| // Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include <openssl/asn1.h> |
| #include <openssl/asn1t.h> |
| #include <openssl/bytestring.h> |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| #include <openssl/pool.h> |
| |
| #include <assert.h> |
| #include <limits.h> |
| #include <string.h> |
| |
| #include "../bytestring/internal.h" |
| #include "../internal.h" |
| #include "internal.h" |
| |
| // Constructed types with a recursive definition (such as can be found in PKCS7) |
| // could eventually exceed the stack given malicious input with excessive |
| // recursion. Therefore we limit the stack depth. This is the maximum number of |
| // recursive invocations of asn1_item_embed_d2i(). |
| #define ASN1_MAX_CONSTRUCTED_NEST 30 |
| |
| static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, |
| char *cst, const unsigned char **in, long len, |
| int exptag, int expclass, char opt); |
| |
| static int asn1_template_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, |
| long len, const ASN1_TEMPLATE *tt, char opt, |
| int depth); |
| static int asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in, |
| long len, const ASN1_TEMPLATE *tt, char opt, |
| int depth); |
| static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in, |
| long len, const ASN1_ITEM *it, int tag, |
| int aclass, char opt); |
| static int asn1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, |
| long len, const ASN1_ITEM *it, int tag, int aclass, |
| char opt, int depth); |
| |
| unsigned long ASN1_tag2bit(int tag) { |
| switch (tag) { |
| case V_ASN1_BIT_STRING: |
| return B_ASN1_BIT_STRING; |
| case V_ASN1_OCTET_STRING: |
| return B_ASN1_OCTET_STRING; |
| case V_ASN1_UTF8STRING: |
| return B_ASN1_UTF8STRING; |
| case V_ASN1_SEQUENCE: |
| return B_ASN1_SEQUENCE; |
| case V_ASN1_NUMERICSTRING: |
| return B_ASN1_NUMERICSTRING; |
| case V_ASN1_PRINTABLESTRING: |
| return B_ASN1_PRINTABLESTRING; |
| case V_ASN1_T61STRING: |
| return B_ASN1_T61STRING; |
| case V_ASN1_VIDEOTEXSTRING: |
| return B_ASN1_VIDEOTEXSTRING; |
| case V_ASN1_IA5STRING: |
| return B_ASN1_IA5STRING; |
| case V_ASN1_UTCTIME: |
| return B_ASN1_UTCTIME; |
| case V_ASN1_GENERALIZEDTIME: |
| return B_ASN1_GENERALIZEDTIME; |
| case V_ASN1_GRAPHICSTRING: |
| return B_ASN1_GRAPHICSTRING; |
| case V_ASN1_ISO64STRING: |
| return B_ASN1_ISO64STRING; |
| case V_ASN1_GENERALSTRING: |
| return B_ASN1_GENERALSTRING; |
| case V_ASN1_UNIVERSALSTRING: |
| return B_ASN1_UNIVERSALSTRING; |
| case V_ASN1_BMPSTRING: |
| return B_ASN1_BMPSTRING; |
| default: |
| return 0; |
| } |
| } |
| |
| // Decode an ASN1 item, this currently behaves just like a standard 'd2i' |
| // function. 'in' points to a buffer to read the data from, in future we |
| // will have more advanced versions that can input data a piece at a time and |
| // this will simply be a special case. |
| |
| ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, |
| const ASN1_ITEM *it) { |
| ASN1_VALUE *ret = NULL; |
| if (asn1_item_ex_d2i(&ret, in, len, it, /*tag=*/-1, /*aclass=*/0, /*opt=*/0, |
| /*depth=*/0) <= 0) { |
| // Clean up, in case the caller left a partial object. |
| // |
| // TODO(davidben): I don't think it can leave one, but the codepaths below |
| // are a bit inconsistent. Revisit this when rewriting this function. |
| ASN1_item_ex_free(&ret, it); |
| } |
| |
| // If the caller supplied an output pointer, free the old one and replace it |
| // with |ret|. This differs from OpenSSL slightly in that we don't support |
