The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #include "pkcs12.h"

 #include "plarena.h"

 #include "secpkcs7.h"

 #include "p12local.h"

 #include "secoid.h"

 #include "secitem.h"

 #include "secport.h"

 #include "secasn1.h"

 #include "secder.h"

 #include "secerr.h"

 #include "cert.h"

 #include "certdb.h"

 #include "p12plcy.h"

 #include "p12.h" 

 #include "secpkcs5.h" 

 /* PFX extraction and validation routines */

 /* decode the DER encoded PFX item.  if unable to decode, check to see if it

  * is an older PFX item.  If that fails, assume the file was not a valid

  * pfx file.

  * the returned pfx structure should be destroyed using SEC_PKCS12DestroyPFX

  */

 static SEC_PKCS12PFXItem *

 sec_pkcs12_decode_pfx(SECItem *der_pfx)

 {

     SEC_PKCS12PFXItem *pfx;

     SECStatus rv;

     if(der_pfx == NULL) {

 	return NULL;

     }

     /* allocate the space for a new PFX item */

     pfx = sec_pkcs12_new_pfx();

     if(pfx == NULL) {

 	return NULL;

     }

     rv = SEC_ASN1DecodeItem(pfx->poolp, pfx, SEC_PKCS12PFXItemTemplate, 

     			    der_pfx);

     /* if a failure occurred, check for older version...

      * we also get rid of the old pfx structure, because we don't

      * know where it failed and what data in may contain

      */

     if(rv != SECSuccess) {

 	SEC_PKCS12DestroyPFX(pfx);

 	pfx = sec_pkcs12_new_pfx();

 	if(pfx == NULL) {

 	    return NULL;

 	}

 	rv = SEC_ASN1DecodeItem(pfx->poolp, pfx, SEC_PKCS12PFXItemTemplate_OLD, 

 				der_pfx);

 	if(rv != SECSuccess) {

 	    PORT_SetError(SEC_ERROR_PKCS12_DECODING_PFX);

 	    PORT_FreeArena(pfx->poolp, PR_TRUE);

 	    return NULL;

 	}

 	pfx->old = PR_TRUE;

 	SGN_CopyDigestInfo(pfx->poolp, &pfx->macData.safeMac, &pfx->old_safeMac);

 	SECITEM_CopyItem(pfx->poolp, &pfx->macData.macSalt, &pfx->old_macSalt);

     } else {

 	pfx->old = PR_FALSE;

     }

     /* convert bit string from bits to bytes */

     pfx->macData.macSalt.len /= 8;

     return pfx;

 }

 /* validate the integrity MAC used in the PFX.  The MAC is generated

  * per the PKCS 12 document.  If the MAC is incorrect, it is most likely

  * due to an invalid password.

  * pwitem is the integrity password

  * pfx is the decoded pfx item

  */

 static PRBool 

 sec_pkcs12_check_pfx_mac(SEC_PKCS12PFXItem *pfx,

 			 SECItem *pwitem)

 {

     SECItem *key = NULL, *mac = NULL, *data = NULL;

     SECItem *vpwd = NULL;

     SECOidTag algorithm;

     PRBool ret = PR_FALSE;

     if(pfx == NULL) {

 	return PR_FALSE;

     }

     algorithm = SECOID_GetAlgorithmTag(&pfx->macData.safeMac.digestAlgorithm);

     switch(algorithm) {

 	/* only SHA1 hashing supported as a MACing algorithm */

 	case SEC_OID_SHA1:

 	    if(pfx->old == PR_FALSE) {

 		pfx->swapUnicode = PR_FALSE;

 	    }

 recheckUnicodePassword:

 	    vpwd = sec_pkcs12_create_virtual_password(pwitem, 

 	    					&pfx->macData.macSalt, 

 						pfx->swapUnicode);

 	    if(vpwd == NULL) {

 		return PR_FALSE;

 	    }

 	    key = sec_pkcs12_generate_key_from_password(algorithm,

 						&pfx->macData.macSalt, 

 						(pfx->old ? pwitem : vpwd));

 	    /* free vpwd only for newer PFX */

 	    if(vpwd) {

 		SECITEM_ZfreeItem(vpwd, PR_TRUE);

 	    }

 	    if(key == NULL) {

 		return PR_FALSE;

 	    }

 	    data = SEC_PKCS7GetContent(&pfx->authSafe);

 	    if(data == NULL) {

 		break;

