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Diffstat (limited to 'Build/source/texk/dvipdfm-x/xsrc/pdfencrypt.c')
-rw-r--r-- | Build/source/texk/dvipdfm-x/xsrc/pdfencrypt.c | 539 |
1 files changed, 0 insertions, 539 deletions
diff --git a/Build/source/texk/dvipdfm-x/xsrc/pdfencrypt.c b/Build/source/texk/dvipdfm-x/xsrc/pdfencrypt.c deleted file mode 100644 index 8e3bf625c53..00000000000 --- a/Build/source/texk/dvipdfm-x/xsrc/pdfencrypt.c +++ /dev/null @@ -1,539 +0,0 @@ -/* - - This is dvipdfmx, an eXtended version of dvipdfm by Mark A. Wicks. - - Copyright (C) 2002-2012 by Jin-Hwan Cho and Shunsaku Hirata, - the dvipdfmx project team. - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. -*/ - -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <time.h> - -#ifdef WIN32 -#include <conio.h> -#define getch _getch -#else /* !WIN32 */ -#include <unistd.h> -#endif /* WIN32 */ - -#include "system.h" -#include "mem.h" -#include "error.h" -#include "pdfobj.h" -#include "dpxcrypt.h" - -#include "pdfencrypt.h" - -#define MAX_KEY_LEN 16 -#define MAX_STR_LEN 32 - -static unsigned char algorithm, revision, key_size; -static unsigned long permission; - -static unsigned char key_data[MAX_KEY_LEN], id_string[MAX_KEY_LEN]; -static unsigned char opwd_string[MAX_STR_LEN], upwd_string[MAX_STR_LEN]; - -static unsigned long current_label = 0; -static unsigned current_generation = 0; - -static ARC4_KEY key; -static MD5_CONTEXT md5_ctx; - -static unsigned char md5_buf[MAX_KEY_LEN], key_buf[MAX_KEY_LEN]; -static unsigned char in_buf[MAX_STR_LEN], out_buf[MAX_STR_LEN]; - -static const unsigned char padding_string[MAX_STR_LEN] = { - 0x28, 0xbf, 0x4e, 0x5e, 0x4e, 0x75, 0x8a, 0x41, - 0x64, 0x00, 0x4e, 0x56, 0xff, 0xfa, 0x01, 0x08, - 0x2e, 0x2e, 0x00, 0xb6, 0xd0, 0x68, 0x3e, 0x80, - 0x2f, 0x0c, 0xa9, 0xfe, 0x64, 0x53, 0x69, 0x7a -}; - -static char owner_passwd[MAX_PWD_LEN], user_passwd[MAX_PWD_LEN]; - -static unsigned char verbose = 0; - -void pdf_enc_set_verbose (void) -{ - if (verbose < 255) verbose++; -} - -#define PRODUCER "%s-%s, Copyright \251 2002-2010 by Jin-Hwan Cho, Matthias Franz, and Shunsaku Hirata" -void pdf_enc_compute_id_string (char *dviname, char *pdfname) -{ - char *date_string, *producer; - time_t current_time; - struct tm *bd_time; - - MD5_init(&md5_ctx); - - date_string = NEW (15, char); - time(¤t_time); - bd_time = localtime(¤t_time); - sprintf (date_string, "%04d%02d%02d%02d%02d%02d", - bd_time -> tm_year+1900, bd_time -> tm_mon+1, bd_time -> tm_mday, - bd_time -> tm_hour, bd_time -> tm_min, bd_time -> tm_sec); - MD5_write(&md5_ctx, (unsigned char *)date_string, strlen(date_string)); - RELEASE (date_string); - - producer = NEW (strlen(PRODUCER)+strlen(PACKAGE)+strlen(VERSION), char); - sprintf(producer, PRODUCER, PACKAGE, VERSION); - MD5_write(&md5_ctx, (unsigned char *)producer, strlen(producer)); - RELEASE (producer); - - if (dviname) - MD5_write(&md5_ctx, (unsigned char *)dviname, strlen(dviname)); - if (pdfname) - MD5_write(&md5_ctx, (unsigned char *)pdfname, strlen(pdfname)); - MD5_final(id_string, &md5_ctx); -} - -static void passwd_padding (unsigned char *src, unsigned char *dst) -{ - register int len = strlen((char *)src); - - if (len > MAX_STR_LEN) - len = MAX_STR_LEN; - - memcpy(dst, src, len); - memcpy(dst+len, padding_string, MAX_STR_LEN-len); -} - -static void compute_owner_password (void) -{ - register