denozord/strongswan-ext
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

completed pkcs7 parsing methods

Browse Source
This commit is contained in:
Andreas Steffen
2007-10-07 22:11:42 +00:00
parent 2d8a418059
commit 06ba2d36c3
2 changed files with 292 additions and 474 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/libstrongswan/crypto/pkcs7.c
+214 -434
View File
@@ -1,7 +1,7 @@
/** /**
* @file pkcs7.c * @file pkcs7.c
* *
* @brief Implementation of pkcs7_contentInfo_t. * @brief Implementation of pkcs7_t.
* *
*/ */
@@ -32,19 +32,22 @@
#include <asn1/asn1.h> #include <asn1/asn1.h>
#include <asn1/oid.h> #include <asn1/oid.h>
#include <crypto/x509.h> #include <crypto/x509.h>
#include <crypto/hashers/hasher.h>
#include <crypto/crypters/crypter.h>
#include <utils/linked_list.h>
#include "pkcs7.h" #include "pkcs7.h"
typedef struct private_pkcs7_contentInfo_t private_pkcs7_contentInfo_t; typedef struct private_pkcs7_t private_pkcs7_t;
/** /**
* Private data of a pkcs7_contentInfo_t object. * Private data of a pkcs7_t object.
*/ */
struct private_pkcs7_contentInfo_t { struct private_pkcs7_t {
/** /**
* Public interface for this certificate. * Public interface for this certificate.
*/ */
pkcs7_contentInfo_t public; pkcs7_t public;
/** /**
* contentInfo type * contentInfo type
@@ -55,6 +58,31 @@ struct private_pkcs7_contentInfo_t {
* ASN.1 encoded content * ASN.1 encoded content
*/ */
chunk_t content; chunk_t content;
/**
* Has the content already been parsed?
*/
bool parsed;
/**
* ASN.1 parsing start level
*/
u_int level;
/**
* retrieved data
*/
chunk_t data;
/**
* ASN.1 encoded attributes
*/
chunk_t attributes;
/**
* Linked list of X.509 certificates
*/
linked_list_t *certs;
}; };
/** /**
@@ -234,102 +262,93 @@ static const chunk_t ASN1_messageDigest_oid =
chunk_from_buf(ASN1_messageDigest_oid_str); chunk_from_buf(ASN1_messageDigest_oid_str);
/** /**
* Implements pkcs7_contentInfo_t.destroy * Implements pkcs7_t.is_signedData.
*/ */
static void destroy(private_pkcs7_contentInfo_t *this) static bool is_data(private_pkcs7_t *this)
{ {
free(this); return this->type == OID_PKCS7_DATA;
} }
/** /**
* Parse PKCS#7 ContentInfo object * Implements pkcs7_t.is_signedData.
*/ */
static bool pkcs7_parse_contentInfo(chunk_t blob, u_int level0, private_pkcs7_contentInfo_t *cInfo) static bool is_signedData(private_pkcs7_t *this)
{
return this->type == OID_PKCS7_SIGNED_DATA;
}
/**
* Implements pkcs7_t.is_signedData.
*/
static bool is_envelopedData(private_pkcs7_t *this)
{
return this->type == OID_PKCS7_ENVELOPED_DATA;
}
/**
* Check whether to abort the requested parsing
*/
static bool abort_parsing(private_pkcs7_t *this, int type)
{
if (this->type != type)
{
DBG1("pkcs7 content to be parsed is not of type '%s'",
oid_names[type]);
return TRUE;
}
if (this->parsed)
{
DBG1("pkcs7 content has already been parsed");
return TRUE;
}
this->parsed = TRUE;
return FALSE;
}
/**
* Implements pkcs7_t.parse_data.
