X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=rsa%2Frsa_basic.c;h=e3687de17bfc0381bf67d45134904ce8c2361e69;hb=d8591851c323b773f2bb15ccc59d61c6a8ad3e89;hp=3e536b8cbf78bce230a13bbb6550c4e342e50e4f;hpb=3edc70ba3f2306ec503fb5e99858d28659dcac65;p=arm-crypto-lib.git

diff --git a/rsa/rsa_basic.c b/rsa/rsa_basic.c
index 3e536b8..e3687de 100644
--- 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
 }