unsigned char i, j; - /* - * Algorithm 3.3 Computing the encryption dictionary's O (owner password) - * value - * - * 1. Pad or truncate the owner password string as described in step 1 - * of Algorithm 3.2. If there is no owner password, use the user - * password instead. (See implementation note 17 in Appendix H.) - */ - passwd_padding((unsigned char *)(strlen(owner_passwd) > 0 ? owner_passwd : user_passwd), in_buf); - /* - * 2. Initialize the MD5 hash function and pass the result of step 1 - * as input to this function. - */ - MD5_init(&md5_ctx); - MD5_write(&md5_ctx, in_buf, MAX_STR_LEN); - MD5_final(md5_buf, &md5_ctx); - /* - * 3. (Revision 3 only) Do the following 50 times: Take the output - * from the previous MD5 hash and pass it as input into a new - * MD5 hash. - */ - if (revision == 3) - for (i = 0; i < 50; i++) { - /* - * NOTE: We truncate each MD5 hash as in the following step. - * Otherwise Adobe Reader won't decrypt the PDF file. - */ - MD5_init(&md5_ctx); - MD5_write(&md5_ctx, md5_buf, key_size); - MD5_final(md5_buf, &md5_ctx); - } - /* - * 4. Create an RC4 encryption key using the first n bytes of the output - * from the final MD5 hash, where n is always 5 for revision 2 but - * for revision 3 depends on the value of the encryption dictionary's - * Length entry. - */ - ARC4_set_key(&key, key_size, md5_buf); - /* - * 5. Pad or truncate the user password string as described in step 1 - * of Algorithm 3.2. - */ - passwd_padding((unsigned char *)user_passwd, in_buf); - /* - * 6. Encrypt the result of step 5, using an RC4 encryption function - * with the encryption key obtained in step 4. - */ - ARC4(&key, MAX_STR_LEN, in_buf, out_buf); - /* - * 7. (Revision 3 only) Do the following 19 times: Take the output - * from the previous invocation of the RC4 function and pass it - * as input to a new invocation of the function; use an encryption - * key generated by taking each byte of the encryption key obtained - * in step 4 and performing an XOR (exclusive or) operation between - * that byte and the single-byte value of the iteration counter - * (from 1 to 19). - */ - if (revision == 3) - for (i = 1; i <= 19; i++) { - memcpy(in_buf, out_buf, MAX_STR_LEN); - for (j = 0; j < key_size; j++) - key_buf[j] = md5_buf[j] ^ i; - ARC4_set_key(&key, key_size, key_buf); - ARC4(&key, MAX_STR_LEN, in_buf, out_buf); - } - /* - * 8. Store the output from the final invocation of the RC4 function - * as the value of the O entry in the encryption dictionary. - */ - memcpy(opwd_string, out_buf, MAX_STR_LEN); -} - -static void compute_encryption_key (unsigned char *pwd) -{ - register unsigned char i; - /* - * Algorithm 3.2 Computing an encryption key - * - * 1. Pad or truncate the password string to exactly 32 bytes. If the - * password string is more than 32 bytes long, use only its first - * 32 bytes; if it is less than 32 bytes long, pad it by appending - * the required number of additional bytes from the beginning of - * the following padding string: - * - * < 28 BF 4E 5E 4E 75 8A 41 64 00 4E 56 FF FA 01 08 - * 2E 2E 00 B6 D0 68 3E 80 2F 0C A9 FE 64 53 69 7A > - * - * That is, if the password string is n bytes long, append the - * first 32 - n bytes of the padding string to the end of the - * password string. If the password string is empty (zero-length), - * meaning there is no user password, substitute the entire - * padding string