Add functions returning security bits.
[openssl.git] / crypto / dsa / dsa_gen.c
index 4d6bbc0..9e3e57a 100644 (file)
@@ -141,7 +141,7 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
            goto err;
            }
 
-       if (FIPS_mode() && !(ret->flags & DSA_FLAG_NON_FIPS_ALLOW) 
+       if (FIPS_module_mode() && !(ret->flags & DSA_FLAG_NON_FIPS_ALLOW) 
                        && (bits < OPENSSL_DSA_FIPS_MIN_MODULUS_BITS))
                {
                DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN, DSA_R_KEY_SIZE_TOO_SMALL);
@@ -372,6 +372,8 @@ err:
        return ok;
        }
 
+#ifdef OPENSSL_FIPS
+
 /* Security strength of parameter values for (L,N): see FIPS186-3 4.2
  * and SP800-131A
  */
@@ -403,14 +405,14 @@ static int dsa2_valid_parameters(size_t L, size_t N)
        if (L == 2048 && N == 256)
                return 112;
        if (L == 3072 && N == 256)
-               return 112;
+               return 128;
        return 0;
        }
 
 int fips_check_dsa_prng(DSA *dsa, size_t L, size_t N)
        {
        int strength;
-       if (!FIPS_mode())
+       if (!FIPS_module_mode())
                return 1;
 
        if (dsa->flags & (DSA_FLAG_NON_FIPS_ALLOW|DSA_FLAG_FIPS_CHECKED))
@@ -442,6 +444,7 @@ int fips_check_dsa_prng(DSA *dsa, size_t L, size_t N)
        return 0;
 
        }
+#endif /* OPENSSL_FIPS */
 
 /* This is a parameter generation algorithm for the DSA2 algorithm as
  * described in FIPS 186-3.
@@ -449,11 +452,11 @@ int fips_check_dsa_prng(DSA *dsa, size_t L, size_t N)
 
 int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
        const EVP_MD *evpmd, const unsigned char *seed_in, size_t seed_len,
-       unsigned char *seed_out,
+       int idx, unsigned char *seed_out,
        int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
        {
        int ok=-1;
-       unsigned char *seed = NULL;
+       unsigned char *seed = NULL, *seed_tmp = NULL;
        unsigned char md[EVP_MAX_MD_SIZE];
        int mdsize;
        BIGNUM *r0,*W,*X,*c,*test;
@@ -463,8 +466,11 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
        int counter=0;
        int r=0;
        BN_CTX *ctx=NULL;
+       EVP_MD_CTX mctx;
        unsigned int h=2;
 
+       EVP_MD_CTX_init(&mctx);
+
 #ifdef OPENSSL_FIPS
        if(FIPS_selftest_failed())
            {
@@ -488,17 +494,26 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
                }
 
        mdsize = M_EVP_MD_size(evpmd);
+       /* If unverificable g generation only don't need seed */
+       if (!ret->p || !ret->q || idx >= 0)
+               {
+               if (seed_len == 0)
+                       seed_len = mdsize;
+
+               seed = OPENSSL_malloc(seed_len);
 
-       if (seed_len == 0)
-               seed_len = mdsize;
+               if (seed_out)
+                       seed_tmp = seed_out;
+               else
+                       seed_tmp = OPENSSL_malloc(seed_len);
 
-       seed = OPENSSL_malloc(seed_len);
+               if (!seed || !seed_tmp)
+                       goto err;
 
-       if (!seed)
-               goto err;
+               if (seed_in)
+                       memcpy(seed, seed_in, seed_len);
 
-       if (seed_in)
-               memcpy(seed, seed_in, seed_len);
+               }
 
        if ((ctx=BN_CTX_new()) == NULL)
                goto err;
@@ -510,12 +525,25 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
        r0 = BN_CTX_get(ctx);
        g = BN_CTX_get(ctx);
        W = BN_CTX_get(ctx);
-       q = BN_CTX_get(ctx);
        X = BN_CTX_get(ctx);
        c = BN_CTX_get(ctx);
-       p = BN_CTX_get(ctx);
        test = BN_CTX_get(ctx);
 
+       /* if p, q already supplied generate g only */
+       if (ret->p && ret->q)
+               {
+               p = ret->p;
+               q = ret->q;
+               if (idx >= 0)
+                       memcpy(seed_tmp, seed, seed_len);
+               goto g_only;
+               }
+       else
+               {
+               p = BN_CTX_get(ctx);
+               q = BN_CTX_get(ctx);
+               }
+
        if (!BN_lshift(test,BN_value_one(),L-1))
                goto err;
        for (;;)
@@ -638,28 +666,64 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
                        /* "offset = offset + n + 1" */
 