 	    }

 	    /* check MAC */

 	    mac = sec_pkcs12_generate_mac(key, data, pfx->old);

 	    ret = PR_TRUE;

 	    if(mac) {

 		SECItem *safeMac = &pfx->macData.safeMac.digest;

 		if(SECITEM_CompareItem(mac, safeMac) != SECEqual) {

 		    /* if we encounter an invalid mac, lets invert the

 		     * password in case of unicode changes 

 		     */

 		    if(((!pfx->old) && pfx->swapUnicode) || (pfx->old)){

 			PORT_SetError(SEC_ERROR_PKCS12_INVALID_MAC);

 			ret = PR_FALSE;

 		    } else {

 			SECITEM_ZfreeItem(mac, PR_TRUE);

 			pfx->swapUnicode = PR_TRUE;

 			goto recheckUnicodePassword;

 		    }

 		} 

 		SECITEM_ZfreeItem(mac, PR_TRUE);

 	    } else {

 		ret = PR_FALSE;

 	    }

 	    break;

 	default:

 	    PORT_SetError(SEC_ERROR_PKCS12_UNSUPPORTED_MAC_ALGORITHM);

 	    ret = PR_FALSE;

 	    break;

     }

     /* let success fall through */

     if(key != NULL)

 	SECITEM_ZfreeItem(key, PR_TRUE);

     return ret;

 }

 /* check the validity of the pfx structure.  we currently only support

  * password integrity mode, so we check the MAC.

  */

 static PRBool 

 sec_pkcs12_validate_pfx(SEC_PKCS12PFXItem *pfx, 

 			SECItem *pwitem)

 {

     SECOidTag contentType;

     contentType = SEC_PKCS7ContentType(&pfx->authSafe);

     switch(contentType)

     {

 	case SEC_OID_PKCS7_DATA:

 	    return sec_pkcs12_check_pfx_mac(pfx, pwitem);

 	    break;

 	case SEC_OID_PKCS7_SIGNED_DATA:

 	default:

 	    PORT_SetError(SEC_ERROR_PKCS12_UNSUPPORTED_TRANSPORT_MODE);

 	    break;

     }

     return PR_FALSE;

 }

 /* decode and return the valid PFX.  if the PFX item is not valid,

  * NULL is returned.

  */

 static SEC_PKCS12PFXItem *

 sec_pkcs12_get_pfx(SECItem *pfx_data, 

 		   SECItem *pwitem)

 {

     SEC_PKCS12PFXItem *pfx;

     PRBool valid_pfx;

     if((pfx_data == NULL) || (pwitem == NULL)) {

 	return NULL;

     }

     pfx = sec_pkcs12_decode_pfx(pfx_data);

     if(pfx == NULL) {

 	return NULL;

     }

     valid_pfx = sec_pkcs12_validate_pfx(pfx, pwitem);

     if(valid_pfx != PR_TRUE) {

 	SEC_PKCS12DestroyPFX(pfx);

 	pfx = NULL;

     }

     return pfx;

 }

 /* authenticated safe decoding, validation, and access routines

  */

 /* convert dogbert beta 3 authenticated safe structure to a post

  * beta three structure, so that we don't have to change more routines.

  */

 static SECStatus

 sec_pkcs12_convert_old_auth_safe(SEC_PKCS12AuthenticatedSafe *asafe)

 {

     SEC_PKCS12Baggage *baggage;

     SEC_PKCS12BaggageItem *bag;

     SECStatus rv = SECSuccess;

     if(asafe->old_baggage.espvks == NULL) {

 	/* XXX should the ASN1 engine produce a single NULL element list

 	 * rather than setting the pointer to NULL?  

 	 * There is no need to return an error -- assume that the list

 	 * was empty.

 	 */

 	return SECSuccess;

     }

     baggage = sec_pkcs12_create_baggage(asafe->poolp);

     if(!baggage) {

 	return SECFailure;

     }

     bag = sec_pkcs12_create_external_bag(baggage);

     if(!bag) {

 	return SECFailure;

     }

     PORT_Memcpy(&asafe->baggage, baggage, sizeof(SEC_PKCS12Baggage));

     /* if there are shrouded keys, append them to the bag */

     rv = SECSuccess;

     if(asafe->old_baggage.espvks[0] != NULL) {

 	int nEspvk = 0;

 	rv = SECSuccess;

 	while((asafe->old_baggage.espvks[nEspvk] != NULL) && 

 		(rv == SECSuccess)) {

 	    rv = sec_pkcs12_append_shrouded_key(bag, 

 	    				asafe->old_baggage.espvks[nEspvk]);

 	    nEspvk++;

 	}

     }

     return rv;

 }    

 /* decodes the authenticated safe item.  a return of NULL indicates

  * an error.  however, the error will have occurred either in memory

  * allocation or in decoding the authenticated safe.