in its place. - */ - passwd_padding(pwd, in_buf); - /* - * 2. Initialize the MD5 hash function and pass the result of step 1 - * as input to this fuction. - */ - MD5_init(&md5_ctx); - MD5_write(&md5_ctx, in_buf, MAX_STR_LEN); - /* - * 3. Pass the value of the encryption dictionary's O entry to the - * MD5 hash function. (Algorithm 3.3 shows how the O value is - * computed.) - */ - MD5_write(&md5_ctx, opwd_string, MAX_STR_LEN); - /* - * 4. Treat the value of the P entry as an unsigned 4-byte integer - * and pass these bytes to the MD5 hash function, low-order byte - * first. - */ - in_buf[0] = (unsigned char)(permission) & 0xFF; - in_buf[1] = (unsigned char)(permission >> 8) & 0xFF; - in_buf[2] = (unsigned char)(permission >> 16) & 0xFF; - in_buf[3] = (unsigned char)(permission >> 24) & 0xFF; - MD5_write(&md5_ctx, in_buf, 4); - /* - * 5. Pass the first element of the file's file identifier array - * (the value of the ID entry in the document's trailer dictionary; - * see Table 3.12 on page 68) to the MD5 hash function and - * finish the hash. - */ - MD5_write(&md5_ctx, id_string, MAX_KEY_LEN); - MD5_final(md5_buf, &md5_ctx); - /* - * 6. (Revision 3 only) Do the following 50 times; Take the output from - * the previous MD5 hash and pass it as input into a new MD5 hash. - */ - if (revision == 3) - for (i = 0; i < 50; i++) { - /* - * NOTE: We truncate each MD5 hash as in the following step. - * Otherwise Adobe Reader won't decrypt the PDF file. - */ - MD5_init(&md5_ctx); - MD5_write(&md5_ctx, md5_buf, key_size); - MD5_final(md5_buf, &md5_ctx); - } - /* - * 7. Set the encryption key to the first n bytes of the output from - * the final MD5 hash, where n is always 5 for revision 2 but for - * revision 3 depends on the value of the encryption dictionary's - * Length entry. - */ - memcpy(key_data, md5_buf, key_size); -} - -static void compute_user_password (void) -{ - register unsigned char i, j; - /* - * Algorithm 3.4 Computing the encryption dictionary's U (user password) - * value (Revision 2) - * - * 1. Create an encryption key based on the user password string, as - * described in Algorithm 3.2. - * - * 2. Encrypt the 32-byte padding string shown in step 1 of Algorithm - * 3.2, using an RC4 encryption fuction with the encryption key from - * the preceeding step. - * - * 3. Store the result of step 2 as the value of the U entry in the - * encryption dictionary. - */ - /* - * Algorithm 3.5 Computing the encryption dictionary's U (user password) - * value (Revision 3) - * - * 1. Create an encryption key based on the user password string, as - * described in Algorithm 3.2. - * - * 2. Initialize the MD5 hash function and pass the 32-byte padding - * string shown in step 1 of Algorithm 3.2 as input to this function. - * - * 3. Pass the first element of the file's file identifier array (the - * value of the ID entry in the document's trailer dictionary; see - * Table 3.12 on page 68) to the hash function and finish the hash. - * - * 4. Encrypt the 16-byte result of the hash, using an RC4 encryption - * function with the encryption key from step 1. - * - * 5. Do the following 19 times: Take the output from the previous - * invocation of the RC4 function and pass it as input to a new - * invocation of the function; use an encryption key generated by - * taking each byte of the original encryption key (obtained in - * step 1) and