Add support for Dual EC DRBG from SP800-90. Include updates to algorithm
[openssl.git] / fips / rand / fips_drbg_lib.c
index 31c5a7a8b003c7d6ad3eb9654a7c1b331e416944..114f78e6ab33abf6f9abdda3f869f87e7e95b1bf 100644 (file)
@@ -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"
@@ -71,10 +69,18 @@ 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;
+
        rv = fips_drbg_hash_init(dctx);
 
        if (rv == -2)
                rv = fips_drbg_ctr_init(dctx);
+       if (rv == -2)
+               rv = fips_drbg_hmac_init(dctx);
+       if (rv == -2)
+               rv = fips_drbg_ec_init(dctx);
 
        if (rv <= 0)
                {
@@ -84,12 +90,24 @@ int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
                        FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_ERROR_INITIALISING_DRBG);
                }
 
+       /* If not in test mode run selftests on DRBG of the same type */
+
+       if (!(dctx->flags & DRBG_FLAG_TEST))
+               {
+               DRBG_CTX tctx;
+               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;
+                       }
+               }
+
        return rv;
        }
 
 DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
        {
-       int rv;
        DRBG_CTX *dctx;
        dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
        if (!dctx)
@@ -99,7 +117,6 @@ DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
                }
        if (type == 0)
                return dctx;
-       rv = FIPS_drbg_init(dctx, type, flags);
 
        if (FIPS_drbg_init(dctx, type, flags) <= 0)
                {
@@ -112,16 +129,57 @@ DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
 
 void FIPS_drbg_free(DRBG_CTX *dctx)
        {
-       dctx->uninstantiate(dctx);
-       OPENSSL_cleanse(dctx, sizeof(DRBG_CTX));
+       if (dctx->uninstantiate)
+               dctx->uninstantiate(dctx);
+       OPENSSL_cleanse(&dctx->d, sizeof(dctx->d));
        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,
-                               int strength,
                                const unsigned char *pers, size_t perslen)
        {
-       size_t entlen, noncelen;
+       size_t entlen = 0, noncelen = 0;
+       unsigned char *nonce = NULL, *entropy = NULL;
 
 #if 0
        /* Put here so error script picks them up */
@@ -151,15 +209,9 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
                goto end;
                }
 
-       if (strength > dctx->strength)
-               {
-               r = FIPS_R_INSUFFICIENT_SECURITY_STRENGTH;
-               goto end;
-               }
-
        dctx->status = DRBG_STATUS_ERROR;
 
-       entlen = dctx->get_entropy(dctx, 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)
@@ -170,8 +222,7 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 
        if (dctx->max_nonce > 0)
                {
-
-               noncelen = dctx->get_nonce(dctx, dctx->nonce,
+               noncelen = dctx->get_nonce(dctx, &nonce,
                                        dctx->strength / 2,
                                        dctx->min_nonce, dctx->max_nonce);
 
@@ -182,12 +233,10 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
                        }
 
                }
-       else
-               noncelen = 0;
 
        if (!dctx->instantiate(dctx, 
-                               dctx->entropy, entlen,
-                               dctx->nonce, noncelen,
+                               entropy, entlen,
+                               nonce, noncelen,
                                pers, perslen))
                {
                r = FIPS_R_ERROR_INSTANTIATING_DRBG;
@@ -196,19 +245,21 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 
 
        dctx->status = DRBG_STATUS_READY;
-       dctx->reseed_counter = 1;
-       /* Initial test value for reseed interval */
-       dctx->reseed_interval = 1<<24;
+       if (!(dctx->flags & DRBG_CUSTOM_RESEED))
+               dctx->reseed_counter = 1;
 
        end:
 
-       OPENSSL_cleanse(dctx->entropy, sizeof(dctx->entropy));
-       OPENSSL_cleanse(dctx->nonce, sizeof(dctx->nonce));
+       if (entropy && dctx->cleanup_entropy)
+               fips_cleanup_entropy(dctx, entropy, entlen);
+
+       if (nonce && dctx->cleanup_nonce)
+               dctx->cleanup_nonce(dctx, nonce, noncelen);
 
        if (dctx->status == DRBG_STATUS_READY)
                return 1;
 
