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Update docs.
This commit is contained in:
Dr. Stephen Henson
parent
581f1c8494
commit
3811eed8d5
@ -2,40 +2,61 @@
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=head1 NAME
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EVP_EncryptInit, EVP_EncryptUpdate, EVP_EncryptFinal, EVP_DecryptInit,
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EVP_DecryptUpdate, EVP_DecryptFinal, EVP_CipherInit, EVP_CipherUpdate,
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EVP_CipherFinal, EVP_CIPHER_CTX_set_key_length, EVP_CIPHER_CTX_ctrl,
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EVP_CIPHER_CTX_cleanup, EVP_get_cipherbyname, EVP_get_cipherbynid,
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EVP_get_cipherbyobj, EVP_CIPHER_nid, EVP_CIPHER_block_size,
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EVP_CIPHER_key_length, EVP_CIPHER_iv_length, EVP_CIPHER_flags,
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EVP_CIPHER_mode, EVP_CIPHER_type, EVP_CIPHER_CTX_cipher, EVP_CIPHER_CTX_nid,
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EVP_CIPHER_CTX_block_size, EVP_CIPHER_CTX_key_length, EVP_CIPHER_CTX_iv_length,
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EVP_CIPHER_CTX_get_app_data, EVP_CIPHER_CTX_set_app_data, EVP_CIPHER_CTX_type,
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EVP_CIPHER_CTX_flags, EVP_CIPHER_CTX_mode, EVP_CIPHER_param_to_asn1,
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EVP_CIPHER_asn1_to_param, EVP_CIPHER_CTX_set_padding - EVP cipher routines
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EVP_CIPHER_CTX_init, EVP_EncryptInit_ex, EVP_EncryptUpdate,
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EVP_EncryptFinal_ex, EVP_DecryptInit_ex, EVP_DecryptUpdate,
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EVP_DecryptFinal_ex, EVP_CipherInit_ex, EVP_CipherUpdate,
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EVP_CipherFinal_ex, EVP_CIPHER_CTX_set_key_length,
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EVP_CIPHER_CTX_ctrl, EVP_CIPHER_CTX_cleanup, EVP_EncryptInit,
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EVP_EncryptFinal, EVP_DecryptInit, EVP_DecryptFinal,
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EVP_CipherInit, EVP_CipherFinal, EVP_get_cipherbyname,
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EVP_get_cipherbynid, EVP_get_cipherbyobj, EVP_CIPHER_nid,
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EVP_CIPHER_block_size, EVP_CIPHER_key_length, EVP_CIPHER_iv_length,
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EVP_CIPHER_flags, EVP_CIPHER_mode, EVP_CIPHER_type, EVP_CIPHER_CTX_cipher,
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EVP_CIPHER_CTX_nid, EVP_CIPHER_CTX_block_size, EVP_CIPHER_CTX_key_length,
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EVP_CIPHER_CTX_iv_length, EVP_CIPHER_CTX_get_app_data,
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EVP_CIPHER_CTX_set_app_data, EVP_CIPHER_CTX_type, EVP_CIPHER_CTX_flags,
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EVP_CIPHER_CTX_mode, EVP_CIPHER_param_to_asn1, EVP_CIPHER_asn1_to_param,
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EVP_CIPHER_CTX_set_padding - EVP cipher routines
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=head1 SYNOPSIS
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#include <openssl/evp.h>
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int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
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unsigned char *key, unsigned char *iv);
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int EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *a);
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int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
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ENGINE *impl, unsigned char *key, unsigned char *iv);
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int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
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int *outl, unsigned char *in, int inl);
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int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out,
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int *outl);
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int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
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ENGINE *impl, unsigned char *key, unsigned char *iv);
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int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
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int *outl, unsigned char *in, int inl);
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int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *outm,
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int *outl);
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int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
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ENGINE *impl, unsigned char *key, unsigned char *iv, int enc);
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int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
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int *outl, unsigned char *in, int inl);
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int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *outm,
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int *outl);
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int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
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unsigned char *key, unsigned char *iv);
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int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out,
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int *outl);
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int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
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unsigned char *key, unsigned char *iv);
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int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
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int *outl, unsigned char *in, int inl);
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int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm,
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int *outl);
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int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
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unsigned char *key, unsigned char *iv, int enc);
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int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
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int *outl, unsigned char *in, int inl);
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int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm,
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int *outl);
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@ -75,14 +96,19 @@ EVP_CIPHER_asn1_to_param, EVP_CIPHER_CTX_set_padding - EVP cipher routines
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The EVP cipher routines are a high level interface to certain
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symmetric ciphers.
