also from the length_B -> length_W migration

[arm-crypto-lib.git] / rsa / rsa_basic.c

diff --git a/rsa/rsa_basic.c b/rsa/rsa_basic.c
index 3e536b8cbf78bce230a13bbb6550c4e342e50e4f..e3687de17bfc0381bf67d45134904ce8c2361e69 100644 (file)
--- a/rsa/rsa_basic.c
+++ b/rsa/rsa_basic.c
@@ -21,21 +21,106 @@
 #include <stdlib.h>
 #include <string.h>
 #include "bigint.h"
+#include "bigint_io.h"
 #include "rsa_basic.h"
 
+#define DEBUG 0
+
+#if DEBUG
 #include "cli.h"
+#include "uart_lowlevel.h"
+#include "string-extras.h"
+#endif
 
-void rsa_enc(bigint_t* data, rsa_publickey_t* key){
-       bigint_expmod_u(data, data, key->exponent, key->modulus);
+void rsa_enc(bigint_t* data, const rsa_publickey_t* key){
+/*
+       cli_putstr("\r\n -->rsa_enc()\r\n m = ");
+       bigint_print_hex(data);
+       cli_putstr("\r\n e = ");
+       bigint_print_hex(key->exponent);
+       cli_putstr("\r\n n = ");
+       bigint_print_hex(key->modulus);
+*/
+       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, const rsa_privatekey_t* key){
+       bigint_t m1, m2;
+       m1.wordv = malloc(key->components[0].length_W * sizeof(bigint_word_t));
+       m2.wordv = malloc(key->components[1].length_W * sizeof(bigint_word_t));
+       if(!m1.wordv || !m2.wordv){
+#if DEBUG
+               cli_putstr("\r\nERROR: OOM!");
+#endif
+               free(m2.wordv);
+               free(m1.wordv);
+               return 1;
+       }
+#if DEBUG
+       cli_putstr("\r\nDBG: expmod m1 ...");
+#endif
+       bigint_expmod_u(&m1, data, &key->components[2], &key->components[0]);
+#if DEBUG
+       cli_putstr("expmod m2 ...");
+#endif
+       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]);
+       }
+
+#if DEBUG
+       cli_putstr("\r\nDBG: reduce-mul ...");
+#endif
+       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(m2.wordv);
+       free(m1.wordv);
+       return 0;
+}
+
+uint8_t rsa_dec(bigint_t* data, const 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){
+#if BIGINT_WORD_SIZE == 8
+       if(data){
+               memcpy(dest->wordv, data, length_B)
+       }
+       dest->length_W = length_B;
+#else
        uint8_t off;
-       off = length_B % sizeof(bigint_word_t);
+       off = (sizeof(bigint_word_t) - length_B % sizeof(bigint_word_t)) % sizeof(bigint_word_t);
+#if DEBUG
+       cli_putstr("\r\nDBG: off = 0x");
+       cli_hexdump_byte(off);
+#endif
        if(!data){
                if(off){
                        dest->wordv = realloc(dest->wordv, length_B + sizeof(bigint_word_t) - off);
@@ -43,19 +128,37 @@ void rsa_os2ip(bigint_t* dest, const void* data, uint32_t length_B){
                        memset(dest->wordv, 0, off);
                }
        }else{
+               memcpy((uint8_t*)dest->wordv + off, data, length_B);
                if(off){
-                       memcpy((uint8_t*)dest->wordv + off, data, length_B);
-                       memset(dest, 0, off);
-               }else{
-                       memcpy(dest->wordv, data, length_B);
+                       memset(dest->wordv, 0, off);
                }
        }
-       dest->length_B = (length_B + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
+       dest->length_W = (length_B + off) / sizeof(bigint_word_t);
+#if DEBUG
+       cli_putstr("\r\nDBG: dest->length_W = 0x");
+       cli_hexdump_rev(&(dest->length_W), 2);
+#endif
+#endif
+       dest->info = 0;
        bigint_changeendianess(dest);
        bigint_adjust(dest);
 }
 
 void rsa_i2osp(void* dest, bigint_t* src, uint16_t* out_length_B){
+#if BIGINT_WORD_SIZE == 8
+       if(dest){
+               uint8_t *e = src->wordv + src->length_W;
+               uint16_t i;
+               for(i=src->length_W; i>0; --i){
+                       *((uint8_t*)dest) = *--e;
+                       dest = (uint8_t*)dest + 1;
+               }
+       }else{
+               bigint_changeendianess(src);
+       }
+
+       *out_length_B = src->length_W;
+#else
        *out_length_B = bigint_get_first_set_bit(src) / 8 + 1;
        if(dest){
                uint16_t i;
@@ -73,5 +176,6 @@ void rsa_i2osp(void* dest, bigint_t* src, uint16_t* out_length_B){
                        memmove(src->wordv, (uint8_t*)src->wordv+off, *out_length_B);
                }
        }
+#endif
 }