lib/smime/cmsattr.c
author J.C. Jones <jjones@mozilla.com>
Fri, 21 Jun 2019 14:39:01 -0700
branchNSS_3_36_BRANCH
changeset 15182 de60f2b7f0c3fac0537346f1077f03d6d849edc5
parent 12781 fb4537ffb64f2a9cb9df8a11b326f308e07c8eba
permissions -rw-r--r--
Added tag NSS_3_36_8_RTM for changeset df8917878ea6

/* 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/. */

/*
 * CMS attributes.
 */

#include "cmslocal.h"

#include "secasn1.h"
#include "secitem.h"
#include "secoid.h"
#include "pk11func.h"
#include "prtime.h"
#include "secerr.h"

/*
 * -------------------------------------------------------------------
 * XXX The following Attribute stuff really belongs elsewhere.
 * The Attribute type is *not* part of CMS but rather X.501.
 * But for now, since CMS is the only customer of attributes,
 * we define them here.  Once there is a use outside of CMS,
 * then change the attribute types and functions from internal
 * to external naming convention, and move them elsewhere!
 */

/*
 * NSS_CMSAttribute_Create - create an attribute
 *
 * if value is NULL, the attribute won't have a value. It can be added later
 * with NSS_CMSAttribute_AddValue.
 */
NSSCMSAttribute *
NSS_CMSAttribute_Create(PLArenaPool *poolp, SECOidTag oidtag, SECItem *value,
                        PRBool encoded)
{
    NSSCMSAttribute *attr;
    SECItem *copiedvalue;
    void *mark;

    PORT_Assert(poolp != NULL);

    mark = PORT_ArenaMark(poolp);

    attr = (NSSCMSAttribute *)PORT_ArenaZAlloc(poolp, sizeof(NSSCMSAttribute));
    if (attr == NULL)
        goto loser;

    attr->typeTag = SECOID_FindOIDByTag(oidtag);
    if (attr->typeTag == NULL)
        goto loser;

    if (SECITEM_CopyItem(poolp, &(attr->type), &(attr->typeTag->oid)) != SECSuccess)
        goto loser;

    if (value != NULL) {
        if ((copiedvalue = SECITEM_ArenaDupItem(poolp, value)) == NULL)
            goto loser;

        if (NSS_CMSArray_Add(poolp, (void ***)&(attr->values), (void *)copiedvalue) != SECSuccess)
            goto loser;
    }

    attr->encoded = encoded;

    PORT_ArenaUnmark(poolp, mark);

    return attr;

loser:
    PORT_Assert(mark != NULL);
    PORT_ArenaRelease(poolp, mark);
    return NULL;
}

/*
 * NSS_CMSAttribute_AddValue - add another value to an attribute
 */
SECStatus
NSS_CMSAttribute_AddValue(PLArenaPool *poolp, NSSCMSAttribute *attr, SECItem *value)
{
    SECItem *copiedvalue;
    void *mark;

    PORT_Assert(poolp != NULL);

    mark = PORT_ArenaMark(poolp);

    if (value == NULL) {
        PORT_SetError(SEC_ERROR_INVALID_ARGS);
        goto loser;
    }

    if ((copiedvalue = SECITEM_ArenaDupItem(poolp, value)) == NULL)
        goto loser;

    if (NSS_CMSArray_Add(poolp, (void ***)&(attr->values), (void *)copiedvalue) != SECSuccess)
        goto loser;

    PORT_ArenaUnmark(poolp, mark);
    return SECSuccess;

loser:
    PORT_Assert(mark != NULL);
    PORT_ArenaRelease(poolp, mark);
    return SECFailure;
}

/*
 * NSS_CMSAttribute_GetType - return the OID tag
 */
SECOidTag
NSS_CMSAttribute_GetType(NSSCMSAttribute *attr)
{
    SECOidData *typetag;

    typetag = SECOID_FindOID(&(attr->type));
    if (typetag == NULL)
        return SEC_OID_UNKNOWN;

    return typetag->offset;
}

/*
 * NSS_CMSAttribute_GetValue - return the first attribute value
 *
 * We do some sanity checking first:
 * - Multiple values are *not* expected.
 * - Empty values are *not* expected.
 */
SECItem *
NSS_CMSAttribute_GetValue(NSSCMSAttribute *attr)
{
    SECItem *value;

    if (attr == NULL)
        return NULL;

    value = attr->values[0];

    if (value == NULL || value->data == NULL || value->len == 0)
        return NULL;

    if (attr->values[1] != NULL)
        return NULL;

    return value;
}

/*
 * NSS_CMSAttribute_CompareValue - compare the attribute's first value against data
 */
PRBool
NSS_CMSAttribute_CompareValue(NSSCMSAttribute *attr, SECItem *av)
{
    SECItem *value;

    if (attr == NULL)
        return PR_FALSE;

    value = NSS_CMSAttribute_GetValue(attr);

    return (value != NULL && value->len == av->len &&
            PORT_Memcmp(value->data, av->data, value->len) == 0);
}

