Add thirdparty libs

thirdparty/openssl/doc/crypto/evp.pod

@@ -0,0 +1,60 @@
+=pod
+
+=head1 NAME
+
+evp - high-level cryptographic functions
+
+=head1 SYNOPSIS
+
+ #include <openssl/evp.h>
+
+=head1 DESCRIPTION
+
+The EVP library provides a high-level interface to cryptographic
+functions.
+
+B<EVP_Seal>I<...> and B<EVP_Open>I<...> provide public key encryption
+and decryption to implement digital "envelopes".
+
+The B<EVP_Sign>I<...> and B<EVP_Verify>I<...> functions implement
+digital signatures.
+
+Symmetric encryption is available with the B<EVP_Encrypt>I<...>
+functions.  The B<EVP_Digest>I<...> functions provide message digests.
+
+The B<EVP_PKEY>I<...> functions provide a high level interface to
+asymmetric algorithms.
+
+The L<B<EVP_Encode>I<...>|EVP_EncodeInit(3)> and
+L<B<EVP_Decode>I<...>|EVP_EncodeInit(3)> functions implement base 64 encoding
+and decoding.
+
+Algorithms are loaded with OpenSSL_add_all_algorithms(3).
+
+All the symmetric algorithms (ciphers), digests and asymmetric algorithms
+(public key algorithms) can be replaced by ENGINE modules providing alternative
+implementations. If ENGINE implementations of ciphers or digests are registered
+as defaults, then the various EVP functions will automatically use those
+implementations automatically in preference to built in software
+implementations. For more information, consult the engine(3) man page.
+
+Although low level algorithm specific functions exist for many algorithms
+their use is discouraged. They cannot be used with an ENGINE and ENGINE
+versions of new algorithms cannot be accessed using the low level functions.
+Also makes code harder to adapt to new algorithms and some options are not 
+cleanly supported at the low level and some operations are more efficient
+using the high level interface.
+
+=head1 SEE ALSO
+
+L<EVP_DigestInit(3)|EVP_DigestInit(3)>,
+L<EVP_EncryptInit(3)|EVP_EncryptInit(3)>,
+L<EVP_OpenInit(3)|EVP_OpenInit(3)>,
+L<EVP_SealInit(3)|EVP_SealInit(3)>,
+L<EVP_SignInit(3)|EVP_SignInit(3)>,
+L<EVP_VerifyInit(3)|EVP_VerifyInit(3)>,
+L<EVP_EncodeInit(3)>,
+L<OpenSSL_add_all_algorithms(3)|OpenSSL_add_all_algorithms(3)>,
+L<engine(3)|engine(3)>
+
+=cut