third_party/grpc/src/core/security/base64.c - bazel - Git at Google

 /*
  *
  * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */

 #include "src/core/security/base64.h"

 #include <stdint.h>
 #include <string.h>

 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/useful.h>

 /* --- Constants. --- */

 static const int8_t base64_bytes[] = {
     -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
     -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
     -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
     -1,   -1,   -1,   -1,   -1,   -1,   -1,   0x3E, -1,   -1,   -1,   0x3F,
     0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, -1,   -1,
     -1,   0x7F, -1,   -1,   -1,   0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
     0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12,
     0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, -1,   -1,   -1,   -1,   -1,
     -1,   0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24,
     0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
     0x31, 0x32, 0x33, -1,   -1,   -1,   -1,   -1};

 static const char base64_url_unsafe_chars[] =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 static const char base64_url_safe_chars[] =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";

 #define GRPC_BASE64_PAD_CHAR '='
 #define GRPC_BASE64_PAD_BYTE 0x7F
 #define GRPC_BASE64_MULTILINE_LINE_LEN 76
 #define GRPC_BASE64_MULTILINE_NUM_BLOCKS (GRPC_BASE64_MULTILINE_LINE_LEN / 4)

 /* --- base64 functions. --- */

 char *grpc_base64_encode(const void *vdata, size_t data_size, int url_safe,
                          int multiline) {
   const unsigned char *data = vdata;
   const char *base64_chars =
       url_safe ? base64_url_safe_chars : base64_url_unsafe_chars;
   size_t result_projected_size =
       4 * ((data_size + 3) / 3) +
       2 * (multiline ? (data_size / (3 * GRPC_BASE64_MULTILINE_NUM_BLOCKS))
                      : 0) +
       1;
   char *result = gpr_malloc(result_projected_size);
   char *current = result;
   size_t num_blocks = 0;
   size_t i = 0;

   /* Encode each block. */
   while (data_size >= 3) {
     *current++ = base64_chars[(data[i] >> 2) & 0x3F];
     *current++ =
         base64_chars[((data[i] & 0x03) << 4) | ((data[i + 1] >> 4) & 0x0F)];
     *current++ =
         base64_chars[((data[i + 1] & 0x0F) << 2) | ((data[i + 2] >> 6) & 0x03)];
     *current++ = base64_chars[data[i + 2] & 0x3F];

     data_size -= 3;
     i += 3;
     if (multiline && (++num_blocks == GRPC_BASE64_MULTILINE_NUM_BLOCKS)) {
       *current++ = '\r';
       *current++ = '\n';
       num_blocks = 0;
     }
   }

   /* Take care of the tail. */
   if (data_size == 2) {
     *current++ = base64_chars[(data[i] >> 2) & 0x3F];
     *current++ =
         base64_chars[((data[i] & 0x03) << 4) | ((data[i + 1] >> 4) & 0x0F)];
     *current++ = base64_chars[(data[i + 1] & 0x0F) << 2];
     *current++ = GRPC_BASE64_PAD_CHAR;
   } else if (data_size == 1) {
     *current++ = base64_chars[(data[i] >> 2) & 0x3F];
     *current++ = base64_chars[(data[i] & 0x03) << 4];
     *current++ = GRPC_BASE64_PAD_CHAR;
     *current++ = GRPC_BASE64_PAD_CHAR;
   }