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EVP_EncryptInit() initializes a cipher context B<ctx> for encryption
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with cipher B<type>. B<type> is normally supplied by a function such
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as EVP_des_cbc() . B<key> is the symmetric key to use and B<iv> is the
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IV to use (if necessary), the actual number of bytes used for the
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key and IV depends on the cipher. It is possible to set all parameters
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to NULL except B<type> in an initial call and supply the remaining
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parameters in subsequent calls, all of which have B<type> set to NULL.
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This is done when the default cipher parameters are not appropriate.
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EVP_CIPHER_CTX_init() initializes cipher contex B<ctx>.
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EVP_EncryptInit_ex() sets up cipher context B<ctx> for encryption
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with cipher B<type> from ENGINE B<impl>. B<ctx> must be initialized
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before calling this function. B<type> is normally supplied
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by a function such as EVP_des_cbc(). If B<impl> is NULL then the
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default implementation is used. B<key> is the symmetric key to use
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and B<iv> is the IV to use (if necessary), the actual number of bytes
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used for the key and IV depends on the cipher. It is possible to set
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all parameters to NULL except B<type> in an initial call and supply
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the remaining parameters in subsequent calls, all of which have B<type>
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set to NULL. This is done when the default cipher parameters are not
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appropriate.
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EVP_EncryptUpdate() encrypts B<inl> bytes from the buffer B<in> and
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writes the encrypted version to B<out>. This function can be called
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@ -92,7 +118,7 @@ as a result the amount of data written may be anything from zero bytes
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to (inl + cipher_block_size - 1) so B<outl> should contain sufficient
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room. The actual number of bytes written is placed in B<outl>.
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If padding is enabled (the default) then EVP_EncryptFinal() encrypts
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If padding is enabled (the default) then EVP_EncryptFinal_ex() encrypts
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the "final" data, that is any data that remains in a partial block.
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It uses L<standard block padding|/NOTES> (aka PKCS padding). The encrypted
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final data is written to B<out> which should have sufficient space for
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@ -100,11 +126,11 @@ one cipher block. The number of bytes written is placed in B<outl>. After
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this function is called the encryption operation is finished and no further
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calls to EVP_EncryptUpdate() should be made.
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If padding is disabled then EVP_EncryptFinal() will not encrypt any more
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If padding is disabled then EVP_EncryptFinal_ex() will not encrypt any more
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data and it will return an error if any data remains in a partial block:
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that is if the total data length is not a multiple of the block size.
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EVP_DecryptInit(), EVP_DecryptUpdate() and EVP_DecryptFinal() are the
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EVP_DecryptInit_ex(), EVP_DecryptUpdate() and EVP_DecryptFinal_ex() are the
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corresponding decryption operations. EVP_DecryptFinal() will return an
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error code if padding is enabled and the final block is not correctly
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formatted. The parameters and restrictions are identical to the encryption
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@ -113,15 +139,26 @@ passed to EVP_DecryptUpdate() should have sufficient room for
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(B<inl> + cipher_block_size) bytes unless the cipher block size is 1 in
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which case B<inl> bytes is sufficient.
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EVP_CipherInit(), EVP_CipherUpdate() and EVP_CipherFinal() are functions
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that can be used for decryption or encryption. The operation performed
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depends on the value of the B<enc> parameter. It should be set to 1 for
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encryption, 0 for decryption and -1 to leave the value unchanged (the
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actual value of 'enc' being supplied in a previous call).
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EVP_CipherInit_ex(), EVP_CipherUpdate() and EVP_CipherFinal_ex() are
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functions that can be used for decryption or encryption. The operation
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performed depends on the value of the B<enc> parameter. It should be set
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to 1 for encryption, 0 for decryption and -1 to leave the value unchanged
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(the actual value of 'enc' being supplied in a previous call).
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EVP_CIPHER_CTX_cleanup() clears all information from a cipher context.
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It should be called after all operations using a cipher are complete
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so sensitive information does not remain in memory.
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EVP_CIPHER_CTX_cleanup() clears all information from a cipher context
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and free up any allocated memory associate with it. It should be called
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after all operations using a cipher are complete so sensitive information
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does not remain in memory.
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EVP_EncryptInit(), EVP_DecryptInit() and EVP_CipherInit() behave in a
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similar way to EVP_EncryptInit_ex(), EVP_DecryptInit_ex and
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EVP_CipherInit_ex() except the B<ctx> paramter does not need to be
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initialized and they always use the default cipher implementation.
