convert EVP manuals from pod to mdoc

1 files changed, 0 insertions, 548 deletions

diff --git a/src/lib/libcrypto/doc/EVP_EncryptInit.pod b/src/lib/libcrypto/doc/EVP_EncryptInit.pod
deleted file mode 100644
index 7ae3fe31ea..0000000000
--- a/src/lib/libcrypto/doc/EVP_EncryptInit.pod
+++ /dev/null
@@ -1,548 +0,0 @@
-=pod
-
-=head1 NAME
-
-EVP_CIPHER_CTX_init, EVP_EncryptInit_ex, EVP_EncryptUpdate,
-EVP_EncryptFinal_ex, EVP_DecryptInit_ex, EVP_DecryptUpdate,
-EVP_DecryptFinal_ex, EVP_CipherInit_ex, EVP_CipherUpdate,
-EVP_CipherFinal_ex, EVP_CIPHER_CTX_set_key_length,
-EVP_CIPHER_CTX_ctrl, EVP_CIPHER_CTX_cleanup, EVP_EncryptInit,
-EVP_EncryptFinal, EVP_DecryptInit, EVP_DecryptFinal,
-EVP_CipherInit, EVP_CipherFinal, EVP_get_cipherbyname,
-EVP_get_cipherbynid, EVP_get_cipherbyobj, EVP_CIPHER_nid,
-EVP_CIPHER_block_size, EVP_CIPHER_key_length, EVP_CIPHER_iv_length,
-EVP_CIPHER_flags, EVP_CIPHER_mode, EVP_CIPHER_type, EVP_CIPHER_CTX_cipher,
-EVP_CIPHER_CTX_nid, EVP_CIPHER_CTX_block_size, EVP_CIPHER_CTX_key_length,
-EVP_CIPHER_CTX_iv_length, EVP_CIPHER_CTX_get_app_data,
-EVP_CIPHER_CTX_set_app_data, EVP_CIPHER_CTX_type, EVP_CIPHER_CTX_flags,
-EVP_CIPHER_CTX_mode, EVP_CIPHER_param_to_asn1, EVP_CIPHER_asn1_to_param,
-EVP_CIPHER_CTX_set_padding,  EVP_enc_null, EVP_des_cbc, EVP_des_ecb,
-EVP_des_cfb, EVP_des_ofb, EVP_des_ede_cbc, EVP_des_ede, EVP_des_ede_ofb,
-EVP_des_ede_cfb, EVP_des_ede3_cbc, EVP_des_ede3, EVP_des_ede3_ofb,
-EVP_des_ede3_cfb, EVP_desx_cbc, EVP_rc4, EVP_rc4_40, EVP_idea_cbc,
-EVP_idea_ecb, EVP_idea_cfb, EVP_idea_ofb, EVP_idea_cbc, EVP_rc2_cbc,
-EVP_rc2_ecb, EVP_rc2_cfb, EVP_rc2_ofb, EVP_rc2_40_cbc, EVP_rc2_64_cbc,
-EVP_bf_cbc, EVP_bf_ecb, EVP_bf_cfb, EVP_bf_ofb, EVP_cast5_cbc,
-EVP_cast5_ecb, EVP_cast5_cfb, EVP_cast5_ofb,
-EVP_aes_128_gcm, EVP_aes_192_gcm, EVP_aes_256_gcm, EVP_aes_128_ccm,
-EVP_aes_192_ccm, EVP_aes_256_ccm, EVP_rc5_32_12_16_cbc,
-EVP_rc5_32_12_16_cfb, EVP_rc5_32_12_16_ecb, EVP_rc5_32_12_16_ofb
-- EVP cipher routines
-
-=head1 SYNOPSIS
-
- #include <openssl/evp.h>
-
- void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *a);
-
- int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-         ENGINE *impl, unsigned char *key, unsigned char *iv);
- int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
-         int *outl, unsigned char *in, int inl);
- int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out,
-         int *outl);
-
- int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-         ENGINE *impl, unsigned char *key, unsigned char *iv);
- int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
-         int *outl, unsigned char *in, int inl);
- int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *outm,
-         int *outl);
-
- int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-         ENGINE *impl, unsigned char *key, unsigned char *iv, int enc);
- int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
-         int *outl, unsigned char *in, int inl);
- int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *outm,
-         int *outl);
-