-       if (r && !(dctx->flags & DRBG_FLAG_TEST))
+       if (r && !(dctx->flags & DRBG_FLAG_NOERR))
                FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);
 
        return 0;
@@ -218,6 +269,7 @@ int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 int FIPS_drbg_reseed(DRBG_CTX *dctx,
                        const unsigned char *adin, size_t adinlen)
        {
+       unsigned char *entropy = NULL;
        size_t entlen;
        int r = 0;
 
@@ -245,7 +297,7 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx,
 
        dctx->status = DRBG_STATUS_ERROR;
 
-       entlen = dctx->get_entropy(dctx, 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)
@@ -254,29 +306,65 @@ int FIPS_drbg_reseed(DRBG_CTX *dctx,
                goto end;
                }
 
-       if (!dctx->reseed(dctx, dctx->entropy, entlen, adin, adinlen))
+       if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
                goto end;
 
        dctx->status = DRBG_STATUS_READY;
-       dctx->reseed_counter = 1;
+       if (!(dctx->flags & DRBG_CUSTOM_RESEED))
+               dctx->reseed_counter = 1;
        end:
-       OPENSSL_cleanse(dctx->entropy, sizeof(dctx->entropy));
+
+       if (entropy && dctx->cleanup_entropy)
+               fips_cleanup_entropy(dctx, entropy, entlen);
 
        if (dctx->status == DRBG_STATUS_READY)
                return 1;
 
-       if (r && !(dctx->flags & DRBG_FLAG_TEST))
+       if (r && !(dctx->flags & DRBG_FLAG_NOERR))
                FIPSerr(FIPS_F_FIPS_DRBG_RESEED, r);
 
        return 0;
        }
 
+static int fips_drbg_check(DRBG_CTX *dctx)
+       {
+       if (dctx->flags & DRBG_FLAG_TEST)
+               return 1;
+       dctx->health_check_cnt++;
+       if (dctx->health_check_cnt >= dctx->health_check_interval)
+               {
+               DRBG_CTX tctx;
+               if (!fips_drbg_kat(&tctx, dctx->type,
+                                               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;
+               }
+       return 1;
+       }
 
 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)
        {
        int r = 0;
+
+       if (!fips_drbg_check(dctx))
+               return 0;
+
+       if (dctx->status != DRBG_STATUS_READY
+               && dctx->status != DRBG_STATUS_RESEED)
+               {
+               if (dctx->status == DRBG_STATUS_ERROR)
+                       r = FIPS_R_IN_ERROR_STATE;
+               else if(dctx->status == DRBG_STATUS_UNINITIALISED)
+                       r = FIPS_R_NOT_INSTANTIATED;
+               goto end;
+               }
+
        if (outlen > dctx->max_request)
                {
                r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
@@ -289,6 +377,11 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
                goto end;
                }
 
+       if (dctx->flags & DRBG_CUSTOM_RESEED)
+               dctx->generate(dctx, NULL, outlen, NULL, 0);
+       else if (dctx->reseed_counter >= dctx->reseed_interval)
+               dctx->status = DRBG_STATUS_RESEED;
+
        if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
                {
                if (!FIPS_drbg_reseed(dctx, adin, adinlen))
@@ -299,29 +392,25 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
                adin = NULL;
                adinlen = 0;
                }
-       if (dctx->status != DRBG_STATUS_READY)
-               {
-               if (dctx->status == DRBG_STATUS_ERROR)
-                       r = FIPS_R_IN_ERROR_STATE;
-               else if(dctx->status == DRBG_STATUS_UNINITIALISED)
-                       r = FIPS_R_NOT_INSTANTIATED;
-               goto end;
-               }
+
        if (!dctx->generate(dctx, out, outlen, adin, adinlen))
                {
                r = FIPS_R_GENERATE_ERROR;
                dctx->status = DRBG_STATUS_ERROR;
                goto end;
                }
-       if (dctx->reseed_counter > dctx->reseed_interval)
-               dctx->status = DRBG_STATUS_RESEED;
-       else
-               dctx->reseed_counter++;
+       if (!(dctx->flags & DRBG_CUSTOM_RESEED))
+               {
+               if (dctx->reseed_counter >= dctx->reseed_interval)
+                       dctx->status = DRBG_STATUS_RESEED;
+               else
+                       dctx->reseed_counter++;
+               }
 
