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Correct argument order for CMS_decrypt() in docs.
[oweals/openssl.git]
/
doc
/
crypto
/
BN_mod_mul_montgomery.pod
diff --git
a/doc/crypto/BN_mod_mul_montgomery.pod
b/doc/crypto/BN_mod_mul_montgomery.pod
index 825a29f979f0b7ea095dd4247f719ec5cc5b1615..6b16351b92e4bd67967762e3f0de7858c5a620e8 100644
(file)
--- a/
doc/crypto/BN_mod_mul_montgomery.pod
+++ b/
doc/crypto/BN_mod_mul_montgomery.pod
@@
-29,41
+29,42
@@
BN_from_montgomery, BN_to_montgomery - Montgomery multiplication
=head1 DESCRIPTION
These functions implement Montgomery multiplication. They are used
=head1 DESCRIPTION
These functions implement Montgomery multiplication. They are used
-automatically when
BN_mod_exp(3)
is called with suitable input,
+automatically when
L<BN_mod_exp(3)|BN_mod_exp(3)>
is called with suitable input,
but they may be useful when several operations are to be performed
using the same modulus.
BN_MONT_CTX_new() allocates and initializes a B<BN_MONT_CTX> structure.
BN_MONT_CTX_init() initializes an existing uninitialized B<BN_MONT_CTX>.
but they may be useful when several operations are to be performed
using the same modulus.
BN_MONT_CTX_new() allocates and initializes a B<BN_MONT_CTX> structure.
BN_MONT_CTX_init() initializes an existing uninitialized B<BN_MONT_CTX>.
-BN_MONT_CTX_set() sets up the
B<mont> structure from the modulus B
<m>
+BN_MONT_CTX_set() sets up the
I<mont> structure from the modulus I
<m>
by precomputing its inverse and a value R.
by precomputing its inverse and a value R.
-BN_MONT_CTX_copy() copies the B<
N_MONT_CTX> B<from> to B
<to>.
+BN_MONT_CTX_copy() copies the B<
BN_MONT_CTX> I<from> to I
<to>.
BN_MONT_CTX_free() frees the components of the B<BN_MONT_CTX>, and, if
it was created by BN_MONT_CTX_new(), also the structure itself.
BN_MONT_CTX_free() frees the components of the B<BN_MONT_CTX>, and, if
it was created by BN_MONT_CTX_new(), also the structure itself.
-BN_mod_mul_montgomery() computes Mont(
B<a>,B<b>):=B<a>*B
<b>*R^-1 and places
-the result in
B
<r>.
+BN_mod_mul_montgomery() computes Mont(
I<a>,I<b>):=I<a>*I
<b>*R^-1 and places
+the result in
I
<r>.
-BN_from_montgomery() performs the Montgomery reduction
B<r> = B
<a>*R^-1.
+BN_from_montgomery() performs the Montgomery reduction
I<r> = I
<a>*R^-1.
-BN_to_montgomery() computes Mont(B<a>,R^2).
+BN_to_montgomery() computes Mont(I<a>,R^2), i.e. I<a>*R.
+Note that I<a> must be non-negative and smaller than the modulus.
-For all functions,
B
<ctx> is a previously allocated B<BN_CTX> used for
+For all functions,
I
<ctx> is a previously allocated B<BN_CTX> used for
temporary variables.
The B<BN_MONT_CTX> structure is defined as follows:
typedef struct bn_mont_ctx_st
{
temporary variables.
The B<BN_MONT_CTX> structure is defined as follows:
typedef struct bn_mont_ctx_st
{
- int use_word; /* 0 for word form, 1 for bignum form */
int ri; /* number of bits in R */
BIGNUM RR; /* R^2 (used to convert to Montgomery form) */
BIGNUM N; /* The modulus */
int ri; /* number of bits in R */
BIGNUM RR; /* R^2 (used to convert to Montgomery form) */
BIGNUM N; /* The modulus */
- BIGNUM Ni; /* The inverse of N (bignum form) */
- BN_ULONG n0; /* The inverse of N in word form */
+ BIGNUM Ni; /* R*(1/R mod N) - N*Ni = 1
+ * (Ni is only stored for bignum algorithm) */
+ BN_ULONG n0; /* least significant word of Ni */
int flags;
} BN_MONT_CTX;
int flags;
} BN_MONT_CTX;
@@
-77,11
+78,17
@@
on error.
BN_MONT_CTX_init() and BN_MONT_CTX_free() have no return values.
For the other functions, 1 is returned for success, 0 on error.
BN_MONT_CTX_init() and BN_MONT_CTX_free() have no return values.
For the other functions, 1 is returned for success, 0 on error.
-The error codes can be obtained by ERR_get_error(3).
+The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>.
+
+=head1 WARNING
+
+The inputs must be reduced modulo B<m>, otherwise the result will be
+outside the expected range.
=head1 SEE ALSO
=head1 SEE ALSO
-bn(3), err(3), BN_add(3), BN_CTX_new(3)
+L<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<BN_add(3)|BN_add(3)>,
+L<BN_CTX_new(3)|BN_CTX_new(3)>
=head1 HISTORY
=head1 HISTORY