- int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-         unsigned char *key, unsigned char *iv);
- int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out,
-         int *outl);
-
- int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-         unsigned char *key, unsigned char *iv);
- int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm,
-         int *outl);
-
- int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
-         unsigned char *key, unsigned char *iv, int enc);
- int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm,
-         int *outl);
-
- int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *x, int padding);
- int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *x, int keylen);
- int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr);
- int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *a);
-
- const EVP_CIPHER *EVP_get_cipherbyname(const char *name);
- #define EVP_get_cipherbynid(a) EVP_get_cipherbyname(OBJ_nid2sn(a))
- #define EVP_get_cipherbyobj(a) EVP_get_cipherbynid(OBJ_obj2nid(a))
-
- #define EVP_CIPHER_nid(e)              ((e)->nid)
- #define EVP_CIPHER_block_size(e)       ((e)->block_size)
- #define EVP_CIPHER_key_length(e)       ((e)->key_len)
- #define EVP_CIPHER_iv_length(e)                ((e)->iv_len)
- #define EVP_CIPHER_flags(e)            ((e)->flags)
- #define EVP_CIPHER_mode(e)             ((e)->flags) & EVP_CIPH_MODE)
- int EVP_CIPHER_type(const EVP_CIPHER *ctx);
-
- #define EVP_CIPHER_CTX_cipher(e)       ((e)->cipher)
- #define EVP_CIPHER_CTX_nid(e)          ((e)->cipher->nid)
- #define EVP_CIPHER_CTX_block_size(e)   ((e)->cipher->block_size)
- #define EVP_CIPHER_CTX_key_length(e)   ((e)->key_len)
- #define EVP_CIPHER_CTX_iv_length(e)    ((e)->cipher->iv_len)
- #define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data)
- #define EVP_CIPHER_CTX_set_app_data(e,d) ((e)->app_data=(char *)(d))
- #define EVP_CIPHER_CTX_type(c)         EVP_CIPHER_type(EVP_CIPHER_CTX_cipher(c))
- #define EVP_CIPHER_CTX_flags(e)                ((e)->cipher->flags)
- #define EVP_CIPHER_CTX_mode(e)         ((e)->cipher->flags & EVP_CIPH_MODE)
-
- int EVP_CIPHER_param_to_asn1(EVP_CIPHER_CTX *c, ASN1_TYPE *type);
- int EVP_CIPHER_asn1_to_param(EVP_CIPHER_CTX *c, ASN1_TYPE *type);
-
-=head1 DESCRIPTION
-
-The EVP cipher routines are a high level interface to certain
-symmetric ciphers.
-
-EVP_CIPHER_CTX_init() initializes cipher context B<ctx>.
-
-EVP_EncryptInit_ex() sets up cipher context B<ctx> for encryption
-with cipher B<type> from ENGINE B<impl>. B<ctx> must be initialized
-before calling this function. B<type> is normally supplied
-by a function such as EVP_aes_256_cbc(). If B<impl> is NULL then the
-default implementation is used. B<key> is the symmetric key to use
-and B<iv> is the IV to use (if necessary), the actual number of bytes
-used for the key and IV depends on the cipher. It is possible to set
-all parameters to NULL except B<type> in an initial call and supply
-the remaining parameters in subsequent calls, all of which have B<type>
-set to NULL. This is done when the default cipher parameters are not
-appropriate.
