Place DRBG in error state if health check fails.

[openssl.git] / fips / rand / fips_drbg_lib.c

diff --git a/fips/rand/fips_drbg_lib.c b/fips/rand/fips_drbg_lib.c
index 6d983aaf4bdede5653a19ec2840f3d483a2eebe4..f5f365b01e327ace8d5feb311399f49a1109dcf7 100644 (file)
--- a/fips/rand/fips_drbg_lib.c
+++ b/fips/rand/fips_drbg_lib.c
@@ -55,8 +55,6 @@
 
 #include <string.h>
 #include <openssl/crypto.h>
-#include <openssl/evp.h>
-#include <openssl/aes.h>
 #include <openssl/err.h>
 #include <openssl/fips_rand.h>
 #include "fips_rand_lcl.h"
@@ -71,6 +69,7 @@ int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
        dctx->flags = flags;
        dctx->type = type;
 
+       dctx->entropy_blocklen = 0;
        dctx->health_check_cnt = 0;
        dctx->health_check_interval = DRBG_HEALTH_INTERVAL;
 
@@ -78,6 +77,8 @@ int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
 
        if (rv == -2)
                rv = fips_drbg_ctr_init(dctx);
+       if (rv == -2)
+               rv = fips_drbg_hmac_init(dctx);
 
        if (rv <= 0)
                {
@@ -95,6 +96,7 @@ int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
                if (!fips_drbg_kat(&tctx, type, flags | DRBG_FLAG_TEST))
                        {
                        FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_SELFTEST_FAILURE);
+                       dctx->status = DRBG_STATUS_ERROR;
                        return 0;
                        }
                }
@@ -131,6 +133,46 @@ void FIPS_drbg_free(DRBG_CTX *dctx)
        OPENSSL_free(dctx);
        }
 
+static size_t fips_get_entropy(DRBG_CTX *dctx, unsigned char **pout,
+                               int entropy, size_t min_len, size_t max_len)
+       {
+       unsigned char *tout, *p;
+       size_t bl = dctx->entropy_blocklen, rv;
+       if (dctx->flags & DRBG_FLAG_TEST || !bl)
+               return dctx->get_entropy(dctx, pout, entropy, min_len, max_len);
+       rv = dctx->get_entropy(dctx, &tout, entropy + bl,
+                               min_len + bl, max_len + bl);
+       *pout = tout + bl;
+       if (rv < (min_len + bl) || (rv % bl))
+               return 0;
+       /* Compare consecutive blocks for continuous PRNG test */
+       for (p = tout; p < tout + rv - bl; p += bl)
+               {
+               if (!memcmp(p, p + bl, bl))
+                       {
+                       FIPSerr(FIPS_F_FIPS_GET_ENTROPY, FIPS_R_ENTROPY_SOURCE_STUCK);
+                       return 0;
+                       }
+               }
+       rv -= bl;
+       if (rv > max_len)
+               return max_len;
+       return rv;
+       }
+
+static void fips_cleanup_entropy(DRBG_CTX *dctx,
+                                       unsigned char *out, size_t olen)
+       {
+       size_t bl;
+       if (dctx->flags & DRBG_FLAG_TEST)
+               bl = 0;
+       else
+               bl = dctx->entropy_blocklen;
+       /* Call cleanup with original arguments */
+       dctx->cleanup_entropy(dctx, out - bl, olen + bl);
+       }
+
+
 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
                                const unsigned char *pers, size_t perslen)
        {
@@ -167,7 +209,7 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 
        dctx->status = DRBG_STATUS_ERROR;
 
-       entlen = dctx->get_entropy(dctx, &entropy, dctx->strength,
+       entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
                                dctx->min_entropy, dctx->max_entropy);
 
        if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
@@ -206,7 +248,7 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
        end:
 
        if (entropy && dctx->cleanup_entropy)
-               dctx->cleanup_entropy(dctx, entropy, entlen);
+               fips_cleanup_entropy(dctx, entropy, entlen);
 
        if (nonce && dctx->cleanup_nonce)
                dctx->cleanup_nonce(dctx, nonce, noncelen);
@@ -252,7 +294,7 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx,
 
        dctx->status = DRBG_STATUS_ERROR;
 
-       entlen = dctx->get_entropy(dctx, &entropy, dctx->strength,
+       entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
                                dctx->min_entropy, dctx->max_entropy);
 
        if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
@@ -269,7 +311,7 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx,
        end:
 
        if (entropy && dctx->cleanup_entropy)
-               dctx->cleanup_entropy(dctx, entropy, entlen);
+               fips_cleanup_entropy(dctx, entropy, entlen);
 
        if (dctx->status == DRBG_STATUS_READY)
                return 1;
@@ -292,6 +334,7 @@ static int fips_drbg_check(DRBG_CTX *dctx)
                                                dctx->flags | DRBG_FLAG_TEST))
                        {
                        FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
+                       dctx->status = DRBG_STATUS_ERROR;
                        return 0;
                        }
                dctx->health_check_cnt = 0;
@@ -383,12 +426,14 @@ int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
        size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
                                int entropy, size_t min_len, size_t max_len),
        void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
+       size_t entropy_blocklen,
        size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
                                int entropy, size_t min_len, size_t max_len),
        void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
        {
        if (dctx->status != DRBG_STATUS_UNINITIALISED)
                return 0;
+       dctx->entropy_blocklen = entropy_blocklen;
        dctx->get_entropy = get_entropy;
        dctx->cleanup_entropy = cleanup_entropy;
        dctx->get_nonce = get_nonce;