| // SPDX-License-Identifier: MIT |
| |
| //! This is a simple QR encoder for DRM panic. |
| //! |
| //! It is called from a panic handler, so it should't allocate memory and |
| //! does all the work on the stack or on the provided buffers. For |
| //! simplification, it only supports low error correction, and applies the |
| //! first mask (checkerboard). It will draw the smallest QRcode that can |
| //! contain the string passed as parameter. To get the most compact |
| //! QR code, the start of the URL is encoded as binary, and the |
| //! compressed kmsg is encoded as numeric. |
| //! |
| //! The binary data must be a valid URL parameter, so the easiest way is |
| //! to use base64 encoding. But this wastes 25% of data space, so the |
| //! whole stack trace won't fit in the QR code. So instead it encodes |
| //! every 13bits of input into 4 decimal digits, and then uses the |
| //! efficient numeric encoding, that encode 3 decimal digits into |
| //! 10bits. This makes 39bits of compressed data into 12 decimal digits, |
| //! into 40bits in the QR code, so wasting only 2.5%. And the numbers are |
| //! valid URL parameter, so the website can do the reverse, to get the |
| //! binary data. |
| //! |
| //! Inspired by these 3 projects, all under MIT license: |
| //! |
| //! * <https://github.com/kennytm/qrcode-rust> |
| //! * <https://github.com/erwanvivien/fast_qr> |
| //! * <https://github.com/bjguillot/qr> |
| |
| use core::cmp; |
| use kernel::str::CStr; |
| |
| #[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd)] |
| struct Version(usize); |
| |
| // Generator polynomials for ECC, only those that are needed for low quality. |
| const P7: [u8; 7] = [87, 229, 146, 149, 238, 102, 21]; |
| const P10: [u8; 10] = [251, 67, 46, 61, 118, 70, 64, 94, 32, 45]; |
| const P15: [u8; 15] = [ |
| 8, 183, 61, 91, 202, 37, 51, 58, 58, 237, 140, 124, 5, 99, 105, |
| ]; |
| const P18: [u8; 18] = [ |
| 215, 234, 158, 94, 184, 97, 118, 170, 79, 187, 152, 148, 252, 179, 5, 98, 96, 153, |
| ]; |
| const P20: [u8; 20] = [ |
| 17, 60, 79, 50, 61, 163, 26, 187, 202, 180, 221, 225, 83, 239, 156, 164, 212, 212, 188, 190, |
| ]; |
| const P22: [u8; 22] = [ |
| 210, 171, 247, 242, 93, 230, 14, 109, 221, 53, 200, 74, 8, 172, 98, 80, 219, 134, 160, 105, |
| 165, 231, |
| ]; |
| const P24: [u8; 24] = [ |
| 229, 121, 135, 48, 211, 117, 251, 126, 159, 180, 169, 152, 192, 226, 228, 218, 111, 0, 117, |
| 232, 87, 96, 227, 21, |
| ]; |
| const P26: [u8; 26] = [ |
| 173, 125, 158, 2, 103, 182, 118, 17, 145, 201, 111, 28, 165, 53, 161, 21, 245, 142, 13, 102, |
| 48, 227, 153, 145, 218, 70, |
| ]; |
| const P28: [u8; 28] = [ |
| 168, 223, 200, 104, 224, 234, 108, 180, 110, 190, 195, 147, 205, 27, 232, 201, 21, 43, 245, 87, |
| 42, 195, 212, 119, 242, 37, 9, 123, |
| ]; |
| const P30: [u8; 30] = [ |
| 41, 173, 145, 152, 216, 31, 179, 182, 50, 48, 110, 86, 239, 96, 222, 125, 42, 173, 226, 193, |
| 224, 130, 156, 37, 251, 216, 238, 40, 192, 180, |
| ]; |
| |
| /// QR Code parameters for Low quality ECC: |
| /// - Error Correction polynomial. |
| /// - Number of blocks in group 1. |
| /// - Number of blocks in group 2. |
| /// - Block size in group 1. |
| /// |
| /// (Block size in group 2 is one more than group 1). |
| struct VersionParameter(&'static [u8], u8, u8, u8); |
| const VPARAM: [VersionParameter; 40] = [ |
| VersionParameter(&P7, 1, 0, 19), // V1 |
| VersionParameter(&P10, 1, 0, 34), // V2 |
| VersionParameter(&P15, 1, 0, 55), // V3 |
| VersionParameter(&P20, 1, 0, 80), // V4 |
| VersionParameter(&P26, 1, 0, 108), // V5 |
| VersionParameter(&P18, 2, 0, 68), // V6 |
| VersionParameter(&P20, 2, 0, 78), // V7 |
| VersionParameter(&P24, 2, 0, 97), // V8 |
| VersionParameter(&P30, 2, 0, 116), // V9 |
| VersionParameter(&P18, 2, 2, 68), // V10 |
| VersionParameter(&P20, 4, 0, 81), // V11 |
| VersionParameter(&P24, 2, 2, 92), // V12 |
| VersionParameter(&P26, 4, 0, 107), // V13 |
