=head1 NAME
-EVP_EncryptInit, EVP_EncryptUpdate, EVP_EncryptFinal, EVP_DecryptInit,
-EVP_DecryptUpdate, EVP_DecryptFinal, EVP_CipherInit, EVP_CipherUpdate,
-EVP_CipherFinal, EVP_CIPHER_CTX_set_key_length, EVP_CIPHER_CTX_ctrl,
-EVP_CIPHER_CTX_cleanup, 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 routines
+EVP_CIPHER_CTX_new, EVP_CIPHER_CTX_reset, EVP_CIPHER_CTX_free,
+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_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_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_rc5_32_12_16_cbc,
+EVP_rc5_32_12_16_ecb, EVP_rc5_32_12_16_cfb, EVP_rc5_32_12_16_ofb,
+EVP_aes_128_cbc, EVP_aes_128_ecb, EVP_aes_128_cfb, EVP_aes_128_ofb,
+EVP_aes_192_cbc, EVP_aes_192_ecb, EVP_aes_192_cfb, EVP_aes_192_ofb,
+EVP_aes_256_cbc, EVP_aes_256_ecb, EVP_aes_256_cfb, EVP_aes_256_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 cipher routines
+
+=for comment generic
=head1 SYNOPSIS
#include <openssl/evp.h>
- int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
- unsigned char *key, unsigned char *iv);
+ EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void);
+ int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX *ctx);
+ void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx);
+
+ 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_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
- int *outl, unsigned char *in, int inl);
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_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
- int *outl, unsigned char *in, int inl);
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)
+ #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)
+ const EVP_CIPHER *EVP_CIPHER_CTX_cipher(const EVP_CIPHER_CTX *ctx);
+ int EVP_CIPHER_CTX_nid(const EVP_CIPHER_CTX *ctx);
+ int EVP_CIPHER_CTX_block_size(const EVP_CIPHER_CTX *ctx);
+ int EVP_CIPHER_CTX_key_length(const EVP_CIPHER_CTX *ctx);
+ int EVP_CIPHER_CTX_iv_length(const EVP_CIPHER_CTX *ctx);
+ void *EVP_CIPHER_CTX_get_app_data(const EVP_CIPHER_CTX *ctx);
+ void EVP_CIPHER_CTX_set_app_data(const EVP_CIPHER_CTX *ctx, void *data);
+ int EVP_CIPHER_CTX_type(const EVP_CIPHER_CTX *ctx);
+ int EVP_CIPHER_CTX_mode(const EVP_CIPHER_CTX *ctx);
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);
The EVP cipher routines are a high level interface to certain
symmetric ciphers.
-EVP_EncryptInit() initializes a cipher context B<ctx> for encryption
-with cipher B<type>. B<type> is normally supplied by a function such
-as EVP_des_cbc() . 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_CIPHER_CTX_new() creates a cipher context.
+
+EVP_CIPHER_CTX_free() clears all information from a cipher context
+and free up any allocated memory associate with it, including B<ctx>
+itself. This function should be called after all operations using a
+cipher are complete so sensitive information does not remain in
+memory.
+
+EVP_EncryptInit_ex() sets up cipher context B<ctx> for encryption
+with cipher B<type> from ENGINE B<impl>. B<ctx> must be created
+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>.
-
-EVP_EncryptFinal() 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.
-
-EVP_DecryptInit(), EVP_DecryptUpdate() and EVP_DecryptFinal() are the
+to (inl + cipher_block_size - 1) so B<out> should contain sufficient
+room. The actual number of bytes written is placed in B<outl>. It also
+checks if B<in> and B<out> are partially overlapping, and if they are
+0 is returned to indicate failure.
+
+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 standard block padding (aka PKCS padding) as described in
+the NOTES section, below. 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 the final block is not correctly formatted. The parameters
-and restrictions are identical to the encryption operations except that
-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(), EVP_CipherUpdate() and EVP_CipherFinal() 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.
-It should be called after all operations using a cipher are complete
-so sensitive information does not remain in memory.
+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_reset() clears all information from a cipher context
+and free up any allocated memory associate with it, except the B<ctx>
+itself. This function should be called anytime B<ctx> is to be reused
+for another EVP_CipherInit() / EVP_CipherUpdate() / EVP_CipherFinal()
+series of calls.
+
+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 they also cleaned 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
value is an internal value which may not have a corresponding OBJECT
IDENTIFIER.
