Provide documentation for i2d_ECPrivateKey and d2i_ECPrivateKey

Reviewed-by: Emilia Käsper <emilia@openssl.org>

3 files changed, 79 insertions, 19 deletions

diff --git a/doc/crypto/EC_KEY_new.pod b/doc/crypto/EC_KEY_new.pod
index 2027569f44..e859689bcb 100644
--- a/doc/crypto/EC_KEY_new.pod
+++ b/doc/crypto/EC_KEY_new.pod
@@ -24,8 +24,6 @@ EC_KEY_new, EC_KEY_get_flags, EC_KEY_set_flags, EC_KEY_clear_flags, EC_KEY_new_b
  int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *prv);
  const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key);
  int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub);
- unsigned int EC_KEY_get_enc_flags(const EC_KEY *key);
- void EC_KEY_set_enc_flags(EC_KEY *eckey, unsigned int flags);
  point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key);
  void EC_KEY_set_conv_form(EC_KEY *eckey, point_conversion_form_t cform);
  void *EC_KEY_get_key_method_data(EC_KEY *key, 
@@ -69,16 +67,6 @@ on the key to confirm that it is valid.
 
 The functions EC_KEY_get0_group, EC_KEY_set_group, EC_KEY_get0_private_key, EC_KEY_set_private_key, EC_KEY_get0_public_key, and EC_KEY_set_public_key get and set the EC_GROUP object, the private key and the EC_POINT public key for the B<key> respectively.
 
-The functions EC_KEY_get_enc_flags and EC_KEY_set_enc_flags get and set the value of the encoding flags for the B<key>. There are two encoding
-flags currently defined - EC_PKEY_NO_PARAMETERS and EC_PKEY_NO_PUBKEY.  These flags define the behaviour of how the  B<key> is
-converted into ASN1 in a call to i2d_ECPrivateKey. If EC_PKEY_NO_PARAMETERS is set then the public parameters for the curve are not encoded
-along with the private key. If EC_PKEY_NO_PUBKEY is set then the public key is not encoded along with the private key.
-
-When reading a private key encoded with EC_PKEY_NO_PUBKEY,
-d2i_ECPrivateKey generates the missing public key
-automatically. Private keys encoded with EC_PKEY_NO_PARAMETERS cannot
-be loaded using d2i_ECPrivateKey.
-
 The functions EC_KEY_get_conv_form and EC_KEY_set_conv_form get and set the point_conversion_form for the B<key>. For a description
 of point_conversion_forms please refer to L<EC_POINT_new(3)|EC_POINT_new(3)>.
 
@@ -106,15 +94,15 @@ EC_KEY_get0_group returns the EC_GROUP associated with the EC_KEY.
 
 EC_KEY_get0_private_key returns the private key associated with the EC_KEY.
 
-EC_KEY_get_enc_flags returns the value of the current encoding flags for the EC_KEY.
-
 EC_KEY_get_conv_form return the point_conversion_form for the EC_KEY.
 
 
 =head1 SEE ALSO
 
-L<crypto(3)|crypto(3)>, L<ec(3)|ec(3)>, L<EC_GROUP_new(3)|EC_GROUP_new(3)>, L<EC_GROUP_copy(3)|EC_GROUP_copy(3)>,
-L<EC_POINT_new(3)|EC_POINT_new(3)>, L<EC_POINT_add(3)|EC_POINT_add(3)>,
-L<EC_GFp_simple_method(3)|EC_GFp_simple_method(3)>, L<d2i_ECPKParameters(3)|d2i_ECPKParameters(3)>
+L<crypto(3)|crypto(3)>, L<ec(3)|ec(3)>, L<EC_GROUP_new(3)|EC_GROUP_new(3)>,
+L<EC_GROUP_copy(3)|EC_GROUP_copy(3)>, L<EC_POINT_new(3)|EC_POINT_new(3)>,
+L<EC_POINT_add(3)|EC_POINT_add(3)>,
+L<EC_GFp_simple_method(3)|EC_GFp_simple_method(3)>,
+L<d2i_ECPKParameters(3)|d2i_ECPKParameters(3)>
 
 =cut
diff --git a/doc/crypto/EC_POINT_new.pod b/doc/crypto/EC_POINT_new.pod
index 69eb0d1a09..858baf4244 100644
--- a/doc/crypto/EC_POINT_new.pod
+++ b/doc/crypto/EC_POINT_new.pod
@@ -81,8 +81,13 @@ on the curve there will only ever be two possible values for y. Therefore a poin
 and EC_POINT_set_compressed_coordinates_GF2m functions where B<x> is the x co-ordinate and B<y_bit> is a value 0 or 1 to identify which of
 the two possible values for y should be used.
 
