fix tab/space

Cargo.toml

@@ -12,6 +12,7 @@ num_enum = { version = "0.5.1", default-features = false }
 log = "0.4.11"
 generic-array = "0.14.4"
 heapless = "0.5.6"
+asn1_der = { version = "0.7.1", features = [ "native_types", "no_std" ] }
 
 [dependencies.aes-gcm]
 version = "0.8.0"

src/certificate.rs

@@ -0,0 +1,54 @@
+use num_enum::IntoPrimitive;
+use num_enum::TryFromPrimitive;
+
+pub struct Certificate<'a> {
+    tbs_certificate: TBSCertificate<'a>,
+    signature_algorithm: AlgorithmIdentifier<'a>,
+    signature_value: &'a [u8]
+}
+
+pub struct TBSCertificate<'a> {
+    version: Version,
+    serial_number: &'a [u8],
+    signature: AlgorithmIdentifier<'a>,
+    issuer: &'a [u8],
+    validity: Validity<'a>,
+    subject: &'a [u8],
+    subject_public_key_info: SubjectPublicKeyInfo<'a>,
+    issuer_unique_id: Option<&'a [u8]>,
+    subject_unique_id: Option<&'a [u8]>,
+    extensions: Extensions,
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy, IntoPrimitive, TryFromPrimitive)]
+#[repr(u8)]
+pub enum Version {
+    #[num_enum(default)]
+    v1 = 0,
+    v2 = 1,
+    v3 = 2,
+}
+
+pub struct Validity<'a> {
+    not_before: Time<'a>,
+    not_after: Time<'a>,
+}
+
+pub enum Time<'a> {
+    UTCTime(&'a [u8]),
+    GeneralizedTime(&'a [u8]),
+}
+
+pub struct SubjectPublicKeyInfo<'a> {
+    algorithm: AlgorithmIdentifier<'a>,
+    subject_public_key: &'a [u8],
+}
+
+pub struct Extensions {
+    
+}
+
+pub struct AlgorithmIdentifier<'a> {
+    pub algorithm: &'a [u8],
+    pub parameters: &'a [u8],
+}

src/lib.rs

@@ -9,12 +9,15 @@ pub mod parse;
 pub mod buffer;
 pub mod key;
 pub mod session;
+pub mod certificate;
+
+use nom::error::ParseError;
 
 // TODO: Implement errors
 // Details: Encapsulate smoltcp & nom errors
 pub enum Error {
     PropagatedError(smoltcp::Error),
-    ParsingError,
+    ParsingError(nom::error::ErrorKind),
     EncryptionError,
     DecryptionError,
     CapacityError,

src/main.rs

@@ -22,11 +22,10 @@ use hkdf::Hkdf;
 use smoltcp_tls::key::*;
 use smoltcp_tls::buffer::TlsBuffer;
 
-use asn1_der::{
-    DerObject,
-    typed::{ DerEncodable, DerDecodable }
-};
+use smoltcp_tls::certificate::*;
 
+use asn1_der::DerObject;
+use smoltcp_tls::parse::*;
 
 struct CountingRng(u64);
 
@@ -78,14 +77,14 @@ fn main() {
     ).unwrap();
 
 //    tls_socket.tls_connect(&mut sockets).unwrap();
-	let object = DerObject::decode(&CERT).expect("Failed to decode object");
-	println!("raw: {:2X?},\nheader: {:2X?},\ntag: {:2X?},\nvalue: {:2X?}\n",
-		object.raw(),
-		object.header(),
-		object.tag(),
-		object.value()
+    let (rest, result) = parse_asn1_der_certificate(&CERT).unwrap();
+    println!(
+        "{:X?}\n{:X?}\n{:X?}\n{:X?}",
+        rest,
+        result.0,
+        result.1,
+        result.2
     );
-
 }
 
 const CERT: [u8; 805] = [

src/parse.rs

@@ -5,6 +5,7 @@ use nom::bytes::complete::take_till;
 use nom::combinator::complete;
 use nom::sequence::preceded;
 use nom::sequence::tuple;
+use nom::error::make_error;
 use nom::error::ErrorKind;
 use smoltcp::Error;
 use smoltcp::Result;
@@ -12,7 +13,18 @@ use smoltcp::Result;
 use byteorder::{ByteOrder, NetworkEndian, BigEndian};
 
 use crate::tls_packet::*;
+use crate::certificate::Certificate as Asn1DerCertificate;
+use crate::certificate::Version as Asn1DerVersion;
+use crate::certificate::AlgorithmIdentifier as Asn1DerAlgId;
+
 use core::convert::TryFrom;
+use core::convert::TryInto;
+
+use asn1_der::{
+    DerObject,
+    typed::{ DerEncodable, DerDecodable },
+    Asn1DerError,
+};
 
 use alloc::vec::Vec;
 
