Add mifare crypto trace decryption utility

[proxmark3-svn] / armsrc / des.c

diff --git a/armsrc/des.c b/armsrc/des.c
index dbe62da995ba5107854ef38ed476d2ca469fc16a..a81df9c8d4234c7bd2bd5432b0a503f9a1c6ba36 100644 (file)
--- a/armsrc/des.c
+++ b/armsrc/des.c
@@ -378,38 +378,53 @@ void tdes_dec(void* out, void* in, const uint8_t* key){
        des_dec(out, out, (uint8_t*)key + 0);
 }
 
-void tdes_2key_enc(void* out, const void* in, size_t length, const void* key){
+void tdes_2key_enc(void* out, const void* in, size_t length, const void* key, unsigned char iv[8]){
 
        if( length % 8 ) return; 
        
+       uint8_t i;
        uint8_t* tin = (uint8_t*) in;
        uint8_t* tout = (uint8_t*) out;
        
        while( length > 0 )
        {
+               for ( i = 0; i < 8; i++ )
+                       tout[i] = (unsigned char)(tin[i] ^ iv[i]);
+
                des_enc(tout,  tin, (uint8_t*)key + 0);
                des_dec(tout, tout, (uint8_t*)key + 8);
                des_enc(tout, tout, (uint8_t*)key + 0);
                
+               memcpy(iv, tout, 8);
+
                tin  += 8;
                tout += 8;
                length -= 8;
        }
 }
 
-void tdes_2key_dec(void* out, const void* in, size_t length, const void* key){
+void tdes_2key_dec(void* out, const void* in, size_t length, const void* key, unsigned char iv[8]){
        
        if( length % 8 ) return; 
 
+       uint8_t i;
+       unsigned char temp[8];
        uint8_t* tin = (uint8_t*) in;
        uint8_t* tout = (uint8_t*) out;
        
        while( length > 0 )
        {
+               memcpy(temp, tin, 8);
+
                des_dec(tout,  tin, (uint8_t*)key + 0);
                des_enc(tout, tout, (uint8_t*)key + 8);
                des_dec(tout, tout, (uint8_t*)key + 0);          
 
+               for (i = 0; i < 8; i++)
+                       tout[i] = (unsigned char)(tout[i] ^ iv[i]);
+
+               memcpy(iv, temp, 8);
+               
                tin  += 8;
                tout += 8;
                length -= 8;