/*
* Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef BR_BEARSSL_HASH_H__
#define BR_BEARSSL_HASH_H__
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#ifdef __cplusplus
extern "C" {
#endif
/** \file bearssl_hash.h
*
* # Hash Functions
*
* This file documents the API for hash functions.
*
*
* ## Procedural API
*
* For each implemented hash function, of name "`xxx`", the following
* elements are defined:
*
* - `br_xxx_vtable`
*
* An externally defined instance of `br_hash_class`.
*
* - `br_xxx_SIZE`
*
* A macro that evaluates to the output size (in bytes) of the
* hash function.
*
* - `br_xxx_ID`
*
* A macro that evaluates to a symbolic identifier for the hash
* function. Such identifiers are used with HMAC and signature
* algorithm implementations.
*
* NOTE: for the "standard" hash functions defined in [the TLS
* standard](https://tools.ietf.org/html/rfc5246#section-7.4.1.4.1),
* the symbolic identifiers match the constants used in TLS, i.e.
* 1 to 6 for MD5, SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512,
* respectively.
*
* - `br_xxx_context`
*
* Context for an ongoing computation. It is allocated by the
* caller, and a pointer to it is passed to all functions. A
* context contains no interior pointer, so it can be moved around
* and cloned (with a simple `memcpy()` or equivalent) in order to
* capture the function state at some point. Computations that use
* distinct context structures are independent of each other. The
* first field of `br_xxx_context` is always a pointer to the
* `br_xxx_vtable` structure; `br_xxx_init()` sets that pointer.
*
* - `br_xxx_init(br_xxx_context *ctx)`
*
* Initialise the provided context. Previous contents of the structure
* are ignored. This calls resets the context to the start of a new
* hash computation; it also sets the first field of the context
* structure (called `vtable`) to a pointer to the statically
* allocated constant `br_xxx_vtable` structure.
*
* - `br_xxx_update(br_xxx_context *ctx, const void *data, size_t len)`
*
* Add some more bytes to the hash computation represented by the
* provided context.
*
* - `br_xxx_out(const br_xxx_context *ctx, void *out)`
*
* Complete the hash computation and write the result in the provided
* buffer. The output buffer MUST be large enough to accommodate the
* result. The context is NOT modified by this operation, so this
* function can be used to get a "partial hash" while still keeping
* the possibility of adding more bytes to the input.
*
* - `br_xxx_state(const br_xxx_context *ctx, void *out)`
*
* Get a copy of the "current state" for the computation so far. For
* MD functions (MD5, SHA-1, SHA-2 family), this is the running state
* resulting from the processing of the last complete input block.
* Returned value is the current input length (in bytes).
*
* - `br_xxx_set_state(br_xxx_context *ctx, const void *stb, uint64_t count)`
*
* Set the internal state to the provided values. The 'stb' and
* 'count' values shall match that which was obtained from
* `br_xxx_state()`. This restores the hash state only if the state
* values were at an appropriate block boundary. This does NOT set
* the `vtable` pointer in the context.
*
* Context structures can be discarded without any explicit deallocation.
* Hash function implementations are purely software and don't reserve
* any resources outside of the context structure itself.
*
*
* ## Object-Oriented API
*
* For each hash function that follows the procedural API described
* above, an object-oriented API is also provided. In that API, function
* pointers from the vtable (`br_xxx_vtable`) are used. The vtable
* incarnates object-oriented programming. An introduction on the OOP
* concept used here can be read on the BearSSL Web site:<br />
* [https://www.bearssl.org/oop.html](https://www.bearssl.org/oop.html)
*
* The vtable offers functions called `init()`, `update()`, `out()`,
* `set()` and `set_state()`, which are in fact the functions from
* the procedural API. That vtable also contains two informative fields:
*
* - `context_size`
*
* The size of the context structure (`br_xxx_context`), in bytes.
* This can be used by generic implementations to perform dynamic
* context allocation.
*
* - `desc`
*
* A "descriptor" field that encodes some information on the hash
* function: symbolic identifier, output size, state size,
* internal block size, details on the padding.
*
* Users of this object-oriented API (in particular generic HMAC
* implementations) may make the following assumptions:
*
* - Hash output size is no more than 64 bytes.
* - Hash internal state size is no more than 64 bytes.
* - Internal block size is a power of two, no less than 16 and no more
* than 256.
*
*
* ## Implemented Hash Functions
*
* Implemented hash functions are:
*
* | Function | Name | Output length | State length |
* | :-------- | :------ | :-----------: | :----------: |
* | MD5 | md5 | 16 | 16 |
* | SHA-1 | sha1 | 20 | 20 |
* | SHA-224 | sha224 | 28 | 32 |
* | SHA-256 | sha256 | 32 | 32 |
* | SHA-384 | sha384 | 48 | 64 |
* | SHA-512 | sha512 | 64 | 64 |
* | MD5+SHA-1 | md5sha1 | 36 | 36 |
*
* (MD5+SHA-1 is the concatenation of MD5 and SHA-1 computed over the
* same input; in the implementation, the internal data buffer is
* shared, thus making it more memory-efficient than separate MD5 and
* SHA-1. It can be useful in implementing SSL 3.0, TLS 1.0 and TLS
* 1.1.)