| VersionParameter(&P30, 3, 1, 115), // V14 |
| VersionParameter(&P22, 5, 1, 87), // V15 |
| VersionParameter(&P24, 5, 1, 98), // V16 |
| VersionParameter(&P28, 1, 5, 107), // V17 |
| VersionParameter(&P30, 5, 1, 120), // V18 |
| VersionParameter(&P28, 3, 4, 113), // V19 |
| VersionParameter(&P28, 3, 5, 107), // V20 |
| VersionParameter(&P28, 4, 4, 116), // V21 |
| VersionParameter(&P28, 2, 7, 111), // V22 |
| VersionParameter(&P30, 4, 5, 121), // V23 |
| VersionParameter(&P30, 6, 4, 117), // V24 |
| VersionParameter(&P26, 8, 4, 106), // V25 |
| VersionParameter(&P28, 10, 2, 114), // V26 |
| VersionParameter(&P30, 8, 4, 122), // V27 |
| VersionParameter(&P30, 3, 10, 117), // V28 |
| VersionParameter(&P30, 7, 7, 116), // V29 |
| VersionParameter(&P30, 5, 10, 115), // V30 |
| VersionParameter(&P30, 13, 3, 115), // V31 |
| VersionParameter(&P30, 17, 0, 115), // V32 |
| VersionParameter(&P30, 17, 1, 115), // V33 |
| VersionParameter(&P30, 13, 6, 115), // V34 |
| VersionParameter(&P30, 12, 7, 121), // V35 |
| VersionParameter(&P30, 6, 14, 121), // V36 |
| VersionParameter(&P30, 17, 4, 122), // V37 |
| VersionParameter(&P30, 4, 18, 122), // V38 |
| VersionParameter(&P30, 20, 4, 117), // V39 |
| VersionParameter(&P30, 19, 6, 118), // V40 |
| ]; |
| |
| const MAX_EC_SIZE: usize = 30; |
| const MAX_BLK_SIZE: usize = 123; |
| |
| /// Position of the alignment pattern grid. |
| const ALIGNMENT_PATTERNS: [&[u8]; 40] = [ |
| &[], |
| &[6, 18], |
| &[6, 22], |
| &[6, 26], |
| &[6, 30], |
| &[6, 34], |
| &[6, 22, 38], |
| &[6, 24, 42], |
| &[6, 26, 46], |
| &[6, 28, 50], |
| &[6, 30, 54], |
| &[6, 32, 58], |
| &[6, 34, 62], |
| &[6, 26, 46, 66], |
| &[6, 26, 48, 70], |
| &[6, 26, 50, 74], |
| &[6, 30, 54, 78], |
| &[6, 30, 56, 82], |
| &[6, 30, 58, 86], |
| &[6, 34, 62, 90], |
| &[6, 28, 50, 72, 94], |
| &[6, 26, 50, 74, 98], |
| &[6, 30, 54, 78, 102], |
| &[6, 28, 54, 80, 106], |
| &[6, 32, 58, 84, 110], |
| &[6, 30, 58, 86, 114], |
| &[6, 34, 62, 90, 118], |
| &[6, 26, 50, 74, 98, 122], |
| &[6, 30, 54, 78, 102, 126], |
| &[6, 26, 52, 78, 104, 130], |
| &[6, 30, 56, 82, 108, 134], |
| &[6, 34, 60, 86, 112, 138], |
| &[6, 30, 58, 86, 114, 142], |
| &[6, 34, 62, 90, 118, 146], |
| &[6, 30, 54, 78, 102, 126, 150], |
| &[6, 24, 50, 76, 102, 128, 154], |
| &[6, 28, 54, 80, 106, 132, 158], |
| &[6, 32, 58, 84, 110, 136, 162], |
| &[6, 26, 54, 82, 110, 138, 166], |
| &[6, 30, 58, 86, 114, 142, 170], |
| ]; |
| |
| /// Version information for format V7-V40. |
| const VERSION_INFORMATION: [u32; 34] = [ |
| 0b00_0111_1100_1001_0100, |
| 0b00_1000_0101_1011_1100, |
| 0b00_1001_1010_1001_1001, |
| 0b00_1010_0100_1101_0011, |
| 0b00_1011_1011_1111_0110, |
| 0b00_1100_0111_0110_0010, |
| 0b00_1101_1000_0100_0111, |
| 0b00_1110_0110_0000_1101, |
| 0b00_1111_1001_0010_1000, |
| 0b01_0000_1011_0111_1000, |
| 0b01_0001_0100_0101_1101, |
| 0b01_0010_1010_0001_0111, |
| 0b01_0011_0101_0011_0010, |
| 0b01_0100_1001_1010_0110, |
| 0b01_0101_0110_1000_0011, |
| 0b01_0110_1000_1100_1001, |
| 0b01_0111_0111_1110_1100, |
| 0b01_1000_1110_1100_0100, |
| 0b01_1001_0001_1110_0001, |
| 0b01_1010_1111_1010_1011, |
| 0b01_1011_0000_1000_1110, |
| 0b01_1100_1100_0001_1010, |
| 0b01_1101_0011_0011_1111, |
| 0b01_1110_1101_0111_0101, |
| 0b01_1111_0010_0101_0000, |
| 0b10_0000_1001_1101_0101, |
| 0b10_0001_0110_1111_0000, |
| 0b10_0010_1000_1011_1010, |
| 0b10_0011_0111_1001_1111, |
| 0b10_0100_1011_0000_1011, |
| 0b10_0101_0100_0010_1110, |
| 0b10_0110_1010_0110_0100, |
| 0b10_0111_0101_0100_0001, |
| 0b10_1000_1100_0110_1001, |
| ]; |
| |
| /// Format info for low quality ECC. |
| const FORMAT_INFOS_QR_L: [u16; 8] = [ |
| 0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976, |
| ]; |
| |
| impl Version { |
| /// Returns the smallest QR version than can hold these segments. |
| fn from_segments(segments: &[&Segment<'_>]) -> Option<Version> { |
| for v in (1..=40).map(|k| Version(k)) { |
| if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() { |
