PER-encoding of integers wider than 32 bits

3 files changed, 93 insertions, 37 deletions

diff --git a/skeletons/INTEGER.c b/skeletons/INTEGER.c
index 4dfe530a..9ce69604 100644
--- a/skeletons/INTEGER.c
+++ b/skeletons/INTEGER.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2003, 2004, 2005, 2006, 2007 Lev Walkin <vlm@lionet.info>.
+ * Copyright (c) 2003-2014 Lev Walkin <vlm@lionet.info>.
  * All rights reserved.
  * Redistribution and modifications are permitted subject to BSD license.
  */
@@ -595,30 +595,35 @@ INTEGER_decode_uper(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
 		}
 	}
 
-	/* X.691, #12.2.2 */
+	/* X.691-2008/11, #13.2.2, constrained whole number */
 	if(ct && ct->flags != APC_UNCONSTRAINED) {
-		/* #10.5.6 */
+		/* #11.5.6 */
 		ASN_DEBUG("Integer with range %d bits", ct->range_bits);
 		if(ct->range_bits >= 0) {
-			long value;
-			if(ct->range_bits == 32) {
-				long lhalf;
-				value = per_get_few_bits(pd, 16);
-				if(value < 0) _ASN_DECODE_STARVED;
-				lhalf = per_get_few_bits(pd, 16);
-				if(lhalf < 0) _ASN_DECODE_STARVED;
-				value = (value << 16) | lhalf;
+			if((size_t)ct->range_bits > 8 * sizeof(unsigned long))
+				_ASN_DECODE_FAILED;
+
+			if(specs && specs->field_unsigned) {
+				unsigned long uvalue;
+				if(uper_get_constrained_whole_number(pd,
+					&uvalue, ct->range_bits))
+					_ASN_DECODE_STARVED;
+				ASN_DEBUG("Got value %lu + low %ld",
+					uvalue, ct->lower_bound);
+				uvalue += ct->lower_bound;
+				if(asn_ulong2INTEGER(st, uvalue))
+					_ASN_DECODE_FAILED;
 			} else {
-				value = per_get_few_bits(pd, ct->range_bits);
-				if(value < 0) _ASN_DECODE_STARVED;
+				unsigned long svalue;
+				if(uper_get_constrained_whole_number(pd,
+					&svalue, ct->range_bits))
+					_ASN_DECODE_STARVED;
+				ASN_DEBUG("Got value %ld + low %ld",
+					svalue, ct->lower_bound);
+				svalue += ct->lower_bound;
+				if(asn_long2INTEGER(st, svalue))
+					_ASN_DECODE_FAILED;
 			}
-			ASN_DEBUG("Got value %ld + low %ld",
-				value, ct->lower_bound);
-			value += ct->lower_bound;
-			if((specs && specs->field_unsigned)
-				? asn_ulong2INTEGER(st, value)
-				: asn_long2INTEGER(st, value))
-				_ASN_DECODE_FAILED;
 			return rval;
 		}
 	} else {
@@ -725,22 +730,14 @@ INTEGER_encode_uper(asn_TYPE_descriptor_t *td,
 	}
 
 
-	/* X.691, #12.2.2 */
+	/* X.691-11/2008, #13.2.2, test if constrained whole number */
 	if(ct && ct->range_bits >= 0) {
-		/* #10.5.6 */
+		/* #11.5.6 -> #11.3 */
 		ASN_DEBUG("Encoding integer with range %d bits",
 			ct->range_bits);
-		if(ct->range_bits == 32) {
-			/* TODO: extend to >32 bits */
-			long v = value - ct->lower_bound;
-			if(per_put_few_bits(po, v >> 1, 31)
-			|| per_put_few_bits(po, v, 1))
-				_ASN_ENCODE_FAILED;
-		} else {
-			if(per_put_few_bits(po, value - ct->lower_bound,
-				ct->range_bits))
-				_ASN_ENCODE_FAILED;
-		}
+		long v = value - ct->lower_bound;
+		if(uper_put_constrained_whole_number_s(po, v, ct->range_bits))
+			_ASN_ENCODE_FAILED;
 		_ASN_ENCODED_OK(er);
 	}
 
diff --git a/skeletons/per_support.c b/skeletons/per_support.c
index 2481fffb..0d089f49 100644
--- a/skeletons/per_support.c
+++ b/skeletons/per_support.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2006, 2007 Lev Walkin <vlm@lionet.info>.
+ * Copyright (c) 2005-2014 Lev Walkin <vlm@lionet.info>.
  * All rights reserved.
  * Redistribution and modifications are permitted subject to BSD license.
  */
@@ -238,8 +238,8 @@ uper_get_nsnnwn(asn_per_data_t *pd) {
 }
 
