Add 64-bit integer support to ASN.1 compiler

ASN.1 INTEGERs will now compile to C int64_t or uint64_t, depending
    on whether the constraint ranges include numbers that cannot be
    represented in 32-bit ints and whether they include negative
    numbers.

    Template backend support included.  check-template is now built with
    --template, so we know we're testing it.

    Tests included.

lib/asn1/der_put.c

@@ -75,6 +75,38 @@ der_put_unsigned (unsigned char *p, size_t len, const unsigned *v, size_t *size)
     }
 }
 
+int
+der_put_unsigned64 (unsigned char *p, size_t len, const uint64_t *v, size_t *size)
+{
+    unsigned char *base = p;
+    uint64_t val = *v;
+
+    if (val) {
+	while (len > 0 && val) {
+	    *p-- = val % 256;
+	    val /= 256;
+	    --len;
+	}
+	if (val != 0)
+	    return ASN1_OVERFLOW;
+	else {
+	    if(p[1] >= 128) {
+		if(len < 1)
+		    return ASN1_OVERFLOW;
+		*p-- = 0;
+	    }
+	    *size = base - p;
+	    return 0;
+	}
+    } else if (len < 1)
+	return ASN1_OVERFLOW;
+    else {
+	*p    = 0;
+	*size = 1;
+	return 0;
+    }
+}
+
 int
 der_put_integer (unsigned char *p, size_t len, const int *v, size_t *size)
 {
@@ -115,6 +147,46 @@ der_put_integer (unsigned char *p, size_t len, const int *v, size_t *size)
     return 0;
 }
 
+int
+der_put_integer64 (unsigned char *p, size_t len, const int64_t *v, size_t *size)
+{
+    unsigned char *base = p;
+    int64_t val = *v;
+
+    if(val >= 0) {
+	do {
+	    if(len < 1)
+		return ASN1_OVERFLOW;
+	    *p-- = val % 256;
+	    len--;
+	    val /= 256;
+	} while(val);
+	if(p[1] >= 128) {
+	    if(len < 1)
+		return ASN1_OVERFLOW;
+	    *p-- = 0;
+	    len--;
+	}
+    } else {
+	val = ~val;
+	do {
+	    if(len < 1)
+		return ASN1_OVERFLOW;
+	    *p-- = ~(val % 256);
+	    len--;
+	    val /= 256;
+	} while(val);
+	if(p[1] < 128) {
+	    if(len < 1)
+		return ASN1_OVERFLOW;
+	    *p-- = 0xff;
+	    len--;
+	}
+    }
+    *size = base - p;
+    return 0;
+}
+
 
 int
 der_put_length (unsigned char *p, size_t len, size_t val, size_t *size)