base64.cpp@ 74762

Last change on this file since 74762 was 73704, checked in by vboxsync, 6 years ago
IPRT/base64.cpp: nit
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1	/* $Id: base64.cpp 73704 2018-08-16 09:29:48Z vboxsync $ */
2	/** @file
3	* IPRT - Base64, MIME content transfer encoding.
4	*/
5
6	/*
7	* Copyright (C) 2009-2017 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*********************************************************************************************************************************
29	* Header Files *
30	*********************************************************************************************************************************/
31	#include <iprt/base64.h>
32	#include "internal/iprt.h"
33
34	#include <iprt/assert.h>
35	#include <iprt/err.h>
36	#include <iprt/ctype.h>
37	#include <iprt/string.h>
38	#ifdef RT_STRICT
39	# include <iprt/asm.h>
40	#endif
41
42
43	/*********************************************************************************************************************************
44	* Defined Constants And Macros *
45	*********************************************************************************************************************************/
46	/** The line length used for encoding. */
47	#define RTBASE64_LINE_LEN 64
48
49	/** @name Special g_au8CharToVal values
50	* @{ */
51	#define BASE64_SPACE 0xc0
52	#define BASE64_PAD 0xe0
53	#define BASE64_INVALID 0xff
54	/** @} */
55
56
57	/*********************************************************************************************************************************
58	* Global Variables *
59	*********************************************************************************************************************************/
60	/** Base64 character to value. (RFC 2045)
61	* ASSUMES ASCII / UTF-8. */
62	static const uint8_t g_au8CharToVal[256] =
63	{
64	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc0, 0xc0, 0xc0, 0xc0, 0xc0, 0xff, 0xff, /* 0x00..0x0f */
65	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x10..0x1f */
66	0xc0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 62, 0xff, 0xff, 0xff, 63, /* 0x20..0x2f */
67	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0xff, 0xff, 0xff, 0xe0, 0xff, 0xff, /* 0x30..0x3f */
68	0xff, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 0x40..0x4f */
69	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x50..0x5f */
70	0xff, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 0x60..0x6f */
71	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x70..0x7f */
72	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x80..0x8f */
73	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x90..0x9f */
74	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xa0..0xaf */
75	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xb0..0xbf */
76	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xc0..0xcf */
77	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xd0..0xdf */
78	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0xe0..0xef */
79	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff /* 0xf0..0xff */
80	};
81
82	/** Value to Base64 character. (RFC 2045) */
83	static const char g_szValToChar[64+1] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
84
85
86	#ifdef RT_STRICT
87	/**
88	* Perform table sanity checks on the first call.
89	*/
90	static void rtBase64Sanity(void)
91	{
92	static bool s_fSane = false;
93	if (RT_UNLIKELY(!s_fSane))
94	{
95	for (unsigned i = 0; i < 64; i++)
96	{
97	unsigned ch = g_szValToChar[i];
98	Assert(ch);
99	Assert(g_au8CharToVal[ch] == i);
100	}
101
102	for (unsigned i = 0; i < 256; i++)
103	{
104	uint8_t u8 = g_au8CharToVal[i];
105	Assert( ( u8 == BASE64_INVALID
106	&& !RT_C_IS_ALNUM(i)
107	&& !RT_C_IS_SPACE(i))
108	\|\| ( u8 == BASE64_PAD
109	&& i == '=')
110	\|\| ( u8 == BASE64_SPACE
111	&& RT_C_IS_SPACE(i))
112	\|\| ( u8 < 64
113	&& (unsigned)g_szValToChar[u8] == i));
114	}
115	ASMAtomicWriteBool(&s_fSane, true);
116	}
117	}
118	#endif /* RT_STRICT */
119
120
121	RTDECL(ssize_t) RTBase64DecodedSizeEx(const char pszString, size_t cchStringMax, char *ppszEnd)
122	{
123	#ifdef RT_STRICT
124	rtBase64Sanity();
125	#endif
126
127	/*
128	* Walk the string until a non-encoded or non-space character is encountered.
