Implement continuous RNG test for SP800-90 DRBGs.

This commit is contained in:
Dr. Stephen Henson 2011-03-17 18:53:33 +00:00
parent 96ec46f7c0
commit 1e803100de
4 changed files with 76 additions and 2 deletions

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@ -84,6 +84,7 @@ static ERR_STRING_DATA FIPS_str_functs[]=
{ERR_FUNC(FIPS_F_FIPS_CIPHERINIT), "FIPS_CIPHERINIT"},
{ERR_FUNC(FIPS_F_FIPS_DIGESTINIT), "FIPS_DIGESTINIT"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_GENERATE), "FIPS_drbg_generate"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_GENERATE_INTERNAL), "FIPS_DRBG_GENERATE_INTERNAL"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_HEALTH_CHECK), "FIPS_DRBG_HEALTH_CHECK"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_INIT), "FIPS_drbg_init"},
{ERR_FUNC(FIPS_F_FIPS_DRBG_INSTANTIATE), "FIPS_drbg_instantiate"},
@ -118,6 +119,7 @@ static ERR_STRING_DATA FIPS_str_reasons[]=
{ERR_REASON(FIPS_R_CANNOT_READ_EXE) ,"cannot read exe"},
{ERR_REASON(FIPS_R_CANNOT_READ_EXE_DIGEST),"cannot read exe digest"},
{ERR_REASON(FIPS_R_CONTRADICTING_EVIDENCE),"contradicting evidence"},
{ERR_REASON(FIPS_R_DRBG_STUCK) ,"drbg stuck"},
{ERR_REASON(FIPS_R_ENTROPY_ERROR_UNDETECTED),"entropy error undetected"},
{ERR_REASON(FIPS_R_ENTROPY_NOT_REQUESTED_FOR_RESEED),"entropy not requested for reseed"},
{ERR_REASON(FIPS_R_ERROR_INITIALISING_DRBG),"error initialising drbg"},

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@ -194,6 +194,7 @@ void ERR_load_FIPS_strings(void);
#define FIPS_F_FIPS_CIPHERINIT 128
#define FIPS_F_FIPS_DIGESTINIT 127
#define FIPS_F_FIPS_DRBG_GENERATE 132
#define FIPS_F_FIPS_DRBG_GENERATE_INTERNAL 138
#define FIPS_F_FIPS_DRBG_HEALTH_CHECK 137
#define FIPS_F_FIPS_DRBG_INIT 136
#define FIPS_F_FIPS_DRBG_INSTANTIATE 133
@ -225,6 +226,7 @@ void ERR_load_FIPS_strings(void);
#define FIPS_R_CANNOT_READ_EXE 103
#define FIPS_R_CANNOT_READ_EXE_DIGEST 104
#define FIPS_R_CONTRADICTING_EVIDENCE 114
#define FIPS_R_DRBG_STUCK 142
#define FIPS_R_ENTROPY_ERROR_UNDETECTED 133
#define FIPS_R_ENTROPY_NOT_REQUESTED_FOR_RESEED 134
#define FIPS_R_ERROR_INITIALISING_DRBG 120

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@ -263,7 +263,8 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx,
}
int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
static int fips_drbg_generate_internal(DRBG_CTX *dctx,
unsigned char *out, size_t outlen,
int strength, int prediction_resistance,
const unsigned char *adin, size_t adinlen)
{
@ -313,13 +314,76 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
if (r)
{
if (!(dctx->flags & DRBG_FLAG_NOERR))
FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
FIPSerr(FIPS_F_FIPS_DRBG_GENERATE_INTERNAL, r);
return 0;
}
return 1;
}
/* external generate function: incorporates continuous RNG test if not
* in test mode.
*/
int FIPS_drbg_generate(DRBG_CTX *dctx,
unsigned char *out, size_t outlen,
int strength, int prediction_resistance,
const unsigned char *adin, size_t adinlen)
{
unsigned char tmp[16], *pout;
size_t poutlen;
/* If test mode don't run continuous RNG test */
if (dctx->flags & DRBG_FLAG_TEST)
{
return fips_drbg_generate_internal(dctx, out, outlen,
strength,
prediction_resistance,
adin, adinlen);
}
/* If this is the first call generate block and save buffer */
if (!dctx->lb_valid)
{
if (!fips_drbg_generate_internal(dctx, dctx->lb, 16,
strength, prediction_resistance,
adin, adinlen))
return 0;
dctx->lb_valid = 1;
}
/* If request less that 16 bytes request 16 in temp buffer */
if (outlen < 16)
{
pout = tmp;
poutlen = 16;
}
else
{
pout = out;
poutlen = outlen;
}
/* Generate data */
if (!fips_drbg_generate_internal(dctx, pout, poutlen,
strength, prediction_resistance,
adin, adinlen))
return 0;
/* Compare to last block for continuous PRNG test */
if (!memcmp(pout, dctx->lb, 16))
{
FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, FIPS_R_DRBG_STUCK);
return 0;
}
/* Update last block */
memcpy(dctx->lb, pout, 16);
/* Copy to output buffer if needed */
if (outlen < 16)
memcpy(out, pout, outlen);
return 1;
}
int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
{
int rv;

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@ -167,6 +167,12 @@ struct drbg_ctx_st
size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char *out,
int entropy, size_t min_len, size_t max_len);
/* Continuous random number test temporary area */
/* Last block */
unsigned char lb[16];
/* set if lb is valid */
int lb_valid;
};