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Diffstat (limited to '')
| -rw-r--r-- | lib/isc/hex.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/lib/isc/hex.c b/lib/isc/hex.c new file mode 100644 index 0000000..be67f03 --- /dev/null +++ b/lib/isc/hex.c @@ -0,0 +1,212 @@ +/* + * 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 <ctype.h> +#include <stdbool.h> + +#include <isc/buffer.h> +#include <isc/hex.h> +#include <isc/lex.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) + +/* + * BEW: These static functions are copied from lib/dns/rdata.c. + */ +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 hex[] = "0123456789ABCDEF"; + +isc_result_t +isc_hex_totext(isc_region_t *source, int wordlength, const char *wordbreak, + isc_buffer_t *target) { + char buf[3]; + unsigned int loops = 0; + + if (wordlength < 2) { + wordlength = 2; + } + + memset(buf, 0, sizeof(buf)); + while (source->length > 0) { + buf[0] = hex[(source->base[0] >> 4) & 0xf]; + buf[1] = hex[(source->base[0]) & 0xf]; + RETERR(str_totext(buf, target)); + isc_region_consume(source, 1); + + loops++; + if (source->length != 0 && (int)((loops + 1) * 2) >= wordlength) + { + loops = 0; + RETERR(str_totext(wordbreak, target)); + } + } + return (ISC_R_SUCCESS); +} + +/*% + * State of a hex 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 hex digits */ + int val[2]; +} hex_decode_ctx_t; + +static void +hex_decode_init(hex_decode_ctx_t *ctx, int length, isc_buffer_t *target) { + ctx->digits = 0; + ctx->length = length; + ctx->target = target; +} + +static isc_result_t +hex_decode_char(hex_decode_ctx_t *ctx, int c) { + const char *s; + + if ((s = strchr(hex, toupper(c))) == NULL) { + return (ISC_R_BADHEX); + } + ctx->val[ctx->digits++] = (int)(s - hex); + if (ctx->digits == 2) { + unsigned char num; + + num = (ctx->val[0] << 4) + (ctx->val[1]); + RETERR(mem_tobuffer(ctx->target, &num, 1)); + if (ctx->length >= 0) { + if (ctx->length == 0) { + return (ISC_R_BADHEX); + } else { + ctx->length -= 1; + } + } + ctx->digits = 0; + } + return (ISC_R_SUCCESS); +} + +static isc_result_t +hex_decode_finish(hex_decode_ctx_t *ctx) { + if (ctx->length > 0) { + return (ISC_R_UNEXPECTEDEND); + } + if (ctx->digits != 0) { + return (ISC_R_BADHEX); + } + return (ISC_R_SUCCESS); +} + +isc_result_t +isc_hex_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) { + unsigned int before, after; + hex_decode_ctx_t ctx; + isc_textregion_t *tr; + isc_token_t token; + bool eol; + + REQUIRE(length >= -2); + + hex_decode_init(&ctx, length, target); + + before = isc_buffer_usedlength(target); + while (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(hex_decode_char(&ctx, tr->base[i])); + } + } + after = isc_buffer_usedlength(target); + if (ctx.length < 0) { + isc_lex_ungettoken(lexer, &token); + } + RETERR(hex_decode_finish(&ctx)); + if (length == -2 && before == after) { + return (ISC_R_UNEXPECTEDEND); + } + return (ISC_R_SUCCESS); +} + +isc_result_t +isc_hex_decodestring(const char *cstr, isc_buffer_t *target) { + hex_decode_ctx_t ctx; + + hex_decode_init(&ctx, -1, target); + for (;;) { + int c = *cstr++; + if (c == '\0') { + break; + } + if (c == ' ' || c == '\t' || c == '\n' || c == '\r') { + continue; + } + RETERR(hex_decode_char(&ctx, c)); + } + RETERR(hex_decode_finish(&ctx)); + return (ISC_R_SUCCESS); +} + +static isc_result_t +str_totext(const char *source, isc_buffer_t *target) { + unsigned int l; + isc_region_t region; + + isc_buffer_availableregion(target, ®ion); + 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); +} |