   GPR_ASSERT(current >= result);
   GPR_ASSERT((uintptr_t)(current - result) < result_projected_size);
   result[current - result] = '\0';
   return result;
 }

 gpr_slice grpc_base64_decode(const char *b64, int url_safe) {
   return grpc_base64_decode_with_len(b64, strlen(b64), url_safe);
 }

 static void decode_one_char(const unsigned char *codes, unsigned char *result,
                             size_t *result_offset) {
   uint32_t packed = ((uint32_t)codes[0] << 2) | ((uint32_t)codes[1] >> 4);
   result[(*result_offset)++] = (unsigned char)packed;
 }

 static void decode_two_chars(const unsigned char *codes, unsigned char *result,
                              size_t *result_offset) {
   uint32_t packed = ((uint32_t)codes[0] << 10) | ((uint32_t)codes[1] << 4) |
                     ((uint32_t)codes[2] >> 2);
   result[(*result_offset)++] = (unsigned char)(packed >> 8);
   result[(*result_offset)++] = (unsigned char)(packed);
 }

 static int decode_group(const unsigned char *codes, size_t num_codes,
                         unsigned char *result, size_t *result_offset) {
   GPR_ASSERT(num_codes <= 4);

   /* Short end groups that may not have padding. */
   if (num_codes == 1) {
     gpr_log(GPR_ERROR, "Invalid group. Must be at least 2 bytes.");
     return 0;
   }
   if (num_codes == 2) {
     decode_one_char(codes, result, result_offset);
     return 1;
   }
   if (num_codes == 3) {
     decode_two_chars(codes, result, result_offset);
     return 1;
   }

   /* Regular 4 byte groups with padding or not. */
   GPR_ASSERT(num_codes == 4);
   if (codes[0] == GRPC_BASE64_PAD_BYTE || codes[1] == GRPC_BASE64_PAD_BYTE) {
     gpr_log(GPR_ERROR, "Invalid padding detected.");
     return 0;
   }
   if (codes[2] == GRPC_BASE64_PAD_BYTE) {
     if (codes[3] == GRPC_BASE64_PAD_BYTE) {
       decode_one_char(codes, result, result_offset);
     } else {
       gpr_log(GPR_ERROR, "Invalid padding detected.");
       return 0;
     }
   } else if (codes[3] == GRPC_BASE64_PAD_BYTE) {
     decode_two_chars(codes, result, result_offset);
   } else {
     /* No padding. */
     uint32_t packed = ((uint32_t)codes[0] << 18) | ((uint32_t)codes[1] << 12) |
                       ((uint32_t)codes[2] << 6) | codes[3];
     result[(*result_offset)++] = (unsigned char)(packed >> 16);
     result[(*result_offset)++] = (unsigned char)(packed >> 8);
     result[(*result_offset)++] = (unsigned char)(packed);
   }
   return 1;
 }

 gpr_slice grpc_base64_decode_with_len(const char *b64, size_t b64_len,
                                       int url_safe) {
   gpr_slice result = gpr_slice_malloc(b64_len);
   unsigned char *current = GPR_SLICE_START_PTR(result);
   size_t result_size = 0;
   unsigned char codes[4];
   size_t num_codes = 0;

   while (b64_len--) {
     unsigned char c = (unsigned char)(*b64++);
     signed char code;
     if (c >= GPR_ARRAY_SIZE(base64_bytes)) continue;
     if (url_safe) {
       if (c == '+' || c == '/') {
         gpr_log(GPR_ERROR, "Invalid character for url safe base64 %c", c);
         goto fail;
       }
       if (c == '-') {
         c = '+';
       } else if (c == '_') {
         c = '/';
       }
     }
     code = base64_bytes[c];
     if (code == -1) {
       if (c != '\r' && c != '\n') {
         gpr_log(GPR_ERROR, "Invalid character %c", c);
         goto fail;
       }
     } else {
       codes[num_codes++] = (unsigned char)code;
       if (num_codes == 4) {
         if (!decode_group(codes, num_codes, current, &result_size)) goto fail;
         num_codes = 0;
       }
     }
   }

   if (num_codes != 0 &&
       !decode_group(codes, num_codes, current, &result_size)) {
     goto fail;
   }
   GPR_SLICE_SET_LENGTH(result, result_size);
   return result;

 fail:
   gpr_slice_unref(result);
   return gpr_empty_slice();
 }
	/*
	*
	* Copyright 2015-2016, Google Inc.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	*
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following disclaimer
	* in the documentation and/or other materials provided with the
	* distribution.
	* * Neither the name of Google Inc. nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	*/

