enc.c

mediastreamer2是开源的网络传输媒体流的库

			goto end;
			}

		/* It must be large enough for a base64 encoded line */
		if (n < 80) n=80;

		bsize=(int)n;
		if (verbose) BIO_printf(bio_err,"bufsize=%d\n",bsize);
		}

	strbuf=OPENSSL_malloc(SIZE);
	buff=(unsigned char *)OPENSSL_malloc(EVP_ENCODE_LENGTH(bsize));
	if ((buff == NULL) || (strbuf == NULL))
		{
		BIO_printf(bio_err,"OPENSSL_malloc failure %ld\n",(long)EVP_ENCODE_LENGTH(bsize));
		goto end;
		}

	in=BIO_new(BIO_s_file());
	out=BIO_new(BIO_s_file());
	if ((in == NULL) || (out == NULL))
		{
		ERR_print_errors(bio_err);
		goto end;
		}
	if (debug)
		{
		BIO_set_callback(in,BIO_debug_callback);
		BIO_set_callback(out,BIO_debug_callback);
		BIO_set_callback_arg(in,bio_err);
		BIO_set_callback_arg(out,bio_err);
		}

	if (inf == NULL)
		BIO_set_fp(in,stdin,BIO_NOCLOSE);
	else
		{
		if (BIO_read_filename(in,inf) <= 0)
			{
			perror(inf);
			goto end;
			}
		}

	if(!str && passarg) {
		if(!app_passwd(bio_err, passarg, NULL, &pass, NULL)) {
			BIO_printf(bio_err, "Error getting password\n");
			goto end;
		}
		str = pass;
	}

	if ((str == NULL) && (cipher != NULL) && (hkey == NULL))
		{
		for (;;)
			{
			char buf[200];

			BIO_snprintf(buf,sizeof buf,"enter %s %s password:",
				     OBJ_nid2ln(EVP_CIPHER_nid(cipher)),
				     (enc)?"encryption":"decryption");
			strbuf[0]='\0';
			i=EVP_read_pw_string((char *)strbuf,SIZE,buf,enc);
			if (i == 0)
				{
				if (strbuf[0] == '\0')
					{
					ret=1;
					goto end;
					}
				str=strbuf;
				break;
				}
			if (i < 0)
				{
				BIO_printf(bio_err,"bad password read\n");
				goto end;
				}
			}
		}


	if (outf == NULL)
		{
		BIO_set_fp(out,stdout,BIO_NOCLOSE);
#ifdef OPENSSL_SYS_VMS
		{
		BIO *tmpbio = BIO_new(BIO_f_linebuffer());
		out = BIO_push(tmpbio, out);
		}
#endif
		}
	else
		{
		if (BIO_write_filename(out,outf) <= 0)
			{
			perror(outf);
			goto end;
			}
		}

	rbio=in;
	wbio=out;

	if (base64)
		{
		if ((b64=BIO_new(BIO_f_base64())) == NULL)
			goto end;
		if (debug)
			{
			BIO_set_callback(b64,BIO_debug_callback);
			BIO_set_callback_arg(b64,bio_err);
			}
		if (olb64)
			BIO_set_flags(b64,BIO_FLAGS_BASE64_NO_NL);
		if (enc)
			wbio=BIO_push(b64,wbio);
		else
			rbio=BIO_push(b64,rbio);
		}

	if (cipher != NULL)
		{
		/* Note that str is NULL if a key was passed on the command
		 * line, so we get no salt in that case. Is this a bug?
		 */
		if (str != NULL)
			{
			/* Salt handling: if encrypting generate a salt and
			 * write to output BIO. If decrypting read salt from
			 * input BIO.
			 */
			unsigned char *sptr;
			if(nosalt) sptr = NULL;
			else {
				if(enc) {
					if(hsalt) {
						if(!set_hex(hsalt,salt,sizeof salt)) {
							BIO_printf(bio_err,
								"invalid hex salt value\n");
							goto end;
						}
					} else if (RAND_pseudo_bytes(salt, sizeof salt) < 0)
						goto end;
					/* If -P option then don't bother writing */
					if((printkey != 2)
					   && (BIO_write(wbio,magic,
							 sizeof magic-1) != sizeof magic-1
					       || BIO_write(wbio,
							    (char *)salt,
							    sizeof salt) != sizeof salt)) {
						BIO_printf(bio_err,"error writing output file\n");
						goto end;
					}
				} else if(BIO_read(rbio,mbuf,sizeof mbuf) != sizeof mbuf
					  || BIO_read(rbio,
						      (unsigned char *)salt,
				    sizeof salt) != sizeof salt) {
					BIO_printf(bio_err,"error reading input file\n");
					goto end;
				} else if(memcmp(mbuf,magic,sizeof magic-1)) {
				    BIO_printf(bio_err,"bad magic number\n");
				    goto end;
				}

