a

libsec/desCBC.c

@@ -0,0 +1,59 @@
+#include "os.h"
+#include <mp.h>
+#include <libsec.h>
+
+// Because of the way that non multiple of 8
+// buffers are handled, the decryptor must
+// be fed buffers of the same size as the
+// encryptor
+
+
+// If the length is not a multiple of 8, I encrypt
+// the overflow to be compatible with lacy's cryptlib
+void
+desCBCencrypt(uchar *p, int len, DESstate *s)
+{
+	uchar *p2, *ip, *eip;
+
+	for(; len >= 8; len -= 8){
+		p2 = p;
+		ip = s->ivec;
+		for(eip = ip+8; ip < eip; )
+			*p2++ ^= *ip++;
+		block_cipher(s->expanded, p, 0);
+		memmove(s->ivec, p, 8);
+		p += 8;
+	}
+
+	if(len > 0){
+		ip = s->ivec;
+		block_cipher(s->expanded, ip, 0);
+		for(eip = ip+len; ip < eip; )
+			*p++ ^= *ip++;
+	}
+}
+
+void
+desCBCdecrypt(uchar *p, int len, DESstate *s)
+{
+	uchar *ip, *eip, *tp;
+	uchar tmp[8];
+
+	for(; len >= 8; len -= 8){
+		memmove(tmp, p, 8);
+		block_cipher(s->expanded, p, 1);
+		tp = tmp;
+		ip = s->ivec;
+		for(eip = ip+8; ip < eip; ){
+			*p++ ^= *ip;
+			*ip++ = *tp++;
+		}
+	}
+
+	if(len > 0){
+		ip = s->ivec;
+		block_cipher(s->expanded, ip, 0);
+		for(eip = ip+len; ip < eip; )
+			*p++ ^= *ip++;
+	}
+}