/* * Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1998-2001, 2003 Internet Software Consortium. * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ /* $Id: base64.c,v 1.23.2.3 2004/03/09 06:11:45 marka Exp $ */ #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[] = "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)); } 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)); } 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 */ isc_boolean_t 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 = ISC_FALSE; ctx->length = length; ctx->target = target; } static inline isc_result_t base64_decode_char(base64_decode_ctx_t *ctx, int c) { char *s; if (ctx->seen_end) return (ISC_R_BADBASE64); if ((s = strchr(base64, c)) == NULL) return (ISC_R_BADBASE64); ctx->val[ctx->digits++] = 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 = ISC_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; isc_boolean_t eol; base64_decode_init(&ctx, length, target); while (!ctx.seen_end && (ctx.length != 0)) { unsigned int i; if (length > 0) eol = ISC_FALSE; else eol = ISC_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); memcpy(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); memcpy(tr.base, base, length); isc_buffer_add(target, length); return (ISC_R_SUCCESS); }