| // object reuse. We run this on both success and failure. On failure, even |
| // with object reuse, OpenSSL destroys the previous object. |
| if (pval != NULL) { |
| ASN1_item_ex_free(pval, it); |
| *pval = ret; |
| } |
| return ret; |
| } |
| |
| // Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and |
| // tag mismatch return -1 to handle OPTIONAL |
| // |
| // TODO(davidben): Historically, all functions in this file had to account for |
| // |*pval| containing an arbitrary existing value. This is no longer the case |
| // because |ASN1_item_d2i| now always starts from NULL. As part of rewriting |
| // this function, take the simplified assumptions into account. Though we must |
| // still account for the internal calls to |ASN1_item_ex_new|. |
| |
| static int asn1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, |
| long len, const ASN1_ITEM *it, int tag, int aclass, |
| char opt, int depth) { |
| const ASN1_TEMPLATE *tt, *errtt = NULL; |
| const unsigned char *p = NULL, *q; |
| unsigned char oclass; |
| char cst, isopt; |
| int i; |
| int otag; |
| int ret = 0; |
| ASN1_VALUE **pchptr; |
| if (!pval) { |
| return 0; |
| } |
| if (len < 0) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_BUFFER_TOO_SMALL); |
| goto err; |
| } |
| |
| // Bound |len| to comfortably fit in an int. Lengths in this module often |
| // switch between int and long without overflow checks. |
| if (len > INT_MAX / 2) { |
| len = INT_MAX / 2; |
| } |
| |
| if (++depth > ASN1_MAX_CONSTRUCTED_NEST) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_TOO_DEEP); |
| goto err; |
| } |
| |
| switch (it->itype) { |
| case ASN1_ITYPE_PRIMITIVE: |
| if (it->templates) { |
| // tagging or OPTIONAL is currently illegal on an item template |
| // because the flags can't get passed down. In practice this |
| // isn't a problem: we include the relevant flags from the item |
| // template in the template itself. |
| if ((tag != -1) || opt) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE); |
| goto err; |
| } |
| return asn1_template_ex_d2i(pval, in, len, it->templates, opt, depth); |
| } |
| return asn1_d2i_ex_primitive(pval, in, len, it, tag, aclass, opt); |
| |
| 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) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_TEMPLATE); |
| goto err; |
| } |
| |
| p = *in; |
| // Just read in tag and class |
| ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, &p, len, -1, 0, 1); |
| if (!ret) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } |
| |
| // Must be UNIVERSAL class |
| if (oclass != V_ASN1_UNIVERSAL) { |
| // If OPTIONAL, assume this is OK |
| if (opt) { |
| return -1; |
| } |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_MSTRING_NOT_UNIVERSAL); |
| goto err; |
| } |
| // Check tag matches bit map |
| if (!(ASN1_tag2bit(otag) & it->utype)) { |
| // If OPTIONAL, assume this is OK |
| if (opt) { |
| return -1; |
| } |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_MSTRING_WRONG_TAG); |
| goto err; |
| } |
| return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0); |
| |
| case ASN1_ITYPE_EXTERN: { |
| // We don't support implicit tagging with external types. |
| if (tag != -1) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_TEMPLATE); |
| goto err; |
| } |
| const ASN1_EXTERN_FUNCS *ef = |
| reinterpret_cast<const ASN1_EXTERN_FUNCS *>(it->funcs); |
| CBS cbs; |
| CBS_init(&cbs, *in, len); |
| CBS copy = cbs; |