                        /* step 14 */
-                       if (counter >= 4096) break;
+                       if (counter >= (int)(4 * L)) break;
+                       }
+               if (seed_in)
+                       {
+                       ok = 0;
+                       DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS);
+                       goto err;
                        }
                }
 end:
        if(!BN_GENCB_call(cb, 2, 1))
                goto err;
 
+       g_only:
+
        /* We now need to generate g */
        /* Set r0=(p-1)/q */
        if (!BN_sub(test,p,BN_value_one())) goto err;
        if (!BN_div(r0,NULL,test,q,ctx)) goto err;
 
-       if (!BN_set_word(test,h)) goto err;
+       if (idx < 0)
+               {
+               if (!BN_set_word(test,h))
+                       goto err;
+               }
+       else
+               h = 1;
        if (!BN_MONT_CTX_set(mont,p,ctx)) goto err;
 
        for (;;)
                {
+               __fips_constseg
+               static const unsigned char ggen[4] = {0x67,0x67,0x65,0x6e};
+               if (idx >= 0)
+                       {
+                       md[0] = idx & 0xff;
+                       md[1] = (h >> 8) & 0xff;
+                       md[2] = h & 0xff;
+                       if (!EVP_DigestInit_ex(&mctx, evpmd, NULL))
+                               goto err;
+                       if (!EVP_DigestUpdate(&mctx, seed_tmp, seed_len))
+                               goto err;
+                       if (!EVP_DigestUpdate(&mctx, ggen, sizeof(ggen)))
+                               goto err;
+                       if (!EVP_DigestUpdate(&mctx, md, 3))
+                               goto err;
+                       if (!EVP_DigestFinal_ex(&mctx, md, NULL))
+                               goto err;
+                       if (!BN_bin2bn(md, mdsize, test))
+                               goto err;
+                       }
                /* g=test^r0%p */
                if (!BN_mod_exp_mont(g,test,r0,p,ctx,mont)) goto err;
                if (!BN_is_one(g)) break;
-               if (!BN_add(test,test,BN_value_one())) goto err;
+               if (idx < 0 && !BN_add(test,test,BN_value_one())) goto err;
                h++;
+               if ( idx >= 0 && h > 0xffff)
+                       goto err;
                }
 
        if(!BN_GENCB_call(cb, 3, 1))
@@ -669,11 +733,17 @@ end:
 err:
        if (ok == 1)
                {
-               if(ret->p) BN_free(ret->p);
-               if(ret->q) BN_free(ret->q);
+               if (p != ret->p)
+                       {
+                       if(ret->p) BN_free(ret->p);
+                       ret->p=BN_dup(p);
+                       }
+               if (q != ret->q)
+                       {
+                       if(ret->q) BN_free(ret->q);
+                       ret->q=BN_dup(q);
+                       }
                if(ret->g) BN_free(ret->g);
-               ret->p=BN_dup(p);
-               ret->q=BN_dup(q);
                ret->g=BN_dup(g);
                if (ret->p == NULL || ret->q == NULL || ret->g == NULL)
                        {
@@ -685,12 +755,53 @@ err:
                }
        if (seed)
                OPENSSL_free(seed);
+       if (seed_out != seed_tmp)
+               OPENSSL_free(seed_tmp);
        if(ctx)
                {
                BN_CTX_end(ctx);
                BN_CTX_free(ctx);
                }
        if (mont != NULL) BN_MONT_CTX_free(mont);
+       EVP_MD_CTX_cleanup(&mctx);
        return ok;
        }
+
+int dsa_paramgen_check_g(DSA *dsa)
+       {
+       BN_CTX *ctx;
+       BIGNUM *tmp;
+       BN_MONT_CTX *mont = NULL;
+       int rv = -1;
+       ctx = BN_CTX_new();
+       if (!ctx)
+               return -1;
+       BN_CTX_start(ctx);
+       if (BN_cmp(dsa->g, BN_value_one()) <= 0)
+               return 0;
+       if (BN_cmp(dsa->g, dsa->p) >= 0)
+               return 0;
+       tmp = BN_CTX_get(ctx);
+       if (!tmp)
+               goto err;
+       if ((mont=BN_MONT_CTX_new()) == NULL)
+               goto err;
+       if (!BN_MONT_CTX_set(mont,dsa->p,ctx))
+               goto err;
+       /* Work out g^q mod p */
+       if (!BN_mod_exp_mont(tmp,dsa->g,dsa->q, dsa->p, ctx, mont))
+               goto err;
+       if (!BN_cmp(tmp, BN_value_one()))
+               rv = 1;
+       else
+               rv = 0;
+       err:
+       BN_CTX_end(ctx);
+       if (mont)
+               BN_MONT_CTX_free(mont);
+       BN_CTX_free(ctx);
+       return rv;
+
+       }
+
 #endif