diff options
Diffstat (limited to 'qemu/roms/ipxe/src/include/ipxe/entropy.h')
-rw-r--r-- | qemu/roms/ipxe/src/include/ipxe/entropy.h | 225 |
1 files changed, 0 insertions, 225 deletions
diff --git a/qemu/roms/ipxe/src/include/ipxe/entropy.h b/qemu/roms/ipxe/src/include/ipxe/entropy.h deleted file mode 100644 index beeb3abfa..000000000 --- a/qemu/roms/ipxe/src/include/ipxe/entropy.h +++ /dev/null @@ -1,225 +0,0 @@ -#ifndef _IPXE_ENTROPY_H -#define _IPXE_ENTROPY_H - -/** @file - * - * Entropy source - * - */ - -FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); - -#include <stdint.h> -#include <string.h> -#include <assert.h> -#include <ipxe/api.h> -#include <ipxe/hash_df.h> -#include <ipxe/sha256.h> -#include <config/entropy.h> - -/** - * Calculate static inline entropy API function name - * - * @v _prefix Subsystem prefix - * @v _api_func API function - * @ret _subsys_func Subsystem API function - */ -#define ENTROPY_INLINE( _subsys, _api_func ) \ - SINGLE_API_INLINE ( ENTROPY_PREFIX_ ## _subsys, _api_func ) - -/** - * Provide a entropy API implementation - * - * @v _prefix Subsystem prefix - * @v _api_func API function - * @v _func Implementing function - */ -#define PROVIDE_ENTROPY( _subsys, _api_func, _func ) \ - PROVIDE_SINGLE_API ( ENTROPY_PREFIX_ ## _subsys, _api_func, _func ) - -/** - * Provide a static inline entropy API implementation - * - * @v _prefix Subsystem prefix - * @v _api_func API function - */ -#define PROVIDE_ENTROPY_INLINE( _subsys, _api_func ) \ - PROVIDE_SINGLE_API_INLINE ( ENTROPY_PREFIX_ ## _subsys, _api_func ) - -/** A noise sample */ -typedef uint8_t noise_sample_t; - -/** An entropy sample */ -typedef uint8_t entropy_sample_t; - -/* Include all architecture-independent entropy API headers */ -#include <ipxe/null_entropy.h> -#include <ipxe/efi/efi_entropy.h> -#include <ipxe/linux/linux_entropy.h> - -/* Include all architecture-dependent entropy API headers */ -#include <bits/entropy.h> - -/** - * Enable entropy gathering - * - * @ret rc Return status code - */ -int entropy_enable ( void ); - -/** - * Disable entropy gathering - * - */ -void entropy_disable ( void ); - -/** - * min-entropy per sample - * - * @ret min_entropy min-entropy of each sample - * - * min-entropy is defined in ANS X9.82 Part 1-2006 Section 8.3 and in - * NIST SP 800-90 Appendix C.3 as - * - * H_min = -log2 ( p_max ) - * - * where p_max is the probability of the most likely sample value. - * - * This must be a compile-time constant. - */ -double min_entropy_per_sample ( void ); - -/** - * Get noise sample - * - * @ret noise Noise sample - * @ret rc Return status code - * - * This is the GetNoise function defined in ANS X9.82 Part 2 - * (October 2011 Draft) Section 6.5.2. - */ -int get_noise ( noise_sample_t *noise ); - -extern int get_entropy_input_tmp ( unsigned int num_samples, - uint8_t *tmp, size_t tmp_len ); - -/** Use SHA-256 as the underlying hash algorithm for Hash_df - * - * Hash_df using SHA-256 is an Approved algorithm in ANS X9.82. - */ -#define entropy_hash_df_algorithm sha256_algorithm - -/** Underlying hash algorithm output length (in bytes) */ -#define ENTROPY_HASH_DF_OUTLEN_BYTES SHA256_DIGEST_SIZE - -/** - * Obtain entropy input - * - * @v min_entropy_bits Minimum amount of entropy, in bits - * @v data Data buffer - * @v min_len Minimum length of entropy input, in bytes - * @v max_len Maximum length of entropy input, in bytes - * @ret len Length of entropy input, in bytes, or negative error - * - * This is the implementation of the Get_entropy_input function (using - * an entropy source as the source of entropy input and condensing - * each