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- /*
- * Copyright (C) 2008-2019 Tobias Brunner
- * Copyright (C) 2005-2008 Martin Willi
- * Copyright (C) 2005 Jan Hutter
- * HSR Hochschule fuer Technik Rapperswil
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * for more details.
- */
- /**
- * @defgroup chunk chunk
- * @{ @ingroup utils
- */
- #ifndef CHUNK_H_
- #define CHUNK_H_
- #include <string.h>
- #include <stdarg.h>
- #include <sys/types.h>
- #ifdef HAVE_ALLOCA_H
- #include <alloca.h>
- #endif
- #include <utils/utils.h>
- typedef struct chunk_t chunk_t;
- /**
- * General purpose pointer/length abstraction.
- */
- struct chunk_t {
- /** Pointer to start of data */
- u_char *ptr;
- /** Length of data in bytes */
- size_t len;
- };
- #include "utils.h"
- /**
- * A { NULL, 0 }-chunk handy for initialization.
- */
- extern chunk_t chunk_empty;
- /**
- * Create a new chunk pointing to "ptr" with length "len"
- */
- static inline chunk_t chunk_create(u_char *ptr, size_t len)
- {
- chunk_t chunk = {ptr, len};
- return chunk;
- }
- /**
- * Create a clone of a chunk pointing to "ptr"
- */
- chunk_t chunk_create_clone(u_char *ptr, chunk_t chunk);
- /**
- * Calculate length of multiple chunks
- */
- size_t chunk_length(const char *mode, ...);
- /**
- * Concatenate chunks into a chunk pointing to "ptr".
- *
- * The mode string specifies the number of chunks, and how to handle each of
- * them with a single character: 'c' for copy (allocate new chunk), 'm' for move
- * (free given chunk) or 's' for sensitive-move (clear given chunk, then free).
- */
- chunk_t chunk_create_cat(u_char *ptr, const char* mode, ...);
- /**
- * Split up a chunk into parts, "mode" is a string of "a" (alloc),
- * "c" (copy) and "m" (move). Each letter say for the corresponding chunk if
- * it should get allocated on heap, copied into existing chunk, or the chunk
- * should point into "chunk". The length of each part is an argument before
- * each target chunk. E.g.:
- * chunk_split(chunk, "mcac", 3, &a, 7, &b, 5, &c, d.len, &d);
- */
- void chunk_split(chunk_t chunk, const char *mode, ...);
- /**
- * Write the binary contents of a chunk_t to a file
- *
- * If the write fails, errno is set appropriately.
- *
- * @param chunk contents to write to file
- * @param path path where file is written to
- * @param mask file mode creation mask
- * @param force overwrite existing file by force
- * @return TRUE if write operation was successful
- */
- bool chunk_write(chunk_t chunk, char *path, mode_t mask, bool force);
- /**
- * Store data read from FD into a chunk
- *
- * On error, errno is set appropriately.
- *
- * @param fd file descriptor to read from
- * @param chunk chunk receiving allocated buffer
- * @return TRUE if successful, FALSE on failure
- */
- bool chunk_from_fd(int fd, chunk_t *chunk);
- /**
- * mmap() a file to a chunk
- *
- * The returned chunk structure is allocated from heap, but it must be freed
- * through chunk_unmap(). A user may alter the chunk ptr or len, but must pass
- * the chunk pointer returned from chunk_map() to chunk_unmap() after use.
- *
- * On error, errno is set appropriately.
- *
- * @param path path of file to map
- * @param wr TRUE to sync writes to disk
- * @return mapped chunk, NULL on error
- */
- chunk_t *chunk_map(char *path, bool wr);
- /**
- * munmap() a chunk previously mapped with chunk_map()
- *
- * When unmapping a writeable map, the return value should be checked to
- * ensure changes landed on disk.
- *
- * @param chunk pointer returned from chunk_map()
- * @return TRUE of changes written back to file
- */
- bool chunk_unmap(chunk_t *chunk);
- /**
- * Convert a chunk of data to hex encoding.
- *
- * The resulting string is '\\0' terminated, but the chunk does not include
- * the '\\0'. If buf is supplied, it must hold at least (chunk.len * 2 + 1).
- *
- * @param chunk data to convert to hex encoding
- * @param buf buffer to write to, NULL to malloc
- * @param uppercase TRUE to use uppercase letters
- * @return chunk of encoded data
- */
- chunk_t chunk_to_hex(chunk_t chunk, char *buf, bool uppercase);
- /**
- * Convert a hex encoded in a binary chunk.
- *
- * If buf is supplied, it must hold at least (hex.len / 2) + (hex.len % 2)
- * bytes. It is filled by the right to give correct values for short inputs.
- *
- * @param hex hex encoded input data
- * @param buf buffer to write decoded data, NULL to malloc
- * @return converted data
- */
- chunk_t chunk_from_hex(chunk_t hex, char *buf);
- /**
- * Convert a chunk of data to its base64 encoding.
