src/lib/support/Base64.cpp - third_party/openweave-core - Git at Google

 /*
  *
  *    Copyright (c) 2013-2017 Nest Labs, Inc.
  *    All rights reserved.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
  *    You may obtain a copy of the License at
  *
  *        http://www.apache.org/licenses/LICENSE-2.0
  *
  *    Unless required by applicable law or agreed to in writing, software
  *    distributed under the License is distributed on an "AS IS" BASIS,
  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  *    See the License for the specific language governing permissions and
  *    limitations under the License.
  */

 /**
  *    @file
  *      Base-64 utility functions.
  *
  */

 #ifndef __STDC_LIMIT_MACROS
 #define __STDC_LIMIT_MACROS
 #endif
 #include <ctype.h>
 #include <stdint.h>

 #include "Base64.h"

 namespace nl {

 // Convert a value in the range 0..63 to its equivalent base64 character.
 // Return '=' for any value >= 64.
 static char Base64ValToChar(uint8_t val)
 {
     if (val < 26)
         return 'A' + val;
     val -= 26;
     if (val < 26)
         return 'a' + val;
     val -= 26;
     if (val < 10)
         return '0' + val;
     if (val == 10)
         return '+';
     if (val == 11)
         return '/';
     return '=';
 }

 // Convert a base64 character to a value in the range 0..63, or UINT8_MAX if the character is invalid.
 static uint8_t Base64CharToVal(uint8_t c)
 {
     if (c == 43)
         return 62;
     if (c == 47)
         return 63;
     // NOTE: c < 48 will fall through to return UINT8_MAX below.
     c -= 48;
     if (c < 10)
         return c + 52;
     c -= 17;
     if (c < 26)
         return c;
     c -= 32;
     if (c < 26)
         return c + 26;
     return UINT8_MAX;
 }

 // Convert a value in the range 0..63 to its equivalent base64url character (see RFC-4648, section 5).
 // Return '=' for any value >= 64.
 static char Base64URLValToChar(uint8_t val)
 {
     if (val < 26)
         return 'A' + val;
     val -= 26;
     if (val < 26)
         return 'a' + val;
     val -= 26;
     if (val < 10)
         return '0' + val;
     if (val == 10)
         return '-';
     if (val == 11)
         return '_';
     return '=';
 }

 // Convert a base64url character to a value in the range 0..63, or UINT8_MAX if the character is invalid.
 static uint8_t Base64URLCharToVal(uint8_t c)
 {
     if (c == 45)
         return 62;
     if (c == 95)
         return 63;
     // NOTE: c < 48 will fall through to return UINT8_MAX below.
     c -= 48;
     if (c < 10)
         return c + 52;
     c -= 17;
     if (c < 26)
         return c;
     c -= 32;
     if (c < 26)
         return c + 26;
     return UINT8_MAX;
 }

 uint16_t Base64Encode(const uint8_t *in, uint16_t inLen, char *out, Base64ValToCharFunct valToCharFunct)
 {
     char *outStart = out;

     while (inLen > 0)
     {
         uint8_t val1, val2, val3, val4;

         val1 = *in >> 2;
         val2 = (*in << 4) & 0x3F;
         in++;
         inLen--;
         if (inLen > 0)
         {
             val2 |= *in >> 4;
             val3 =  (*in << 2) & 0x3F;
             in++;
             inLen--;
             if (inLen > 0)
             {
                 val3 |= *in >> 6;
                 val4  = *in & 0x3F;
                 in++;
                 inLen--;
             }
             else
                 val4 = UINT8_MAX;
         }
         else
             val3 = val4 = UINT8_MAX;

         *out++ = valToCharFunct(val1);
         *out++ = valToCharFunct(val2);
         *out++ = valToCharFunct(val3);
         *out++ = valToCharFunct(val4);
     }

     return out - outStart;
 }

 uint16_t Base64Encode(const uint8_t *in, uint16_t inLen, char *out)
 {
     return Base64Encode(in, inLen, out, Base64ValToChar);
 }

 uint16_t Base64URLEncode(const uint8_t *in, uint16_t inLen, char *out)
 {
     return Base64Encode(in, inLen, out, Base64URLValToChar);
 }

 uint32_t Base64Encode32(const uint8_t *in, uint32_t inLen, char *out, Base64ValToCharFunct valToCharFunct)
 {
     uint32_t outLen = 0;

