include/openssl/base64.h - boringssl - Git at Google

 // Copyright 1995-2016 The OpenSSL Project Authors. 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
 //
 //     https://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.

 #ifndef OPENSSL_HEADER_BASE64_H
 #define OPENSSL_HEADER_BASE64_H

 #include <openssl/base.h>

 #if defined(__cplusplus)
 extern "C" {
 #endif


 // base64 functions.
 //
 // For historical reasons, these functions have the EVP_ prefix but just do
 // base64 encoding and decoding. Note that BoringSSL is a cryptography library,
 // so these functions are implemented with side channel protections, at a
 // performance cost. For other base64 uses, use a general-purpose base64
 // implementation.


 // Encoding

 // EVP_EncodeBlock encodes |src_len| bytes from |src| and writes the
 // result to |dst| with a trailing NUL. It returns the number of bytes
 // written, not including this trailing NUL.
 OPENSSL_EXPORT size_t EVP_EncodeBlock(uint8_t *dst, const uint8_t *src,
                                       size_t src_len);

 // EVP_EncodedLength sets |*out_len| to the number of bytes that will be needed
 // to call |EVP_EncodeBlock| on an input of length |len|. This includes the
 // final NUL that |EVP_EncodeBlock| writes. It returns one on success or zero
 // on error.
 OPENSSL_EXPORT int EVP_EncodedLength(size_t *out_len, size_t len);


 // Decoding

 // EVP_DecodedLength sets |*out_len| to the maximum number of bytes that will
 // be needed to call |EVP_DecodeBase64| on an input of length |len|. It returns
 // one on success or zero if |len| is not a valid length for a base64-encoded
 // string.
 OPENSSL_EXPORT int EVP_DecodedLength(size_t *out_len, size_t len);

 // EVP_DecodeBase64 decodes |in_len| bytes from base64 and writes
 // |*out_len| bytes to |out|. |max_out| is the size of the output
 // buffer. If it is not enough for the maximum output size, the
 // operation fails. It returns one on success or zero on error.
 OPENSSL_EXPORT int EVP_DecodeBase64(uint8_t *out, size_t *out_len,
                                     size_t max_out, const uint8_t *in,
                                     size_t in_len);


 // Deprecated functions.
 //
 // OpenSSL provides a streaming base64 implementation, however its behavior is
 // very specific to PEM. It is also very lenient of invalid input. Use of any of
 // these functions is thus deprecated.

 // EVP_ENCODE_CTX_new returns a newly-allocated |EVP_ENCODE_CTX| or NULL on
 // error. The caller must release the result with |EVP_ENCODE_CTX_free|  when
 // done.
 OPENSSL_EXPORT EVP_ENCODE_CTX *EVP_ENCODE_CTX_new(void);

 // EVP_ENCODE_CTX_free releases memory associated with |ctx|.
 OPENSSL_EXPORT void EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx);

 // EVP_EncodeInit initialises |*ctx|, which is typically stack
 // allocated, for an encoding operation.
 //
 // NOTE: The encoding operation breaks its output with newlines every
 // 64 characters of output (48 characters of input). Use
 // EVP_EncodeBlock to encode raw base64.
 OPENSSL_EXPORT void EVP_EncodeInit(EVP_ENCODE_CTX *ctx);

 // EVP_EncodeUpdate encodes |in_len| bytes from |in| and writes an encoded
 // version of them to |out| and sets |*out_len| to the number of bytes written.
 // Some state may be contained in |ctx| so |EVP_EncodeFinal| must be used to
 // flush it before using the encoded data.
 OPENSSL_EXPORT void EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, uint8_t *out,
                                      int *out_len, const uint8_t *in,
                                      size_t in_len);

 // EVP_EncodeFinal flushes any remaining output bytes from |ctx| to |out| and
 // sets |*out_len| to the number of bytes written.
 OPENSSL_EXPORT void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, uint8_t *out,
                                     int *out_len);

 // EVP_DecodeInit initialises |*ctx|, which is typically stack allocated, for
 // a decoding operation.
 //
 // TODO(davidben): This isn't a straight-up base64 decode either. Document
 // and/or fix exactly what's going on here; maximum line length and such.
 OPENSSL_EXPORT void EVP_DecodeInit(EVP_ENCODE_CTX *ctx);

