xCAT/xNBA
2
0
Fork 0
mirror of https://github.com/xcat2/xNBA.git synced 2025-02-06 22:11:57 +00:00
Code Issues Projects Releases Wiki Activity

[rng] Add ANS X9.82 Approved HMAC_DRBG algorithm

Browse Source 
ANS X9.82 specifies several Approved algorithms for use in a
Deterministic Random Bit Generator (DRBG).  One such algorithm is
HMAC_DRBG, which can be implemented using the existing iPXE SHA-1 and
HMAC functionality.  This algorithm provides a maximum security
strength of 128 bits.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown 2012-01-23 14:52:56 +00:00
parent f5bbe7ec4a
commit 5c2d6fa399
3 changed files with 496 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

342
src/crypto/hmac_drbg.c Normal file
View File

@ -0,0 +1,342 @@
/*
* Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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 any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
/** @file
*
* HMAC_DRBG algorithm
*
* This algorithm is designed to comply with ANS X9.82 Part 3-2007
* Section 10.2.2.2. This standard is not freely available, but most
* of the text appears to be shared with NIST SP 800-90, which can be
* downloaded from
*
* http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
*
* Where possible, references are given to both documents. In the
* case of any disagreement, ANS X9.82 takes priority over NIST SP
* 800-90. (In particular, note that some algorithms that are
* Approved by NIST SP 800-90 are not Approved by ANS X9.82.)
*/
#include <stdint.h>
#include <errno.h>
#include <ipxe/crypto.h>
#include <ipxe/hmac.h>
#include <ipxe/hmac_drbg.h>
/**
* Update the HMAC_DRBG key
*
* @v state HMAC_DRBG internal state
* @v data Provided data
* @v len Length of provided data
* @v single Single byte used in concatenation
*
* This function carries out the operation
*
* K = HMAC ( K, V || single || provided_data )
*
* as used by hmac_drbg_update()
*/
static void hmac_drbg_update_key ( struct hmac_drbg_state *state,
const void *data, size_t len,
const uint8_t single ) {
uint8_t context[HMAC_DRBG_CTX_SIZE];
size_t key_len = sizeof ( state->key );
DBGC ( state, "HMAC_DRBG %p provided data :\n", state );
DBGC_HDA ( state, 0, data, len );
/* Sanity checks */
assert ( state != NULL );
assert ( ( data != NULL ) || ( len == 0 ) );
assert ( ( single == 0x00 ) || ( single == 0x01 ) );
/* K = HMAC ( K, V || single || provided_data ) */
hmac_init ( &hmac_drbg_algorithm, context, state->key, &key_len );
assert ( key_len == sizeof ( state->key ) );
hmac_update ( &hmac_drbg_algorithm, context,
state->value, sizeof ( state->value ) );
hmac_update ( &hmac_drbg_algorithm, context,
&single, sizeof ( single ) );
hmac_update ( &hmac_drbg_algorithm, context, data, len );
hmac_final ( &hmac_drbg_algorithm, context, state->key, &key_len,
state->key );
assert ( key_len == sizeof ( state->key ) );
DBGC ( state, "HMAC_DRBG %p K = HMAC ( K, V || %#02x || "
"provided_data ) :\n", state, single );
DBGC_HDA ( state, 0, state->key, sizeof ( state->key ) );
}
/**
* Update the HMAC_DRBG value
*
* @v state HMAC_DRBG internal state
* @v data Provided data
* @v len Length of provided data
* @v single Single byte used in concatenation
*
* This function carries out the operation
*
* V = HMAC ( K, V )
*
* as used by hmac_drbg_update() and hmac_drbg_generate()
*/
static void hmac_drbg_update_value ( struct hmac_drbg_state *state ) {
uint8_t context[HMAC_DRBG_CTX_SIZE];