| if (!ef->asn1_ex_parse(pval, &cbs, it, opt)) { |
| goto err; |
| } |
| *in = CBS_data(&cbs); |
| // Check whether the function skipped an optional element. |
| // |
| // TODO(crbug.com/42290418): Switch the rest of this function to |
| // |asn1_ex_parse|'s calling convention. |
| return CBS_len(&cbs) == CBS_len(©) ? -1 : 1; |
| } |
| |
| 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) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_TEMPLATE); |
| goto err; |
| } |
| |
| const ASN1_AUX *aux = reinterpret_cast<const ASN1_AUX *>(it->funcs); |
| ASN1_aux_cb *asn1_cb = aux != NULL ? aux->asn1_cb : NULL; |
| if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) { |
| goto auxerr; |
| } |
| |
| if (*pval) { |
| // Free up and zero CHOICE value if initialised |
| i = asn1_get_choice_selector(pval, it); |
| if ((i >= 0) && (i < it->tcount)) { |
| tt = it->templates + i; |
| pchptr = asn1_get_field_ptr(pval, tt); |
| ASN1_template_free(pchptr, tt); |
| asn1_set_choice_selector(pval, -1, it); |
| } |
| } else if (!ASN1_item_ex_new(pval, it)) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } |
| // CHOICE type, try each possibility in turn |
| p = *in; |
| for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { |
| pchptr = asn1_get_field_ptr(pval, tt); |
| // We mark field as OPTIONAL so its absence can be recognised. |
| ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, depth); |
| // If field not present, try the next one |
| if (ret == -1) { |
| continue; |
| } |
| // If positive return, read OK, break loop |
| if (ret > 0) { |
| break; |
| } |
| // Otherwise must be an ASN1 parsing error |
| errtt = tt; |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } |
| |
| // Did we fall off the end without reading anything? |
| if (i == it->tcount) { |
| // If OPTIONAL, this is OK |
| if (opt) { |
| // Free and zero it |
| ASN1_item_ex_free(pval, it); |
| return -1; |
| } |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NO_MATCHING_CHOICE_TYPE); |
| goto err; |
| } |
| |
| asn1_set_choice_selector(pval, i, it); |
| if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) { |
| goto auxerr; |
| } |
| *in = p; |
| return 1; |
| } |
| |
| case ASN1_ITYPE_SEQUENCE: { |
| p = *in; |
| |
| // If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL |
| if (tag == -1) { |
| tag = V_ASN1_SEQUENCE; |
| aclass = V_ASN1_UNIVERSAL; |
| } |
| // Get SEQUENCE length and update len, p |
| ret = asn1_check_tlen(&len, NULL, NULL, &cst, &p, len, tag, aclass, opt); |
| if (!ret) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } else if (ret == -1) { |
| return -1; |
| } |
| if (!cst) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_SEQUENCE_NOT_CONSTRUCTED); |
| goto err; |
| } |
| |
| if (!*pval && !ASN1_item_ex_new(pval, it)) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } |
| |
| const ASN1_AUX *aux = reinterpret_cast<const ASN1_AUX *>(it->funcs); |
| ASN1_aux_cb *asn1_cb = aux != NULL ? aux->asn1_cb : NULL; |
| if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL)) { |
| goto auxerr; |
| } |
| |
| // Free up and zero any ADB found |
| for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { |
| if (tt->flags & ASN1_TFLG_ADB_MASK) { |
| const ASN1_TEMPLATE *seqtt; |
| ASN1_VALUE **pseqval; |
| seqtt = asn1_do_adb(pval, tt, 0); |
| if (seqtt == NULL) { |
| continue; |
| } |
| pseqval = asn1_get_field_ptr(pval, seqtt); |
| ASN1_template_free(pseqval, seqtt); |
| } |
| } |
| |
| // Get each field entry |
