Entropy collector and CTR-DRBG now also work on SHA-256 if SHA-512 not available

This commit is contained in:
Paul Bakker 2013-08-27 15:06:26 +02:00
parent 0a20171d52
commit fb08fd2e23
6 changed files with 65 additions and 5 deletions

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@ -1326,7 +1326,7 @@
// CTR_DRBG options
//
#define CTR_DRBG_ENTROPY_LEN 48 /**< Amount of entropy used per seed by default */
#define CTR_DRBG_ENTROPY_LEN 48 /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */
#define CTR_DRBG_RESEED_INTERVAL 10000 /**< Interval before reseed is performed by default */
#define CTR_DRBG_MAX_INPUT 256 /**< Maximum number of additional input bytes */
#define CTR_DRBG_MAX_REQUEST 1024 /**< Maximum number of requested bytes per call */
@ -1382,9 +1382,18 @@
#error "POLARSSL_ECP_C defined, but not all prerequisites"
#endif
#if defined(POLARSSL_ENTROPY_C) && !defined(POLARSSL_SHA512_C)
#if defined(POLARSSL_ENTROPY_C) && (!defined(POLARSSL_SHA512_C) && \
!defined(POLARSSL_SHA256_C))
#error "POLARSSL_ENTROPY_C defined, but not all prerequisites"
#endif
#if defined(POLARSSL_ENTROPY_C) && defined(POLARSSL_SHA512_C) && \
defined(POLARSSL_CONFIG_OPTIONS) && (CTR_DRBG_ENTROPY_LEN > 64)
#error "CTR_DRBG_ENTROPY_LEN value too high"
#endif
#if defined(POLARSSL_ENTROPY_C) && !defined(POLARSSL_SHA512_C) && \
defined(POLARSSL_CONFIG_OPTIONS) && (CTR_DRBG_ENTROPY_LEN > 32)
#error "CTR_DRBG_ENTROPY_LEN value too high"
#endif
#if defined(POLARSSL_GCM_C) && !defined(POLARSSL_AES_C)
#error "POLARSSL_GCM_C defined, but not all prerequisites"

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@ -43,7 +43,11 @@
/**< The seed length (counter + AES key) */
#if !defined(POLARSSL_CONFIG_OPTIONS)
#define CTR_DRBG_ENTROPY_LEN 48 /**< Amount of entropy used per seed by default */
#if defined(POLARSSL_SHA512_C)
#define CTR_DRBG_ENTROPY_LEN 48 /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */
#else
#define CTR_DRBG_ENTROPY_LEN 32 /**< Amount of entropy used per seed by default (48 with SHA-512, 32 with SHA-256) */
#endif
#define CTR_DRBG_RESEED_INTERVAL 10000 /**< Interval before reseed is performed by default */
#define CTR_DRBG_MAX_INPUT 256 /**< Maximum number of additional input bytes */
#define CTR_DRBG_MAX_REQUEST 1024 /**< Maximum number of requested bytes per call */

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@ -31,7 +31,16 @@
#include "config.h"
#if defined(POLARSSL_SHA512_C)
#include "sha512.h"
#define POLARSSL_ENTROPY_SHA512_ACCUMULATOR
#else
#if defined(POLARSSL_SHA256_C)
#define POLARSSL_ENTROPY_SHA256_ACCUMULATOR
#include "sha256.h"
#endif
#endif
#if defined(POLARSSL_HAVEGE_C)
#include "havege.h"
#endif
@ -45,7 +54,11 @@
#define ENTROPY_MAX_GATHER 128 /**< Maximum amount requested from entropy sources */
#endif /* !POLARSSL_CONFIG_OPTIONS */
#if defined(POLARSSL_ENTROPY_SHA512_ACCUMULATOR)
#define ENTROPY_BLOCK_SIZE 64 /**< Block size of entropy accumulator (SHA-512) */
#else
#define ENTROPY_BLOCK_SIZE 32 /**< Block size of entropy accumulator (SHA-256) */
#endif
#define ENTROPY_SOURCE_MANUAL ENTROPY_MAX_SOURCES
@ -83,7 +96,11 @@ source_state;
*/
typedef struct
{
#if defined(POLARSSL_ENTROPY_SHA512_ACCUMULATOR)
sha512_context accumulator;
#else
sha256_context accumulator;
#endif
int source_count;
source_state source[ENTROPY_MAX_SOURCES];
#if defined(POLARSSL_HAVEGE_C)