| return Some(v); |
| } |
| } |
| None |
| } |
| |
| fn width(&self) -> u8 { |
| (self.0 as u8) * 4 + 17 |
| } |
| |
| fn max_data(&self) -> usize { |
| self.g1_blk_size() * self.g1_blocks() + (self.g1_blk_size() + 1) * self.g2_blocks() |
| } |
| |
| fn ec_size(&self) -> usize { |
| VPARAM[self.0 - 1].0.len() |
| } |
| |
| fn g1_blocks(&self) -> usize { |
| VPARAM[self.0 - 1].1 as usize |
| } |
| |
| fn g2_blocks(&self) -> usize { |
| VPARAM[self.0 - 1].2 as usize |
| } |
| |
| fn g1_blk_size(&self) -> usize { |
| VPARAM[self.0 - 1].3 as usize |
| } |
| |
| fn alignment_pattern(&self) -> &'static [u8] { |
| &ALIGNMENT_PATTERNS[self.0 - 1] |
| } |
| |
| fn poly(&self) -> &'static [u8] { |
| VPARAM[self.0 - 1].0 |
| } |
| |
| fn version_info(&self) -> u32 { |
| if *self >= Version(7) { |
| VERSION_INFORMATION[self.0 - 7] |
| } else { |
| 0 |
| } |
| } |
| } |
| |
| /// Exponential table for Galois Field GF(256). |
| const EXP_TABLE: [u8; 256] = [ |
| 1, 2, 4, 8, 16, 32, 64, 128, 29, 58, 116, 232, 205, 135, 19, 38, 76, 152, 45, 90, 180, 117, |
| 234, 201, 143, 3, 6, 12, 24, 48, 96, 192, 157, 39, 78, 156, 37, 74, 148, 53, 106, 212, 181, |
| 119, 238, 193, 159, 35, 70, 140, 5, 10, 20, 40, 80, 160, 93, 186, 105, 210, 185, 111, 222, 161, |
| 95, 190, 97, 194, 153, 47, 94, 188, 101, 202, 137, 15, 30, 60, 120, 240, 253, 231, 211, 187, |
| 107, 214, 177, 127, 254, 225, 223, 163, 91, 182, 113, 226, 217, 175, 67, 134, 17, 34, 68, 136, |
| 13, 26, 52, 104, 208, 189, 103, 206, 129, 31, 62, 124, 248, 237, 199, 147, 59, 118, 236, 197, |
| 151, 51, 102, 204, 133, 23, 46, 92, 184, 109, 218, 169, 79, 158, 33, 66, 132, 21, 42, 84, 168, |
| 77, 154, 41, 82, 164, 85, 170, 73, 146, 57, 114, 228, 213, 183, 115, 230, 209, 191, 99, 198, |
| 145, 63, 126, 252, 229, 215, 179, 123, 246, 241, 255, 227, 219, 171, 75, 150, 49, 98, 196, 149, |
| 55, 110, 220, 165, 87, 174, 65, 130, 25, 50, 100, 200, 141, 7, 14, 28, 56, 112, 224, 221, 167, |
| 83, 166, 81, 162, 89, 178, 121, 242, 249, 239, 195, 155, 43, 86, 172, 69, 138, 9, 18, 36, 72, |
| 144, 61, 122, 244, 245, 247, 243, 251, 235, 203, 139, 11, 22, 44, 88, 176, 125, 250, 233, 207, |
| 131, 27, 54, 108, 216, 173, 71, 142, 1, |
| ]; |
| |
| /// Reverse exponential table for Galois Field GF(256). |
| const LOG_TABLE: [u8; 256] = [ |
| 175, 0, 1, 25, 2, 50, 26, 198, 3, 223, 51, 238, 27, 104, 199, 75, 4, 100, 224, 14, 52, 141, |
| 239, 129, 28, 193, 105, 248, 200, 8, 76, 113, 5, 138, 101, 47, 225, 36, 15, 33, 53, 147, 142, |
| 218, 240, 18, 130, 69, 29, 181, 194, 125, 106, 39, 249, 185, 201, 154, 9, 120, 77, 228, 114, |
| 166, 6, 191, 139, 98, 102, 221, 48, 253, 226, 152, 37, 179, 16, 145, 34, 136, 54, 208, 148, |
| 206, 143, 150, 219, 189, 241, 210, 19, 92, 131, 56, 70, 64, 30, 66, 182, 163, 195, 72, 126, |
| 110, 107, 58, 40, 84, 250, 133, 186, 61, 202, 94, 155, 159, 10, 21, 121, 43, 78, 212, 229, 172, |
| 115, 243, 167, 87, 7, 112, 192, 247, 140, 128, 99, 13, 103, 74, 222, 237, 49, 197, 254, 24, |
| 227, 165, 153, 119, 38, 184, 180, 124, 17, 68, 146, 217, 35, 32, 137, 46, 55, 63, 209, 91, 149, |
| 188, 207, 205, 144, 135, 151, 178, 220, 252, 190, 97, 242, 86, 211, 171, 20, 42, 93, 158, 132, |
| 60, 57, 83, 71, 109, 65, 162, 31, 45, 67, 216, 183, 123, 164, 118, 196, 23, 73, 236, 127, 12, |
| 111, 246, 108, 161, 59, 82, 41, 157, 85, 170, 251, 96, 134, 177, 187, 204, 62, 90, 203, 89, 95, |
| 176, 156, 169, 160, 81, 11, 245, 22, 235, 122, 117, 44, 215, 79, 174, 213, 233, 230, 231, 173, |
| 232, 116, 214, 244, 234, 168, 80, 88, 175, |
| ]; |
| |
| // 4 bits segment header. |
| const MODE_STOP: u16 = 0; |
| const MODE_NUMERIC: u16 = 1; |
| const MODE_BINARY: u16 = 4; |
| /// Padding bytes. |
| const PADDING: [u8; 2] = [236, 17]; |
| |
| /// Get the next 13 bits of data, starting at specified offset (in bits). |
| fn get_next_13b(data: &[u8], offset: usize) -> Option<(u16, usize)> { |
| if offset < data.len() * 8 { |