*
*
* ## Multi-Hasher
*
* An aggregate hasher is provided, that can compute several standard
* hash functions in parallel. It uses `br_multihash_context` and a
* procedural API. It is configured with the implementations (the vtables)
* that it should use; it will then compute all these hash functions in
* parallel, on the same input. It is meant to be used in cases when the
* hash of an object will be used, but the exact hash function is not
* known yet (typically, streamed processing on X.509 certificates).
*
* Only the standard hash functions (MD5, SHA-1, SHA-224, SHA-256, SHA-384
* and SHA-512) are supported by the multi-hasher.
*
*
* ## GHASH
*
* GHASH is not a generic hash function; it is a _universal_ hash function,
* which, as the name does not say, means that it CANNOT be used in most
* places where a hash function is needed. GHASH is used within the GCM
* encryption mode, to provide the checked integrity functionality.
*
* A GHASH implementation is basically a function that uses the type defined
* in this file under the name `br_ghash`:
*
* typedef void (*br_ghash)(void *y, const void *h, const void *data, size_t len);
*
* The `y` pointer refers to a 16-byte value which is used as input, and
* receives the output of the GHASH invocation. `h` is a 16-byte secret
* value (that serves as key). `data` and `len` define the input data.
*
* Three GHASH implementations are provided, all constant-time, based on
* the use of integer multiplications with appropriate masking to cancel
* carry propagation.
*/
/**
* \brief Class type for hash function implementations.
*
* A `br_hash_class` instance references the methods implementing a hash
* function. Constant instances of this structure are defined for each
* implemented hash function. Such instances are also called "vtables".
*
* Vtables are used to support object-oriented programming, as
* described on [the BearSSL Web site](https://www.bearssl.org/oop.html).
*/
typedef struct br_hash_class_ br_hash_class;
struct br_hash_class_ {
/**
* \brief Size (in bytes) of the context structure appropriate for
* computing this hash function.
*/
size_t context_size;
/**
* \brief Descriptor word that contains information about the hash
* function.
*
* For each word `xxx` described below, use `BR_HASHDESC_xxx_OFF`
* and `BR_HASHDESC_xxx_MASK` to access the specific value, as
* follows:
*
* (hf->desc >> BR_HASHDESC_xxx_OFF) & BR_HASHDESC_xxx_MASK
*
* The defined elements are:
*
* - `ID`: the symbolic identifier for the function, as defined
* in [TLS](https://tools.ietf.org/html/rfc5246#section-7.4.1.4.1)
* (MD5 = 1, SHA-1 = 2,...).
*
* - `OUT`: hash output size, in bytes.
*
* - `STATE`: internal running state size, in bytes.
*
* - `LBLEN`: base-2 logarithm for the internal block size, as
* defined for HMAC processing (this is 6 for MD5, SHA-1, SHA-224
* and SHA-256, since these functions use 64-byte blocks; for
* SHA-384 and SHA-512, this is 7, corresponding to their
* 128-byte blocks).
*
* The descriptor may contain a few other flags.
*/
uint32_t desc;
/**
* \brief Initialisation method.
*
* This method takes as parameter a pointer to a context area,
* that it initialises. The first field of the context is set
* to this vtable; other elements are initialised for a new hash
* computation.
*
* \param ctx pointer to (the first field of) the context.
*/
void (*init)(const br_hash_class **ctx);
/**
* \brief Data injection method.
*
* The `len` bytes starting at address `data` are injected into
* the running hash computation incarnated by the specified
* context. The context is updated accordingly. It is allowed
* to have `len == 0`, in which case `data` is ignored (and could
* be `NULL`), and nothing happens.
* on the input data.
*
* \param ctx pointer to (the first field of) the context.
* \param data pointer to the first data byte to inject.
* \param len number of bytes to inject.
*/
void (*update)(const br_hash_class **ctx, const void *data, size_t len);
/**
* \brief Produce hash output.
*
* The hash output corresponding to all data bytes injected in the
* context since the last `init()` call is computed, and written
* in the buffer pointed to by `dst`. The hash output size depends
* on the implemented hash function (e.g. 16 bytes for MD5).
* The context is _not_ modified by this call, so further bytes
* may be afterwards injected to continue the current computation.
*
* \param ctx pointer to (the first field of) the context.
* \param dst destination buffer for the hash output.
*/
void (*out)(const br_hash_class *const *ctx, void *dst);
/**
* \brief Get running state.
*
* This method saves the current running state into the `dst`
* buffer. What constitutes the "running state" depends on the
* hash function; for Merkle-Damgård hash functions (like
* MD5 or SHA-1), this is the output obtained after processing
* each block. The number of bytes injected so far is returned.