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EVP_EncryptFinal(), EVP_DecryptFinal() and EVP_CipherFinal() behave in a
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similar way to EVP_EncryptFinal_ex(), EVP_DecryptFinal_ex() and
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EVP_CipherFinal_ex() except B<ctx> is automatically cleaned up
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after the call.
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EVP_get_cipherbyname(), EVP_get_cipherbynid() and EVP_get_cipherbyobj()
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return an EVP_CIPHER structure when passed a cipher name, a NID or an
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@ -199,14 +236,14 @@ RC5 can be set.
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=head1 RETURN VALUES
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EVP_EncryptInit(), EVP_EncryptUpdate() and EVP_EncryptFinal() return 1 for success
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and 0 for failure.
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EVP_CIPHER_CTX_init, EVP_EncryptInit_ex(), EVP_EncryptUpdate() and
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EVP_EncryptFinal_ex() return 1 for success and 0 for failure.
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EVP_DecryptInit() and EVP_DecryptUpdate() return 1 for success and 0 for failure.
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EVP_DecryptFinal() returns 0 if the decrypt failed or 1 for success.
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EVP_DecryptInit_ex() and EVP_DecryptUpdate() return 1 for success and 0 for failure.
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EVP_DecryptFinal_ex() returns 0 if the decrypt failed or 1 for success.
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EVP_CipherInit() and EVP_CipherUpdate() return 1 for success and 0 for failure.
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EVP_CipherFinal() returns 1 for a decryption failure or 1 for success.
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EVP_CipherInit_ex() and EVP_CipherUpdate() return 1 for success and 0 for failure.
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EVP_CipherFinal_ex() returns 1 for a decryption failure or 1 for success.
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EVP_CIPHER_CTX_cleanup() returns 1 for success and 0 for failure.
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@ -325,12 +362,12 @@ the input data earlier on will not produce a final decrypt error.
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If padding is disabled then the decryption operation will always succeed if
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the total amount of data decrypted is a multiple of the block size.
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The functions EVP_EncryptInit(), EVP_EncryptUpdate(), EVP_EncryptFinal(),
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EVP_DecryptInit(), EVP_DecryptUpdate(), EVP_CipherInit() and EVP_CipherUpdate()
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and EVP_CIPHER_CTX_cleanup() did not return errors in OpenSSL version 0.9.5a or
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earlier. Software only versions of encryption algorithms will never return
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error codes for these functions, unless there is a programming error (for example
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and attempt to set the key before the cipher is set in EVP_EncryptInit() ).
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The functions EVP_EncryptInit(), EVP_EncryptFinal(), EVP_DecryptInit(),
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EVP_CipherInit() and EVP_CipherFinal() are obsolete but are retained for
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compatibility with existing code. New code should use EVP_EncryptInit_ex(),
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EVP_EncryptFinal_ex(), EVP_DecryptInit_ex(), EVP_DecryptFinal_ex(),
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EVP_CipherInit_ex() and EVP_CipherFinal_ex() because they can reuse an
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existing context without allocating and freeing it up on each call.
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=head1 BUGS
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@ -381,7 +418,8 @@ Encrypt a string using blowfish:
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char intext[] = "Some Crypto Text";
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EVP_CIPHER_CTX ctx;
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FILE *out;
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EVP_EncryptInit(&ctx, EVP_bf_cbc(), key, iv);
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EVP_CIPHER_CTX_init(&ctx);
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EVP_EncryptInit_ex(&ctx, NULL, EVP_bf_cbc(), key, iv);
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if(!EVP_EncryptUpdate(&ctx, outbuf, &outlen, intext, strlen(intext)))
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{
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@ -391,7 +429,7 @@ Encrypt a string using blowfish:
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/* Buffer passed to EVP_EncryptFinal() must be after data just
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* encrypted to avoid overwriting it.
