uses crc16-ccitt logic to create field crc16

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "brcode"
-version = "1.0.1"
+version = "1.1.0"
 authors = ["Julia Naomi <[email protected]>"]
 edition = "2018"
 description = "Crate to parse and emit BR Codes"
@@ -37,4 +37,8 @@ harness = false
 
 [[bench]]
 name = "both_ways"
+harness = false
+
+[[bench]]
+name = "crc16"
 harness = false

README.md

@@ -1,12 +1,14 @@
 # BR Code
 
 A crate to parse and emit [PIX BR Code](https://www.bcb.gov.br/content/estabilidadefinanceira/spb_docs/ManualBRCode.pdf).
+* [Technical and Business specs for BR Code usage](https://www.bcb.gov.br/content/estabilidadefinanceira/forumpireunioes/Anexo%20I%20-%20QRCodes%20-%20Especifica%C3%A7%C3%A3o%20-%20vers%C3%A3o%201-1.pdf)
+
 
 ## Usage
 
 ```toml
 [dependencies]
-brcode = "1.0.1"
+brcode = "1.1.0"
 ```
 
 Shellscript to get files from release:
@@ -483,6 +485,11 @@ time:   [33.238 us 33.555 us 33.924 us]
 time:   [24.537 us 25.391 us 26.260 us] 
 ```
 
+**crc16_ccitt** in `benches/crc16`:
+```
+time:   [3.0738 us 3.0825 us 3.0938 us]
+```
+
 ## Goals
 - [x] Parse BR Code String;
 - [x] Parse BR Code to `BrCode` struct;

benches/crc16.rs

@@ -0,0 +1,15 @@
+use brcode::crc16_ccitt;
+use criterion::{criterion_group, criterion_main, Criterion};
+
+fn criterion_benchmark(c: &mut Criterion) {
+    let message = message();
+    c.bench_function("crc16", |b| b.iter(|| crc16_ccitt(&message)));
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);
+
+fn message() -> String {
+    "00020104141234567890123426580014BR.GOV.BCB.PIX0136123e4567-e12b-12d1-a456-42665544000027300012BR.COM.OUTRO011001234567895204000053039865406123.455802BR5917NOME DO RECEBEDOR6008BRASILIA61087007490062190515RP12345678-201980390012BR.COM.OUTRO01190123.ABCD.3456.WXYZ6304"
+    .to_string()
+}

src/aux.rs

@@ -51,6 +51,29 @@ impl FromIterator<(usize, parse::Data)> for HashBrCode {
     }
 }
 
+pub fn crc16_ccitt(message: &str) -> String {
+    let mut crc: u16 = 0xFFFF;          // initial value
+    let polynomial: u16 = 0x1021;   // 0001 0000 0010 0001  (0, 5, 12) 
+
+    // byte[] testBytes = "123456789".getBytes("ASCII");
+
+    let bytes = message.as_bytes();
+
+    for b in bytes {
+        for i in 0u16..8u16 {
+            let bit = (b   >> (7-i) & 1) == 1;
+            let c15 = (crc >> 15    & 1) == 1;
+            crc <<= 1;
+            if c15 ^ bit {crc ^= polynomial};
+        }
+    }
+
+    crc &= 0xffff;
+
+
+    format!("{:X}", crc)
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -71,6 +94,14 @@ mod test {
         assert_eq!(hash.0, expected);
     }
 
+    #[test]
+    fn test_crc16_ccitt() {
+        let crc16 = crc16_ccitt("123456789");
+        let expected = "29B1";
+
+        assert_eq!(crc16, expected);
+    }
+
     #[test]
     fn creates_nested_map() {
         let vec = vec![

src/lib.rs

@@ -5,6 +5,7 @@ pub(crate) mod parse;
 
 pub use model::{BrCode, Info, Label, MerchantInfo, Template};
 pub use parse::Data;
+pub use aux::crc16_ccitt;
 
 pub fn from_str(code: &str) -> Vec<(usize, parse::Data)> {
     parse::parse(code, 99)

src/model.rs

@@ -179,10 +179,11 @@ impl BrCode {
                 m.info.iter().for_each(|i| {
                     encode.push_str(&format!("{:02}{:02}{}", i.id, i.info.len(), i.info));
                 });
-            }), //TODO
+            }),
         }
-        encode.push_str(&format!("6304{:04}", self.crc1610));
-
+        encode.push_str("6304");
+        let crc16 = crate::aux::crc16_ccitt(&encode);
+        encode.push_str(&crc16);
         encode
     }
 }

tests/lib.rs

@@ -16,6 +16,14 @@ fn test_to_string() {
     assert_eq!(actual, expected);
 }
 
+#[test]
+fn assert_both_ways() {
+    let from = brcode::from_str(&dynamic_code());
+    let to = brcode::to_string(from);
+
+    assert_eq!(to, dynamic_code())
+}
+
 #[test]
 fn test_brcode_to_string() {
     let actual = brcode::brcode_to_string(brcode_expected());
@@ -77,6 +85,11 @@ fn json_to_brcode_ffi() {
     assert_eq!(actual, code);
 }
 
+fn dynamic_code() -> String {
+    "00020101021226740014br.gov.bcb.spi210812345678220412342308123456782420001122334455667788995204000053039865406123.455802BR5913FULANO DE TAL6008BRASILIA62190515RP12345678-201980720014br.gov.bcb.spi2550bx.com.br/spi/U0VHUkVET1RPVEFMTUVOVEVBTEVBVE9SSU8=630434D1"
+    .to_string()
+}
+
 fn code() -> String {
     "00020104141234567890123426580014BR.GOV.BCB.PIX0136123e4567-e12b-12d1-a456-42665544000027300012BR.COM.OUTRO011001234567895204000053039865406123.455802BR5917NOME DO RECEBEDOR6008BRASILIA61087007490062190515RP12345678-201980390012BR.COM.OUTRO01190123.ABCD.3456.WXYZ6304AD38"
     .to_string()