  *

  * if an old PFX item has been found, we want to convert the

  * old authenticated safe to the new one.

  */

 static SEC_PKCS12AuthenticatedSafe *

 sec_pkcs12_decode_authenticated_safe(SEC_PKCS12PFXItem *pfx) 

 {

     SECItem *der_asafe = NULL;

     SEC_PKCS12AuthenticatedSafe *asafe = NULL;

     SECStatus rv;

     if(pfx == NULL) {

 	return NULL;

     }

     der_asafe = SEC_PKCS7GetContent(&pfx->authSafe);

     if(der_asafe == NULL) {

 	/* XXX set error ? */

 	goto loser;

     }

     asafe = sec_pkcs12_new_asafe(pfx->poolp);

     if(asafe == NULL) {

 	goto loser;

     }

     if(pfx->old == PR_FALSE) {

 	rv = SEC_ASN1DecodeItem(pfx->poolp, asafe, 

 			 	SEC_PKCS12AuthenticatedSafeTemplate, 

 			 	der_asafe);

 	asafe->old = PR_FALSE;

 	asafe->swapUnicode = pfx->swapUnicode;

     } else {

 	/* handle beta exported files */

 	rv = SEC_ASN1DecodeItem(pfx->poolp, asafe, 

 				SEC_PKCS12AuthenticatedSafeTemplate_OLD,

 				der_asafe);

 	asafe->safe = &(asafe->old_safe);

 	rv = sec_pkcs12_convert_old_auth_safe(asafe);

 	asafe->old = PR_TRUE;

     }

     if(rv != SECSuccess) {

 	goto loser;

     }

     asafe->poolp = pfx->poolp;

     return asafe;

 loser:

     return NULL;

 }

 /* validates the safe within the authenticated safe item.  

  * in order to be valid:

  *  1.  the privacy salt must be present

  *  2.  the encryption algorithm must be supported (including

  *	export policy)

  * PR_FALSE indicates an error, PR_TRUE indicates a valid safe

  */

 static PRBool 

 sec_pkcs12_validate_encrypted_safe(SEC_PKCS12AuthenticatedSafe *asafe)

 {

     PRBool valid = PR_FALSE;

     SECAlgorithmID *algid;

     if(asafe == NULL) {

 	return PR_FALSE;

     }

     /* if mode is password privacy, then privacySalt is assumed

      * to be non-zero.

      */

     if(asafe->privacySalt.len != 0) {

 	valid = PR_TRUE;

 	asafe->privacySalt.len /= 8;

     } else {

 	PORT_SetError(SEC_ERROR_PKCS12_CORRUPT_PFX_STRUCTURE);

 	return PR_FALSE;

     }

     /* until spec changes, content will have between 2 and 8 bytes depending

      * upon the algorithm used if certs are unencrypted...

      * also want to support case where content is empty -- which we produce 

      */ 

     if(SEC_PKCS7IsContentEmpty(asafe->safe, 8) == PR_TRUE) {

 	asafe->emptySafe = PR_TRUE;

 	return PR_TRUE;

     }

     asafe->emptySafe = PR_FALSE;

     /* make sure that a pbe algorithm is being used */

     algid = SEC_PKCS7GetEncryptionAlgorithm(asafe->safe);

     if(algid != NULL) {

 	if(SEC_PKCS5IsAlgorithmPBEAlg(algid)) {

 	    valid = SEC_PKCS12DecryptionAllowed(algid);

 	    if(valid == PR_FALSE) {

 		PORT_SetError(SEC_ERROR_BAD_EXPORT_ALGORITHM);

 	    }

 	} else {

 	    PORT_SetError(SEC_ERROR_PKCS12_UNSUPPORTED_PBE_ALGORITHM);

 	    valid = PR_FALSE;

 	}

     } else {

 	valid = PR_FALSE;

 	PORT_SetError(SEC_ERROR_PKCS12_UNSUPPORTED_PBE_ALGORITHM);

     }

     return valid;

 }

 /* validates authenticates safe:

  *  1.  checks that the version is supported

  *  2.  checks that only password privacy mode is used (currently)

  *  3.  further, makes sure safe has appropriate policies per above function

  * PR_FALSE indicates failure.

  */

 static PRBool 

 sec_pkcs12_validate_auth_safe(SEC_PKCS12AuthenticatedSafe *asafe)

 {

     PRBool valid = PR_TRUE;

     SECOidTag safe_type;

     int version;

     if(asafe == NULL) {

 	return PR_FALSE;

     }

     /* check version, since it is default it may not be present.