-
-EVP_EncryptUpdate() encrypts B<inl> bytes from the buffer B<in> and
-writes the encrypted version to B<out>. This function can be called
-multiple times to encrypt successive blocks of data. The amount
-of data written depends on the block alignment of the encrypted data:
-as a result the amount of data written may be anything from zero bytes
-to (inl + cipher_block_size - 1) so B<outl> should contain sufficient
-room. The actual number of bytes written is placed in B<outl>.
-
-If padding is enabled (the default) then EVP_EncryptFinal_ex() encrypts
-the "final" data, that is any data that remains in a partial block.
-It uses L<standard block padding|/NOTES> (aka PKCS padding). The encrypted
-final data is written to B<out> which should have sufficient space for
-one cipher block. The number of bytes written is placed in B<outl>. After
-this function is called the encryption operation is finished and no further
-calls to EVP_EncryptUpdate() should be made.
-
-If padding is disabled then EVP_EncryptFinal_ex() will not encrypt any more
-data and it will return an error if any data remains in a partial block:
-that is if the total data length is not a multiple of the block size.
-
-EVP_DecryptInit_ex(), EVP_DecryptUpdate() and EVP_DecryptFinal_ex() are the
-corresponding decryption operations. EVP_DecryptFinal() will return an
-error code if padding is enabled and the final block is not correctly
-formatted. The parameters and restrictions are identical to the encryption
-operations except that if padding is enabled the decrypted data buffer B<out>
-passed to EVP_DecryptUpdate() should have sufficient room for
-(B<inl> + cipher_block_size) bytes unless the cipher block size is 1 in
-which case B<inl> bytes is sufficient.
-
-EVP_CipherInit_ex(), EVP_CipherUpdate() and EVP_CipherFinal_ex() are
-functions that can be used for decryption or encryption. The operation
-performed depends on the value of the B<enc> parameter. It should be set
-to 1 for encryption, 0 for decryption and -1 to leave the value unchanged
-(the actual value of 'enc' being supplied in a previous call).
-
-EVP_CIPHER_CTX_cleanup() clears all information from a cipher context
-and free up any allocated memory associate with it. It should be called
-after all operations using a cipher are complete so sensitive information
-does not remain in memory.
-
-EVP_EncryptInit(), EVP_DecryptInit() and EVP_CipherInit() behave in a
-similar way to EVP_EncryptInit_ex(), EVP_DecryptInit_ex and
-EVP_CipherInit_ex() except the B<ctx> parameter does not need to be
-initialized and they always use the default cipher implementation.
-
-EVP_EncryptFinal(), EVP_DecryptFinal() and EVP_CipherFinal() are
-identical to EVP_EncryptFinal_ex(), EVP_DecryptFinal_ex() and
-EVP_CipherFinal_ex(). In previous releases of OpenSSL they also used to clean
-up the B<ctx>, but this is no longer done and EVP_CIPHER_CTX_clean()
-must be called to free any context resources.
-
-EVP_get_cipherbyname(), EVP_get_cipherbynid() and EVP_get_cipherbyobj()
-return an EVP_CIPHER structure when passed a cipher name, a NID or an
-ASN1_OBJECT structure.
-
-EVP_CIPHER_nid() and EVP_CIPHER_CTX_nid() return the NID of a cipher when
-passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX> structure.  The actual NID
-value is an internal value which may not have a corresponding OBJECT
-IDENTIFIER.
-
-EVP_CIPHER_CTX_set_padding() enables or disables padding. By default
-encryption operations are padded using standard block padding and the
-padding is checked and removed when decrypting. If the B<pad> parameter
-is zero then no padding is performed, the total amount of data encrypted
-or decrypted must then be a multiple of the block size or an error will
-occur.
-
-EVP_CIPHER_key_length() and EVP_CIPHER_CTX_key_length() return the key
-length of a cipher when passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX>
-structure. The constant B<EVP_MAX_KEY_LENGTH> is the maximum key length
-for all ciphers. Note: although EVP_CIPHER_key_length() is fixed for a
-given cipher, the value of EVP_CIPHER_CTX_key_length() may be different
-for variable key length ciphers.
