OpenSSL EVP_EncryptInit(3openssl)
NNNNAAAAMMMMEEEEEVP_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 cipher routines
SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS#include
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);15/Apr/2005 Last change: 0.9.8o 1
OpenSSL EVP_EncryptInit(3openssl)
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);
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN The EVP cipher routines are a high level interface to certain symmetric ciphers.EVP_CIPHER_CTX_init() initializes cipher contex ccccttttxxxx.
EVP_EncryptInit_ex() sets up cipher context ccccttttxxxx for
encryption with cipher ttttyyyyppppeeee from ENGINE iiiimmmmppppllll. ccccttttxxxx must be initialized before calling this function. ttttyyyyppppeeee is normallysupplied by a function such as EVP_des_cbc(). If iiiimmmmppppllll is
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OpenSSL EVP_EncryptInit(3openssl)
NULL then the default implementation is used. kkkkeeeeyyyy is the symmetric key to use and iiiivvvv 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 ttttyyyyppppeeee in an initial call and supply the remaining parameters in subsequent calls, all of which have ttttyyyyppppeeee set to NULL. This is done when the default cipher parameters are not appropriate.EVP_EncryptUpdate() encrypts iiiinnnnllll bytes from the buffer iiiinnnn
and writes the encrypted version to oooouuuutttt. 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 oooouuuuttttllll should contain sufficient
room. The actual number of bytes written is placed in oooouuuuttttllll. If padding is enabled (the default) thenEVP_EncryptFinal_ex() encrypts the "final" data, that is any
data that remains in a partial block. It uses standard block padding (aka PKCS padding). The encrypted final data is written to oooouuuutttt which should have sufficient space for one cipher block. The number of bytes written is placed in oooouuuuttttllll. After this function is called the encryption operation isfinished 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 enabledthe decrypted data buffer oooouuuutttt passed to EVP_DecryptUpdate()
should have sufficient room for (iiiinnnnllll + cipher_block_size)
bytes unless the cipher block size is 1 in which case iiiinnnnllll 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 eeeennnncccc parameter. It should be set to 1 forencryption, 0 for decryption and -1 to leave the value
unchanged (the actual value of 'enc' being supplied in a previous call).15/Apr/2005 Last change: 0.9.8o 3
OpenSSL EVP_EncryptInit(3openssl)
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 ccccttttxxxx
paramter does not need to be initialized and they always use the default cipher implementation.EVP_EncryptFinal(), EVP_DecryptFinal() and EVP_CipherFinal()
behave in a similar way to EVP_EncryptFinal_ex(),
EVP_DecryptFinal_ex() and EVP_CipherFinal_ex() except ccccttttxxxx is
automatically cleaned up after the call.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 EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR or EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR_CCCCTTTTXXXX
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 ppppaaaadddd 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 EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR
or EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR_CCCCTTTTXXXX structure. The constant EEEEVVVVPPPP_MMMMAAAAXXXX_KKKKEEEEYYYY_LLLLEEEENNNNGGGGTTTTHHHH
is the maximum key length for all ciphers. Note: althoughEVP_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 EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR or
EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR_CCCCTTTTXXXX. It will return zero if the cipher does not
use an IV. The constant EEEEVVVVPPPP_MMMMAAAAXXXX_IIIIVVVV_LLLLEEEENNNNGGGGTTTTHHHH is the maximum IV
length for all ciphers.15/Apr/2005 Last change: 0.9.8o 4
OpenSSL EVP_EncryptInit(3openssl)
EVP_CIPHER_block_size() and EVP_CIPHER_CTX_block_size()
return the block size of a cipher when passed an EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR
or EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR_CCCCTTTTXXXX structure. The constant EEEEVVVVPPPP_MMMMAAAAXXXX_IIIIVVVV_LLLLEEEENNNNGGGGTTTTHHHH
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 returnNNNNIIIIDDDD_uuuunnnnddddeeeeffff.
