5 files changed, 396 insertions, 0 deletions

diff --git a/src/datatypes.rs b/src/datatypes.rs
new file mode 100644
index 0000000..7712064
--- /dev/null
+++ b/src/datatypes.rs
@@ -0,0 +1,116 @@
+use crate::result::ArchiveResult;
+use std::io::{Read, Write};
+
+pub trait ArchiveDatatype
+where
+    Self: Sized,
+{
+    const SIZE: usize;
+
+    fn read(reader: impl Read) -> ArchiveResult<Self>;
+
+    fn write(&self, writer: impl Write) -> ArchiveResult<()>;
+}
+
+pub mod utils {
+    pub fn read_string(buf: &[u8]) -> String {
+        String::from_utf8(buf.into()).unwrap()
+    }
+
+    pub fn write_string(string: &str) -> &[u8] {
+        string.as_bytes()
+    }
+
+    pub fn vec(vec: &[u8]) -> &[u8] {
+        vec
+    }
+
+    #[macro_export]
+    macro_rules! create_archive_datatype {
+        {
+            $vis:vis struct $struct_name:ident {
+                $($field:ident: $field_type:ty,)*
+            }
+
+            $(
+                let $custom_field:ident: $custom_field_type:ty {
+                    size: $custom_field_size: expr,
+                    read: $custom_field_read: path,
+                    write: $custom_field_write: path,
+                }
+            )*
+
+            $(
+                const {
+                    $($const_name:ident: $const_type:ty = $const_value:expr;)+
+                }
+            )?
+
+            $(
+                read $read_code:block
+            )?
+
+            $(
+                write $write_code:block
+            )?
+        }
+        => {
+            #[derive(Debug)]
+            $vis struct $struct_name {
+                $($vis $field: $field_type),*,
+                $($vis $custom_field: $custom_field_type),*
+            }
+
+            $(
+                impl $struct_name {
+                    $(const $const_name: $const_type = $const_value;)*
+                }
+            )?
+
+            impl ArchiveDatatype for $struct_name {
+                const SIZE: usize = ($((<$field_type>::BITS / 8)+)*0) as usize;
+
+                fn read(mut reader: impl Read) -> ArchiveResult<Self> {
+                    let mut buf = [0; Self::SIZE];
+                    reader.read(&mut buf)?;
+
+                    $(
+                        let (bytes, buf) = buf.split_at((<$field_type>::BITS / 8) as usize);
+                        let $field = <$field_type>::from_le_bytes(bytes.try_into().unwrap());
+                    )*
+
+                    $(
+                        let $custom_field = {
+                            let mut buf = vec![0; $custom_field_size as usize];
+                            reader.read(&mut buf)?;
+                            $custom_field_read(&buf).into()
+                        };
+                    )*
+
+                    #[allow(dropping_references)]
+                    drop(buf);
+
+                    $($read_code;)?
+
+                    Ok(
+                        Self {
+                            $($field),*,
+                            $($custom_field),*
+                        }
+                    )
+                }
+
+                fn write(&self, mut writer: impl Write) -> ArchiveResult<()> {
+                    $($write_code;)?