 // EVP_DecodeUpdate decodes |in_len| bytes from |in| and writes the decoded
 // data to |out| and sets |*out_len| to the number of bytes written. Some state
 // may be contained in |ctx| so |EVP_DecodeFinal| must be used to flush it
 // before using the encoded data.
 //
 // It returns -1 on error, one if a full line of input was processed and zero
 // if the line was short (i.e. it was the last line).
 OPENSSL_EXPORT int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, uint8_t *out,
                                     int *out_len, const uint8_t *in,
                                     size_t in_len);

 // EVP_DecodeFinal flushes any remaining output bytes from |ctx| to |out| and
 // sets |*out_len| to the number of bytes written. It returns one on success
 // and minus one on error.
 OPENSSL_EXPORT int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, uint8_t *out,
                                    int *out_len);

 // EVP_DecodeBlock encodes |src_len| bytes from |src| and writes the result to
 // |dst|. It returns the number of bytes written or -1 on error.
 //
 // WARNING: EVP_DecodeBlock's return value does not take padding into
 // account. It also strips leading whitespace and trailing
 // whitespace and minuses.
 OPENSSL_EXPORT int EVP_DecodeBlock(uint8_t *dst, const uint8_t *src,
                                    size_t src_len);


 struct evp_encode_ctx_st {
   // data_used indicates the number of bytes of |data| that are valid. When
   // encoding, |data| will be filled and encoded as a lump. When decoding, only
   // the first four bytes of |data| will be used.
   unsigned data_used;
   uint8_t data[48];

   // eof_seen indicates that the end of the base64 data has been seen when
   // decoding. Only whitespace can follow.
   char eof_seen;

   // error_encountered indicates that invalid base64 data was found. This will
   // cause all future calls to fail.
   char error_encountered;
 };


 #if defined(__cplusplus)
 }  // extern C
 #endif

 #endif  // OPENSSL_HEADER_BASE64_H
	// Copyright 1995-2016 The OpenSSL Project Authors. 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
	//
	// https://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.

	#ifndef OPENSSL_HEADER_BASE64_H
	#define OPENSSL_HEADER_BASE64_H

	#include <openssl/base.h>

	#if defined(__cplusplus)
	extern "C" {
	#endif


	// base64 functions.
	//
	// For historical reasons, these functions have the EVP_ prefix but just do
	// base64 encoding and decoding. Note that BoringSSL is a cryptography library,
	// so these functions are implemented with side channel protections, at a
	// performance cost. For other base64 uses, use a general-purpose base64
	// implementation.


	// Encoding

	// EVP_EncodeBlock encodes \|src_len\| bytes from \|src\| and writes the
	// result to \|dst\| with a trailing NUL. It returns the number of bytes
	// written, not including this trailing NUL.
	OPENSSL_EXPORT size_t EVP_EncodeBlock(uint8_t dst, const uint8_t src,
	size_t src_len);

	// EVP_EncodedLength sets \|*out_len\| to the number of bytes that will be needed
	// to call \|EVP_EncodeBlock\| on an input of length \|len\|. This includes the
	// final NUL that \|EVP_EncodeBlock\| writes. It returns one on success or zero
	// on error.
	OPENSSL_EXPORT int EVP_EncodedLength(size_t *out_len, size_t len);


	// Decoding

	// EVP_DecodedLength sets \|*out_len\| to the maximum number of bytes that will
	// be needed to call \|EVP_DecodeBase64\| on an input of length \|len\|. It returns
	// one on success or zero if \|len\| is not a valid length for a base64-encoded
	// string.
	OPENSSL_EXPORT int EVP_DecodedLength(size_t *out_len, size_t len);

	// EVP_DecodeBase64 decodes \|in_len\| bytes from base64 and writes
	// \|*out_len\| bytes to \|out\|. \|max_out\| is the size of the output
	// buffer. If it is not enough for the maximum output size, the
	// operation fails. It returns one on success or zero on error.
	OPENSSL_EXPORT int EVP_DecodeBase64(uint8_t out, size_t out_len,
	size_t max_out, const uint8_t *in,
	size_t in_len);


	// Deprecated functions.
	//
	// OpenSSL provides a streaming base64 implementation, however its behavior is
	// very specific to PEM. It is also very lenient of invalid input. Use of any of
	// these functions is thus deprecated.

