| /* |
| * Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the Apache License 2.0 (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| #include <stddef.h> |
| #include <string.h> |
| #include "internal/cryptlib.h" |
| #include <openssl/asn1.h> |
| #include <openssl/asn1t.h> |
| #include <openssl/objects.h> |
| #include "crypto/asn1.h" |
| #include "asn1_local.h" |
| |
| static int asn1_i2d_ex_primitive(const ASN1_VALUE **pval, unsigned char **out, |
| const ASN1_ITEM *it, int tag, int aclass); |
| static int asn1_set_seq_out(STACK_OF(const_ASN1_VALUE) *sk, |
| unsigned char **out, |
| int skcontlen, const ASN1_ITEM *item, |
| int do_sort, int iclass); |
| static int asn1_template_ex_i2d(const ASN1_VALUE **pval, unsigned char **out, |
| const ASN1_TEMPLATE *tt, int tag, int aclass); |
| static int asn1_item_flags_i2d(const ASN1_VALUE *val, unsigned char **out, |
| const ASN1_ITEM *it, int flags); |
| static int asn1_ex_i2c(const ASN1_VALUE **pval, unsigned char *cout, int *putype, |
| const ASN1_ITEM *it); |
| |
| /* |
| * Top level i2d equivalents: the 'ndef' variant instructs the encoder to use |
| * indefinite length constructed encoding, where appropriate |
| */ |
| |
| int ASN1_item_ndef_i2d(const ASN1_VALUE *val, unsigned char **out, |
| const ASN1_ITEM *it) |
| { |
| return asn1_item_flags_i2d(val, out, it, ASN1_TFLG_NDEF); |
| } |
| |
| int ASN1_item_i2d(const ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it) |
| { |
| return asn1_item_flags_i2d(val, out, it, 0); |
| } |
| |
| /* |
| * Encode an ASN1 item, this is use by the standard 'i2d' function. 'out' |
| * points to a buffer to output the data to. The new i2d has one additional |
| * feature. If the output buffer is NULL (i.e. *out == NULL) then a buffer is |
| * allocated and populated with the encoding. |
| */ |
| |
| static int asn1_item_flags_i2d(const ASN1_VALUE *val, unsigned char **out, |
| const ASN1_ITEM *it, int flags) |
| { |
| if (out != NULL && *out == NULL) { |
| unsigned char *p, *buf; |
| int len; |
| |
| len = ASN1_item_ex_i2d(&val, NULL, it, -1, flags); |
| if (len <= 0) |
| return len; |
| if ((buf = OPENSSL_malloc(len)) == NULL) { |
| ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE); |
| return -1; |
| } |
| p = buf; |
| ASN1_item_ex_i2d(&val, &p, it, -1, flags); |
| *out = buf; |
| return len; |
| } |
| |
| return ASN1_item_ex_i2d(&val, out, it, -1, flags); |
| } |
| |
| /* |
| * Encode an item, taking care of IMPLICIT tagging (if any). This function |
| * performs the normal item handling: it can be used in external types. |
| */ |
| |
| int ASN1_item_ex_i2d(const ASN1_VALUE **pval, unsigned char **out, |
| const ASN1_ITEM *it, int tag, int aclass) |
| { |
| const ASN1_TEMPLATE *tt = NULL; |
| int i, seqcontlen, seqlen, ndef = 1; |
| const ASN1_EXTERN_FUNCS *ef; |
| const ASN1_AUX *aux = it->funcs; |
| ASN1_aux_const_cb *asn1_cb = NULL; |
| |
| if ((it->itype != ASN1_ITYPE_PRIMITIVE) && *pval == NULL) |
| return 0; |
| |
| if (aux != NULL) { |
| asn1_cb = ((aux->flags & ASN1_AFLG_CONST_CB) != 0) ? aux->asn1_const_cb |
