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cosmopolitan/third_party/mbedtls/hmac_drbg.c
Justine Tunney 957c61cbbf
Release Cosmopolitan v3.3 
This change upgrades to GCC 12.3 and GNU binutils 2.42. The GNU linker
appears to have changed things so that only a single de-duplicated str
table is present in the binary, and it gets placed wherever the linker
wants, regardless of what the linker script says. To cope with that we
need to stop using .ident to embed licenses. As such, this change does
significant work to revamp how third party licenses are defined in the
codebase, using `.section .notice,"aR",@progbits`.

This new GCC 12.3 toolchain has support for GNU indirect functions. It
lets us support __target_clones__ for the first time. This is used for
optimizing the performance of libc string functions such as strlen and
friends so far on x86, by ensuring AVX systems favor a second codepath
that uses VEX encoding. It shaves some latency off certain operations.
It's a useful feature to have for scientific computing for the reasons
explained by the test/libcxx/openmp_test.cc example which compiles for
fifteen different microarchitectures. Thanks to the upgrades, it's now
also possible to use newer instruction sets, such as AVX512FP16, VNNI.

Cosmo now uses the %gs register on x86 by default for TLS. Doing it is
helpful for any program that links `cosmo_dlopen()`. Such programs had
to recompile their binaries at startup to change the TLS instructions.
That's not great, since it means every page in the executable needs to
be faulted. The work of rewriting TLS-related x86 opcodes, is moved to
fixupobj.com instead. This is great news for MacOS x86 users, since we
previously needed to morph the binary every time for that platform but
now that's no longer necessary. The only platforms where we need fixup
of TLS x86 opcodes at runtime are now Windows, OpenBSD, and NetBSD. On
Windows we morph TLS to point deeper into the TIB, based on a TlsAlloc
assignment, and on OpenBSD/NetBSD we morph %gs back into %fs since the
kernels do not allow us to specify a value for the %gs register.

OpenBSD users are now required to use APE Loader to run Cosmo binaries
and assimilation is no longer possible. OpenBSD kernel needs to change
to allow programs to specify a value for the %gs register, or it needs
to stop marking executable pages loaded by the kernel as mimmutable().

This release fixes __constructor__, .ctor, .init_array, and lastly the
.preinit_array so they behave the exact same way as glibc.

We no longer use hex constants to define math.h symbols like M_PI.
2024-02-20 13:27:59 -08:00

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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright The Mbed TLS Contributors │
│ │
│ 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 │
│ │
│ http://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. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "third_party/mbedtls/common.h"
#include "third_party/mbedtls/error.h"
#include "third_party/mbedtls/hmac_drbg.h"
#include "third_party/mbedtls/platform.h"
__static_yoink("mbedtls_notice");
/*
* HMAC_DRBG implementation (NIST SP 800-90)
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* 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
*
* http://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.
*/
/*
* The NIST SP 800-90A DRBGs are described in the following publication.
* http://csrc.nist.gov/publications/nistpubs/800-90A/SP800-90A.pdf
* References below are based on rev. 1 (January 2012).
*/
#if defined(MBEDTLS_HMAC_DRBG_C)
/**
* \brief HMAC_DRBG context initialization.
*
* This function makes the context ready for mbedtls_hmac_drbg_seed(),
* mbedtls_hmac_drbg_seed_buf() or mbedtls_hmac_drbg_free().
*
* \note The reseed interval is #MBEDTLS_HMAC_DRBG_RESEED_INTERVAL
* by default. Override this value by calling
* mbedtls_hmac_drbg_set_reseed_interval().
*
* \param ctx HMAC_DRBG context to be initialized.
*/
void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx )
{
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_hmac_drbg_context ) );
ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
}
/**
* \brief This function updates the state of the HMAC_DRBG context.
*
* \note This function is not thread-safe. It is not safe
* to call this function if another thread might be
* concurrently obtaining random numbers from the same
* context or updating or reseeding the same context.
*
* \param ctx The HMAC_DRBG context.
* \param additional The data to update the state with.
* If this is \c NULL, there is no additional data.
* \param add_len Length of \p additional in bytes.
* Unused if \p additional is \c NULL.
*
* \return \c 0 on success, or an error from the underlying
* hash calculation.