size_t key_len = sizeof ( state->key );
/* Sanity checks */
assert ( state != NULL );
/* V = HMAC ( K, V ) */
hmac_init ( &hmac_drbg_algorithm, context, state->key, &key_len );
assert ( key_len == sizeof ( state->key ) );
hmac_update ( &hmac_drbg_algorithm, context,
state->value, sizeof ( state->value ) );
hmac_final ( &hmac_drbg_algorithm, context, state->key, &key_len,
state->value );
assert ( key_len == sizeof ( state->key ) );
DBGC ( state, "HMAC_DRBG %p V = HMAC ( K, V ) :\n", state );
DBGC_HDA ( state, 0, state->value, sizeof ( state->value ) );
}
/**
* Update HMAC_DRBG internal state
*
* @v state HMAC_DRBG internal state
* @v data Provided data
* @v len Length of provided data
*
* This is the HMAC_DRBG_Update function defined in ANS X9.82 Part
* 3-2007 Section 10.2.2.2.2 (NIST SP 800-90 Section 10.1.2.2).
*
* The key and value are updated in-place within the HMAC_DRBG
* internal state.
*/
static void hmac_drbg_update ( struct hmac_drbg_state *state,
const void *data, size_t len ) {
DBGC ( state, "HMAC_DRBG %p update\n", state );
/* Sanity checks */
assert ( state != NULL );
assert ( ( data != NULL ) || ( len == 0 ) );
/* 1. K = HMAC ( K, V || 0x00 || provided_data ) */
hmac_drbg_update_key ( state, data, len, 0x00 );
/* 2. V = HMAC ( K, V ) */
hmac_drbg_update_value ( state );
/* 3. If ( provided_data = Null ), then return K and V */
if ( ! len )
return;
/* 4. K = HMAC ( K, V || 0x01 || provided_data ) */
hmac_drbg_update_key ( state, data, len, 0x01 );
/* 5. V = HMAC ( K, V ) */
hmac_drbg_update_value ( state );
/* 6. Return K and V */
}
/**
* Instantiate HMAC_DRBG
*
* @v state HMAC_DRBG internal state to be initialised
* @v entropy Entropy input
* @v entropy_len Length of entropy input
* @v personal Personalisation string
* @v personal_len Length of personalisation string
*
* This is the HMAC_DRBG_Instantiate_algorithm function defined in ANS
* X9.82 Part 3-2007 Section 10.2.2.2.3 (NIST SP 800-90 Section
* 10.1.2.3).
*
* The nonce must be included within the entropy input (i.e. the
* entropy input must contain at least 3/2 * security_strength bits of
* entropy, as per ANS X9.82 Part 3-2007 Section 8.4.2 (NIST SP 800-90
* Section 8.6.7).
*
* The key, value and reseed counter are updated in-place within the
* HMAC_DRBG internal state.
*/
void hmac_drbg_instantiate ( struct hmac_drbg_state *state,
const void *entropy, size_t entropy_len,
const void *personal, size_t personal_len ){
DBGC ( state, "HMAC_DRBG %p instantiate\n", state );
/* Sanity checks */
assert ( state != NULL );
assert ( entropy != NULL );
assert ( ( 8 * entropy_len ) >=
( 3 * HMAC_DRBG_SECURITY_STRENGTH / 2 ) );
assert ( ( personal != NULL ) || ( personal_len == 0 ) );
/* 1. seed_material = entropy_input || nonce ||
* personalisation_string
*/
/* 2. Key = 0x00 00..00 */
memset ( state->key, 0x00, sizeof ( state->key ) );
/* 3. V = 0x01 01...01 */
memset ( state->value, 0x01, sizeof ( state->value ) );
/* 4. ( Key, V ) = HMAC_DBRG_Update ( seed_material, Key, V )
* 5. reseed_counter = 1
* 6. Return V, Key and reseed_counter as the
* initial_working_state
*/
hmac_drbg_reseed ( state, entropy, entropy_len,
personal, personal_len );
}
/**
* Reseed HMAC_DRBG
*
* @v state HMAC_DRBG internal state
* @v entropy Entropy input
* @v entropy_len Length of entropy input
* @v additional Additional input
* @v additional_len Length of additional input
*
* This is the HMAC_DRBG_Reseed_algorithm function defined in ANS X9.82