| : (ASN1_aux_const_cb *)aux->asn1_cb; /* backward compatibility */ |
| } |
| |
| switch (it->itype) { |
| |
| case ASN1_ITYPE_PRIMITIVE: |
| if (it->templates) |
| return asn1_template_ex_i2d(pval, out, it->templates, |
| tag, aclass); |
| return asn1_i2d_ex_primitive(pval, out, it, tag, aclass); |
| |
| case ASN1_ITYPE_MSTRING: |
| /* |
| * It never makes sense for multi-strings to have implicit tagging, so |
| * if tag != -1, then this looks like an error in the template. |
| */ |
| if (tag != -1) { |
| ERR_raise(ERR_LIB_ASN1, ASN1_R_BAD_TEMPLATE); |
| return -1; |
| } |
| return asn1_i2d_ex_primitive(pval, out, it, -1, aclass); |
| |
| case ASN1_ITYPE_CHOICE: |
| /* |
| * It never makes sense for CHOICE types to have implicit tagging, so |
| * if tag != -1, then this looks like an error in the template. |
| */ |
| if (tag != -1) { |
| ERR_raise(ERR_LIB_ASN1, ASN1_R_BAD_TEMPLATE); |
| return -1; |
| } |
| if (asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it, NULL)) |
| return 0; |
| i = ossl_asn1_get_choice_selector_const(pval, it); |
| if ((i >= 0) && (i < it->tcount)) { |
| const ASN1_VALUE **pchval; |
| const ASN1_TEMPLATE *chtt; |
| chtt = it->templates + i; |
| pchval = ossl_asn1_get_const_field_ptr(pval, chtt); |
| return asn1_template_ex_i2d(pchval, out, chtt, -1, aclass); |
| } |
| /* Fixme: error condition if selector out of range */ |
| if (asn1_cb && !asn1_cb(ASN1_OP_I2D_POST, pval, it, NULL)) |
| return 0; |
| break; |
| |
| case ASN1_ITYPE_EXTERN: |
| /* If new style i2d it does all the work */ |
| ef = it->funcs; |
| return ef->asn1_ex_i2d(pval, out, it, tag, aclass); |
| |
| case ASN1_ITYPE_NDEF_SEQUENCE: |
| /* Use indefinite length constructed if requested */ |
| if (aclass & ASN1_TFLG_NDEF) |
| ndef = 2; |
| /* fall through */ |
| |
| case ASN1_ITYPE_SEQUENCE: |
| i = ossl_asn1_enc_restore(&seqcontlen, out, pval, it); |
| /* An error occurred */ |
| if (i < 0) |
| return 0; |
| /* We have a valid cached encoding... */ |
| if (i > 0) |
| return seqcontlen; |
| /* Otherwise carry on */ |
| seqcontlen = 0; |
| /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */ |
| if (tag == -1) { |
| tag = V_ASN1_SEQUENCE; |
| /* Retain any other flags in aclass */ |
| aclass = (aclass & ~ASN1_TFLG_TAG_CLASS) |
| | V_ASN1_UNIVERSAL; |
| } |
| if (asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it, NULL)) |
| return 0; |
| /* First work out sequence content length */ |
| for (i = 0, tt = it->templates; i < it->tcount; tt++, i++) { |
| const ASN1_TEMPLATE *seqtt; |
| const ASN1_VALUE **pseqval; |
| int tmplen; |
| seqtt = ossl_asn1_do_adb(*pval, tt, 1); |
| if (!seqtt) |
| return 0; |
| pseqval = ossl_asn1_get_const_field_ptr(pval, seqtt); |
| tmplen = asn1_template_ex_i2d(pseqval, NULL, seqtt, -1, aclass); |
| if (tmplen == -1 || (tmplen > INT_MAX - seqcontlen)) |
| return -1; |
| seqcontlen += tmplen; |
| } |
| |
| seqlen = ASN1_object_size(ndef, seqcontlen, tag); |
| if (!out || seqlen == -1) |
| return seqlen; |
| /* Output SEQUENCE header */ |
