Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 675 insertions, 0 deletions

diff --git a/third_party/rust/base64/src/encode.rs b/third_party/rust/base64/src/encode.rs
new file mode 100644
index 0000000000..b32bbfff0d
--- /dev/null
+++ b/third_party/rust/base64/src/encode.rs
@@ -0,0 +1,675 @@
+use crate::{Config, PAD_BYTE};
+#[cfg(any(feature = "alloc", feature = "std", test))]
+use crate::{chunked_encoder, STANDARD};
+#[cfg(any(feature = "alloc", feature = "std", test))]
+use alloc::{string::String, vec};
+use core::convert::TryInto;
+
+///Encode arbitrary octets as base64.
+///Returns a String.
+///Convenience for `encode_config(input, base64::STANDARD);`.
+///
+///# Example
+///
+///```rust
+///extern crate base64;
+///
+///fn main() {
+///    let b64 = base64::encode(b"hello world");
+///    println!("{}", b64);
+///}
+///```
+#[cfg(any(feature = "alloc", feature = "std", test))]
+pub fn encode<T: AsRef<[u8]>>(input: T) -> String {
+    encode_config(input, STANDARD)
+}
+
+///Encode arbitrary octets as base64.
+///Returns a String.
+///
+///# Example
+///
+///```rust
+///extern crate base64;
+///
+///fn main() {
+///    let b64 = base64::encode_config(b"hello world~", base64::STANDARD);
+///    println!("{}", b64);
+///
+///    let b64_url = base64::encode_config(b"hello internet~", base64::URL_SAFE);
+///    println!("{}", b64_url);
+///}
+///```
+#[cfg(any(feature = "alloc", feature = "std", test))]
+pub fn encode_config<T: AsRef<[u8]>>(input: T, config: Config) -> String {
+    let mut buf = match encoded_size(input.as_ref().len(), config) {
+        Some(n) => vec![0; n],
+        None => panic!("integer overflow when calculating buffer size"),
+    };
+
+    encode_with_padding(input.as_ref(), config, buf.len(), &mut buf[..]);
+
+    String::from_utf8(buf).expect("Invalid UTF8")
+}
+
+///Encode arbitrary octets as base64.
+///Writes into the supplied output buffer, which will grow the buffer if needed.
+///
+///# Example
+///
+///```rust
+///extern crate base64;
+///
+///fn main() {
+///    let mut buf = String::new();
+///    base64::encode_config_buf(b"hello world~", base64::STANDARD, &mut buf);
+///    println!("{}", buf);
+///
+///    buf.clear();
+///    base64::encode_config_buf(b"hello internet~", base64::URL_SAFE, &mut buf);
+///    println!("{}", buf);
+///}
+///```
+#[cfg(any(feature = "alloc", feature = "std", test))]
+pub fn encode_config_buf<T: AsRef<[u8]>>(input: T, config: Config, buf: &mut String) {
+    let input_bytes = input.as_ref();
+
+    {
+        let mut sink = chunked_encoder::StringSink::new(buf);
+        let encoder = chunked_encoder::ChunkedEncoder::new(config);
+
+        encoder
+            .encode(input_bytes, &mut sink)
+            .expect("Writing to a String shouldn't fail")
+    }
+}
+
+/// Encode arbitrary octets as base64.
+/// Writes into the supplied output buffer.
+///
+/// This is useful if you wish to avoid allocation entirely (e.g. encoding into a stack-resident
+/// or statically-allocated buffer).
+///
+/// # Panics
+///
+/// If `output` is too small to hold the encoded version of `input`, a panic will result.
+///
+/// # Example
+///
+/// ```rust
+/// extern crate base64;
+///
+/// fn main() {
+///     let s = b"hello internet!";
+///     let mut buf = Vec::new();
+///     // make sure we'll have a slice big enough for base64 + padding
+///     buf.resize(s.len() * 4 / 3 + 4, 0);
+///
+///     let bytes_written = base64::encode_config_slice(s,
+///                             base64::STANDARD, &mut buf);
+///
+///     // shorten our vec down to just what was written
+///     buf.resize(bytes_written, 0);
+///
+///     assert_eq!(s, base64::decode(&buf).unwrap().as_slice());
+/// }
+/// ```
+pub fn encode_config_slice<T: AsRef<[u8]>>(input: T, config: Config, output: &mut [u8]) -> usize {
+    let input_bytes = input.as_ref();
+
+    let encoded_size = encoded_size(input_bytes.len(), config)
+        .expect("usize overflow when calculating buffer size");
+
+    let mut b64_output = &mut output[0..encoded_size];
+
+    encode_with_padding(&input_bytes, config, encoded_size, &mut b64_output);
+
+    encoded_size
+}
+
+/// B64-encode and pad (if configured).
