash.len];

        try kdf(allocator, hash, password, hash_result.salt.constSlice(), params, mode, io);
        if (!mem.eql(u8, hash, expected_hash)) return HasherError.PasswordVerificationFailed;
    }
}