| ASN1_put_object(out, ndef, seqcontlen, tag, aclass); |
| for (i = 0, tt = it->templates; i < it->tcount; tt++, i++) { |
| const ASN1_TEMPLATE *seqtt; |
| const ASN1_VALUE **pseqval; |
| seqtt = ossl_asn1_do_adb(*pval, tt, 1); |
| if (!seqtt) |
| return 0; |
| pseqval = ossl_asn1_get_const_field_ptr(pval, seqtt); |
| /* FIXME: check for errors in enhanced version */ |
| asn1_template_ex_i2d(pseqval, out, seqtt, -1, aclass); |
| } |
| if (ndef == 2) |
| ASN1_put_eoc(out); |
| if (asn1_cb && !asn1_cb(ASN1_OP_I2D_POST, pval, it, NULL)) |
| return 0; |
| return seqlen; |
| |
| default: |
| return 0; |
| |
| } |
| return 0; |
| } |
| |
| static int asn1_template_ex_i2d(const ASN1_VALUE **pval, unsigned char **out, |
| const ASN1_TEMPLATE *tt, int tag, int iclass) |
| { |
| const int flags = tt->flags; |
| int i, ret, ttag, tclass, ndef, len; |
| const ASN1_VALUE *tval; |
| |
| /* |
| * If field is embedded then val needs fixing so it is a pointer to |
| * a pointer to a field. |
| */ |
| if (flags & ASN1_TFLG_EMBED) { |
| tval = (ASN1_VALUE *)pval; |
| pval = &tval; |
| } |
| /* |
| * Work out tag and class to use: tagging may come either from the |
| * template or the arguments, not both because this would create |
| * ambiguity. Additionally the iclass argument may contain some |
| * additional flags which should be noted and passed down to other |
| * levels. |
| */ |
| if (flags & ASN1_TFLG_TAG_MASK) { |
| /* Error if argument and template tagging */ |
| if (tag != -1) |
| /* FIXME: error code here */ |
| return -1; |
| /* Get tagging from template */ |
| ttag = tt->tag; |
| tclass = flags & ASN1_TFLG_TAG_CLASS; |
| } else if (tag != -1) { |
| /* No template tagging, get from arguments */ |
| ttag = tag; |
| tclass = iclass & ASN1_TFLG_TAG_CLASS; |
| } else { |
| ttag = -1; |
| tclass = 0; |
| } |
| /* |
| * Remove any class mask from iflag. |
| */ |
| iclass &= ~ASN1_TFLG_TAG_CLASS; |
| |
| /* |
| * At this point 'ttag' contains the outer tag to use, 'tclass' is the |
| * class and iclass is any flags passed to this function. |
| */ |
| |
| /* if template and arguments require ndef, use it */ |
| if ((flags & ASN1_TFLG_NDEF) && (iclass & ASN1_TFLG_NDEF)) |
| ndef = 2; |
| else |
| ndef = 1; |
| |
| if (flags & ASN1_TFLG_SK_MASK) { |
| /* SET OF, SEQUENCE OF */ |
| STACK_OF(const_ASN1_VALUE) *sk = (STACK_OF(const_ASN1_VALUE) *)*pval; |
| int isset, sktag, skaclass; |
| int skcontlen, sklen; |
| const ASN1_VALUE *skitem; |
| |
| if (*pval == NULL) |
| return 0; |
| |
| if (flags & ASN1_TFLG_SET_OF) { |
| isset = 1; |
| /* 2 means we reorder */ |
| if (flags & ASN1_TFLG_SEQUENCE_OF) |
| isset = 2; |
| } else |
| isset = 0; |
| |
| /* |
| * Work out inner tag value: if EXPLICIT or no tagging use underlying |
| * type. |
| */ |
| if ((ttag != -1) && !(flags & ASN1_TFLG_EXPTAG)) { |
| sktag = ttag; |
| skaclass = tclass; |
| } else { |
| skaclass = V_ASN1_UNIVERSAL; |
| if (isset) |
| sktag = V_ASN1_SET; |
| else |
| sktag = V_ASN1_SEQUENCE; |
| } |
| |
| /* Determine total length of items */ |