	#include "src/core/security/base64.h"

	#include <stdint.h>
	#include <string.h>

	#include <grpc/support/alloc.h>
	#include <grpc/support/log.h>
	#include <grpc/support/useful.h>

	/* --- Constants. --- */

	static const int8_t base64_bytes[] = {
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
	-1, -1, -1, -1, -1, -1, -1, 0x3E, -1, -1, -1, 0x3F,
	0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, -1, -1,
	-1, 0x7F, -1, -1, -1, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
	0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12,
	0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, -1, -1, -1, -1, -1,
	-1, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24,
	0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
	0x31, 0x32, 0x33, -1, -1, -1, -1, -1};

	static const char base64_url_unsafe_chars[] =
	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	static const char base64_url_safe_chars[] =
	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";

	#define GRPC_BASE64_PAD_CHAR '='
	#define GRPC_BASE64_PAD_BYTE 0x7F
	#define GRPC_BASE64_MULTILINE_LINE_LEN 76
	#define GRPC_BASE64_MULTILINE_NUM_BLOCKS (GRPC_BASE64_MULTILINE_LINE_LEN / 4)

	/* --- base64 functions. --- */

	char grpc_base64_encode(const void vdata, size_t data_size, int url_safe,
	int multiline) {
	const unsigned char *data = vdata;
	const char *base64_chars =
	url_safe ? base64_url_safe_chars : base64_url_unsafe_chars;
	size_t result_projected_size =
	4 * ((data_size + 3) / 3) +
	2 * (multiline ? (data_size / (3 * GRPC_BASE64_MULTILINE_NUM_BLOCKS))
	: 0) +
	1;
	char *result = gpr_malloc(result_projected_size);
	char *current = result;
	size_t num_blocks = 0;
	size_t i = 0;

	/* Encode each block. */
	while (data_size >= 3) {
	*current++ = base64_chars[(data[i] >> 2) & 0x3F];
	*current++ =
	base64_chars[((data[i] & 0x03) << 4) \| ((data[i + 1] >> 4) & 0x0F)];
	*current++ =
	base64_chars[((data[i + 1] & 0x0F) << 2) \| ((data[i + 2] >> 6) & 0x03)];
	*current++ = base64_chars[data[i + 2] & 0x3F];

	data_size -= 3;
	i += 3;
	if (multiline && (++num_blocks == GRPC_BASE64_MULTILINE_NUM_BLOCKS)) {
	*current++ = '\r';
	*current++ = '\n';
	num_blocks = 0;
	}
	}

	/* Take care of the tail. */
	if (data_size == 2) {
	*current++ = base64_chars[(data[i] >> 2) & 0x3F];
	*current++ =
	base64_chars[((data[i] & 0x03) << 4) \| ((data[i + 1] >> 4) & 0x0F)];
	*current++ = base64_chars[(data[i + 1] & 0x0F) << 2];
	*current++ = GRPC_BASE64_PAD_CHAR;
	} else if (data_size == 1) {
	*current++ = base64_chars[(data[i] >> 2) & 0x3F];
	*current++ = base64_chars[(data[i] & 0x03) << 4];
	*current++ = GRPC_BASE64_PAD_CHAR;
	*current++ = GRPC_BASE64_PAD_CHAR;
	}