| let size = cmp::min(13, data.len() * 8 - offset); |
| let byte_off = offset / 8; |
| let bit_off = offset % 8; |
| // `b` is 20 at max (`bit_off` <= 7 and `size` <= 13). |
| let b = (bit_off + size) as u16; |
| |
| let first_byte = (data[byte_off] << bit_off >> bit_off) as u16; |
| |
| let number = match b { |
| 0..=8 => first_byte >> (8 - b), |
| 9..=16 => (first_byte << (b - 8)) + (data[byte_off + 1] >> (16 - b)) as u16, |
| _ => { |
| (first_byte << (b - 8)) |
| + ((data[byte_off + 1] as u16) << (b - 16)) |
| + (data[byte_off + 2] >> (24 - b)) as u16 |
| } |
| }; |
| Some((number, size)) |
| } else { |
| None |
| } |
| } |
| |
| /// Number of bits to encode characters in numeric mode. |
| const NUM_CHARS_BITS: [usize; 4] = [0, 4, 7, 10]; |
| const POW10: [u16; 4] = [1, 10, 100, 1000]; |
| |
| enum Segment<'a> { |
| Numeric(&'a [u8]), |
| Binary(&'a [u8]), |
| } |
| |
| impl Segment<'_> { |
| fn get_header(&self) -> (u16, usize) { |
| match self { |
| Segment::Binary(_) => (MODE_BINARY, 4), |
| Segment::Numeric(_) => (MODE_NUMERIC, 4), |
| } |
| } |
| |
| // Returns the size of the length field in bits, depending on QR Version. |
| fn length_bits_count(&self, version: Version) -> usize { |
| let Version(v) = version; |
| match self { |
| Segment::Binary(_) => match v { |
| 1..=9 => 8, |
| _ => 16, |
| }, |
| Segment::Numeric(_) => match v { |
| 1..=9 => 10, |
| 10..=26 => 12, |
| _ => 14, |
| }, |
| } |
| } |
| |
| // Number of characters in the segment. |
| fn character_count(&self) -> usize { |
| match self { |
| Segment::Binary(data) => data.len(), |
| Segment::Numeric(data) => { |
| let data_bits = data.len() * 8; |
| let last_chars = match data_bits % 13 { |
| 1 => 1, |
| k => (k + 1) / 3, |
| }; |
| // 4 decimal numbers per 13bits + remainder. |
| 4 * (data_bits / 13) + last_chars |
| } |
| } |
| } |
| |
| fn get_length_field(&self, version: Version) -> (u16, usize) { |
| ( |
| self.character_count() as u16, |
| self.length_bits_count(version), |
| ) |
| } |
| |
| fn total_size_bits(&self, version: Version) -> usize { |
| let data_size = match self { |
| Segment::Binary(data) => data.len() * 8, |
| Segment::Numeric(_) => { |
| let digits = self.character_count(); |
| 10 * (digits / 3) + NUM_CHARS_BITS[digits % 3] |
| } |
| }; |
| // header + length + data. |
| 4 + self.length_bits_count(version) + data_size |
| } |
| |
| fn iter(&self) -> SegmentIterator<'_> { |
| SegmentIterator { |
| segment: self, |
| offset: 0, |
| carry: 0, |
| carry_len: 0, |
| } |
| } |
| } |
| |
| struct SegmentIterator<'a> { |
| segment: &'a Segment<'a>, |
| offset: usize, |
| carry: u16, |
| carry_len: usize, |
| } |
| |
| impl Iterator for SegmentIterator<'_> { |
| type Item = (u16, usize); |
| |
| fn next(&mut self) -> Option<Self::Item> { |
| match self.segment { |
| Segment::Binary(data) => { |
| if self.offset < data.len() { |
| let byte = data[self.offset] as u16; |
| self.offset += 1; |
| Some((byte, 8)) |
| } else { |
| None |
| } |
| } |
| Segment::Numeric(data) => { |
| if self.carry_len == 3 { |
| let out = (self.carry, NUM_CHARS_BITS[self.carry_len]); |
| self.carry_len = 0; |
| self.carry = 0; |
| Some(out) |
| } else if let Some((bits, size)) = get_next_13b(data, self.offset) { |
| self.offset += size; |
| let new_chars = match size { |
| 1 => 1, |
| k => (k + 1) / 3, |
| }; |
| if self.carry_len + new_chars > 3 { |
| self.carry_len = new_chars + self.carry_len - 3; |
| let out = ( |
| self.carry * POW10[new_chars - self.carry_len] |
| + bits / POW10[self.carry_len], |
| NUM_CHARS_BITS[3], |
| ); |
| self.carry = bits % POW10[self.carry_len]; |
| Some(out) |
| } else { |
| let out = ( |
| self.carry * POW10[new_chars] + bits, |
| NUM_CHARS_BITS[self.carry_len + new_chars], |
| ); |
| self.carry_len = 0; |
| Some(out) |
| } |
| } else if self.carry_len > 0 { |
| let out = (self.carry, NUM_CHARS_BITS[self.carry_len]); |
| self.carry_len = 0; |
| Some(out) |
| } else { |
| None |