*/
int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,
const unsigned char *additional,
size_t add_len )
{
size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
unsigned char rounds = ( additional != NULL && add_len != 0 ) ? 2 : 1;
unsigned char sep[1];
unsigned char K[MBEDTLS_MD_MAX_SIZE];
int ret = MBEDTLS_ERR_MD_BAD_INPUT_DATA;
for( sep[0] = 0; sep[0] < rounds; sep[0]++ )
{
/* Step 1 or 4 */
if( ( ret = mbedtls_md_hmac_reset( &ctx->md_ctx ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
ctx->V, md_len ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
sep, 1 ) ) != 0 )
goto exit;
if( rounds == 2 )
{
if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
additional, add_len ) ) != 0 )
goto exit;
}
if( ( ret = mbedtls_md_hmac_finish( &ctx->md_ctx, K ) ) != 0 )
goto exit;
/* Step 2 or 5 */
if( ( ret = mbedtls_md_hmac_starts( &ctx->md_ctx, K, md_len ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
ctx->V, md_len ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V ) ) != 0 )
goto exit;
}
exit:
mbedtls_platform_zeroize( K, sizeof( K ) );
return( ret );
}
/**
* \brief Initilisation of simpified HMAC_DRBG (never reseeds).
*
* This function is meant for use in algorithms that need a pseudorandom
* input such as deterministic ECDSA.
*
* \param ctx HMAC_DRBG context to be initialised.
* \param md_info MD algorithm to use for HMAC_DRBG.
* \param data Concatenation of the initial entropy string and
* the additional data.
* \param data_len Length of \p data in bytes.
*
* \return \c 0 if successful. or
* \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
* invalid.
* \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
* memory to allocate context data.
*/
int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
const mbedtls_md_info_t * md_info,
const unsigned char *data, size_t data_len )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
return( ret );
/*
* Set initial working state.
* Use the V memory location, which is currently all 0, to initialize the
* MD context with an all-zero key. Then set V to its initial value.
*/
if( ( ret = mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V,
mbedtls_md_get_size( md_info ) ) ) != 0 )
return( ret );
memset( ctx->V, 0x01, mbedtls_md_get_size( md_info ) );
if( ( ret = mbedtls_hmac_drbg_update_ret( ctx, data, data_len ) ) != 0 )
return( ret );
return( 0 );
}
/*
* Internal function used both for seeding and reseeding the DRBG.
* Comments starting with arabic numbers refer to section 10.1.2.4
* of SP800-90A, while roman numbers refer to section 9.2.
*/
static int hmac_drbg_reseed_core( mbedtls_hmac_drbg_context *ctx,
const unsigned char *additional, size_t len,
int use_nonce )
{
unsigned char seed[MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT];
size_t seedlen = 0;
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
{
size_t total_entropy_len;
if( use_nonce == 0 )
total_entropy_len = ctx->entropy_len;
else
total_entropy_len = ctx->entropy_len * 3 / 2;
/* III. Check input length */
if( len > MBEDTLS_HMAC_DRBG_MAX_INPUT ||
total_entropy_len + len > MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT )
{
return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
}
}
mbedtls_platform_zeroize( seed, MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT );
/* IV. Gather entropy_len bytes of entropy for the seed */
if( ( ret = ctx->f_entropy( ctx->p_entropy,
seed, ctx->entropy_len ) ) != 0 )
{
return( MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED );
}
seedlen += ctx->entropy_len;
/* For initial seeding, allow adding of nonce generated
* from the entropy source. See Sect 8.6.7 in SP800-90A. */
if( use_nonce )
{
/* Note: We don't merge the two calls to f_entropy() in order
* to avoid requesting too much entropy from f_entropy()
* at once. Specifically, if the underlying digest is not
* SHA-1, 3 / 2 * entropy_len is at least 36 Bytes, which
* is larger than the maximum of 32 Bytes that our own
* entropy source implementation can emit in a single
* call in configurations disabling SHA-512. */
if( ( ret = ctx->f_entropy( ctx->p_entropy,
seed + seedlen,
ctx->entropy_len / 2 ) ) != 0 )
{
return( MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED );
}
seedlen += ctx->entropy_len / 2;
}
/* 1. Concatenate entropy and additional data if any */
if( additional != NULL && len != 0 )
{
memcpy( seed + seedlen, additional, len );
seedlen += len;
}
/* 2. Update state */
if( ( ret = mbedtls_hmac_drbg_update_ret( ctx, seed, seedlen ) ) != 0 )
goto exit;
/* 3. Reset reseed_counter */
ctx->reseed_counter = 1;
exit:
/* 4. Done */
mbedtls_platform_zeroize( seed, seedlen );
return( ret );
}
/**
* \brief This function reseeds the HMAC_DRBG context, that is
* extracts data from the entropy source.