	GPR_ASSERT(current >= result);
	GPR_ASSERT((uintptr_t)(current - result) < result_projected_size);
	result[current - result] = '\0';
	return result;
	}

	gpr_slice grpc_base64_decode(const char *b64, int url_safe) {
	return grpc_base64_decode_with_len(b64, strlen(b64), url_safe);
	}

	static void decode_one_char(const unsigned char codes, unsigned char result,
	size_t *result_offset) {
	uint32_t packed = ((uint32_t)codes[0] << 2) \| ((uint32_t)codes[1] >> 4);
	result[(*result_offset)++] = (unsigned char)packed;
	}

	static void decode_two_chars(const unsigned char codes, unsigned char result,
	size_t *result_offset) {
	uint32_t packed = ((uint32_t)codes[0] << 10) \| ((uint32_t)codes[1] << 4) \|
	((uint32_t)codes[2] >> 2);
	result[(*result_offset)++] = (unsigned char)(packed >> 8);
	result[(*result_offset)++] = (unsigned char)(packed);
	}

	static int decode_group(const unsigned char *codes, size_t num_codes,
	unsigned char result, size_t result_offset) {
	GPR_ASSERT(num_codes <= 4);

	/* Short end groups that may not have padding. */
	if (num_codes == 1) {
	gpr_log(GPR_ERROR, "Invalid group. Must be at least 2 bytes.");
	return 0;
	}
	if (num_codes == 2) {
	decode_one_char(codes, result, result_offset);
	return 1;
	}
	if (num_codes == 3) {
	decode_two_chars(codes, result, result_offset);
	return 1;
	}

	/* Regular 4 byte groups with padding or not. */
	GPR_ASSERT(num_codes == 4);
	if (codes[0] == GRPC_BASE64_PAD_BYTE \|\| codes[1] == GRPC_BASE64_PAD_BYTE) {
	gpr_log(GPR_ERROR, "Invalid padding detected.");
	return 0;
	}
	if (codes[2] == GRPC_BASE64_PAD_BYTE) {
	if (codes[3] == GRPC_BASE64_PAD_BYTE) {
	decode_one_char(codes, result, result_offset);
	} else {
	gpr_log(GPR_ERROR, "Invalid padding detected.");
	return 0;
	}
	} else if (codes[3] == GRPC_BASE64_PAD_BYTE) {
	decode_two_chars(codes, result, result_offset);
	} else {
	/* No padding. */
	uint32_t packed = ((uint32_t)codes[0] << 18) \| ((uint32_t)codes[1] << 12) \|
	((uint32_t)codes[2] << 6) \| codes[3];
	result[(*result_offset)++] = (unsigned char)(packed >> 16);
	result[(*result_offset)++] = (unsigned char)(packed >> 8);
	result[(*result_offset)++] = (unsigned char)(packed);
	}
	return 1;
	}

	gpr_slice grpc_base64_decode_with_len(const char *b64, size_t b64_len,
	int url_safe) {
	gpr_slice result = gpr_slice_malloc(b64_len);
	unsigned char *current = GPR_SLICE_START_PTR(result);
	size_t result_size = 0;
	unsigned char codes[4];
	size_t num_codes = 0;

	while (b64_len--) {
	unsigned char c = (unsigned char)(*b64++);
	signed char code;
	if (c >= GPR_ARRAY_SIZE(base64_bytes)) continue;
	if (url_safe) {
	if (c == '+' \|\| c == '/') {
	gpr_log(GPR_ERROR, "Invalid character for url safe base64 %c", c);
	goto fail;
	}
	if (c == '-') {
	c = '+';
	} else if (c == '_') {
	c = '/';
	}
	}
	code = base64_bytes[c];
	if (code == -1) {
	if (c != '\r' && c != '\n') {
	gpr_log(GPR_ERROR, "Invalid character %c", c);
	goto fail;
	}
	} else {
	codes[num_codes++] = (unsigned char)code;
	if (num_codes == 4) {
	if (!decode_group(codes, num_codes, current, &result_size)) goto fail;
	num_codes = 0;
	}
	}
	}

	if (num_codes != 0 &&
	!decode_group(codes, num_codes, current, &result_size)) {
	goto fail;
	}
	GPR_SLICE_SET_LENGTH(result, result_size);
	return result;

	fail:
	gpr_slice_unref(result);
	return gpr_empty_slice();
	}