| skcontlen = 0; |
| for (i = 0; i < sk_const_ASN1_VALUE_num(sk); i++) { |
| skitem = sk_const_ASN1_VALUE_value(sk, i); |
| len = ASN1_item_ex_i2d(&skitem, NULL, ASN1_ITEM_ptr(tt->item), |
| -1, iclass); |
| if (len == -1 || (skcontlen > INT_MAX - len)) |
| return -1; |
| if (len == 0 && (tt->flags & ASN1_TFLG_OPTIONAL) == 0) { |
| ERR_raise(ERR_LIB_ASN1, ASN1_R_ILLEGAL_ZERO_CONTENT); |
| return -1; |
| } |
| skcontlen += len; |
| } |
| sklen = ASN1_object_size(ndef, skcontlen, sktag); |
| if (sklen == -1) |
| return -1; |
| /* If EXPLICIT need length of surrounding tag */ |
| if (flags & ASN1_TFLG_EXPTAG) |
| ret = ASN1_object_size(ndef, sklen, ttag); |
| else |
| ret = sklen; |
| |
| if (!out || ret == -1) |
| return ret; |
| |
| /* Now encode this lot... */ |
| /* EXPLICIT tag */ |
| if (flags & ASN1_TFLG_EXPTAG) |
| ASN1_put_object(out, ndef, sklen, ttag, tclass); |
| /* SET or SEQUENCE and IMPLICIT tag */ |
| ASN1_put_object(out, ndef, skcontlen, sktag, skaclass); |
| /* And the stuff itself */ |
| asn1_set_seq_out(sk, out, skcontlen, ASN1_ITEM_ptr(tt->item), |
| isset, iclass); |
| if (ndef == 2) { |
| ASN1_put_eoc(out); |
| if (flags & ASN1_TFLG_EXPTAG) |
| ASN1_put_eoc(out); |
| } |
| |
| return ret; |
| } |
| |
| if (flags & ASN1_TFLG_EXPTAG) { |
| /* EXPLICIT tagging */ |
| /* Find length of tagged item */ |
| i = ASN1_item_ex_i2d(pval, NULL, ASN1_ITEM_ptr(tt->item), -1, iclass); |
| if (i == 0) { |
| if ((tt->flags & ASN1_TFLG_OPTIONAL) == 0) { |
| ERR_raise(ERR_LIB_ASN1, ASN1_R_ILLEGAL_ZERO_CONTENT); |
| return -1; |
| } |
| return 0; |
| } |
| /* Find length of EXPLICIT tag */ |
| ret = ASN1_object_size(ndef, i, ttag); |
| if (out && ret != -1) { |
| /* Output tag and item */ |
| ASN1_put_object(out, ndef, i, ttag, tclass); |
| ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), -1, iclass); |
| if (ndef == 2) |
| ASN1_put_eoc(out); |
| } |
| return ret; |
| } |
| |
| /* Either normal or IMPLICIT tagging: combine class and flags */ |
| len = ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), |
| ttag, tclass | iclass); |
| if (len == 0 && (tt->flags & ASN1_TFLG_OPTIONAL) == 0) { |
| ERR_raise(ERR_LIB_ASN1, ASN1_R_ILLEGAL_ZERO_CONTENT); |
| return -1; |
| } |
| return len; |
| } |
| |
| /* Temporary structure used to hold DER encoding of items for SET OF */ |
| |
| typedef struct { |
| unsigned char *data; |
| int length; |
| const ASN1_VALUE *field; |
| } DER_ENC; |
| |
| static int der_cmp(const void *a, const void *b) |
| { |
| const DER_ENC *d1 = a, *d2 = b; |
| int cmplen, i; |
| cmplen = (d1->length < d2->length) ? d1->length : d2->length; |
| i = memcmp(d1->data, d2->data, cmplen); |
| if (i) |
| return i; |
| return d1->length - d2->length; |
| } |
| |
| /* Output the content octets of SET OF or SEQUENCE OF */ |
| |
| static int asn1_set_seq_out(STACK_OF(const_ASN1_VALUE) *sk, |
| unsigned char **out, |
| int skcontlen, const ASN1_ITEM *item, |
| int do_sort, int iclass) |
| { |
| int i, ret = 0; |
| const ASN1_VALUE *skitem; |
| unsigned char *tmpdat = NULL, *p = NULL; |
