From 45d6379135504814ab723b57f0eb8be23393a51d Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 09:24:22 +0200 Subject: Adding upstream version 1:9.16.44. Signed-off-by: Daniel Baumann --- lib/isc/base64.c | 270 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 270 insertions(+) create mode 100644 lib/isc/base64.c (limited to 'lib/isc/base64.c') diff --git a/lib/isc/base64.c b/lib/isc/base64.c new file mode 100644 index 0000000..958ef4f --- /dev/null +++ b/lib/isc/base64.c @@ -0,0 +1,270 @@ +/* + * 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 + +#include +#include +#include +#include +#include + +#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 base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvw" + "xyz0123456789+/="; +/*@}*/ + +isc_result_t +isc_base64_totext(isc_region_t *source, int wordlength, const char *wordbreak, + isc_buffer_t *target) { + char buf[5]; + unsigned int loops = 0; + + if (wordlength < 4) { + wordlength = 4; + } + + memset(buf, 0, sizeof(buf)); + while (source->length > 2) { + buf[0] = base64[(source->base[0] >> 2) & 0x3f]; + buf[1] = base64[((source->base[0] << 4) & 0x30) | + ((source->base[1] >> 4) & 0x0f)]; + buf[2] = base64[((source->base[1] << 2) & 0x3c) | + ((source->base[2] >> 6) & 0x03)]; + buf[3] = base64[source->base[2] & 0x3f]; + RETERR(str_totext(buf, target)); + isc_region_consume(source, 3); + + loops++; + if (source->length != 0 && (int)((loops + 1) * 4) >= wordlength) + { + loops = 0; + RETERR(str_totext(wordbreak, target)); + } + } + if (source->length == 2) { + buf[0] = base64[(source->base[0] >> 2) & 0x3f]; + buf[1] = base64[((source->base[0] << 4) & 0x30) | + ((source->base[1] >> 4) & 0x0f)]; + buf[2] = base64[((source->base[1] << 2) & 0x3c)]; + buf[3] = '='; + RETERR(str_totext(buf, target)); + isc_region_consume(source, 2); + } else if (source->length == 1) { + buf[0] = base64[(source->base[0] >> 2) & 0x3f]; + buf[1] = base64[((source->base[0] << 4) & 0x30)]; + buf[2] = buf[3] = '='; + RETERR(str_totext(buf, target)); + isc_region_consume(source, 1); + } + return (ISC_R_SUCCESS); +} + +/*% + * State of a base64 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 base64 digits */ + bool seen_end; /*%< True if "=" end marker seen */ + int val[4]; +} base64_decode_ctx_t; + +static void +base64_decode_init(base64_decode_ctx_t *ctx, int length, isc_buffer_t *target) { + ctx->digits = 0; + ctx->seen_end = false; + ctx->length = length; + ctx->target = target; +} + +static isc_result_t +base64_decode_char(base64_decode_ctx_t *ctx, int c) { + const char *s; + + if (ctx->seen_end) { + return (ISC_R_BADBASE64); + } + if ((s = strchr(base64, c)) == NULL) { + return (ISC_R_BADBASE64); + } + ctx->val[ctx->digits++] = (int)(s - base64); + if (ctx->digits == 4) { + int n; + unsigned char buf[3]; + if (ctx->val[0] == 64 || ctx->val[1] == 64) { + return (ISC_R_BADBASE64); + } + if (ctx->val[2] == 64 && ctx->val[3] != 64) { + return (ISC_R_BADBASE64); + } + /* + * Check that bits that should be zero are. + */ + if (ctx->val[2] == 64 && (ctx->val[1] & 0xf) != 0) { + return (ISC_R_BADBASE64); + } + /* + * We don't need to test for ctx->val[2] != 64 as + * the bottom two bits of 64 are zero. + */ + if (ctx->val[3] == 64 && (ctx->val[2] & 0x3) != 0) { + return (ISC_R_BADBASE64); + } + n = (ctx->val[2] == 64) ? 1 : (ctx->val[3] == 64) ? 2 : 3; + if (n != 3) { + ctx->seen_end = true; + if (ctx->val[2] == 64) { + ctx->val[2] = 0; + } + if (ctx->val[3] == 64) { + ctx->val[3] = 0; + } + } + buf[0] = (ctx->val[0] << 2) | (ctx->val[1] >> 4); + buf[1] = (ctx->val[1] << 4) | (ctx->val[2] >> 2); + buf[2] = (ctx->val[2] << 6) | (ctx->val[3]); + RETERR(mem_tobuffer(ctx->target, buf, n)); + if (ctx->length >= 0) { + if (n > ctx->length) { + return (ISC_R_BADBASE64); + } else { + ctx->length -= n; + } + } + ctx->digits = 0; + } + return (ISC_R_SUCCESS); +} + +static isc_result_t +base64_decode_finish(base64_decode_ctx_t *ctx) { + if (ctx->length > 0) { + return (ISC_R_UNEXPECTEDEND); + } + if (ctx->digits != 0) { + return (ISC_R_BADBASE64); + } + return (ISC_R_SUCCESS); +} + +isc_result_t +isc_base64_tobuffer(isc_lex_t *lexer, isc_buffer_t *target, int length) { + unsigned int before, after; + base64_decode_ctx_t ctx; + isc_textregion_t *tr; + isc_token_t token; + bool eol; + + REQUIRE(length >= -2); + + base64_decode_init(&ctx, length, 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(base64_decode_char(&ctx, tr->base[i])); + } + } + after = isc_buffer_usedlength(target); + if (ctx.length < 0 && !ctx.seen_end) { + isc_lex_ungettoken(lexer, &token); + } + RETERR(base64_decode_finish(&ctx)); + if (length == -2 && before == after) { + return (ISC_R_UNEXPECTEDEND); + } + return (ISC_R_SUCCESS); +} + +isc_result_t +isc_base64_decodestring(const char *cstr, isc_buffer_t *target) { + base64_decode_ctx_t ctx; + + base64_decode_init(&ctx, -1, target); + for (;;) { + int c = *cstr++; + if (c == '\0') { + break; + } + if (c == ' ' || c == '\t' || c == '\n' || c == '\r') { + continue; + } + RETERR(base64_decode_char(&ctx, c)); + } + RETERR(base64_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); +} -- cgit v1.2.3