=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_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_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>
- void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *a);
+ 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);
+ 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);
+ 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 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_CIPHER_CTX_init() initializes cipher contex B<ctx>.
+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 initialized
+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_des_cbc(). If B<impl> is NULL then the
+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
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>.
+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 L<standard block padding|/NOTES> (aka PKCS padding). The encrypted
+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
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_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
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_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>
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
=head1 RETURN VALUES
+EVP_CIPHER_CTX_new() returns a pointer to a newly created
+B<EVP_CIPHER_CTX> for success and B<NULL> for failure.
+
EVP_EncryptInit_ex(), EVP_EncryptUpdate() and EVP_EncryptFinal_ex()
return 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_cleanup() returns 1 for success and 0 for failure.
+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_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
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.
+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)
-Offest Codebook Mode (OCB) for 128, 192 and 256 bit keys respectively.
+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.
+the L</GCM and OCB Modes> section below for details.
=item EVP_aes_128_ccm(), EVP_aes_192_ccm(), EVP_aes_256_ccm()
the authentication operation has failed and any output data B<MUST NOT>
be used as it is corrupted.
-The following ctrl is supported in OCB mode only:
-
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_OCB_SET_TAGLEN, taglen, NULL);
-
-Sets the tag length: this call can only be made 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.
-
The following ctrls are supported in both GCM and OCB modes:
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_IVLEN, ivlen, NULL);
+ 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_GET_TAG, taglen, tag);
+ 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_SET_TAG, taglen, tag);
+ 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_OCB_SET_TAGLEN.
+either be 16 or the value previously set via EVP_CTRL_AEAD_SET_TAG.
-See L<EXAMPLES> below for an example of the use of GCM mode.
+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 CCM mode but with a few
+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
The following ctrls are supported in CCM mode:
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_TAG, taglen, tag);
+ 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.
Sets the CCM B<L> value. If not set a default is used (8 for AES).
- EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_IVLEN, ivlen, NULL);
+ 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
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;
-
- EVP_CIPHER_CTX_init(&ctx);
- 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_cleanup(&ctx);
- /* Need binary mode for fopen because encrypted data is
- * binary data. Also cannot use strlen() on it because
+ {
+ 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;
- }
+ * 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):
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 */
- EVP_CIPHER_CTX_init(&ctx);
- 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_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;
- }
+ {
+ /* 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;
+ }
=head1 SEE ALSO
-L<evp(3)|evp(3)>
+L<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.
+Support for OCB mode was added in OpenSSL 1.1.0
-IDEA appeared in OpenSSL 0.9.7 but was often disabled due to
-patent concerns; the last patents expired in 2012.
+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 COPYRIGHT
+
+Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+
+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>.
-Support for OCB mode was added in OpenSSL 1.1.0
=cut
projects / openssl.git / blobdiff