+                    writer.write(&[
+                        $(&self.$field.to_le_bytes()[..]),*,
+                        $(&$custom_field_write(&self.$custom_field)),*
+                    ].concat())?;
+                    Ok(())
+                }
+            }
+        };
+    }
+
+    pub use create_archive_datatype;
+}
diff --git a/src/lib.rs b/src/lib.rs
index 163f760..abfd599 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,6 +3,7 @@ pub mod zip;
 mod result;
 
 mod archive;
+mod datatypes;
 mod file;
 mod io;
 
diff --git a/src/result.rs b/src/result.rs
index 47302ae..715f10c 100644
--- a/src/result.rs
+++ b/src/result.rs
@@ -7,6 +7,7 @@ pub type ArchiveResult<R> = Result<R, ArchiveError>;
 #[derive(Debug)]
 pub enum ArchiveError {
     IO(io::Error),
+    WrongSignature { expected: u32, received: u32 },
 }
 
 impl From<io::Error> for ArchiveError {
@@ -19,6 +20,12 @@ impl Display for ArchiveError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             Self::IO(err) => write!(f, "{err}"),
+            Self::WrongSignature { expected, received } => {
+                write!(
+                    f,
+                    "Wrong signature. Expected: {expected}, received: {received}"
+                )
+            }
         }
     }
 }
@@ -27,6 +34,7 @@ impl Error for ArchiveError {
     fn source(&self) -> Option<&(dyn Error + 'static)> {
         match self {
             Self::IO(source) => Some(source),
+            _ => None,
         }
     }
 }
diff --git a/src/zip/datatypes.rs b/src/zip/datatypes.rs
new file mode 100644
index 0000000..b280e5d
--- /dev/null
+++ b/src/zip/datatypes.rs
@@ -0,0 +1,270 @@
+use crate::datatypes::{utils, ArchiveDatatype};
+use crate::result::{ArchiveError, ArchiveResult};
+use std::io::{Read, Write};
+
+utils::create_archive_datatype! {
+    pub struct LocalFileHeader {
+        signature: u32,
+        version_needed: u16,
+        general_purpose_bit_flag: u16,
+        compression_method: u16,
+        last_mod_file_time: u16,
+        last_mod_file_date: u16,
+        crc32: u32,
+        compressed_size: u32,
+        uncompressed_size: u32,
+        file_name_length: u16,
+        extra_field_length: u16,
+    }
+
+    let file_name: String {
+        size: file_name_length,
+        read: utils::read_string,
+        write: utils::write_string,
+    }
+
+    let extra_field: Vec<u8> {
+        size: file_name_length,
+        read: utils::vec,
+        write: utils::vec,
+    }
+
+    const {
+        SIGNATURE: u32 = 0x04034b50;
+    }
+
+    read {
+        if signature != Self::SIGNATURE {
+            return Err(ArchiveError::WrongSignature { expected: Self::SIGNATURE, received: signature })
+        }
+    }
+}
+
+pub struct DataDescriptor {
+    pub signature: Option<u32>,
+    pub crc32: u32,
+    pub compressed_size: u32,
+    pub uncompressed_size: u32,
+}
+
+impl DataDescriptor {
+    const SIGNATURE: u32 = 0x04034b50;
+}
+
+impl ArchiveDatatype for DataDescriptor {
+    const SIZE: usize = 12;
+
+    fn read(mut reader: impl Read) -> ArchiveResult<Self> {
+        let mut buf = [0; Self::SIZE];
+        reader.read(&mut buf)?;
+
+        let signature = u32::from_le_bytes([buf[0], buf[1], buf[2], buf[3]]);
+        if signature == Self::SIGNATURE {
+            return Ok(Self {
+                signature: Some(signature),
+                crc32: u32::from_le_bytes([buf[4], buf[5], buf[6], buf[7]]),
+                compressed_size: u32::from_le_bytes([buf[8], buf[9], buf[10], buf[11]]),
+                uncompressed_size: {
+                    let mut buf = [0; 4];
+                    reader.read(&mut buf)?;
+                    u32::from_le_bytes([buf[0], buf[1], buf[2], buf[3]])
+                },
+            });
+        } else {
+            return Ok(Self {
+                signature: None,
+                crc32: signature,
+                compressed_size: u32::from_le_bytes([buf[4], buf[5], buf[6], buf[7]]),
+                uncompressed_size: u32::from_le_bytes([buf[8], buf[9], buf[10], buf[11]]),
+            });
+        }
+    }
+
+    fn write(&self, mut writer: impl Write) -> ArchiveResult<()> {
+        writer.write(
+            &[
+                Self::SIGNATURE.to_le_bytes(),
+                self.crc32.to_le_bytes(),
+                self.compressed_size.to_le_bytes(),
+                self.uncompressed_size.to_le_bytes(),
+            ]
+            .concat(),
+        )?;
+        Ok(())
+    }
+}
+
+utils::create_archive_datatype! {
+    pub struct ArchiveExtraDataRecord {
+        signature: u32,