-
-EVP_CIPHER_CTX_set_key_length() sets the key length of the cipher ctx.
-If the cipher is a fixed length cipher then attempting to set the key
-length to any value other than the fixed value is an error.
-
-EVP_CIPHER_iv_length() and EVP_CIPHER_CTX_iv_length() return the IV
-length of a cipher when passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX>.
-It will return zero if the cipher does not use an IV.  The constant
-B<EVP_MAX_IV_LENGTH> is the maximum IV length for all ciphers.
-
-EVP_CIPHER_block_size() and EVP_CIPHER_CTX_block_size() return the block
-size of a cipher when passed an B<EVP_CIPHER> or B<EVP_CIPHER_CTX>
-structure. The constant B<EVP_MAX_IV_LENGTH> is also the maximum block
-length for all ciphers.
-
-EVP_CIPHER_type() and EVP_CIPHER_CTX_type() return the type of the passed
-cipher or context. This "type" is the actual NID of the cipher OBJECT
-IDENTIFIER as such it ignores the cipher parameters and 40 bit RC2 and
-128 bit RC2 have the same NID. If the cipher does not have an object
-identifier or does not have ASN1 support this function will return
-B<NID_undef>.
-
-EVP_CIPHER_CTX_cipher() returns the B<EVP_CIPHER> structure when passed
-an B<EVP_CIPHER_CTX> structure.
-
-EVP_CIPHER_mode() and EVP_CIPHER_CTX_mode() return the block cipher mode:
-EVP_CIPH_ECB_MODE, EVP_CIPH_CBC_MODE, EVP_CIPH_CFB_MODE or
-EVP_CIPH_OFB_MODE. If the cipher is a stream cipher then
-EVP_CIPH_STREAM_CIPHER is returned.
-
-EVP_CIPHER_param_to_asn1() sets the AlgorithmIdentifier "parameter" based
-on the passed cipher. This will typically include any parameters and an
-IV. The cipher IV (if any) must be set when this call is made. This call
-should be made before the cipher is actually "used" (before any
-EVP_EncryptUpdate(), EVP_DecryptUpdate() calls for example). This function
-may fail if the cipher does not have any ASN1 support.
-
-EVP_CIPHER_asn1_to_param() sets the cipher parameters based on an ASN1
-AlgorithmIdentifier "parameter". The precise effect depends on the cipher
-In the case of RC2, for example, it will set the IV and effective key length.
-This function should be called after the base cipher type is set but before
-the key is set. For example EVP_CipherInit() will be called with the IV and
-key set to NULL, EVP_CIPHER_asn1_to_param() will be called and finally
-EVP_CipherInit() again with all parameters except the key set to NULL. It is
-possible for this function to fail if the cipher does not have any ASN1 support
-or the parameters cannot be set (for example the RC2 effective key length
-is not supported.
-
-EVP_CIPHER_CTX_ctrl() allows various cipher specific parameters to be determined
-and set. Currently only the RC2 effective key length and the number of rounds of
-RC5 can be set.
-
-=head1 RETURN VALUES
-
-EVP_EncryptInit_ex(), EVP_EncryptUpdate() and EVP_EncryptFinal_ex()
-return 1 for success and 0 for failure.
-
-EVP_DecryptInit_ex() and EVP_DecryptUpdate() return 1 for success and 0 for
-failure.  EVP_DecryptFinal_ex() returns 0 if the decrypt failed or 1 for
-success.
-
-EVP_CipherInit_ex() and EVP_CipherUpdate() return 1 for success and 0 for
-failure.  EVP_CipherFinal_ex() returns 0 for a decryption failure or 1 for
-success.
-
-EVP_CIPHER_CTX_cleanup() returns 1 for success and 0 for failure.
-
-EVP_get_cipherbyname(), EVP_get_cipherbynid() and EVP_get_cipherbyobj()
-return an B<EVP_CIPHER> structure or NULL on error.
