1evp(3)                              OpenSSL                             evp(3)
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NAME

6       evp - high-level cryptographic functions
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SYNOPSIS

9        #include <openssl/evp.h>
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DESCRIPTION

12       The EVP library provides a high-level interface to cryptographic
13       functions.
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15       EVP_Seal... and EVP_Open... provide public key encryption and
16       decryption to implement digital "envelopes".
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18       The EVP_Sign... and EVP_Verify... functions implement digital
19       signatures.
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21       Symmetric encryption is available with the EVP_Encrypt...  functions.
22       The EVP_Digest... functions provide message digests.
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24       The EVP_PKEY... functions provide a high level interface to asymmetric
25       algorithms.
26
27       Algorithms are loaded with OpenSSL_add_all_algorithms(3).
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29       All the symmetric algorithms (ciphers), digests and asymmetric
30       algorithms (public key algorithms) can be replaced by ENGINE modules
31       providing alternative implementations. If ENGINE implementations of
32       ciphers or digests are registered as defaults, then the various EVP
33       functions will automatically use those implementations automatically in
34       preference to built in software implementations. For more information,
35       consult the engine(3) man page.
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37       Although low level algorithm specific functions exist for many
38       algorithms their use is discouraged. They cannot be used with an ENGINE
39       and ENGINE versions of new algorithms cannot be accessed using the low
40       level functions.  Also makes code harder to adapt to new algorithms and
41       some options are not cleanly supported at the low level and some
42       operations are more efficient using the high level interface.
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SEE ALSO

45       EVP_DigestInit(3), EVP_EncryptInit(3), EVP_OpenInit(3),
46       EVP_SealInit(3), EVP_SignInit(3), EVP_VerifyInit(3),
47       OpenSSL_add_all_algorithms(3), engine(3)
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511.0.0e                            2006-07-08                            evp(3)