+///
+/// This helper exists to avoid recalculating encoded_size, which is relatively expensive on short
+/// inputs.
+///
+/// `encoded_size` is the encoded size calculated for `input`.
+///
+/// `output` must be of size `encoded_size`.
+///
+/// All bytes in `output` will be written to since it is exactly the size of the output.
+fn encode_with_padding(input: &[u8], config: Config, encoded_size: usize, output: &mut [u8]) {
+    debug_assert_eq!(encoded_size, output.len());
+
+    let b64_bytes_written = encode_to_slice(input, output, config.char_set.encode_table());
+
+    let padding_bytes = if config.pad {
+        add_padding(input.len(), &mut output[b64_bytes_written..])
+    } else {
+        0
+    };
+
+    let encoded_bytes = b64_bytes_written
+        .checked_add(padding_bytes)
+        .expect("usize overflow when calculating b64 length");
+
+    debug_assert_eq!(encoded_size, encoded_bytes);
+}
+
+#[inline]
+fn read_u64(s: &[u8]) -> u64 {
+    u64::from_be_bytes(s[..8].try_into().unwrap())
+}
+
+/// Encode input bytes to utf8 base64 bytes. Does not pad.
+/// `output` must be long enough to hold the encoded `input` without padding.
+/// Returns the number of bytes written.
+#[inline]
+pub fn encode_to_slice(input: &[u8], output: &mut [u8], encode_table: &[u8; 64]) -> usize {
+    let mut input_index: usize = 0;
+
+    const BLOCKS_PER_FAST_LOOP: usize = 4;
+    const LOW_SIX_BITS: u64 = 0x3F;
+
+    // we read 8 bytes at a time (u64) but only actually consume 6 of those bytes. Thus, we need
+    // 2 trailing bytes to be available to read..
+    let last_fast_index = input.len().saturating_sub(BLOCKS_PER_FAST_LOOP * 6 + 2);
+    let mut output_index = 0;
+
+    if last_fast_index > 0 {
+        while input_index <= last_fast_index {
+            // Major performance wins from letting the optimizer do the bounds check once, mostly
+            // on the output side
+            let input_chunk = &input[input_index..(input_index + (BLOCKS_PER_FAST_LOOP * 6 + 2))];
+            let output_chunk = &mut output[output_index..(output_index + BLOCKS_PER_FAST_LOOP * 8)];
+
+            // Hand-unrolling for 32 vs 16 or 8 bytes produces yields performance about equivalent
+            // to unsafe pointer code on a Xeon E5-1650v3. 64 byte unrolling was slightly better for
+            // large inputs but significantly worse for 50-byte input, unsurprisingly. I suspect
+            // that it's a not uncommon use case to encode smallish chunks of data (e.g. a 64-byte
+            // SHA-512 digest), so it would be nice if that fit in the unrolled loop at least once.
+            // Plus, single-digit percentage performance differences might well be quite different
+            // on different hardware.