-In addition EC_POINTs can be converted to and from various external representations. Supported representations are octet strings, BIGNUMs and hexadecimal. The format of the external representation is described by the point_conversion_form. See L<EC_GROUP_copy(3)|EC_GROUP_copy(3)> for
-a description of point_conversion_form. Octet strings are stored in a buffer along with an associated buffer length. A point held in a BIGNUM is calculated by converting the point to an octet string and then converting that octet string into a BIGNUM integer. Points in hexadecimal format are stored in a NULL terminated character string where each character is one of the printable values 0-9 or A-F (or a-f).
+In addition EC_POINTs can be converted to and from various external
+representations. Supported representations are octet strings, BIGNUMs and
+hexadecimal. Octet strings are stored in a buffer along with an associated
+buffer length. A point held in a BIGNUM is calculated by converting the point to
+an octet string and then converting that octet string into a BIGNUM integer.
+Points in hexadecimal format are stored in a NULL terminated character string
+where each character is one of the printable values 0-9 or A-F (or a-f).
 
 The functions EC_POINT_point2oct, EC_POINT_oct2point, EC_POINT_point2bn, EC_POINT_bn2point, EC_POINT_point2hex and EC_POINT_hex2point convert
 from and to EC_POINTs for the formats: octet string, BIGNUM and hexadecimal respectively.
diff --git a/doc/crypto/d2i_ECPrivateKey.pod b/doc/crypto/d2i_ECPrivateKey.pod
new file mode 100644
index 0000000000..928c6fb78c
--- /dev/null
+++ b/doc/crypto/d2i_ECPrivateKey.pod
@@ -0,0 +1,67 @@
+=pod
+
+=head1 NAME
+
+i2d_ECPrivateKey, d2i_ECPrivate_key - Encode and decode functions for saving and
+reading EC_KEY structures
+
+=head1 SYNOPSIS
+
+ #include <openssl/ec.h>
+
+ EC_KEY *d2i_ECPrivateKey(EC_KEY **key, const unsigned char **in, long len);
+ int i2d_ECPrivateKey(EC_KEY *key, unsigned char **out);
+
+ unsigned int EC_KEY_get_enc_flags(const EC_KEY *key);
+ void EC_KEY_set_enc_flags(EC_KEY *eckey, unsigned int flags);
+
+=head1 DESCRIPTION
+
+The ECPrivateKey encode and decode routines encode and parse an
+B<EC_KEY> structure into a binary format (ASN.1 DER) and back again.
+
+These functions are similar to the d2i_X509() functions, and you should refer to
+that page for a detailed description (see L<d2i_X509(3)|d2i_X509(3)>).
+
+The format of the external representation of the public key written by
+i2d_ECPrivateKey (such as whether it is stored in a compressed form or not) is
+described by the point_conversion_form. See L<EC_GROUP_copy(3)|EC_GROUP_copy(3)>
+for a description of point_conversion_form.
+
+When reading a private key encoded without an associated public key (e.g. if
+EC_PKEY_NO_PUBKEY has been used - see below), then d2i_ECPrivateKey generates
+the missing public key automatically. Private keys encoded without parameters
+(e.g. if EC_PKEY_NO_PARAMETERS has been used - see below) then the key cannot be
+loaded using d2i_ECPrivateKey.
+
+The functions EC_KEY_get_enc_flags and EC_KEY_set_enc_flags get and set the
+value of the encoding flags for the B<key>. There are two encoding flags
+currently defined - EC_PKEY_NO_PARAMETERS and EC_PKEY_NO_PUBKEY.  These flags
+define the behaviour of how the  B<key> is converted into ASN1 in a call to
+i2d_ECPrivateKey. If EC_PKEY_NO_PARAMETERS is set then the public parameters for
+the curve are not encoded along with the private key. If EC_PKEY_NO_PUBKEY is
+set then the public key is not encoded along with the private key.
+
+=head1 RETURN VALUES
+
+d2i_ECPrivateKey() returns a valid B<EC_KEY> structure or B<NULL> if an error
+occurs. The error code that can be obtained by
+L<ERR_get_error(3)|ERR_get_error(3)>.
+
+i2d_ECPrivateKey() returns the number of bytes successfully encoded or a
+negative value if an error occurs. The error code can be obtained by
+L<ERR_get_error(3)|ERR_get_error(3)>.
+
+EC_KEY_get_enc_flags returns the value of the current encoding flags for the
+EC_KEY.
+
+=head1 SEE ALSO
+
+L<crypto(3)|crypto(3)>, L<ec(3)|ec(3)>, L<EC_GROUP_new(3)|EC_GROUP_new(3)>,
+L<EC_GROUP_copy(3)|EC_GROUP_copy(3)>, L<EC_POINT_new(3)|EC_POINT_new(3)>,
+L<EC_POINT_add(3)|EC_POINT_add(3)>,
+L<EC_GFp_simple_method(3)|EC_GFp_simple_method(3)>,
+L<d2i_ECPKParameters(3)|d2i_ECPKParameters(3)>,
+L<d2i_ECPrivateKey(3)|d2i_ECPrivateKey(3)>
+
+=cut