Commit fd4592be authored by Jan Schaumann's avatar Jan Schaumann Committed by Rich Salz
Browse files

RT1804: fix EXAMPLE in EVP_EncryptInit.pod 



The EXAMPLE that used FILE and RC2 doesn't compile due to a
few minor errors.  Tweak to use IDEA and AES-128. Remove
examples about RC2 and RC5.

Reviewed-by: default avatarEmilia Kasper <emilia@openssl.org>
parent 2dd8cb3b

doc/crypto/EVP_EncryptInit.pod

+23 −33
Original line number Diff line number Diff line
@@ -477,27 +477,7 @@ 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:

Encrypt a string using IDEA:



 int do_crypt(char *outfile)

 	{
@@ -511,8 +491,9 @@ Encrypt a string using blowfish: 
	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);

	EVP_EncryptInit_ex(&ctx, EVP_idea_cbc(), NULL, key, iv);



	if(!EVP_EncryptUpdate(&ctx, outbuf, &outlen, intext, strlen(intext)))

		{
@@ -541,28 +522,34 @@ Encrypt a string using blowfish: 
	}



The ciphertext from the above example can be decrypted using the B<openssl>

utility with the command line:

utility with the command line (shown on two lines for clarity):

 

 S<openssl bf -in cipher.bin -K 000102030405060708090A0B0C0D0E0F -iv 0102030405060708 -d>

 openssl idea -d <filename

          -K 000102030405060708090A0B0C0D0E0F -iv 0102030405060708



General encryption, decryption function example using FILE I/O and RC2 with an

80 bit key:

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 */

	inbuf[1024], outbuf[1024 + EVP_MAX_BLOCK_LENGTH];

	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[] = "0123456789";

	unsigned char iv[] = "12345678";

	/* Don't set key or IV because we will modify the parameters */

	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_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, 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(;;)
@@ -601,4 +588,7 @@ EVP_DecryptInit_ex(), EVP_DecryptFinal_ex(), EVP_CipherInit_ex(), 
EVP_CipherFinal_ex() and EVP_CIPHER_CTX_set_padding() appeared in

OpenSSL 0.9.7.



IDEA appeared in OpenSSL 0.9.7 but was often disabled due to

patent concerns; the last patents expired in 2012.



=cut