diff options
Diffstat (limited to 'programs/pluto/pkcs7.c')
| -rw-r--r-- | programs/pluto/pkcs7.c | 862 |
1 files changed, 0 insertions, 862 deletions
diff --git a/programs/pluto/pkcs7.c b/programs/pluto/pkcs7.c deleted file mode 100644 index 0691a80d6..000000000 --- a/programs/pluto/pkcs7.c +++ /dev/null @@ -1,862 +0,0 @@ -/* Support of PKCS#7 data structures - * Copyright (C) 2005 Jan Hutter, Martin Willi - * Copyright (C) 2002-2005 Andreas Steffen - * Hochschule fuer Technik Rapperswil, Switzerland - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the - * Free Software Foundation; either version 2 of the License, or (at your - * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY - * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * for more details. - * - * RCSID $Id: pkcs7.c,v 1.13 2005/12/22 22:11:24 as Exp $ - */ - -#include <stdlib.h> -#include <string.h> -#include <crypto/des.h> - -#include <freeswan.h> - -#include "constants.h" -#include "defs.h" -#include "asn1.h" -#include "oid.h" -#include "log.h" -#include "x509.h" -#include "certs.h" -#include "pkcs7.h" -#include "rnd.h" - -const contentInfo_t empty_contentInfo = { - OID_UNKNOWN , /* type */ - { NULL, 0 } /* content */ -}; - -/* ASN.1 definition of the PKCS#7 ContentInfo type */ - -static const asn1Object_t contentInfoObjects[] = { - { 0, "contentInfo", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */ - { 1, "contentType", ASN1_OID, ASN1_BODY }, /* 1 */ - { 1, "content", ASN1_CONTEXT_C_0, ASN1_OPT | - ASN1_BODY }, /* 2 */ - { 1, "end opt", ASN1_EOC, ASN1_END } /* 3 */ -}; - -#define PKCS7_INFO_TYPE 1 -#define PKCS7_INFO_CONTENT 2 -#define PKCS7_INFO_ROOF 4 - -/* ASN.1 definition of the PKCS#7 signedData type */ - -static const asn1Object_t signedDataObjects[] = { - { 0, "signedData", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */ - { 1, "version", ASN1_INTEGER, ASN1_BODY }, /* 1 */ - { 1, "digestAlgorithms", ASN1_SET, ASN1_LOOP }, /* 2 */ - { 2, "algorithm", ASN1_EOC, ASN1_RAW }, /* 3 */ - { 1, "end loop", ASN1_EOC, ASN1_END }, /* 4 */ - { 1, "contentInfo", ASN1_EOC, ASN1_RAW }, /* 5 */ - { 1, "certificates", ASN1_CONTEXT_C_0, ASN1_OPT | - ASN1_LOOP }, /* 6 */ - { 2, "certificate", ASN1_SEQUENCE, ASN1_OBJ }, /* 7 */ - { 1, "end opt or loop", ASN1_EOC, ASN1_END }, /* 8 */ - { 1, "crls", ASN1_CONTEXT_C_1, ASN1_OPT | - ASN1_LOOP }, /* 9 */ - { 2, "crl", ASN1_SEQUENCE, ASN1_OBJ }, /* 10 */ - { 1, "end opt or loop", ASN1_EOC, ASN1_END }, /* 11 */ - { 1, "signerInfos", ASN1_SET, ASN1_LOOP }, /* 12 */ - { 2, "signerInfo", ASN1_SEQUENCE, ASN1_NONE }, /* 13 */ - { 3, "version", ASN1_INTEGER, ASN1_BODY }, /* 14 */ - { 3, "issuerAndSerialNumber", ASN1_SEQUENCE, ASN1_BODY }, /* 15 */ - { 4, "issuer", ASN1_SEQUENCE, ASN1_OBJ }, /* 16 */ - { 4, "serial", ASN1_INTEGER, ASN1_BODY }, /* 17 */ - { 3, "digestAlgorithm", ASN1_EOC, ASN1_RAW }, /* 18 */ - { 3, "authenticatedAttributes", ASN1_CONTEXT_C_0, ASN1_OPT | - ASN1_OBJ }, /* 19 */ - { 3, "end opt", ASN1_EOC, ASN1_END }, /* 20 */ - { 3, "digestEncryptionAlgorithm", ASN1_EOC, ASN1_RAW }, /* 21 */ - { 3, "encryptedDigest", ASN1_OCTET_STRING, ASN1_BODY }, /* 22 */ - { 3, "unauthenticatedAttributes", ASN1_CONTEXT_C_1, ASN1_OPT }, /* 23 */ - { 