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-rw-r--r--src/codec.rs40
-rw-r--r--src/jpeg/segment.rs42
-rw-r--r--src/lossless/lsb.rs65
3 files changed, 55 insertions, 92 deletions
diff --git a/src/codec.rs b/src/codec.rs
index 8b38a9b..11fa76e 100644
--- a/src/codec.rs
+++ b/src/codec.rs
@@ -1,26 +1,28 @@
+use thiserror::Error;
+
/// Codecs enable the concealment of payload data inside the data of a carrier.
pub trait Codec {
- /// Data type representing the carrier.
- type Carrier;
-
- /// Data type representing the payload.
- type Payload;
-
- /// Data type representing encoder output/decoder input (usually the same as the carrier).
- type Output;
-
- /// Type of errors produced by this codec.
- type Error;
-
/// Embeds payload data inside carrier, returning the result.
- fn encode<C, P>(&self, carrier: C, payload: P) -> Result<Self::Output, Self::Error>
- where
- C: Into<Self::Carrier>,
- P: Into<Self::Payload>;
+ fn encode(&self, carrier: &[u8], payload: &[u8]) -> Result<Vec<u8>, CodecError>;
/// Extracts payload data from an encoded carrier, returning the carrier with data removed and the
/// payload data.
- fn decode<E>(&self, encoded: E) -> Result<(Self::Carrier, Self::Payload), Self::Error>
- where
- E: Into<Self::Output>;
+ fn decode(&self, encoded: &[u8]) -> Result<(Vec<u8>, Vec<u8>), CodecError>;
+}
+
+/// Errors produced by a codec
+#[derive(Debug, Error)]
+pub enum CodecError {
+ /// Variant used when data is determined not to be encoded. Note that a codec may have no way
+ /// of knowing this, so this may not be returned even if the data was not encoded
+ #[error("Data was not encoded with this codec")]
+ DataNotEncoded,
+
+ /// Variant used when data is invalid in some way. Allows a message string for further context
+ #[error("Provided data invalid: {0}")]
+ DataInvalid(String),
+
+ /// Variant used when some dependency, such as a file load, fails
+ #[error("Error occured in dependency: {0}")]
+ DependencyError(String),
}
diff --git a/src/jpeg/segment.rs b/src/jpeg/segment.rs
index b20ba3b..cd1a651 100644
--- a/src/jpeg/segment.rs
+++ b/src/jpeg/segment.rs
@@ -1,9 +1,8 @@
use std::{mem::size_of, usize};
use img_parts::jpeg::{markers, Jpeg, JpegSegment};
-use thiserror::Error;
-use crate::codec::Codec;
+use crate::{codec::Codec, CodecError};
/// Codec for storing payload data in JPEG comment (COM) segments. Can store an arbitrary amount of
/// data, as long as the number of comment segments does not exceed u64::MAX.
@@ -14,21 +13,13 @@ pub struct JpegSegmentCodec {
}
impl Codec for JpegSegmentCodec {
- type Carrier = Vec<u8>;
- type Payload = Vec<u8>;
- type Output = Self::Carrier;
- type Error = JpegSegmentError;
-
- fn encode<C, P>(&self, carrier: C, payload: P) -> Result<Self::Output, Self::Error>
- where
- C: Into<Self::Carrier>,
- P: Into<Self::Payload>,
+ fn encode(&self, carrier: &[u8], payload: &[u8]) -> Result<Vec<u8>, CodecError>
{
- let mut jpeg = match Jpeg::from_bytes(carrier.into().into()) {
- Ok(image) => image,
- Err(err) => return Err(JpegSegmentError::ParseFailed { inner: err })
+ let mut jpeg = match Jpeg::from_bytes(carrier.to_vec().into()) {
+ Ok(v) => v,
+ Err(e) => return Err(CodecError::DependencyError(e.to_string()))
};
- let mut payload_bytes: Self::Carrier = payload.into();
+ let mut payload_bytes = payload.to_vec();
let segment_count = ((payload_bytes.len() + size_of::<u64>()) as u64).div_ceil((u16::MAX as usize - size_of::<u16>()) as u64);
payload_bytes.splice(0..0, segment_count.to_le_bytes());
for (index, payload_chunk) in payload_bytes.chunks(u16::MAX as usize - size_of::<u16>()).enumerate() {
@@ -38,13 +29,11 @@ impl Codec for JpegSegmentCodec {
Ok(jpeg.encoder().bytes().to_vec())
}
- fn decode<E>(&self, encoded: E) -> Result<(Self::Carrier, Self::Payload), Self::Error>
- where
- E: Into<Self::Output>,
+ fn decode(&self, encoded: &[u8]) -> Result<(Vec<u8>, Vec<u8>), CodecError>
{
- let mut jpeg = match Jpeg::from_bytes(encoded.into().into()) {
- Ok(image) => image,
- Err(err) => return Err(JpegSegmentError::ParseFailed { inner: err })
+ let mut jpeg = match Jpeg::from_bytes(encoded.to_vec().into()) {
+ Ok(v) => v,
+ Err(e) => return Err(CodecError::DependencyError(e.to_string()))
};
let segment = jpeg.segments_mut().remove(self.start_index);
let segment_bytes = segment.contents();
@@ -68,14 +57,3 @@ impl Default for JpegSegmentCodec {
}
}
}
-
-/// Errors thrown by the JPEG segment codec.
