Automatically generated by Pod::Man 4.07 (Pod::Simple 3.32) Standard preamble: ========================================================================
NAMEevp - high-level cryptographic functions
EVP_Seal... and EVP_Open... provide public key encryption and decryption to implement digital ``envelopes''.
The EVP_DigestSign... and EVP_DigestVerify... functions implement digital signatures and Message Authentication Codes (MACs). Also see the older EVP_Sign... and EVP_Verify... functions.
Symmetric encryption is available with the EVP_Encrypt... functions. The EVP_Digest... functions provide message digests.
- For key agreement see EVP_PKEY_derive(3)
- For signing and verifying see EVP_PKEY_sign(3), EVP_PKEY_verify(3) and EVP_PKEY_verify_recover(3). However, note that these functions do not perform a digest of the data to be signed. Therefore normally you would use the EVP_DigestSign... functions for this purpose.
- For encryption and decryption see EVP_PKEY_encrypt(3) and EVP_PKEY_decrypt(3) respectively. However, note that these functions perform encryption and decryption only. As public key encryption is an expensive operation, normally you would wrap an encrypted message in a digital envelope using the EVP_Seal... and EVP_Open... functions.
The EVP_BytesToKey(3) function provides some limited support for password based encryption. Careful selection of the parameters will provide a PKCS#5
Algorithms are loaded with OpenSSL_add_all_algorithms(3).
The EVP_Encode... and EVP_Decode... functions implement base 64 encoding and decoding.
All the symmetric algorithms (ciphers), digests and asymmetric algorithms (public key algorithms) can be replaced by
Although low level algorithm specific functions exist for many algorithms their use is discouraged. They cannot be used with an