+EVP_CIPHER_CTX_set_padding() enables or disables padding. This
+function should be called after the context is set up for encryption
+or decryption with EVP_EncryptInit_ex(), EVP_DecryptInit_ex() or
+EVP_CipherInit_ex(). 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
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
+structure. The constant B<EVP_MAX_BLOCK_LENGTH> is also the maximum block
length for all ciphers.
EVP_CIPHER_type() and EVP_CIPHER_CTX_type() return the type of the passed
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.
+and set.
=head1 RETURN VALUES
-EVP_EncryptInit(), EVP_EncryptUpdate() and EVP_EncryptFinal() return 1 for success
-and 0 for failure.
+EVP_CIPHER_CTX_new() returns a pointer to a newly created
+B<EVP_CIPHER_CTX> for success and B<NULL> for failure.
-EVP_DecryptInit() and EVP_DecryptUpdate() return 1 for success and 0 for failure.
-EVP_DecryptFinal() returns 0 if the decrypt failed or 1 for success.
+EVP_EncryptInit_ex(), EVP_EncryptUpdate() and EVP_EncryptFinal_ex()
+return 1 for success and 0 for failure.
-EVP_CipherInit() and EVP_CipherUpdate() return 1 for success and 0 for failure.
-EVP_CipherFinal() returns 1 for a decryption failure or 1 for success.
+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_CIPHER_CTX_cleanup() returns 1 for success and 0 for failure.
+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_reset() 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_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_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.
+EVP_CIPHER_param_to_asn1() and EVP_CIPHER_asn1_to_param() return greater
+than zero for success and zero or a negative number.
=head1 CIPHER LISTING
Null cipher: does nothing.
-=item EVP_des_cbc(void), EVP_des_ecb(void), EVP_des_cfb(void), EVP_des_ofb(void)
+=item EVP_aes_128_cbc(), EVP_aes_128_ecb(), EVP_aes_128_cfb(), EVP_aes_128_ofb()
+
+AES with a 128-bit key in CBC, ECB, CFB and OFB modes respectively.
+
+=item EVP_aes_192_cbc(), EVP_aes_192_ecb(), EVP_aes_192_cfb(), EVP_aes_192_ofb()
-DES in CBC, ECB, CFB and OFB modes respectively.
+AES with a 192-bit key 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)
+=item EVP_aes_256_cbc(), EVP_aes_256_ecb(), EVP_aes_256_cfb(), EVP_aes_256_ofb()
+
+AES with a 256-bit key in CBC, ECB, CFB and OFB modes respectively.
+
+=item EVP_des_cbc(), EVP_des_ecb(), EVP_des_cfb(), EVP_des_ofb()
+
+DES in CBC, ECB, CFB and OFB modes respectively.
+
+=item EVP_des_ede_cbc(), EVP_des_ede(), EVP_des_ede_ofb(), EVP_des_ede_cfb()
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)
+=item EVP_des_ede3_cbc(), EVP_des_ede3(), EVP_des_ede3_ofb(), EVP_des_ede3_cfb()
Three key triple DES in CBC, ECB, CFB and OFB modes respectively.
-=item EVP_desx_cbc(void)
+=item EVP_desx_cbc()
DESX algorithm in CBC mode.
-=item EVP_rc4(void)
+=item EVP_rc4()
RC4 stream cipher. This is a variable key length cipher with default key length 128 bits.
-=item EVP_rc4_40(void)
+=item EVP_rc4_40()
-RC4 stream cipher with 40 bit key length. This is obsolete and new code should use EVP_rc4()
+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)
+=item EVP_idea_cbc() EVP_idea_ecb(), EVP_idea_cfb(), EVP_idea_ofb()
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)
+=item EVP_rc2_cbc(), EVP_rc2_ecb(), EVP_rc2_cfb(), EVP_rc2_ofb()
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)
+=item EVP_rc2_40_cbc(), EVP_rc2_64_cbc()
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);
+=item EVP_bf_cbc(), EVP_bf_ecb(), EVP_bf_cfb(), EVP_bf_ofb()
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)
+=item EVP_cast5_cbc(), EVP_cast5_ecb(), EVP_cast5_cfb(), EVP_cast5_ofb()
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)
+=item EVP_rc5_32_12_16_cbc(), EVP_rc5_32_12_16_ecb(), EVP_rc5_32_12_16_cfb(), EVP_rc5_32_12_16_ofb()
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.