| } |
| } |
| } |
| } |
| } |
| |
| struct EncodedMsg<'a> { |
| data: &'a mut [u8], |
| ec_size: usize, |
| g1_blocks: usize, |
| g2_blocks: usize, |
| g1_blk_size: usize, |
| g2_blk_size: usize, |
| poly: &'static [u8], |
| version: Version, |
| } |
| |
| /// Data to be put in the QR code, with correct segment encoding, padding, and |
| /// Error Code Correction. |
| impl EncodedMsg<'_> { |
| fn new<'a, 'b>(segments: &[&Segment<'b>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> { |
| let version = Version::from_segments(segments)?; |
| let ec_size = version.ec_size(); |
| let g1_blocks = version.g1_blocks(); |
| let g2_blocks = version.g2_blocks(); |
| let g1_blk_size = version.g1_blk_size(); |
| let g2_blk_size = g1_blk_size + 1; |
| let poly = version.poly(); |
| |
| // clear the output. |
| data.fill(0); |
| |
| let mut em = EncodedMsg { |
| data: data, |
| ec_size, |
| g1_blocks, |
| g2_blocks, |
| g1_blk_size, |
| g2_blk_size, |
| poly, |
| version, |
| }; |
| em.encode(segments); |
| Some(em) |
| } |
| |
| /// Push bits of data at an offset (in bits). |
| fn push(&mut self, offset: &mut usize, bits: (u16, usize)) { |
| let (number, len_bits) = bits; |
| let byte_off = *offset / 8; |
| let bit_off = *offset % 8; |
| let b = bit_off + len_bits; |
| |
| match (bit_off, b) { |
| (0, 0..=8) => { |
| self.data[byte_off] = (number << (8 - b)) as u8; |
| } |
| (0, _) => { |
| self.data[byte_off] = (number >> (b - 8)) as u8; |
| self.data[byte_off + 1] = (number << (16 - b)) as u8; |
| } |
| (_, 0..=8) => { |
| self.data[byte_off] |= (number << (8 - b)) as u8; |
| } |
| (_, 9..=16) => { |
| self.data[byte_off] |= (number >> (b - 8)) as u8; |
| self.data[byte_off + 1] = (number << (16 - b)) as u8; |
| } |
| _ => { |
| self.data[byte_off] |= (number >> (b - 8)) as u8; |
| self.data[byte_off + 1] = (number >> (b - 16)) as u8; |
| self.data[byte_off + 2] = (number << (24 - b)) as u8; |
| } |
| } |
| *offset += len_bits; |
| } |
| |
| fn add_segments(&mut self, segments: &[&Segment<'_>]) { |
| let mut offset: usize = 0; |
| |
| for s in segments.iter() { |
| self.push(&mut offset, s.get_header()); |
| self.push(&mut offset, s.get_length_field(self.version)); |
| for bits in s.iter() { |
| self.push(&mut offset, bits); |
| } |
| } |
| self.push(&mut offset, (MODE_STOP, 4)); |
| |
| let pad_offset = (offset + 7) / 8; |
| for i in pad_offset..self.version.max_data() { |
| self.data[i] = PADDING[(i & 1) ^ (pad_offset & 1)]; |
| } |
| } |
| |
| fn error_code_for_blocks(&mut self, offset: usize, size: usize, ec_offset: usize) { |
| let mut tmp: [u8; MAX_BLK_SIZE + MAX_EC_SIZE] = [0; MAX_BLK_SIZE + MAX_EC_SIZE]; |
| |
| tmp[0..size].copy_from_slice(&self.data[offset..offset + size]); |
| for i in 0..size { |
| let lead_coeff = tmp[i] as usize; |
| if lead_coeff == 0 { |
| continue; |
| } |
| let log_lead_coeff = usize::from(LOG_TABLE[lead_coeff]); |
| for (u, &v) in tmp[i + 1..].iter_mut().zip(self.poly.iter()) { |
| *u ^= EXP_TABLE[(usize::from(v) + log_lead_coeff) % 255]; |
| } |
| } |
| self.data[ec_offset..ec_offset + self.ec_size] |
| .copy_from_slice(&tmp[size..size + self.ec_size]); |
| } |
| |
| fn compute_error_code(&mut self) { |
| let mut offset = 0; |
| let mut ec_offset = self.g1_blocks * self.g1_blk_size + self.g2_blocks * self.g2_blk_size; |
| |
| for _ in 0..self.g1_blocks { |
| self.error_code_for_blocks(offset, self.g1_blk_size, ec_offset); |
| offset += self.g1_blk_size; |
| ec_offset += self.ec_size; |
| } |
| for _ in 0..self.g2_blocks { |
| self.error_code_for_blocks(offset, self.g2_blk_size, ec_offset); |
| offset += self.g2_blk_size; |
| ec_offset += self.ec_size; |
| } |
| } |
| |
| fn encode(&mut self, segments: &[&Segment<'_>]) { |
| self.add_segments(segments); |
| self.compute_error_code(); |
| } |
| |
| fn iter(&self) -> EncodedMsgIterator<'_> { |
| EncodedMsgIterator { |
| em: self, |
| offset: 0, |
| } |
| } |
| } |
| |
