diff options
| -rw-r--r-- | source/pdf/pdf-crypt.c | 105 |
1 files changed, 59 insertions, 46 deletions
diff --git a/source/pdf/pdf-crypt.c b/source/pdf/pdf-crypt.c index 1ceaa1be..7150f66e 100644 --- a/source/pdf/pdf-crypt.c +++ b/source/pdf/pdf-crypt.c @@ -640,8 +640,8 @@ pdf_authenticate_user_password(fz_context *ctx, pdf_crypt *crypt, unsigned char } /* - * Authenticating the owner password (PDF 1.7 algorithm 3.7 - * and ExtensionLevel 3 algorithm 3.12) + * Authenticating the owner password (PDF 1.7 algorithm 3.7, + * ExtensionLevel 3 algorithm 3.12, ExtensionLevel 8 algorithm) * Generates the user password from the owner password * and calls pdf_authenticate_user_password. */ @@ -649,63 +649,60 @@ pdf_authenticate_user_password(fz_context *ctx, pdf_crypt *crypt, unsigned char static int pdf_authenticate_owner_password(fz_context *ctx, pdf_crypt *crypt, unsigned char *ownerpass, size_t pwlen) { - unsigned char pwbuf[32]; - unsigned char key[32]; - unsigned char xor[32]; - unsigned char userpass[32]; - int i, n, x; - fz_md5 md5; - fz_arc4 arc4; - - if (crypt->r == 5) - { - /* PDF 1.7 ExtensionLevel 3 algorithm 3.12 */ - pdf_compute_encryption_key_r5(ctx, crypt, ownerpass, pwlen, 1, key); - return !memcmp(key, crypt->o, 32); - } - else if (crypt->r == 6) + if (crypt->r == 2) { - /* PDF 1.7 ExtensionLevel 8 algorithm */ - pdf_compute_encryption_key_r6(ctx, crypt, ownerpass, pwlen, 1, key); - return !memcmp(key, crypt->o, 32); - } + unsigned char pwbuf[32]; + unsigned char key[32]; + unsigned char userpass[32]; + int n; + fz_md5 md5; + fz_arc4 arc4; - n = crypt->length / 8; + n = crypt->length / 8; - /* Step 1 -- steps 1 to 4 of PDF 1.7 algorithm 3.3 */ + if (pwlen > 32) + pwlen = 32; + memcpy(pwbuf, ownerpass, pwlen); + memcpy(pwbuf + pwlen, padding, 32 - pwlen); - /* copy and pad password string */ - if (pwlen > 32) - pwlen = 32; - memcpy(pwbuf, ownerpass, pwlen); - memcpy(pwbuf + pwlen, padding, 32 - pwlen); + fz_md5_init(&md5); + fz_md5_update(&md5, pwbuf, 32); + fz_md5_final(&md5, key); - /* take md5 hash of padded password */ - fz_md5_init(&md5); - fz_md5_update(&md5, pwbuf, 32); - fz_md5_final(&md5, key); + fz_arc4_init(&arc4, key, n); + fz_arc4_encrypt(&arc4, userpass, crypt->o, 32); - /* do some voodoo 50 times (Revision 3 or greater) */ - if (crypt->r >= 3) + return pdf_authenticate_user_password(ctx, crypt, userpass, 32); + } + + if (crypt->r == 3 || crypt->r == 4) { + unsigned char pwbuf[32]; + unsigned char key[32]; + unsigned char xor[32]; + unsigned char userpass[32]; + int i, n, x; + fz_md5 md5; + fz_arc4 arc4; + + n = crypt->length / 8; + + if (pwlen > 32) + pwlen = 32; + memcpy(pwbuf, ownerpass, pwlen); + memcpy(pwbuf + pwlen, padding, 32 - pwlen); + + fz_md5_init(&md5); + fz_md5_update(&md5, pwbuf, 32); + fz_md5_final(&md5, key); + for (i = 0; i < 50; i++) { fz_md5_init(&md5); fz_md5_update(&md5, key, 16); fz_md5_final(&md5, key); } - } - /* Step 2 (Revision 2) */ - if (crypt->r == 2) - { - fz_arc4_init(&arc4, key, n); - fz_arc4_encrypt(&arc4, userpass, crypt->o, 32); - } - - /* Step 2 (Revision 3 or greater) */ - if (crypt->r >= 3) - { memcpy(userpass, crypt->o, 32); for (x = 0; x < 20; x++) { @@ -714,9 +711,25 @@ pdf_authenticate_owner_password(fz_context *ctx, pdf_crypt *crypt, unsigned char fz_arc4_init(&arc4, xor, n); fz_arc4_encrypt(&arc4, userpass, userpass, 32); } + + return pdf_authenticate_user_password(ctx, crypt, userpass, 32); + } + + if (crypt->r == 5) + { + unsigned char key[32]; + pdf_compute_encryption_key_r5(ctx, crypt, ownerpass, pwlen, 1, key); + return !memcmp(key, crypt->o, 32); } - return pdf_authenticate_user_password(ctx, crypt, userpass, 32); + if (crypt->r == 6) + { + unsigned char key[32]; + pdf_compute_encryption_key_r6(ctx, crypt, ownerpass, pwlen, 1, key); + return !memcmp(key, crypt->o, 32); + } + + return 0; } static void pdf_docenc_from_utf8(char *password, const char *utf8, int n) |