3, "end opt", ASN1_EOC, ASN1_END }, /* 24 */ - { 1, "end loop", ASN1_EOC, ASN1_END } /* 25 */ -}; - -#define PKCS7_DIGEST_ALG 3 -#define PKCS7_SIGNED_CONTENT_INFO 5 -#define PKCS7_SIGNED_CERT 7 -#define PKCS7_SIGNER_INFO 13 -#define PKCS7_SIGNED_ISSUER 16 -#define PKCS7_SIGNED_SERIAL_NUMBER 17 -#define PKCS7_DIGEST_ALGORITHM 18 -#define PKCS7_AUTH_ATTRIBUTES 19 -#define PKCS7_DIGEST_ENC_ALGORITHM 21 -#define PKCS7_ENCRYPTED_DIGEST 22 -#define PKCS7_SIGNED_ROOF 26 - -/* ASN.1 definition of the PKCS#7 envelopedData type */ - -static const asn1Object_t envelopedDataObjects[] = { - { 0, "envelopedData", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */ - { 1, "version", ASN1_INTEGER, ASN1_BODY }, /* 1 */ - { 1, "recipientInfos", ASN1_SET, ASN1_LOOP }, /* 2 */ - { 2, "recipientInfo", ASN1_SEQUENCE, ASN1_BODY }, /* 3 */ - { 3, "version", ASN1_INTEGER, ASN1_BODY }, /* 4 */ - { 3, "issuerAndSerialNumber", ASN1_SEQUENCE, ASN1_BODY }, /* 5 */ - { 4, "issuer", ASN1_SEQUENCE, ASN1_OBJ }, /* 6 */ - { 4, "serial", ASN1_INTEGER, ASN1_BODY }, /* 7 */ - { 3, "encryptionAlgorithm", ASN1_EOC, ASN1_RAW }, /* 8 */ - { 3, "encryptedKey", ASN1_OCTET_STRING, ASN1_BODY }, /* 9 */ - { 1, "end loop", ASN1_EOC, ASN1_END }, /* 10 */ - { 1, "encryptedContentInfo", ASN1_SEQUENCE, ASN1_OBJ }, /* 11 */ - { 2, "contentType", ASN1_OID, ASN1_BODY }, /* 12 */ - { 2, "contentEncryptionAlgorithm", ASN1_EOC, ASN1_RAW }, /* 13 */ - { 2, "encryptedContent", ASN1_CONTEXT_S_0, ASN1_BODY } /* 14 */ -}; - -#define PKCS7_ENVELOPED_VERSION 1 -#define PKCS7_RECIPIENT_INFO_VERSION 4 -#define PKCS7_ISSUER 6 -#define PKCS7_SERIAL_NUMBER 7 -#define PKCS7_ENCRYPTION_ALG 8 -#define PKCS7_ENCRYPTED_KEY 9 -#define PKCS7_CONTENT_TYPE 12 -#define PKCS7_CONTENT_ENC_ALGORITHM 13 -#define PKCS7_ENCRYPTED_CONTENT 14 -#define PKCS7_ENVELOPED_ROOF 15 - -/* PKCS7 contentInfo OIDs */ - -static u_char ASN1_pkcs7_data_oid_str[] = { - 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x07, 0x01 -}; - -static u_char ASN1_pkcs7_signed_data_oid_str[] = { - 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x07, 0x02 -}; - -static u_char ASN1_pkcs7_enveloped_data_oid_str[] = { - 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x07, 0x03 -}; - -static u_char ASN1_pkcs7_signed_enveloped_data_oid_str[] = { - 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x07, 0x04 -}; - -static u_char ASN1_pkcs7_digested_data_oid_str[] = { - 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x07, 0x05 -}; - -static char ASN1_pkcs7_encrypted_data_oid_str[] = { - 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x07, 0x06 -}; - -static const chunk_t ASN1_pkcs7_data_oid = - strchunk(ASN1_pkcs7_data_oid_str); -static const chunk_t ASN1_pkcs7_signed_data_oid = - strchunk(ASN1_pkcs7_signed_data_oid_str); -static const chunk_t ASN1_pkcs7_enveloped_data_oid = - strchunk(ASN1_pkcs7_enveloped_data_oid_str); -static const chunk_t ASN1_pkcs7_signed_enveloped_data_oid = - strchunk(ASN1_pkcs7_signed_enveloped_data_oid_str); -static const chunk_t ASN1_pkcs7_digested_data_oid = - strchunk(ASN1_pkcs7_digested_data_oid_str); -static const chunk_t ASN1_pkcs7_encrypted_data_oid = - strchunk(ASN1_pkcs7_encrypted_data_oid_str); - -/* 3DES and DES encryption