129	*/
130	uint32_t c6Bits = 0;
131	uint8_t u8 = BASE64_INVALID;
132	unsigned ch = 0;
133	AssertCompile(sizeof(char) == sizeof(uint8_t));
134
135	while (cchStringMax > 0 && (ch = *pszString))
136	{
137	u8 = g_au8CharToVal[ch];
138	if (u8 < 64)
139	c6Bits++;
140	else if (RT_UNLIKELY(u8 != BASE64_SPACE))
141	break;
142
143	/* advance */
144	pszString++;
145	cchStringMax--;
146	}
147
148	/*
149	* Padding can only be found at the end and there is
150	* only 1 or 2 padding chars. Deal with it first.
151	*/
152	unsigned cbPad = 0;
153	if (u8 == BASE64_PAD)
154	{
155	cbPad = 1;
156	c6Bits++;
157	pszString++;
158	cchStringMax--;
159	while (cchStringMax > 0 && (ch = *pszString))
160	{
161	u8 = g_au8CharToVal[ch];
162	if (u8 != BASE64_SPACE)
163	{
164	if (u8 != BASE64_PAD)
165	break;
166	c6Bits++;
167	cbPad++;
168	}
169	pszString++;
170	cchStringMax--;
171	}
172	if (cbPad >= 3)
173	return -1;
174	}
175
176	/*
177	* Invalid char and no where to indicate where the
178	* Base64 text ends? Return failure.
179	*/
180	if ( u8 == BASE64_INVALID
181	&& !ppszEnd
182	&& ch)
183	return -1;
184
185	/*
186	* Recalc 6-bit to 8-bit and adjust for padding.
187	*/
188	size_t cb;
189	if (c6Bits * 3 / 3 == c6Bits)
190	{
191	if ((c6Bits * 3 % 4) != 0)
192	return -1;
193	cb = c6Bits * 3 / 4;
194	}
195	else
196	{
197	if ((c6Bits * (uint64_t)3 % 4) != 0)
198	return -1;
199	cb = c6Bits * (uint64_t)3 / 4;
200	}
201
202	if (cb < cbPad)
203	return -1;
204	cb -= cbPad;
205
206	if (ppszEnd)
207	ppszEnd = (char )pszString;
208	return cb;
209	}
210	RT_EXPORT_SYMBOL(RTBase64DecodedSizeEx);
211
212
213	RTDECL(ssize_t) RTBase64DecodedSize(const char pszString, char *ppszEnd)
214	{
215	return RTBase64DecodedSizeEx(pszString, RTSTR_MAX, ppszEnd);
216	}
217	RT_EXPORT_SYMBOL(RTBase64DecodedSize);
218
219
220	RTDECL(int) RTBase64DecodeEx(const char pszString, size_t cchStringMax, void pvData, size_t cbData,
221	size_t pcbActual, char *ppszEnd)
222	{
223	#ifdef RT_STRICT
224	rtBase64Sanity();
225	#endif
226
227	/*
228	* Process input in groups of 4 input / 3 output chars.