*
* \note This function is not thread-safe. It is not safe
* to call this function if another thread might be
* concurrently obtaining random numbers from the same
* context or updating or reseeding the same context.
*
* \param ctx The HMAC_DRBG context.
* \param additional Additional data to add to the state.
* If this is \c NULL, there is no additional data
* and \p len should be \c 0.
* \param len The length of the additional data.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
* and also at most
* #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len
* where \p entropy_len is the entropy length
* (see mbedtls_hmac_drbg_set_entropy_len()).
*
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* if a call to the entropy function failed.
*/
int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
const unsigned char *additional, size_t len )
{
return( hmac_drbg_reseed_core( ctx, additional, len, 0 ) );
}
/**
* \brief HMAC_DRBG initial seeding.
*
* Set the initial seed and set up the entropy source for future reseeds.
*
* A typical choice for the \p f_entropy and \p p_entropy parameters is
* to use the entropy module:
* - \p f_entropy is mbedtls_entropy_func();
* - \p p_entropy is an instance of ::mbedtls_entropy_context initialized
* with mbedtls_entropy_init() (which registers the platform's default
* entropy sources).
*
* You can provide a personalization string in addition to the
* entropy source, to make this instantiation as unique as possible.
*
* \note By default, the security strength as defined by NIST is:
* - 128 bits if \p md_info is SHA-1;
* - 192 bits if \p md_info is SHA-224;
* - 256 bits if \p md_info is SHA-256, SHA-384 or SHA-512.
* Note that SHA-256 is just as efficient as SHA-224.
* The security strength can be reduced if a smaller
* entropy length is set with
* mbedtls_hmac_drbg_set_entropy_len().
*
* \note The default entropy length is the security strength
* (converted from bits to bytes). You can override
* it by calling mbedtls_hmac_drbg_set_entropy_len().
*
* \note During the initial seeding, this function calls
* the entropy source to obtain a nonce
* whose length is half the entropy length.
*
* \param ctx HMAC_DRBG context to be seeded.
* \param md_info MD algorithm to use for HMAC_DRBG.
* \param f_entropy The entropy callback, taking as arguments the
* \p p_entropy context, the buffer to fill, and the
* length of the buffer.
* \p f_entropy is always called with a length that is
* less than or equal to the entropy length.
* \param p_entropy The entropy context to pass to \p f_entropy.
* \param custom The personalization string.
* This can be \c NULL, in which case the personalization
* string is empty regardless of the value of \p len.
* \param len The length of the personalization string.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT
* and also at most
* #MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT - \p entropy_len * 3 / 2
* where \p entropy_len is the entropy length
* described above.
*
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info is
* invalid.
* \return #MBEDTLS_ERR_MD_ALLOC_FAILED if there was not enough
* memory to allocate context data.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* if the call to \p f_entropy failed.
*/
int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
const mbedtls_md_info_t * md_info,
int (*f_entropy)(void *, unsigned char *, size_t),
void *p_entropy,
const unsigned char *custom,
size_t len )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
size_t md_size;
if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
return( ret );
md_size = mbedtls_md_get_size( md_info );
/*
* Set initial working state.
* Use the V memory location, which is currently all 0, to initialize the
* MD context with an all-zero key. Then set V to its initial value.
*/
if( ( ret = mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, md_size ) ) != 0 )
return( ret );
memset( ctx->V, 0x01, md_size );
ctx->f_entropy = f_entropy;
ctx->p_entropy = p_entropy;
if( ctx->entropy_len == 0 )
{
/*
* See SP800-57 5.6.1 (p. 65-66) for the security strength provided by
* each hash function, then according to SP800-90A rev1 10.1 table 2,
* min_entropy_len (in bits) is security_strength.
*
* (This also matches the sizes used in the NIST test vectors.)
*/
ctx->entropy_len = md_size <= 20 ? 16 : /* 160-bits hash -> 128 bits */
md_size <= 28 ? 24 : /* 224-bits hash -> 192 bits */
32; /* better (256+) -> 256 bits */
}
if( ( ret = hmac_drbg_reseed_core( ctx, custom, len,
1 /* add nonce */ ) ) != 0 )
{
return( ret );
}
return( 0 );
}
/**
* \brief This function turns prediction resistance on or off.
* The default value is off.
*
* \note If enabled, entropy is gathered at the beginning of
* every call to mbedtls_hmac_drbg_random_with_add()
* or mbedtls_hmac_drbg_random().