| DER_ENC *derlst = NULL, *tder; |
| |
| if (do_sort) { |
| /* Don't need to sort less than 2 items */ |
| if (sk_const_ASN1_VALUE_num(sk) < 2) |
| do_sort = 0; |
| else { |
| derlst = OPENSSL_malloc(sk_const_ASN1_VALUE_num(sk) |
| * sizeof(*derlst)); |
| if (derlst == NULL) { |
| ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE); |
| return 0; |
| } |
| tmpdat = OPENSSL_malloc(skcontlen); |
| if (tmpdat == NULL) { |
| ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| } |
| } |
| /* If not sorting just output each item */ |
| if (!do_sort) { |
| for (i = 0; i < sk_const_ASN1_VALUE_num(sk); i++) { |
| skitem = sk_const_ASN1_VALUE_value(sk, i); |
| ASN1_item_ex_i2d(&skitem, out, item, -1, iclass); |
| } |
| return 1; |
| } |
| p = tmpdat; |
| |
| /* Doing sort: build up a list of each member's DER encoding */ |
| for (i = 0, tder = derlst; i < sk_const_ASN1_VALUE_num(sk); i++, tder++) { |
| skitem = sk_const_ASN1_VALUE_value(sk, i); |
| tder->data = p; |
| tder->length = ASN1_item_ex_i2d(&skitem, &p, item, -1, iclass); |
| tder->field = skitem; |
| } |
| |
| /* Now sort them */ |
| qsort(derlst, sk_const_ASN1_VALUE_num(sk), sizeof(*derlst), der_cmp); |
| /* Output sorted DER encoding */ |
| p = *out; |
| for (i = 0, tder = derlst; i < sk_const_ASN1_VALUE_num(sk); i++, tder++) { |
| memcpy(p, tder->data, tder->length); |
| p += tder->length; |
| } |
| *out = p; |
| /* If do_sort is 2 then reorder the STACK */ |
| if (do_sort == 2) { |
| for (i = 0, tder = derlst; i < sk_const_ASN1_VALUE_num(sk); i++, tder++) |
| (void)sk_const_ASN1_VALUE_set(sk, i, tder->field); |
| } |
| ret = 1; |
| err: |
| OPENSSL_free(derlst); |
| OPENSSL_free(tmpdat); |
| return ret; |
| } |
| |
| static int asn1_i2d_ex_primitive(const ASN1_VALUE **pval, unsigned char **out, |
| const ASN1_ITEM *it, int tag, int aclass) |
| { |
| int len; |
| int utype; |
| int usetag; |
| int ndef = 0; |
| |
| utype = it->utype; |
| |
| /* |
| * Get length of content octets and maybe find out the underlying type. |
| */ |
| |
| len = asn1_ex_i2c(pval, NULL, &utype, it); |
| |
| /* |
| * If SEQUENCE, SET or OTHER then header is included in pseudo content |
| * octets so don't include tag+length. We need to check here because the |
| * call to asn1_ex_i2c() could change utype. |
| */ |
| if ((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) || |
| (utype == V_ASN1_OTHER)) |
| usetag = 0; |
| else |
| usetag = 1; |
| |
| /* -1 means omit type */ |
| |
| if (len == -1) |
| return 0; |
| |
| /* -2 return is special meaning use ndef */ |
| if (len == -2) { |
| ndef = 2; |
| len = 0; |
| } |
| |
| /* If not implicitly tagged get tag from underlying type */ |
| if (tag == -1) |
| tag = utype; |
| |
| /* Output tag+length followed by content octets */ |
| if (out) { |
| if (usetag) |
| ASN1_put_object(out, ndef, len, tag, aclass); |
| asn1_ex_i2c(pval, *out, &utype, it); |
| if (ndef) |
| ASN1_put_eoc(out); |
| else |
| *out += len; |
| } |
| |
| if (usetag) |
| return ASN1_object_size(ndef, len, tag); |
| return len; |