* The context is not modified by this call.
*
* \param ctx pointer to (the first field of) the context.
* \param dst destination buffer for the state.
* \return the injected total byte length.
*/
uint64_t (*state)(const br_hash_class *const *ctx, void *dst);
/**
* \brief Set running state.
*
* This methods replaces the running state for the function.
*
* \param ctx pointer to (the first field of) the context.
* \param stb source buffer for the state.
* \param count injected total byte length.
*/
void (*set_state)(const br_hash_class **ctx,
const void *stb, uint64_t count);
};
#ifndef BR_DOXYGEN_IGNORE
#define BR_HASHDESC_ID(id) ((uint32_t)(id) << BR_HASHDESC_ID_OFF)
#define BR_HASHDESC_ID_OFF 0
#define BR_HASHDESC_ID_MASK 0xFF
#define BR_HASHDESC_OUT(size) ((uint32_t)(size) << BR_HASHDESC_OUT_OFF)
#define BR_HASHDESC_OUT_OFF 8
#define BR_HASHDESC_OUT_MASK 0x7F
#define BR_HASHDESC_STATE(size) ((uint32_t)(size) << BR_HASHDESC_STATE_OFF)
#define BR_HASHDESC_STATE_OFF 15
#define BR_HASHDESC_STATE_MASK 0xFF
#define BR_HASHDESC_LBLEN(ls) ((uint32_t)(ls) << BR_HASHDESC_LBLEN_OFF)
#define BR_HASHDESC_LBLEN_OFF 23
#define BR_HASHDESC_LBLEN_MASK 0x0F
#define BR_HASHDESC_MD_PADDING ((uint32_t)1 << 28)
#define BR_HASHDESC_MD_PADDING_128 ((uint32_t)1 << 29)
#define BR_HASHDESC_MD_PADDING_BE ((uint32_t)1 << 30)
#endif
/*
* Specific hash functions.
*
* Rules for contexts:
* -- No interior pointer.
* -- No pointer to external dynamically allocated resources.
* -- First field is called 'vtable' and is a pointer to a
* const-qualified br_hash_class instance (pointer is set by init()).
* -- SHA-224 and SHA-256 contexts are identical.
* -- SHA-384 and SHA-512 contexts are identical.
*
* Thus, contexts can be moved and cloned to capture the hash function
* current state; and there is no need for any explicit "release" function.
*/
/**
* \brief Symbolic identifier for MD5.
*/
#define br_md5_ID 1
/**
* \brief MD5 output size (in bytes).
*/
#define br_md5_SIZE 16
/**
* \brief Constant vtable for MD5.
*/
extern const br_hash_class br_md5_vtable;
/**
* \brief MD5 context.
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/**
* \brief Pointer to vtable for this context.
*/
const br_hash_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
unsigned char buf[64];
uint64_t count;
uint32_t val[4];
#endif
} br_md5_context;
/**
* \brief MD5 context initialisation.
*
* This function initialises or resets a context for a new MD5
* computation. It also sets the vtable pointer.
*
* \param ctx pointer to the context structure.
*/
void br_md5_init(br_md5_context *ctx);
/**
* \brief Inject some data bytes in a running MD5 computation.
*
* The provided context is updated with some data bytes. If the number
* of bytes (`len`) is zero, then the data pointer (`data`) is ignored
* and may be `NULL`, and this function does nothing.
*
* \param ctx pointer to the context structure.
* \param data pointer to the injected data.
* \param len injected data length (in bytes).
*/
void br_md5_update(br_md5_context *ctx, const void *data, size_t len);
/**
* \brief Compute MD5 output.
*
* The MD5 output for the concatenation of all bytes injected in the
* provided context since the last initialisation or reset call, is
* computed and written in the buffer pointed to by `out`. The context
* itself is not modified, so extra bytes may be injected afterwards
* to continue that computation.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the hash output.
*/
void br_md5_out(const br_md5_context *ctx, void *out);
/**
* \brief Save MD5 running state.
*
* The running state for MD5 (output of the last internal block
* processing) is written in the buffer pointed to by `out`. The
* number of bytes injected since the last initialisation or reset
* call is returned. The context is not modified.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the running state.
* \return the injected total byte length.
*/
uint64_t br_md5_state(const br_md5_context *ctx, void *out);
/**
* \brief Restore MD5 running state.
*
* The running state for MD5 is set to the provided values.
*
* \param ctx pointer to the context structure.
* \param stb source buffer for the running state.
* \param count the injected total byte length.
*/
void br_md5_set_state(br_md5_context *ctx, const void *stb, uint64_t count);
/**
* \brief Symbolic identifier for SHA-1.
*/
#define br_sha1_ID 2
/**
* \brief SHA-1 output size (in bytes).
*/
#define br_sha1_SIZE 20
/**
* \brief Constant vtable for SHA-1.
*/
extern const br_hash_class br_sha1_vtable;
/**
* \brief SHA-1 context.