* Only use this if your entropy source has sufficient
* throughput.
*
* \param ctx The HMAC_DRBG context.
* \param resistance #MBEDTLS_HMAC_DRBG_PR_ON or #MBEDTLS_HMAC_DRBG_PR_OFF.
*/
void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
int resistance )
{
ctx->prediction_resistance = resistance;
}
/**
* \brief This function sets the amount of entropy grabbed on each
* seed or reseed.
*
* See the documentation of mbedtls_hmac_drbg_seed() for the default value.
*
* \param ctx The HMAC_DRBG context.
* \param len The amount of entropy to grab, in bytes.
*/
void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx, size_t len )
{
ctx->entropy_len = len;
}
/**
* \brief Set the reseed interval.
*
* The reseed interval is the number of calls to mbedtls_hmac_drbg_random()
* or mbedtls_hmac_drbg_random_with_add() after which the entropy function
* is called again.
*
* The default value is #MBEDTLS_HMAC_DRBG_RESEED_INTERVAL.
*
* \param ctx The HMAC_DRBG context.
* \param interval The reseed interval.
*/
void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx, int interval )
{
ctx->reseed_interval = interval;
}
/**
* \brief This function updates an HMAC_DRBG instance with additional
* data and uses it to generate random data.
*
* This function automatically reseeds if the reseed counter is exceeded
* or prediction resistance is enabled.
*
* \note This function is not thread-safe. It is not safe
* to call this function if another thread might be
* concurrently obtaining random numbers from the same
* context or updating or reseeding the same context.
*
* \param p_rng The HMAC_DRBG context. This must be a pointer to a
* #mbedtls_hmac_drbg_context structure.
* \param output The buffer to fill.
* \param output_len The length of the buffer in bytes.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
* \param additional Additional data to update with.
* If this is \c NULL, there is no additional data
* and \p add_len should be \c 0.
* \param add_len The length of the additional data.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_INPUT.
*
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* if a call to the entropy source failed.
* \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
* \p output_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
* \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if
* \p add_len > #MBEDTLS_HMAC_DRBG_MAX_INPUT.
*/
int mbedtls_hmac_drbg_random_with_add( void *p_rng,
unsigned char *output, size_t out_len,
const unsigned char *additional, size_t add_len )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
size_t left = out_len;
unsigned char *out = output;
/* II. Check request length */
if( out_len > MBEDTLS_HMAC_DRBG_MAX_REQUEST )
return( MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG );
/* III. Check input length */
if( add_len > MBEDTLS_HMAC_DRBG_MAX_INPUT )
return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
/* 1. (aka VII and IX) Check reseed counter and PR */
if( ctx->f_entropy != NULL && /* For no-reseeding instances */
( ctx->prediction_resistance == MBEDTLS_HMAC_DRBG_PR_ON ||
ctx->reseed_counter > ctx->reseed_interval ) )
{
if( ( ret = mbedtls_hmac_drbg_reseed( ctx, additional, add_len ) ) != 0 )
return( ret );
add_len = 0; /* VII.4 */
}
/* 2. Use additional data if any */
if( additional != NULL && add_len != 0 )
{
if( ( ret = mbedtls_hmac_drbg_update_ret( ctx,
additional, add_len ) ) != 0 )
goto exit;
}
/* 3, 4, 5. Generate bytes */
while( left != 0 )
{
size_t use_len = left > md_len ? md_len : left;
if( ( ret = mbedtls_md_hmac_reset( &ctx->md_ctx ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
ctx->V, md_len ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V ) ) != 0 )
goto exit;
memcpy( out, ctx->V, use_len );
out += use_len;
left -= use_len;
}
/* 6. Update */
if( ( ret = mbedtls_hmac_drbg_update_ret( ctx,
additional, add_len ) ) != 0 )
goto exit;
/* 7. Update reseed counter */
ctx->reseed_counter++;
exit:
/* 8. Done */
return( ret );
}
/**
* \brief This function uses HMAC_DRBG to generate random data.
*
* This function automatically reseeds if the reseed counter is exceeded
* or prediction resistance is enabled.
*
* \param p_rng The HMAC_DRBG context. This must be a pointer to a
* #mbedtls_hmac_drbg_context structure.
* \param output The buffer to fill.
* \param out_len The length of the buffer in bytes.
* This must be at most #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
*
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED
* if a call to the entropy source failed.
* \return #MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG if
* \p out_len > #MBEDTLS_HMAC_DRBG_MAX_REQUEST.