     // Maximum number of input bytes to convert to base-64 in a single call to Base64Encode.
     // Number is the largest multiple of 3 bytes where the resulting number of base-64 characters
     // fits within a uint16_t.
     enum { kMaxConvert = (UINT16_MAX / 4) * 3 };

     while (true)
     {
         uint16_t inChunkLen = (inLen > kMaxConvert) ? (uint16_t)kMaxConvert : (uint16_t)inLen;

         uint16_t outChunkLen = Base64Encode(in, inChunkLen, out, valToCharFunct);

         inLen -= inChunkLen;
         outLen += outChunkLen;

         if (inLen == 0)
             break;

         in += inChunkLen;
         out += outChunkLen;
     }

     return outLen;
 }

 uint32_t Base64Encode32(const uint8_t *in, uint32_t inLen, char *out)
 {
     return Base64Encode32(in, inLen, out, Base64ValToChar);
 }

 uint16_t Base64Decode(const char *in, uint16_t inLen, uint8_t *out, Base64CharToValFunct charToValFunct)
 {
     uint8_t *outStart = out;

     // isgraph() returns false for space and ctrl chars
     while (inLen > 0 && isgraph(*in))
     {
         if (inLen == 1)
             goto fail;

         uint8_t a = charToValFunct(*in++);
         uint8_t b = charToValFunct(*in++);
         inLen -= 2;

         if (a == UINT8_MAX || b == UINT8_MAX)
             goto fail;

         *out++ = (a << 2) | (b >> 4);

         if (inLen == 0 || *in == '=')
             break;

         uint8_t c = charToValFunct(*in++);
         inLen--;

         if (c == UINT8_MAX)
             goto fail;

         *out++ = (b << 4) | (c >> 2);

         if (inLen == 0 || *in == '=')
             break;

         uint8_t d = charToValFunct(*in++);
         inLen--;

         if (d == UINT8_MAX)
             goto fail;

         *out++ = (c << 6) | d;
     }

     return out - outStart;

 fail:
     return UINT16_MAX;
 }

 uint16_t Base64Decode(const char *in, uint16_t inLen, uint8_t *out)
 {
     return Base64Decode(in, inLen, out, Base64CharToVal);
 }

 uint16_t Base64URLDecode(const char *in, uint16_t inLen, uint8_t *out)
 {
     return Base64Decode(in, inLen, out, Base64URLCharToVal);
 }

 uint32_t Base64Decode32(const char *in, uint32_t inLen, uint8_t *out, Base64CharToValFunct charToValFunct)
 {
     uint32_t outLen = 0;

     // Maximum number of base-64 characters to convert in a single call to Base64Decode.
     // Number is the largest multiple of 4 characters that fits in a uint16_t.
     enum { kMaxConvert = (UINT16_MAX / 4) * 4 };

     while (true)
     {
         uint16_t inChunkLen = (inLen > kMaxConvert) ? (uint16_t)kMaxConvert : (uint16_t)inLen;

         uint16_t outChunkLen = Base64Decode(in, inChunkLen, out, charToValFunct);
         if (outChunkLen == UINT16_MAX)
             return UINT32_MAX;

         inLen -= inChunkLen;
         outLen += outChunkLen;

         if (inLen == 0)
             break;

         in += inChunkLen;
         out += outChunkLen;
     }

     return outLen;
 }

 uint32_t Base64Decode32(const char *in, uint32_t inLen, uint8_t *out)
 {
     return Base64Decode32(in, inLen, out, Base64CharToVal);
 }


 } // namespace nl

 #ifdef TEST

 #include <string.h>
 #include <stdio.h>

 void TestBase64(const char *test, bool base64URL=false)
 {
     uint8_t buf[256];
     char buf2[256];
     uint16_t len;

     strcpy((char *)buf, test);

     len = (base64URL)
           ? nl::Base64URLDecode((char *)buf, strlen((char *)buf), buf)
           : nl::Base64Decode((char *)buf, strlen((char *)buf), buf);
     printf("%s: ", test);
     if (len != UINT16_MAX)
     {
         printf("(%d) ", len);
         for (uint16_t i = 0; i < len; i++)
             printf("%c", buf[i]);

         len = (base64URL)
               ? nl::Base64URLEncode(buf, len, buf2)
               : nl::Base64Encode(buf, len, buf2);
         printf(" (%d) ", len);
         for (uint16_t i = 0; i < len; i++)
             printf("%c", buf2[i]);
     }
     else
         printf("ERROR");
     printf("\n");
 }

 int main(int argc, char *argv[])
 {
     TestBase64("");
     TestBase64("Zg==");
     TestBase64("Zm8=");
     TestBase64("Zm9v");
     TestBase64("Zm9vYg==");
     TestBase64("Zm9vYmE=");
     TestBase64("Zm9vYmFy");
     TestBase64("QmFzZTY0D+8xMjM0D/8=");

     TestBase64("Zg");
     TestBase64("Zm8");
     TestBase64("Zm9vYg");
     TestBase64("Zm9vYmE");

     TestBase64("QmFzZTY0D-8xMjM0D_8=", true);