OIDs */ - -static u_char ASN1_3des_ede_cbc_oid_str[] = { - 0x06, 0x08, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x03, 0x07 -}; - -static u_char ASN1_des_cbc_oid_str[] = { - 0x06, 0x05, 0x2B, 0x0E, 0x03, 0x02, 0x07 -}; - -static const chunk_t ASN1_3des_ede_cbc_oid = - strchunk(ASN1_3des_ede_cbc_oid_str); -static const chunk_t ASN1_des_cbc_oid = - strchunk(ASN1_des_cbc_oid_str); - -/* PKCS#7 attribute type OIDs */ - -static u_char ASN1_contentType_oid_str[] = { - 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x09, 0x03 -}; - -static u_char ASN1_messageDigest_oid_str[] = { - 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x09, 0x04 -}; - -static const chunk_t ASN1_contentType_oid = - strchunk(ASN1_contentType_oid_str); -static const chunk_t ASN1_messageDigest_oid = - strchunk(ASN1_messageDigest_oid_str); - -/* - * Parse PKCS#7 ContentInfo object - */ -bool -pkcs7_parse_contentInfo(chunk_t blob, u_int level0, contentInfo_t *cInfo) -{ - asn1_ctx_t ctx; - chunk_t object; - u_int level; - int objectID = 0; - - asn1_init(&ctx, blob, level0, FALSE, DBG_RAW); - - while (objectID < PKCS7_INFO_ROOF) - { - if (!extract_object(contentInfoObjects, &objectID, &object, &level, &ctx)) - return FALSE; - - if (objectID == PKCS7_INFO_TYPE) - { - cInfo->type = known_oid(object); - if (cInfo->type < OID_PKCS7_DATA - || cInfo->type > OID_PKCS7_ENCRYPTED_DATA) - { - plog("unknown pkcs7 content type"); - return FALSE; - } - } - else if (objectID == PKCS7_INFO_CONTENT) - { - cInfo->content = object; - } - objectID++; - } - return TRUE; -} - -/* - * Parse a PKCS#7 signedData object - */ -bool -pkcs7_parse_signedData(chunk_t blob, contentInfo_t *data, x509cert_t **cert -, chunk_t *attributes, const x509cert_t *cacert) -{ - u_char buf[BUF_LEN]; - asn1_ctx_t ctx; - chunk_t object; - u_int level; - int digest_alg = OID_UNKNOWN; - int enc_alg = OID_UNKNOWN; - int signerInfos = 0; - int objectID = 0; - - contentInfo_t cInfo = empty_contentInfo; - chunk_t encrypted_digest = empty_chunk; - - if (!pkcs7_parse_contentInfo(blob, 0, &cInfo)) - return FALSE; - - if (cInfo.type != OID_PKCS7_SIGNED_DATA) - { - plog("pkcs7 content type is not signedData"); - return FALSE; - } - - asn1_init(&ctx, cInfo.content, 2, FALSE, DBG_RAW); - - while (objectID < PKCS7_SIGNED_ROOF) - { - if (!extract_object(signedDataObjects, &objectID, &object, &level, &ctx)) - return FALSE; - - switch (objectID) - { - case PKCS7_DIGEST_ALG: - digest_alg = parse_algorithmIdentifier(object, level, NULL); - break; - case PKCS7_SIGNED_CONTENT_INFO: - if (data != NULL) - { - pkcs7_parse_contentInfo(object, level, data); - } - break; - case PKCS7_SIGNED_CERT: - if (cert != NULL) - { - chunk_t cert_blob; - - x509cert_t *newcert = alloc_thing(x509cert_t - , "pkcs7 wrapped x509cert"); - - clonetochunk(cert_blob, object.ptr, object.len - , "pkcs7 cert blob"); - *newcert = empty_x509cert; - - DBG(DBG_CONTROL | DBG_PARSING, - DBG_log("parsing pkcs7-wrapped certificate") - ) - if (parse_x509cert(cert_blob, level+1, newcert)) - { - newcert->next = *cert; - *cert = newcert; - } - else - { - free_x509cert(newcert); - } - } - break; - case PKCS7_SIGNER_INFO: - signerInfos++; - DBG(DBG_PARSING, - DBG_log(" signer #%d", signerInfos) - ) - break; - case PKCS7_SIGNED_ISSUER: - DBG(DBG_PARSING, - dntoa(buf, BUF_LEN, object); - DBG_log(" '%s'",buf) - ) - break; - case PKCS7_AUTH_ATTRIBUTES: - if (attributes != NULL) - { - *attributes = object; - *attributes->ptr = ASN1_SET; - } - break; - case PKCS7_DIGEST_ALGORITHM: - digest_alg = parse_algorithmIdentifier(object, level, NULL); - break; - case PKCS7_DIGEST_ENC_ALGORITHM: - enc_alg = parse_algorithmIdentifier(object, level, NULL); - break; - case PKCS7_ENCRYPTED_DIGEST: - encrypted_digest = object; - } - objectID++; - } - - /* check the signature only if a cacert is available */ - if (cacert != NULL) - { - if (signerInfos == 0) - { - plog("no signerInfo object found"); - return FALSE; - } - else if (signerInfos > 1) - { - plog("more than one signerInfo object found"); - return FALSE; - } - if (attributes->ptr == NULL) - { - plog("no authenticatedAttributes object found"); - return FALSE; - } - if (!check_signature(*attributes, encrypted_digest, digest_alg - , enc_alg, cacert)) - { - plog("invalid signature"); - return FALSE; - } - else - { - DBG(DBG_CONTROL, - DBG_log("signature is valid") - ) - } - } - return TRUE; -} - -/* - * Parse a PKCS#7 envelopedData object - */ -bool -pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data -, chunk_t serialNumber, const RSA_private_key_t *key) -{ - asn1_ctx_t ctx; - chunk_t object; - chunk_t iv = empty_chunk; - chunk_t symmetric_key = empty_chunk; - chunk_t encrypted_content = empty_chunk; - - u_char buf[BUF_LEN]; - u_int level; - u_int total_keys = 3; - int enc_alg = OID_UNKNOWN; - int content_enc_alg = OID_UNKNOWN; - int objectID = 0; - - contentInfo_t cInfo = empty_contentInfo; - *data = empty_chunk; - - if (!pkcs7_parse_contentInfo(blob, 0, &cInfo)) - goto failed; - - if (cInfo.type != OID_PKCS7_ENVELOPED_DATA) - { - plog("pkcs7 content type is not envelopedData"); - return FALSE; - } - - asn1_init(&ctx, cInfo.content, 2, FALSE, DBG_RAW); - - while (objectID < PKCS7_ENVELOPED_ROOF) - { - if (!extract_object(envelopedDataObjects, &objectID, &object, &level, &ctx)) - goto failed; - - switch (objectID) - { - case PKCS7_ENVELOPED_VERSION: - if (*object.ptr != 0) - { - plog("envelopedData version is not 0"); - goto failed; - } - break; - case PKCS7_RECIPIENT_INFO_VERSION: - if (*object.ptr != 0) - { - plog("recipient info version is not 0"); - goto failed; - } - break; - case PKCS7_ISSUER: - DBG(DBG_PARSING, - dntoa(buf, BUF_LEN, object); - DBG_log(" '%s'", buf) - ) - break; - case PKCS7_SERIAL_NUMBER: - if (!same_chunk(serialNumber, object)) - { - plog("serial numbers do not match"); - goto failed; - } - break; - case PKCS7_ENCRYPTION_ALG: - enc_alg = parse_algorithmIdentifier(object, level, NULL); - if (enc_alg != OID_RSA_ENCRYPTION) - { - plog("only rsa encryption supported"); - goto failed; - } - break; - case PKCS7_ENCRYPTED_KEY: - if (!RSA_decrypt(key, object, &symmetric_key)) - { - plog("symmetric key could not be decrypted with rsa"); - goto failed; - } - DBG(DBG_PRIVATE, - DBG_dump_chunk("symmetric key :", symmetric_key) - ) - break; - case PKCS7_CONTENT_TYPE: - if (known_oid(object) != OID_PKCS7_DATA) - { - plog("encrypted content not of type pkcs7 data"); - goto failed; - } - break; - case