- *
- * The resulting string is '\\0' terminated, but the chunk does not include
- * the '\\0'. If buf is supplied, it must hold at least (chunk.len * 4 / 3 + 1).
- *
- * @param chunk data to convert
- * @param buf buffer to write to, NULL to malloc
- * @return chunk of encoded data
- */
- chunk_t chunk_to_base64(chunk_t chunk, char *buf);
- /**
- * Convert a base64 in a binary chunk.
- *
- * If buf is supplied, it must hold at least (base64.len / 4 * 3).
- *
- * @param base64 base64 encoded input data
- * @param buf buffer to write decoded data, NULL to malloc
- * @return converted data
- */
- chunk_t chunk_from_base64(chunk_t base64, char *buf);
- /**
- * Convert a chunk of data to its base32 encoding.
- *
- * The resulting string is '\\0' terminated, but the chunk does not include
- * the '\\0'. If buf is supplied, it must hold (chunk.len * 8 / 5 + 1) bytes.
- *
- * @param chunk data to convert
- * @param buf buffer to write to, NULL to malloc
- * @return chunk of encoded data
- */
- chunk_t chunk_to_base32(chunk_t chunk, char *buf);
- /**
- * Free contents of a chunk
- */
- static inline void chunk_free(chunk_t *chunk)
- {
- free(chunk->ptr);
- *chunk = chunk_empty;
- }
- /**
- * Overwrite the contents of a chunk and free it
- */
- static inline void chunk_clear(chunk_t *chunk)
- {
- if (chunk->ptr)
- {
- memwipe(chunk->ptr, chunk->len);
- chunk_free(chunk);
- }
- }
- /**
- * Initialize a chunk using a char array
- */
- #define chunk_from_chars(...) ((chunk_t){(u_char[]){__VA_ARGS__}, sizeof((u_char[]){__VA_ARGS__})})
- /**
- * Initialize a chunk to point to a thing
- */
- #define chunk_from_thing(thing) chunk_create((u_char*)&(thing), sizeof(thing))
- /**
- * Initialize a chunk from a string, not containing 0-terminator
- */
- #define chunk_from_str(str) ({char *x = (str); chunk_create((u_char*)x, strlen(x));})
- /**
- * Allocate a chunk on the heap
- */
- #define chunk_alloc(bytes) ({size_t x = (bytes); chunk_create(x ? malloc(x) : NULL, x);})
- /**
- * Allocate a chunk on the stack
- */
- #define chunk_alloca(bytes) ({size_t x = (bytes); chunk_create(x ? alloca(x) : NULL, x);})
- /**
- * Clone a chunk on heap
- */
- #define chunk_clone(chunk) ({chunk_t x = (chunk); chunk_create_clone(x.len ? malloc(x.len) : NULL, x);})
- /**
- * Clone a chunk on stack
- */
- #define chunk_clonea(chunk) ({chunk_t x = (chunk); chunk_create_clone(x.len ? alloca(x.len) : NULL, x);})
- /**
- * Concatenate chunks into a chunk on heap
- */
- #define chunk_cat(mode, ...) chunk_create_cat(malloc(chunk_length(mode, __VA_ARGS__)), mode, __VA_ARGS__)
- /**
- * Concatenate chunks into a chunk on stack
- */
- #define chunk_cata(mode, ...) chunk_create_cat(alloca(chunk_length(mode, __VA_ARGS__)), mode, __VA_ARGS__)
- /**
- * Skip n bytes in chunk (forward pointer, shorten length)
- */
- static inline chunk_t chunk_skip(chunk_t chunk, size_t bytes)
- {
- if (chunk.len > bytes)
- {
- chunk.ptr += bytes;
- chunk.len -= bytes;
- return chunk;
- }
- return chunk_empty;
- }
- /**
- * Skip any leading zero-valued bytes
- */
- static inline chunk_t chunk_skip_zero(chunk_t chunk)
- {
- while (chunk.len > 1 && *chunk.ptr == 0x00)
- {
- chunk.ptr++;
- chunk.len--;
- }
- return chunk;
- }
- /**
- * Copy the data from src to dst, left-padded with chr if dst is longer,
- * otherwise data is copied truncated on the left.
- *
- * @param dst data is copied here
- * @param src data is copied from here
- * @param chr value to use for padding if necessary
- * @return the destination chunk
- */
- chunk_t chunk_copy_pad(chunk_t dst, chunk_t src, u_char chr);
- /**
- * Compare two chunks, returns zero if a equals b
- * or negative/positive if a is small/greater than b
- */
- int chunk_compare(chunk_t a, chunk_t b);
- /**
- * Compare two chunks for equality,
- * NULL chunks are never equal.
