diff options
Diffstat (limited to 'src/pluto/pkcs7.c')
| -rw-r--r-- | src/pluto/pkcs7.c | 755 |
1 files changed, 0 insertions, 755 deletions
diff --git a/src/pluto/pkcs7.c b/src/pluto/pkcs7.c deleted file mode 100644 index 10b2a4d5a..000000000 --- a/src/pluto/pkcs7.c +++ /dev/null @@ -1,755 +0,0 @@ -/* Support of PKCS#7 data structures - * Copyright (C) 2005 Jan Hutter, Martin Willi - * Copyright (C) 2002-2009 Andreas Steffen - * - * HSR 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. - */ - -#include <stdlib.h> -#include <string.h> -#include <time.h> - -#include <library.h> -#include <debug.h> -#include <asn1/asn1.h> -#include <asn1/asn1_parser.h> -#include <asn1/oid.h> -#include <crypto/rngs/rng.h> -#include <crypto/crypters/crypter.h> -#include <credentials/certificates/x509.h> - -#include "pkcs7.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 */ - { 0, "exit", ASN1_EOC, ASN1_EXIT } -}; -#define PKCS7_INFO_TYPE 1 -#define PKCS7_INFO_CONTENT 2 - -/** - * 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 */ - { 0, "exit", ASN1_EOC, ASN1_EXIT } -}; -#define PKCS7_SIGNED_VERSION 1 -#define PKCS7_DIGEST_ALG 3 -#define PKCS7_SIGNED_CONTENT_INFO 5 -#define PKCS7_SIGNED_CERT 7 -#define PKCS7_SIGNER_INFO 13 -#define PKCS7_SIGNER_INFO_VERSION 14 -#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 - -/** - * 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 */ - { 0, "exit", ASN1_EOC, ASN1_EXIT } -}; -#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 - -/** - * Parse PKCS#7 ContentInfo object - */ -bool pkcs7_parse_contentInfo(chunk_t blob, u_int level0, contentInfo_t *cInfo) -{ - asn1_parser_t *parser; - chunk_t object; - int objectID; - bool success = FALSE; - - parser = asn1_parser_create(contentInfoObjects, blob); - parser->set_top_level(parser, level0); - - while (parser->iterate(parser, &objectID, &object)) - { - if (objectID == PKCS7_INFO_TYPE) - { - cInfo->type = asn1_known_oid(object); - if (cInfo->type < OID_PKCS7_DATA - || cInfo->type > OID_PKCS7_ENCRYPTED_DATA) - { - DBG1(DBG_LIB, "unknown pkcs7 content type"); - goto end; - } - } - else if (objectID == PKCS7_INFO_CONTENT) - { - cInfo->content = object; - } - } - success = parser->success(parser); - -end: - parser->destroy(parser); - return success; -} - -/** - * Parse a PKCS#7 signedData object - */ -bool pkcs7_parse_signedData(chunk_t blob, contentInfo_t *data, - linked_list_t *certs, - chunk_t *attributes, certificate_t *cacert) -{ - asn1_parser_t *parser; - chunk_t object; - int digest_alg = OID_UNKNOWN; - int enc_alg = OID_UNKNOWN; - int signerInfos = 0; - int version; - int objectID; - bool success = FALSE; - - contentInfo_t cInfo = empty_contentInfo; - chunk_t encrypted_digest = chunk_empty; - - if (!pkcs7_parse_contentInfo(blob, 0, &cInfo)) - { - return FALSE; - } - if (cInfo.type != OID_PKCS7_SIGNED_DATA) - { - DBG1(DBG_LIB, "pkcs7 content type is not signedData"); - return FALSE; - } - - parser = asn1_parser_create(signedDataObjects, cInfo.content); - parser->set_top_level(parser, 2); - - while (parser->iterate(parser, &objectID, &object)) - { - u_int level = parser->get_level(parser); - - switch (objectID) - { - case PKCS7_SIGNED_VERSION: - version = object.len ? (int)*object.ptr : 0; - DBG2(DBG_LIB, " v%d", version); - break; - case