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/**
* \brief Pointer to vtable for this context.
*/
const br_hash_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
unsigned char buf[64];
uint64_t count;
uint32_t val[5];
#endif
} br_sha1_context;
/**
* \brief SHA-1 context initialisation.
*
* This function initialises or resets a context for a new SHA-1
* computation. It also sets the vtable pointer.
*
* \param ctx pointer to the context structure.
*/
void br_sha1_init(br_sha1_context *ctx);
/**
* \brief Inject some data bytes in a running SHA-1 computation.
*
* The provided context is updated with some data bytes. If the number
* of bytes (`len`) is zero, then the data pointer (`data`) is ignored
* and may be `NULL`, and this function does nothing.
*
* \param ctx pointer to the context structure.
* \param data pointer to the injected data.
* \param len injected data length (in bytes).
*/
void br_sha1_update(br_sha1_context *ctx, const void *data, size_t len);
/**
* \brief Compute SHA-1 output.
*
* The SHA-1 output for the concatenation of all bytes injected in the
* provided context since the last initialisation or reset call, is
* computed and written in the buffer pointed to by `out`. The context
* itself is not modified, so extra bytes may be injected afterwards
* to continue that computation.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the hash output.
*/
void br_sha1_out(const br_sha1_context *ctx, void *out);
/**
* \brief Save SHA-1 running state.
*
* The running state for SHA-1 (output of the last internal block
* processing) is written in the buffer pointed to by `out`. The
* number of bytes injected since the last initialisation or reset
* call is returned. The context is not modified.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the running state.
* \return the injected total byte length.
*/
uint64_t br_sha1_state(const br_sha1_context *ctx, void *out);
/**
* \brief Restore SHA-1 running state.
*
* The running state for SHA-1 is set to the provided values.
*
* \param ctx pointer to the context structure.
* \param stb source buffer for the running state.
* \param count the injected total byte length.
*/
void br_sha1_set_state(br_sha1_context *ctx, const void *stb, uint64_t count);
/**
* \brief Symbolic identifier for SHA-224.
*/
#define br_sha224_ID 3
/**
* \brief SHA-224 output size (in bytes).
*/
#define br_sha224_SIZE 28
/**
* \brief Constant vtable for SHA-224.
*/
extern const br_hash_class br_sha224_vtable;
/**
* \brief SHA-224 context.
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/**
* \brief Pointer to vtable for this context.
*/
const br_hash_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
unsigned char buf[64];
uint64_t count;
uint32_t val[8];
#endif
} br_sha224_context;
/**
* \brief SHA-224 context initialisation.
*
* This function initialises or resets a context for a new SHA-224
* computation. It also sets the vtable pointer.
*
* \param ctx pointer to the context structure.
*/
void br_sha224_init(br_sha224_context *ctx);
/**
* \brief Inject some data bytes in a running SHA-224 computation.
*
* The provided context is updated with some data bytes. If the number
* of bytes (`len`) is zero, then the data pointer (`data`) is ignored
* and may be `NULL`, and this function does nothing.
*
* \param ctx pointer to the context structure.
* \param data pointer to the injected data.
* \param len injected data length (in bytes).
*/
void br_sha224_update(br_sha224_context *ctx, const void *data, size_t len);
/**
* \brief Compute SHA-224 output.
*
* The SHA-224 output for the concatenation of all bytes injected in the
* provided context since the last initialisation or reset call, is
* computed and written in the buffer pointed to by `out`. The context
* itself is not modified, so extra bytes may be injected afterwards
* to continue that computation.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the hash output.
*/
void br_sha224_out(const br_sha224_context *ctx, void *out);
/**
* \brief Save SHA-224 running state.
*
* The running state for SHA-224 (output of the last internal block
* processing) is written in the buffer pointed to by `out`. The
* number of bytes injected since the last initialisation or reset
* call is returned. The context is not modified.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the running state.
* \return the injected total byte length.
*/
uint64_t br_sha224_state(const br_sha224_context *ctx, void *out);
/**
* \brief Restore SHA-224 running state.
*
* The running state for SHA-224 is set to the provided values.
*
* \param ctx pointer to the context structure.
* \param stb source buffer for the running state.
* \param count the injected total byte length.
*/
void br_sha224_set_state(br_sha224_context *ctx,
const void *stb, uint64_t count);
/**
* \brief Symbolic identifier for SHA-256.
*/
#define br_sha256_ID 4
/**
* \brief SHA-256 output size (in bytes).
*/
#define br_sha256_SIZE 32
/**
* \brief Constant vtable for SHA-256.
*/
extern const br_hash_class br_sha256_vtable;
#ifdef BR_DOXYGEN_IGNORE
/**
* \brief SHA-256 context.
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/**
* \brief Pointer to vtable for this context.
*/
const br_hash_class *vtable;
} br_sha256_context;
#else
typedef br_sha224_context br_sha256_context;
#endif
/**
* \brief SHA-256 context initialisation.