| } |
| |
| /* Produce content octets from a structure */ |
| |
| static int asn1_ex_i2c(const ASN1_VALUE **pval, unsigned char *cout, int *putype, |
| const ASN1_ITEM *it) |
| { |
| ASN1_BOOLEAN *tbool = NULL; |
| ASN1_STRING *strtmp; |
| ASN1_OBJECT *otmp; |
| int utype; |
| const unsigned char *cont; |
| unsigned char c; |
| int len; |
| const ASN1_PRIMITIVE_FUNCS *pf; |
| pf = it->funcs; |
| if (pf && pf->prim_i2c) |
| return pf->prim_i2c(pval, cout, putype, it); |
| |
| /* Should type be omitted? */ |
| if ((it->itype != ASN1_ITYPE_PRIMITIVE) |
| || (it->utype != V_ASN1_BOOLEAN)) { |
| if (*pval == NULL) |
| return -1; |
| } |
| |
| if (it->itype == ASN1_ITYPE_MSTRING) { |
| /* If MSTRING type set the underlying type */ |
| strtmp = (ASN1_STRING *)*pval; |
| utype = strtmp->type; |
| *putype = utype; |
| } else if (it->utype == V_ASN1_ANY) { |
| /* If ANY set type and pointer to value */ |
| ASN1_TYPE *typ; |
| typ = (ASN1_TYPE *)*pval; |
| utype = typ->type; |
| *putype = utype; |
| pval = (const ASN1_VALUE **)&typ->value.asn1_value; /* actually is const */ |
| } else |
| utype = *putype; |
| |
| switch (utype) { |
| case V_ASN1_OBJECT: |
| otmp = (ASN1_OBJECT *)*pval; |
| cont = otmp->data; |
| len = otmp->length; |
| if (cont == NULL || len == 0) |
| return -1; |
| break; |
| |
| case V_ASN1_NULL: |
| cont = NULL; |
| len = 0; |
| break; |
| |
| case V_ASN1_BOOLEAN: |
| tbool = (ASN1_BOOLEAN *)pval; |
| if (*tbool == -1) |
| return -1; |
| if (it->utype != V_ASN1_ANY) { |
| /* |
| * Default handling if value == size field then omit |
| */ |
| if (*tbool && (it->size > 0)) |
| return -1; |
| if (!*tbool && !it->size) |
| return -1; |
| } |
| c = (unsigned char)*tbool; |
| cont = &c; |
| len = 1; |
| break; |
| |
| case V_ASN1_BIT_STRING: |
| return ossl_i2c_ASN1_BIT_STRING((ASN1_BIT_STRING *)*pval, |
| cout ? &cout : NULL); |
| |
| case V_ASN1_INTEGER: |
| case V_ASN1_ENUMERATED: |
| /* |
| * These are all have the same content format as ASN1_INTEGER |
| */ |
| return ossl_i2c_ASN1_INTEGER((ASN1_INTEGER *)*pval, cout ? &cout : NULL); |
| |
| case V_ASN1_OCTET_STRING: |
| case V_ASN1_NUMERICSTRING: |
| case V_ASN1_PRINTABLESTRING: |
| case V_ASN1_T61STRING: |
| case V_ASN1_VIDEOTEXSTRING: |
| case V_ASN1_IA5STRING: |
| case V_ASN1_UTCTIME: |
| case V_ASN1_GENERALIZEDTIME: |
| case V_ASN1_GRAPHICSTRING: |
| case V_ASN1_VISIBLESTRING: |
| case V_ASN1_GENERALSTRING: |
| case V_ASN1_UNIVERSALSTRING: |
| case V_ASN1_BMPSTRING: |
| case V_ASN1_UTF8STRING: |
| case V_ASN1_SEQUENCE: |
| case V_ASN1_SET: |
| default: |
| /* All based on ASN1_STRING and handled the same */ |
| strtmp = (ASN1_STRING *)*pval; |
| /* Special handling for NDEF */ |
| if ((it->size == ASN1_TFLG_NDEF) |
| && (strtmp->flags & ASN1_STRING_FLAG_NDEF)) { |
| if (cout) { |
| strtmp->data = cout; |
| strtmp->length = 0; |
| } |
| /* Special return code */ |
| return -2; |
| } |
| cont = strtmp->data; |
| len = strtmp->length; |
| |
| break; |
| |
| } |
| if (cout && len) |
| memcpy(cout, cont, len); |
| return len; |
| } |