performing an XOR (exclusive or) operation between - * that byte and the single-byte value of the iteration counter - * (from 1 to 19). - * - * 6. Append 16 bytes of arbitrary padding to the output from the - * final invocation of the RC4 function and store the 32-byte - * result as the value of the U entry in the encryption dictionary. - */ - compute_encryption_key((unsigned char *)user_passwd); - - switch (revision) { - case 2: - ARC4_set_key(&key, key_size, key_data); - ARC4(&key, MAX_STR_LEN, padding_string, out_buf); - break; - case 3: - MD5_init(&md5_ctx); - MD5_write(&md5_ctx, padding_string, MAX_STR_LEN); - - MD5_write(&md5_ctx, id_string, MAX_KEY_LEN); - MD5_final(md5_buf, &md5_ctx); - - ARC4_set_key(&key, key_size, key_data); - ARC4(&key, MAX_KEY_LEN, md5_buf, out_buf); - - for (i = 1; i <= 19; i++) { - memcpy(in_buf, out_buf, MAX_KEY_LEN); - for (j = 0; j < key_size; j++) - key_buf[j] = key_data[j] ^ i; - ARC4_set_key(&key, key_size, key_buf); - ARC4(&key, MAX_KEY_LEN, in_buf, out_buf); - } - break; - default: - ERROR("Invalid revision number.\n"); - } - - memcpy(upwd_string, out_buf, MAX_STR_LEN); -} - -#ifdef WIN32 -static char *getpass (const char *prompt) -{ - static char pwd_buf[128]; - size_t i; - - fputs(prompt, stderr); - fflush(stderr); - for (i = 0; i < sizeof(pwd_buf)-1; i++) { - pwd_buf[i] = getch(); - if (pwd_buf[i] == '\r') - break; - fputs("*", stderr); - fflush(stderr); - } - pwd_buf[i] = '\0'; - fputs("\n", stderr); - return pwd_buf; -} -#endif - -void pdf_enc_set_passwd (unsigned bits, unsigned perm, const char *owner_pw, const char *user_pw) -{ - char *retry_passwd; - - if (owner_pw) { - strncpy(owner_passwd, owner_pw, MAX_PWD_LEN); - } else - while (1) { - strncpy(owner_passwd, getpass("Owner password: "), MAX_PWD_LEN); - retry_passwd = getpass("Re-enter owner password: "); - if (!strncmp(owner_passwd, retry_passwd, MAX_PWD_LEN)) - break; - fputs("Password is not identical.\nTry again.\n", stderr); - fflush(stderr); - } - - if (user_pw) { - strncpy(user_passwd, user_pw, MAX_PWD_LEN); - } else - while (1) { - strncpy(user_passwd, getpass("User password: "), MAX_PWD_LEN); - retry_passwd = getpass("Re-enter user password: "); - if (!strncmp(user_passwd, retry_passwd, MAX_PWD_LEN)) - break; - fputs("Password is not identical.\nTry again.\n", stderr); - fflush(stderr); - } - - key_size = (unsigned char)(bits / 8); - algorithm = (key_size == 5 ? 1 : 2); - permission = (unsigned long)perm | 0x000000C0; - revision = ((algorithm == 1 && permission < 0x100) ? 2 : 3); - if (revision == 3) - permission |= 0xFFFFF000; - - compute_owner_password(); - compute_user_password(); -} - -void pdf_encrypt_data (unsigned char *data, unsigned long len) -{ - unsigned char *result; - - memcpy(in_buf, key_data, key_size); - in_buf[key_size] = (unsigned char)(current_label) & 0xFF; - in_buf[key_size+1] = (unsigned char)(current_label >> 8) & 0xFF; - in_buf[key_size+2] = (unsigned char)(current_label >> 16) & 0xFF; - in_buf[key_size+3] = (unsigned char)(current_generation) & 0xFF; - in_buf[key_size+4] = (unsigned char)(current_generation >> 8) & 0xFF; - - MD5_init(&md5_ctx); - MD5_write(&md5_ctx, in_buf, key_size+5); - MD5_final(md5_buf, &md5_ctx); - - result = NEW (len, unsigned char); - ARC4_set_key(&key, (key_size > 10 ? MAX_KEY_LEN : key_size+5), md5_buf); - ARC4(&key, len, data, result); - memcpy(data, result, len); - RELEASE (result); -} - -pdf_obj *pdf_encrypt_obj (void) -{ - pdf_obj *doc_encrypt; - -#ifdef DEBUG - fprintf (stderr, "(pdf_encrypt_obj)"); -#endif - - doc_encrypt = pdf_new_dict (); - - /* KEY : Filter - * TYPE : name - * VALUE: (Required) The name of the security handler for this document; - * see below. Default value: Standard, for the built-in security - * handler. - */ - pdf_add_dict (doc_encrypt, - pdf_new_name ("Filter"), - pdf_new_name ("Standard")); - /* KEY : V - * TYPE : number - * VALUE: (Optional but strongly recommended) A code specifying the - * algorithm to be used in encrypting and decrypting the document: - * 0 An algorithm that is undocumented and no longer supported, - * and whose use is strongly discouraged. - * 1 Algorithm 3.1 on page 73, with an encryption key length - * of 40 bits; see below. - * 2 (PDF 1.4) Algorithm 3.1 on page 73, but allowing encryption - * key lengths greater than 40 bits. - * 3 (PDF 1.4) An unpublished algorithm allowing encryption key - * lengths ranging from 40 to 128 bits. (This algorithm is - * unpublished as an export requirement of the U.S. Department - * of Commerce.) - * The default value if this entry is omitted is 0, but a value - * of 1 or greater is strongly recommended. - */ - pdf_add_dict (doc_encrypt, - pdf_new_name ("V"), - pdf_new_number (algorithm)); - /* KEY : Length - * TYPE : integer - * VALUE: (Optional; PDF 1.4; only if V is 2 or 3) The length of the - * encryption key, in bits. The value must be a multiple of 8, - * in the range 40 to 128. Default value: 40. - */ - if (algorithm > 1) - pdf_add_dict (doc_encrypt, - pdf_new_name ("Length"), - pdf_new_number (key_size * 8)); - /* KEY : R - * TYPE : number - * VALUE: (Required) A number specifying which revision of the standard - * security handler should be used to interpret this dictionary. - * The revison number should be 2 if the document is encrypted - * with a V value less than 2; otherwise this value should be 3. - */ - pdf_add_dict (doc_encrypt, - pdf_new_name ("R"), - pdf_new_number (revision)); - /* KEY : O - * TYPE : string - * VALUE: (Required) A 32-byte string, based on both the owner and - * user passwords, that is used in computing the encryption - * key and in determining whether a valid owner password was - * entered. - */ - pdf_add_dict (doc_encrypt, - pdf_new_name ("O"), - pdf_new_string (opwd_string, 32)); - /* KEY : U - * TYPE : string - * VALUE: (Required) A 32-byte string, based on the user password, - * that is used in determining whether to prompt the user - * for a password and, if so, whether a valid user or owner - * password was entered. - */ - pdf_add_dict (doc_encrypt, - pdf_new_name ("U"), - pdf_new_string (upwd_string, 32)); - /* KEY : P - * TYPE : integer - * VALUE: (Required) A set of flags specifying which operations are - * permitted when the document is opened with user access. - */ - pdf_add_dict (doc_encrypt, - pdf_new_name ("P"), - pdf_new_number (permission)); - - return doc_encrypt; -} - -pdf_obj *pdf_enc_id_array (void) -{ - pdf_obj *id = pdf_new_array(); - pdf_add_array(id, pdf_new_string(id_string, MAX_KEY_LEN)); - pdf_add_array(id, pdf_new_string(id_string, MAX_KEY_LEN)); - return id; -} - -void pdf_enc_set_label (unsigned long label) -{ - current_label = label; -} - -void pdf_enc_set_generation (unsigned generation) -{ - current_generation = generation; -} |