diff options
author | Dr. Stephen Henson <steve@openssl.org> | 2000-03-08 01:48:12 +0000 |
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committer | Dr. Stephen Henson <steve@openssl.org> | 2000-03-08 01:48:12 +0000 |
commit | 9886f420145883100ada06a1184eff195a133b39 (patch) | |
tree | a901bbc083d6024dbfbd98695682cbfd8dd12525 | |
parent | b7e1636171e31391416f0b0e4b3f5dcdc764da2a (diff) |
Manual pages for EVP_Open* and EVP_Seal*
-rw-r--r-- | doc/crypto/EVP_OpenInit.pod | 51 | ||||
-rw-r--r-- | doc/crypto/EVP_SealInit.pod | 70 |
2 files changed, 121 insertions, 0 deletions
diff --git a/doc/crypto/EVP_OpenInit.pod b/doc/crypto/EVP_OpenInit.pod new file mode 100644 index 0000000000..9707a4b399 --- /dev/null +++ b/doc/crypto/EVP_OpenInit.pod @@ -0,0 +1,51 @@ +=pod + +=head1 NAME + +EVP_OpenInit, EVP_OpenUpdate, EVP_OpenFinal - EVP envelope decryption + +=head1 SYNOPSIS + + #include <openssl/evp.h> + + int EVP_OpenInit(EVP_CIPHER_CTX *ctx,EVP_CIPHER *type,unsigned char *ek, + int ekl,unsigned char *iv,EVP_PKEY *priv); + void EVP_OpenUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, + int *outl, unsigned char *in, int inl); + void EVP_OpenFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, + int *outl); + +=head1 DESCRIPTION + +The EVP envelope routines are a high level interface to envelope +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 +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. + +EVP_OpenUpdate() and EVP_OpenFinal() have exactly the same properties +as the EVP_DecryptUpdate() and EVP_DecryptFinal() routines, as +documented on the L<EVP_EncryptInit(3)|EVP_EncryptInit(3)> manual +page. + +=head1 RETURN VALUES + +EVP_OpenInit() returns -1 on error or an non zero integer (actually the +recovered secret key size) if successful. + +EVP_SealUpdate() does not return a value. + +EVP_SealFinal() returns 0 if the decrypt failed or 1 for success. + +=head1 SEE ALSO + +L<evp(3)|evp(3)>,L<rand(3)|rand(3)> +L<EVP_EncryptInit(3)|EVP_EncryptInit(3)>, +L<EVP_SealInit(3)|EVP_SealInit(3)> + +=head1 HISTORY + +=cut diff --git a/doc/crypto/EVP_SealInit.pod b/doc/crypto/EVP_SealInit.pod new file mode 100644 index 0000000000..1579d110fa --- /dev/null +++ b/doc/crypto/EVP_SealInit.pod @@ -0,0 +1,70 @@ +=pod + +=head1 NAME + +EVP_SealInit, EVP_SealUpdate, EVP_SealFinal - EVP envelope encryption + +=head1 SYNOPSIS + + #include <openssl/evp.h> + + int EVP_SealInit(EVP_CIPHER_CTX *ctx, EVP_CIPHER *type, unsigned char **ek, + int *ekl, unsigned char *iv,EVP_PKEY **pubk, int npubk); + void EVP_SealUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, + int *outl, unsigned char *in, int inl); + void EVP_SealFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, + int *outl); + +=head1 DESCRIPTION + +The EVP envelope routines are a high level interface to envelope +encryption. They generate a random key and then "envelope" it by +using public key encryption. Data can then be encrypted using this +key. + +EVP_SealInit() initialises 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 +keys, this allows the same encrypted data to be decrypted using any +of the corresponding private keys. B<ek> is an array of buffers where +the public key encrypted secret key will be written, each buffer must +contain enough room for the corresponding encrypted key: that is +B<ek[i]> must have room for B<EVP_PKEY_size(pubk[i])> bytes. The actual +size of each encrypted secret key is written to the array B<ekl>. B<pubk> is +an array of B<npubk> public keys. + +EVP_SealUpdate() and EVP_SealFinal() have exactly the same properties +as the EVP_EncryptUpdate() and EVP_EncryptFinal() routines, as +documented on the L<EVP_EncryptInit(3)|EVP_EncryptInit(3)> manual +page. + +=head1 RETURN VALUES + +EVP_SealInit() returns -1 on error or B<npubk> if successful. + +EVP_SealUpdate() and EVP_SealFinal() do not return values. + +=head1 NOTES + +Because a random secret key is generated the random number generator +must be seeded before calling EVP_SealInit(). + +The public key must be RSA because it is the only OpenSSL public key +algorithm that supports key transport. + +Envelope encryption is the usual method of using public key encryption +on large amounts of data, this is because public key encryption is slow +but symmetric encryption is fast. So symmetric encryption is used for +bulk encryption and the small random symmetric key used is transferred +using public key encryption. + +=head1 SEE ALSO + +L<evp(3)|evp(3)>,L<rand(3)|rand(3)> +L<EVP_EncryptInit(3)|EVP_EncryptInit(3)>, +L<EVP_OpenInit(3)|EVP_OpenInit(3)> + +=head1 HISTORY + +=cut |