				sptr = salt;
			}

			EVP_BytesToKey(cipher,dgst,sptr,
				(unsigned char *)str,
				strlen(str),1,key,iv);
			/* zero the complete buffer or the string
			 * passed from the command line
			 * bug picked up by
			 * Larry J. Hughes Jr. <[e-mail]> */
			if (str == strbuf)
				OPENSSL_cleanse(str,SIZE);
			else
				OPENSSL_cleanse(str,strlen(str));
			}
		if ((hiv != NULL) && !set_hex(hiv,iv,sizeof iv))
			{
			BIO_printf(bio_err,"invalid hex iv value\n");
			goto end;
			}
		if ((hiv == NULL) && (str == NULL))
			{
			/* No IV was explicitly set and no IV was generated
			 * during EVP_BytesToKey. Hence the IV is undefined,
			 * making correct decryption impossible. */
			BIO_printf(bio_err, "iv undefined\n");
			goto end;
			}
		if ((hkey != NULL) && !set_hex(hkey,key,sizeof key))
			{
			BIO_printf(bio_err,"invalid hex key value\n");
			goto end;
			}

		if ((benc=BIO_new(BIO_f_cipher())) == NULL)
			goto end;

		/* Since we may be changing parameters work on the encryption
		 * context rather than calling BIO_set_cipher().
		 */

		BIO_get_cipher_ctx(benc, &ctx);
		if (!EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, enc))
			{
			BIO_printf(bio_err, "Error setting cipher %s\n",
				EVP_CIPHER_name(cipher));
			ERR_print_errors(bio_err);
			goto end;
			}

		if (nopad)
			EVP_CIPHER_CTX_set_padding(ctx, 0);

		if (!EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, enc))
			{
			BIO_printf(bio_err, "Error setting cipher %s\n",
				EVP_CIPHER_name(cipher));
			ERR_print_errors(bio_err);
			goto end;
			}

		if (debug)
			{
			BIO_set_callback(benc,BIO_debug_callback);
			BIO_set_callback_arg(benc,bio_err);
			}

		if (printkey)
			{
			if (!nosalt)
				{
				printf("salt=");
				for (i=0; i<(int)sizeof(salt); i++)
					printf("%02X",salt[i]);
				printf("\n");
				}
			if (cipher->key_len > 0)
				{
				printf("key=");
				for (i=0; i<cipher->key_len; i++)
					printf("%02X",key[i]);
				printf("\n");
				}
			if (cipher->iv_len > 0)
				{
				printf("iv =");
				for (i=0; i<cipher->iv_len; i++)
					printf("%02X",iv[i]);
				printf("\n");
				}
			if (printkey == 2)
				{
				ret=0;
				goto end;
				}
			}
		}

	/* Only encrypt/decrypt as we write the file */
	if (benc != NULL)
		wbio=BIO_push(benc,wbio);

	for (;;)
		{
		inl=BIO_read(rbio,(char *)buff,bsize);
		if (inl <= 0) break;
		if (BIO_write(wbio,(char *)buff,inl) != inl)
			{
			BIO_printf(bio_err,"error writing output file\n");
			goto end;
			}
		}
	if (!BIO_flush(wbio))
		{
		BIO_printf(bio_err,"bad decrypt\n");
		goto end;
		}

	ret=0;
	if (verbose)
		{
		BIO_printf(bio_err,"bytes read   :%8ld\n",BIO_number_read(in));
		BIO_printf(bio_err,"bytes written:%8ld\n",BIO_number_written(out));
		}
end:
	ERR_print_errors(bio_err);
	if (strbuf != NULL) OPENSSL_free(strbuf);
	if (buff != NULL) OPENSSL_free(buff);
	if (in != NULL) BIO_free(in);
	if (out != NULL) BIO_free_all(out);
	if (benc != NULL) BIO_free(benc);
	if (b64 != NULL) BIO_free(b64);
	if(pass) OPENSSL_free(pass);
	apps_shutdown();
	OPENSSL_EXIT(ret);
	}

int set_hex(char *in, unsigned char *out, int size)
	{
	int i,n;
	unsigned char j;

	n=strlen(in);
	if (n > (size*2))
		{
		BIO_printf(bio_err,"hex string is too long\n");
		return(0);
		}
	memset(out,0,size);
	for (i=0; i<n; i++)
		{
		j=(unsigned char)*in;
		*(in++)='\0';
		if (j == 0) break;
		if ((j >= '0') && (j <= '9'))
			j-='0';
		else if ((j >= 'A') && (j <= 'F'))
			j=j-'A'+10;
		else if ((j >= 'a') && (j <= 'f'))
			j=j-'a'+10;
		else
			{
			BIO_printf(bio_err,"non-hex digit\n");
			return(0);
			}
		if (i&1)
			out[i/2]|=j;
		else
			out[i/2]=(j<<4);
		}
	return(1);
	}