     // Error cases
     TestBase64("Z");
     TestBase64("Z\x019vYmFy");
     TestBase64("Zm9vY");
     TestBase64("Zm9vY;");
     TestBase64("Zm9 vYg");
 }

 #endif // TEST
	/*
	*
	* Copyright (c) 2013-2017 Nest Labs, Inc.
	* All rights reserved.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	/**
	* @file
	* Base-64 utility functions.
	*
	*/

	#ifndef __STDC_LIMIT_MACROS
	#define __STDC_LIMIT_MACROS
	#endif
	#include <ctype.h>
	#include <stdint.h>

	#include "Base64.h"

	namespace nl {

	// Convert a value in the range 0..63 to its equivalent base64 character.
	// Return '=' for any value >= 64.
	static char Base64ValToChar(uint8_t val)
	{
	if (val < 26)
	return 'A' + val;
	val -= 26;
	if (val < 26)
	return 'a' + val;
	val -= 26;
	if (val < 10)
	return '0' + val;
	if (val == 10)
	return '+';
	if (val == 11)
	return '/';
	return '=';
	}

	// Convert a base64 character to a value in the range 0..63, or UINT8_MAX if the character is invalid.
	static uint8_t Base64CharToVal(uint8_t c)
	{
	if (c == 43)
	return 62;
	if (c == 47)
	return 63;
	// NOTE: c < 48 will fall through to return UINT8_MAX below.
	c -= 48;
	if (c < 10)
	return c + 52;
	c -= 17;
	if (c < 26)
	return c;
	c -= 32;
	if (c < 26)
	return c + 26;
	return UINT8_MAX;
	}

	// Convert a value in the range 0..63 to its equivalent base64url character (see RFC-4648, section 5).
	// Return '=' for any value >= 64.
	static char Base64URLValToChar(uint8_t val)
	{
	if (val < 26)
	return 'A' + val;
	val -= 26;
	if (val < 26)
	return 'a' + val;
	val -= 26;
	if (val < 10)
	return '0' + val;
	if (val == 10)
	return '-';
	if (val == 11)
	return '_';
	return '=';
	}

	// Convert a base64url character to a value in the range 0..63, or UINT8_MAX if the character is invalid.
	static uint8_t Base64URLCharToVal(uint8_t c)
	{
	if (c == 45)
	return 62;
	if (c == 95)
	return 63;
	// NOTE: c < 48 will fall through to return UINT8_MAX below.
	c -= 48;
	if (c < 10)
	return c + 52;
	c -= 17;
	if (c < 26)
	return c;
	c -= 32;
	if (c < 26)
	return c + 26;
	return UINT8_MAX;
	}

	uint16_t Base64Encode(const uint8_t in, uint16_t inLen, char out, Base64ValToCharFunct valToCharFunct)
	{
	char *outStart = out;

	while (inLen > 0)
	{
	uint8_t val1, val2, val3, val4;

	val1 = *in >> 2;
	val2 = (*in << 4) & 0x3F;
	in++;
	inLen--;
	if (inLen > 0)
	{
	val2 \|= *in >> 4;
	val3 = (*in << 2) & 0x3F;
	in++;
	inLen--;
	if (inLen > 0)
	{
	val3 \|= *in >> 6;
	val4 = *in & 0x3F;
	in++;
	inLen--;
	}
	else
	val4 = UINT8_MAX;
	}
	else
	val3 = val4 = UINT8_MAX;

	*out++ = valToCharFunct(val1);
	*out++ = valToCharFunct(val2);
	*out++ = valToCharFunct(val3);
	*out++ = valToCharFunct(val4);
	}

	return out - outStart;
	}

	uint16_t Base64Encode(const uint8_t in, uint16_t inLen, char out)
	{
	return Base64Encode(in, inLen, out, Base64ValToChar);
	}

	uint16_t Base64URLEncode(const uint8_t in, uint16_t inLen, char out)
	{
	return Base64Encode(in, inLen, out, Base64URLValToChar);
	}

	uint32_t Base64Encode32(const uint8_t in, uint32_t inLen, char out, Base64ValToCharFunct valToCharFunct)
	{
	uint32_t outLen = 0;

	// Maximum number of input bytes to convert to base-64 in a single call to Base64Encode.
	// Number is the largest multiple of 3 bytes where the resulting number of base-64 characters
	// fits within a uint16_t.
	enum { kMaxConvert = (UINT16_MAX / 4) * 3 };

	while (true)
	{
	uint16_t inChunkLen = (inLen > kMaxConvert) ? (uint16_t)kMaxConvert : (uint16_t)inLen;

	uint16_t outChunkLen = Base64Encode(in, inChunkLen, out, valToCharFunct);

	inLen -= inChunkLen;
	outLen += outChunkLen;

	if (inLen == 0)
	break;

	in += inChunkLen;
	out += outChunkLen;
	}

	return outLen;
	}

	uint32_t Base64Encode32(const uint8_t in, uint32_t inLen, char out)
	{
	return Base64Encode32(in, inLen, out, Base64ValToChar);
	}

	uint16_t Base64Decode(const char in, uint16_t inLen, uint8_t out, Base64CharToValFunct charToValFunct)
	{
	uint8_t *outStart = out;