/*
 * templates and functions for separate ASN.1 encoding of attributes
 *
 * used in NSS_CMSAttributeArray_Reorder
 */

/*
 * helper function for dynamic template determination of the attribute value
 */
static const SEC_ASN1Template *
cms_attr_choose_attr_value_template(void *src_or_dest, PRBool encoding)
{
    const SEC_ASN1Template *theTemplate;
    NSSCMSAttribute *attribute;
    SECOidData *oiddata;
    PRBool encoded;

    PORT_Assert(src_or_dest != NULL);
    if (src_or_dest == NULL)
        return NULL;

    attribute = (NSSCMSAttribute *)src_or_dest;

    if (encoding && (!attribute->values || !attribute->values[0] ||
                     attribute->encoded)) {
        /* we're encoding, and the attribute has no value or the attribute
         * value is already encoded. */
        return SEC_ASN1_GET(SEC_AnyTemplate);
    }

    /* get attribute's typeTag */
    oiddata = attribute->typeTag;
    if (oiddata == NULL) {
        oiddata = SECOID_FindOID(&attribute->type);
        attribute->typeTag = oiddata;
    }

    if (oiddata == NULL) {
        /* still no OID tag? OID is unknown then. en/decode value as ANY. */
        encoded = PR_TRUE;
        theTemplate = SEC_ASN1_GET(SEC_AnyTemplate);
    } else {
        switch (oiddata->offset) {
            case SEC_OID_PKCS9_SMIME_CAPABILITIES:
            case SEC_OID_SMIME_ENCRYPTION_KEY_PREFERENCE:
            /* these guys need to stay DER-encoded */
            default:
                /* same goes for OIDs that are not handled here */
                encoded = PR_TRUE;
                theTemplate = SEC_ASN1_GET(SEC_AnyTemplate);
                break;
            /* otherwise choose proper template */
            case SEC_OID_PKCS9_EMAIL_ADDRESS:
            case SEC_OID_RFC1274_MAIL:
            case SEC_OID_PKCS9_UNSTRUCTURED_NAME:
                encoded = PR_FALSE;
                theTemplate = SEC_ASN1_GET(SEC_IA5StringTemplate);
                break;
            case SEC_OID_PKCS9_CONTENT_TYPE:
                encoded = PR_FALSE;
                theTemplate = SEC_ASN1_GET(SEC_ObjectIDTemplate);
                break;
            case SEC_OID_PKCS9_MESSAGE_DIGEST:
                encoded = PR_FALSE;
                theTemplate = SEC_ASN1_GET(SEC_OctetStringTemplate);
                break;
            case SEC_OID_PKCS9_SIGNING_TIME:
                encoded = PR_FALSE;
                theTemplate = SEC_ASN1_GET(CERT_TimeChoiceTemplate);
                break;
                /* XXX Want other types here, too */
        }
    }

    if (encoding) {
        /*
         * If we are encoding and we think we have an already-encoded value,
         * then the code which initialized this attribute should have set
         * the "encoded" property to true (and we would have returned early,
         * up above).  No devastating error, but that code should be fixed.
         * (It could indicate that the resulting encoded bytes are wrong.)
         */
        PORT_Assert(!encoded);
    } else {
        /*
         * We are decoding; record whether the resulting value is
         * still encoded or not.
         */
        attribute->encoded = encoded;
    }
    return theTemplate;
}

static const SEC_ASN1TemplateChooserPtr cms_attr_chooser = cms_attr_choose_attr_value_template;

const SEC_ASN1Template nss_cms_attribute_template[] = {
    { SEC_ASN1_SEQUENCE,
      0, NULL, sizeof(NSSCMSAttribute) },
    { SEC_ASN1_OBJECT_ID,
      offsetof(NSSCMSAttribute, type) },
    { SEC_ASN1_DYNAMIC | SEC_ASN1_SET_OF,
      offsetof(NSSCMSAttribute, values),
      &cms_attr_chooser },
    { 0 }
};

const SEC_ASN1Template nss_cms_set_of_attribute_template[] = {
    { SEC_ASN1_SET_OF, 0, nss_cms_attribute_template },
};

/* =============================================================================
 * Attribute Array methods
 */