*/
int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len )
{
mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
return mbedtls_hmac_drbg_random_with_add( ctx, output, out_len, NULL, 0 );
}
/**
* \brief This function resets HMAC_DRBG context to the state immediately
* after initial call of mbedtls_hmac_drbg_init().
*
* \param ctx The HMAC_DRBG context to free.
*/
void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx )
{
if( ctx == NULL )
return;
mbedtls_md_free( &ctx->md_ctx );
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_hmac_drbg_context ) );
ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
}
#if defined(MBEDTLS_FS_IO)
/**
* \brief This function writes a seed file.
*
* \param ctx The HMAC_DRBG context.
* \param path The name of the file.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on reseed
* failure.
*/
int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
FILE *f;
unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
if( ( f = fopen( path, "wb" ) ) == NULL )
return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
if( ( ret = mbedtls_hmac_drbg_random( ctx, buf, sizeof( buf ) ) ) != 0 )
goto exit;
if( fwrite( buf, 1, sizeof( buf ), f ) != sizeof( buf ) )
{
ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
goto exit;
}
ret = 0;
exit:
fclose( f );
mbedtls_platform_zeroize( buf, sizeof( buf ) );
return( ret );
}
/**
* \brief This function reads and updates a seed file. The seed
* is added to this instance.
*
* \param ctx The HMAC_DRBG context.
* \param path The name of the file.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR on file error.
* \return #MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED on
* reseed failure.
* \return #MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG if the existing
* seed file is too large.
*/
int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
{
int ret = 0;
FILE *f = NULL;
size_t n;
unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
unsigned char c;
if( ( f = fopen( path, "rb" ) ) == NULL )
return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
n = fread( buf, 1, sizeof( buf ), f );
if( fread( &c, 1, 1, f ) != 0 )
{
ret = MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG;
goto exit;
}
if( n == 0 || ferror( f ) )
{
ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
goto exit;
}
fclose( f );
f = NULL;
ret = mbedtls_hmac_drbg_update_ret( ctx, buf, n );
exit:
mbedtls_platform_zeroize( buf, sizeof( buf ) );
if( f != NULL )
fclose( f );
if( ret != 0 )
return( ret );
return( mbedtls_hmac_drbg_write_seed_file( ctx, path ) );
}
#endif /* MBEDTLS_FS_IO */
#if defined(MBEDTLS_SELF_TEST)
#if defined(MBEDTLS_SHA1_C)
#define OUTPUT_LEN 80
/* From a NIST PR=true test vector */
static const unsigned char entropy_pr[] = {
0xa0, 0xc9, 0xab, 0x58, 0xf1, 0xe2, 0xe5, 0xa4, 0xde, 0x3e, 0xbd, 0x4f,
0xf7, 0x3e, 0x9c, 0x5b, 0x64, 0xef, 0xd8, 0xca, 0x02, 0x8c, 0xf8, 0x11,
0x48, 0xa5, 0x84, 0xfe, 0x69, 0xab, 0x5a, 0xee, 0x42, 0xaa, 0x4d, 0x42,
0x17, 0x60, 0x99, 0xd4, 0x5e, 0x13, 0x97, 0xdc, 0x40, 0x4d, 0x86, 0xa3,
0x7b, 0xf5, 0x59, 0x54, 0x75, 0x69, 0x51, 0xe4 };
static const unsigned char result_pr[OUTPUT_LEN] = {
0x9a, 0x00, 0xa2, 0xd0, 0x0e, 0xd5, 0x9b, 0xfe, 0x31, 0xec, 0xb1, 0x39,
