Update mpi_gcd_invmod_odd() related comments/documentation
Signed-off-by: Felix Conway <felix.conway@arm.com>
diff --git a/library/bignum.c b/library/bignum.c
index 2f2ce6a..e141cda 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1764,7 +1764,7 @@
}
/* Check aliasing requirements */
- if (A == N || G == I || (I != NULL && (I == N || G == N))) {
+ if (A == N || (I != NULL && (I == N || G == N))) {
return MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
}
diff --git a/library/bignum_internal.h b/library/bignum_internal.h
index ee2220a..f3f6fcb 100644
--- a/library/bignum_internal.h
+++ b/library/bignum_internal.h
@@ -48,14 +48,14 @@
mbedtls_mpi *prec_RR);
/**
- * \brief Compute GCD(A, N) and/or A^-1 mod N if it exists,
- * in constant time.
+ * \brief A wrapper around a constant time function to compute
+ * GCD(A, N) and/or A^-1 mod N if it exists.
*
- * \warning Requires N to be odd, and 0 <= A <= N, and N > 1 if
- * I != NULL.
+ * \warning Requires N to be odd, and 0 <= A <= N. Additionally, if
+ * I != NULL, requires N > 1.
+ * The wrapper part of this function is not constant time.
*
- * \note G and I must not alias each other.
- * A and N must not alias each other.
+ * \note A and N must not alias each other.
* When I == NULL (computing only the GCD), G can alias A or N.
* When I != NULL (computing the modular inverse), G or I can
* alias A, but neither of them can alias N (the modulus).