| for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) { |
| const ASN1_TEMPLATE *seqtt; |
| ASN1_VALUE **pseqval; |
| seqtt = asn1_do_adb(pval, tt, 1); |
| if (seqtt == NULL) { |
| goto err; |
| } |
| pseqval = asn1_get_field_ptr(pval, seqtt); |
| // Have we ran out of data? |
| if (!len) { |
| break; |
| } |
| q = p; |
| // This determines the OPTIONAL flag value. The field cannot be |
| // omitted if it is the last of a SEQUENCE and there is still |
| // data to be read. This isn't strictly necessary but it |
| // increases efficiency in some cases. |
| if (i == (it->tcount - 1)) { |
| isopt = 0; |
| } else { |
| isopt = (seqtt->flags & ASN1_TFLG_OPTIONAL) != 0; |
| } |
| // attempt to read in field, allowing each to be OPTIONAL |
| |
| ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, depth); |
| if (!ret) { |
| errtt = seqtt; |
| goto err; |
| } else if (ret == -1) { |
| // OPTIONAL component absent. Free and zero the field. |
| ASN1_template_free(pseqval, seqtt); |
| continue; |
| } |
| // Update length |
| len -= p - q; |
| } |
| |
| // Check all data read |
| if (len) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_SEQUENCE_LENGTH_MISMATCH); |
| goto err; |
| } |
| |
| // If we get here we've got no more data in the SEQUENCE, however we |
| // may not have read all fields so check all remaining are OPTIONAL |
| // and clear any that are. |
| for (; i < it->tcount; tt++, i++) { |
| const ASN1_TEMPLATE *seqtt; |
| seqtt = asn1_do_adb(pval, tt, 1); |
| if (seqtt == NULL) { |
| goto err; |
| } |
| if (seqtt->flags & ASN1_TFLG_OPTIONAL) { |
| ASN1_VALUE **pseqval; |
| pseqval = asn1_get_field_ptr(pval, seqtt); |
| ASN1_template_free(pseqval, seqtt); |
| } else { |
| errtt = seqtt; |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_FIELD_MISSING); |
| goto err; |
| } |
| } |
| // Save encoding |
| if (!asn1_enc_save(pval, *in, p - *in, it)) { |
| goto auxerr; |
| } |
| if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL)) { |
| goto auxerr; |
| } |
| *in = p; |
| return 1; |
| } |
| |
| default: |
| return 0; |
| } |
| auxerr: |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_AUX_ERROR); |
| err: |
| ASN1_item_ex_free(pval, it); |
| if (errtt) { |
| ERR_add_error_data(4, "Field=", errtt->field_name, ", Type=", it->sname); |
| } else { |
| ERR_add_error_data(2, "Type=", it->sname); |
| } |
| return 0; |
| } |
| |
| int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, |
| const ASN1_ITEM *it, int tag, int aclass, char opt) { |
| return asn1_item_ex_d2i(pval, in, len, it, tag, aclass, opt, /*depth=*/0); |
| } |
| |
| // Templates are handled with two separate functions. One handles any |
| // EXPLICIT tag and the other handles the rest. |
| |
| static int asn1_template_ex_d2i(ASN1_VALUE **val, const unsigned char **in, |
| long inlen, const ASN1_TEMPLATE *tt, char opt, |
| int depth) { |
| int aclass; |
| int ret; |
| long len; |
| const unsigned char *p, *q; |
| if (!val) { |
| return 0; |
| } |
| uint32_t flags = tt->flags; |
| aclass = flags & ASN1_TFLG_TAG_CLASS; |
| |
| p = *in; |
| |
| // Check if EXPLICIT tag expected |
| if (flags & ASN1_TFLG_EXPTAG) { |
| char cst; |
| // Need to work out amount of data available to the inner content and |
| // where it starts: so read in EXPLICIT header to get the info. |
| ret = asn1_check_tlen(&len, NULL, NULL, &cst, &p, inlen, tt->tag, aclass, |
| opt); |
| q = p; |
| if (!ret) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| return 0; |
| } else if (ret == -1) { |