| /// Iterator, to retrieve the data in the interleaved order needed by QR code. |
| struct EncodedMsgIterator<'a> { |
| em: &'a EncodedMsg<'a>, |
| offset: usize, |
| } |
| |
| impl Iterator for EncodedMsgIterator<'_> { |
| type Item = u8; |
| |
| // Send the bytes in interleaved mode, first byte of first block of group1, |
| // then first byte of second block of group1, ... |
| fn next(&mut self) -> Option<Self::Item> { |
| let em = self.em; |
| let blocks = em.g1_blocks + em.g2_blocks; |
| let g1_end = em.g1_blocks * em.g1_blk_size; |
| let g2_end = g1_end + em.g2_blocks * em.g2_blk_size; |
| let ec_end = g2_end + em.ec_size * blocks; |
| |
| if self.offset >= ec_end { |
| return None; |
| } |
| |
| let offset = if self.offset < em.g1_blk_size * blocks { |
| // group1 and group2 interleaved |
| let blk = self.offset % blocks; |
| let blk_off = self.offset / blocks; |
| if blk < em.g1_blocks { |
| blk * em.g1_blk_size + blk_off |
| } else { |
| g1_end + em.g2_blk_size * (blk - em.g1_blocks) + blk_off |
| } |
| } else if self.offset < g2_end { |
| // last byte of group2 blocks |
| let blk2 = self.offset - blocks * em.g1_blk_size; |
| em.g1_blk_size * em.g1_blocks + blk2 * em.g2_blk_size + em.g2_blk_size - 1 |
| } else { |
| // EC blocks |
| let ec_offset = self.offset - g2_end; |
| let blk = ec_offset % blocks; |
| let blk_off = ec_offset / blocks; |
| |
| g2_end + blk * em.ec_size + blk_off |
| }; |
| self.offset += 1; |
| Some(em.data[offset]) |
| } |
| } |
| |
| /// A QR code image, encoded as a linear binary framebuffer. |
| /// 1 bit per module (pixel), each new line start at next byte boundary. |
| /// Max width is 177 for V40 QR code, so `u8` is enough for coordinate. |
| struct QrImage<'a> { |
| data: &'a mut [u8], |
| width: u8, |
| stride: u8, |
| version: Version, |
| } |
| |
| impl QrImage<'_> { |
| fn new<'a, 'b>(em: &'b EncodedMsg<'b>, qrdata: &'a mut [u8]) -> QrImage<'a> { |
| let width = em.version.width(); |
| let stride = (width + 7) / 8; |
| let data = qrdata; |
| |
| let mut qr_image = QrImage { |
| data, |
| width, |
| stride, |
| version: em.version, |
| }; |
| qr_image.draw_all(em.iter()); |
| qr_image |
| } |
| |
| fn clear(&mut self) { |
| self.data.fill(0); |
| } |
| |
| // Set pixel to light color. |
| fn set(&mut self, x: u8, y: u8) { |
| let off = y as usize * self.stride as usize + x as usize / 8; |
| let mut v = self.data[off]; |
| v |= 0x80 >> (x % 8); |
| self.data[off] = v; |
| } |
| |
| // Invert a module color. |
| fn xor(&mut self, x: u8, y: u8) { |
| let off = y as usize * self.stride as usize + x as usize / 8; |
| self.data[off] ^= 0x80 >> (x % 8); |
| } |
| |
| // Draw a light square at (x, y) top left corner. |
| fn draw_square(&mut self, x: u8, y: u8, size: u8) { |
| for k in 0..size { |
| self.set(x + k, y); |
| self.set(x, y + k + 1); |
| self.set(x + size, y + k); |
| self.set(x + k + 1, y + size); |
| } |
| } |
| |
| // Finder pattern: 3 8x8 square at the corners. |
| fn draw_finders(&mut self) { |
| self.draw_square(1, 1, 4); |
| self.draw_square(self.width - 6, 1, 4); |
| self.draw_square(1, self.width - 6, 4); |
| for k in 0..8 { |
| self.set(k, 7); |
| self.set(self.width - k - 1, 7); |
| self.set(k, self.width - 8); |
| } |
| for k in 0..7 { |
| self.set(7, k); |
| self.set(self.width - 8, k); |
| self.set(7, self.width - 1 - k); |
| } |
| } |
| |
| fn is_finder(&self, x: u8, y: u8) -> bool { |
| let end = self.width - 8; |
| (x < 8 && y < 8) || (x < 8 && y >= end) || (x >= end && y < 8) |
| } |
| |
| // Alignment pattern: 5x5 squares in a grid. |
| fn draw_alignments(&mut self) { |
| let positions = self.version.alignment_pattern(); |
| for &x in positions.iter() { |
| for &y in positions.iter() { |
| if !self.is_finder(x, y) { |
| self.draw_square(x - 1, y - 1, 2); |
| } |
| } |
| } |
| } |
| |
| fn is_alignment(&self, x: u8, y: u8) -> bool { |
| let positions = self.version.alignment_pattern(); |
| for &ax in positions.iter() { |
