/* Nr := round(2^i / N) */
if (i != recp->shift)
- recp->shift=BN_reciprocal(&(recp->Nr),&(recp->N),
- i,ctx); /* BN_reciprocal returns i, or -1 for an error */
+ recp->shift=BN_reciprocal(&(recp->Nr),&(recp->N),i,ctx);
+ /* BN_reciprocal could have returned -1 for an error */
if (recp->shift == -1) goto err;
- /*-
- * d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))|
- * = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))|
- * <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)|
- * = |m/N|
- */
+ /*-
+ * d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))|
+ * = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))|
+ * <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)|
+ * = |m/N|
+ */
if (!BN_rshift(a,m,recp->num_bits)) goto err;
if (!BN_mul(b,a,&(recp->Nr),ctx)) goto err;
if (!BN_rshift(d,b,i-recp->num_bits)) goto err;