diff options
Diffstat (limited to 'crypto/dsa/dsa_gen.c')
-rw-r--r-- | crypto/dsa/dsa_gen.c | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c index d686ab0af770..5a328aaab5b4 100644 --- a/crypto/dsa/dsa_gen.c +++ b/crypto/dsa/dsa_gen.c @@ -86,6 +86,8 @@ # include "dsa_locl.h" # ifdef OPENSSL_FIPS +/* Workaround bug in prototype */ +# define fips_dsa_builtin_paramgen2 fips_dsa_paramgen_bad # include <openssl/fips.h> # endif @@ -383,4 +385,371 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits, BN_MONT_CTX_free(mont); return ok; } + +# ifdef OPENSSL_FIPS +# undef fips_dsa_builtin_paramgen2 +extern int fips_dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N, + const EVP_MD *evpmd, + const unsigned char *seed_in, + size_t seed_len, int idx, + unsigned char *seed_out, + int *counter_ret, unsigned long *h_ret, + BN_GENCB *cb); +# endif + +/* + * This is a parameter generation algorithm for the DSA2 algorithm as + * described in FIPS 186-3. + */ + +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, int idx, unsigned char *seed_out, + int *counter_ret, unsigned long *h_ret, + BN_GENCB *cb) +{ + int ok = -1; + unsigned char *seed = NULL, *seed_tmp = NULL; + unsigned char md[EVP_MAX_MD_SIZE]; + int mdsize; + BIGNUM *r0, *W, *X, *c, *test; + BIGNUM *g = NULL, *q = NULL, *p = NULL; + BN_MONT_CTX *mont = NULL; + int i, k, n = 0, m = 0, qsize = N >> 3; + int counter = 0; + int r = 0; + BN_CTX *ctx = NULL; + EVP_MD_CTX mctx; + unsigned int h = 2; + +# ifdef OPENSSL_FIPS + + if (FIPS_mode()) + return fips_dsa_builtin_paramgen2(ret, L, N, evpmd, + seed_in, seed_len, idx, + seed_out, counter_ret, h_ret, cb); +# endif + + EVP_MD_CTX_init(&mctx); + + if (evpmd == NULL) { + if (N == 160) + evpmd = EVP_sha1(); + else if (N == 224) + evpmd = EVP_sha224(); + else + evpmd = EVP_sha256(); + } + + mdsize = 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_out) + seed_tmp = seed_out; + else + seed_tmp = OPENSSL_malloc(seed_len); + + if (!seed || !seed_tmp) + goto err; + + if (seed_in) + memcpy(seed, seed_in, seed_len); + + } + + if ((ctx = BN_CTX_new()) == NULL) + goto err; + + if ((mont = BN_MONT_CTX_new()) == NULL) + goto err; + + BN_CTX_start(ctx); + r0 = BN_CTX_get(ctx); + g = BN_CTX_get(ctx); + W = BN_CTX_get(ctx); + X = BN_CTX_get(ctx); + c = 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 (;;) { + for (;;) { /* find q */ + unsigned char *pmd; + /* step 1 */ + if (!BN_GENCB_call(cb, 0, m++)) + goto err; + + if (!seed_in) { + if (RAND_pseudo_bytes(seed, seed_len) < 0) + goto err; + } + /* step 2 */ + if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL)) + goto err; + /* Take least significant bits of md */ + if (mdsize > qsize) + pmd = md + mdsize - qsize; + else + pmd = md; + + if (mdsize < qsize) + memset(md + mdsize, 0, qsize - mdsize); + + /* step 3 */ + pmd[0] |= 0x80; + pmd[qsize - 1] |= 0x01; + if (!BN_bin2bn(pmd, qsize, q)) + goto err; + + /* step 4 */ + r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx, + seed_in ? 1 : 0, cb); + if (r > 0) + break; + if (r != 0) + goto err; + /* Provided seed didn't produce a prime: error */ + if (seed_in) { + ok = 0; + DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_Q_NOT_PRIME); + goto err; + } + + /* do a callback call */ + /* step 5 */ + } + /* Copy seed to seed_out before we mess with it */ + if (seed_out) + memcpy(seed_out, seed, seed_len); + + if (!BN_GENCB_call(cb, 2, 0)) + goto err; + if (!BN_GENCB_call(cb, 3, 0)) + goto err; + + /* step 6 */ + counter = 0; + /* "offset = 1" */ + + n = (L - 1) / (mdsize << 3); + + for (;;) { + if ((counter != 0) && !BN_GENCB_call(cb, 0, counter)) + goto err; + + /* step 7 */ + BN_zero(W); + /* now 'buf' contains "SEED + offset - 1" */ + for (k = 0; k <= n; k++) { + /* + * obtain "SEED + offset + k" by incrementing: + */ + for (i = seed_len - 1; i >= 0; i--) { + seed[i]++; + if (seed[i] != 0) + break; + } + + if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL)) + goto err; + + /* step 8 */ + if (!BN_bin2bn(md, mdsize, r0)) + goto err; + if (!BN_lshift(r0, r0, (mdsize << 3) * k)) + goto err; + if (!BN_add(W, W, r0)) + goto err; + } + + /* more of step 8 */ + if (!BN_mask_bits(W, L - 1)) + goto err; + if (!BN_copy(X, W)) + goto err; + if (!BN_add(X, X, test)) + goto err; + + /* step 9 */ + if (!BN_lshift1(r0, q)) + goto err; + if (!BN_mod(c, X, r0, ctx)) + goto err; + if (!BN_sub(r0, c, BN_value_one())) + goto err; + if (!BN_sub(p, X, r0)) + goto err; + + /* step 10 */ + if (BN_cmp(p, test) >= 0) { + /* step 11 */ + r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb); + if (r > 0) + goto end; /* found it */ + if (r != 0) + goto err; + } + + /* step 13 */ + counter++; + /* "offset = offset + n + 1" */ + + /* step 14 */ + 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 (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 (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)) + goto err; + + ok = 1; + err: + if (ok == 1) { + 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->g = BN_dup(g); + if (ret->p == NULL || ret->q == NULL || ret->g == NULL) { + ok = -1; + goto err; + } + if (counter_ret != NULL) + *counter_ret = counter; + if (h_ret != NULL) + *h_ret = h; + } + 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 |