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: Emilia Kasper <emilia@openssl.org>

diff --git a/doc/crypto/EVP_EncryptInit.pod b/doc/crypto/EVP_EncryptInit.pod
index 8d7636c7883a7eec23be0daf1fa7d2e0d471fc39..526447c0a61749961821c030a4f1c1cea9bd1eb4 100644 (file)
--- a/doc/crypto/EVP_EncryptInit.pod
+++ b/doc/crypto/EVP_EncryptInit.pod
@@ -476,27 +476,7 @@ 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)
        {
@@ -510,8 +490,9 @@ 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)))
                {
@@ -540,28 +521,34 @@ 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(;;) 
@@ -600,4 +587,7 @@ 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