-
-EVP_CIPHER_nid() and EVP_CIPHER_CTX_nid() return a NID.
-
-EVP_CIPHER_block_size() and EVP_CIPHER_CTX_block_size() return the block
-size.
-
-EVP_CIPHER_key_length() and EVP_CIPHER_CTX_key_length() return the key
-length.
-
-EVP_CIPHER_CTX_set_padding() always returns 1.
-
-EVP_CIPHER_iv_length() and EVP_CIPHER_CTX_iv_length() return the IV
-length or zero if the cipher does not use an IV.
-
-EVP_CIPHER_type() and EVP_CIPHER_CTX_type() return the NID of the cipher's
-OBJECT IDENTIFIER or NID_undef if it has no defined OBJECT IDENTIFIER.
-
-EVP_CIPHER_CTX_cipher() returns an B<EVP_CIPHER> structure.
-
-EVP_CIPHER_param_to_asn1() and EVP_CIPHER_asn1_to_param() return 1 for
-success or zero for failure.
-
-=head1 CIPHER LISTING
-
-All algorithms have a fixed key length unless otherwise stated.
-
-=over 4
-
-=item EVP_enc_null(void)
-
-Null cipher: does nothing.
-
-=item EVP_aes_128_cbc(void), EVP_aes_128_ecb(void), EVP_aes_128_cfb(void), EVP_aes_128_ofb(void)
-
-128-bit AES in CBC, ECB, CFB and OFB modes respectively.
-
-=item EVP_aes_192_cbc(void), EVP_aes_192_ecb(void), EVP_aes_192_cfb(void), EVP_aes_192_ofb(void)
-
-192-bit AES in CBC, ECB, CFB and OFB modes respectively.
-
-=item EVP_aes_256_cbc(void), EVP_aes_256_ecb(void), EVP_aes_256_cfb(void), EVP_aes_256_ofb(void)
-
-256-bit AES in CBC, ECB, CFB and OFB modes respectively.
-
-=item EVP_des_cbc(void), EVP_des_ecb(void), EVP_des_cfb(void), EVP_des_ofb(void)
-
-DES in CBC, ECB, CFB and OFB modes respectively.
-
-=item EVP_des_ede_cbc(void), EVP_des_ede(), EVP_des_ede_ofb(void),
-EVP_des_ede_cfb(void)
-
-Two key triple DES in CBC, ECB, CFB and OFB modes respectively.
-
-=item EVP_des_ede3_cbc(void), EVP_des_ede3(), EVP_des_ede3_ofb(void),
-EVP_des_ede3_cfb(void)
-
-Three key triple DES in CBC, ECB, CFB and OFB modes respectively.
-
-=item EVP_desx_cbc(void)
-
-DESX algorithm in CBC mode.
-
-=item EVP_rc4(void)
-
-RC4 stream cipher. This is a variable key length cipher with default key length
-128 bits.
-
-=item EVP_rc4_40(void)
-
-RC4 stream cipher with 40 bit key length. This is obsolete and new code should
-use EVP_rc4() and the EVP_CIPHER_CTX_set_key_length() function.
-
-=item EVP_idea_cbc() EVP_idea_ecb(void), EVP_idea_cfb(void),
-EVP_idea_ofb(void), EVP_idea_cbc(void)
-
-IDEA encryption algorithm in CBC, ECB, CFB and OFB modes respectively.
-
-=item EVP_rc2_cbc(void), EVP_rc2_ecb(void), EVP_rc2_cfb(void), EVP_rc2_ofb(void)
-
-RC2 encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is a
-variable key length cipher with an additional parameter called "effective key
-bits" or "effective key length".  By default both are set to 128 bits.
-
-=item EVP_rc2_40_cbc(void), EVP_rc2_64_cbc(void)
-
-RC2 algorithm in CBC mode with a default key length and effective key length of
-40 and 64 bits.  These are obsolete and new code should use EVP_rc2_cbc(),
-EVP_CIPHER_CTX_set_key_length() and EVP_CIPHER_CTX_ctrl() to set the key length
-and effective key length.
