bigint_expmod_u(data, data, key->exponent, key->modulus);
}
-void rsa_dec(bigint_t* data, rsa_privatekey_t* key){
- bigint_expmod_u(data, data, key->exponent, key->modulus);
+/*
+(p,q,dp,dq,qinv)
+m1 = c**dp % p
+m2 = c**dq % q
+h = (m1 - m2) * qinv % p
+m = m2 + q * h
+*/
+
+uint8_t rsa_dec_crt_mono(bigint_t* data, rsa_privatekey_t* key){
+ bigint_t m1, m2;
+ m1.wordv = malloc(key->components[0]->length_B * sizeof(bigint_word_t));
+ m2.wordv = malloc(key->components[1]->length_B * sizeof(bigint_word_t));
+ if(!m1.wordv || !m2.wordv){
+ free(m1.wordv);
+ free(m2.wordv);
+ return 1;
+ }
+ bigint_expmod_u(&m1, data, key->components[2], key->components[0]);
+ bigint_expmod_u(&m2, data, key->components[3], key->components[1]);
+ bigint_sub_s(&m1, &m1, &m2);
+ while(BIGINT_NEG_MASK & m1.info){
+ bigint_add_s(&m1, &m1, key->components[0]);
+ }
+ bigint_reduce(&m1, key->components[0]);
+ bigint_mul_u(data, &m1, key->components[4]);
+ bigint_reduce(data, key->components[0]);
+ bigint_mul_u(data, data, key->components[1]);
+ bigint_add_u(data, data, &m2);
+ free(m1.wordv);
+ free(m2.wordv);
+ return 0;
+}
+
+uint8_t rsa_dec(bigint_t* data, rsa_privatekey_t* key){
+ if(key->n == 1){
+ bigint_expmod_u(data, data, key->components[0], key->modulus);
+ return 0;
+ }
+ if(key->n == 5){
+ if (rsa_dec_crt_mono(data, key)){
+ return 3;
+ }
+ return 0;
+ }
+ if(key->n<8 || (key->n-5)%3 != 0){
+ return 1;
+ }
+ //rsa_dec_crt_multi(data, key, (key->n-5)/3);
+ return 2;
}
void rsa_os2ip(bigint_t* dest, const void* data, uint32_t length_B){