summaryrefslogtreecommitdiffstats
path: root/lib/isc/base32.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/isc/base32.c')
-rw-r--r--lib/isc/base32.c443
1 files changed, 443 insertions, 0 deletions
diff --git a/lib/isc/base32.c b/lib/isc/base32.c
new file mode 100644
index 0000000..90c37c7
--- /dev/null
+++ b/lib/isc/base32.c
@@ -0,0 +1,443 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <stdbool.h>
+
+#include <isc/base32.h>
+#include <isc/buffer.h>
+#include <isc/lex.h>
+#include <isc/region.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+#define RETERR(x) \
+ do { \
+ isc_result_t _r = (x); \
+ if (_r != ISC_R_SUCCESS) \
+ return ((_r)); \
+ } while (0)
+
+/*@{*/
+/*!
+ * These static functions are also present in lib/dns/rdata.c. I'm not
+ * sure where they should go. -- bwelling
+ */
+static isc_result_t
+str_totext(const char *source, isc_buffer_t *target);
+
+static isc_result_t
+mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length);
+
+/*@}*/
+
+static const char base32[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567="
+ "abcdefghijklmnopqrstuvwxyz234567";
+static const char base32hex[] = "0123456789ABCDEFGHIJKLMNOPQRSTUV="
+ "0123456789abcdefghijklmnopqrstuv";
+
+static isc_result_t
+base32_totext(isc_region_t *source, int wordlength, const char *wordbreak,
+ isc_buffer_t *target, const char base[], char pad) {
+ char buf[9];
+ unsigned int loops = 0;
+
+ if (wordlength >= 0 && wordlength < 8) {
+ wordlength = 8;
+ }
+
+ memset(buf, 0, sizeof(buf));
+ while (source->length > 0) {
+ buf[0] = base[((source->base[0] >> 3) & 0x1f)]; /* 5 + */
+ if (source->length == 1) {
+ buf[1] = base[(source->base[0] << 2) & 0x1c];
+ buf[2] = buf[3] = buf[4] = pad;
+ buf[5] = buf[6] = buf[7] = pad;
+ RETERR(str_totext(buf, target));
+ break;
+ }
+ buf[1] = base[((source->base[0] << 2) & 0x1c) | /* 3 = 8 */
+ ((source->base[1] >> 6) & 0x03)]; /* 2 + */
+ buf[2] = base[((source->base[1] >> 1) & 0x1f)]; /* 5 + */
+ if (source->length == 2) {
+ buf[3] = base[(source->base[1] << 4) & 0x10];
+ buf[4] = buf[5] = buf[6] = buf[7] = pad;
+ RETERR(str_totext(buf, target));
+ break;
+ }
+ buf[3] = base[((source->base[1] << 4) & 0x10) | /* 1 = 8 */
+ ((source->base[2] >> 4) & 0x0f)]; /* 4 + */
+ if (source->length == 3) {
+ buf[4] = base[(source->base[2] << 1) & 0x1e];
+ buf[5] = buf[6] = buf[7] = pad;
+ RETERR(str_totext(buf, target));
+ break;
+ }
+ buf[4] = base[((source->base[2] << 1) & 0x1e) | /* 4 = 8 */
+ ((source->base[3] >> 7) & 0x01)]; /* 1 + */
+ buf[5] = base[((source->base[3] >> 2) & 0x1f)]; /* 5 + */
+ if (source->length == 4) {
+ buf[6] = base[(source->base[3] << 3) & 0x18];
+ buf[7] = pad;
+ RETERR(str_totext(buf, target));
+ break;
+ }
+ buf[6] = base[((source->base[3] << 3) & 0x18) | /* 2 = 8 */
+ ((source->base[4] >> 5) & 0x07)]; /* 3 + */
+ buf[7] = base[source->base[4] & 0x1f]; /* 5 = 8 */
+ RETERR(str_totext(buf, target));
+ isc_region_consume(source, 5);
+
+ loops++;
+ if (source->length != 0 && wordlength >= 0 &&
+ (int)((loops + 1) * 8) >= wordlength)
+ {
+ loops = 0;
+ RETERR(str_totext(wordbreak, target));
+ }
+ }
+ if (source->length > 0) {
+ isc_region_consume(source, source->length);
+ }
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_base32_totext(isc_region_t *source, int wordlength, const char *wordbreak,
+ isc_buffer_t *target) {
+ return (base32_totext(source, wordlength, wordbreak, target, base32,
+ '='));
+}
+
+isc_result_t
+isc_base32hex_totext(isc_region_t *source, int wordlength,
+ const char *wordbreak, isc_buffer_t *target) {
+ return (base32_totext(source, wordlength, wordbreak, target, base32hex,
+ '='));
+}
+
+isc_result_t
+isc_base32hexnp_totext(isc_region_t *source, int wordlength,
+ const char *wordbreak, isc_buffer_t *target) {
+ return (base32_totext(source, wordlength, wordbreak, target, base32hex,
+ 0));
+}
+
+/*%
+ * State of a base32 decoding process in progress.