@@ -327,3 +339,115 @@ fn parse_extension(bytes: &[u8], handshake_type: HandshakeType) -> IResult<&[u8]
         }
     ))
 }
+
+pub fn parse_asn1_der_header(bytes: &[u8]) -> IResult<&[u8], (u8, usize)> {
+    // Parse tag
+    let (rest, tag) = take(1_usize)(bytes)?;
+    // Parse length
+    let (rest, length_byte) = take(1_usize)(rest)?;
+    if length_byte[0] <= 0x7F {
+        Ok((rest, (tag[0], length_byte[0].into())))
+    } else {
+        if length_byte[0] & 0x7F > core::mem::size_of::<usize>().try_into().unwrap() {
+            return Err(nom::Err::Failure((length_byte, ErrorKind::TooLarge)));
+        }
+
+        let length_size = length_byte[0] & 0x7F;
+        let (rem, length_slice) = take(length_size)(rest)?;
+        let mut length_array: [u8; 8] = [0; 8];
+        for array_index in 0..length_slice.len() {
+            length_array[array_index + 8 - length_slice.len()] = length_slice[array_index];
+        }
+        Ok((rem, (tag[0], usize::from_be_bytes(length_array))))
+    }
+}
+
+pub fn parse_asn1_der_object(bytes: &[u8]) -> IResult<&[u8], (u8, usize, &[u8])> {
+    let (rest, (tag, length)) = parse_asn1_der_header(bytes)?;
+    let (rest, value) = take(length)(rest)?;
+    Ok((rest, (tag, length, value)))
+}
+
+pub fn parse_asn1_der_certificate(bytes: &[u8]) -> IResult<&[u8], (&[u8], &[u8], &[u8])> {
+    let (_, (_, _, rest)) = parse_asn1_der_object(bytes)?;
+    let (rest, (_, _, tbscertificate_slice)) = parse_asn1_der_object(rest)?;
+    let (rest, (_, _, signature_alg)) = parse_asn1_der_object(rest)?;
+    let (rest, (_, _, sig_val)) = parse_asn1_der_object(rest)?;
+    Ok((rest, (tbscertificate_slice, signature_alg, sig_val)))
+}
+
+pub fn parse_asn1_der_tbs_certificate(bytes: &[u8]) -> IResult<&[u8], Vec<&[u8]>> {
+    todo!()
+}
+
+// version: [0] EXPLICIT Version DEFAULT V1
+// Version encapsulates an Integer
+// i.e. context-specific, constructed, type [0] -> tag: A0
+pub fn parse_asn1_der_version(bytes: &[u8]) -> IResult<&[u8], Asn1DerVersion> {
+    let (rest, (tag_val, length, value)) = parse_asn1_der_object(bytes)?;
+    // Verify the tag is indeed 0xA0
+    if tag_val != 0xA0 {
+        return Err(nom::Err::Failure((&[], ErrorKind::Verify)));
+    }
+    // Parse the encapsulated INTEGER, force completeness
+    let (_, integer) = complete(parse_asn1_der_integer)(value)?;
+    // Either 0, 1, or 2, take the last byte and assert all former bytes to be 0
+    let (zeroes, version_byte) = take(integer.len()-1)(integer)?;
+    complete(take_till(|byte| byte != 0))(zeroes)?;
+    Ok((rest, Asn1DerVersion::try_from(version_byte[0]).unwrap()))
+}
+
+// INTEGER: tag: 0x02
+pub fn parse_asn1_der_integer(bytes: &[u8]) -> IResult<&[u8], &[u8]> {
+    let (rest, (tag_val, length, value)) = parse_asn1_der_object(bytes)?;
+    // Verify the tag is indeed 0x02
+    if tag_val != 0x02 {
+        return Err(nom::Err::Failure((&[], ErrorKind::Verify)));
+    }
+    Ok((rest, value))
+}
+
+// CertificateSerialNumber: alias of INTEGER
+pub fn parse_asn1_der_serial_number(bytes: &[u8]) -> IResult<&[u8], &[u8]> {
+    parse_asn1_der_integer(bytes)
+}
+
+// Algorithm Identifier: Sequence -> universal, constructed, 0 (0x30)
+// Encapsulates OID (alg) and optional params (params)
+pub fn parse_asn1_der_algorithm_identifier(bytes: &[u8]) -> IResult<&[u8], Asn1DerAlgId> {
+    let (rest, (tag_val, length, value)) = parse_asn1_der_object(bytes)?;
+    // Verify the tag_val is indeed 0x30
+    if tag_val != 0x30 {
+        return Err(nom::Err::Failure((&[], ErrorKind::Verify)));
+    }
+    // Parse OID and then optionl parameters
+    let (_, (oid, (_, _, optional_param))) = complete(
+        tuple((
+            parse_asn1_der_oid,
+            parse_asn1_der_object
+        ))
+    )(value)?;
+    Ok((
+        rest,
+        Asn1DerAlgId {
+            algorithm: oid,
+            parameters: optional_param,
+        }
+    ))
+}
+
+// Parser for Universal OID type (0x06)
+pub fn parse_asn1_der_oid(bytes: &[u8]) -> IResult<&[u8], &[u8]> {
+    let (rest, (tag_val, length, value)) = parse_asn1_der_object(bytes)?;
+    // Verify the tag_val is indeed 0x06
+    if tag_val != 0x06 {
+        return Err(nom::Err::Failure((&[], ErrorKind::Verify)));
+    }
+    Ok((rest, value))
+}
+
+// Parser for Time Validity Structure
+pub fn parse_asn1_der_validity(bytes: &[u8]) -> IResult<&[u8], &[u8]> {
+    let (rest, (tag_val, length, value)) = parse_asn1_der_object(bytes)?;
+    
+}