ispell.

The EVP digest routines are a high level interface to message digests.

EVP_DigestInit() initialises a digest context B<ctx> to use a digest

EVP_DigestInit() initializes a digest context B<ctx> to use a digest

B<type>: this will typically be supplied by a function such as

EVP_sha1().

EVP_DigestUpdate() hashes B<cnt> bytes of data at B<d> into the

digest context B<ctx>. This funtion can be called several times on the

digest context B<ctx>. This function can be called several times on the

same B<ctx> to hash additional data.

EVP_DigestFinal() retrieves the digest value from B<ctx> and places

bytes of data written (i.e. the length of the digest) will be written

to the integer at B<s>, at most B<EVP_MAX_MD_SIZE> bytes will be written.

After calling EVP_DigestFinal() no additional calls to EVP_DigestUpdate()

can be made, but EVP_DigestInit() can be called to initialiase a new

can be made, but EVP_DigestInit() can be called to initialize a new

digest operation.

EVP_MD_CTX_copy() can be used to copy the message digest state from

EVP_get_digestbyname(), EVP_get_digestbynid() and EVP_get_digestbyobj()

return an B<EVP_MD> structure when passed a digest name, a digest NID or

an ASN1_OBJECT structure respectively. The digest table must be initialised

an ASN1_OBJECT structure respectively. The digest table must be initialized

using, for example, OpenSSL_add_all_digests() for these functions to work.

=head1 RETURN VALUES

The EVP cipher routines are a high level interface to certain

symmetric ciphers.

EVP_EncryptInit() initialises a cipher context B<ctx> for encryption

EVP_EncryptInit() initializes a cipher context B<ctx> for encryption

with cipher B<type>. B<type> is normally supplied by a function such

as EVP_des_cbc() . B<key> is the symmetric key to use and B<iv> is the

IV to use (if necessary), the actual number of bytes used for the

=item EVP_idea_cbc() EVP_idea_ecb(void), EVP_idea_cfb(void), EVP_idea_ofb(void), EVP_idea_cbc(void)

IDES encryption algorothm in CBC, ECB, CFB and OFB modes respectively.

IDEA encryption algorithm in CBC, ECB, CFB and OFB modes respectively.

=item EVP_rc2_cbc(void), EVP_rc2_ecb(void), EVP_rc2_cfb(void), EVP_rc2_ofb(void)

unpredictable. This is because it has become standard practice to define a 

generic key as a fixed unsigned char array containing EVP_MAX_KEY_LENGTH bytes.

The ASN1 code is incomplete (and sometimes innacurate) it has only been tested

The ASN1 code is incomplete (and sometimes inaccurate) it has only been tested

for certain common S/MIME ciphers (RC2, DES, triple DES) in CBC mode.

=head1 EXAMPLES

decryption. They decrypt a public key encrypted symmetric key and

then decrypt data using it.

EVP_OpenInit() initialises a cipher context B<ctx> for decryption

EVP_OpenInit() initializes a cipher context B<ctx> for decryption

with cipher B<type>. It decrypts the encrypted symmetric key of length

B<ekl> bytes passed in the B<ek> parameter using the private key B<priv>.

The IV is supplied in the B<iv> parameter.

It is possible to call EVP_OpenInit() twice in the same way as

EVP_DecryptInit(). The first call should have B<priv> set to NULL

and (after setting any cipher paramaters) it should be called again

and (after setting any cipher parameters) it should be called again

with B<type> set to NULL.

If the cipher passed in the B<type> parameter is a variable length

using public key encryption. Data can then be encrypted using this

key.

EVP_SealInit() initialises a cipher context B<ctx> for encryption

EVP_SealInit() initializes a cipher context B<ctx> for encryption

with cipher B<type> using a random secret key and IV supplied in

the B<iv> parameter. B<type> is normally supplied by a function such

as EVP_des_cbc(). The secret key is encrypted using one or more public

It is possible to call EVP_SealInit() twice in the same way as

EVP_EncryptInit(). The first call should have B<npubk> set to 0

and (after setting any cipher paramaters) it should be called again

and (after setting any cipher parameters) it should be called again

with B<type> set to NULL.

=head1 SEE ALSO

The EVP signature routines are a high level interface to digital

signatures.

EVP_SignInit() initialises a signing context B<ctx> to using digest

EVP_SignInit() initializes a signing context B<ctx> to using digest

B<type>: this will typically be supplied by a function such as

EVP_sha1().

EVP_SignUpdate() hashes B<cnt> bytes of data at B<d> into the

signature context B<ctx>. This funtion can be called several times on the

signature context B<ctx>. This function can be called several times on the

same B<ctx> to include additional data.

EVP_SignFinal() signs the data in B<ctx> using the private key B<pkey>

then the number of bytes of data written (i.e. the length of the signature)

will be written to the integer at B<s>, at most EVP_PKEY_size(pkey) bytes

will be written.  After calling EVP_SignFinal() no additional calls to

EVP_SignUpdate() can be made, but EVP_SignInit() can be called to initialiase

EVP_SignUpdate() can be made, but EVP_SignInit() can be called to initialize

a new signature operation.

EVP_PKEY_size() returns the maximum size of a signature in bytes. The actual