PKCS7_CONTENT_ENC_ALGORITHM: - content_enc_alg = parse_algorithmIdentifier(object, level, &iv); - - switch (content_enc_alg) - { - case OID_DES_CBC: - total_keys = 1; - break; - case OID_3DES_EDE_CBC: - total_keys = 3; - break; - default: - plog("Only DES and 3DES supported for symmetric encryption"); - goto failed; - } - if (symmetric_key.len != (total_keys * DES_CBC_BLOCK_SIZE)) - { - plog("key length is not %d",(total_keys * DES_CBC_BLOCK_SIZE)); - goto failed; - } - if (!parse_asn1_simple_object(&iv, ASN1_OCTET_STRING, level+1, "IV")) - { - plog("IV could not be parsed"); - goto failed; - } - if (iv.len != DES_CBC_BLOCK_SIZE) - { - plog("IV has wrong length"); - goto failed; - } - break; - case PKCS7_ENCRYPTED_CONTENT: - encrypted_content = object; - break; - } - objectID++; - } - - /* decrypt the content */ - { - u_int i; - des_cblock des_key[3], des_iv; - des_key_schedule key_s[3]; - - memcpy((char *)des_key, symmetric_key.ptr, symmetric_key.len); - memcpy((char *)des_iv, iv.ptr, iv.len); - - for (i = 0; i < total_keys; i++) - { - if (des_set_key(&des_key[i], key_s[i])) - { - plog("des key schedule failed"); - goto failed; - } - } - - data->len = encrypted_content.len; - data->ptr = alloc_bytes(data->len, "decrypted data"); - - switch (content_enc_alg) - { - case OID_DES_CBC: - des_cbc_encrypt((des_cblock*)encrypted_content.ptr - , (des_cblock*)data->ptr, data->len - , key_s[0], &des_iv, DES_DECRYPT); - break; - case OID_3DES_EDE_CBC: - des_ede3_cbc_encrypt( (des_cblock*)encrypted_content.ptr - , (des_cblock*)data->ptr, data->len - , key_s[0], key_s[1], key_s[2] - , &des_iv, DES_DECRYPT); - } - DBG(DBG_PRIVATE, - DBG_dump_chunk("decrypted content with padding:\n", *data) - ) - } - - /* remove the padding */ - { - u_char *pos = data->ptr + data->len - 1; - u_char pattern = *pos; - size_t padding = pattern; - - if (padding > data->len) - { - plog("padding greater than data length"); - goto failed; - } - data->len -= padding; - - while (padding-- > 0) - { - if (*pos-- != pattern) - { - plog("wrong padding pattern"); - goto failed; - } - } - } - freeanychunk(symmetric_key); - return TRUE; - -failed: - freeanychunk(symmetric_key); - pfreeany(data->ptr); - return FALSE; -} - -/** - * @brief Builds a contentType attribute - * - * @return ASN.1 encoded contentType attribute - */ -chunk_t -pkcs7_contentType_attribute(void) -{ - return asn1_wrap(ASN1_SEQUENCE, "cm" - , ASN1_contentType_oid - , asn1_simple_object(ASN1_SET, ASN1_pkcs7_data_oid)); -} - -/** - * @brief Builds a messageDigest attribute - * - * - * @param[in] blob content to create digest of - * @param[in] digest_alg digest algorithm to be used - * @return ASN.1 encoded messageDigest attribute - * - */ -chunk_t -pkcs7_messageDigest_attribute(chunk_t content, int digest_alg) -{ - u_char digest_buf[MAX_DIGEST_LEN]; - chunk_t digest = { digest_buf, MAX_DIGEST_LEN }; - - compute_digest(content, digest_alg, &digest); - - return asn1_wrap(ASN1_SEQUENCE, "cm" - , ASN1_messageDigest_oid - , asn1_wrap(ASN1_SET, "m" - , asn1_simple_object(ASN1_OCTET_STRING, digest) - ) - ); -} -/* - * build a DER-encoded contentInfo object - */ -static chunk_t -pkcs7_build_contentInfo(contentInfo_t *cInfo) -{ - chunk_t