*/
static bool parse_data(private_pkcs7_t *this)
{
chunk_t data = this->content;
if (abort_parsing(this, OID_PKCS7_DATA))
{
return FALSE;
}
if (parse_asn1_simple_object(&data, ASN1_OCTET_STRING, this->level, "data"))
{
this->data = chunk_clone(data);
return TRUE;
}
else
{
return FALSE;
}
}
/**
* Parse PKCS#7 signedData content
*/
static bool parse_signedData(private_pkcs7_t *this, x509_t *cacert)
{ {
asn1_ctx_t ctx; asn1_ctx_t ctx;
chunk_t object; chunk_t object;
u_int level; u_int level;
int objectID = 0; int objectID = 0;
asn1_init(&ctx, blob, level0, FALSE, FALSE);
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)
{
DBG1("unknown pkcs7 content type");
return FALSE;
}
}
else if (objectID == PKCS7_INFO_CONTENT)
{
cInfo->content = object;
}
objectID++;
}
return TRUE;
}
/*
* Described in header.
*/
pkcs7_contentInfo_t *pkcs7_contentInfo_create_from_chunk(chunk_t chunk, u_int level)
{
private_pkcs7_contentInfo_t *this = malloc_thing(private_pkcs7_contentInfo_t);
/* initialize */
this->type = OID_UNKNOWN;
this->content = chunk_empty;
/*public functions */
this->public.destroy = (void (*) (pkcs7_contentInfo_t*))destroy;
if (!pkcs7_parse_contentInfo(chunk, level, this))
{
destroy(this);
return NULL;
}
return &this->public;
}
/**
* Parse a PKCS#7 signedData object
*/
bool pkcs7_parse_signedData(chunk_t blob, pkcs7_contentInfo_t *data, x509_t **cert,
chunk_t *attributes, const x509_t *cacert)
{
u_char buf[BUF_LEN];
asn1_ctx_t ctx;
chunk_t object;
u_int level;
int digest_alg = OID_UNKNOWN; int digest_alg = OID_UNKNOWN;
int enc_alg = OID_UNKNOWN; int enc_alg = OID_UNKNOWN;
int signerInfos = 0; int signerInfos = 0;
int objectID = 0;
private_pkcs7_contentInfo_t cInfo;
chunk_t encrypted_digest = chunk_empty; chunk_t encrypted_digest = chunk_empty;
if (!pkcs7_parse_contentInfo(blob, 0, &cInfo)) if (abort_parsing(this, OID_PKCS7_SIGNED_DATA))
{ {
return FALSE; return FALSE;
} }
if (cInfo.type != OID_PKCS7_SIGNED_DATA)
{
DBG1("pkcs7 content type is not signedData");
return FALSE;
}
asn1_init(&ctx, cInfo.content, 2, FALSE, FALSE); asn1_init(&ctx, this->content, this->level, FALSE, FALSE);
while (objectID < PKCS7_SIGNED_ROOF) while (objectID < PKCS7_SIGNED_ROOF)
{ {
@@ -344,30 +363,15 @@ bool pkcs7_parse_signedData(chunk_t blob, pkcs7_contentInfo_t *data, x509_t **ce
digest_alg = parse_algorithmIdentifier(object, level, NULL); digest_alg = parse_algorithmIdentifier(object, level, NULL);
break; break;
case PKCS7_SIGNED_CONTENT_INFO: case PKCS7_SIGNED_CONTENT_INFO:
if (data != NULL) this->data = chunk_clone(object);
{
pkcs7_parse_contentInfo(object, level, data);
}
break; break;
case PKCS7_SIGNED_CERT: case PKCS7_SIGNED_CERT:
if (cert != NULL)
{ {
chunk_t cert_blob; x509_t *cert = x509_create_from_chunk(object, level+1);
x509_t *newcert = alloc_thing(x509_t, "pkcs7 wrapped x509cert"); if (cert)
clonetochunk(cert_blob, object.ptr, object.len, "pkcs7 cert blob");
*newcert = empty_x509cert;
DBG2("parsing pkcs7-wrapped certificate");
if (parse_x509cert(cert_blob, level+1, newcert))
{ {
newcert->next = *cert; this->certs->insert_last(this->certs, (void*)cert);
*cert = newcert;
}
else
{
newcert->destroy(newcert);
} }
} }
break; break;
@@ -385,11 +389,8 @@ bool pkcs7_parse_signedData(chunk_t blob, pkcs7_contentInfo_t *data, x509_t **ce
} }
break; break;
case PKCS7_AUTH_ATTRIBUTES: case PKCS7_AUTH_ATTRIBUTES:
