wip: no-std

Author: ibotty

md5-crypt/Cargo.toml

@@ -25,8 +25,8 @@ md-5 = { version = "0.10.5", default-features = false }
 
 [features]
 default = ["simple"]
-simple = ["rand", "std", "subtle"]
-std = []
+alloc = []
+simple = ["alloc", "rand", "subtle"]
 
 [package.metadata.docs.rs]
 all-features = true

md5-crypt/src/b64.rs

@@ -1,36 +1,32 @@
 //! Base64 encoding support
 
 use crate::defs::{BLOCK_SIZE, MAP_MD5, PW_SIZE_MD5};
-use alloc::vec::Vec;
-use base64ct::{Base64ShaCrypt, Encoding};
-
-#[cfg(feature = "simple")]
+#[cfg(any(feature = "subtle", test))]
 use crate::errors::DecodeError;
+use base64ct::{Base64ShaCrypt, Encoding};
 
-pub fn encode_md5(source: &[u8]) -> Vec<u8> {
+pub fn encode_md5(source: &[u8]) -> [u8; PW_SIZE_MD5] {
     let mut transposed = [0u8; BLOCK_SIZE];
     for (i, &ti) in MAP_MD5.iter().enumerate() {
         transposed[i] = source[ti as usize];
     }
     let mut buf = [0u8; PW_SIZE_MD5];
     Base64ShaCrypt::encode(&transposed, &mut buf).unwrap();
-    buf.to_vec()
+    buf
 }
 
-#[cfg(feature = "simple")]
-pub fn decode_md5(source: &[u8]) -> Result<Vec<u8>, DecodeError> {
+#[cfg(any(feature = "subtle", test))]
+pub fn decode_md5(source: &[u8]) -> Result<[u8; BLOCK_SIZE], DecodeError> {
     let mut buf = [0u8; PW_SIZE_MD5];
     Base64ShaCrypt::decode(source, &mut buf).map_err(|_| DecodeError)?;
-
     let mut transposed = [0u8; BLOCK_SIZE];
     for (i, &ti) in MAP_MD5.iter().enumerate() {
         transposed[ti as usize] = buf[i];
     }
-    Ok(transposed.to_vec())
+    Ok(transposed)
 }
 
 mod tests {
-    #[cfg(feature = "simple")]
     #[test]
     fn test_encode_decode_md5() {
         let original: [u8; 16] = [

md5-crypt/src/defs.rs

@@ -5,7 +5,6 @@ pub const BLOCK_SIZE: usize = 16;
 pub const PW_SIZE_MD5: usize = 22;
 
 /// Maximum length of a salt
-#[cfg(feature = "simple")]
 pub const SALT_MAX_LEN: usize = 8;
 
 /// Encoding table.

md5-crypt/src/errors.rs

@@ -1,59 +1,42 @@
 //! Error types.
 
+#[cfg(feature = "alloc")]
 use alloc::string;
 
-#[cfg(feature = "simple")]
-use alloc::string::String;
-
-#[cfg(feature = "std")]
-use std::io;
-
 /// Error type.
 #[derive(Debug)]
 pub enum CryptError {
     /// RNG failed.
     RandomError,
 
-    /// I/O error.
-    #[cfg(feature = "std")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
-    IoError(io::Error),
-
     /// UTF-8 error.
+    #[cfg(feature = "alloc")]
     StringError(string::FromUtf8Error),
 }
 
-#[cfg(feature = "std")]
-impl From<io::Error> for CryptError {
-    fn from(e: io::Error) -> Self {
-        CryptError::IoError(e)
-    }
-}
-
+#[cfg(feature = "alloc")]
 impl From<string::FromUtf8Error> for CryptError {
     fn from(e: string::FromUtf8Error) -> Self {
         CryptError::StringError(e)
     }
 }
 
-#[cfg(feature = "simple")]
-#[cfg_attr(docsrs, doc(cfg(feature = "simple")))]
 #[derive(Debug)]
 pub enum CheckError {
-    InvalidFormat(String),
+    InvalidFormat(&'static str),
+    #[cfg(feature = "subtle")]
     Crypt(CryptError),
+    #[cfg(feature = "subtle")]
     HashMismatch,
 }
 
 /// Decoding errors.
-#[cfg(feature = "simple")]
 #[cfg_attr(docsrs, doc(cfg(feature = "simple")))]
 #[derive(Debug)]
 pub struct DecodeError;
 
-#[cfg(feature = "simple")]
 impl From<DecodeError> for CheckError {
     fn from(_: DecodeError) -> CheckError {
-        CheckError::InvalidFormat("invalid B64".into())
+        CheckError::InvalidFormat("invalid B64")
     }
 }

md5-crypt/src/lib.rs

@@ -33,34 +33,31 @@
 #![warn(missing_docs, rust_2018_idioms)]
 
 // TODO(tarcieri): heapless support
-#[macro_use]
+#[cfg(feature = "alloc")]
 extern crate alloc;
 
-#[cfg(feature = "std")]
-extern crate std;
-
 mod b64;
 mod defs;
 mod errors;
 