- */
- static inline bool chunk_equals(chunk_t a, chunk_t b)
- {
- return a.ptr != NULL && b.ptr != NULL &&
- a.len == b.len && memeq(a.ptr, b.ptr, a.len);
- }
- /**
- * Compare two chunks for equality, constant time for cryptographic purposes.
- *
- * Note that this function is constant time only for chunks with the same
- * length, i.e. it does not protect against guessing the length of one of the
- * chunks.
- */
- static inline bool chunk_equals_const(chunk_t a, chunk_t b)
- {
- return a.ptr != NULL && b.ptr != NULL &&
- a.len == b.len && memeq_const(a.ptr, b.ptr, a.len);
- }
- /**
- * Compare two chunks (given as pointers) for equality (useful as callback),
- * NULL chunks are never equal.
- */
- static inline bool chunk_equals_ptr(chunk_t *a, chunk_t *b)
- {
- return a != NULL && b != NULL && chunk_equals(*a, *b);
- }
- /**
- * Increment a chunk, as it would represent a network order integer.
- *
- * @param chunk chunk to increment
- * @return TRUE if an overflow occurred
- */
- bool chunk_increment(chunk_t chunk);
- /**
- * Check if a chunk has printable characters only.
- *
- * If sane is given, chunk is cloned into sane and all non printable characters
- * get replaced by "replace".
- *
- * @param chunk chunk to check for printability
- * @param sane pointer where sane version is allocated, or NULL
- * @param replace character to use for replaceing unprintable characters
- * @return TRUE if all characters in chunk are printable
- */
- bool chunk_printable(chunk_t chunk, chunk_t *sane, char replace);
- /**
- * Seed initial key for chunk_hash().
- *
- * This call should get invoked once during startup. This is usually done
- * by calling library_init(). Calling it multiple times is safe, it gets
- * executed just once.
- */
- void chunk_hash_seed();
- /**
- * Computes a 32 bit hash of the given chunk.
- *
- * @note The output of this function is randomized, that is, it will only
- * produce the same output for the same input when calling it from the same
- * process. For a more predictable hash function use chunk_hash_static()
- * instead.
- *
- * @note This hash is only intended for hash tables not for cryptographic
- * purposes.
- *
- * @param chunk data to hash
- * @return hash value
- */
- uint32_t chunk_hash(chunk_t chunk);
- /**
- * Incremental version of chunk_hash. Use this to hash two or more chunks.
- *
- * @param chunk data to hash
- * @param hash previous hash value
- * @return hash value
- */
- uint32_t chunk_hash_inc(chunk_t chunk, uint32_t hash);
- /**
- * Computes a 32 bit hash of the given chunk.
- *
- * Compared to chunk_hash() this will always calculate the same output for the
- * same input. Therefore, it should not be used for hash tables (to prevent
- * hash flooding).
- *
- * @note This hash is not intended for cryptographic purposes.
- *
- * @param chunk data to hash
- * @return hash value
- */
- uint32_t chunk_hash_static(chunk_t chunk);
- /**
- * Incremental version of chunk_hash_static(). Use this to hash two or more
- * chunks in a predictable way.
- *
- * @param chunk data to hash
- * @param hash previous hash value
- * @return hash value
- */
- uint32_t chunk_hash_static_inc(chunk_t chunk, uint32_t hash);
- /**
- * Computes a quick MAC from the given chunk and key using SipHash.
- *
- * The key must have a length of 128-bit (16 bytes).
- *
- * @note While SipHash has strong features using it for cryptographic purposes
- * is not recommended (in particular because of the rather short output size).
- *
- * @param chunk data to process
- * @param key key to use
- * @return MAC for given input and key
- */
- uint64_t chunk_mac(chunk_t chunk, u_char *key);
- /**
- * Calculate the Internet Checksum according to RFC 1071 for the given chunk.
- *
- * If the result is used with chunk_internet_checksum_inc() and the data length
- * is not a multiple of 16 bit the checksum bytes have to be swapped to
- * compensate the even/odd alignment.
- *
- * @param data data to process
- * @return checksum (one's complement, network order)
- */
- uint16_t chunk_internet_checksum(chunk_t data);
- /**
- * Extend the given Internet Checksum (one's complement, in network byte order)
- * with the given data.
- *
- * If data is not a multiple of 16 bits the checksum may have to be swapped to
- * compensate even/odd alignment (see chunk_internet_checksum()).
- *
- * @param data data to process
- * @param checksum previous checksum (one's complement, network order)
- * @return checksum (one's complement, network order)
- */
- uint16_t chunk_internet_checksum_inc(chunk_t data, uint16_t checksum);
- /**
- * printf hook function for chunk_t.
- *
- * Arguments are:
- * chunk_t *chunk
- * Use #-modifier to print a compact version
- * Use +-modifier to print a compact version without separator
- */
- int chunk_printf_hook(printf_hook_data_t *data, printf_hook_spec_t *spec,
- const void *const *args);
- #endif /** CHUNK_H_ @}*/
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