229	*/
230	uint8_t u8Trio[3] = { 0, 0, 0 }; /* shuts up gcc */
231	uint8_t pbData = (uint8_t )pvData;
232	unsigned ch;
233	uint8_t u8;
234	unsigned c6Bits = 0;
235	AssertCompile(sizeof(char) == sizeof(uint8_t));
236
237	for (;;)
238	{
239	/* The first 6-bit group. */
240	while ((u8 = g_au8CharToVal[ch = cchStringMax > 0 ? (uint8_t)*pszString : 0]) == BASE64_SPACE)
241	pszString++, cchStringMax--;
242	if (u8 >= 64)
243	{
244	c6Bits = 0;
245	break;
246	}
247	u8Trio[0] = u8 << 2;
248	pszString++;
249	cchStringMax--;
250
251	/* The second 6-bit group. */
252	while ((u8 = g_au8CharToVal[ch = cchStringMax > 0 ? (uint8_t)*pszString : 0]) == BASE64_SPACE)
253	pszString++, cchStringMax--;
254	if (u8 >= 64)
255	{
256	c6Bits = 1;
257	break;
258	}
259	u8Trio[0] \|= u8 >> 4;
260	u8Trio[1] = u8 << 4;
261	pszString++;
262	cchStringMax--;
263
264	/* The third 6-bit group. */
265	u8 = BASE64_INVALID;
266	while ((u8 = g_au8CharToVal[ch = cchStringMax > 0 ? (uint8_t)*pszString : 0]) == BASE64_SPACE)
267	pszString++, cchStringMax--;
268	if (u8 >= 64)
269	{
270	c6Bits = 2;
271	break;
272	}
273	u8Trio[1] \|= u8 >> 2;
274	u8Trio[2] = u8 << 6;
275	pszString++;
276	cchStringMax--;
277
278	/* The fourth 6-bit group. */
279	u8 = BASE64_INVALID;
280	while ((u8 = g_au8CharToVal[ch = cchStringMax > 0 ? (uint8_t)*pszString : 0]) == BASE64_SPACE)
281	pszString++, cchStringMax--;
282	if (u8 >= 64)
283	{
284	c6Bits = 3;
285	break;
286	}
287	u8Trio[2] \|= u8;
288	pszString++;
289	cchStringMax--;
290
291	/* flush the trio */
292	if (cbData < 3)
293	return VERR_BUFFER_OVERFLOW;
294	cbData -= 3;
295	pbData[0] = u8Trio[0];
296	pbData[1] = u8Trio[1];
297	pbData[2] = u8Trio[2];
298	pbData += 3;
299	}
300
301	/*
302	* Padding can only be found at the end and there is
303	* only 1 or 2 padding chars. Deal with it first.
304	*/
305	unsigned cbPad = 0;
306	if (u8 == BASE64_PAD)
307	{
308	cbPad = 1;
309	pszString++;
310	cchStringMax--;
311	while (cchStringMax > 0 && (ch = (uint8_t)*pszString))
312	{
313	u8 = g_au8CharToVal[ch];
314	if (u8 != BASE64_SPACE)
315	{
316	if (u8 != BASE64_PAD)
317	break;
318	cbPad++;
319	}
320	pszString++;
321	cchStringMax--;
322	}
323	if (cbPad >= 3)
324	return VERR_INVALID_BASE64_ENCODING;
325	}
326
327	/*
328	* Invalid char and no where to indicate where the
329	* Base64 text ends? Return failure.
330	*/
331	if ( u8 == BASE64_INVALID
332	&& !ppszEnd
333	&& ch != '\0')
334	return VERR_INVALID_BASE64_ENCODING;
335
336	/*
337	* Check padding vs. pending sextets, if anything left to do finish it off.
338	*/
339	if (c6Bits \|\| cbPad)
340	{
341	if (c6Bits + cbPad != 4)
342	return VERR_INVALID_BASE64_ENCODING;
343
344	switch (c6Bits)
345	{
346	case 1:
347	u8Trio[1] = u8Trio[2] = 0;
348	break;
349	case 2:
350	u8Trio[2] = 0;
351	break;
352	case 3:
353	default:
354	break;
355	}
356	switch (3 - cbPad)
357	{
358	case 1:
359	if (cbData < 1)
360	return VERR_BUFFER_OVERFLOW;
361	cbData--;
362	pbData[0] = u8Trio[0];
363	pbData++;
364	break;
365
366	case 2:
367	if (cbData < 2)
368	return VERR_BUFFER_OVERFLOW;
369	cbData -= 2;
370	pbData[0] = u8Trio[0];
371	pbData[1] = u8Trio[1];
372	pbData += 2;
373	break;
374
375	default:
376	break;
377	}
378	}
379
380	/*
381	* Set optional return values and return successfully.