*
* This function initialises or resets a context for a new SHA-256
* computation. It also sets the vtable pointer.
*
* \param ctx pointer to the context structure.
*/
void br_sha256_init(br_sha256_context *ctx);
#ifdef BR_DOXYGEN_IGNORE
/**
* \brief Inject some data bytes in a running SHA-256 computation.
*
* The provided context is updated with some data bytes. If the number
* of bytes (`len`) is zero, then the data pointer (`data`) is ignored
* and may be `NULL`, and this function does nothing.
*
* \param ctx pointer to the context structure.
* \param data pointer to the injected data.
* \param len injected data length (in bytes).
*/
void br_sha256_update(br_sha256_context *ctx, const void *data, size_t len);
#else
#define br_sha256_update br_sha224_update
#endif
/**
* \brief Compute SHA-256 output.
*
* The SHA-256 output for the concatenation of all bytes injected in the
* provided context since the last initialisation or reset call, is
* computed and written in the buffer pointed to by `out`. The context
* itself is not modified, so extra bytes may be injected afterwards
* to continue that computation.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the hash output.
*/
void br_sha256_out(const br_sha256_context *ctx, void *out);
#if BR_DOXYGEN_IGNORE
/**
* \brief Save SHA-256 running state.
*
* The running state for SHA-256 (output of the last internal block
* processing) is written in the buffer pointed to by `out`. The
* number of bytes injected since the last initialisation or reset
* call is returned. The context is not modified.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the running state.
* \return the injected total byte length.
*/
uint64_t br_sha256_state(const br_sha256_context *ctx, void *out);
#else
#define br_sha256_state br_sha224_state
#endif
#if BR_DOXYGEN_IGNORE
/**
* \brief Restore SHA-256 running state.
*
* The running state for SHA-256 is set to the provided values.
*
* \param ctx pointer to the context structure.
* \param stb source buffer for the running state.
* \param count the injected total byte length.
*/
void br_sha256_set_state(br_sha256_context *ctx,
const void *stb, uint64_t count);
#else
#define br_sha256_set_state br_sha224_set_state
#endif
/**
* \brief Symbolic identifier for SHA-384.
*/
#define br_sha384_ID 5
/**
* \brief SHA-384 output size (in bytes).
*/
#define br_sha384_SIZE 48
/**
* \brief Constant vtable for SHA-384.
*/
extern const br_hash_class br_sha384_vtable;
/**
* \brief SHA-384 context.
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/**
* \brief Pointer to vtable for this context.
*/
const br_hash_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
unsigned char buf[128];
uint64_t count;
uint64_t val[8];
#endif
} br_sha384_context;
/**
* \brief SHA-384 context initialisation.
*
* This function initialises or resets a context for a new SHA-384
* computation. It also sets the vtable pointer.
*
* \param ctx pointer to the context structure.
*/
void br_sha384_init(br_sha384_context *ctx);
/**
* \brief Inject some data bytes in a running SHA-384 computation.
*
* The provided context is updated with some data bytes. If the number
* of bytes (`len`) is zero, then the data pointer (`data`) is ignored
* and may be `NULL`, and this function does nothing.
*
* \param ctx pointer to the context structure.
* \param data pointer to the injected data.
* \param len injected data length (in bytes).
*/
void br_sha384_update(br_sha384_context *ctx, const void *data, size_t len);
/**
* \brief Compute SHA-384 output.
*
* The SHA-384 output for the concatenation of all bytes injected in the
* provided context since the last initialisation or reset call, is
* computed and written in the buffer pointed to by `out`. The context
* itself is not modified, so extra bytes may be injected afterwards
* to continue that computation.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the hash output.
*/
void br_sha384_out(const br_sha384_context *ctx, void *out);
/**
* \brief Save SHA-384 running state.
*
* The running state for SHA-384 (output of the last internal block
* processing) is written in the buffer pointed to by `out`. The
* number of bytes injected since the last initialisation or reset
* call is returned. The context is not modified.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the running state.
* \return the injected total byte length.
*/
uint64_t br_sha384_state(const br_sha384_context *ctx, void *out);
/**
* \brief Restore SHA-384 running state.
*
* The running state for SHA-384 is set to the provided values.
*
* \param ctx pointer to the context structure.
* \param stb source buffer for the running state.
* \param count the injected total byte length.
*/
void br_sha384_set_state(br_sha384_context *ctx,
const void *stb, uint64_t count);
/**
* \brief Symbolic identifier for SHA-512.
*/
#define br_sha512_ID 6
/**
* \brief SHA-512 output size (in bytes).
*/
#define br_sha512_SIZE 64
/**
* \brief Constant vtable for SHA-512.
*/
extern const br_hash_class br_sha512_vtable;
#ifdef BR_DOXYGEN_IGNORE
/**
* \brief SHA-512 context.
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/**
* \brief Pointer to vtable for this context.