+
+            let input_u64 = read_u64(&input_chunk[0..]);
+
+            output_chunk[0] = encode_table[((input_u64 >> 58) & LOW_SIX_BITS) as usize];
+            output_chunk[1] = encode_table[((input_u64 >> 52) & LOW_SIX_BITS) as usize];
+            output_chunk[2] = encode_table[((input_u64 >> 46) & LOW_SIX_BITS) as usize];
+            output_chunk[3] = encode_table[((input_u64 >> 40) & LOW_SIX_BITS) as usize];
+            output_chunk[4] = encode_table[((input_u64 >> 34) & LOW_SIX_BITS) as usize];
+            output_chunk[5] = encode_table[((input_u64 >> 28) & LOW_SIX_BITS) as usize];
+            output_chunk[6] = encode_table[((input_u64 >> 22) & LOW_SIX_BITS) as usize];
+            output_chunk[7] = encode_table[((input_u64 >> 16) & LOW_SIX_BITS) as usize];
+
+            let input_u64 = read_u64(&input_chunk[6..]);
+
+            output_chunk[8] = encode_table[((input_u64 >> 58) & LOW_SIX_BITS) as usize];
+            output_chunk[9] = encode_table[((input_u64 >> 52) & LOW_SIX_BITS) as usize];
+            output_chunk[10] = encode_table[((input_u64 >> 46) & LOW_SIX_BITS) as usize];
+            output_chunk[11] = encode_table[((input_u64 >> 40) & LOW_SIX_BITS) as usize];
+            output_chunk[12] = encode_table[((input_u64 >> 34) & LOW_SIX_BITS) as usize];
+            output_chunk[13] = encode_table[((input_u64 >> 28) & LOW_SIX_BITS) as usize];
+            output_chunk[14] = encode_table[((input_u64 >> 22) & LOW_SIX_BITS) as usize];
+            output_chunk[15] = encode_table[((input_u64 >> 16) & LOW_SIX_BITS) as usize];
+
+            let input_u64 = read_u64(&input_chunk[12..]);
+
+            output_chunk[16] = encode_table[((input_u64 >> 58) & LOW_SIX_BITS) as usize];
+            output_chunk[17] = encode_table[((input_u64 >> 52) & LOW_SIX_BITS) as usize];
+            output_chunk[18] = encode_table[((input_u64 >> 46) & LOW_SIX_BITS) as usize];
+            output_chunk[19] = encode_table[((input_u64 >> 40) & LOW_SIX_BITS) as usize];
+            output_chunk[20] = encode_table[((input_u64 >> 34) & LOW_SIX_BITS) as usize];
+            output_chunk[21] = encode_table[((input_u64 >> 28) & LOW_SIX_BITS) as usize];
+            output_chunk[22] = encode_table[((input_u64 >> 22) & LOW_SIX_BITS) as usize];
+            output_chunk[23] = encode_table[((input_u64 >> 16) & LOW_SIX_BITS) as usize];
+
+            let input_u64 = read_u64(&input_chunk[18..]);
+
+            output_chunk[24] = encode_table[((input_u64 >> 58) & LOW_SIX_BITS) as usize];
+            output_chunk[25] = encode_table[((input_u64 >> 52) & LOW_SIX_BITS) as usize];
+            output_chunk[26] = encode_table[((input_u64 >> 46) & LOW_SIX_BITS) as usize];
+            output_chunk[27] = encode_table[((input_u64 >> 40) & LOW_SIX_BITS) as usize];
+            output_chunk[28] = encode_table[((input_u64 >> 34) & LOW_SIX_BITS) as usize];
+            output_chunk[29] = encode_table[((input_u64 >> 28) & LOW_SIX_BITS) as usize];
+            output_chunk[30] = encode_table[((input_u64 >> 22) & LOW_SIX_BITS) as usize];
+            output_chunk[31] = encode_table[((input_u64 >> 16) & LOW_SIX_BITS) as usize];
+
+            output_index += BLOCKS_PER_FAST_LOOP * 8;
+            input_index += BLOCKS_PER_FAST_LOOP * 6;
+        }
+    }
+
+    // Encode what's left after the fast loop.
+
+    const LOW_SIX_BITS_U8: u8 = 0x3F;
+
+    let rem = input.len() % 3;
+    let start_of_rem = input.len() - rem;
+
+    // start at the first index not handled by fast loop, which may be 0.
+
+    while input_index < start_of_rem {
+        let input_chunk = &input[input_index..(input_index + 3)];
+        let output_chunk = &mut output[output_index..(output_index + 4)];
+
+        output_chunk[0] = encode_table[(input_chunk[0] >> 2) as usize];
+        output_chunk[1] =
+            encode_table[((input_chunk[0] << 4 | input_chunk[1] >> 4) & LOW_SIX_BITS_U8) as usize];
+        output_chunk[2] =
+            encode_table[((input_chunk[1] << 2 | input_chunk[2] >> 6) & LOW_SIX_BITS_U8) as usize];
+        output_chunk[3] = encode_table[(input_chunk[2] & LOW_SIX_BITS_U8) as usize];
+
+        input_index += 3;
+        output_index += 4;
+    }
+
+    if rem == 2 {
+        output[output_index] = encode_table[(input[start_of_rem] >> 2) as usize];
+        output[output_index + 1] = encode_table[((input[start_of_rem] << 4
+            | input[start_of_rem + 1] >> 4)
+            & LOW_SIX_BITS_U8) as usize];
+        output[output_index + 2] =
+            encode_table[((input[start_of_rem + 1] << 2) & LOW_SIX_BITS_U8) as usize];
+        output_index += 3;
+    } else if rem == 1 {
+        output[output_index] = encode_table[(input[start_of_rem] >> 2) as usize];
+        output[output_index + 1] =
+            encode_table[((input[start_of_rem] << 4) & LOW_SIX_BITS_U8) as usize];
+        output_index += 2;
+    }
+
+    output_index
+}
+
+/// calculate the base64 encoded string size, including padding if appropriate
+pub fn encoded_size(bytes_len: usize, config: Config) -> Option<usize> {
+    let rem = bytes_len % 3;
+
+    let complete_input_chunks = bytes_len / 3;
+    let complete_chunk_output = complete_input_chunks.checked_mul(4);
+
+    if rem > 0 {
+        if config.pad {
+            complete_chunk_output.and_then(|c| c.checked_add(4))
+        } else {
+            let encoded_rem = match rem {
+                1 => 2,
+                2 => 3,
+                _ => unreachable!("Impossible remainder"),
+            };
+            complete_chunk_output.and_then(|c| c.checked_add(encoded_rem))
+        }
+    } else {
+        complete_chunk_output
+    }
+}
+
+/// Write padding characters.