| return -1; |
| } |
| if (!cst) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED); |
| return 0; |
| } |
| // We've found the field so it can't be OPTIONAL now |
| ret = asn1_template_noexp_d2i(val, &p, len, tt, /*opt=*/0, depth); |
| if (!ret) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| return 0; |
| } |
| // We read the field in OK so update length |
| len -= p - q; |
| // Check for trailing data. |
| if (len) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_EXPLICIT_LENGTH_MISMATCH); |
| goto err; |
| } |
| } else { |
| return asn1_template_noexp_d2i(val, in, inlen, tt, opt, depth); |
| } |
| |
| *in = p; |
| return 1; |
| |
| err: |
| ASN1_template_free(val, tt); |
| return 0; |
| } |
| |
| static int asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in, |
| long len, const ASN1_TEMPLATE *tt, char opt, |
| int depth) { |
| int aclass; |
| int ret; |
| const unsigned char *p; |
| if (!val) { |
| return 0; |
| } |
| uint32_t flags = tt->flags; |
| aclass = flags & ASN1_TFLG_TAG_CLASS; |
| |
| p = *in; |
| |
| if (flags & ASN1_TFLG_SK_MASK) { |
| // SET OF, SEQUENCE OF |
| int sktag, skaclass; |
| // First work out expected inner tag value |
| if (flags & ASN1_TFLG_IMPTAG) { |
| sktag = tt->tag; |
| skaclass = aclass; |
| } else { |
| skaclass = V_ASN1_UNIVERSAL; |
| if (flags & ASN1_TFLG_SET_OF) { |
| sktag = V_ASN1_SET; |
| } else { |
| sktag = V_ASN1_SEQUENCE; |
| } |
| } |
| // Get the tag |
| ret = |
| asn1_check_tlen(&len, NULL, NULL, NULL, &p, len, sktag, skaclass, opt); |
| if (!ret) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| return 0; |
| } else if (ret == -1) { |
| return -1; |
| } |
| if (!*val) { |
| *val = (ASN1_VALUE *)sk_ASN1_VALUE_new_null(); |
| } else { |
| // We've got a valid STACK: free up any items present |
| STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val; |
| ASN1_VALUE *vtmp; |
| while (sk_ASN1_VALUE_num(sktmp) > 0) { |
| vtmp = sk_ASN1_VALUE_pop(sktmp); |
| ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item)); |
| } |
| } |
| |
| if (!*val) { |
| goto err; |
| } |
| |
| // Read as many items as we can |
| while (len > 0) { |
| ASN1_VALUE *skfield; |
| const unsigned char *q = p; |
| skfield = NULL; |
| if (!asn1_item_ex_d2i(&skfield, &p, len, ASN1_ITEM_ptr(tt->item), |
| /*tag=*/-1, /*aclass=*/0, /*opt=*/0, depth)) { |
| ASN1_item_ex_free(&skfield, ASN1_ITEM_ptr(tt->item)); |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } |
| len -= p - q; |
| if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) { |
| ASN1_item_ex_free(&skfield, ASN1_ITEM_ptr(tt->item)); |
| goto err; |
| } |
| } |
| } else if (flags & ASN1_TFLG_IMPTAG) { |
| // IMPLICIT tagging |
| ret = asn1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), tt->tag, |
| aclass, opt, depth); |
| if (!ret) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } else if (ret == -1) { |
| return -1; |
| } |
| } else { |
| // Nothing special |
| ret = asn1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), /*tag=*/-1, |
| /*aclass=*/0, opt, depth); |
| if (!ret) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR); |
| goto err; |
| } else if (ret == -1) { |
| return -1; |
| } |
| } |
| |
| *in = p; |
| return 1; |
| |
| err: |
| ASN1_template_free(val, tt); |
| return 0; |
| } |
| |
| // TODO(crbug.com/42290418): Switch the whole file to use a CBS-based calling |
| // convention. |
| static int asn1_d2i_ex_primitive_cbs(ASN1_VALUE **pval, CBS *cbs, |
| const ASN1_ITEM *it, int tag, int aclass, |