-pub use crate::{defs::BLOCK_SIZE, errors::CryptError};
+pub use crate::{
+    defs::{BLOCK_SIZE, PW_SIZE_MD5, SALT_MAX_LEN},
+    errors::CryptError,
+};
 
-use alloc::string::String;
 use md5::{Digest, Md5};
 
+#[cfg(feature = "subtle")]
+use crate::errors::CheckError;
+
 #[cfg(feature = "simple")]
 use {
-    crate::{
-        defs::{SALT_MAX_LEN, TAB},
-        errors::CheckError,
-    },
-    alloc::string::ToString,
+    crate::defs::TAB,
+    alloc::string::String,
     rand::{distributions::Distribution, thread_rng, Rng},
 };
 
-#[cfg(feature = "simple")]
 static MD5_SALT_PREFIX: &str = "$1$";
-#[cfg(feature = "simple")]
 
 /// The MD5 crypt function returned as byte vector
 ///
@@ -160,10 +157,9 @@ pub fn md5_crypt(password: &[u8], salt: &[u8]) -> Result<[u8; BLOCK_SIZE], Crypt
 /// # Returns
 /// - `Ok(())` if calculation was successful
 /// - `Err(errors::CryptError)` otherwise
-pub fn md5_crypt_b64(password: &[u8], salt: &[u8]) -> Result<String, CryptError> {
+pub fn md5_crypt_b64(password: &[u8], salt: &[u8]) -> Result<[u8; PW_SIZE_MD5], CryptError> {
     let output = md5_crypt(password, salt)?;
-    let r = String::from_utf8(b64::encode_md5(&output))?;
-    Ok(r)
+    Ok(b64::encode_md5(&output))
 }
 
 /// Simple interface for generating a MD5 password hash.
@@ -191,7 +187,7 @@ pub fn md5_simple(password: &str) -> Result<String, CryptError> {
     result.push_str(MD5_SALT_PREFIX);
     result.push_str(&salt);
     result.push('$');
-    let s = String::from_utf8(b64::encode_md5(&out))?;
+    let s = String::from_utf8(b64::encode_md5(&out).to_vec())?;
     result.push_str(&s);
     Ok(result)
 }
@@ -206,40 +202,35 @@ pub fn md5_simple(password: &str) -> Result<String, CryptError> {
 /// # Return
 /// `OK(())` if password matches otherwise Err(CheckError) in case of invalid
 /// format or password mismatch.
-#[cfg(feature = "simple")]
+#[cfg(feature = "subtle")]
 #[cfg_attr(docsrs, doc(cfg(feature = "simple")))]
 pub fn md5_check(password: &str, hashed_value: &str) -> Result<(), CheckError> {
     let mut iter = hashed_value.split('$');
 
     // Check that there are no characters before the first "$"
     if iter.next() != Some("") {
-        return Err(CheckError::InvalidFormat(
-            "Should start with '$".to_string(),
-        ));
+        return Err(CheckError::InvalidFormat("Should start with '$"));
     }
 
     if iter.next() != Some("1") {
-        return Err(CheckError::InvalidFormat(format!(
-            "does not contain MD5 identifier: '{}'",
-            MD5_SALT_PREFIX
-        )));
+        return Err(CheckError::InvalidFormat(
+            "does not contain MD5 identifier: '$1$'",
+        ));
     }
 
-    let next = iter.next().ok_or_else(|| {
-        CheckError::InvalidFormat("Does not contain a salt or hash string".to_string())
-    })?;
+    let next = iter.next().ok_or(CheckError::InvalidFormat(
+        "Does not contain a salt or hash string",
+    ))?;
 
     let salt = next;
 
     let hash = iter
         .next()
-        .ok_or_else(|| CheckError::InvalidFormat("Does not contain a hash string".to_string()))?;
+        .ok_or(CheckError::InvalidFormat("Does not contain a hash string"))?;
 
     // Make sure there is no trailing data after the final "$"
     if iter.next().is_some() {
-        return Err(CheckError::InvalidFormat(
-            "Trailing characters present".to_string(),
-        ));
+        return Err(CheckError::InvalidFormat("Trailing characters present"));
     }
 
     let output = md5_crypt(password.as_bytes(), salt.as_bytes()).map_err(CheckError::Crypt)?;

md5-crypt/tests/lib.rs

@@ -3,6 +3,8 @@ use md5_crypt::md5_crypt_b64;
 #[cfg(feature = "simple")]
 use md5_crypt::{md5_check, md5_simple};
 
+use std::str;
+
 struct TestVector {
     input: &'static str,
     salt: &'static str,
@@ -76,7 +78,8 @@ const TEST_VECTORS: &[TestVector] = &[
 #[test]
 fn test_md5_crypt() {
     for t in TEST_VECTORS {
-        let result = md5_crypt_b64(t.input.as_bytes(), t.salt.as_bytes()).unwrap();
+        let result_array = md5_crypt_b64(t.input.as_bytes(), t.salt.as_bytes()).unwrap();
+        let result = str::from_utf8(&result_array).unwrap();
         assert!(result == t.result);
     }
 }