+ */
+typedef struct {
+ int length; /*%< Desired length of binary data or -1 */
+ isc_buffer_t *target; /*%< Buffer for resulting binary data */
+ int digits; /*%< Number of buffered base32 digits */
+ bool seen_end; /*%< True if "=" end marker seen */
+ int val[8];
+ const char *base; /*%< Which encoding we are using */
+ int seen_32; /*%< Number of significant bytes if non
+ * zero */
+ bool pad; /*%< Expect padding */
+} base32_decode_ctx_t;
+
+static void
+base32_decode_init(base32_decode_ctx_t *ctx, int length, const char base[],
+ bool pad, isc_buffer_t *target) {
+ ctx->digits = 0;
+ ctx->seen_end = false;
+ ctx->seen_32 = 0;
+ ctx->length = length;
+ ctx->target = target;
+ ctx->base = base;
+ ctx->pad = pad;
+}
+
+static isc_result_t
+base32_decode_char(base32_decode_ctx_t *ctx, int c) {
+ const char *s;
+ unsigned int last;
+
+ if (ctx->seen_end) {
+ return (ISC_R_BADBASE32);
+ }
+ if ((s = strchr(ctx->base, c)) == NULL) {
+ return (ISC_R_BADBASE32);
+ }
+ last = (unsigned int)(s - ctx->base);
+
+ /*
+ * Handle lower case.
+ */
+ if (last > 32) {
+ last -= 33;
+ }
+
+ /*
+ * Check that padding is contiguous.
+ */
+ if (last != 32 && ctx->seen_32 != 0) {
+ return (ISC_R_BADBASE32);
+ }
+
+ /*
+ * If padding is not permitted flag padding as a error.
+ */
+ if (last == 32 && !ctx->pad) {
+ return (ISC_R_BADBASE32);
+ }
+
+ /*
+ * Check that padding starts at the right place and that
+ * bits that should be zero are.
+ * Record how many significant bytes in answer (seen_32).
+ */
+ if (last == 32 && ctx->seen_32 == 0) {
+ switch (ctx->digits) {
+ case 0:
+ case 1:
+ return (ISC_R_BADBASE32);
+ case 2:
+ if ((ctx->val[1] & 0x03) != 0) {
+ return (ISC_R_BADBASE32);
+ }
+ ctx->seen_32 = 1;
+ break;
+ case 3:
+ return (ISC_R_BADBASE32);
+ case 4:
+ if ((ctx->val[3] & 0x0f) != 0) {
+ return (ISC_R_BADBASE32);
+ }
+ ctx->seen_32 = 2;
+ break;
+ case 5:
+ if ((ctx->val[4] & 0x01) != 0) {
+ return (ISC_R_BADBASE32);
+ }
+ ctx->seen_32 = 3;
+ break;
+ case 6:
+ return (ISC_R_BADBASE32);
+ case 7:
+ if ((ctx->val[6] & 0x07) != 0) {
+ return (ISC_R_BADBASE32);
+ }
+ ctx->seen_32 = 4;
+ break;
+ }
+ }
+
+ /*
+ * Zero fill pad values.
+ */
+ ctx->val[ctx->digits++] = (last == 32) ? 0 : last;
+
+ if (ctx->digits == 8) {
+ int n = 5;
+ unsigned char buf[5];
+
+ if (ctx->seen_32 != 0) {
+ ctx->seen_end = true;
+ n = ctx->seen_32;
+ }
+ buf[0] = (ctx->val[0] << 3) | (ctx->val[1] >> 2);
+ buf[1] = (ctx->val[1] << 6) | (ctx->val[2] << 1) |
+ (ctx->val[3] >> 4);
+ buf[2] = (ctx->val[3] << 4) | (ctx->val[4] >> 1);
+ buf[3] = (ctx->val[4] << 7) | (ctx->val[5] << 2) |
+ (ctx->val[6] >> 3);
+ buf[4] = (ctx->val[6] << 5) | (ctx->val[7]);
+ RETERR(mem_tobuffer(ctx->target, buf, n));
+ if (ctx->length >= 0) {
+ if (n > ctx->length) {
+ return (ISC_R_BADBASE32);
+ } else {
+ ctx->length -= n;
+ }
+ }
+ ctx->digits = 0;
+ }
+ return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+base32_decode_finish(base32_decode_ctx_t *ctx) {
+ if (ctx->length > 0) {
+ return (ISC_R_UNEXPECTEDEND);
+ }
+ /*
+ * Add missing padding if required.