*/
const br_hash_class *vtable;
} br_sha512_context;
#else
typedef br_sha384_context br_sha512_context;
#endif
/**
* \brief SHA-512 context initialisation.
*
* This function initialises or resets a context for a new SHA-512
* computation. It also sets the vtable pointer.
*
* \param ctx pointer to the context structure.
*/
void br_sha512_init(br_sha512_context *ctx);
#ifdef BR_DOXYGEN_IGNORE
/**
* \brief Inject some data bytes in a running SHA-512 computation.
*
* The provided context is updated with some data bytes. If the number
* of bytes (`len`) is zero, then the data pointer (`data`) is ignored
* and may be `NULL`, and this function does nothing.
*
* \param ctx pointer to the context structure.
* \param data pointer to the injected data.
* \param len injected data length (in bytes).
*/
void br_sha512_update(br_sha512_context *ctx, const void *data, size_t len);
#else
#define br_sha512_update br_sha384_update
#endif
/**
* \brief Compute SHA-512 output.
*
* The SHA-512 output for the concatenation of all bytes injected in the
* provided context since the last initialisation or reset call, is
* computed and written in the buffer pointed to by `out`. The context
* itself is not modified, so extra bytes may be injected afterwards
* to continue that computation.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the hash output.
*/
void br_sha512_out(const br_sha512_context *ctx, void *out);
#ifdef BR_DOXYGEN_IGNORE
/**
* \brief Save SHA-512 running state.
*
* The running state for SHA-512 (output of the last internal block
* processing) is written in the buffer pointed to by `out`. The
* number of bytes injected since the last initialisation or reset
* call is returned. The context is not modified.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the running state.
* \return the injected total byte length.
*/
uint64_t br_sha512_state(const br_sha512_context *ctx, void *out);
#else
#define br_sha512_state br_sha384_state
#endif
#ifdef BR_DOXYGEN_IGNORE
/**
* \brief Restore SHA-512 running state.
*
* The running state for SHA-512 is set to the provided values.
*
* \param ctx pointer to the context structure.
* \param stb source buffer for the running state.
* \param count the injected total byte length.
*/
void br_sha512_set_state(br_sha512_context *ctx,
const void *stb, uint64_t count);
#else
#define br_sha512_set_state br_sha384_set_state
#endif
/*
* "md5sha1" is a special hash function that computes both MD5 and SHA-1
* on the same input, and produces a 36-byte output (MD5 and SHA-1
* concatenation, in that order). State size is also 36 bytes.
*/
/**
* \brief Symbolic identifier for MD5+SHA-1.
*
* MD5+SHA-1 is the concatenation of MD5 and SHA-1, computed over the
* same input. It is not one of the functions identified in TLS, so
* we give it a symbolic identifier of value 0.
*/
#define br_md5sha1_ID 0
/**
* \brief MD5+SHA-1 output size (in bytes).
*/
#define br_md5sha1_SIZE 36
/**
* \brief Constant vtable for MD5+SHA-1.
*/
extern const br_hash_class br_md5sha1_vtable;
/**
* \brief MD5+SHA-1 context.
*
* First field is a pointer to the vtable; it is set by the initialisation
* function. Other fields are not supposed to be accessed by user code.
*/
typedef struct {
/**
* \brief Pointer to vtable for this context.
*/
const br_hash_class *vtable;
#ifndef BR_DOXYGEN_IGNORE
unsigned char buf[64];
uint64_t count;
uint32_t val_md5[4];
uint32_t val_sha1[5];
#endif
} br_md5sha1_context;
/**
* \brief MD5+SHA-1 context initialisation.
*
* This function initialises or resets a context for a new SHA-512
* computation. It also sets the vtable pointer.
*
* \param ctx pointer to the context structure.
*/
void br_md5sha1_init(br_md5sha1_context *ctx);
/**
* \brief Inject some data bytes in a running MD5+SHA-1 computation.
*
* The provided context is updated with some data bytes. If the number
* of bytes (`len`) is zero, then the data pointer (`data`) is ignored
* and may be `NULL`, and this function does nothing.
*
* \param ctx pointer to the context structure.
* \param data pointer to the injected data.
* \param len injected data length (in bytes).
*/
void br_md5sha1_update(br_md5sha1_context *ctx, const void *data, size_t len);
/**
* \brief Compute MD5+SHA-1 output.
*
* The MD5+SHA-1 output for the concatenation of all bytes injected in the
* provided context since the last initialisation or reset call, is
* computed and written in the buffer pointed to by `out`. The context
* itself is not modified, so extra bytes may be injected afterwards
* to continue that computation.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the hash output.
*/
void br_md5sha1_out(const br_md5sha1_context *ctx, void *out);
/**
* \brief Save MD5+SHA-1 running state.
*
* The running state for MD5+SHA-1 (output of the last internal block
* processing) is written in the buffer pointed to by `out`. The
* number of bytes injected since the last initialisation or reset
* call is returned. The context is not modified.