+/// `output` is the slice where padding should be written, of length at least 2.
+///
+/// Returns the number of padding bytes written.
+pub fn add_padding(input_len: usize, output: &mut [u8]) -> usize {
+    let rem = input_len % 3;
+    let mut bytes_written = 0;
+    for _ in 0..((3 - rem) % 3) {
+        output[bytes_written] = PAD_BYTE;
+        bytes_written += 1;
+    }
+
+    bytes_written
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{
+        decode::decode_config_buf,
+        tests::{assert_encode_sanity, random_config},
+        Config, STANDARD, URL_SAFE_NO_PAD,
+    };
+
+    use rand::{
+        distributions::{Distribution, Uniform},
+        FromEntropy, Rng,
+    };
+    use std;
+    use std::str;
+
+    #[test]
+    fn encoded_size_correct_standard() {
+        assert_encoded_length(0, 0, STANDARD);
+
+        assert_encoded_length(1, 4, STANDARD);
+        assert_encoded_length(2, 4, STANDARD);
+        assert_encoded_length(3, 4, STANDARD);
+
+        assert_encoded_length(4, 8, STANDARD);
+        assert_encoded_length(5, 8, STANDARD);
+        assert_encoded_length(6, 8, STANDARD);
+
+        assert_encoded_length(7, 12, STANDARD);
+        assert_encoded_length(8, 12, STANDARD);
+        assert_encoded_length(9, 12, STANDARD);
+
+        assert_encoded_length(54, 72, STANDARD);
+
+        assert_encoded_length(55, 76, STANDARD);
+        assert_encoded_length(56, 76, STANDARD);
+        assert_encoded_length(57, 76, STANDARD);
+
+        assert_encoded_length(58, 80, STANDARD);
+    }
+
+    #[test]
+    fn encoded_size_correct_no_pad() {
+        assert_encoded_length(0, 0, URL_SAFE_NO_PAD);
+
+        assert_encoded_length(1, 2, URL_SAFE_NO_PAD);
+        assert_encoded_length(2, 3, URL_SAFE_NO_PAD);
+        assert_encoded_length(3, 4, URL_SAFE_NO_PAD);
+
+        assert_encoded_length(4, 6, URL_SAFE_NO_PAD);
+        assert_encoded_length(5, 7, URL_SAFE_NO_PAD);
+        assert_encoded_length(6, 8, URL_SAFE_NO_PAD);
+
+        assert_encoded_length(7, 10, URL_SAFE_NO_PAD);
+        assert_encoded_length(8, 11, URL_SAFE_NO_PAD);
+        assert_encoded_length(9, 12, URL_SAFE_NO_PAD);
+
+        assert_encoded_length(54, 72, URL_SAFE_NO_PAD);
+
+        assert_encoded_length(55, 74, URL_SAFE_NO_PAD);
+        assert_encoded_length(56, 75, URL_SAFE_NO_PAD);
+        assert_encoded_length(57, 76, URL_SAFE_NO_PAD);
+
+        assert_encoded_length(58, 78, URL_SAFE_NO_PAD);
+    }
+
+    #[test]
+    fn encoded_size_overflow() {
+        assert_eq!(None, encoded_size(std::usize::MAX, STANDARD));
+    }
+
+    #[test]
+    fn encode_config_buf_into_nonempty_buffer_doesnt_clobber_prefix() {
+        let mut orig_data = Vec::new();
+        let mut prefix = String::new();
+        let mut encoded_data_no_prefix = String::new();
+        let mut encoded_data_with_prefix = String::new();
+        let mut decoded = Vec::new();
+
+        let prefix_len_range = Uniform::new(0, 1000);
+        let input_len_range = Uniform::new(0, 1000);
+
+        let mut rng = rand::rngs::SmallRng::from_entropy();
+
+        for _ in 0..10_000 {