 /*
- * Put the normally small non-negative whole number.
- * X.691, #10.6
+ * X.691-11/2008, #11.6
+ * Encoding of a normally small non-negative whole number
  */
 int
 uper_put_nsnnwn(asn_per_outp_t *po, int n) {
@@ -264,6 +264,58 @@ uper_put_nsnnwn(asn_per_outp_t *po, int n) {
 }
 
 
+/* X.691-2008/11, #11.5.6 -> #11.3 */
+int uper_get_constrained_whole_number(asn_per_data_t *pd, unsigned long *out_value, int nbits) {
+	unsigned long lhalf;    /* Lower half of the number*/
+	long half;
+
+	if(nbits <= 31) {
+		half = per_get_few_bits(pd, nbits);
+		if(half < 0) return -1;
+		*out_value = half;
+		return 0;
+	}
+
+	if((size_t)nbits > 8 * sizeof(*out_value))
+		return -1;  /* RANGE */
+
+	half = per_get_few_bits(pd, 31);
+	if(half < 0) return -1;
+
+	if(uper_get_constrained_whole_number(pd, &lhalf, nbits - 31))
+		return -1;
+
+	*out_value = ((unsigned long)half << (nbits - 31)) | lhalf;
+	return 0;
+}
+
+
+/* X.691-2008/11, #11.5.6 -> #11.3 */
+int uper_put_constrained_whole_number_s(asn_per_outp_t *po, long v, int nbits) {
+	/*
+	 * Assume signed number can be safely coerced into
+	 * unsigned of the same range.
+	 * The following testing code will likely be optimized out
+	 * by compiler if it is true.
+	 */
+	unsigned long uvalue1 = ULONG_MAX;
+	         long svalue  = uvalue1;
+	unsigned long uvalue2 = svalue;
+	assert(uvalue1 == uvalue2);
+	return uper_put_constrained_whole_number_u(po, v, nbits);
+}
+
+int uper_put_constrained_whole_number_u(asn_per_outp_t *po, unsigned long v, int nbits) {
+	if(nbits <= 31) {
+		return per_put_few_bits(po, v, nbits);
+	} else {
+		/* Put higher portion first, followed by lower 31-bit */
+		if(uper_put_constrained_whole_number_u(po, v >> 31, nbits - 31))
+			return -1;
+		return per_put_few_bits(po, v, 31);
+	}
+}
+
 /*
  * Put a small number of bits (<= 31).
  */
diff --git a/skeletons/per_support.h b/skeletons/per_support.h
index 7cb1a0ca..10c84ed0 100644
--- a/skeletons/per_support.h
+++ b/skeletons/per_support.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2006, 2007 Lev Walkin <vlm@lionet.info>.
+ * Copyright (c) 2005-2014 Lev Walkin <vlm@lionet.info>.
  * All rights reserved.
  * Redistribution and modifications are permitted subject to BSD license.
  */
@@ -81,6 +81,9 @@ ssize_t uper_get_nslength(asn_per_data_t *pd);
  */
 ssize_t uper_get_nsnnwn(asn_per_data_t *pd);
 
+/* X.691-2008/11, #11.5.6 */
+int uper_get_constrained_whole_number(asn_per_data_t *pd, unsigned long *v, int nbits);
+
 /* Non-thread-safe debugging function, don't use it */
 char *per_data_string(asn_per_data_t *pd);
 
@@ -103,6 +106,10 @@ int per_put_few_bits(asn_per_outp_t *per_data, uint32_t bits, int obits);
 /* Output a large number of bits */
 int per_put_many_bits(asn_per_outp_t *po, const uint8_t *src, int put_nbits);
 
+/* X.691-2008/11, #11.5 */
+int uper_put_constrained_whole_number_s(asn_per_outp_t *po, long v, int nbits);
+int uper_put_constrained_whole_number_u(asn_per_outp_t *po, unsigned long v, int nbits);
+
 /*
  * Put the length "n" to the Unaligned PER stream.
  * This function returns the number of units which may be flushed