*
* \param ctx pointer to the context structure.
* \param out destination buffer for the running state.
* \return the injected total byte length.
*/
uint64_t br_md5sha1_state(const br_md5sha1_context *ctx, void *out);
/**
* \brief Restore MD5+SHA-1 running state.
*
* The running state for MD5+SHA-1 is set to the provided values.
*
* \param ctx pointer to the context structure.
* \param stb source buffer for the running state.
* \param count the injected total byte length.
*/
void br_md5sha1_set_state(br_md5sha1_context *ctx,
const void *stb, uint64_t count);
/**
* \brief Aggregate context for configurable hash function support.
*
* The `br_hash_compat_context` type is a type which is large enough to
* serve as context for all standard hash functions defined above.
*/
typedef union {
const br_hash_class *vtable;
br_md5_context md5;
br_sha1_context sha1;
br_sha224_context sha224;
br_sha256_context sha256;
br_sha384_context sha384;
br_sha512_context sha512;
br_md5sha1_context md5sha1;
} br_hash_compat_context;
/*
* The multi-hasher is a construct that handles hashing of the same input
* data with several hash functions, with a single shared input buffer.
* It can handle MD5, SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512
* simultaneously, though which functions are activated depends on
* the set implementation pointers.
*/
/**
* \brief Multi-hasher context structure.
*
* The multi-hasher runs up to six hash functions in the standard TLS list
* (MD5, SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512) in parallel, over
* the same input.
*
* The multi-hasher does _not_ follow the OOP structure with a vtable.
* Instead, it is configured with the vtables of the hash functions it
* should run. Structure fields are not supposed to be accessed directly.
*/
typedef struct {
#ifndef BR_DOXYGEN_IGNORE
unsigned char buf[128];
uint64_t count;
uint32_t val_32[25];
uint64_t val_64[16];
const br_hash_class *impl[6];
#endif
} br_multihash_context;
/**
* \brief Clear a multi-hasher context.
*
* This should always be called once on a given context, _before_ setting
* the implementation pointers.
*
* \param ctx the multi-hasher context.
*/
void br_multihash_zero(br_multihash_context *ctx);
/**
* \brief Set a hash function implementation.
*
* Implementations shall be set _after_ clearing the context (with
* `br_multihash_zero()`) but _before_ initialising the computation
* (with `br_multihash_init()`). The hash function implementation
* MUST be one of the standard hash functions (MD5, SHA-1, SHA-224,
* SHA-256, SHA-384 or SHA-512); it may also be `NULL` to remove
* an implementation from the multi-hasher.
*
* \param ctx the multi-hasher context.
* \param id the hash function symbolic identifier.
* \param impl the hash function vtable, or `NULL`.
*/
static inline void
br_multihash_setimpl(br_multihash_context *ctx,
int id, const br_hash_class *impl)
{
/*
* This code relies on hash functions ID being values 1 to 6,
* in the MD5 to SHA-512 order.
*/
ctx->impl[id - 1] = impl;
}
/**
* \brief Get a hash function implementation.
*
* This function returns the currently configured vtable for a given
* hash function (by symbolic ID). If no such function was configured in
* the provided multi-hasher context, then this function returns `NULL`.
*
* \param ctx the multi-hasher context.
* \param id the hash function symbolic identifier.
* \return the hash function vtable, or `NULL`.
*/
static inline const br_hash_class *
br_multihash_getimpl(const br_multihash_context *ctx, int id)
{
return ctx->impl[id - 1];
}
/**
* \brief Reset a multi-hasher context.
*
* This function prepares the context for a new hashing computation,
* for all implementations configured at that point.
*
* \param ctx the multi-hasher context.
*/
void br_multihash_init(br_multihash_context *ctx);
/**
* \brief Inject some data bytes in a running multi-hashing computation.
*
* The provided context is updated with some data bytes. If the number
* of bytes (`len`) is zero, then the data pointer (`data`) is ignored
* and may be `NULL`, and this function does nothing.
*
* \param ctx pointer to the context structure.
* \param data pointer to the injected data.
* \param len injected data length (in bytes).
*/
void br_multihash_update(br_multihash_context *ctx,
const void *data, size_t len);
/**
* \brief Compute a hash output from a multi-hasher.
*
* The hash output for the concatenation of all bytes injected in the
* provided context since the last initialisation or reset call, is
* computed and written in the buffer pointed to by `dst`. The hash
* function to use is identified by `id` and must be one of the standard
* hash functions. If that hash function was indeed configured in the
* multi-hasher context, the corresponding hash value is written in
* `dst` and its length (in bytes) is returned. If the hash function
* was _not_ configured, then nothing is written in `dst` and 0 is
* returned.
*
* The context itself is not modified, so extra bytes may be injected
* afterwards to continue the hash computations.
*
* \param ctx pointer to the context structure.
* \param id the hash function symbolic identifier.
* \param dst destination buffer for the hash output.
* \return the hash output length (in bytes), or 0.