+=item EVP_aes_128_gcm(), EVP_aes_192_gcm(), EVP_aes_256_gcm()
+
+AES Galois Counter Mode (GCM) for 128, 192 and 256 bit keys respectively.
+These ciphers require additional control operations to function correctly: see
+the L</GCM and OCB Modes> section below for details.
+
+=item EVP_aes_128_ocb(void), EVP_aes_192_ocb(void), EVP_aes_256_ocb(void)
+
+Offset Codebook Mode (OCB) for 128, 192 and 256 bit keys respectively.
+These ciphers require additional control operations to function correctly: see
+the L</GCM and OCB Modes> section below for details.
+
+=item EVP_aes_128_ccm(), EVP_aes_192_ccm(), EVP_aes_256_ccm()
+
+AES Counter with CBC-MAC Mode (CCM) for 128, 192 and 256 bit keys respectively.
+These ciphers require additional control operations to function correctly: see
+CCM mode section below for details.
+
=back
+=head1 GCM and OCB Modes
+
+For GCM and OCB mode ciphers the behaviour of the EVP interface is subtly
+altered and several additional ctrl operations are supported.
+
+To specify any additional authenticated data (AAD) a call to EVP_CipherUpdate(),
+EVP_EncryptUpdate() or EVP_DecryptUpdate() should be made with the output
+parameter B<out> set to B<NULL>.
+
+When decrypting the return value of EVP_DecryptFinal() or EVP_CipherFinal()
+indicates if the operation was successful. If it does not indicate success
+the authentication operation has failed and any output data B<MUST NOT>
+be used as it is corrupted.
+
+The following ctrls are supported in both GCM and OCB modes:
+
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL);
+
+Sets the IV length: this call can only be made before specifying an IV. If
+not called a default IV length is used. For GCM AES and OCB AES the default is
+12 (i.e. 96 bits). For OCB mode the maximum is 15.
+
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen, tag);
+
+Writes B<taglen> bytes of the tag value to the buffer indicated by B<tag>.
+This call can only be made when encrypting data and B<after> all data has been
+processed (e.g. after an EVP_EncryptFinal() call). For OCB mode the taglen must
+either be 16 or the value previously set via EVP_CTRL_OCB_SET_TAGLEN.
+
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen, tag);
+
+Sets the expected tag to B<taglen> bytes from B<tag>. This call is only legal
+when decrypting data and must be made B<before> any data is processed (e.g.
+before any EVP_DecryptUpdate() call). For OCB mode the taglen must
+either be 16 or the value previously set via EVP_CTRL_AEAD_SET_TAG.
+
+In OCB mode calling this with B<tag> set to NULL sets the tag length. The tag
+length can only be set before specifying an IV. If not called a default tag
+length is used. For OCB AES the default is 16 (i.e. 128 bits). This is also the
+maximum tag length for OCB.
+
+See L</EXAMPLES> below for an example of the use of GCM mode.
+
+=head1 CCM Mode
+
+The behaviour of CCM mode ciphers is similar to GCM mode but with a few
+additional requirements and different ctrl values.
+
+Like GCM and OCB modes any additional authenticated data (AAD) is passed by calling
+EVP_CipherUpdate(), EVP_EncryptUpdate() or EVP_DecryptUpdate() with the output
+parameter B<out> set to B<NULL>. Additionally the total plaintext or ciphertext
+length B<MUST> be passed to EVP_CipherUpdate(), EVP_EncryptUpdate() or
+EVP_DecryptUpdate() with the output and input parameters (B<in> and B<out>)
+set to B<NULL> and the length passed in the B<inl> parameter.
+
+The following ctrls are supported in CCM mode:
+
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen, tag);
+
+This call is made to set the expected B<CCM> tag value when decrypting or
+the length of the tag (with the B<tag> parameter set to NULL) when encrypting.
+The tag length is often referred to as B<M>. If not set a default value is
+used (12 for AES).
+
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_L, ivlen, NULL);
+
+Sets the CCM B<L> value. If not set a default is used (8 for AES).
+
+ EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL);
+
+Sets the CCM nonce (IV) length: this call can only be made before specifying
+an nonce value. The nonce length is given by B<15 - L> so it is 7 by default
+for AES.
+
+
+
=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.