if (attributes != NULL) this->attributes = object;
{ *this->attributes.ptr = ASN1_SET;
*attributes = object;
*attributes->ptr = ASN1_SET;
}
break; break;
case PKCS7_DIGEST_ALGORITHM: case PKCS7_DIGEST_ALGORITHM:
digest_alg = parse_algorithmIdentifier(object, level, NULL); digest_alg = parse_algorithmIdentifier(object, level, NULL);
@@ -406,6 +407,9 @@ bool pkcs7_parse_signedData(chunk_t blob, pkcs7_contentInfo_t *data, x509_t **ce
/* check the signature only if a cacert is available */ /* check the signature only if a cacert is available */
if (cacert != NULL) if (cacert != NULL)
{ {
rsa_public_key_t *signer = cacert->get_public_key(cacert);
hash_algorithm_t algorithm = hasher_algorithm_from_oid(digest_alg);
if (signerInfos == 0) if (signerInfos == 0)
{ {
DBG1("no signerInfo object found"); DBG1("no signerInfo object found");
@@ -416,59 +420,53 @@ bool pkcs7_parse_signedData(chunk_t blob, pkcs7_contentInfo_t *data, x509_t **ce
DBG1("more than one signerInfo object found"); DBG1("more than one signerInfo object found");
return FALSE; return FALSE;
} }
if (attributes->ptr == NULL) if (this->attributes.ptr == NULL)
{ {
DBG1("no authenticatedAttributes object found"); DBG1("no authenticatedAttributes object found");
return FALSE; return FALSE;
} }
if (!check_signature(*attributes, encrypted_digest, digest_alg if (enc_alg != OID_RSA_ENCRYPTION)
, enc_alg, cacert))
{ {
DBG1("invalid signature"); DBG1("only RSA digest encryption supported");
return FALSE;
}
if (signer->verify_emsa_pkcs1_signature(signer, algorithm,
this->attributes, encrypted_digest) != SUCCESS)
{
DBG1("invalid digest signature");
return FALSE; return FALSE;
} }
else else
{ {
DBG2("signature is valid"); DBG2("digest signature is valid");
} }
} }
return TRUE; return TRUE;
} }
/** /**
* Parse a PKCS#7 envelopedData object * Parse PKCS#7 envelopedData content
*/ */
bool pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data, static bool parse_envelopedData(private_pkcs7_t *this, chunk_t serialNumber,
chunk_t serialNumber, rsa_private_key_t *key)
const RSA_private_key_t *key)
{ {
asn1_ctx_t ctx; asn1_ctx_t ctx;
chunk_t object; 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 level;
u_int total_keys = 3;
int enc_alg = OID_UNKNOWN;
int content_enc_alg = OID_UNKNOWN;
int objectID = 0; int objectID = 0;
contentInfo_t cInfo = empty_contentInfo; chunk_t iv = chunk_empty;
*data = empty_chunk; chunk_t symmetric_key = chunk_empty;
chunk_t encrypted_content = chunk_empty;
if (!pkcs7_pkcs7_parse_contentInfo(blob, 0, &cInfo)) crypter_t *crypter = NULL;
if (abort_parsing(this, OID_PKCS7_ENVELOPED_DATA))
{ {
goto failed; return FALSE;
}
if (cInfo.type != OID_PKCS7_ENVELOPED_DATA)
{
DBG1("pkcs7 content type is not envelopedData");
goto failed;
} }
asn1_init(&ctx, cInfo.content, 2, FALSE, DBG_RAW); asn1_init(&ctx, this->content, this->level, FALSE, FALSE);
while (objectID < PKCS7_ENVELOPED_ROOF) while (objectID < PKCS7_ENVELOPED_ROOF)
{ {
@@ -510,15 +508,18 @@ bool pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data,
} }
break; break;
case PKCS7_ENCRYPTION_ALG: case PKCS7_ENCRYPTION_ALG:
enc_alg = parse_algorithmIdentifier(object, level, NULL); {
if (enc_alg != OID_RSA_ENCRYPTION) int alg = parse_algorithmIdentifier(object, level, NULL);
if (alg != OID_RSA_ENCRYPTION)
{ {
DBG1("only rsa encryption supported"); DBG1("only rsa encryption supported");