| char opt); |
| |
| // asn1_d2i_ex_primitive returns one on success, zero on error, and -1 if an |
| // optional value was skipped. |
| static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in, |
| long inlen, const ASN1_ITEM *it, int tag, |
| int aclass, char opt) { |
| CBS cbs; |
| CBS_init(&cbs, *in, inlen); |
| int ret = asn1_d2i_ex_primitive_cbs(pval, &cbs, it, tag, aclass, opt); |
| if (ret <= 0) { |
| return ret; |
| } |
| *in = CBS_data(&cbs); |
| return 1; |
| } |
| |
| static ASN1_STRING *ensure_string(ASN1_VALUE **pval) { |
| if (*pval) { |
| return (ASN1_STRING *)*pval; |
| } |
| ASN1_STRING *str = ASN1_STRING_new(); |
| if (str == nullptr) { |
| return nullptr; |
| } |
| *pval = (ASN1_VALUE *)str; |
| return str; |
| } |
| |
| static int asn1_d2i_ex_primitive_cbs(ASN1_VALUE **pval, CBS *cbs, |
| const ASN1_ITEM *it, int tag, int aclass, |
| char opt) { |
| // Historically, |it->funcs| for primitive types contained an |
| // |ASN1_PRIMITIVE_FUNCS| table of callbacks. |
| assert(it->funcs == NULL); |
| |
| int utype; |
| assert(it->itype == ASN1_ITYPE_PRIMITIVE || it->itype == ASN1_ITYPE_MSTRING); |
| if (it->itype == ASN1_ITYPE_MSTRING) { |
| // MSTRING passes utype in |tag|, normally used for implicit tagging. |
| utype = tag; |
| tag = -1; |
| } else { |
| utype = it->utype; |
| } |
| |
| // Handle ANY types. |
| if (utype == V_ASN1_ANY || utype == V_ASN1_ANY_AS_STRING) { |
| if (tag >= 0) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_TAGGED_ANY); |
| return 0; |
| } |
| if (opt && CBS_len(cbs) == 0) { |
| return -1; // Omitted OPTIONAL value. |
| } |
| } |
| if (utype == V_ASN1_ANY) { |
| ASN1_TYPE *typ; |
| if (!*pval) { |
| typ = ASN1_TYPE_new(); |
| if (typ == NULL) { |
| return 0; |
| } |
| *pval = (ASN1_VALUE *)typ; |
| } else { |
| typ = (ASN1_TYPE *)*pval; |
| } |
| return asn1_parse_any(cbs, typ); |
| } |
| if (utype == V_ASN1_ANY_AS_STRING) { |
| ASN1_STRING *str = ensure_string(pval); |
| if (str == nullptr) { |
| return 0; |
| } |
| return asn1_parse_any_as_string(cbs, str); |
| } |
| |
| // Convert the crypto/asn1 tag into a CBS one. |
| if (tag == -1) { |
| tag = utype; |
| aclass = V_ASN1_UNIVERSAL; |
| } |
| |
| // All edge cases of |utype| should have been handled already. |utype| is now |
| // either a primitive |ASN1_ITEM|, handled by |DECLARE_ASN1_ITEM|, or a |
| // multistring option with a corresponding |B_ASN1_*| constant. |
| assert(utype >= 0 && utype <= V_ASN1_MAX_UNIVERSAL); |
| CBS_ASN1_TAG cbs_tag = |
| (static_cast<CBS_ASN1_TAG>(aclass) << CBS_ASN1_TAG_SHIFT) | |
| static_cast<CBS_ASN1_TAG>(tag); |
| if (utype == V_ASN1_SEQUENCE || utype == V_ASN1_SET) { |
| cbs_tag |= CBS_ASN1_CONSTRUCTED; |
| } |
| |
| if (opt && !CBS_peek_asn1_tag(cbs, cbs_tag)) { |
| return -1; // Omitted OPTIONAL value. |
| } |
| |
| // Handle non-|ASN1_STRING| types. |
| switch (utype) { |
| case V_ASN1_OBJECT: { |
| bssl::UniquePtr<ASN1_OBJECT> obj(asn1_parse_object(cbs, cbs_tag)); |
| if (obj == nullptr) { |
| return 0; |
| } |
| ASN1_OBJECT_free((ASN1_OBJECT *)*pval); |
| *pval = (ASN1_VALUE *)obj.release(); |
| return 1; |
| } |
| case V_ASN1_NULL: { |
| CBS null; |
| if (!CBS_get_asn1(cbs, &null, cbs_tag)) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_DECODE_ERROR); |
| return 0; |
| } |
| if (CBS_len(&null) != 0) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_NULL_IS_WRONG_LENGTH); |
| return 0; |
| } |
| *pval = (ASN1_VALUE *)1; |
| return 1; |
| } |