      * therefore, assume ok

      */

     if((asafe->version.len > 0) && (asafe->old == PR_FALSE)) {

 	version = DER_GetInteger(&asafe->version);

 	if(version > SEC_PKCS12_PFX_VERSION) {

 	    PORT_SetError(SEC_ERROR_PKCS12_UNSUPPORTED_VERSION);

 	    return PR_FALSE;

 	}

     }

     /* validate password mode is being used */

     safe_type = SEC_PKCS7ContentType(asafe->safe);

     switch(safe_type)

     {

 	case SEC_OID_PKCS7_ENCRYPTED_DATA:

 	    valid = sec_pkcs12_validate_encrypted_safe(asafe);

 	    break;

 	case SEC_OID_PKCS7_ENVELOPED_DATA:

 	default:

 	    PORT_SetError(SEC_ERROR_PKCS12_UNSUPPORTED_TRANSPORT_MODE);

 	    valid = PR_FALSE;

 	    break;

     }

     return valid;

 }

 /* retrieves the authenticated safe item from the PFX item

  *  before returning the authenticated safe, the validity of the

  *  authenticated safe is checked and if valid, returned.

  * a return of NULL indicates that an error occurred.

  */

 static SEC_PKCS12AuthenticatedSafe *

 sec_pkcs12_get_auth_safe(SEC_PKCS12PFXItem *pfx)

 {

     SEC_PKCS12AuthenticatedSafe *asafe;

     PRBool valid_safe;

     if(pfx == NULL) {

 	return NULL;

     }

     asafe = sec_pkcs12_decode_authenticated_safe(pfx);

     if(asafe == NULL) {

 	return NULL;

     }

     valid_safe = sec_pkcs12_validate_auth_safe(asafe);

     if(valid_safe != PR_TRUE) {

 	asafe = NULL;

     } else if(asafe) {

 	asafe->baggage.poolp = asafe->poolp;

     }

     return asafe;

 }

 /* decrypts the authenticated safe.

  * a return of anything but SECSuccess indicates an error.  the

  * password is not known to be valid until the call to the 

  * function sec_pkcs12_get_safe_contents.  If decoding the safe

  * fails, it is assumed the password was incorrect and the error

  * is set then.  any failure here is assumed to be due to 

  * internal problems in SEC_PKCS7DecryptContents or below.

  */

 static SECStatus

 sec_pkcs12_decrypt_auth_safe(SEC_PKCS12AuthenticatedSafe *asafe, 

 			     SECItem *pwitem,

 			     void *wincx)

 {

     SECStatus rv = SECFailure;

     SECItem *vpwd = NULL;

     if((asafe == NULL) || (pwitem == NULL)) {

 	return SECFailure;

     }

     if(asafe->old == PR_FALSE) {

 	vpwd = sec_pkcs12_create_virtual_password(pwitem, &asafe->privacySalt,

 						 asafe->swapUnicode);

 	if(vpwd == NULL) {

 	    return SECFailure;

 	}

     }

     rv = SEC_PKCS7DecryptContents(asafe->poolp, asafe->safe, 

     				  (asafe->old ? pwitem : vpwd), wincx);

     if(asafe->old == PR_FALSE) {

 	SECITEM_ZfreeItem(vpwd, PR_TRUE);

     }

     return rv;

 }

 /* extract the safe from the authenticated safe.

  *  if we are unable to decode the safe, then it is likely that the 

  *  safe has not been decrypted or the password used to decrypt

  *  the safe was invalid.  we assume that the password was invalid and

  *  set an error accordingly.

  * a return of NULL indicates that an error occurred.

  */

 static SEC_PKCS12SafeContents *

 sec_pkcs12_get_safe_contents(SEC_PKCS12AuthenticatedSafe *asafe)

 {

     SECItem *src = NULL;

     SEC_PKCS12SafeContents *safe = NULL;

     SECStatus rv = SECFailure;

     if(asafe == NULL) {

 	return NULL;

     }

     safe = (SEC_PKCS12SafeContents *)PORT_ArenaZAlloc(asafe->poolp, 

 	    					sizeof(SEC_PKCS12SafeContents));

     if(safe == NULL) {

 	return NULL;

     }

     safe->poolp = asafe->poolp;

     safe->old = asafe->old;

     safe->swapUnicode = asafe->swapUnicode;

     src = SEC_PKCS7GetContent(asafe->safe);

     if(src != NULL) {

 	const SEC_ASN1Template *theTemplate;

 	if(asafe->old != PR_TRUE) {

 	    theTemplate = SEC_PKCS12SafeContentsTemplate;

