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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 18:37:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 18:37:14 +0000 |
commit | ea648e70a989cca190cd7403fe892fd2dcc290b4 (patch) | |
tree | e2b6b1c647da68b0d4d66082835e256eb30970e8 /lib/isc/base64.c | |
parent | Initial commit. (diff) | |
download | bind9-ea648e70a989cca190cd7403fe892fd2dcc290b4.tar.xz bind9-ea648e70a989cca190cd7403fe892fd2dcc290b4.zip |
Adding upstream version 1:9.11.5.P4+dfsg.upstream/1%9.11.5.P4+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/isc/base64.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/lib/isc/base64.c b/lib/isc/base64.c new file mode 100644 index 0000000..c7a1722 --- /dev/null +++ b/lib/isc/base64.c @@ -0,0 +1,247 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * 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 http://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + + +/*! \file */ + +#include <config.h> + +#include <stdbool.h> + +#include <isc/base64.h> +#include <isc/buffer.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) + + +/*@{*/ +/*! + * 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[] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; +/*@}*/ + +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 inline 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 inline 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 inline 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) { + base64_decode_ctx_t ctx; + isc_textregion_t *tr; + isc_token_t token; + bool eol; + + base64_decode_init(&ctx, length, 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])); + } + if (ctx.length < 0 && !ctx.seen_end) + isc_lex_ungettoken(lexer, &token); + RETERR(base64_decode_finish(&ctx)); + 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); +} |