EVP_get_cipherbyobj,
EVP_CIPHER_is_a,
EVP_CIPHER_name,
+EVP_CIPHER_number,
EVP_CIPHER_names_do_all,
EVP_CIPHER_provider,
EVP_CIPHER_nid,
const EVP_CIPHER *EVP_get_cipherbyobj(const ASN1_OBJECT *a);
int EVP_CIPHER_nid(const EVP_CIPHER *e);
+ int EVP_CIPHER_number(const EVP_CIPHER *e);
int EVP_CIPHER_is_a(const EVP_CIPHER *cipher, const char *name);
void EVP_CIPHER_names_do_all(const EVP_CIPHER *cipher,
void (*fn)(const char *name, void *data),
=head1 DESCRIPTION
-The EVP cipher routines are a high level interface to certain
+The EVP cipher routines are a high-level interface to certain
symmetric ciphers.
The B<EVP_CIPHER> type is a structure for cipher method implementation.
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<out> should contain sufficient
-room. The actual number of bytes written is placed in B<outl>. It also
+of data written depends on the block alignment of the encrypted data.
+For most ciphers and modes, the amount of data written can be anything
+from zero bytes to (inl + cipher_block_size - 1) bytes.
+For wrap cipher modes, the amount of data written can be anything
+from zero bytes to (inl + cipher_block_size) bytes.
+For stream ciphers, the amount of data written can be anything from zero
+bytes to inl bytes.
+Thus, B<out> should contain sufficient room for the operation being performed.
+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.
EVP_CIPHER_gettable_params(), EVP_CIPHER_gettable_ctx_params(), and
EVP_CIPHER_settable_ctx_params() get a constant B<OSSL_PARAM> array
-that decribes the retrievable and settable parameters, i.e. parameters
+that describes the retrievable and settable parameters, i.e. parameters
that can be used with EVP_CIPHER_get_params(), EVP_CIPHER_CTX_get_params()
and EVP_CIPHER_CTX_set_params(), respectively.
See L<OSSL_PARAM(3)> for the use of B<OSSL_PARAM> as parameter descriptor.
EVP_CIPHER_is_a() returns 1 if I<cipher> is an implementation of an
algorithm that's identifiable with I<name>, otherwise 0.
+If I<cipher> is a legacy cipher (it's the return value from the likes
+of EVP_aes128() rather than the result of an EVP_CIPHER_fetch()), only
+cipher names registered with the default library context (see
+L<OPENSSL_CTX(3)>) will be considered.
+
+EVP_CIPHER_number() returns the internal dynamic number assigned to
+the I<cipher>. This is only useful with fetched B<EVP_CIPHER>s.
EVP_CIPHER_name() and EVP_CIPHER_CTX_name() return the name of the passed
cipher or context. For fetched ciphers with multiple names, only one
All algorithms have a fixed key length unless otherwise stated.
-Refer to L<SEE ALSO> for the full list of ciphers available through the EVP
+Refer to L</SEE ALSO> for the full list of ciphers available through the EVP
interface.
=over 4
=item 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
+Sets the CCM nonce (IV) length. This call can only be made before specifying a
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
+preference to the low-level interfaces. This is because the code then becomes
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
+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
EVP_CipherInit_ex() and EVP_CipherFinal_ex() because they can reuse an
existing context without allocating and freeing it up on each call.
+There are some differences between functions EVP_CipherInit() and
+EVP_CipherInit_ex(), significant in some circumstances. EVP_CipherInit() fills
+the passed context object with zeros. As a consequence, EVP_CipherInit() does
+not allow step-by-step initialization of the ctx when the I<key> and I<iv> are
+passed in separate calls. It also means that the flags set for the CTX are
+removed, and it is especially important for the
+B<EVP_CIPHER_CTX_FLAG_WRAP_ALLOW> flag treated specially in
+EVP_CipherInit_ex().
+
EVP_get_cipherbynid(), and EVP_get_cipherbyobj() are implemented as macros.
=head1 BUGS
/* 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,
+ 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);
return 1;
}
+Encryption using AES-CBC with a 256-bit key with "CS1" ciphertext stealing.
+
+ int encrypt(const unsigned char *key, const unsigned char *iv,
+ const unsigned char *msg, size_t msg_len, unsigned char *out)
+ {
+ /*
+ * This assumes that key size is 32 bytes and the iv is 16 bytes.
+ * For ciphertext stealing mode the length of the ciphertext "out" will be
+ * the same size as the plaintext size "msg_len".
+ * The "msg_len" can be any size >= 16.
+ */
+ int ret = 0, encrypt = 1, outlen, len;
+ EVP_CIPHER_CTX *ctx = NULL;
+ EVP_CIPHER *cipher = NULL;
+ OSSL_PARAM params[2];
+
+ ctx = EVP_CIPHER_CTX_new();
+ cipher = EVP_CIPHER_fetch(NULL, "AES-256-CBC-CTS", NULL);
+ if (ctx == NULL || cipher == NULL)
+ goto err;
+
+ if (!EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, encrypt))
+ goto err;
+ /*
+ * The default is "CS1" so this is not really needed,
+ * but would be needed to set either "CS2" or "CS3".
+ */
+ params[0] = OSSL_PARAM_construct_utf8_string(OSSL_CIPHER_PARAM_CTS_MODE,
+ "CS1", 0);
+ params[1] = OSSL_PARAM_construct_end();
+ if (!EVP_CIPHER_CTX_set_params(ctx, params))
+ goto err;
+
+ /* NOTE: CTS mode does not support multiple calls to EVP_CipherUpdate() */
+ if (!EVP_CipherUpdate(ctx, encrypted, &outlen, msg, msglen))
+ goto err;
+ if (!EVP_CipherFinal_ex(ctx, encrypted + outlen, &len))
+ goto err;
+ ret = 1;
+ err:
+ EVP_CIPHER_free(cipher);
+ EVP_CIPHER_CTX_free(ctx);
+ return ret;
+ }
=head1 SEE ALSO
Supported ciphers are listed in:
-L<EVP_aes(3)>,
-L<EVP_aria(3)>,
-L<EVP_bf(3)>,
-L<EVP_camellia(3)>,
-L<EVP_cast5(3)>,
+L<EVP_aes_128_gcm(3)>,
+L<EVP_aria_128_gcm(3)>,
+L<EVP_bf_cbc(3)>,
+L<EVP_camellia_128_ecb(3)>,
+L<EVP_cast5_cbc(3)>,
L<EVP_chacha20(3)>,
-L<EVP_des(3)>,
-L<EVP_desx(3)>,
-L<EVP_idea(3)>,
-L<EVP_rc2(3)>,
+L<EVP_des_cbc(3)>,
+L<EVP_desx_cbc(3)>,
+L<EVP_idea_cbc(3)>,
+L<EVP_rc2_cbc(3)>,
L<EVP_rc4(3)>,
-L<EVP_rc5(3)>,
-L<EVP_seed(3)>,
-L<EVP_sm4(3)>
+L<EVP_rc5_32_12_16_cbc(3)>,
+L<EVP_seed_cbc(3)>,
+L<EVP_sm4_cbc(3)>
=head1 HISTORY
=head1 COPYRIGHT
-Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
projects / openssl.git / blobdiff