* Part 3-2007 Section 10.2.2.2.4 (NIST SP 800-90 Section 10.1.2.4).
*
* The key, value and reseed counter are updated in-place within the
* HMAC_DRBG internal state.
*/
void hmac_drbg_reseed ( struct hmac_drbg_state *state,
const void *entropy, size_t entropy_len,
const void *additional, size_t additional_len ) {
uint8_t seed_material[ entropy_len + additional_len ];
DBGC ( state, "HMAC_DRBG %p (re)seed\n", state );
/* Sanity checks */
assert ( state != NULL );
assert ( entropy != NULL );
assert ( ( 8 * entropy_len ) >= HMAC_DRBG_SECURITY_STRENGTH );
assert ( ( additional != NULL ) || ( additional_len == 0 ) );
/* 1. seed_material = entropy_input || additional_input */
memcpy ( seed_material, entropy, entropy_len );
memcpy ( ( seed_material + entropy_len ), additional, additional_len );
DBGC ( state, "HMAC_DRBG %p seed material :\n", state );
DBGC_HDA ( state, 0, seed_material, sizeof ( seed_material ) );
/* 2. ( Key, V ) = HMAC_DBRG_Update ( seed_material, Key, V ) */
hmac_drbg_update ( state, seed_material, sizeof ( seed_material ) );
/* 3. reseed_counter = 1 */
state->reseed_counter = 1;
/* 4. Return V, Key and reseed_counter as the new_working_state */
}
/**
* Generate pseudorandom bits using HMAC_DRBG
*
* @v state HMAC_DRBG internal state
* @v additional Additional input
* @v additional_len Length of additional input
* @v data Output buffer
* @v len Length of output buffer
* @ret rc Return status code
*
* This is the HMAC_DRBG_Generate_algorithm function defined in ANS X9.82
* Part 3-2007 Section 10.2.2.2.5 (NIST SP 800-90 Section 10.1.2.5).
*
* Requests must be for an integral number of bytes.
*
* The key, value and reseed counter are updated in-place within the
* HMAC_DRBG internal state.
*
* Note that the only permitted error is "reseed required".
*/
int hmac_drbg_generate ( struct hmac_drbg_state *state,
const void *additional, size_t additional_len,
void *data, size_t len ) {
void *orig_data = data;
size_t orig_len = len;
size_t frag_len;
DBGC ( state, "HMAC_DRBG %p generate\n", state );
/* Sanity checks */
assert ( state != NULL );
assert ( data != NULL );
assert ( ( additional != NULL ) || ( additional_len == 0 ) );
/* 1. If reseed_counter > reseed_interval, then return an
* indication that a reseed is required
*/
if ( state->reseed_counter > HMAC_DRBG_RESEED_INTERVAL ) {
DBGC ( state, "HMAC_DRBG %p reseed interval exceeded\n",
state );
return -ESTALE;
}
/* 2. If additional_input != Null, then
* ( Key, V ) = HMAC_DRBG_Update ( additional_input, Key, V )
*/
if ( additional_len )
hmac_drbg_update ( state, additional, additional_len );
/* 3. temp = Null
* 4. While ( len ( temp ) < requested_number_of_bits ) do:
*/
while ( len ) {
/* 4.1 V = HMAC ( Key, V ) */
hmac_drbg_update_value ( state );
/* 4.2. temp = temp || V
* 5. returned_bits = Leftmost requested_number_of_bits
* of temp
*/
frag_len = len;
if ( frag_len > sizeof ( state->value ) )
frag_len = sizeof ( state->value );
memcpy ( data, state->value, frag_len );
data += frag_len;
len -= frag_len;
}
/* 6. ( Key, V ) = HMAC_DRBG_Update ( additional_input, Key, V ) */
hmac_drbg_update ( state, additional, additional_len );
/* 7. reseed_counter = reseed_counter + 1 */
state->reseed_counter++;
DBGC ( state, "HMAC_DRBG %p generated :\n", state );
DBGC_HDA ( state, 0, orig_data, orig_len );
/* 8. Return SUCCESS, returned_bits, and the new values of
* Key, V and reseed_counter as the new_working_state
*/
return 0;
}

