diff options
Diffstat (limited to 'openssl/crypto/bn/bn_gf2m.c')
| -rw-r--r-- | openssl/crypto/bn/bn_gf2m.c | 111 |
1 files changed, 93 insertions, 18 deletions
diff --git a/openssl/crypto/bn/bn_gf2m.c b/openssl/crypto/bn/bn_gf2m.c index 432a3aa33..08ab9fd22 100644 --- a/openssl/crypto/bn/bn_gf2m.c +++ b/openssl/crypto/bn/bn_gf2m.c @@ -94,6 +94,8 @@ #include "cryptlib.h" #include "bn_lcl.h" +#ifndef OPENSSL_NO_EC2M + /* Maximum number of iterations before BN_GF2m_mod_solve_quad_arr should fail. */ #define MAX_ITERATIONS 50 @@ -122,6 +124,7 @@ static const BN_ULONG SQR_tb[16] = SQR_tb[(w) >> 4 & 0xF] << 8 | SQR_tb[(w) & 0xF] #endif +#if !defined(OPENSSL_BN_ASM_GF2m) /* Product of two polynomials a, b each with degree < BN_BITS2 - 1, * result is a polynomial r with degree < 2 * BN_BITS - 1 * The caller MUST ensure that the variables have the right amount @@ -216,7 +219,9 @@ static void bn_GF2m_mul_2x2(BN_ULONG *r, const BN_ULONG a1, const BN_ULONG a0, c r[2] ^= m1 ^ r[1] ^ r[3]; /* h0 ^= m1 ^ l1 ^ h1; */ r[1] = r[3] ^ r[2] ^ r[0] ^ m1 ^ m0; /* l1 ^= l0 ^ h0 ^ m0; */ } - +#else +void bn_GF2m_mul_2x2(BN_ULONG *r, BN_ULONG a1, BN_ULONG a0, BN_ULONG b1, BN_ULONG b0); +#endif /* Add polynomials a and b and store result in r; r could be a or b, a and b * could be equal; r is the bitwise XOR of a and b. @@ -360,21 +365,17 @@ int BN_GF2m_mod_arr(BIGNUM *r, const BIGNUM *a, const int p[]) int BN_GF2m_mod(BIGNUM *r, const BIGNUM *a, const BIGNUM *p) { int ret = 0; - const int max = BN_num_bits(p) + 1; - int *arr=NULL; + int arr[6]; bn_check_top(a); bn_check_top(p); - if ((arr = (int *)OPENSSL_malloc(sizeof(int) * max)) == NULL) goto err; - ret = BN_GF2m_poly2arr(p, arr, max); - if (!ret || ret > max) + ret = BN_GF2m_poly2arr(p, arr, sizeof(arr)/sizeof(arr[0])); + if (!ret || ret > (int)(sizeof(arr)/sizeof(arr[0]))) { BNerr(BN_F_BN_GF2M_MOD,BN_R_INVALID_LENGTH); - goto err; + return 0; } ret = BN_GF2m_mod_arr(r, a, arr); bn_check_top(r); -err: - if (arr) OPENSSL_free(arr); return ret; } @@ -521,7 +522,7 @@ err: */ int BN_GF2m_mod_inv(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx) { - BIGNUM *b, *c, *u, *v, *tmp; + BIGNUM *b, *c = NULL, *u = NULL, *v = NULL, *tmp; int ret = 0; bn_check_top(a); @@ -529,18 +530,18 @@ int BN_GF2m_mod_inv(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx) BN_CTX_start(ctx); - b = BN_CTX_get(ctx); - c = BN_CTX_get(ctx); - u = BN_CTX_get(ctx); - v = BN_CTX_get(ctx); - if (v == NULL) goto err; + if ((b = BN_CTX_get(ctx))==NULL) goto err; + if ((c = BN_CTX_get(ctx))==NULL) goto err; + if ((u = BN_CTX_get(ctx))==NULL) goto err; + if ((v = BN_CTX_get(ctx))==NULL) goto err; - if (!BN_one(b)) goto err; if (!BN_GF2m_mod(u, a, p)) goto err; - if (!BN_copy(v, p)) goto err; - if (BN_is_zero(u)) goto err; + if (!BN_copy(v, p)) goto err; +#if 0 + if (!BN_one(b)) goto err; + while (1) { while (!BN_is_odd(u)) @@ -565,13 +566,86 @@ int BN_GF2m_mod_inv(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx) if (!BN_GF2m_add(u, u, v)) goto err; if (!BN_GF2m_add(b, b, c)) goto err; } +#else + { + int i, ubits = BN_num_bits(u), + vbits = BN_num_bits(v), /* v is copy of p */ + top = p->top; + BN_ULONG *udp,*bdp,*vdp,*cdp; + + bn_wexpand(u,top); udp = u->d; + for (i=u->top;i<top;i++) udp[i] = 0; + u->top = top; + bn_wexpand(b,top); bdp = b->d; + bdp[0] = 1; + for (i=1;i<top;i++) bdp[i] = 0; + b->top = top; + bn_wexpand(c,top); cdp = c->d; + for (i=0;i<top;i++) cdp[i] = 0; + c->top = top; + vdp = v->d; /* It pays off to "cache" *->d pointers, because + * it allows optimizer to be more aggressive. + * But we don't have to "cache" p->d, because *p + * is declared 'const'... */ + while (1) + { + while (ubits && !(udp[0]&1)) + { + BN_ULONG u0,u1,b0,b1,mask; + u0 = udp[0]; + b0 = bdp[0]; + mask = (BN_ULONG)0-(b0&1); + b0 ^= p->d[0]&mask; + for (i=0;i<top-1;i++) + { + u1 = udp[i+1]; + udp[i] = ((u0>>1)|(u1<<(BN_BITS2-1)))&BN_MASK2; + u0 = u1; + b1 = bdp[i+1]^(p->d[i+1]&mask); + bdp[i] = ((b0>>1)|(b1<<(BN_BITS2-1)))&BN_MASK2; + b0 = b1; + } + udp[i] = u0>>1; + bdp[i] = b0>>1; + ubits--; + } + + if (ubits<=BN_BITS2 && udp[0]==1) break; + + if (ubits<vbits) + { + i = ubits; ubits = vbits; vbits = i; + tmp = u; u = v; v = tmp; + tmp = b; b = c; c = tmp; + udp = vdp; vdp = v->d; + bdp = cdp; cdp = c->d; + } + for(i=0;i<top;i++) + { + udp[i] ^= vdp[i]; + bdp[i] ^= cdp[i]; + } + if (ubits==vbits) + { + bn_correct_top(u); + ubits = BN_num_bits(u); + } + } + bn_correct_top(b); + } +#endif if (!BN_copy(r, b)) goto err; bn_check_top(r); ret = 1; err: +#ifdef BN_DEBUG /* BN_CTX_end would complain about the expanded form */ + bn_correct_top(c); + bn_correct_top(u); + bn_correct_top(v); +#endif BN_CTX_end(ctx); return ret; } @@ -1033,3 +1107,4 @@ int BN_GF2m_arr2poly(const int p[], BIGNUM *a) return 1; } +#endif |