goto failed; goto failed;
} }
}
break; break;
case PKCS7_ENCRYPTED_KEY: case PKCS7_ENCRYPTED_KEY:
if (!RSA_decrypt(key, object, &symmetric_key)) if (key->eme_pkcs1_decrypt(key, object, &symmetric_key) != SUCCESS)
{ {
DBG1("symmetric key could not be decrypted with rsa"); DBG1("symmetric key could not be decrypted with rsa");
goto failed; goto failed;
@@ -533,23 +534,24 @@ bool pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data,
} }
break; break;
case PKCS7_CONTENT_ENC_ALGORITHM: case PKCS7_CONTENT_ENC_ALGORITHM:
content_enc_alg = parse_algorithmIdentifier(object, level, &iv); {
int alg = parse_algorithmIdentifier(object, level, &iv);
switch (content_enc_alg) switch (alg)
{ {
case OID_DES_CBC: case OID_DES_CBC:
total_keys = 1; crypter = crypter_create(ENCR_DES, 0);
break; break;
case OID_3DES_EDE_CBC: case OID_3DES_EDE_CBC:
total_keys = 3; crypter = crypter_create(ENCR_3DES, 0);
break; break;
default: default:
DBG1("Only DES and 3DES supported for symmetric encryption"); DBG1("Only DES and 3DES supported for symmetric encryption");
goto failed; goto failed;
} }
if (symmetric_key.len != (total_keys * DES_CBC_BLOCK_SIZE)) if (symmetric_key.len != crypter->get_key_size(crypter))
{ {
DBG1("key length is not %d", (total_keys * DES_CBC_BLOCK_SIZE)); DBG1("symmetric key has wrong length");
goto failed; goto failed;
} }
if (!parse_asn1_simple_object(&iv, ASN1_OCTET_STRING, level+1, "IV")) if (!parse_asn1_simple_object(&iv, ASN1_OCTET_STRING, level+1, "IV"))
@@ -557,11 +559,12 @@ bool pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data,
DBG1("IV could not be parsed"); DBG1("IV could not be parsed");
goto failed; goto failed;
} }
if (iv.len != DES_CBC_BLOCK_SIZE) if (iv.len != crypter->get_block_size(crypter))
{ {
plog("IV has wrong length"); DBG1("IV has wrong length");
goto failed; goto failed;
} }
}
break; break;
case PKCS7_ENCRYPTED_CONTENT: case PKCS7_ENCRYPTED_CONTENT:
encrypted_content = object; encrypted_content = object;
@@ -571,54 +574,21 @@ bool pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data,
} }
/* decrypt the content */ /* decrypt the content */
{ crypter->decrypt(crypter, encrypted_content, iv, &this->data);
u_int i; DBG4("decrypted content with padding: %B", &this->data);
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);
}
DBG4("decrypted content with padding: %B", data);
}
/* remove the padding */ /* remove the padding */
{ {
u_char *pos = data->ptr + data->len - 1; u_char *pos = this->data.ptr + this->data.len - 1;
u_char pattern = *pos; u_char pattern = *pos;
size_t padding = pattern; size_t padding = pattern;
if (padding > data->len) if (padding > this->data.len)
{ {
DBG1("padding greater than data length"); DBG1("padding greater than data length");
goto failed; goto failed;
} }
data->len -= padding; this->data.len -= padding;
while (padding-- > 0) while (padding-- > 0)
{ {
@@ -629,284 +599,94 @@ bool pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data,
} }
} }
} }
crypter->destroy(crypter);
free(symmetric_key.ptr); free(symmetric_key.ptr);
return TRUE; return TRUE;
failed: failed:
DESTROY_IF(crypter);
free(symmetric_key.ptr); free(symmetric_key.ptr);
pfreeany(data->ptr); chunk_free(&this->data);
return FALSE; return FALSE;
} }
/** /**
* @brief Builds a contentType attribute * Implements pkcs7_t.destroy
*
* @return ASN.1 encoded contentType attribute
*/ */