	// isgraph() returns false for space and ctrl chars
	while (inLen > 0 && isgraph(*in))
	{
	if (inLen == 1)
	goto fail;

	uint8_t a = charToValFunct(*in++);
	uint8_t b = charToValFunct(*in++);
	inLen -= 2;

	if (a == UINT8_MAX \|\| b == UINT8_MAX)
	goto fail;

	*out++ = (a << 2) \| (b >> 4);

	if (inLen == 0 \|\| *in == '=')
	break;

	uint8_t c = charToValFunct(*in++);
	inLen--;

	if (c == UINT8_MAX)
	goto fail;

	*out++ = (b << 4) \| (c >> 2);

	if (inLen == 0 \|\| *in == '=')
	break;

	uint8_t d = charToValFunct(*in++);
	inLen--;

	if (d == UINT8_MAX)
	goto fail;

	*out++ = (c << 6) \| d;
	}

	return out - outStart;

	fail:
	return UINT16_MAX;
	}

	uint16_t Base64Decode(const char in, uint16_t inLen, uint8_t out)
	{
	return Base64Decode(in, inLen, out, Base64CharToVal);
	}

	uint16_t Base64URLDecode(const char in, uint16_t inLen, uint8_t out)
	{
	return Base64Decode(in, inLen, out, Base64URLCharToVal);
	}

	uint32_t Base64Decode32(const char in, uint32_t inLen, uint8_t out, Base64CharToValFunct charToValFunct)
	{
	uint32_t outLen = 0;

	// Maximum number of base-64 characters to convert in a single call to Base64Decode.
	// Number is the largest multiple of 4 characters that fits in a uint16_t.
	enum { kMaxConvert = (UINT16_MAX / 4) * 4 };

	while (true)
	{
	uint16_t inChunkLen = (inLen > kMaxConvert) ? (uint16_t)kMaxConvert : (uint16_t)inLen;

	uint16_t outChunkLen = Base64Decode(in, inChunkLen, out, charToValFunct);
	if (outChunkLen == UINT16_MAX)
	return UINT32_MAX;

	inLen -= inChunkLen;
	outLen += outChunkLen;

	if (inLen == 0)
	break;

	in += inChunkLen;
	out += outChunkLen;
	}

	return outLen;
	}

	uint32_t Base64Decode32(const char in, uint32_t inLen, uint8_t out)
	{
	return Base64Decode32(in, inLen, out, Base64CharToVal);
	}


	} // namespace nl

	#ifdef TEST

	#include <string.h>
	#include <stdio.h>

	void TestBase64(const char *test, bool base64URL=false)
	{
	uint8_t buf[256];
	char buf2[256];
	uint16_t len;

	strcpy((char *)buf, test);

	len = (base64URL)
	? nl::Base64URLDecode((char )buf, strlen((char )buf), buf)
	: nl::Base64Decode((char )buf, strlen((char )buf), buf);
	printf("%s: ", test);
	if (len != UINT16_MAX)
	{
	printf("(%d) ", len);
	for (uint16_t i = 0; i < len; i++)
	printf("%c", buf[i]);

	len = (base64URL)
	? nl::Base64URLEncode(buf, len, buf2)
	: nl::Base64Encode(buf, len, buf2);
	printf(" (%d) ", len);
	for (uint16_t i = 0; i < len; i++)
	printf("%c", buf2[i]);
	}
	else
	printf("ERROR");
	printf("\n");
	}

	int main(int argc, char *argv[])
	{
	TestBase64("");
	TestBase64("Zg==");
	TestBase64("Zm8=");
	TestBase64("Zm9v");
	TestBase64("Zm9vYg==");
	TestBase64("Zm9vYmE=");
	TestBase64("Zm9vYmFy");
	TestBase64("QmFzZTY0D+8xMjM0D/8=");

	TestBase64("Zg");
	TestBase64("Zm8");
	TestBase64("Zm9vYg");
	TestBase64("Zm9vYmE");

	TestBase64("QmFzZTY0D-8xMjM0D_8=", true);

	// Error cases
	TestBase64("Z");
	TestBase64("Z\x019vYmFy");
	TestBase64("Zm9vY");
	TestBase64("Zm9vY;");
	TestBase64("Zm9 vYg");
	}

	#endif // TEST