-
-=item EVP_bf_cbc(void), EVP_bf_ecb(void), EVP_bf_cfb(void), EVP_bf_ofb(void);
-
-Blowfish encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This
-is a variable key length cipher.
-
-=item EVP_cast5_cbc(void), EVP_cast5_ecb(void), EVP_cast5_cfb(void),
-EVP_cast5_ofb(void)
-
-CAST encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is
-a variable key length cipher.
-
-=item EVP_rc5_32_12_16_cbc(void), EVP_rc5_32_12_16_ecb(void),
-EVP_rc5_32_12_16_cfb(void), EVP_rc5_32_12_16_ofb(void)
-
-RC5 encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is a
-variable key length cipher with an additional "number of rounds" parameter. By
-default the key length is set to 128 bits and 12 rounds.
-
-=back
-
-=head1 NOTES
-
-Where possible the B<EVP> interface to symmetric ciphers should be used in
-preference to the low level interfaces. This is because the code then becomes
-transparent to the cipher used and much more flexible.
-
-PKCS padding works by adding B<n> padding bytes of value B<n> to make the total
-length of the encrypted data a multiple of the block size. Padding is always
-added so if the data is already a multiple of the block size B<n> will equal
-the block size. For example if the block size is 8 and 11 bytes are to be
-encrypted then 5 padding bytes of value 5 will be added.
-
-When decrypting the final block is checked to see if it has the correct form.
-
-Although the decryption operation can produce an error if padding is enabled,
-it is not a strong test that the input data or key is correct. A random block
-has better than 1 in 256 chance of being of the correct format and problems with
-the input data earlier on will not produce a final decrypt error.
-
-If padding is disabled then the decryption operation will always succeed if
-the total amount of data decrypted is a multiple of the block size.
-
-The functions EVP_EncryptInit(), EVP_EncryptFinal(), EVP_DecryptInit(),
-EVP_CipherInit() and EVP_CipherFinal() are obsolete but are retained for
-compatibility with existing code. New code should use EVP_EncryptInit_ex(),
-EVP_EncryptFinal_ex(), EVP_DecryptInit_ex(), EVP_DecryptFinal_ex(),
-EVP_CipherInit_ex() and EVP_CipherFinal_ex() because they can reuse an
-existing context without allocating and freeing it up on each call.
-
-=head1 BUGS
-
-For RC5 the number of rounds can currently only be set to 8, 12 or 16. This is
-a limitation of the current RC5 code rather than the EVP interface.
-
-EVP_MAX_KEY_LENGTH and EVP_MAX_IV_LENGTH only refer to the internal ciphers with
-default key lengths. If custom ciphers exceed these values the results are
-unpredictable. This is because it has become standard practice to define a
-generic key as a fixed unsigned char array containing EVP_MAX_KEY_LENGTH bytes.
-
-The ASN1 code is incomplete (and sometimes inaccurate) it has only been tested
-for certain common S/MIME ciphers (RC2, DES, triple DES) in CBC mode.
-
-=head1 EXAMPLES
-
-Get the number of rounds used in RC5:
-
- int nrounds;
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC5_ROUNDS, 0, &nrounds);
-
-Get the RC2 effective key length:
-
- int key_bits;
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC2_KEY_BITS, 0, &key_bits);
-
-Set the number of rounds used in RC5:
-
- int nrounds;
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC5_ROUNDS, nrounds, NULL);
-
-Set the effective key length used in RC2:
-
- int key_bits;
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC2_KEY_BITS, key_bits, NULL);
-
-Encrypt a string using blowfish:
-
- int
- do_crypt(char *outfile)
- {
-        unsigned char outbuf[1024];
-        int outlen, tmplen;
-        /*
-         * Bogus key and IV: we'd normally set these from
-         * another source.
