--- /dev/null
+/*
+ * Copyright (c) 2005-2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#include <asn_system.h>
+#include <asn_internal.h>
+#include <uper_support.h>
+
+/*
+ * X.691-201508 #10.9 General rules for encoding a length determinant.
+ * Get the optionally constrained length "n" from the stream.
+ */
+ssize_t
+uper_get_length(asn_per_data_t *pd, int ebits, size_t lower_bound,
+ int *repeat) {
+ ssize_t value;
+
+ *repeat = 0;
+
+ /* #11.9.4.1 Encoding if constrained (according to effective bits) */
+ if(ebits >= 0 && ebits <= 16) {
+ value = per_get_few_bits(pd, ebits);
+ if(value >= 0) value += lower_bound;
+ return value;
+ }
+
+ value = per_get_few_bits(pd, 8);
+ if((value & 0x80) == 0) { /* #11.9.3.6 */
+ return (value & 0x7F);
+ } else if((value & 0x40) == 0) { /* #11.9.3.7 */
+ /* bit 8 ... set to 1 and bit 7 ... set to zero */
+ value = ((value & 0x3f) << 8) | per_get_few_bits(pd, 8);
+ return value; /* potential -1 from per_get_few_bits passes through. */
+ } else if(value < 0) {
+ ASN_DEBUG("END of stream reached for PER");
+ return -1;
+ }
+ value &= 0x3f; /* this is "m" from X.691, #11.9.3.8 */
+ if(value < 1 || value > 4) {
+ return -1; /* Prohibited by #11.9.3.8 */
+ }
+ *repeat = 1;
+ return (16384 * value);
+}
+
+/*
+ * Get the normally small length "n".
+ * This procedure used to decode length of extensions bit-maps
+ * for SET and SEQUENCE types.
+ */
+ssize_t
+uper_get_nslength(asn_per_data_t *pd) {
+ ssize_t length;
+
+ ASN_DEBUG("Getting normally small length");
+
+ if(per_get_few_bits(pd, 1) == 0) {
+ length = per_get_few_bits(pd, 6) + 1;
+ if(length <= 0) return -1;
+ ASN_DEBUG("l=%d", (int)length);
+ return length;
+ } else {
+ int repeat;
+ length = uper_get_length(pd, -1, 0, &repeat);
+ if(length >= 0 && !repeat) return length;
+ return -1; /* Error, or do not support >16K extensions */
+ }
+}
+
+/*
+ * Get the normally small non-negative whole number.
+ * X.691, #10.6
+ */
+ssize_t
+uper_get_nsnnwn(asn_per_data_t *pd) {
+ ssize_t value;
+
+ value = per_get_few_bits(pd, 7);
+ if(value & 64) { /* implicit (value < 0) */
+ value &= 63;
+ value <<= 2;
+ value |= per_get_few_bits(pd, 2);
+ if(value & 128) /* implicit (value < 0) */
+ return -1;
+ if(value == 0)
+ return 0;
+ if(value >= 3)
+ return -1;
+ value = per_get_few_bits(pd, 8 * value);
+ return value;
+ }
+
+ return value;
+}
+
+/*
+ * 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) {
+ int bytes;
+
+ if(n <= 63) {
+ if(n < 0) return -1;
+ return per_put_few_bits(po, n, 7);
+ }
+ if(n < 256)
+ bytes = 1;
+ else if(n < 65536)
+ bytes = 2;
+ else if(n < 256 * 65536)
+ bytes = 3;
+ else
+ return -1; /* This is not a "normally small" value */
+ if(per_put_few_bits(po, bytes, 8))
+ return -1;
+
+ return per_put_few_bits(po, n, 8 * bytes);
+}
+
+
+/* X.691-2008/11, #11.5.6 -> #11.3 */
+int uper_get_constrained_whole_number(asn_per_data_t *pd, uintmax_t *out_value, int nbits) {
+ uintmax_t lhalf; /* Lower half of the number*/
+ intmax_t 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 = ((uintmax_t)half << (nbits - 31)) | lhalf;
+ return 0;
+}
+
+
+/* X.691-2008/11, #11.5.6 -> #11.3 */
+int
+uper_put_constrained_whole_number_u(asn_per_outp_t *po, uintmax_t 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);
+ }
+}
+
+/*
+ * X.691 (08/2015) #11.9 "General rules for encoding a length determinant"
+ * Put the length "n" (or part of it) into the stream.