 	} else {

 	    theTemplate = SEC_PKCS12SafeContentsTemplate_OLD;

 	}

 	rv = SEC_ASN1DecodeItem(asafe->poolp, safe, theTemplate, src);

 	/* if we could not decode the item, password was probably invalid */

 	if(rv != SECSuccess) {

 	    safe = NULL;

 	    PORT_SetError(SEC_ERROR_PKCS12_PRIVACY_PASSWORD_INCORRECT);

 	}

     } else {

 	PORT_SetError(SEC_ERROR_PKCS12_CORRUPT_PFX_STRUCTURE);

 	rv = SECFailure;

     }

     return safe;

 }

 /* import PFX item 

  * der_pfx is the der encoded pfx structure

  * pbef and pbearg are the integrity/encryption password call back

  * ncCall is the nickname collision calllback

  * slot is the destination token

  * wincx window handler

  *

  * on error, error code set and SECFailure returned 

  */

 SECStatus

 SEC_PKCS12PutPFX(SECItem *der_pfx, SECItem *pwitem,

 		 SEC_PKCS12NicknameCollisionCallback ncCall,

 		 PK11SlotInfo *slot,

 		 void *wincx)

 {

     SEC_PKCS12PFXItem *pfx;

     SEC_PKCS12AuthenticatedSafe *asafe;

     SEC_PKCS12SafeContents *safe_contents = NULL;

     SECStatus rv;

     if(!der_pfx || !pwitem || !slot) {

 	return SECFailure;

     }

     /* decode and validate each section */

     rv = SECFailure;

     pfx = sec_pkcs12_get_pfx(der_pfx, pwitem);

     if(pfx != NULL) {

 	asafe = sec_pkcs12_get_auth_safe(pfx);

 	if(asafe != NULL) {

 	    /* decrypt safe -- only if not empty */

 	    if(asafe->emptySafe != PR_TRUE) {

 		rv = sec_pkcs12_decrypt_auth_safe(asafe, pwitem, wincx);

 		if(rv == SECSuccess) {

 		    safe_contents = sec_pkcs12_get_safe_contents(asafe);

 		    if(safe_contents == NULL) {

 			rv = SECFailure;

 		    }

 		}

 	    } else {

 		safe_contents = sec_pkcs12_create_safe_contents(asafe->poolp);

 		if(safe_contents == NULL) {

 		    rv = SECFailure;

 		} else {

                     safe_contents->swapUnicode = pfx->swapUnicode;

 		    rv = SECSuccess;

 		}

 	    }

 	    /* get safe contents and begin import */

 	    if(rv == SECSuccess) {

 		SEC_PKCS12DecoderContext *p12dcx;

 		p12dcx = sec_PKCS12ConvertOldSafeToNew(pfx->poolp, slot,

 					pfx->swapUnicode,

 					pwitem, wincx, safe_contents,

 					&asafe->baggage);

 		if(!p12dcx) {

 		    rv = SECFailure;

 		    goto loser;

 		}

 		if(SEC_PKCS12DecoderValidateBags(p12dcx, ncCall) 

 				!= SECSuccess) {

 		    rv = SECFailure;

 		    goto loser;

 		}

 		rv = SEC_PKCS12DecoderImportBags(p12dcx);

 	    }

 	}

     }

 loser:

     if(pfx) {

 	SEC_PKCS12DestroyPFX(pfx);

     }

     return rv;

 }

 PRBool 

 SEC_PKCS12ValidData(char *buf, int bufLen, long int totalLength)

 {

     int lengthLength;

     PRBool valid = PR_FALSE;

     if(buf == NULL) {

 	return PR_FALSE;

     }

     /* check for constructed sequence identifier tag */

     if(*buf == (SEC_ASN1_CONSTRUCTED | SEC_ASN1_SEQUENCE)) {

 	totalLength--;   /* header byte taken care of */

 	buf++;

 	lengthLength = (long int)SEC_ASN1LengthLength(totalLength - 1);

 	if(totalLength > 0x7f) {

 	    lengthLength--;

 	    *buf &= 0x7f;  /* remove bit 8 indicator */

 	    if((*buf - (char)lengthLength) == 0) {

 		valid = PR_TRUE;

 	    }

 	} else {

 	    lengthLength--;

 	    if((*buf - (char)lengthLength) == 0) {

 		valid = PR_TRUE;

 	    }

 	}

     }

     return valid;

 }