static int rsa_cms_encrypt(CMS_RecipientInfo *ri)
{
const EVP_MD *md, *mgf1md;
RSA_OAEP_PARAMS *oaep = NULL;
ASN1_STRING *os = NULL;
X509_ALGOR *alg;
EVP_PKEY_CTX *pkctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
int pad_mode = RSA_PKCS1_PADDING, rv = 0, labellen;
unsigned char *label;
CMS_RecipientInfo_ktri_get0_algs(ri, NULL, NULL, &alg);
if (pkctx) {
if (EVP_PKEY_CTX_get_rsa_padding(pkctx, &pad_mode) <= 0)
return 0;
}
if (pad_mode == RSA_PKCS1_PADDING) {
X509_ALGOR_set0(alg, OBJ_nid2obj(NID_rsaEncryption), V_ASN1_NULL, 0);
return 1;
}
/* Not supported */
if (pad_mode != RSA_PKCS1_OAEP_PADDING)
return 0;
if (EVP_PKEY_CTX_get_rsa_oaep_md(pkctx, &md) <= 0)
goto err;
if (EVP_PKEY_CTX_get_rsa_mgf1_md(pkctx, &mgf1md) <= 0)
goto err;
labellen = EVP_PKEY_CTX_get0_rsa_oaep_label(pkctx, &label);
if (labellen < 0)
goto err;
oaep = RSA_OAEP_PARAMS_new();
if (oaep == NULL)
goto err;
if (!rsa_md_to_algor(&oaep->hashFunc, md))
goto err;
if (!rsa_md_to_mgf1(&oaep->maskGenFunc, mgf1md))
goto err;
if (labellen > 0) {
ASN1_OCTET_STRING *los = ASN1_OCTET_STRING_new();
oaep->pSourceFunc = X509_ALGOR_new();
if (oaep->pSourceFunc == NULL)
goto err;
if (los == NULL)
goto err;
if (!ASN1_OCTET_STRING_set(los, label, labellen)) {
ASN1_OCTET_STRING_free(los);
goto err;
}
X509_ALGOR_set0(oaep->pSourceFunc, OBJ_nid2obj(NID_pSpecified),
V_ASN1_OCTET_STRING, los);
}
/* create string with pss parameter encoding. */
if (!ASN1_item_pack(oaep, ASN1_ITEM_rptr(RSA_OAEP_PARAMS), &os))
goto err;
X509_ALGOR_set0(alg, OBJ_nid2obj(NID_rsaesOaep), V_ASN1_SEQUENCE, os);
os = NULL;
rv = 1;
err:
RSA_OAEP_PARAMS_free(oaep);
ASN1_STRING_free(os);
return rv;
}
static RSA_OAEP_PARAMS *rsa_oaep_decode(const X509_ALGOR *alg)
{
RSA_OAEP_PARAMS *oaep;
oaep = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(RSA_OAEP_PARAMS),
alg->parameter);
if (oaep == NULL)
return NULL;
if (oaep->maskGenFunc != NULL) {
oaep->maskHash = rsa_mgf1_decode(oaep->maskGenFunc);
if (oaep->maskHash == NULL) {
RSA_OAEP_PARAMS_free(oaep);
return NULL;
}
}
return oaep;
}
static int rsa_cms_decrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pkctx;
X509_ALGOR *cmsalg;
int nid;
int rv = -1;
unsigned char *label = NULL;
int labellen = 0;
const EVP_MD *mgf1md = NULL, *md = NULL;
RSA_OAEP_PARAMS *oaep;
X509_ALGOR *maskHash;
pkctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
if (!pkctx)
return 0;
if (!CMS_RecipientInfo_ktri_get0_algs(ri, NULL, NULL, &cmsalg))
return -1;
nid = OBJ_obj2nid(cmsalg->algorithm);
if (nid == NID_rsaEncryption)
return 1;
if (nid != NID_rsaesOaep) {
RSAerr(RSA_F_RSA_CMS_DECRYPT, RSA_R_UNSUPPORTED_ENCRYPTION_TYPE);
return -1;
}
/* Decode OAEP parameters */
oaep = rsa_oaep_decode(cmsalg, &maskHash);
if (oaep == NULL) {
RSAerr(RSA_F_RSA_CMS_DECRYPT, RSA_R_INVALID_OAEP_PARAMETERS);
goto err;
}
mgf1md = rsa_mgf1_to_md(oaep->maskGenFunc, maskHash);
if (!mgf1md)
goto err;
md = rsa_algor_to_md(oaep->hashFunc);
if (!md)
goto err;
if (oaep->pSourceFunc) {
X509_ALGOR *plab = oaep->pSourceFunc;
if (OBJ_obj2nid(plab->algorithm) != NID_pSpecified) {
RSAerr(RSA_F_RSA_CMS_DECRYPT, RSA_R_UNSUPPORTED_LABEL_SOURCE);
goto err;
}
if (plab->parameter->type != V_ASN1_OCTET_STRING) {
RSAerr(RSA_F_RSA_CMS_DECRYPT, RSA_R_INVALID_LABEL);
goto err;
}
label = plab->parameter->value.octet_string->data;
/* Stop label being freed when OAEP parameters are freed */
plab->parameter->value.octet_string->data = NULL;
labellen = plab->parameter->value.octet_string->length;
}
if (EVP_PKEY_CTX_set_rsa_padding(pkctx, RSA_PKCS1_OAEP_PADDING) <= 0)
goto err;
if (EVP_PKEY_CTX_set_rsa_oaep_md(pkctx, md) <= 0)
goto err;
if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkctx, mgf1md) <= 0)
goto err;
if (EVP_PKEY_CTX_set0_rsa_oaep_label(pkctx, label, labellen) <= 0)
goto err;
/* Carry on */
rv = 1;
err:
RSA_OAEP_PARAMS_free(oaep);
X509_ALGOR_free(maskHash);
return rv;
}