PKCS7_DIGEST_ALG: - digest_alg = asn1_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: - { - certificate_t *cert; - - DBG2(DBG_LIB, " parsing pkcs7-wrapped certificate"); - cert = lib->creds->create(lib->creds, - CRED_CERTIFICATE, CERT_X509, - BUILD_BLOB_ASN1_DER, object, - BUILD_END); - if (cert) - { - certs->insert_last(certs, cert); - } - } - break; - case PKCS7_SIGNER_INFO: - signerInfos++; - DBG2(DBG_LIB, " signer #%d", signerInfos); - break; - case PKCS7_SIGNER_INFO_VERSION: - version = object.len ? (int)*object.ptr : 0; - DBG2(DBG_LIB, " v%d", version); - break; - case PKCS7_SIGNED_ISSUER: - { - identification_t *issuer = identification_create_from_encoding( - ID_DER_ASN1_DN, object); - DBG2(DBG_LIB, " \"%Y\"", issuer); - issuer->destroy(issuer); - break; - } - case PKCS7_AUTH_ATTRIBUTES: - if (attributes != NULL) - { - *attributes = object; - *attributes->ptr = ASN1_SET; - } - break; - case PKCS7_DIGEST_ALGORITHM: - digest_alg = asn1_parse_algorithmIdentifier(object, level, NULL); - break; - case PKCS7_DIGEST_ENC_ALGORITHM: - enc_alg = asn1_parse_algorithmIdentifier(object, level, NULL); - break; - case PKCS7_ENCRYPTED_DIGEST: - encrypted_digest = object; - } - } - success = parser->success(parser); - parser->destroy(parser); - if (!success) - { - return FALSE; - } - - /* check the signature only if a cacert is available */ - if (cacert != NULL) - { - public_key_t *key; - signature_scheme_t scheme; - - scheme = signature_scheme_from_oid(digest_alg); - if (scheme == SIGN_UNKNOWN) - { - DBG1(DBG_LIB, "unsupported signature scheme"); - return FALSE; - } - if (signerInfos == 0) - { - DBG1(DBG_LIB, "no signerInfo object found"); - return FALSE; - } - else if (signerInfos > 1) - { - DBG1(DBG_LIB, "more than one signerInfo object found"); - return FALSE; - } - if (attributes->ptr == NULL) - { - DBG1(DBG_LIB, "no authenticatedAttributes object found"); - return FALSE; - } - if (enc_alg != OID_RSA_ENCRYPTION) - { - DBG1(DBG_LIB, "only RSA digest encryption supported"); - return FALSE; - } - - /* verify the signature */ - key = cacert->get_public_key(cacert); - if (key == NULL) - { - DBG1(DBG_LIB, "no public key found in CA certificate"); - return FALSE; - } - if (key->verify(key, scheme, *attributes, encrypted_digest)) - { - DBG2(DBG_LIB, "signature is valid"); - } - else - { - DBG1(DBG_LIB, "invalid signature"); - success = FALSE; - } - key->destroy(key); - } - return success; -} - -/** - * Parse a PKCS#7 envelopedData object - */ -bool pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data, - chunk_t serialNumber, - private_key_t *key) -{ - asn1_parser_t *parser; - chunk_t object; - chunk_t iv = chunk_empty; - chunk_t symmetric_key = chunk_empty; - chunk_t encrypted_content = chunk_empty; - - crypter_t *crypter = NULL; - - int enc_alg = OID_UNKNOWN; - int content_enc_alg = OID_UNKNOWN; - int version; - int objectID; - bool success = FALSE; - - contentInfo_t cInfo = empty_contentInfo; - *data = chunk_empty; - - if (!pkcs7_parse_contentInfo(blob, 0, &cInfo)) - { - goto failed; - } - if (cInfo.type != OID_PKCS7_ENVELOPED_DATA) - { - DBG1(DBG_LIB, "pkcs7 content type is not envelopedData"); - goto failed; - } - - parser = asn1_parser_create(envelopedDataObjects, cInfo.content); - parser->set_top_level(parser, 2); - - while (parser->iterate(parser, &objectID, &object)) - { - u_int level = parser->get_level(parser); - - switch (objectID) - { - case PKCS7_ENVELOPED_VERSION: - version = object.len ? (int)*object.ptr : 0; - DBG2(DBG_LIB, " v%d", version); - if (version != 0) - { - DBG1(DBG_LIB, "envelopedData version is not 0"); - goto end; - } - break; - case PKCS7_RECIPIENT_INFO_VERSION: - version = object.len ? (int)*object.ptr : 0; - DBG2(DBG_LIB, " v%d", version); - if (version != 0) - { - DBG1(DBG_LIB, "recipient info version is not 0"); - goto end; - } - break; - case PKCS7_ISSUER: - { - identification_t *issuer = identification_create_from_encoding( - ID_DER_ASN1_DN, object); - DBG2(DBG_LIB, " \"%Y\"", issuer); - issuer->destroy(issuer); - break; - } - case PKCS7_SERIAL_NUMBER: - if (!chunk_equals(serialNumber, object)) - { - DBG1(DBG_LIB, "serial numbers do not match"); - goto end; - } - break; - case PKCS7_ENCRYPTION_ALG: - enc_alg = asn1_parse_algorithmIdentifier(object, level, NULL); - if (enc_alg != OID_RSA_ENCRYPTION) - { - DBG1(DBG_LIB, "only rsa encryption supported"); - goto end; - } - break; - case PKCS7_ENCRYPTED_KEY: - if (!key->decrypt(key, ENCRYPT_RSA_PKCS1, object, &symmetric_key)) - { - DBG1(DBG_LIB, "symmetric key could not be decrypted with rsa"); - goto end; - } - DBG4(DBG_LIB, "symmetric key %B", &symmetric_key); - break; - case PKCS7_CONTENT_TYPE: - if (asn1_known_oid(object) != OID_PKCS7_DATA) - { - DBG1(DBG_LIB, "encrypted content not of type pkcs7 data"); - goto end; - } - break; - case PKCS7_CONTENT_ENC_ALGORITHM: - content_enc_alg = asn1_parse_algorithmIdentifier(object, level, &iv); - - if (content_enc_alg == OID_UNKNOWN) - { - DBG1(DBG_LIB, "unknown content encryption algorithm"); - goto end; - } - if (!asn1_parse_simple_object(&iv, ASN1_OCTET_STRING, level+1, "IV")) - { - DBG1(DBG_LIB, "IV could not be parsed"); - goto end; - } - break; - case PKCS7_ENCRYPTED_CONTENT: - encrypted_content = object; - break; - } - } - success = parser->success(parser); - -end: - parser->destroy(parser); - if (!success) - { - goto failed; - } - success = FALSE; - - /* decrypt the content */ - { - encryption_algorithm_t alg; - size_t key_size; - crypter_t *crypter; - - alg = encryption_algorithm_from_oid(content_enc_alg, &key_size); - if (alg == ENCR_UNDEFINED) - { - DBG1(DBG_LIB, "unsupported content encryption algorithm"); - goto failed; - } - crypter = lib->crypto->create_crypter(lib->crypto, alg, key_size); - if (crypter == NULL) - { - DBG1(DBG_LIB, "crypter %N not available", encryption_algorithm_names, alg); - goto failed; - } - if (symmetric_key.len != crypter->get_key_size(crypter)) - { - DBG1(DBG_LIB, "symmetric key length %d is wrong", symmetric_key.len); - goto failed; - } - if (iv.len != crypter->get_iv_size(crypter)) - { - DBG1(DBG_LIB, "IV length %d is wrong", iv.len); - goto failed; - } - crypter->set_key(crypter, symmetric_key); - crypter->decrypt(crypter, encrypted_content, iv, data); - DBG4(DBG_LIB, "decrypted content with padding: %B", data); - } - - /* remove the padding */ - { - u_char *pos = data->ptr + data->len - 1; - u_char pattern = *pos; - size_t padding = pattern; - - if (padding > data->len) - { - DBG1(DBG_LIB, "padding greater than data length"); - goto failed; - } - data->len -= padding; - - while (padding-- > 0) - { - if (*pos-- != pattern) - { - DBG1(DBG_LIB, "wrong padding pattern"); - goto failed; - } - } - } - success = TRUE; - -failed: - DESTROY_IF(crypter); - chunk_clear(&symmetric_key); - if (!success) - { - free(data->ptr); - } - return success; -} - -/** - * @brief Builds a contentType attribute - * - * @return ASN.1 encoded contentType attribute - */ -chunk_t pkcs7_contentType_attribute(void) -{ - return asn1_wrap(ASN1_SEQUENCE, "mm", - asn1_build_known_oid(OID_PKCS9_CONTENT_TYPE), - asn1_wrap(ASN1_SET, "m", - asn1_build_known_oid(OID_PKCS7_DATA))); -} - -/** - * @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) -{ - chunk_t digest; - hash_algorithm_t hash_alg; - hasher_t *hasher; - - hash_alg = hasher_algorithm_from_oid(digest_alg); - hasher = lib->crypto->create_hasher(lib->crypto, hash_alg); - hasher->allocate_hash(hasher, content, &digest); - hasher->destroy(hasher); - - return asn1_wrap(ASN1_SEQUENCE, "mm", - asn1_build_known_oid(OID_PKCS9_MESSAGE_DIGEST), - asn1_wrap(ASN1_SET, "m", - asn1_wrap(ASN1_OCTET_STRING, "m", digest))); -} - -/** - * build a DER-encoded contentInfo object - */ -static chunk_t pkcs7_build_contentInfo(contentInfo_t *cInfo) -{ - return (cInfo->content.ptr) ? - asn1_wrap(ASN1_SEQUENCE, "mm", - asn1_build_known_oid(cInfo->type), - asn1_simple_object(ASN1_CONTEXT_C_0, cInfo->content)) : - asn1_build_known_oid(cInfo->type); -} - -/** - * build issuerAndSerialNumber object - */ -chunk_t pkcs7_build_issuerAndSerialNumber(certificate_t *cert) -{ - identification_t *issuer = cert->get_issuer(cert); - x509_t *x509 = (x509_t*)cert; - - return asn1_wrap(ASN1_SEQUENCE, "cm", - issuer->get_encoding(issuer), - asn1_integer("c", x509->get_serial(x509))); -} - -/** - * create a signed pkcs7 contentInfo object - */ -chunk_t pkcs7_build_signedData(chunk_t data, chunk_t attributes, - certificate_t *cert, int digest_alg, - private_key_t *key) -{ - contentInfo_t pkcs7Data, signedData; - chunk_t authenticatedAttributes = chunk_empty; - chunk_t encryptedDigest = chunk_empty; - chunk_t signerInfo, cInfo, signature, encoding = chunk_empty;; - signature_scheme_t scheme = signature_scheme_from_oid(digest_alg); - - if (attributes.ptr) - { - if (key->sign(key, scheme, attributes, &signature)) - { - encryptedDigest = asn1_wrap(ASN1_OCTET_STRING, "m", signature); - authenticatedAttributes = chunk_clone(attributes); - *authenticatedAttributes.ptr = ASN1_CONTEXT_C_0; - } - } - else if (data.ptr) - { - if (key->sign(key, scheme, data, &signature)) - { - encryptedDigest = asn1_wrap(ASN1_OCTET_STRING, "m", signature); - } - } - signerInfo = asn1_wrap(ASN1_SEQUENCE, "cmmmmm" - , ASN1_INTEGER_1 - , pkcs7_build_issuerAndSerialNumber(cert) - , asn1_algorithmIdentifier(digest_alg) - , authenticatedAttributes - , asn1_algorithmIdentifier(OID_RSA_ENCRYPTION) - , encryptedDigest); - - pkcs7Data.type = OID_PKCS7_DATA; - pkcs7Data.content = (data.ptr == NULL)? chunk_empty - : asn1_simple_object(ASN1_OCTET_STRING, data); - - cert->get_encoding(cert, CERT_ASN1_DER, &encoding); - signedData.type = OID_PKCS7_SIGNED_DATA; - signedData.content = asn1_wrap(ASN1_SEQUENCE, "cmmmm" - , ASN1_INTEGER_1 - , asn1_wrap(ASN1_SET, "m", asn1_algorithmIdentifier(digest_alg)) - , pkcs7_build_contentInfo(&pkcs7Data) - , asn1_wrap(ASN1_CONTEXT_C_0, "m", encoding) - , asn1_wrap(ASN1_SET, "m", signerInfo)); - - cInfo = pkcs7_build_contentInfo(&signedData); - DBG3(DBG_LIB, "signedData %B", &cInfo); - - free(pkcs7Data.content.ptr); - free(signedData.content.ptr); - return cInfo; -} - -/** - * create a symmetrically encrypted pkcs7 contentInfo object - */ -chunk_t pkcs7_build_envelopedData(chunk_t data, certificate_t *cert, int enc_alg) -{ - encryption_algorithm_t alg; - size_t alg_key_size; - chunk_t symmetricKey, protectedKey, iv, in, out; - crypter_t *crypter; - - alg = encryption_algorithm_from_oid(enc_alg, &alg_key_size); - crypter = lib->crypto->create_crypter(lib->crypto, alg, - alg_key_size/BITS_PER_BYTE); - if (crypter == NULL) - { - DBG1(DBG_LIB, "crypter for %N not available", encryption_algorithm_names, alg); - return chunk_empty; - } - - /* generate a true random symmetric encryption key and a pseudo-random iv */ - { - rng_t *rng; - - rng = lib->crypto->create_rng(lib->crypto, RNG_TRUE); - rng->allocate_bytes(rng, crypter->get_key_size(crypter), &symmetricKey); - DBG4(DBG_LIB, "symmetric encryption key %B", &symmetricKey); - rng->destroy(rng); - - rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK); - rng->allocate_bytes(rng, crypter->get_iv_size(crypter), &iv); - DBG4(DBG_LIB, "initialization vector: %B", &iv); - rng->destroy(rng); - } - - /* pad the data to a multiple of the block size */ - { - size_t block_size = crypter->get_block_size(crypter); - size_t padding = block_size - data.len % block_size; - - in.len = data.len + padding; - in.ptr = malloc(in.len); - - DBG2(DBG_LIB, "padding %u bytes of data to multiple block size of %u bytes", - data.len, in.len); - - /* copy data */ - memcpy(in.ptr, data.ptr, data.len); - /* append padding */ - memset(in.ptr + data.len, padding, padding); - } - DBG3(DBG_LIB, "padded unencrypted data %B", &in); - - /* symmetric encryption of data object */ - crypter->set_key(crypter, symmetricKey); - crypter->encrypt(crypter, in, iv, &out); - crypter->destroy(crypter); - chunk_clear(&in); - DBG3(DBG_LIB, "encrypted data %B", &out); - - /* protect symmetric key by public key encryption */ - { - public_key_t *key = cert->get_public_key(cert); - - if (key == NULL) - { - DBG1(DBG_LIB, "public key not found in encryption certificate"); - chunk_clear(&symmetricKey); - chunk_free(&iv); - chunk_free(&out); - return chunk_empty; - } - key->encrypt(key, ENCRYPT_RSA_PKCS1, symmetricKey, &protectedKey); - key->destroy(key); - } - - /* build pkcs7 enveloped data object */ - { - - chunk_t contentEncryptionAlgorithm = asn1_wrap(ASN1_SEQUENCE, "mm" - , asn1_build_known_oid(enc_alg) - , asn1_simple_object(ASN1_OCTET_STRING, iv)); - - chunk_t encryptedContentInfo = asn1_wrap(ASN1_SEQUENCE, "mmm" - , asn1_build_known_oid(OID_PKCS7_DATA) - , contentEncryptionAlgorithm - , asn1_wrap(ASN1_CONTEXT_S_0, "m", out)); - - chunk_t encryptedKey = asn1_wrap(ASN1_OCTET_STRING, "m" - , protectedKey); - - chunk_t recipientInfo = asn1_wrap(ASN1_SEQUENCE, "cmmm" - , ASN1_INTEGER_0 - , pkcs7_build_issuerAndSerialNumber(cert) - , asn1_algorithmIdentifier(OID_RSA_ENCRYPTION) - , 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); - DBG3(DBG_LIB, "envelopedData %B", &cInfo); - - chunk_free(&envelopedData.content); - chunk_free(&iv); - chunk_clear(&symmetricKey); - return cInfo; - } -} |