| for &ay in positions.iter() { |
| if self.is_finder(ax, ay) { |
| continue; |
| } |
| if x >= ax - 2 && x <= ax + 2 && y >= ay - 2 && y <= ay + 2 { |
| return true; |
| } |
| } |
| } |
| false |
| } |
| |
| // Timing pattern: 2 dotted line between the finder patterns. |
| fn draw_timing_patterns(&mut self) { |
| let end = self.width - 8; |
| |
| for x in (9..end).step_by(2) { |
| self.set(x, 6); |
| self.set(6, x); |
| } |
| } |
| |
| fn is_timing(&self, x: u8, y: u8) -> bool { |
| x == 6 || y == 6 |
| } |
| |
| // Mask info: 15 bits around the finders, written twice for redundancy. |
| fn draw_maskinfo(&mut self) { |
| let info: u16 = FORMAT_INFOS_QR_L[0]; |
| let mut skip = 0; |
| |
| for k in 0..7 { |
| if k == 6 { |
| skip = 1; |
| } |
| if info & (1 << (14 - k)) == 0 { |
| self.set(k + skip, 8); |
| self.set(8, self.width - 1 - k); |
| } |
| } |
| skip = 0; |
| for k in 0..8 { |
| if k == 2 { |
| skip = 1; |
| } |
| if info & (1 << (7 - k)) == 0 { |
| self.set(8, 8 - skip - k); |
| self.set(self.width - 8 + k, 8); |
| } |
| } |
| } |
| |
| fn is_maskinfo(&self, x: u8, y: u8) -> bool { |
| let end = self.width - 8; |
| // Count the dark module as mask info. |
| (x <= 8 && y == 8) || (y <= 8 && x == 8) || (x == 8 && y >= end) || (x >= end && y == 8) |
| } |
| |
| // Version info: 18bits written twice, close to the finders. |
| fn draw_version_info(&mut self) { |
| let vinfo = self.version.version_info(); |
| let pos = self.width - 11; |
| |
| if vinfo != 0 { |
| for x in 0..3 { |
| for y in 0..6 { |
| if vinfo & (1 << (x + y * 3)) == 0 { |
| self.set(x + pos, y); |
| self.set(y, x + pos); |
| } |
| } |
| } |
| } |
| } |
| |
| fn is_version_info(&self, x: u8, y: u8) -> bool { |
| let vinfo = self.version.version_info(); |
| let pos = self.width - 11; |
| |
| vinfo != 0 && ((x >= pos && x < pos + 3 && y < 6) || (y >= pos && y < pos + 3 && x < 6)) |
| } |
| |
| // Returns true if the module is reserved (Not usable for data and EC). |
| fn is_reserved(&self, x: u8, y: u8) -> bool { |
| self.is_alignment(x, y) |
| || self.is_finder(x, y) |
| || self.is_timing(x, y) |
| || self.is_maskinfo(x, y) |
| || self.is_version_info(x, y) |
| } |
| |
| // Last module to draw, at bottom left corner. |
| fn is_last(&self, x: u8, y: u8) -> bool { |
| x == 0 && y == self.width - 1 |
| } |
| |
| // Move to the next module according to QR code order. |
| // From bottom right corner, to bottom left corner. |
| fn next(&self, x: u8, y: u8) -> (u8, u8) { |
| let x_adj = if x <= 6 { x + 1 } else { x }; |
| let column_type = (self.width - x_adj) % 4; |
| |
| match column_type { |
| 2 if y > 0 => (x + 1, y - 1), |
| 0 if y < self.width - 1 => (x + 1, y + 1), |
| 0 | 2 if x == 7 => (x - 2, y), |
| _ => (x - 1, y), |
| } |
| } |
| |
| // Find next module that can hold data. |
| fn next_available(&self, x: u8, y: u8) -> (u8, u8) { |
| let (mut x, mut y) = self.next(x, y); |
| while self.is_reserved(x, y) && !self.is_last(x, y) { |
| (x, y) = self.next(x, y); |
| } |
| (x, y) |
| } |
| |
| fn draw_data(&mut self, data: impl Iterator<Item = u8>) { |
| let (mut x, mut y) = (self.width - 1, self.width - 1); |
| for byte in data { |
| for s in 0..8 { |
| if byte & (0x80 >> s) == 0 { |
| self.set(x, y); |
| } |
| (x, y) = self.next_available(x, y); |
| } |
| } |
| // Set the remaining modules (0, 3 or 7 depending on version). |
| // because 0 correspond to a light module. |
| while !self.is_last(x, y) { |
| if !self.is_reserved(x, y) { |
| self.set(x, y); |
| } |
| (x, y) = self.next(x, y); |
| } |
| } |
| |
| // Apply checkerboard mask to all non-reserved modules. |
| fn apply_mask(&mut self) { |
| for x in 0..self.width { |
| for y in 0..self.width { |
| if (x ^ y) % 2 == 0 && !self.is_reserved(x, y) { |
| self.xor(x, y); |
| } |
| } |
| } |
| } |
| |
| // Draw the QR code with the provided data iterator. |
| fn draw_all(&mut self, data: impl Iterator<Item = u8>) { |