content_type; - - /* select DER-encoded OID for pkcs7 contentInfo type */ - switch(cInfo->type) - { - case OID_PKCS7_DATA: - content_type = ASN1_pkcs7_data_oid; - break; - case OID_PKCS7_SIGNED_DATA: - content_type = ASN1_pkcs7_signed_data_oid; - break; - case OID_PKCS7_ENVELOPED_DATA: - content_type = ASN1_pkcs7_enveloped_data_oid; - break; - case OID_PKCS7_SIGNED_ENVELOPED_DATA: - content_type = ASN1_pkcs7_signed_enveloped_data_oid; - break; - case OID_PKCS7_DIGESTED_DATA: - content_type = ASN1_pkcs7_digested_data_oid; - break; - case OID_PKCS7_ENCRYPTED_DATA: - content_type = ASN1_pkcs7_encrypted_data_oid; - break; - case OID_UNKNOWN: - default: - fprintf(stderr, "invalid pkcs7 contentInfo type"); - return empty_chunk; - } - - return (cInfo->content.ptr == NULL) - ? asn1_simple_object(ASN1_SEQUENCE, content_type) - : asn1_wrap(ASN1_SEQUENCE, "cm" - , content_type - , asn1_simple_object(ASN1_CONTEXT_C_0, cInfo->content) - ); -} - -/* - * build issuerAndSerialNumber object - */ -chunk_t -pkcs7_build_issuerAndSerialNumber(const x509cert_t *cert) -{ - return asn1_wrap(ASN1_SEQUENCE, "cm" - , cert->issuer - , asn1_simple_object(ASN1_INTEGER, cert->serialNumber)); -} - -/* - * create a signed pkcs7 contentInfo object - */ -chunk_t -pkcs7_build_signedData(chunk_t data, chunk_t attributes, const x509cert_t *cert -, int digest_alg, const RSA_private_key_t *key) -{ - contentInfo_t pkcs7Data, signedData; - chunk_t authenticatedAttributes, encryptedDigest, signerInfo, cInfo; - - chunk_t digestAlgorithm = asn1_algorithmIdentifier(digest_alg); - - if (attributes.ptr != NULL) - { - encryptedDigest = pkcs1_build_signature(attributes, digest_alg - , key, FALSE); - clonetochunk(authenticatedAttributes, attributes.ptr, attributes.len - , "authenticatedAttributes"); - *authenticatedAttributes.ptr = ASN1_CONTEXT_C_0; - } - else - { - encryptedDigest = (data.ptr == NULL)? empty_chunk - : pkcs1_build_signature(data, digest_alg, key, FALSE); - authenticatedAttributes = empty_chunk; - } - - signerInfo = asn1_wrap(ASN1_SEQUENCE, "cmcmcm" - , ASN1_INTEGER_1 - , pkcs7_build_issuerAndSerialNumber(cert) - , digestAlgorithm - , authenticatedAttributes - , ASN1_rsaEncryption_id - , encryptedDigest); - - pkcs7Data.type = OID_PKCS7_DATA; - pkcs7Data.content = (data.ptr == NULL)? empty_chunk - : asn1_simple_object(ASN1_OCTET_STRING, data); - - signedData.type = OID_PKCS7_SIGNED_DATA; - signedData.content = asn1_wrap(ASN1_SEQUENCE, "cmmmm" - , ASN1_INTEGER_1 - , asn1_simple_object(ASN1_SET, digestAlgorithm) - , pkcs7_build_contentInfo(&pkcs7Data) - , asn1_simple_object(ASN1_CONTEXT_C_0, cert->certificate) - , asn1_wrap(ASN1_SET, "m", signerInfo)); - - cInfo = pkcs7_build_contentInfo(&signedData); - DBG(DBG_RAW, - DBG_dump_chunk("signedData:\n", cInfo) - ) - - freeanychunk(pkcs7Data.content); - freeanychunk(signedData.content); - return cInfo; -} - -/* - * create a symmetrically encrypted pkcs7 contentInfo object - */ -chunk_t -pkcs7_build_envelopedData(chunk_t data, const x509cert_t *cert, int cipher) -{ - bool des_check_key_save; - des_key_schedule ks[3]; - des_cblock key[3], des_iv, des_iv_buf; - - chunk_t iv = { (u_char *)des_iv_buf, DES_CBC_BLOCK_SIZE }; - chunk_t out; - chunk_t cipher_oid; - - u_int