+        extra_field_length: u32,
+    }
+
+    let extra_field: Vec<u8> {
+        size: extra_field_length,
+        read: utils::vec,
+        write: utils::vec,
+    }
+
+    const {
+        SIGNATURE: u32 = 0x08064b50;
+    }
+
+    read {
+        if signature != Self::SIGNATURE {
+            return Err(ArchiveError::WrongSignature { expected: Self::SIGNATURE, received: signature })
+        }
+    }
+}
+
+utils::create_archive_datatype! {
+    pub struct CentralDirectoryRecord {
+        signature: u32,
+        version_made_by: u16,
+        version_needed: u16,
+        general_purpose_bit_flag: u16,
+        compression_method: u16,
+        last_mod_file_time: u16,
+        last_mod_file_date: u16,
+        crc32: u32,
+        compressed_size: u32,
+        uncompressed_size: u32,
+        file_name_length: u16,
+        extra_field_length: u16,
+        file_comment_length: u16,
+        disk_number: u16,
+        internal_file_attributes: u16,
+        external_file_attributes: u32,
+        relative_header_offset: u32,
+    }
+
+    let file_name: String {
+        size: file_name_length,
+        read: utils::read_string,
+        write: utils::write_string,
+    }
+
+    let extra_field: Vec<u8> {
+        size: external_file_attributes,
+        read: utils::vec,
+        write: utils::vec,
+    }
+
+    let file_comment: String {
+        size: file_comment_length,
+        read: utils::read_string,
+        write: utils::write_string,
+    }
+
+    const {
+        SIGNATURE: u32 = 0x02014b50;
+    }
+
+    read {
+        if signature != Self::SIGNATURE {
+            return Err(ArchiveError::WrongSignature { expected: Self::SIGNATURE, received: signature })
+        }
+    }
+}
+
+utils::create_archive_datatype! {
+    pub struct DigitalSignature{
+        signature: u32,
+        data_size: u16,
+    }
+
+    let data: Vec<u8> {
+        size: data_size,
+        read: utils::vec,
+        write: utils::vec,
+    }
+
+    const {
+        SIGNATURE: u32 = 0x05054b50;
+    }
+
+    read {
+        if signature != Self::SIGNATURE {
+            return Err(ArchiveError::WrongSignature { expected: Self::SIGNATURE, received: signature })
+        }
+    }
+}
+
+utils::create_archive_datatype! {
+    pub struct Zip64EndOfCentralDirectoryRecord {
+        signature: u32,
+        size_of_struct: u64,
+        version_made_by: u16,
+        version_needed: u16,
+        disk_number: u32,
+        disk_number_where_starts_central_directory: u32,
+        entries_in_central_directory_on_disk: u64,
+        entries_in_central_directory: u64,
+        size_of_central_directory_records: u64,
+        offset_of_central_directory_entries: u64,
+    }
+
+    let extensible_data: Vec<u8> {
+        size: size_of_struct - Self::SIZE as u64 + 12,
+        read: utils::vec,
+        write: utils::vec,
+    }
+
+    const {
+        SIGNATURE: u32 = 0x08064b50;
+    }
+
+    read {
+        if signature != Self::SIGNATURE {
+            return Err(ArchiveError::WrongSignature { expected: Self::SIGNATURE, received: signature })
+        }
+    }
+}
+
+utils::create_archive_datatype! {
+    pub struct Zip64EndOfCentralDirectoryLocator {
+        signature: u32,
+        disk_number_where_starts_zip64_eocd: u32,
+        relative_offset_of_zip64_eocd: u64,
+        total_disks_number: u32,
+    }
+
+    const {
+        SIGNATURE: u32 = 0x07064b50;
+    }
+
+    read {
+        if signature != Self::SIGNATURE {
+            return Err(ArchiveError::WrongSignature { expected: Self::SIGNATURE, received: signature })
+        }
+    }
+}
+
+utils::create_archive_datatype! {
+    pub struct EndOfCentralDirectoryRecord {
+        signature: u32,
+        disk_number: u16,
+        disk_number_where_starts_central_directory: u16,
+        entries_in_central_directory_on_disk: u16,
+        entries_in_central_directory: u16,
+        size_of_central_directory_records: u32,
+        offset_of_central_directory_entries: u32,
+        comment_length: u16,
+    }
+
+    let comment: String {
+        size: comment_length,
+        read: utils::read_string,
+        write: utils::write_string,
+    }
+
+    const {
+        SIGNATURE: u32 = 0x06054b50;
+    }
+
+    read {
+        if signature != Self::SIGNATURE {
+            return Err(ArchiveError::WrongSignature { expected: Self::SIGNATURE, received: signature })
+        }
+    }
+}
diff --git a/src/zip/mod.rs b/src/zip/mod.rs
index 5241c87..b668b6b 100644
--- a/src/zip/mod.rs
+++ b/src/zip/mod.rs
@@ -1,4 +1,5 @@
 mod archive;
+mod datatypes;
 mod file;
 mod io;