From e5296441c98c35140f909ca1dbdb8d6852f996d3 Mon Sep 17 00:00:00 2001
From: bg <daniel.otte@rub.de>
Date: Wed, 4 Apr 2012 15:43:40 +0200
Subject: [PATCH] bug fixing(tm)
---
bigint/bigint.c | 2 +-
rsa/rsa_basic.c | 41 +++++++++++++++---
rsa/rsa_pkcs15.c | 42 +++++++++++++++++--
rsa/rsa_pkcs15.h | 4 ++
test_src/string-extras.c | 10 +++++
.../pkcs1v15crypt-vectors.txt | 0
6 files changed, 89 insertions(+), 10 deletions(-)
rename {rsa => testvectors/rsa-pkcs-1v2-1-vec}/pkcs1v15crypt-vectors.txt (100%)
diff --git a/bigint/bigint.c b/bigint/bigint.c
index a7a2b59..f0d7d6e 100644
--- a/bigint/bigint.c
+++ b/bigint/bigint.c
@@ -956,7 +956,7 @@ void bigint_inverse(bigint_t* dest, const bigint_t* a, const bigint_t* m){
void bigint_changeendianess(bigint_t* a){
uint8_t t, *p, *q;
p = (uint8_t*)(a->wordv);
- q = ((uint8_t*)p)+a->length_B*sizeof(bigint_word_t)-1;
+ q = p + a->length_B * sizeof(bigint_word_t) - 1;
while(p<q){
t = *p;
*p = *q;
diff --git a/rsa/rsa_basic.c b/rsa/rsa_basic.c
index e71bc8c..a166dfa 100644
--- a/rsa/rsa_basic.c
+++ b/rsa/rsa_basic.c
@@ -29,6 +29,7 @@
#if DEBUG
#include "cli.h"
#include "uart_lowlevel.h"
+#include "string-extras.h"
#endif
void rsa_enc(bigint_t* data, rsa_publickey_t* key){
@@ -108,8 +109,18 @@ uint8_t rsa_dec(bigint_t* data, rsa_privatekey_t* key){
}
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_B = 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);
@@ -117,19 +128,36 @@ 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_B = (length_B + off) / sizeof(bigint_word_t);
+#if DEBUG
+ cli_putstr("\r\nDBG: dest->length_B = 0x");
+ cli_hexdump_rev(&(dest->length_B), 2);
+#endif
+#endif
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_B;
+ uint16_t i;
+ for(i=src->length_B; i>0; --i){
+ *((uint8_t*)dest) = *--e;
+ dest = (uint8_t*)dest + 1;
+ }
+ }else{
+ bigint_changeendianess(src);
+ }
+
+ *out_length_B = src->length_B;
+#else
*out_length_B = bigint_get_first_set_bit(src) / 8 + 1;
if(dest){
uint16_t i;
@@ -147,5 +175,6 @@ 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
}
diff --git a/rsa/rsa_pkcs15.c b/rsa/rsa_pkcs15.c
index 858b918..1db7d3f 100644
--- a/rsa/rsa_pkcs15.c
+++ b/rsa/rsa_pkcs15.c
@@ -32,11 +32,15 @@
#include "random_dummy.h"
+uint16_t rsa_pkcs15_compute_padlength_B(bigint_t* modulus, uint16_t msg_length_B){
+ return bigint_get_first_set_bit(modulus) / 8 + 1 - msg_length_B - 3;
+}
+
uint8_t rsa_encrypt_pkcs15(void* dest, uint16_t* out_length, const void* src,
uint16_t length_B, rsa_publickey_t* key, const void* pad){
int16_t pad_length;
bigint_t x;
- pad_length = (bigint_get_first_set_bit(key->modulus) + 7) / 8 - length_B - 3;
+ pad_length = rsa_pkcs15_compute_padlength_B(key->modulus, length_B);
if(pad_length<8){
#if DEBUG
cli_putstr("\r\nERROR: pad_length<8; pad_length: ");
@@ -45,6 +49,9 @@ uint8_t rsa_encrypt_pkcs15(void* dest, uint16_t* out_length, const void* src,
return 2; /* message to long */
}
if(!pad){
+#if DEBUG
+ cli_putstr("\r\nauto-generating pad ...");
+#endif
uint16_t i;
uint8_t c;
for(i=0; i<pad_length; ++i){
@@ -54,6 +61,10 @@ uint8_t rsa_encrypt_pkcs15(void* dest, uint16_t* out_length, const void* src,
((uint8_t*)dest)[i+2] = c;
}
}else{
+#if DEBUG
+ cli_putstr("\r\nsupplied pad: ");