total_keys, i; - size_t padding = pad_up(data.len, DES_CBC_BLOCK_SIZE); - - RSA_public_key_t public_key; - - init_RSA_public_key(&public_key, cert->publicExponent - , cert->modulus); - - if (padding == 0) - padding += DES_CBC_BLOCK_SIZE; - - out.len = data.len + padding; - out.ptr = alloc_bytes(out.len, "DES-encrypted output"); - - DBG(DBG_CONTROL, - DBG_log("padding %d bytes of data to multiple DES block size of %d bytes" - , (int)data.len, (int)out.len) - ) - - /* copy data */ - memcpy(out.ptr, data.ptr, data.len); - /* append padding */ - memset(out.ptr + data.len, padding, padding); - - DBG(DBG_RAW, - DBG_dump_chunk("Padded unencrypted data:\n", out) - ) - - /* select OID and keylength for specified cipher */ - switch (cipher) - { - case OID_DES_CBC: - total_keys = 1; - cipher_oid = ASN1_des_cbc_oid; - break; - case OID_3DES_EDE_CBC: - default: - total_keys = 3; - cipher_oid = ASN1_3des_ede_cbc_oid; - } - DBG(DBG_CONTROLMORE, - DBG_log("pkcs7 encryption cipher: %s", oid_names[cipher].name) - ) - - /* generate a strong random key for DES/3DES */ - des_check_key_save = des_check_key; - des_check_key = TRUE; - for (i = 0; i < total_keys;i++) - { - for (;;) - { - get_rnd_bytes((char*)key[i], DES_CBC_BLOCK_SIZE); - des_set_odd_parity(&key[i]); - if (!des_set_key(&key[i], ks[i])) - break; - plog("weak DES key discarded - we try again"); - } - DBG(DBG_PRIVATE, - DBG_dump("DES key:", key[i], 8) - ) - } - des_check_key = des_check_key_save; - - /* generate an iv for DES/3DES CBC */ - get_rnd_bytes(des_iv, DES_CBC_BLOCK_SIZE); - memcpy(iv.ptr, des_iv, DES_CBC_BLOCK_SIZE); - DBG(DBG_RAW, - DBG_dump_chunk("DES IV :", iv) - ) - - /* encryption using specified cipher */ - switch (cipher) - { - case OID_DES_CBC: - des_cbc_encrypt((des_cblock*)out.ptr, (des_cblock*)out.ptr, out.len - , ks[0], &des_iv, DES_ENCRYPT); - break; - case OID_3DES_EDE_CBC: - default: - des_ede3_cbc_encrypt((des_cblock*)out.ptr, (des_cblock*)out.ptr, out.len - , ks[0], ks[1], ks[2], &des_iv, DES_ENCRYPT); - } - DBG(DBG_RAW, - DBG_dump_chunk("Encrypted data:\n", out)); - - /* build pkcs7 enveloped data object */ - { - chunk_t contentEncryptionAlgorithm = asn1_wrap(ASN1_SEQUENCE, "cm" - , cipher_oid - , asn1_simple_object(ASN1_OCTET_STRING, iv)); - - chunk_t encryptedContentInfo = asn1_wrap(ASN1_SEQUENCE, "cmm" - , ASN1_pkcs7_data_oid - , contentEncryptionAlgorithm - , asn1_wrap(ASN1_CONTEXT_S_0, "m", out)); - - chunk_t plainKey = { (u_char *)key, DES_CBC_BLOCK_SIZE * total_keys }; - - chunk_t encryptedKey = asn1_wrap(ASN1_OCTET_STRING, "m" - , RSA_encrypt(&public_key, plainKey)); - - chunk_t recipientInfo = asn1_wrap(ASN1_SEQUENCE, "cmcm" - , ASN1_INTEGER_0 - , pkcs7_build_issuerAndSerialNumber(cert) - , ASN1_rsaEncryption_id - , encryptedKey); - - chunk_t cInfo; - contentInfo_t envelopedData; - - envelopedData.type = OID_PKCS7_ENVELOPED_DATA; - envelopedData.content = asn1_wrap(ASN1_SEQUENCE, "cmm" - , ASN1_INTEGER_0 - , asn1_wrap(ASN1_SET, "m", recipientInfo) - , encryptedContentInfo); - - cInfo = pkcs7_build_contentInfo(&envelopedData); - DBG(DBG_RAW, - DBG_dump_chunk("envelopedData:\n", cInfo) - ) - - free_RSA_public_content(&public_key); - freeanychunk(envelopedData.content); - return cInfo; - } -} |