382	*/
383	if (ppszEnd)
384	ppszEnd = (char )pszString;
385	if (pcbActual)
386	pcbActual = pbData - (uint8_t )pvData;
387	return VINF_SUCCESS;
388	}
389	RT_EXPORT_SYMBOL(RTBase64DecodeEx);
390
391
392	RTDECL(int) RTBase64Decode(const char pszString, void pvData, size_t cbData, size_t pcbActual, char *ppszEnd)
393	{
394	return RTBase64DecodeEx(pszString, RTSTR_MAX, pvData, cbData, pcbActual, ppszEnd);
395	}
396	RT_EXPORT_SYMBOL(RTBase64Decode);
397
398
399	/**
400	* Calculates the length of the Base64 encoding of a given number of bytes of
401	* data produced by RTBase64Encode().
402	*
403	* @returns The Base64 string length.
404	* @param cbData The number of bytes to encode.
405	*/
406	RTDECL(size_t) RTBase64EncodedLength(size_t cbData)
407	{
408	return RTBase64EncodedLengthEx(cbData, 0);
409	}
410	RT_EXPORT_SYMBOL(RTBase64EncodedLength);
411
412
413	/**
414	* Calculates the length of the Base64 encoding of a given number of bytes of
415	* data produced by RTBase64EncodeEx() with the same @a fFlags.
416	*
417	* @returns The Base64 string length.
418	* @param cbData The number of bytes to encode.
419	* @param fFlags Flags, any combination of the RTBASE64_FLAGS \#defines.
420	*/
421	RTDECL(size_t) RTBase64EncodedLengthEx(size_t cbData, uint32_t fFlags)
422	{
423	if (cbData * 8 / 8 != cbData)
424	{
425	AssertReturn(sizeof(size_t) == sizeof(uint64_t), ~(size_t)0);
426	uint64_t cch = cbData * (uint64_t)8;
427	while (cch % 24)
428	cch += 8;
429	cch /= 6;
430
431	if ((fFlags & RTBASE64_FLAGS_NO_LINE_BREAKS) == 0) /* add EOLs? */
432	cch += ((cch - 1) / RTBASE64_LINE_LEN) * RTBASE64_EOL_SIZE;
433	return cch;
434	}
435
436	size_t cch = cbData * 8;
437	while (cch % 24)
438	cch += 8;
439	cch /= 6;
440
441	if ((fFlags & RTBASE64_FLAGS_NO_LINE_BREAKS) == 0) /* add EOLs? */
442	cch += ((cch - 1) / RTBASE64_LINE_LEN) * RTBASE64_EOL_SIZE;
443	return cch;
444	}
445	RT_EXPORT_SYMBOL(RTBase64EncodedLengthEx);
446
447
448	/**
449	* Encodes the specifed data into a Base64 string, the caller supplies the
450	* output buffer.
451	*
452	* This is equivalent to calling RTBase64EncodeEx() with no flags.
453	*
454	* @returns IRPT status code.
455	* @retval VERR_BUFFER_OVERFLOW if the output buffer is too small. The buffer
456	* may contain an invalid Base64 string.
457	*
458	* @param pvData The data to encode.
459	* @param cbData The number of bytes to encode.
460	* @param pszBuf Where to put the Base64 string.
461	* @param cbBuf The size of the output buffer, including the terminator.
462	* @param pcchActual The actual number of characters returned.
463	*/
464	RTDECL(int) RTBase64Encode(const void pvData, size_t cbData, char pszBuf, size_t cbBuf, size_t *pcchActual)
465	{
466	return RTBase64EncodeEx(pvData, cbData, 0, pszBuf, cbBuf, pcchActual);
467	}
468	RT_EXPORT_SYMBOL(RTBase64Encode);
469
470
471	/**
472	* Encodes the specifed data into a Base64 string, the caller supplies the
473	* output buffer.