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@ -439,7 +439,9 @@ struct _ssl_handshake_params
md5_context fin_md5;
sha1_context fin_sha1;
sha256_context fin_sha256;
#if defined(POLARSSL_SHA512_C)
sha512_context fin_sha512;
#endif
void (*update_checksum)(ssl_context *, const unsigned char *, size_t);
void (*calc_verify)(ssl_context *, unsigned char *);

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@ -40,7 +40,11 @@ void entropy_init( entropy_context *ctx )
{
memset( ctx, 0, sizeof(entropy_context) );
#if defined(POLARSSL_ENTROPY_SHA512_ACCUMULATOR)
sha512_starts( &ctx->accumulator, 0 );
#else
sha256_starts( &ctx->accumulator, 0 );
#endif
#if defined(POLARSSL_HAVEGE_C)
havege_init( &ctx->havege_data );
#endif
@ -91,8 +95,11 @@ static int entropy_update( entropy_context *ctx, unsigned char source_id,
if( use_len > ENTROPY_BLOCK_SIZE )
{
#if defined(POLARSSL_ENTROPY_SHA512_ACCUMULATOR)
sha512( data, len, tmp, 0 );
#else
sha256( data, len, tmp, 0 );
#endif
p = tmp;
use_len = ENTROPY_BLOCK_SIZE;
}
@ -100,8 +107,13 @@ static int entropy_update( entropy_context *ctx, unsigned char source_id,
header[0] = source_id;
header[1] = use_len & 0xFF;
#if defined(POLARSSL_ENTROPY_SHA512_ACCUMULATOR)
sha512_update( &ctx->accumulator, header, 2 );
sha512_update( &ctx->accumulator, p, use_len );
#else
sha256_update( &ctx->accumulator, header, 2 );
sha256_update( &ctx->accumulator, p, use_len );
#endif
return( 0 );
}
@ -179,6 +191,7 @@ int entropy_func( void *data, unsigned char *output, size_t len )
memset( buf, 0, ENTROPY_BLOCK_SIZE );
#if defined(POLARSSL_ENTROPY_SHA512_ACCUMULATOR)
sha512_finish( &ctx->accumulator, buf );
/*
@ -192,6 +205,21 @@ int entropy_func( void *data, unsigned char *output, size_t len )
memset( &ctx->accumulator, 0, sizeof( sha512_context ) );
sha512_starts( &ctx->accumulator, 0 );
sha512_update( &ctx->accumulator, buf, ENTROPY_BLOCK_SIZE );
#else /* POLARSSL_ENTROPY_SHA512_ACCUMULATOR */
sha256_finish( &ctx->accumulator, buf );
/*
* Perform second SHA-256 on entropy
*/
sha256( buf, ENTROPY_BLOCK_SIZE, buf, 0 );
/*
* Reset accumulator and counters and recycle existing entropy
*/
memset( &ctx->accumulator, 0, sizeof( sha256_context ) );
sha256_starts( &ctx->accumulator, 0 );
sha256_update( &ctx->accumulator, buf, ENTROPY_BLOCK_SIZE );
#endif /* POLARSSL_ENTROPY_SHA512_ACCUMULATOR */
for( i = 0; i < ctx->source_count; i++ )
ctx->source[i].size = 0;

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@ -2318,7 +2318,7 @@ void ssl_optimize_checksum( ssl_context *ssl,
const ssl_ciphersuite_t *ciphersuite_info )
{
#if !defined(POLARSSL_SHA512_C)
((void) ciphersuite);
((void) ciphersuite_info);
#endif
if( ssl->minor_ver < SSL_MINOR_VERSION_3 )