*/
size_t br_multihash_out(const br_multihash_context *ctx, int id, void *dst);
/**
* \brief Type for a GHASH implementation.
*
* GHASH is a sort of keyed hash meant to be used to implement GCM in
* combination with a block cipher (with 16-byte blocks).
*
* The `y` array has length 16 bytes and is used for input and output; in
* a complete GHASH run, it starts with an all-zero value. `h` is a 16-byte
* value that serves as key (it is derived from the encryption key in GCM,
* using the block cipher). The data length (`len`) is expressed in bytes.
* The `y` array is updated.
*
* If the data length is not a multiple of 16, then the data is implicitly
* padded with zeros up to the next multiple of 16. Thus, when using GHASH
* in GCM, this method may be called twice, for the associated data and
* for the ciphertext, respectively; the zero-padding implements exactly
* the GCM rules.
*
* \param y the array to update.
* \param h the GHASH key.
* \param data the input data (may be `NULL` if `len` is zero).
* \param len the input data length (in bytes).
*/
typedef void (*br_ghash)(void *y, const void *h, const void *data, size_t len);
/**
* \brief GHASH implementation using multiplications (mixed 32-bit).
*
* This implementation uses multiplications of 32-bit values, with a
* 64-bit result. It is constant-time (if multiplications are
* constant-time).
*
* \param y the array to update.
* \param h the GHASH key.
* \param data the input data (may be `NULL` if `len` is zero).
* \param len the input data length (in bytes).
*/
void br_ghash_ctmul(void *y, const void *h, const void *data, size_t len);
/**
* \brief GHASH implementation using multiplications (strict 32-bit).
*
* This implementation uses multiplications of 32-bit values, with a
* 32-bit result. It is usually somewhat slower than `br_ghash_ctmul()`,
* but it is expected to be faster on architectures for which the
* 32-bit multiplication opcode does not yield the upper 32 bits of the
* product. It is constant-time (if multiplications are constant-time).
*
* \param y the array to update.
* \param h the GHASH key.
* \param data the input data (may be `NULL` if `len` is zero).
* \param len the input data length (in bytes).
*/
void br_ghash_ctmul32(void *y, const void *h, const void *data, size_t len);
/**
* \brief GHASH implementation using multiplications (64-bit).
*
* This implementation uses multiplications of 64-bit values, with a
* 64-bit result. It is constant-time (if multiplications are
* constant-time). It is substantially faster than `br_ghash_ctmul()`
* and `br_ghash_ctmul32()` on most 64-bit architectures.
*
* \param y the array to update.
* \param h the GHASH key.
* \param data the input data (may be `NULL` if `len` is zero).
* \param len the input data length (in bytes).
*/
void br_ghash_ctmul64(void *y, const void *h, const void *data, size_t len);
/**
* \brief GHASH implementation using the `pclmulqdq` opcode (part of the
* AES-NI instructions).
*
* This implementation is available only on x86 platforms where the
* compiler supports the relevant intrinsic functions. Even if the
* compiler supports these functions, the local CPU might not support
* the `pclmulqdq` opcode, meaning that a call will fail with an
* illegal instruction exception. To safely obtain a pointer to this
* function when supported (or 0 otherwise), use `br_ghash_pclmul_get()`.
*
* \param y the array to update.
* \param h the GHASH key.
* \param data the input data (may be `NULL` if `len` is zero).
* \param len the input data length (in bytes).
*/
void br_ghash_pclmul(void *y, const void *h, const void *data, size_t len);
/**
* \brief Obtain the `pclmul` GHASH implementation, if available.
*
* If the `pclmul` implementation was compiled in the library (depending
* on the compiler abilities) _and_ the local CPU appears to support the
* opcode, then this function will return a pointer to the
* `br_ghash_pclmul()` function. Otherwise, it will return `0`.
*
* \return the `pclmul` GHASH implementation, or `0`.
*/
br_ghash br_ghash_pclmul_get(void);
/**
* \brief GHASH implementation using the POWER8 opcodes.
*
* This implementation is available only on POWER8 platforms (and later).
* To safely obtain a pointer to this function when supported (or 0
* otherwise), use `br_ghash_pwr8_get()`.
*
* \param y the array to update.
* \param h the GHASH key.
* \param data the input data (may be `NULL` if `len` is zero).
* \param len the input data length (in bytes).
*/
void br_ghash_pwr8(void *y, const void *h, const void *data, size_t len);
/**
* \brief Obtain the `pwr8` GHASH implementation, if available.
*
* If the `pwr8` implementation was compiled in the library (depending
* on the compiler abilities) _and_ the local CPU appears to support the
* opcode, then this function will return a pointer to the
* `br_ghash_pwr8()` function. Otherwise, it will return `0`.
*
* \return the `pwr8` GHASH implementation, or `0`.
*/
br_ghash br_ghash_pwr8_get(void);
#ifdef __cplusplus
}
#endif
#endif