1
src/include/ipxe/errfile.h
View File

@ -242,6 +242,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
#define ERRFILE_bofm ( ERRFILE_OTHER | 0x00210000 )
#define ERRFILE_prompt ( ERRFILE_OTHER | 0x00220000 )
#define ERRFILE_nvo_cmd ( ERRFILE_OTHER | 0x00230000 )
#define ERRFILE_hmac_drbg ( ERRFILE_OTHER | 0x00240000 )
/** @} */

153
src/include/ipxe/hmac_drbg.h Normal file
View File

@ -0,0 +1,153 @@
#ifndef _IPXE_HMAC_DRBG_H
#define _IPXE_HMAC_DRBG_H
/** @file
*
* HMAC_DRBG algorithm
*
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <ipxe/sha1.h>
/** Use SHA-1 as the underlying hash algorithm
*
* HMAC_DRBG using SHA-1 is an Approved algorithm in ANS X9.82.
*/
#define hmac_drbg_algorithm sha1_algorithm
/** Maximum security strength
*
* The maximum security strength of HMAC_DRBG using SHA-1 is 128 bits
* (according to the list of maximum security strengths documented in
* NIST SP 800-57 Part 1 Section 5.6.1 Table 3).
*/
#define HMAC_DRBG_MAX_SECURITY_STRENGTH 128
/** Security strength
*
* For the sake of implementation simplicity, only a single security
* strength is supported, which is the maximum security strength
* supported by the algorithm.
*/
#define HMAC_DRBG_SECURITY_STRENGTH HMAC_DRBG_MAX_SECURITY_STRENGTH
/** Underlying hash algorithm output length (in bytes) */
#define HMAC_DRBG_OUTLEN_BYTES SHA1_DIGEST_SIZE
/** Required minimum entropy for instantiate and reseed
*
* The minimum required entropy for HMAC_DRBG is equal to the security
* strength according to ANS X9.82 Part 3-2007 Section 10.2.1 Table 2
* (NIST SP 800-90 Section 10.1 Table 2).
*/
#define HMAC_DRBG_MIN_ENTROPY_BYTES ( HMAC_DRBG_SECURITY_STRENGTH / 8 )
/** Minimum entropy input length
*
* The minimum entropy input length for HMAC_DRBG is equal to the
* security strength according to ANS X9.82 Part 3-2007 Section 10.2.1
* Table 2 (NIST SP 800-90 Section 10.1 Table 2).
*/
#define HMAC_DRBG_MIN_ENTROPY_LEN_BYTES ( HMAC_DRBG_SECURITY_STRENGTH / 8 )
/** Maximum entropy input length
*
* The maximum entropy input length for HMAC_DRBG is 2^35 bits
* according to ANS X9.82 Part 3-2007 Section 10.2.1 Table 2 (NIST SP
* 800-90 Section 10.1 Table 2).
*
* We choose to allow up to 2^32-1 bytes (i.e. 2^35-8 bits).
*/
#define HMAC_DRBG_MAX_ENTROPY_LEN_BYTES 0xffffffffUL
/** Maximum personalisation string length
*
* The maximum permitted personalisation string length for HMAC_DRBG
* is 2^35 bits according to ANS X9.82 Part 3-2007 Section 10.2.1
* Table 1 (NIST SP 800-90 Section 10.1 Table 2).
*
* We choose to allow up to 2^32-1 bytes (i.e. 2^35-8 bits).
*/
#define HMAC_DRBG_MAX_PERSONAL_LEN_BYTES 0xffffffffUL
/** Maximum additional input length
*
* The maximum permitted additional input length for HMAC_DRBG is 2^35
* bits according to ANS X9.82 Part 3-2007 Section 10.2.1 Table 1
* (NIST SP 800-90 Section 10.1 Table 2).
*
* We choose to allow up to 2^32-1 bytes (i.e. 2^35-8 bits).
*/
#define HMAC_DRBG_MAX_ADDITIONAL_LEN_BYTES 0xffffffffUL
/** Maximum length of generated pseudorandom data per request
*
* The maximum number of bits per request for HMAC_DRBG is 2^19 bits
* according to ANS X9.82 Part 3-2007 Section 10.2.1 Table 1 (NIST SP
* 800-90 Section 10.1 Table 2).
*
* We choose to allow up to 2^16-1 bytes (i.e. 2^19-8 bits).
*/
#define HMAC_DRBG_MAX_GENERATED_LEN_BYTES 0x0000ffffUL
/** Reseed interval
*
* The maximum permitted reseed interval for HMAC_DRBG using SHA-1 is
* 2^48 according to ANS X9.82 Part 3-2007 Section 10.2.1 Table 2
* (NIST SP 800-90 Section 10.1 Table 2). However, the sample
* implementation given in ANS X9.82 Part 3-2007 Annex E.2.1 (NIST SP
* 800-90 Appendix F.2) shows a reseed interval of 10000.
*
* We choose a very conservative reseed interval.
*/
#define HMAC_DRBG_RESEED_INTERVAL 1024
/** Underlying hash algorithm context size (in bytes) */
#define HMAC_DRBG_CTX_SIZE SHA1_CTX_SIZE
/**
* HMAC_DRBG internal state
*
* This structure is defined by ANS X9.82 Part 3-2007 Section
* 10.2.2.2.1 (NIST SP 800-90 Section 10.1.2.1).
*
* The "administrative information" portions (security_strength and
* prediction_resistance) are design-time constants and so are not
* present as fields in this structure.
*/
struct hmac_drbg_state {
/** Current value
*
* "The value V of outlen bits, which is updated each time
* another outlen bits of output are produced"
*/
uint8_t value[HMAC_DRBG_OUTLEN_BYTES];
/** Current key
*
* "The outlen-bit Key, which is updated at least once each
* time that the DRBG mechanism generates pseudorandom bits."
*/
uint8_t key[HMAC_DRBG_OUTLEN_BYTES];
/** Reseed counter
*
* "A counter (reseed_counter) that indicates the number of
* requests for pseudorandom bits since instantiation or
* reseeding"
*/
unsigned int reseed_counter;
};
extern void hmac_drbg_instantiate ( struct hmac_drbg_state *state,
const void *entropy, size_t entropy_len,
const void *personal, size_t personal_len );
extern void hmac_drbg_reseed ( struct hmac_drbg_state *state,
const void *entropy, size_t entropy_len,
const void *additional, size_t additional_len );
extern int hmac_drbg_generate ( struct hmac_drbg_state *state,
const void *additional, size_t additional_len,
void *data, size_t len );
#endif /* _IPXE_HMAC_DRBG_H */