chunk_t pkcs7_contentType_attribute(void) static void destroy(private_pkcs7_t *this)
{ {
return asn1_wrap(ASN1_SEQUENCE, "cm" this->certs->destroy(this->certs);
, ASN1_contentType_oid free(this->data.ptr);
, asn1_simple_object(ASN1_SET, ASN1_pkcs7_data_oid)); free(this);
} }
/** /**
* @brief Builds a messageDigest attribute * Parse PKCS#7 contentInfo object
*
*
* @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) static bool parse_contentInfo(chunk_t blob, u_int level0, private_pkcs7_t *cInfo)
{ {
u_char digest_buf[MAX_DIGEST_LEN]; asn1_ctx_t ctx;
chunk_t digest = { digest_buf, MAX_DIGEST_LEN }; chunk_t object;
u_int level;
int objectID = 0;
compute_digest(content, digest_alg, &digest); asn1_init(&ctx, blob, level0, FALSE, FALSE);
return asn1_wrap(ASN1_SEQUENCE, "cm" while (objectID < PKCS7_INFO_ROOF)
, ASN1_messageDigest_oid {
, asn1_wrap(ASN1_SET, "m" if (!extract_object(contentInfoObjects, &objectID, &object, &level, &ctx))
, asn1_simple_object(ASN1_OCTET_STRING, digest) {
) return FALSE;
);
} }
/** if (objectID == PKCS7_INFO_TYPE)
* build a DER-encoded contentInfo object {
cInfo->type = known_oid(object);
if (cInfo->type < OID_PKCS7_DATA
|| cInfo->type > OID_PKCS7_ENCRYPTED_DATA)
{
DBG1("unknown pkcs7 content type");
return FALSE;
}
}
else if (objectID == PKCS7_INFO_CONTENT)
{
cInfo->content = object;
}
objectID++;
}
return TRUE;
}
/*
* Described in header.
*/ */
static chunk_t pkcs7_build_contentInfo(contentInfo_t *cInfo) pkcs7_t *pkcs7_create_from_chunk(chunk_t chunk, u_int level)
{ {
chunk_t content_type; private_pkcs7_t *this = malloc_thing(private_pkcs7_t);
/* select DER-encoded OID for pkcs7 contentInfo type */ /* initialize */
switch(cInfo->type) this->type = OID_UNKNOWN;
this->content = chunk_empty;
this->parsed = FALSE;
this->level = level + 2;
this->data = chunk_empty;
this->attributes = chunk_empty;
this->certs = linked_list_create();
/*public functions */
this->public.is_data = (bool (*) (pkcs7_t*))is_data;
this->public.is_signedData = (bool (*) (pkcs7_t*))is_signedData;
this->public.is_envelopedData = (bool (*) (pkcs7_t*))is_envelopedData;
this->public.parse_data = (bool (*) (pkcs7_t*))parse_data;
this->public.parse_signedData = (bool (*) (pkcs7_t*,x509_t*))parse_signedData;
this->public.parse_envelopedData = (bool (*) (pkcs7_t*,chunk_t,rsa_private_key_t*))parse_envelopedData;
this->public.destroy = (void (*) (pkcs7_t*))destroy;
if (!parse_contentInfo(chunk, level, this))
{ {
case OID_PKCS7_DATA: destroy(this);
content_type = ASN1_pkcs7_data_oid; return NULL;
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:
DBG1("invalid pkcs7 contentInfo type");
return chunk_empty;
}
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 x509_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 x509_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);
DBG3("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, const x509_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");
DBG2("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);
DBG3("padded unencrypted data: %B", &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;
}
DBG2("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");
}
}
/* TODO DBG4("DES key: %#B", 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);
DBG3("DES IV : %#B", &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);
}