        end:
        if (r)
                {
-               if (!(dctx->flags & DRBG_FLAG_TEST))
+               if (!(dctx->flags & DRBG_FLAG_NOERR))
                        FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
                return 0;
                }
@@ -331,26 +420,52 @@ int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 
 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
        {
-       int save_type, save_flags, rv;
-       save_type = dctx->type;
-       save_flags = dctx->flags;
-       rv = dctx->uninstantiate(dctx);
-       OPENSSL_cleanse(dctx, sizeof(DRBG_CTX));
+       int rv;
+       if (!dctx->uninstantiate)
+               rv = 1;
+       else
+               rv = dctx->uninstantiate(dctx);
+       /* Although we'd like to cleanse here we can't because we have to
+        * test the uninstantiate really zeroes the data.
+        */
+       memset(&dctx->d, 0, sizeof(dctx->d));
+       dctx->status = DRBG_STATUS_UNINITIALISED;
        /* If method has problems uninstantiating, return error */
        return rv;
        }
 
-int FIPS_drbg_set_test_mode(DRBG_CTX *dctx,
-       size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char *out,
+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),
-       size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char *out,
-                               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->flags |= DRBG_FLAG_TEST;
+       dctx->entropy_blocklen = entropy_blocklen;
        dctx->get_entropy = get_entropy;
+       dctx->cleanup_entropy = cleanup_entropy;
        dctx->get_nonce = get_nonce;
+       dctx->cleanup_nonce = cleanup_nonce;
+       return 1;
+       }
+
+int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
+       size_t (*get_adin)(DRBG_CTX *ctx, unsigned char **pout),
+       void (*cleanup_adin)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
+       int (*rand_seed_cb)(DRBG_CTX *ctx, const void *buf, int num),
+       int (*rand_add_cb)(DRBG_CTX *ctx,
+                               const void *buf, int num, double entropy))
+       {
+       if (dctx->status != DRBG_STATUS_UNINITIALISED)
+               return 0;
+       dctx->get_adin = get_adin;
+       dctx->cleanup_adin = cleanup_adin;
+       dctx->rand_seed_cb = rand_seed_cb;
+       dctx->rand_add_cb = rand_add_cb;
        return 1;
        }
 
@@ -373,3 +488,42 @@ int FIPS_drbg_get_strength(DRBG_CTX *dctx)
        {
        return dctx->strength;
        }
+
+void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
+       {
+       dctx->health_check_interval = interval;
+       }
+
+static int drbg_stick = 0;
+
+void FIPS_drbg_stick(void)
+       {
+       drbg_stick = 1;
+       }
+
+/* Continuous DRBG utility function */
+int fips_drbg_cprng_test(DRBG_CTX *dctx, const unsigned char *out)
+       {
+       /* No CPRNG in test mode */
+       if (dctx->flags & DRBG_FLAG_TEST)
+               return 1;
+       /* Check block is valid: should never happen */
+       if (dctx->lb_valid == 0)
+               {
+               FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
+               fips_set_selftest_fail();
+               return 0;
+               }
+       if (drbg_stick)
+               memcpy(dctx->lb, out, dctx->blocklength);
+       /* Check against last block: fail if match */
+       if (!memcmp(dctx->lb, out, dctx->blocklength))
+               {
+               FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
+               fips_set_selftest_fail();
+               return 0;
+               }
+       /* Save last block for next comparison */
+       memcpy(dctx->lb, out, dctx->blocklength);
+       return 1;
+       }