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*/
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if(!EVP_EncryptFinal(&ctx, outbuf + outlen, &tmplen))
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if(!EVP_EncryptFinal_ex(&ctx, outbuf + outlen, &tmplen))
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{
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/* Error */
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return 0;
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@ -428,10 +466,11 @@ General encryption, decryption function example using FILE I/O and RC2 with an
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unsigned char key[] = "0123456789";
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unsigned char iv[] = "12345678";
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/* Don't set key or IV because we will modify the parameters */
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EVP_CipherInit(&ctx, EVP_rc2(), NULL, NULL, do_encrypt);
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EVP_CIPHER_CTX_init(&ctx);
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EVP_CipherInit_ex(&ctx, EVP_rc2(), NULL, NULL, NULL, do_encrypt);
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EVP_CIPHER_CTX_set_key_length(&ctx, 10);
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/* We finished modifying parameters so now we can set key and IV */
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EVP_CipherInit(&ctx, NULL, key, iv, do_encrypt);
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EVP_CipherInit_ex(&ctx, NULL, NULL, key, iv, do_encrypt);
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for(;;)
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{
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@ -444,7 +483,7 @@ General encryption, decryption function example using FILE I/O and RC2 with an
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}
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fwrite(outbuf, 1, outlen, out);
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}
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if(!EVP_CipherFinal(&ctx, outbuf, &outlen))
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if(!EVP_CipherFinal_ex(&ctx, outbuf, &outlen))
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{
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/* Error */
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return 0;
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@ -8,10 +8,12 @@ EVP_SignInit, EVP_SignUpdate, EVP_SignFinal - EVP signing functions
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#include <openssl/evp.h>
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void EVP_SignInit(EVP_MD_CTX *ctx, const EVP_MD *type);
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void EVP_SignUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt);
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int EVP_SignInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl);
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int EVP_SignUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt);
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int EVP_SignFinal(EVP_MD_CTX *ctx,unsigned char *sig,unsigned int *s, EVP_PKEY *pkey);
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void EVP_SignInit(EVP_MD_CTX *ctx, const EVP_MD *type);
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int EVP_PKEY_size(EVP_PKEY *pkey);
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=head1 DESCRIPTION
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@ -19,9 +21,9 @@ EVP_SignInit, EVP_SignUpdate, EVP_SignFinal - EVP signing functions
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The EVP signature routines are a high level interface to digital
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signatures.
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EVP_SignInit() initializes a signing context B<ctx> to using digest
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B<type>: this will typically be supplied by a function such as
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EVP_sha1().
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EVP_SignInit_ex() sets up signing context B<ctx> to use digest
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B<type> from ENGINE B<impl>. B<ctx> must be initialized with
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EVP_MD_CTX_init() before calling this function.
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EVP_SignUpdate() hashes B<cnt> bytes of data at B<d> into the
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signature context B<ctx>. This function can be called several times on the
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@ -31,18 +33,18 @@ EVP_SignFinal() signs the data in B<ctx> using the private key B<pkey>
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and places the signature in B<sig>. If the B<s> parameter is not NULL
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then the number of bytes of data written (i.e. the length of the signature)
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will be written to the integer at B<s>, at most EVP_PKEY_size(pkey) bytes
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will be written. After calling EVP_SignFinal() no additional calls to
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EVP_SignUpdate() can be made, but EVP_SignInit() can be called to initialize
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a new signature operation.
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will be written.
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EVP_SignInit() initializes a signing context B<ctx> to use the default
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implementation of digest B<type>.
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EVP_PKEY_size() returns the maximum size of a signature in bytes. The actual
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signature returned by EVP_SignFinal() may be smaller.
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=head1 RETURN VALUES
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EVP_SignInit() and EVP_SignUpdate() do not return values.
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EVP_SignFinal() returns 1 for success and 0 for failure.
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EVP_SignInit_ex(), EVP_SignUpdate() and EVP_SignFinal() return 1
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for success and 0 for failure.
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EVP_PKEY_size() returns the maximum size of a signature in bytes.
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@ -63,11 +65,18 @@ When signing with DSA private keys the random number generator must be seeded
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or the operation will fail. The random number generator does not need to be
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seeded for RSA signatures.
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The call to EVP_SignFinal() internally finalizes a copy of the digest context.
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This means that calls to EVP_SignUpdate() and EVP_SignFinal() can be called
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later to digest and sign additional data.
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Since only a copy of the digest context is ever finalized the context must
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be cleaned up after use by calling EVP_MD_CTX_cleanup() or a memory leak
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will occur.
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=head1 BUGS
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Several of the functions do not return values: maybe they should. Although the
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internal digest operations will never fail some future hardware based operations
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might.
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Older versions of this documentation wrongly stated that calls to
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EVP_SignUpdate() could not be made after calling EVP_SignFinal().