+ cli_hexdump_block(pad, pad_length, 4, 16);
+#endif
memcpy((uint8_t*)dest + 2, pad, pad_length);
}
((uint8_t*)dest)[0] = 0x00;
@@ -62,6 +73,10 @@ uint8_t rsa_encrypt_pkcs15(void* dest, uint16_t* out_length, const void* src,
memcpy((uint8_t*)dest+3+pad_length, src, length_B);
x.wordv = dest;
x.length_B = (length_B+pad_length+3+sizeof(bigint_word_t)-1)/sizeof(bigint_word_t);
+#if DEBUG
+ cli_putstr("\r\nx-data: ");
+ cli_hexdump_block(x.wordv, x.length_B * sizeof(bigint_word_t), 4, 16);
+#endif
bigint_adjust(&x);
rsa_os2ip(&x, NULL, length_B+pad_length+3);
rsa_enc(&x, key);
@@ -77,18 +92,30 @@ uint8_t rsa_decrypt_pkcs15(void* dest, uint16_t* out_length, const void* src,
rsa_os2ip(&x, src, length_B);
#if DEBUG
cli_putstr("\r\ncalling rsa_dec() ...");
+ cli_putstr("\r\nencoded block (src.len = 0x");
+ cli_hexdump_rev(&length_B, 2);
+ cli_putstr("):");
+ cli_hexdump_block(x.wordv, x.length_B * sizeof(bigint_word_t), 4, 16);
#endif
rsa_dec(&x, key);
#if DEBUG
cli_putstr("\r\nfinished rsa_dec() ...");
#endif
rsa_i2osp(NULL, &x, &m_length);
+#if DEBUG
+ cli_putstr("\r\ndecoded block:");
+ cli_hexdump_block(x.wordv, m_length, 4, 16);
+#endif
while(((uint8_t*)x.wordv)[idx]==0 && idx<m_length){
++idx;
}
- if(((uint8_t*)x.wordv)[idx]!=2 || idx>=m_length){
+ if(idx>=m_length){
return 1;
}
+ if(((uint8_t*)x.wordv)[idx]!=2){
+ return 3;
+ }
+
++idx;
while(((uint8_t*)x.wordv)[idx+pad_length]!=0 && (idx+pad_length)<m_length){
++pad_length;
@@ -98,9 +125,18 @@ uint8_t rsa_decrypt_pkcs15(void* dest, uint16_t* out_length, const void* src,
}
*out_length = m_length - idx - pad_length - 1;
if(pad){
+#if DEBUG
+ cli_putstr("\r\npadding block:");
+ cli_hexdump_block(((uint8_t*)x.wordv)+idx, pad_length, 4, 16);
+ cli_putstr("\r\npad @ 0x");
+ cli_hexdump_rev(&pad, 2);
+ cli_putstr("\r\ndst @ 0x");
+ cli_hexdump_rev(&dest, 2);
+#endif
memcpy(pad, ((uint8_t*)x.wordv)+idx, pad_length);
}
- memcpy(dest, ((uint8_t*)x.wordv) + idx + pad_length + 1, m_length - idx - pad_length - 1);
+ memmove(dest, ((uint8_t*)x.wordv) + idx + pad_length + 1, m_length - idx - pad_length - 1);
+
return 0;
}
diff --git a/rsa/rsa_pkcs15.h b/rsa/rsa_pkcs15.h
index 74180dd..ff1b26d 100644
--- a/rsa/rsa_pkcs15.h
+++ b/rsa/rsa_pkcs15.h
@@ -21,6 +21,10 @@
#define RSA_PKCS15_H_
#include <stdint.h>
+#include "bigint.h"
+
+uint16_t rsa_pkcs15_compute_padlength_B(bigint_t* modulus, uint16_t msg_length_B);
+
uint8_t rsa_encrypt_pkcs15(void* dest, uint16_t* out_length, const void* src,
uint16_t length_B, rsa_publickey_t* key, const void* pad);
diff --git a/test_src/string-extras.c b/test_src/string-extras.c
index 18cf67f..6ab077e 100644
--- a/test_src/string-extras.c
+++ b/test_src/string-extras.c
@@ -40,6 +40,7 @@ uint32_t stridentcnt(const char* a, const char* b){
a++;
b++;
}
+ return 0;
}
uint16_t firstword_length(const char* s){
@@ -155,3 +156,12 @@ void strlwr(char* s){
}
}
*/
+
+char* itoa(int a, char* buffer, uint8_t radix){
+ if(a<0){
+ *buffer = '-';
+ a = -a;
+ }
+ ultoa(a, buffer + 1, radix);
+ return buffer;
+}
diff --git a/rsa/pkcs1v15crypt-vectors.txt b/testvectors/rsa-pkcs-1v2-1-vec/pkcs1v15crypt-vectors.txt
similarity index 100%
rename from rsa/pkcs1v15crypt-vectors.txt
rename to testvectors/rsa-pkcs-1v2-1-vec/pkcs1v15crypt-vectors.txt
--
2.39.5