EVP_CIPHER_CTX_cipher() returns the EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR structure
when passed an EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR_CCCCTTTTXXXX 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 anyEVP_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 setbut 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. RRRREEEETTTTUUUURRRRNNNN VVVVAAAALLLLUUUUEEEESSSSEVP_EncryptInit_ex(), EVP_EncryptUpdate() and
EVP_EncryptFinal_ex() return 1 for success and 0 for
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OpenSSL EVP_EncryptInit(3openssl)
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 EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR 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 EEEEVVVVPPPP_CCCCIIIIPPPPHHHHEEEERRRR structure.
EVP_CIPHER_param_to_asn1() and EVP_CIPHER_asn1_to_param()
return 1 for success or zero for failure. CCCCIIIIPPPPHHHHEEEERRRR LLLLIIIISSSSTTTTIIIINNNNGGGG All algorithms have a fixed key length unless otherwise stated.EVP_enc_null()
Null cipher: does nothing.EVP_des_ofb(void)
EVP_des_cbc(void), EVP_des_ecb(void), EVP_des_cfb(void),
DES in CBC, ECB, CFB and OFB modes respectively.EVP_des_ede_cfb(void)
EVP_des_ede_cbc(void), EVP_des_ede(), EVP_des_ede_ofb(void),
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OpenSSL EVP_EncryptInit(3openssl)
Two key triple DES in CBC, ECB, CFB and OFB modes respectively.EVP_des_ede3_cfb(void)
EVP_des_ede3_cbc(void), EVP_des_ede3(), EVP_des_ede3_ofb(void),
Three key triple DES in CBC, ECB, CFB and OFB modes respectively.EVP_desx_cbc(void)
DESX algorithm in CBC mode.EVP_rc4(void)
RC4 stream cipher. This is a variable key length cipher with default key length 128 bits.EVP_rc4_40(void)
RC4 stream cipher with 40 bit key length. This isobsolete and new code should use EVP_rc4() and the
EVP_CIPHER_CTX_set_key_length() function.
EVP_idea_ofb(void), EVP_idea_cbc(void)
EVP_idea_cbc() EVP_idea_ecb(void), EVP_idea_cfb(void),
IDEA encryption algorithm in CBC, ECB, CFB and OFB modes respectively.EVP_rc2_ofb(void)
EVP_rc2_cbc(void), EVP_rc2_ecb(void), EVP_rc2_cfb(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.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 areobsolete 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.EVP_bf_ofb(void);
EVP_bf_cbc(void), EVP_bf_ecb(void), EVP_bf_cfb(void),
Blowfish encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is a variable key length cipher.EVP_cast5_ofb(void)
EVP_cast5_cbc(void), EVP_cast5_ecb(void), EVP_cast5_cfb(void),
CAST encryption algorithm in CBC, ECB, CFB and OFB modes respectively. This is a variable key length cipher.15/Apr/2005 Last change: 0.9.8o 7
OpenSSL EVP_EncryptInit(3openssl)
EVP_rc5_32_12_16_cfb(void), EVP_rc5_32_12_16_ofb(void)
EVP_rc5_32_12_16_cbc(void), EVP_rc5_32_12_16_ecb(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. NNNNOOOOTTTTEEEESSSS Where possible the EEEEVVVVPPPP 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 nnnn padding bytes of value nnnn 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 nnnn 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 withexisting 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. BBBBUUUUGGGGSSSS 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 generic15/Apr/2005 Last change: 0.9.8o 8
OpenSSL EVP_EncryptInit(3openssl)
key as a fixed unsigned char array containingEVP_MAX_KEY_LENGTH bytes.
The ASN1 code is incomplete (and sometimes inaccurate) ithas only been tested for certain common S/MIME ciphers (RC2, DES, triple DES) in CBC mode. EEEEXXXXAAAAMMMMPPPPLLLLEEEESSSS 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}; 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);
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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 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 ooooppppeeeennnnssssssssllll utility with the command line:openssl bf -in cipher.bin -K 000102030405060708090A0B0C0D0E0F -iv 0102030405060708 -d
General encryption, decryption function example using FILEI/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);
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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; } SSSSEEEEEEEE AAAALLLLSSSSOOOO evp(3) HHHHIIIISSSSTTTTOOOORRRRYYYYEVP_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 0.9.7.15/Apr/2005 Last change: 0.9.8o 11
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15/Apr/2005 Last change: 0.9.8o 12