/* $OpenBSD: tasn_enc.c,v 1.23 2020/12/08 15:06:42 tb Exp $ */ /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL * project 2000. */ /* ==================================================================== * Copyright (c) 2000-2004 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * licensing@OpenSSL.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #include #include #include #include #include #include static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass); static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *sk, unsigned char **out, int skcontlen, const ASN1_ITEM *item, int do_sort, int iclass); static int asn1_template_ex_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_TEMPLATE *tt, int tag, int aclass); static int asn1_item_flags_i2d(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it, int flags); static int asn1_ex_i2c(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(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(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(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it, int flags) { if (out && !*out) { unsigned char *p, *buf; int len; len = ASN1_item_ex_i2d(&val, NULL, it, -1, flags); if (len <= 0) return len; buf = malloc(len); if (!buf) 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(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_cb *asn1_cb = NULL; if ((it->itype != ASN1_ITYPE_PRIMITIVE) && !*pval) return 0; if (aux && aux->asn1_cb) asn1_cb = aux->asn1_cb; 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); break; 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) { ASN1error(ASN1_R_BAD_TEMPLATE); return 0; } 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) { ASN1error(ASN1_R_BAD_TEMPLATE); return 0; } if (asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it, NULL)) return 0; i = asn1_get_choice_selector(pval, it); if ((i >= 0) && (i < it->tcount)) { ASN1_VALUE **pchval; const ASN1_TEMPLATE *chtt; chtt = it->templates + i; pchval = asn1_get_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 = 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; ASN1_VALUE **pseqval; seqtt = asn1_do_adb(pval, tt, 1); if (!seqtt) return 0; pseqval = asn1_get_field_ptr(pval, seqtt); /* FIXME: check for errors in enhanced version */ seqcontlen += asn1_template_ex_i2d(pseqval, NULL, seqtt, -1, aclass); } seqlen = ASN1_object_size(ndef, seqcontlen, tag); if (!out) 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; ASN1_VALUE **pseqval; seqtt = asn1_do_adb(pval, tt, 1); if (!seqtt) return 0; pseqval = asn1_get_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; } int ASN1_template_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_TEMPLATE *tt) { return asn1_template_ex_i2d(pval, out, tt, -1, 0); } static int asn1_template_ex_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_TEMPLATE *tt, int tag, int iclass) { int i, ret, flags, ttag, tclass, ndef; flags = tt->flags; /* 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(ASN1_VALUE) *sk = (STACK_OF(ASN1_VALUE) *)*pval; int isset, sktag, skaclass; int skcontlen, sklen; ASN1_VALUE *skitem; if (!*pval) 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_ASN1_VALUE_num(sk); i++) { skitem = sk_ASN1_VALUE_value(sk, i); skcontlen += ASN1_item_ex_i2d(&skitem, NULL, tt->item, -1, iclass); } sklen = ASN1_object_size(ndef, skcontlen, sktag); /* If EXPLICIT need length of surrounding tag */ if (flags & ASN1_TFLG_EXPTAG) ret = ASN1_object_size(ndef, sklen, ttag); else ret = sklen; if (!out) 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, 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, tt->item, -1, iclass); if (!i) return 0; /* Find length of EXPLICIT tag */ ret = ASN1_object_size(ndef, i, ttag); if (out) { /* Output tag and item */ ASN1_put_object(out, ndef, i, ttag, tclass); ASN1_item_ex_i2d(pval, out, tt->item, -1, iclass); if (ndef == 2) ASN1_put_eoc(out); } return ret; } /* Either normal or IMPLICIT tagging: combine class and flags */ return ASN1_item_ex_i2d(pval, out, tt->item, ttag, tclass | iclass); } /* Temporary structure used to hold DER encoding of items for SET OF */ typedef struct { unsigned char *data; int length; 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(ASN1_VALUE) *sk, unsigned char **out, int skcontlen, const ASN1_ITEM *item, int do_sort, int iclass) { int i; 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_ASN1_VALUE_num(sk) < 2) do_sort = 0; else { derlst = reallocarray(NULL, sk_ASN1_VALUE_num(sk), sizeof(*derlst)); tmpdat = malloc(skcontlen); if (!derlst || !tmpdat) { free(derlst); free(tmpdat); return 0; } } } /* If not sorting just output each item */ if (!do_sort) { for (i = 0; i < sk_ASN1_VALUE_num(sk); i++) { skitem = sk_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_ASN1_VALUE_num(sk); i++, tder++) { skitem = sk_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_ASN1_VALUE_num(sk), sizeof(*derlst), der_cmp); /* Output sorted DER encoding */ p = *out; for (i = 0, tder = derlst; i < sk_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_ASN1_VALUE_num(sk); i++, tder++) (void)sk_ASN1_VALUE_set(sk, i, tder->field); } free(derlst); free(tmpdat); return 1; } static int asn1_i2d_ex_primitive(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(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; if (it->funcs != NULL) { const ASN1_PRIMITIVE_FUNCS *pf = it->funcs; if (pf->prim_i2c == NULL) return -1; 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) 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 = &typ->value.asn1_value; } else utype = *putype; switch (utype) { case V_ASN1_OBJECT: otmp = (ASN1_OBJECT *)*pval; cont = otmp->data; len = otmp->length; 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 i2c_ASN1_BIT_STRING((ASN1_BIT_STRING *)*pval, cout ? &cout : NULL); break; case V_ASN1_INTEGER: case V_ASN1_ENUMERATED: /* These are all have the same content format * as ASN1_INTEGER */ return i2c_ASN1_INTEGER((ASN1_INTEGER *)*pval, cout ? &cout : NULL); break; 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; }