	// EVP_ENCODE_CTX_new returns a newly-allocated \|EVP_ENCODE_CTX\| or NULL on
	// error. The caller must release the result with \|EVP_ENCODE_CTX_free\| when
	// done.
	OPENSSL_EXPORT EVP_ENCODE_CTX *EVP_ENCODE_CTX_new(void);

	// EVP_ENCODE_CTX_free releases memory associated with \|ctx\|.
	OPENSSL_EXPORT void EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx);

	// EVP_EncodeInit initialises \|*ctx\|, which is typically stack
	// allocated, for an encoding operation.
	//
	// NOTE: The encoding operation breaks its output with newlines every
	// 64 characters of output (48 characters of input). Use
	// EVP_EncodeBlock to encode raw base64.
	OPENSSL_EXPORT void EVP_EncodeInit(EVP_ENCODE_CTX *ctx);

	// EVP_EncodeUpdate encodes \|in_len\| bytes from \|in\| and writes an encoded
	// version of them to \|out\| and sets \|*out_len\| to the number of bytes written.
	// Some state may be contained in \|ctx\| so \|EVP_EncodeFinal\| must be used to
	// flush it before using the encoded data.
	OPENSSL_EXPORT void EVP_EncodeUpdate(EVP_ENCODE_CTX ctx, uint8_t out,
	int out_len, const uint8_t in,
	size_t in_len);

	// EVP_EncodeFinal flushes any remaining output bytes from \|ctx\| to \|out\| and
	// sets \|*out_len\| to the number of bytes written.
	OPENSSL_EXPORT void EVP_EncodeFinal(EVP_ENCODE_CTX ctx, uint8_t out,
	int *out_len);

	// EVP_DecodeInit initialises \|*ctx\|, which is typically stack allocated, for
	// a decoding operation.
	//
	// TODO(davidben): This isn't a straight-up base64 decode either. Document
	// and/or fix exactly what's going on here; maximum line length and such.
	OPENSSL_EXPORT void EVP_DecodeInit(EVP_ENCODE_CTX *ctx);

	// EVP_DecodeUpdate decodes \|in_len\| bytes from \|in\| and writes the decoded
	// data to \|out\| and sets \|*out_len\| to the number of bytes written. Some state
	// may be contained in \|ctx\| so \|EVP_DecodeFinal\| must be used to flush it
	// before using the encoded data.
	//
	// It returns -1 on error, one if a full line of input was processed and zero
	// if the line was short (i.e. it was the last line).
	OPENSSL_EXPORT int EVP_DecodeUpdate(EVP_ENCODE_CTX ctx, uint8_t out,
	int out_len, const uint8_t in,
	size_t in_len);

	// EVP_DecodeFinal flushes any remaining output bytes from \|ctx\| to \|out\| and
	// sets \|*out_len\| to the number of bytes written. It returns one on success
	// and minus one on error.
	OPENSSL_EXPORT int EVP_DecodeFinal(EVP_ENCODE_CTX ctx, uint8_t out,
	int *out_len);

	// EVP_DecodeBlock encodes \|src_len\| bytes from \|src\| and writes the result to
	// \|dst\|. It returns the number of bytes written or -1 on error.
	//
	// WARNING: EVP_DecodeBlock's return value does not take padding into
	// account. It also strips leading whitespace and trailing
	// whitespace and minuses.
	OPENSSL_EXPORT int EVP_DecodeBlock(uint8_t dst, const uint8_t src,
	size_t src_len);


	struct evp_encode_ctx_st {
	// data_used indicates the number of bytes of \|data\| that are valid. When
	// encoding, \|data\| will be filled and encoded as a lump. When decoding, only
	// the first four bytes of \|data\| will be used.
	unsigned data_used;
	uint8_t data[48];

	// eof_seen indicates that the end of the base64 data has been seen when
	// decoding. Only whitespace can follow.
	char eof_seen;

	// error_encountered indicates that invalid base64 data was found. This will
	// cause all future calls to fail.
	char error_encountered;
	};


	#if defined(__cplusplus)
	} // extern C
	#endif

	#endif // OPENSSL_HEADER_BASE64_H