-         */
-        unsigned char key[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
-        unsigned char iv[] = {1,2,3,4,5,6,7,8};
-        const char intext[] = "Some Crypto Text";
-        EVP_CIPHER_CTX ctx;
-        FILE *out;
-        EVP_CIPHER_CTX_init(&ctx);
-        EVP_EncryptInit_ex(&ctx, EVP_bf_cbc(), NULL, key, iv);
-
-        if (!EVP_EncryptUpdate(&ctx, outbuf, &outlen, intext,
-            strlen(intext))) {
-                /* Error */
-                return 0;
-        }
-        /*
-         * Buffer passed to EVP_EncryptFinal() must be after data just
-         * encrypted to avoid overwriting it.
-         */
-        if (!EVP_EncryptFinal_ex(&ctx, outbuf + outlen, &tmplen)) {
-                /* Error */
-                return 0;
-        }
-        outlen += tmplen;
-        EVP_CIPHER_CTX_cleanup(&ctx);
-        /*
-         * Need binary mode for fopen because encrypted data is
-         * binary data. Also cannot use strlen() on it because
-         * it won't be NUL terminated and may contain embedded
-         * NULs.
-         */
-        out = fopen(outfile, "wb");
-        fwrite(outbuf, 1, outlen, out);
-        fclose(out);
-        return 1;
- }
-
-The ciphertext from the above example can be decrypted using the B<openssl>
-utility with the command line:
-
- S<openssl bf -in cipher.bin -K 000102030405060708090A0B0C0D0E0F -iv 0102030405060708 -d>
-
-General encryption, decryption function example using FILE I/O and RC2 with an
-80 bit key:
-
- int
- do_crypt(FILE *in, FILE *out, int do_encrypt)
- {
-        /* Allow enough space in output buffer for additional block */
-        inbuf[1024], outbuf[1024 + EVP_MAX_BLOCK_LENGTH];
-        int inlen, outlen;
-        /*
-         * Bogus key and IV: we'd normally set these from
-         * another source.
-         */
-        unsigned char key[] = "0123456789";
-        unsigned char iv[] = "12345678";
-
-        /* Don't set key or IV because we will modify the parameters */
-        EVP_CIPHER_CTX_init(&ctx);
-        EVP_CipherInit_ex(&ctx, EVP_rc2(), NULL, NULL, NULL, do_encrypt);
-        EVP_CIPHER_CTX_set_key_length(&ctx, 10);
-        /* We finished modifying parameters so now we can set key and IV */
-        EVP_CipherInit_ex(&ctx, NULL, NULL, key, iv, do_encrypt);
-
-        for(;;) {
-                inlen = fread(inbuf, 1, 1024, in);
-                if (inlen <= 0)
-                        break;
-                if (!EVP_CipherUpdate(&ctx, outbuf, &outlen, inbuf,
-                    inlen)) {
-                        /* Error */
-                        EVP_CIPHER_CTX_cleanup(&ctx);
-                        return 0;
-                }
-                fwrite(outbuf, 1, outlen, out);
-        }
-        if (!EVP_CipherFinal_ex(&ctx, outbuf, &outlen)) {
-                /* Error */
-                EVP_CIPHER_CTX_cleanup(&ctx);
-                return 0;
-        }
-        fwrite(outbuf, 1, outlen, out);
-
-        EVP_CIPHER_CTX_cleanup(&ctx);
-        return 1;
- }
-
-=head1 SEE ALSO
-
-L<evp(3)|evp(3)>
-
-=head1 HISTORY
-
-EVP_CIPHER_CTX_init(), EVP_EncryptInit_ex(), EVP_EncryptFinal_ex(),
-EVP_DecryptInit_ex(), EVP_DecryptFinal_ex(), EVP_CipherInit_ex(),
-EVP_CipherFinal_ex() and EVP_CIPHER_CTX_set_padding() appeared in
-OpenSSL 0.9.7.
-
-=cut