+ */
+ssize_t
+uper_put_length(asn_per_outp_t *po, size_t length, int *need_eom) {
+ int dummy = 0;
+ if(!need_eom) need_eom = &dummy;
+
+ if(length <= 127) { /* #11.9.3.6 */
+ *need_eom = 0;
+ return per_put_few_bits(po, length, 8)
+ ? -1 : (ssize_t)length;
+ } else if(length < 16384) { /* #10.9.3.7 */
+ *need_eom = 0;
+ return per_put_few_bits(po, length|0x8000, 16)
+ ? -1 : (ssize_t)length;
+ }
+
+ *need_eom = 0 == (length & 16383);
+ length >>= 14;
+ if(length > 4) {
+ *need_eom = 0;
+ length = 4;
+ }
+
+ return per_put_few_bits(po, 0xC0 | length, 8)
+ ? -1 : (ssize_t)(length << 14);
+
+}
+
+
+/*
+ * Put the normally small length "n" into the stream.
+ * This procedure used to encode length of extensions bit-maps
+ * for SET and SEQUENCE types.
+ */
+int
+uper_put_nslength(asn_per_outp_t *po, size_t length) {
+ if(length <= 64) {
+ /* #11.9.3.4 */
+ if(length == 0) return -1;
+ return per_put_few_bits(po, length - 1, 7) ? -1 : 0;
+ } else {
+ int need_eom = 0;
+ if(uper_put_length(po, length, &need_eom) != (ssize_t)length
+ || need_eom) {
+ /* This might happen in case of >16K extensions */
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int
+per__imax_range(intmax_t lb, intmax_t ub, uintmax_t *range_r) {
+ uintmax_t bounds_range;
+ if((ub < 0) == (lb < 0)) {
+ bounds_range = ub - lb;
+ } else if(lb < 0) {
+ assert(ub >= 0);
+ bounds_range = 1 + ((uintmax_t)ub + (uintmax_t)-(lb + 1));
+ } else {
+ assert(!"Unreachable");
+ return -1;
+ }
+ *range_r = bounds_range;
+ return 0;
+}
+
+int
+per_imax_range_rebase(intmax_t v, intmax_t lb, intmax_t ub, uintmax_t *output) {
+ uintmax_t range;
+
+ assert(lb <= ub);
+
+ if(v < lb || v > ub || per__imax_range(lb, ub, &range) < 0) {
+ /* Range error. */
+ return -1;
+ }
+
+ /*
+ * Fundamentally what we're doing is returning (v-lb).
+ * However, this triggers undefined behavior when the word width
+ * of signed (v) is the same as the size of unsigned (*output).
+ * In practice, it triggers the UndefinedSanitizer. Therefore we shall
+ * compute the ranges accurately to avoid C's undefined behavior.
+ */
+ if((v < 0) == (lb < 0)) {
+ *output = v-lb;
+ return 0;
+ } else if(v < 0) {
+ uintmax_t rebased = 1 + (uintmax_t)-(v+1) + (uintmax_t)lb;
+ assert(rebased <= range); /* By construction */
+ *output = rebased;
+ return 0;
+ } else if(lb < 0) {
+ uintmax_t rebased = 1 + (uintmax_t)-(lb+1) + (uintmax_t)v;
+ assert(rebased <= range); /* By construction */
+ *output = rebased;
+ return 0;
+ } else {
+ assert(!"Unreachable");
+ return -1;
+ }
+}
+
+int
+per_long_range_rebase(long v, intmax_t lb, intmax_t ub, unsigned long *output) {
+ uintmax_t tmp = *output;
+ int rc = per_imax_range_rebase((intmax_t)v, lb, ub, &tmp);
+ *output = tmp;
+ return rc;
+}
+
+int
+per_imax_range_unrebase(uintmax_t inp, intmax_t lb, intmax_t ub, intmax_t *outp) {
+ uintmax_t range;
+
+ if(per__imax_range(lb, ub, &range) != 0) {
+ return -1;
+ }
+
+ if(inp > range) {
+ /*
+ * We can encode something in the given number of bits that technically
+ * exceeds the range. This is an avenue for security errors,
+ * so we don't allow that.
+ */
+ return -1;
+ }
+
+ if(inp <= INTMAX_MAX) {
+ *outp = (intmax_t)inp + lb;
+ } else {
+ *outp = (lb + INTMAX_MAX + 1) + (intmax_t)((inp - INTMAX_MAX) - 1);
+ }
+
+ return 0;
+}
+
+int
+per_long_range_unrebase(unsigned long inp, intmax_t lb, intmax_t ub, long *outp) {
+ intmax_t tmp = *outp;
+ int rc = per_imax_range_unrebase((uintmax_t)inp, lb, ub, &tmp);
+ *outp = tmp;
+ return rc;
+}
Code Review / sim / e2-interface.git / blobdiff