-#[derive(Error, Debug)]
-pub enum JpegSegmentError {
- /// Parsing JPEG data failed.
- #[error("Failed to parse JPEG data: {inner:?}")]
- ParseFailed {
- /// Error thrown by parser.
- inner: img_parts::Error,
- }
-}
diff --git a/src/lossless/lsb.rs b/src/lossless/lsb.rs
index 59dcc0b..f8f1113 100644
--- a/src/lossless/lsb.rs
+++ b/src/lossless/lsb.rs
@@ -1,33 +1,25 @@
-use std::cmp::Ordering;
+use std::{cmp::Ordering, io::{BufWriter, Cursor}};
-use image::{ColorType, DynamicImage, GenericImageView, Pixel};
-use thiserror::Error;
+use image::{DynamicImage, GenericImageView, Pixel};
-use crate::codec::Codec;
+use crate::{codec::Codec, CodecError};
/// Least-significant bit (LSB) steganography encodes data in the least-significant bits of colors
/// in an image. This implementation reduces the colors in the carrier (irreversibly) in order to
/// allow a byte of data to fit in each pixel of the image. 3 bits of data are encoded per pixel,
/// and the 9th bit is used to signal the end of data.
-#[derive(Debug)]
+#[derive(Debug, Default)]
pub struct LsbCodec;
impl Codec for LsbCodec {
- type Carrier = DynamicImage;
- type Payload = Vec<u8>;
- type Output = Self::Carrier;
- type Error = LsbError;
-
- fn encode<C, P>(&self, carrier: C, payload: P) -> Result<Self::Output, Self::Error>
- where
- C: Into<Self::Carrier>,
- P: Into<Self::Payload>,
+ fn encode(&self, carrier: &[u8], payload: &[u8]) -> Result<Vec<u8>, CodecError>
{
- let mut image: DynamicImage = carrier.into();
- let payload: Vec<u8> = payload.into();
+ let image_format = image::guess_format(carrier.into()).unwrap();
+ let mut image: DynamicImage = image::load_from_memory(carrier.into()).unwrap();
+ let payload: &[u8] = payload.into();
if image.pixels().count() < payload.len() {
- return Err(LsbError::PayloadTooBig);
+ return Err(CodecError::DataInvalid("Payload Too Big for Carrier".into()));
}
let mut payload_iter = payload.iter();
@@ -51,17 +43,20 @@ impl Codec for LsbCodec {
}
}
},
- _ => return Err(LsbError::UnsupportedFormat { format: image.color() })
+ _ => return Err(CodecError::DataInvalid("Unsupported Image Color Format".into()))
}
- Ok(image)
+ let mut buf = BufWriter::new(Cursor::new(Vec::<u8>::new()));
+ if let Err(e) = image.write_to(&mut buf, image_format) {
+ return Err(CodecError::DependencyError(e.to_string()))
+ }
+ Ok(buf.into_inner().unwrap().into_inner())
}
- fn decode<E>(&self, carrier: E) -> Result<(Self::Carrier, Self::Payload), LsbError>
- where
- E: Into<Self::Output>,
+ fn decode(&self, carrier: &[u8]) -> Result<(Vec<u8>, Vec<u8>), CodecError>
{
- let mut image: DynamicImage = carrier.into();
+ let image_format = image::guess_format(carrier.into()).unwrap();
+ let mut image: DynamicImage = image::load_from_memory(carrier.into()).unwrap();
let mut payload: Vec<u8> = Vec::new();
match image {
@@ -83,10 +78,14 @@ impl Codec for LsbCodec {
}
}
},
- _ => return Err(LsbError::UnsupportedFormat { format: image.color() })
+ _ => return Err(CodecError::DataInvalid("Unsupported Image Color Format".into()))
}
- Ok((image, payload))
+ let mut buf = BufWriter::new(Cursor::new(Vec::<u8>::new()));
+ if let Err(e) = image.write_to(&mut buf, image_format) {
+ return Err(CodecError::DependencyError(e.to_string()))
+ }
+ Ok((buf.into_inner().unwrap().into_inner(), payload))
}
}
@@ -138,19 +137,3 @@ fn decode_pixel<P: Pixel<Subpixel = u8>>(pixel: &mut P) -> Option<u8> {
}
Some(payload_byte)
}
-
-/// Errors thrown by the LSB Codec.
-#[derive(Error, Debug)]
-pub enum LsbError {
-
- /// Error thrown when payload is too big for the carrier.
- #[error("Payload is too big for the carrier. Choose a smaller payload or an image with greater pixel dimensions.")]
- PayloadTooBig,
-
- /// Error thrown when pixel format is unsupported.
- #[error("Specified image format ({format:?}) is unsupported.")]
- UnsupportedFormat {
- /// Provided (invalid) format.
- format: ColorType
- },
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-12 20:37:12 +0000