feat: add rsa

src/main.rs

@@ -6,6 +6,8 @@ use rust_util::util_clap::{Command, CommandError};
 
 mod fido;
 mod digest;
+#[allow(unused)] // pending use in pgpcardimport
+mod rsautil;
 mod pkiutil;
 mod pgpcardutil;
 mod cmd_u2fregister;

src/rsautil.rs

@@ -0,0 +1,67 @@
+use openssl::bn::{BigNum, BigNumContext};
+use rust_util::XResult;
+
+#[derive(Debug)]
+pub struct RsaCrt {
+    // n = p * q
+    pub modulus: BigNum,
+    // e
+    pub public_exponent: BigNum,
+    // d = e mod inverse ((p - 1) * (q - 1))
+    pub private_exponent: BigNum,
+    // p
+    pub prime1: BigNum,
+    // q
+    pub prime2: BigNum,
+    // dp = d mod (p−1)
+    pub exponent1: BigNum,
+    // dq = d mod (q−1)
+    pub exponent2: BigNum,
+    // qinv = q^−1 mod p
+    pub coefficient: BigNum,
+}
+
+impl RsaCrt {
+    pub fn from(p: BigNum, q: BigNum, e: BigNum) -> XResult<RsaCrt> {
+        Ok(opt_result!( inner_from(p, q, e), "Calc RsaCrt failed: {}"))
+    }
+}
+
+pub fn clone_big_num(n: &BigNum) -> XResult<BigNum> {
+    Ok(opt_result!(BigNum::from_slice(n.to_vec().as_slice()), "Clone big num:{}, failed: {}", n))
+}
+
+fn inner_from(p: BigNum, q: BigNum, e: BigNum) -> XResult<RsaCrt> {
+    let mut n = BigNum::new()?;
+    n.checked_mul(&p, &q, &mut BigNumContext::new().unwrap())?;
+
+    let mut p_m1 = clone_big_num(&p)?;
+    p_m1.sub_word(1)?;
+    let mut q_m1 = clone_big_num(&q)?;
+    q_m1.sub_word(1)?;
+    let mut m = BigNum::new()?;
+    m.checked_mul(&p_m1, &q_m1, &mut BigNumContext::new().unwrap())?;
+
+    let mut d = BigNum::new()?;
+    d.mod_inverse(&e, &m, &mut BigNumContext::new().unwrap())?;
+
+    let mut dp = BigNum::new()?;
+    dp.nnmod(&d, &p_m1, &mut BigNumContext::new().unwrap())?;
+
+    let mut dq = BigNum::new()?;
+    dq.nnmod(&d, &q_m1, &mut BigNumContext::new().unwrap())?;
+
+    let mut qinv = BigNum::new()?;
+    qinv.mod_inverse(&q, &p, &mut BigNumContext::new().unwrap())?;
+
+    Ok(RsaCrt {
+        modulus: n,
+        public_exponent: e,
+        private_exponent: d,
+        prime1: p,
+        prime2: q,
+        exponent1: dp,
+        exponent2: dq,
+        coefficient: qinv,
+    })
+}