Add support for canonical generation of DSA parameter g.
authorDr. Stephen Henson <steve@openssl.org>
Fri, 26 Aug 2011 14:51:49 +0000 (14:51 +0000)
committerDr. Stephen Henson <steve@openssl.org>
Fri, 26 Aug 2011 14:51:49 +0000 (14:51 +0000)
Modify fips_dssvs to support appropriate file format.

CHANGES
crypto/dsa/dsa_gen.c
crypto/dsa/dsa_locl.h
fips/dsa/fips_dssvs.c

diff --git a/CHANGES b/CHANGES
index 48537e8..e3362ef 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,9 @@
 
  Changes between 1.0.1 and 1.1.0  [xx XXX xxxx]
 
+  *) Add support for canonical generation of DSA parameter 'g'. See 
+     FIPS 186-3 A.2.3.
+
   *) Add support for HMAC DRBG from SP800-90. Update algorithm and POST
      to handle HMAC cases.
      [Steve Henson]
index a4a0421..2a92d06 100644 (file)
@@ -452,11 +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;
@@ -466,8 +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())
            {
@@ -497,7 +500,12 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
 
        seed = OPENSSL_malloc(seed_len);
 
-       if (!seed)
+       if (seed_out)
+               seed_tmp = seed_out;
+       else
+               seed_tmp = OPENSSL_malloc(seed_len);
+
+       if (!seed || !seed_tmp)
                goto err;
 
        if (seed_in)
@@ -513,12 +521,24 @@ 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;
+               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 (;;)
@@ -648,21 +668,50 @@ 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 (;;)
                {
+               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))
@@ -672,11 +721,17 @@ 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)
                        {
@@ -688,12 +743,53 @@ 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
index 4e07c7c..f385a7e 100644 (file)
@@ -59,7 +59,9 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
        unsigned char *seed_out,
        int *counter_ret, unsigned long *h_ret, BN_GENCB *cb);
 
-int dsa_builtin_paramgen2(DSA *ret, size_t bits, size_t qbits,
+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 dsa_paramgen_check_g(DSA *dsa);
index b6dc56d..ce1bc18 100644 (file)
@@ -111,9 +111,9 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
        const EVP_MD *evpmd, const unsigned char *seed_in, size_t seed_len,
        unsigned char *seed_out,
        int *counter_ret, unsigned long *h_ret, BN_GENCB *cb);
-int dsa_builtin_paramgen2(DSA *ret, size_t bits, size_t qbits,
+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);
 
 static void pqg(FILE *in, FILE *out)
@@ -160,7 +160,7 @@ static void pqg(FILE *in, FILE *out)
                        exit(1);
                        }
                if (dsa2 && dsa_builtin_paramgen2(dsa, L, N, md,
-                                               NULL, 0, seed,
+                                               NULL, 0, -1, seed,
                                                &counter, &h, NULL) <= 0)
                        {
                        fprintf(stderr, "Parameter Generation error\n");
@@ -191,8 +191,8 @@ static void pqgver(FILE *in, FILE *out)
     DSA *dsa=NULL;
     int dsa2, L, N, part_test = 0;
     const EVP_MD *md = NULL;
-    int seedlen=-1;
-    unsigned char seed[1024];
+    int seedlen=-1, idxlen, idx = -1;
+    unsigned char seed[1024], idtmp[1024];
 
     while(fgets(buf,sizeof buf,in) != NULL)
        {
@@ -221,7 +221,8 @@ static void pqgver(FILE *in, FILE *out)
            q=hex2bn(value);
        else if(!strcmp(keyword,"G"))
            g=hex2bn(value);
-       else if(!strcmp(keyword,"Seed"))
+       else if(!strcmp(keyword,"Seed")
+               || !strcmp(keyword,"domain_parameter_seed"))
            {
            seedlen = hex2bin(value, seed);
            if (!dsa2 && seedlen != 20)
@@ -229,9 +230,21 @@ static void pqgver(FILE *in, FILE *out)
                fprintf(stderr, "Seed parse length error\n");
                exit (1);
                }
+           if (idx > 0)
+               part_test = 1;
+           }
+       else if(!strcmp(keyword,"index"))
+           {
+           idxlen = hex2bin(value, idtmp);
+            if (idxlen != 1)
+               {
+               fprintf(stderr, "Index value error\n");
+               exit (1);
+               }
+           idx = idtmp[0];
            }
        else if(!strcmp(keyword,"c"))
-           counter =atoi(buf+4);
+           counter = atoi(buf+4);
        partial:
        if(!strcmp(keyword,"H") || part_test)
            {
@@ -243,6 +256,11 @@ static void pqgver(FILE *in, FILE *out)
                exit (1);
                }
            dsa = FIPS_dsa_new();
+           if (idx >= 0)
+               {
+               dsa->p = BN_dup(p);
+               dsa->q = BN_dup(q);
+               }
            if (!dsa2 && !dsa_builtin_paramgen(dsa, L, N, md,
                                        seed, seedlen, NULL,
                                        &counter2, &h2, NULL))
@@ -251,13 +269,20 @@ static void pqgver(FILE *in, FILE *out)
                        exit(1);
                        }
            if (dsa2 && dsa_builtin_paramgen2(dsa, L, N, md,
-                                       seed, seedlen, NULL,
+                                       seed, seedlen, idx, NULL,
                                        &counter2, &h2, NULL) < 0)
                        {
                        fprintf(stderr, "Parameter Generation error\n");
                        exit(1);
                        }
-            if (BN_cmp(dsa->p, p) || BN_cmp(dsa->q, q) || 
+           if (idx >= 0)
+               {
+               if (BN_cmp(dsa->g, g))
+                       fprintf(out, "Result = F\n");
+               else
+                       fprintf(out, "Result = P\n");
+               }
+            else if (BN_cmp(dsa->p, p) || BN_cmp(dsa->q, q) || 
                (!part_test &&
                ((BN_cmp(dsa->g, g) || (counter != counter2) || (h != h2)))))
                fprintf(out, "Result = F\n");
@@ -273,9 +298,11 @@ static void pqgver(FILE *in, FILE *out)
            dsa = NULL;
            if (part_test)
                {
-               fputs(buf,out);
+               if (idx == -1)
+                       fputs(buf,out);
                part_test = 0;
                }
+           idx = -1;
            }
        }
     }
@@ -436,7 +463,7 @@ static void keypair(FILE *in, FILE *out)
                        fprintf(stderr, "Parameter Generation error\n");
                        exit(1);
                        }
-           if (dsa2 && dsa_builtin_paramgen2(dsa, L, N, NULL, NULL, 0,
+           if (dsa2 && dsa_builtin_paramgen2(dsa, L, N, NULL, NULL, 0, -1,
                                                NULL, NULL, NULL, NULL) <= 0)
                        {
                        fprintf(stderr, "Parameter Generation error\n");
@@ -493,7 +520,7 @@ static void siggen(FILE *in, FILE *out)
                        fprintf(stderr, "Parameter Generation error\n");
                        exit(1);
                        }
-           if (dsa2 && dsa_builtin_paramgen2(dsa, L, N, md, NULL, 0,
+           if (dsa2 && dsa_builtin_paramgen2(dsa, L, N, md, NULL, 0, -1,
                                                NULL, NULL, NULL, NULL) <= 0)
                        {
                        fprintf(stderr, "Parameter Generation error\n");