+            orig_data.clear();
+            prefix.clear();
+            encoded_data_no_prefix.clear();
+            encoded_data_with_prefix.clear();
+            decoded.clear();
+
+            let input_len = input_len_range.sample(&mut rng);
+
+            for _ in 0..input_len {
+                orig_data.push(rng.gen());
+            }
+
+            let prefix_len = prefix_len_range.sample(&mut rng);
+            for _ in 0..prefix_len {
+                // getting convenient random single-byte printable chars that aren't base64 is
+                // annoying
+                prefix.push('#');
+            }
+            encoded_data_with_prefix.push_str(&prefix);
+
+            let config = random_config(&mut rng);
+            encode_config_buf(&orig_data, config, &mut encoded_data_no_prefix);
+            encode_config_buf(&orig_data, config, &mut encoded_data_with_prefix);
+
+            assert_eq!(
+                encoded_data_no_prefix.len() + prefix_len,
+                encoded_data_with_prefix.len()
+            );
+            assert_encode_sanity(&encoded_data_no_prefix, config, input_len);
+            assert_encode_sanity(&encoded_data_with_prefix[prefix_len..], config, input_len);
+
+            // append plain encode onto prefix
+            prefix.push_str(&mut encoded_data_no_prefix);
+
+            assert_eq!(prefix, encoded_data_with_prefix);
+
+            decode_config_buf(&encoded_data_no_prefix, config, &mut decoded).unwrap();
+            assert_eq!(orig_data, decoded);
+        }
+    }
+
+    #[test]
+    fn encode_config_slice_into_nonempty_buffer_doesnt_clobber_suffix() {
+        let mut orig_data = Vec::new();
+        let mut encoded_data = Vec::new();
+        let mut encoded_data_original_state = Vec::new();
+        let mut decoded = Vec::new();
+
+        let input_len_range = Uniform::new(0, 1000);
+
+        let mut rng = rand::rngs::SmallRng::from_entropy();
+
+        for _ in 0..10_000 {
+            orig_data.clear();
+            encoded_data.clear();
+            encoded_data_original_state.clear();
+            decoded.clear();
+
+            let input_len = input_len_range.sample(&mut rng);
+
+            for _ in 0..input_len {
+                orig_data.push(rng.gen());
+            }
+
+            // plenty of existing garbage in the encoded buffer
+            for _ in 0..10 * input_len {
+                encoded_data.push(rng.gen());
+            }
+
+            encoded_data_original_state.extend_from_slice(&encoded_data);
+
+            let config = random_config(&mut rng);
+
+            let encoded_size = encoded_size(input_len, config).unwrap();
+
+            assert_eq!(
+                encoded_size,
+                encode_config_slice(&orig_data, config, &mut encoded_data)
+            );
+
+            assert_encode_sanity(
+                std::str::from_utf8(&encoded_data[0..encoded_size]).unwrap(),
+                config,
+                input_len,
+            );
+
+            assert_eq!(
+                &encoded_data[encoded_size..],
+                &encoded_data_original_state[encoded_size..]