/*
 * NSS_CMSAttributeArray_Encode - encode an Attribute array as SET OF Attributes
 *
 * If you are wondering why this routine does not reorder the attributes
 * first, and might be tempted to make it do so, see the comment by the
 * call to ReorderAttributes in cmsencode.c.  (Or, see who else calls this
 * and think long and hard about the implications of making it always
 * do the reordering.)
 */
SECItem *
NSS_CMSAttributeArray_Encode(PLArenaPool *poolp, NSSCMSAttribute ***attrs, SECItem *dest)
{
    return SEC_ASN1EncodeItem(poolp, dest, (void *)attrs, nss_cms_set_of_attribute_template);
}

/*
 * NSS_CMSAttributeArray_Reorder - sort attribute array by attribute's DER encoding
 *
 * make sure that the order of the attributes guarantees valid DER (which must be
 * in lexigraphically ascending order for a SET OF); if reordering is necessary it
 * will be done in place (in attrs).
 */
SECStatus
NSS_CMSAttributeArray_Reorder(NSSCMSAttribute **attrs)
{
    return NSS_CMSArray_SortByDER((void **)attrs, nss_cms_attribute_template, NULL);
}

/*
 * NSS_CMSAttributeArray_FindAttrByOidTag - look through a set of attributes and
 * find one that matches the specified object ID.
 *
 * If "only" is true, then make sure that there is not more than one attribute
 * of the same type.  Otherwise, just return the first one found. (XXX Does
 * anybody really want that first-found behavior?  It was like that when I found it...)
 */
NSSCMSAttribute *
NSS_CMSAttributeArray_FindAttrByOidTag(NSSCMSAttribute **attrs, SECOidTag oidtag, PRBool only)
{
    SECOidData *oid;
    NSSCMSAttribute *attr1, *attr2;

    if (attrs == NULL)
        return NULL;

    oid = SECOID_FindOIDByTag(oidtag);
    if (oid == NULL)
        return NULL;

    while ((attr1 = *attrs++) != NULL) {
        if (attr1->type.len == oid->oid.len &&
            PORT_Memcmp(attr1->type.data, oid->oid.data, oid->oid.len) == 0)
            break;
    }

    if (attr1 == NULL)
        return NULL;

    if (!only)
        return attr1;

    while ((attr2 = *attrs++) != NULL) {
        if (attr2->type.len == oid->oid.len &&
            PORT_Memcmp(attr2->type.data, oid->oid.data, oid->oid.len) == 0)
            break;
    }

    if (attr2 != NULL)
        return NULL;

    return attr1;
}

/*
 * NSS_CMSAttributeArray_AddAttr - add an attribute to an
 * array of attributes.
 */
SECStatus
NSS_CMSAttributeArray_AddAttr(PLArenaPool *poolp, NSSCMSAttribute ***attrs,
                              NSSCMSAttribute *attr)
{
    NSSCMSAttribute *oattr;
    void *mark;
    SECOidTag type;

    mark = PORT_ArenaMark(poolp);

    /* find oidtag of attr */
    type = NSS_CMSAttribute_GetType(attr);

    /* see if we have one already */
    oattr = NSS_CMSAttributeArray_FindAttrByOidTag(*attrs, type, PR_FALSE);
    PORT_Assert(oattr == NULL);
    if (oattr != NULL)
        goto loser; /* XXX or would it be better to replace it? */

    /* no, shove it in */
    if (NSS_CMSArray_Add(poolp, (void ***)attrs, (void *)attr) != SECSuccess)
        goto loser;

    PORT_ArenaUnmark(poolp, mark);
    return SECSuccess;

loser:
    PORT_ArenaRelease(poolp, mark);
    return SECFailure;
}

/*
 * NSS_CMSAttributeArray_SetAttr - set an attribute's value in a set of attributes
 */
SECStatus
NSS_CMSAttributeArray_SetAttr(PLArenaPool *poolp, NSSCMSAttribute ***attrs,
                              SECOidTag type, SECItem *value, PRBool encoded)
{
    NSSCMSAttribute *attr;
    void *mark;

    mark = PORT_ArenaMark(poolp);

    /* see if we have one already */
    attr = NSS_CMSAttributeArray_FindAttrByOidTag(*attrs, type, PR_FALSE);
    if (attr == NULL) {
        /* not found? create one! */
        attr = NSS_CMSAttribute_Create(poolp, type, value, encoded);
        if (attr == NULL)
            goto loser;
        /* and add it to the list */
        if (NSS_CMSArray_Add(poolp, (void ***)attrs, (void *)attr) != SECSuccess)
            goto loser;
    } else {
        /* found, shove it in */
        /* XXX we need a decent memory model @#$#$!#!!! */
        attr->values[0] = value;
        attr->encoded = encoded;
    }

    PORT_ArenaUnmark(poolp, mark);
    return SECSuccess;

loser:
    PORT_ArenaRelease(poolp, mark);
    return SECFailure;
}