| // First clear the table, as it may have already some data. |
| self.clear(); |
| self.draw_finders(); |
| self.draw_alignments(); |
| self.draw_timing_patterns(); |
| self.draw_version_info(); |
| self.draw_data(data); |
| self.draw_maskinfo(); |
| self.apply_mask(); |
| } |
| } |
| |
| /// C entry point for the rust QR Code generator. |
| /// |
| /// Write the QR code image in the data buffer, and return the QR code width, |
| /// or 0, if the data doesn't fit in a QR code. |
| /// |
| /// * `url`: The base URL of the QR code. It will be encoded as Binary segment. |
| /// * `data`: A pointer to the binary data, to be encoded. if URL is NULL, it |
| /// will be encoded as binary segment, otherwise it will be encoded |
| /// efficiently as a numeric segment, and appended to the URL. |
| /// * `data_len`: Length of the data, that needs to be encoded, must be less |
| /// than data_size. |
| /// * `data_size`: Size of data buffer, it should be at least 4071 bytes to hold |
| /// a V40 QR code. It will then be overwritten with the QR code image. |
| /// * `tmp`: A temporary buffer that the QR code encoder will use, to write the |
| /// segments and ECC. |
| /// * `tmp_size`: Size of the temporary buffer, it must be at least 3706 bytes |
| /// long for V40. |
| /// |
| /// # Safety |
| /// |
| /// * `url` must be null or point at a nul-terminated string. |
| /// * `data` must be valid for reading and writing for `data_size` bytes. |
| /// * `tmp` must be valid for reading and writing for `tmp_size` bytes. |
| /// |
| /// They must remain valid for the duration of the function call. |
| |
| #[no_mangle] |
| pub unsafe extern "C" fn drm_panic_qr_generate( |
| url: *const i8, |
| data: *mut u8, |
| data_len: usize, |
| data_size: usize, |
| tmp: *mut u8, |
| tmp_size: usize, |
| ) -> u8 { |
| if data_size < 4071 || tmp_size < 3706 || data_len > data_size { |
| return 0; |
| } |
| // SAFETY: The caller ensures that `data` is a valid pointer for reading and |
| // writing `data_size` bytes. |
| let data_slice: &mut [u8] = unsafe { core::slice::from_raw_parts_mut(data, data_size) }; |
| // SAFETY: The caller ensures that `tmp` is a valid pointer for reading and |
| // writing `tmp_size` bytes. |
| let tmp_slice: &mut [u8] = unsafe { core::slice::from_raw_parts_mut(tmp, tmp_size) }; |
| if url.is_null() { |
| match EncodedMsg::new(&[&Segment::Binary(&data_slice[0..data_len])], tmp_slice) { |
| None => 0, |
| Some(em) => { |
| let qr_image = QrImage::new(&em, data_slice); |
| qr_image.width |
| } |
| } |
| } else { |
| // SAFETY: The caller ensures that `url` is a valid pointer to a |
| // nul-terminated string. |
| let url_cstr: &CStr = unsafe { CStr::from_char_ptr(url) }; |
| let segments = &[ |
| &Segment::Binary(url_cstr.as_bytes()), |
| &Segment::Numeric(&data_slice[0..data_len]), |
| ]; |
| match EncodedMsg::new(segments, tmp_slice) { |
| None => 0, |
| Some(em) => { |
| let qr_image = QrImage::new(&em, data_slice); |
| qr_image.width |
| } |
| } |
| } |
| } |
| |
| /// Returns the maximum data size that can fit in a QR code of this version. |
| /// * `version`: QR code version, between 1-40. |
| /// * `url_len`: Length of the URL. |
| /// |
| /// * If `url_len` > 0, remove the 2 segments header/length and also count the |
| /// conversion to numeric segments. |
| /// * If `url_len` = 0, only removes 3 bytes for 1 binary segment. |
| #[no_mangle] |
| pub extern "C" fn drm_panic_qr_max_data_size(version: u8, url_len: usize) -> usize { |
| if version < 1 || version > 40 { |
| return 0; |
| } |
| let max_data = Version(version as usize).max_data(); |
| |
| if url_len > 0 { |
| // Binary segment (URL) 4 + 16 bits, numeric segment (kmsg) 4 + 12 bits => 5 bytes. |
| if url_len + 5 >= max_data { |
| 0 |
| } else { |
| let max = max_data - url_len - 5; |
| (max * 39) / 40 |
| } |
| } else { |
| // Remove 3 bytes for the binary segment (header 4 bits, length 16 bits, stop 4bits). |
| max_data - 3 |
| } |
| } |