+            );
+
+            decode_config_buf(&encoded_data[0..encoded_size], config, &mut decoded).unwrap();
+            assert_eq!(orig_data, decoded);
+        }
+    }
+
+    #[test]
+    fn encode_config_slice_fits_into_precisely_sized_slice() {
+        let mut orig_data = Vec::new();
+        let mut encoded_data = Vec::new();
+        let mut decoded = Vec::new();
+
+        let input_len_range = Uniform::new(0, 1000);
+
+        let mut rng = rand::rngs::SmallRng::from_entropy();
+
+        for _ in 0..10_000 {
+            orig_data.clear();
+            encoded_data.clear();
+            decoded.clear();
+
+            let input_len = input_len_range.sample(&mut rng);
+
+            for _ in 0..input_len {
+                orig_data.push(rng.gen());
+            }
+
+            let config = random_config(&mut rng);
+
+            let encoded_size = encoded_size(input_len, config).unwrap();
+
+            encoded_data.resize(encoded_size, 0);
+
+            assert_eq!(
+                encoded_size,
+                encode_config_slice(&orig_data, config, &mut encoded_data)
+            );
+
+            assert_encode_sanity(
+                std::str::from_utf8(&encoded_data[0..encoded_size]).unwrap(),
+                config,
+                input_len,
+            );
+
+            decode_config_buf(&encoded_data[0..encoded_size], config, &mut decoded).unwrap();
+            assert_eq!(orig_data, decoded);
+        }
+    }
+
+    #[test]
+    fn encode_to_slice_random_valid_utf8() {
+        let mut input = Vec::new();
+        let mut output = Vec::new();
+
+        let input_len_range = Uniform::new(0, 1000);
+
+        let mut rng = rand::rngs::SmallRng::from_entropy();
+
+        for _ in 0..10_000 {
+            input.clear();
+            output.clear();
+
+            let input_len = input_len_range.sample(&mut rng);
+
+            for _ in 0..input_len {
+                input.push(rng.gen());
+            }
+
+            let config = random_config(&mut rng);
+
+            // fill up the output buffer with garbage
+            let encoded_size = encoded_size(input_len, config).unwrap();
+            for _ in 0..encoded_size {
+                output.push(rng.gen());
+            }
+
+            let orig_output_buf = output.to_vec();
+
+            let bytes_written =
+                encode_to_slice(&input, &mut output, config.char_set.encode_table());
+
+            // make sure the part beyond bytes_written is the same garbage it was before
+            assert_eq!(orig_output_buf[bytes_written..], output[bytes_written..]);
+
+            // make sure the encoded bytes are UTF-8
+            let _ = str::from_utf8(&output[0..bytes_written]).unwrap();
+        }
+    }
+
+    #[test]
+    fn encode_with_padding_random_valid_utf8() {
+        let mut input = Vec::new();
+        let mut output = Vec::new();
+
+        let input_len_range = Uniform::new(0, 1000);
+
+        let mut rng = rand::rngs::SmallRng::from_entropy();
+
+        for _ in 0..10_000 {
+            input.clear();
+            output.clear();
+
+            let input_len = input_len_range.sample(&mut rng);
+
+            for _ in 0..input_len {
+                input.push(rng.gen());
+            }
+
+            let config = random_config(&mut rng);
+
+            // fill up the output buffer with garbage
+            let encoded_size = encoded_size(input_len, config).unwrap();
+            for _ in 0..encoded_size + 1000 {
+                output.push(rng.gen());
+            }
+
+            let orig_output_buf = output.to_vec();
+
+            encode_with_padding(&input, config, encoded_size, &mut output[0..encoded_size]);
+
+            // make sure the part beyond b64 is the same garbage it was before
+            assert_eq!(orig_output_buf[encoded_size..], output[encoded_size..]);
+
+            // make sure the encoded bytes are UTF-8
+            let _ = str::from_utf8(&output[0..encoded_size]).unwrap();
+        }
+    }
+
+    #[test]
+    fn add_padding_random_valid_utf8() {
+        let mut output = Vec::new();
+
+        let mut rng = rand::rngs::SmallRng::from_entropy();
+
+        // cover our bases for length % 3
+        for input_len in 0..10 {
+            output.clear();
+
+            // fill output with random
+            for _ in 0..10 {
+                output.push(rng.gen());
+            }
+
+            let orig_output_buf = output.to_vec();
+
+            let bytes_written = add_padding(input_len, &mut output);
+
+            // make sure the part beyond bytes_written is the same garbage it was before
+            assert_eq!(orig_output_buf[bytes_written..], output[bytes_written..]);
+
+            // make sure the encoded bytes are UTF-8
+            let _ = str::from_utf8(&output[0..bytes_written]).unwrap();
+        }
+    }
+
+    fn assert_encoded_length(input_len: usize, encoded_len: usize, config: Config) {
+        assert_eq!(encoded_len, encoded_size(input_len, config).unwrap());
+
+        let mut bytes: Vec<u8> = Vec::new();
+        let mut rng = rand::rngs::SmallRng::from_entropy();
+
+        for _ in 0..input_len {
+            bytes.push(rng.gen());
+        }
+
+        let encoded = encode_config(&bytes, config);
+        assert_encode_sanity(&encoded, config, input_len);
+
+        assert_eq!(encoded_len, encoded.len());
+    }
+
+    #[test]
+    fn encode_imap() {
+        assert_eq!(
+            encode_config(b"\xFB\xFF", crate::IMAP_MUTF7),
+            encode_config(b"\xFB\xFF", crate::STANDARD_NO_PAD).replace("/", ",")
+        );
+    }
+}