DBG3(("Encrypted data: %B", &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);
DBG3("envelopedData: %B", &cInfo);
free_RSA_public_content(&public_key);
free(envelopedData.content.ptr);
return cInfo;
} }
return &this->public;
} }
src/libstrongswan/crypto/pkcs7.h
+55 -17
View File
@@ -27,7 +27,7 @@
#ifndef _PKCS7_H #ifndef _PKCS7_H
#define _PKCS7_H #define _PKCS7_H
typedef struct pkcs7_contentInfo_t pkcs7_contentInfo_t; typedef struct pkcs7_t pkcs7_t;
#include <library.h> #include <library.h>
#include <crypto/x509.h> #include <crypto/x509.h>
@@ -44,37 +44,75 @@ typedef struct pkcs7_contentInfo_t pkcs7_contentInfo_t;
* *
* @ingroup crypto * @ingroup crypto
*/ */
struct pkcs7_contentInfo_t { struct pkcs7_t {
/** /**
* @brief Is contentInfo object of type signedData?. * @brief Check if the PKCS#7 contentType is data
* *
* @param this calling object * @param this calling object
* @return TRUE if of type signedData * @return TRUE if the contentType is data
*/ */
bool (*is_signedData) (pkcs7_contentInfo_t *this); bool (*is_data) (pkcs7_t *this);
/** /**
* @brief Is contentInfo object of type envelopedData?. * @brief Check if the PKCS#7 contentType is signedData
* *
* @param this calling object * @param this calling object
* @return TRUE if of type envelopedData * @return TRUE if the contentType is signedData
*/ */
bool (*is_envelopedData) (pkcs7_contentInfo_t *this); bool (*is_signedData) (pkcs7_t *this);
/**
* @brief Check if the PKCS#7 contentType is envelopedData
*
* @param this calling object
* @return TRUE if the contentType is envelopedData
*/
bool (*is_envelopedData) (pkcs7_t *this);
/**
* @brief Parse a PKCS#7 data content.
*
* @param this calling object
* @return TRUE if parsing was successful
*/
bool (*parse_data) (pkcs7_t *this);
/**
* @brief Parse a PKCS#7 signedData content.
*
* @param this calling object
* @param cacert cacert used to verify the signature
* @return TRUE if parsing was successful
*/
bool (*parse_signedData) (pkcs7_t *this, x509_t *cacert);
/**
* @brief Parse a PKCS#7 envelopedData content.
*
* @param this calling object
* @param serialNumber serialNumber of the request
* @param key RSA private key used to decrypt the symmetric key
* @return TRUE if parsing was successful
*/
bool (*parse_envelopedData) (pkcs7_t *this, chunk_t serialNumber, rsa_private_key_t *key);
/** /**
* @brief Destroys the contentInfo object. * @brief Destroys the contentInfo object.
* *
* @param this contentInfo object to destroy * @param this PKCS#7 contentInfo object to destroy
*/ */
void (*destroy) (pkcs7_contentInfo_t *this); void (*destroy) (pkcs7_t *this);
}; };
extern chunk_t pkcs7_contentType_attribute(void); /**
extern chunk_t pkcs7_messageDigest_attribute(chunk_t content, int digest_alg); * @brief Read a PKCS#7 contentInfo object from a DER encoded chunk.
extern chunk_t pkcs7_build_issuerAndSerialNumber(const x509_t *cert); *
extern chunk_t pkcs7_build_signedData(chunk_t data, chunk_t attributes * @param chunk chunk containing DER encoded data
,const x509_t *cert, int digest_alg, const rsa_private_key_t *key); * @param level ASN.1 parsing start level
extern chunk_t pkcs7_build_envelopedData(chunk_t data, const x509_t *cert * @return created pkcs7_contentInfo object, or NULL if invalid.
, int cipher); *
* @ingroup crypto
*/
pkcs7_t *pkcs7_create_from_chunk(chunk_t chunk, u_int level);
#endif /* _PKCS7_H */ #endif /* _PKCS7_H */