entropy source output after each GetEntropy call) as defined - * in ANS X9.82 Part 4 (April 2011 Draft) Section 13.3.4.2. - * - * To minimise code size, the number of samples required is calculated - * at compilation time. - */ -static inline __attribute__ (( always_inline )) int -get_entropy_input ( unsigned int min_entropy_bits, void *data, size_t min_len, - size_t max_len ) { - size_t tmp_len = ( ( ( min_entropy_bits * 2 ) + 7 ) / 8 ); - uint8_t tmp_buf[ tmp_len ]; - uint8_t *tmp = ( ( tmp_len > max_len ) ? tmp_buf : data ); - double min_samples; - unsigned int num_samples; - unsigned int n; - int rc; - - /* Sanity checks */ - linker_assert ( ( min_entropy_per_sample() <= - ( 8 * sizeof ( noise_sample_t ) ) ), - min_entropy_per_sample_is_impossibly_high ); - linker_assert ( ( min_entropy_bits <= ( 8 * max_len ) ), - entropy_buffer_too_small ); - - /* Round up minimum entropy to an integral number of bytes */ - min_entropy_bits = ( ( min_entropy_bits + 7 ) & ~7 ); - - /* Calculate number of samples required to contain sufficient entropy */ - min_samples = ( ( min_entropy_bits * 1.0 ) / min_entropy_per_sample() ); - - /* Round up to a whole number of samples. We don't have the - * ceil() function available, so do the rounding by hand. - */ - num_samples = min_samples; - if ( num_samples < min_samples ) - num_samples++; - linker_assert ( ( num_samples >= min_samples ), rounding_error ); - - /* Floating-point operations are not allowed in iPXE since we - * never set up a suitable environment. Abort the build - * unless the calculated number of samples is a compile-time - * constant. - */ - linker_assert ( __builtin_constant_p ( num_samples ), - num_samples_not_constant ); - - /* (Unnumbered). The output length of the hash function shall - * meet or exceed the security strength indicated by the - * min_entropy parameter. - */ - linker_assert ( ( ( 8 * ENTROPY_HASH_DF_OUTLEN_BYTES ) >= - min_entropy_bits ), hash_df_algorithm_too_weak ); - - /* 1. If ( min_length > max_length ), then return ( FAILURE, Null ) */ - linker_assert ( ( min_len <= max_len ), min_len_greater_than_max_len ); - - /* 2. n = 2 * min_entropy */ - n = ( 2 * min_entropy_bits ); - - /* 3. entropy_total = 0 - * 4. tmp = a fixed n-bit value, such as 0^n - * 5. While ( entropy_total < min_entropy ) - * 5.1. ( status, entropy_bitstring, assessed_entropy ) - * = GetEntropy() - * 5.2. If status indicates an error, return ( status, Null ) - * 5.3. nonce = MakeNextNonce() - * 5.4. tmp = tmp XOR df ( ( nonce || entropy_bitstring ), n ) - * 5.5. entropy_total = entropy_total + assessed_entropy - * - * (The implementation of these steps is inside the function - * get_entropy_input_tmp().) - */ - linker_assert ( __builtin_constant_p ( tmp_len ), - tmp_len_not_constant ); - linker_assert ( ( n == ( 8 * tmp_len ) ), tmp_len_mismatch ); - if ( ( rc = get_entropy_input_tmp ( num_samples, tmp, tmp_len ) ) != 0 ) - return rc; - - /* 6. If ( n < min_length ), then tmp = tmp || 0^(min_length-n) - * 7. If ( n > max_length ), then tmp = df ( tmp, max_length ) - * 8. Return ( SUCCESS, tmp ) - */ - if ( tmp_len < min_len ) { - /* (Data is already in-place.) */ - linker_assert ( ( data == tmp ), data_not_inplace ); - memset ( ( data + tmp_len ), 0, ( min_len - tmp_len ) ); - return min_len; - } else if ( tmp_len > max_len ) { - linker_assert ( ( tmp == tmp_buf ), data_inplace ); - hash_df ( &entropy_hash_df_algorithm, tmp, tmp_len, - data, max_len ); - return max_len; - } else { - /* (Data is already in-place.) */ - linker_assert ( ( data == tmp ), data_not_inplace ); - return tmp_len; - } -} - -#endif /* _IPXE_ENTROPY_H */ |