0x9b, 0x60, 0x81, 0x48, 0xd1, 0x96, 0x9d, 0x25, 0x0d, 0x3c, 0x1e, 0x94,
0x10, 0x10, 0x98, 0x12, 0x93, 0x25, 0xca, 0xb8, 0xfc, 0xcc, 0x2d, 0x54,
0x73, 0x19, 0x70, 0xc0, 0x10, 0x7a, 0xa4, 0x89, 0x25, 0x19, 0x95, 0x5e,
0x4b, 0xc6, 0x00, 0x1d, 0x7f, 0x4e, 0x6a, 0x2b, 0xf8, 0xa3, 0x01, 0xab,
0x46, 0x05, 0x5c, 0x09, 0xa6, 0x71, 0x88, 0xf1, 0xa7, 0x40, 0xee, 0xf3,
0xe1, 0x5c, 0x02, 0x9b, 0x44, 0xaf, 0x03, 0x44 };
/* From a NIST PR=false test vector */
static const unsigned char entropy_nopr[] = {
0x79, 0x34, 0x9b, 0xbf, 0x7c, 0xdd, 0xa5, 0x79, 0x95, 0x57, 0x86, 0x66,
0x21, 0xc9, 0x13, 0x83, 0x11, 0x46, 0x73, 0x3a, 0xbf, 0x8c, 0x35, 0xc8,
0xc7, 0x21, 0x5b, 0x5b, 0x96, 0xc4, 0x8e, 0x9b, 0x33, 0x8c, 0x74, 0xe3,
0xe9, 0x9d, 0xfe, 0xdf };
static const unsigned char result_nopr[OUTPUT_LEN] = {
0xc6, 0xa1, 0x6a, 0xb8, 0xd4, 0x20, 0x70, 0x6f, 0x0f, 0x34, 0xab, 0x7f,
0xec, 0x5a, 0xdc, 0xa9, 0xd8, 0xca, 0x3a, 0x13, 0x3e, 0x15, 0x9c, 0xa6,
0xac, 0x43, 0xc6, 0xf8, 0xa2, 0xbe, 0x22, 0x83, 0x4a, 0x4c, 0x0a, 0x0a,
0xff, 0xb1, 0x0d, 0x71, 0x94, 0xf1, 0xc1, 0xa5, 0xcf, 0x73, 0x22, 0xec,
0x1a, 0xe0, 0x96, 0x4e, 0xd4, 0xbf, 0x12, 0x27, 0x46, 0xe0, 0x87, 0xfd,
0xb5, 0xb3, 0xe9, 0x1b, 0x34, 0x93, 0xd5, 0xbb, 0x98, 0xfa, 0xed, 0x49,
0xe8, 0x5f, 0x13, 0x0f, 0xc8, 0xa4, 0x59, 0xb7 };
/* "Entropy" from buffer */
static size_t test_offset;
static int hmac_drbg_self_test_entropy( void *data,
unsigned char *buf, size_t len )
{
const unsigned char *p = data;
memcpy( buf, p + test_offset, len );
test_offset += len;
return( 0 );
}
#define CHK( c ) if( (c) != 0 ) \
{ \
if( verbose != 0 ) \
mbedtls_printf( "failed\n" ); \
return( 1 ); \
}
/**
* \brief The HMAC_DRBG Checkup routine.
*
* \return \c 0 if successful.
* \return \c 1 if the test failed.
*/
int mbedtls_hmac_drbg_self_test( int verbose )
{
mbedtls_hmac_drbg_context ctx;
unsigned char buf[OUTPUT_LEN];
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 );
mbedtls_hmac_drbg_init( &ctx );
/*
* PR = True
*/
if( verbose != 0 )
mbedtls_printf( " HMAC_DRBG (PR = True) : " );
test_offset = 0;
CHK( mbedtls_hmac_drbg_seed( &ctx, md_info,
hmac_drbg_self_test_entropy, (void *) entropy_pr,
NULL, 0 ) );
mbedtls_hmac_drbg_set_prediction_resistance( &ctx, MBEDTLS_HMAC_DRBG_PR_ON );
CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
CHK( timingsafe_bcmp( buf, result_pr, OUTPUT_LEN ) );
mbedtls_hmac_drbg_free( &ctx );
mbedtls_hmac_drbg_free( &ctx );
if( verbose != 0 )
mbedtls_printf( "passed\n" );
/*
* PR = False
*/
if( verbose != 0 )
mbedtls_printf( " HMAC_DRBG (PR = False) : " );
mbedtls_hmac_drbg_init( &ctx );
test_offset = 0;
CHK( mbedtls_hmac_drbg_seed( &ctx, md_info,
hmac_drbg_self_test_entropy, (void *) entropy_nopr,
NULL, 0 ) );
CHK( mbedtls_hmac_drbg_reseed( &ctx, NULL, 0 ) );
CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
CHK( timingsafe_bcmp( buf, result_nopr, OUTPUT_LEN ) );
mbedtls_hmac_drbg_free( &ctx );
mbedtls_hmac_drbg_free( &ctx );
if( verbose != 0 )
mbedtls_printf( "passed\n" );
if( verbose != 0 )
mbedtls_printf( "\n" );
return( 0 );
}
#endif /* MBEDTLS_SHA1_C */
#endif /* MBEDTLS_SELF_TEST */
#endif /* MBEDTLS_HMAC_DRBG_C */
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