| case V_ASN1_BOOLEAN: { |
| CBS child; |
| if (!CBS_get_asn1(cbs, &child, cbs_tag)) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_DECODE_ERROR); |
| return 0; |
| } |
| // TODO(crbug.com/42290221): Reject invalid BOOLEAN encodings and just |
| // call |CBS_get_asn1_bool|. |
| if (CBS_len(&child) != 1) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_BOOLEAN_IS_WRONG_LENGTH); |
| return 0; |
| } |
| ASN1_BOOLEAN *tbool; |
| tbool = (ASN1_BOOLEAN *)pval; |
| *tbool = CBS_data(&child)[0]; |
| return 1; |
| } |
| } |
| |
| // All other types as an |ASN1_STRING| representation. |
| ASN1_STRING *str = ensure_string(pval); |
| if (str == nullptr) { |
| return 0; |
| } |
| |
| switch (utype) { |
| case V_ASN1_BIT_STRING: |
| return asn1_parse_bit_string(cbs, str, cbs_tag); |
| case V_ASN1_INTEGER: |
| return asn1_parse_integer(cbs, str, cbs_tag); |
| case V_ASN1_ENUMERATED: |
| return asn1_parse_enumerated(cbs, str, cbs_tag); |
| case V_ASN1_UNIVERSALSTRING: |
| return asn1_parse_universal_string(cbs, str, cbs_tag); |
| case V_ASN1_BMPSTRING: |
| return asn1_parse_bmp_string(cbs, str, cbs_tag); |
| case V_ASN1_UTF8STRING: |
| return asn1_parse_utf8_string(cbs, str, cbs_tag); |
| case V_ASN1_UTCTIME: |
| // TODO(crbug.com/42290221): Reject timezone offsets. We need to parse |
| // invalid timestamps in |X509| objects, but that parser no longer uses |
| // this code. |
| return asn1_parse_utc_time(cbs, str, cbs_tag, |
| /*allow_timezone_offset=*/1); |
| case V_ASN1_GENERALIZEDTIME: |
| return asn1_parse_generalized_time(cbs, str, cbs_tag); |
| 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_GRAPHICSTRING: |
| case V_ASN1_VISIBLESTRING: |
| case V_ASN1_GENERALSTRING: |
| // T61String is parsed as Latin-1, so all byte strings are valid. The |
| // others we currently do not enforce. |
| // |
| // TODO(crbug.com/42290290): Enforce the encoding of the other string |
| // types. |
| if (!asn1_parse_octet_string(cbs, str, cbs_tag)) { |
| return 0; |
| } |
| str->type = utype; |
| return 1; |
| case V_ASN1_SEQUENCE: { |
| // Save the entire element in the string. |
| CBS elem; |
| if (!CBS_get_asn1_element(cbs, &elem, cbs_tag)) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_DECODE_ERROR); |
| return 0; |
| } |
| str->type = V_ASN1_SEQUENCE; |
| return ASN1_STRING_set(str, CBS_data(&elem), CBS_len(&elem)); |
| } |
| default: |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_TEMPLATE); |
| return 0; |
| } |
| } |
| |
| // Check an ASN1 tag and length: a bit like ASN1_get_object but it |
| // checks the expected tag. |
| |
| static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, |
| char *cst, const unsigned char **in, long len, |
| int exptag, int expclass, char opt) { |
| int i; |
| int ptag, pclass; |
| long plen; |
| const unsigned char *p; |
| p = *in; |
| |
| i = ASN1_get_object(&p, &plen, &ptag, &pclass, len); |
| if (i & 0x80) { |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_OBJECT_HEADER); |
| return 0; |
| } |
| if (exptag >= 0) { |
| if ((exptag != ptag) || (expclass != pclass)) { |
| // If type is OPTIONAL, not an error: indicate missing type. |
| if (opt) { |
| return -1; |
| } |
| OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_TAG); |
| return 0; |
| } |
| } |
| |
| if (cst) { |
| *cst = i & V_ASN1_CONSTRUCTED; |
| } |
| |
| if (olen) { |
| *olen = plen; |
| } |
| |
| if (oclass) { |
| *oclass = pclass; |
| } |
| |
| if (otag) { |
| *otag = ptag; |
| } |
| |
| *in = p; |
| return 1; |
| } |