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=head1 SEE ALSO
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@ -82,4 +91,6 @@ L<sha(3)|sha(3)>, L<digest(1)|digest(1)>
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EVP_SignInit(), EVP_SignUpdate() and EVP_SignFinal() are
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available in all versions of SSLeay and OpenSSL.
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EVP_SignInit_ex() was added in OpenSSL 0.9.7
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=cut
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@ -8,30 +8,35 @@ EVP_VerifyInit, EVP_VerifyUpdate, EVP_VerifyFinal - EVP signature verification f
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#include <openssl/evp.h>
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void EVP_VerifyInit(EVP_MD_CTX *ctx, const EVP_MD *type);
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void EVP_VerifyUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt);
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int EVP_VerifyInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl);
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int EVP_VerifyUpdate(EVP_MD_CTX *ctx, const void *d, unsigned int cnt);
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int EVP_VerifyFinal(EVP_MD_CTX *ctx,unsigned char *sigbuf, unsigned int siglen,EVP_PKEY *pkey);
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|
||||
int EVP_VerifyInit(EVP_MD_CTX *ctx, const EVP_MD *type);
|
||||
|
||||
=head1 DESCRIPTION
|
||||
|
||||
The EVP signature verification routines are a high level interface to digital
|
||||
signatures.
|
||||
|
||||
EVP_VerifyInit() initializes a verification context B<ctx> to using digest
|
||||
B<type>: this will typically be supplied by a function such as EVP_sha1().
|
||||
EVP_VerifyInit_ex() sets up verification context B<ctx> to use digest
|
||||
B<type> from ENGINE B<impl>. B<ctx> must be initialized by calling
|
||||
EVP_MD_CTX_init() before calling this function.
|
||||
|
||||
EVP_VerifyUpdate() hashes B<cnt> bytes of data at B<d> into the
|
||||
verification context B<ctx>. This function can be called several times on the
|
||||
same B<ctx> to include additional data.
|
||||
|
||||
EVP_VerifyFinal() verifies the data in B<ctx> using the public key B<pkey>
|
||||
and against the B<siglen> bytes at B<sigbuf>. After calling EVP_VerifyFinal()
|
||||
no additional calls to EVP_VerifyUpdate() can be made, but EVP_VerifyInit()
|
||||
can be called to initialize a new verification operation.
|
||||
and against the B<siglen> bytes at B<sigbuf>.
|
||||
|
||||
EVP_VerifyInit() initializes verification context B<ctx> to use the default
|
||||
implementation of digest B<type>.
|
||||
|
||||
=head1 RETURN VALUES
|
||||
|
||||
EVP_VerifyInit() and EVP_VerifyUpdate() do not return values.
|
||||
EVP_VerifyInit_ex() and EVP_VerifyUpdate() return 1 for success and 0 for
|
||||
failure.
|
||||
|
||||
EVP_VerifyFinal() returns 1 for a correct signature, 0 for failure and -1 if some
|
||||
other error occurred.
|
||||
@ -49,11 +54,18 @@ digest algorithm must be used with the correct public key type. A list of
|
||||
algorithms and associated public key algorithms appears in
|
||||
L<EVP_DigestInit(3)|EVP_DigestInit(3)>.
|
||||
|
||||
The call to EVP_VerifyFinal() internally finalizes a copy of the digest context.
|
||||
This means that calls to EVP_VerifyUpdate() and EVP_VerifyFinal() can be called
|
||||
later to digest and verify additional data.
|
||||
|
||||
Since only a copy of the digest context is ever finalized the context must
|
||||
be cleaned up after use by calling EVP_MD_CTX_cleanup() or a memory leak
|
||||
will occur.
|
||||
|
||||
=head1 BUGS
|
||||
|
||||
Several of the functions do not return values: maybe they should. Although the
|
||||
internal digest operations will never fail some future hardware based operations
|
||||
might.
|
||||
Older versions of this documentation wrongly stated that calls to
|
||||
EVP_VerifyUpdate() could not be made after calling EVP_VerifyFinal().
|
||||
|
||||
=head1 SEE ALSO
|
||||
|
||||
@ -69,4 +81,6 @@ L<sha(3)|sha(3)>, L<digest(1)|digest(1)>
|
||||
EVP_VerifyInit(), EVP_VerifyUpdate() and EVP_VerifyFinal() are
|
||||
available in all versions of SSLeay and OpenSSL.
|
||||
|
||||
EVP_VerifyInit_ex() was added in OpenSSL 0.9.7
|
||||
|
||||
=cut
|
||||
|
||||
Loading…
Reference in New Issue
Block a user