+ */
+ if (!ctx->pad && ctx->digits != 0) {
+ ctx->pad = true;
+ do {
+ RETERR(base32_decode_char(ctx, '='));
+ } while (ctx->digits != 0);
+ }
+ if (ctx->digits != 0) {
+ return (ISC_R_BADBASE32);
+ }
+ return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+base32_tobuffer(isc_lex_t *lexer, const char base[], bool pad,
+ isc_buffer_t *target, int length) {
+ unsigned int before, after;
+ base32_decode_ctx_t ctx;
+ isc_textregion_t *tr;
+ isc_token_t token;
+ bool eol;
+
+ REQUIRE(length >= -2);
+
+ base32_decode_init(&ctx, length, base, pad, target);
+
+ before = isc_buffer_usedlength(target);
+ while (!ctx.seen_end && (ctx.length != 0)) {
+ unsigned int i;
+
+ if (length > 0) {
+ eol = false;
+ } else {
+ eol = true;
+ }
+ RETERR(isc_lex_getmastertoken(lexer, &token,
+ isc_tokentype_string, eol));
+ if (token.type != isc_tokentype_string) {
+ break;
+ }
+ tr = &token.value.as_textregion;
+ for (i = 0; i < tr->length; i++) {
+ RETERR(base32_decode_char(&ctx, tr->base[i]));
+ }
+ }
+ after = isc_buffer_usedlength(target);
+ if (ctx.length < 0 && !ctx.seen_end) {
+ isc_lex_ungettoken(lexer, &token);
+ }
+ RETERR(base32_decode_finish(&ctx));
+ if (length == -2 && before == after) {
+ return (ISC_R_UNEXPECTEDEND);
+ }
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_base32_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
+ return (base32_tobuffer(lexer, base32, true, target, length));
+}
+
+isc_result_t
+isc_base32hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
+ return (base32_tobuffer(lexer, base32hex, true, target, length));
+}
+
+isc_result_t
+isc_base32hexnp_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) {
+ return (base32_tobuffer(lexer, base32hex, false, target, length));
+}
+
+static isc_result_t
+base32_decodestring(const char *cstr, const char base[], bool pad,
+ isc_buffer_t *target) {
+ base32_decode_ctx_t ctx;
+
+ base32_decode_init(&ctx, -1, base, pad, target);
+ for (;;) {
+ int c = *cstr++;
+ if (c == '\0') {
+ break;
+ }
+ if (c == ' ' || c == '\t' || c == '\n' || c == '\r') {
+ continue;
+ }
+ RETERR(base32_decode_char(&ctx, c));
+ }
+ RETERR(base32_decode_finish(&ctx));
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_base32_decodestring(const char *cstr, isc_buffer_t *target) {
+ return (base32_decodestring(cstr, base32, true, target));
+}
+
+isc_result_t
+isc_base32hex_decodestring(const char *cstr, isc_buffer_t *target) {
+ return (base32_decodestring(cstr, base32hex, true, target));
+}
+
+isc_result_t
+isc_base32hexnp_decodestring(const char *cstr, isc_buffer_t *target) {
+ return (base32_decodestring(cstr, base32hex, false, target));
+}
+
+static isc_result_t
+base32_decoderegion(isc_region_t *source, const char base[], bool pad,
+ isc_buffer_t *target) {
+ base32_decode_ctx_t ctx;
+
+ base32_decode_init(&ctx, -1, base, pad, target);
+ while (source->length != 0) {
+ int c = *source->base;
+ RETERR(base32_decode_char(&ctx, c));
+ isc_region_consume(source, 1);
+ }
+ RETERR(base32_decode_finish(&ctx));
+ return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_base32_decoderegion(isc_region_t *source, isc_buffer_t *target) {
+ return (base32_decoderegion(source, base32, true, target));
+}
+
+isc_result_t
+isc_base32hex_decoderegion(isc_region_t *source, isc_buffer_t *target) {
+ return (base32_decoderegion(source, base32hex, true, target));
+}
+
+isc_result_t
+isc_base32hexnp_decoderegion(isc_region_t *source, isc_buffer_t *target) {
+ return (base32_decoderegion(source, base32hex, false, target));
+}
+
+static isc_result_t
+str_totext(const char *source, isc_buffer_t *target) {
+ unsigned int l;
+ isc_region_t region;
+
+ isc_buffer_availableregion(target, &region);
+ l = strlen(source);
+
+ if (l > region.length) {
+ return (ISC_R_NOSPACE);
+ }
+
+ memmove(region.base, source, l);
+ isc_buffer_add(target, l);
+ return (ISC_R_SUCCESS);
+}
+
+static isc_result_t
+mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) {
+ isc_region_t tr;
+
+ isc_buffer_availableregion(target, &tr);
+ if (length > tr.length) {
+ return (ISC_R_NOSPACE);
+ }
+ memmove(tr.base, base, length);
+ isc_buffer_add(target, length);
+ return (ISC_R_SUCCESS);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-03 22:32:37 +0000