474	*
475	* @returns IRPT status code.
476	* @retval VERR_BUFFER_OVERFLOW if the output buffer is too small. The buffer
477	* may contain an invalid Base64 string.
478	*
479	* @param pvData The data to encode.
480	* @param cbData The number of bytes to encode.
481	* @param pszBuf Where to put the Base64 string.
482	* @param cbBuf The size of the output buffer, including the terminator.
483	* @param pcchActual The actual number of characters returned.
484	*/
485	RTDECL(int) RTBase64EncodeEx(const void *pvData, size_t cbData, uint32_t fFlags,
486	char pszBuf, size_t cbBuf, size_t pcchActual)
487	{
488	/*
489	* Process whole "trios" of input data.
490	*/
491	uint8_t u8A;
492	uint8_t u8B;
493	uint8_t u8C;
494	size_t cbLineFeed = cbBuf - RTBASE64_LINE_LEN;
495	const uint8_t pbSrc = (const uint8_t )pvData;
496	char *pchDst = pszBuf;
497	while (cbData >= 3)
498	{
499	if (cbBuf < 4 + 1)
500	return VERR_BUFFER_OVERFLOW;
501
502	/* encode */
503	u8A = pbSrc[0];
504	pchDst[0] = g_szValToChar[u8A >> 2];
505	u8B = pbSrc[1];
506	pchDst[1] = g_szValToChar[((u8A << 4) & 0x3f) \| (u8B >> 4)];
507	u8C = pbSrc[2];
508	pchDst[2] = g_szValToChar[((u8B << 2) & 0x3f) \| (u8C >> 6)];
509	pchDst[3] = g_szValToChar[u8C & 0x3f];
510
511	/* advance */
512	cbBuf -= 4;
513	pchDst += 4;
514	cbData -= 3;
515	pbSrc += 3;
516
517	if ((fFlags & RTBASE64_FLAGS_NO_LINE_BREAKS) == 0) /* add EOLs? */
518	{
519	/* deal out end-of-line */
520	if (cbBuf == cbLineFeed && cbData)
521	{
522	if (cbBuf < RTBASE64_EOL_SIZE + 1)
523	return VERR_BUFFER_OVERFLOW;
524	cbBuf -= RTBASE64_EOL_SIZE;
525	if (RTBASE64_EOL_SIZE == 2)
526	*pchDst++ = '\r';
527	*pchDst++ = '\n';
528	cbLineFeed = cbBuf - RTBASE64_LINE_LEN;
529	}
530	}
531	}
532
533	/*
534	* Deal with the odd bytes and string termination.
535	*/
536	if (cbData)
537	{
538	if (cbBuf < 4 + 1)
539	return VERR_BUFFER_OVERFLOW;
540	switch (cbData)
541	{
542	case 1:
543	u8A = pbSrc[0];
544	pchDst[0] = g_szValToChar[u8A >> 2];
545	pchDst[1] = g_szValToChar[(u8A << 4) & 0x3f];
546	pchDst[2] = '=';
547	pchDst[3] = '=';
548	break;
549	case 2:
550	u8A = pbSrc[0];
551	pchDst[0] = g_szValToChar[u8A >> 2];
552	u8B = pbSrc[1];
553	pchDst[1] = g_szValToChar[((u8A << 4) & 0x3f) \| (u8B >> 4)];
554	pchDst[2] = g_szValToChar[(u8B << 2) & 0x3f];
555	pchDst[3] = '=';
556	break;
557	}
558	pchDst += 4;
559	}
560
561	*pchDst = '\0';
562
563	if (pcchActual)
564	*pcchActual = pchDst - pszBuf;
565	return VINF_SUCCESS;
566	}
567	RT_EXPORT_SYMBOL(RTBase64EncodeEx);

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source: vbox/trunk/src/VBox/Runtime/common/string/base64.cpp@ 74762

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