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Diffstat (limited to 'web/server/h2o/libh2o/deps/picotls/deps/cifra/src/chash.h')
-rw-r--r-- | web/server/h2o/libh2o/deps/picotls/deps/cifra/src/chash.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/web/server/h2o/libh2o/deps/picotls/deps/cifra/src/chash.h b/web/server/h2o/libh2o/deps/picotls/deps/cifra/src/chash.h new file mode 100644 index 00000000..8f2e2012 --- /dev/null +++ b/web/server/h2o/libh2o/deps/picotls/deps/cifra/src/chash.h @@ -0,0 +1,137 @@ +/* + * cifra - embedded cryptography library + * Written in 2014 by Joseph Birr-Pixton <jpixton@gmail.com> + * + * To the extent possible under law, the author(s) have dedicated all + * copyright and related and neighboring rights to this software to the + * public domain worldwide. This software is distributed without any + * warranty. + * + * You should have received a copy of the CC0 Public Domain Dedication + * along with this software. If not, see + * <http://creativecommons.org/publicdomain/zero/1.0/>. + */ + +#ifndef CHASH_H +#define CHASH_H + +#include <stddef.h> +#include <stdint.h> + +/** + * General hash function description + * ================================= + * This allows us to make use of hash functions without depending + * on a specific one. This is useful in implementing, for example, + * :doc:`HMAC <hmac>`. + */ + +/* .. c:type:: cf_chash_init + * Hashing initialisation function type. + * + * Functions of this type should initialise the context in preparation + * for hashing a message with `cf_chash_update` functions. + * + * :rtype: void + * :param ctx: hash function-specific context structure. + */ +typedef void (*cf_chash_init)(void *ctx); + +/* .. c:type:: cf_chash_update + * Hashing data processing function type. + * + * Functions of this type hash `count` bytes of data at `data`, + * updating the contents of `ctx`. + * + * :rtype: void + * :param ctx: hash function-specific context structure. + * :param data: input data to hash. + * :param count: number of bytes to hash. + */ +typedef void (*cf_chash_update)(void *ctx, const void *data, size_t count); + +/* .. c:type:: cf_chash_digest + * Hashing completion function type. + * + * Functions of this type complete a hashing operation, + * writing :c:member:`cf_chash.hashsz` bytes to `hash`. + * + * This function does not change `ctx` -- any padding which needs doing + * must be done seperately (in a copy of `ctx`, say). + * + * This means you can interlave `_update` and `_digest` calls to + * learn `H(A)` and `H(A || B)` without hashing `A` twice. + * + * :rtype: void + * :param ctx: hash function-specific context structure. + * :param hash: location to write hash result. + */ +typedef void (*cf_chash_digest)(const void *ctx, uint8_t *hash); + +/* .. c:type:: cf_chash + * This type describes an incremental hash function in an abstract way. + * + * .. c:member:: cf_chash.hashsz + * The hash function's output, in bytes. + * + * .. c:member:: cf_chash.blocksz + * The hash function's internal block size, in bytes. + * + * .. c:member:: cf_chash.init + * Context initialisation function. + * + * .. c:member:: cf_chash:update + * Data processing function. + * + * .. c:member:: cf_chash:digest + * Completion function. + * + */ +typedef struct +{ + size_t hashsz; + size_t blocksz; + + cf_chash_init init; + cf_chash_update update; + cf_chash_digest digest; +} cf_chash; + +/* .. c:macro:: CF_CHASH_MAXCTX + * The maximum size of a :c:type:`cf_chash_ctx`. This allows + * use to put a structure in automatic storage that can + * store working data for any supported hash function. */ +#define CF_CHASH_MAXCTX 360 + +/* .. c:macro:: CF_CHASH_MAXBLK + * Maximum hash function block size (in bytes). */ +#define CF_CHASH_MAXBLK 128 + +/* .. c:macro:: CF_MAXHASH + * Maximum hash function output (in bytes). */ +#define CF_MAXHASH 64 + +/* .. c:type:: cf_chash_ctx + * A type usable with any `cf_chash` as a context. */ +typedef union +{ + uint8_t ctx[CF_CHASH_MAXCTX]; + uint16_t u16; + uint32_t u32; + uint64_t u64; +} cf_chash_ctx; + +/* .. c:function:: $DECL + * One shot hashing: `out = h(m)`. + * + * Using the hash function `h`, `nm` bytes at `m` are hashed and `h->hashsz` bytes + * of result is written to the buffer `out`. + * + * :param h: hash function description. + * :param m: message buffer. + * :param nm: message length. + * :param out: hash result buffer (written). + */ +void cf_hash(const cf_chash *h, const void *m, size_t nm, uint8_t *out); + +#endif |