+transparent to the cipher used and much more flexible. Additionally, the
+B<EVP> interface will ensure the use of platform specific cryptographic
+acceleration such as AES-NI (the low level interfaces do not provide the
+guarantee).
-PKCS padding works by adding B<n> padding bytes of value B<n> to make the total
+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
When decrypting the final block is checked to see if it has the correct form.
-Although the decryption operation can produce an error, 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.
+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_EncryptUpdate(), EVP_EncryptFinal(),
-EVP_DecryptInit(), EVP_DecryptUpdate(), EVP_CipherInit() and EVP_CipherUpdate()
-and EVP_CIPHER_CTX_cleanup() did not return errors in OpenSSL version 0.9.5a or
-earlier. Software only versions of encryption algorithms will never return
-error codes for these functions, unless there is a programming error (for example
-and attempt to set the key before the cipher is set in EVP_EncryptInit() ).
+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.
-It should be possible to disable PKCS padding: currently it isn't.
-
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
+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
=head1 EXAMPLES
-Get the number of rounds used in RC5:
-
- int nrounds;
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC5_ROUNDS, 0, &i);
+Encrypt a string using IDEA:
+
+ 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};
+ char intext[] = "Some Crypto Text";
+ EVP_CIPHER_CTX ctx;
+ FILE *out;
+
+ ctx = EVP_CIPHER_CTX_new();
+ EVP_EncryptInit_ex(ctx, EVP_idea_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_free(ctx);
+ /* Need binary mode for fopen because encrypted data is
+ * binary data. Also cannot use strlen() on it because
+ * it wont be null terminated and may contain embedded
+ * nulls.
+ */
+ 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 (shown on two lines for clarity):
+
+ openssl idea -d <filename
+ -K 000102030405060708090A0B0C0D0E0F -iv 0102030405060708
+
+General encryption and decryption function example using FILE I/O and AES128
+with a 128-bit key:
+
+ int do_crypt(FILE *in, FILE *out, int do_encrypt)
+ {
+ /* Allow enough space in output buffer for additional block */
+ unsigned char inbuf[1024], outbuf[1024 + EVP_MAX_BLOCK_LENGTH];
+ int inlen, outlen;
+ EVP_CIPHER_CTX *ctx;
+ /* Bogus key and IV: we'd normally set these from
+ * another source.
+ */
+ unsigned char key[] = "0123456789abcdeF";
+ unsigned char iv[] = "1234567887654321";
+
+ /* Don't set key or IV right away; we want to check lengths */
+ ctx = EVP_CIPHER_CTX_new();
+ EVP_CipherInit_ex(&ctx, EVP_aes_128_cbc(), NULL, NULL, NULL,
+ do_encrypt);
+ OPENSSL_assert(EVP_CIPHER_CTX_key_length(ctx) == 16);
+ OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) == 16);
+
+ /* 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_free(ctx);
+ return 0;
+ }
+ fwrite(outbuf, 1, outlen, out);
+ }
+ if(!EVP_CipherFinal_ex(ctx, outbuf, &outlen))
+ {
+ /* Error */
+ EVP_CIPHER_CTX_free(ctx);
+ return 0;
+ }
+ fwrite(outbuf, 1, outlen, out);
+
+ EVP_CIPHER_CTX_free(ctx);
+ return 1;
+ }
-Get the RC2 effective key length:
- int key_bits;
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC2_KEY_BITS, 0, &i);
+=head1 SEE ALSO
-Set the number of rounds used in RC5:
+L<evp(3)>
- int nrounds;
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC5_ROUNDS, i, NULL);
+=head1 HISTORY
-Set the number of rounds used in RC2:
+Support for OCB mode was added in OpenSSL 1.1.0
- int nrounds;
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC2_KEY_BITS, i, NULL);
+B<EVP_CIPHER_CTX> was made opaque in OpenSSL 1.1.0. As a result,
+EVP_CIPHER_CTX_reset() appeared and EVP_CIPHER_CTX_cleanup()
+disappeared. EVP_CIPHER_CTX_init() remains as an alias for
+EVP_CIPHER_CTX_reset().
-=head1 SEE ALSO
+=head1 COPYRIGHT
-L<evp(3)|evp(3)>
+Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
-=head1 HISTORY
+Licensed under the OpenSSL license (the "License"). You may not use
+this file except in compliance with the License. You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
=cut
projects / openssl.git / blobdiff