/* $OpenBSD: pk7_smime.c,v 1.27 2024/04/20 10:11:55 tb Exp $ */ /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL * project. */ /* ==================================================================== * Copyright (c) 1999-2004 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * licensing@OpenSSL.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ /* Simple PKCS#7 processing functions */ #include #include #include #include #include "x509_local.h" static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si); PKCS7 * PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs, BIO *data, int flags) { PKCS7 *p7; int i; if (!(p7 = PKCS7_new())) { PKCS7error(ERR_R_MALLOC_FAILURE); return NULL; } if (!PKCS7_set_type(p7, NID_pkcs7_signed)) goto err; if (!PKCS7_content_new(p7, NID_pkcs7_data)) goto err; if (pkey && !PKCS7_sign_add_signer(p7, signcert, pkey, NULL, flags)) { PKCS7error(PKCS7_R_PKCS7_ADD_SIGNER_ERROR); goto err; } if (!(flags & PKCS7_NOCERTS)) { for (i = 0; i < sk_X509_num(certs); i++) { if (!PKCS7_add_certificate(p7, sk_X509_value(certs, i))) goto err; } } if (flags & PKCS7_DETACHED) PKCS7_set_detached(p7, 1); if (flags & (PKCS7_STREAM|PKCS7_PARTIAL)) return p7; if (PKCS7_final(p7, data, flags)) return p7; err: PKCS7_free(p7); return NULL; } LCRYPTO_ALIAS(PKCS7_sign); int PKCS7_final(PKCS7 *p7, BIO *data, int flags) { BIO *p7bio; int ret = 0; if (!(p7bio = PKCS7_dataInit(p7, NULL))) { PKCS7error(ERR_R_MALLOC_FAILURE); return 0; } SMIME_crlf_copy(data, p7bio, flags); (void)BIO_flush(p7bio); if (!PKCS7_dataFinal(p7, p7bio)) { PKCS7error(PKCS7_R_PKCS7_DATASIGN); goto err; } ret = 1; err: BIO_free_all(p7bio); return ret; } LCRYPTO_ALIAS(PKCS7_final); /* Check to see if a cipher exists and if so add S/MIME capabilities */ static int add_cipher_smcap(STACK_OF(X509_ALGOR) *sk, int nid, int arg) { if (EVP_get_cipherbynid(nid)) return PKCS7_simple_smimecap(sk, nid, arg); return 1; } PKCS7_SIGNER_INFO * PKCS7_sign_add_signer(PKCS7 *p7, X509 *signcert, EVP_PKEY *pkey, const EVP_MD *md, int flags) { PKCS7_SIGNER_INFO *si = NULL; STACK_OF(X509_ALGOR) *smcap = NULL; if (!X509_check_private_key(signcert, pkey)) { PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE); return NULL; } if (!(si = PKCS7_add_signature(p7, signcert, pkey, md))) { PKCS7error(PKCS7_R_PKCS7_ADD_SIGNATURE_ERROR); return NULL; } if (!(flags & PKCS7_NOCERTS)) { if (!PKCS7_add_certificate(p7, signcert)) goto err; } if (!(flags & PKCS7_NOATTR)) { if (!PKCS7_add_attrib_content_type(si, NULL)) goto err; /* Add SMIMECapabilities */ if (!(flags & PKCS7_NOSMIMECAP)) { if (!(smcap = sk_X509_ALGOR_new_null())) { PKCS7error(ERR_R_MALLOC_FAILURE); goto err; } if (!add_cipher_smcap(smcap, NID_aes_256_cbc, -1) || !add_cipher_smcap(smcap, NID_aes_192_cbc, -1) || !add_cipher_smcap(smcap, NID_aes_128_cbc, -1) || !add_cipher_smcap(smcap, NID_des_ede3_cbc, -1) || !add_cipher_smcap(smcap, NID_rc2_cbc, 128) || !add_cipher_smcap(smcap, NID_rc2_cbc, 64) || !add_cipher_smcap(smcap, NID_des_cbc, -1) || !add_cipher_smcap(smcap, NID_rc2_cbc, 40) || !PKCS7_add_attrib_smimecap(si, smcap)) goto err; sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free); smcap = NULL; } if (flags & PKCS7_REUSE_DIGEST) { if (!pkcs7_copy_existing_digest(p7, si)) goto err; if (!(flags & PKCS7_PARTIAL) && !PKCS7_SIGNER_INFO_sign(si)) goto err; } } return si; err: if (smcap) sk_X509_ALGOR_pop_free(smcap, X509_ALGOR_free); return NULL; } LCRYPTO_ALIAS(PKCS7_sign_add_signer); /* Search for a digest matching SignerInfo digest type and if found * copy across. */ static int pkcs7_copy_existing_digest(PKCS7 *p7, PKCS7_SIGNER_INFO *si) { int i; STACK_OF(PKCS7_SIGNER_INFO) *sinfos; PKCS7_SIGNER_INFO *sitmp; ASN1_OCTET_STRING *osdig = NULL; sinfos = PKCS7_get_signer_info(p7); for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) { sitmp = sk_PKCS7_SIGNER_INFO_value(sinfos, i); if (si == sitmp) break; if (sk_X509_ATTRIBUTE_num(sitmp->auth_attr) <= 0) continue; if (!OBJ_cmp(si->digest_alg->algorithm, sitmp->digest_alg->algorithm)) { osdig = PKCS7_digest_from_attributes(sitmp->auth_attr); break; } } if (osdig) return PKCS7_add1_attrib_digest(si, osdig->data, osdig->length); PKCS7error(PKCS7_R_NO_MATCHING_DIGEST_TYPE_FOUND); return 0; } int PKCS7_verify(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store, BIO *indata, BIO *out, int flags) { STACK_OF(X509) *signers; X509 *signer; STACK_OF(PKCS7_SIGNER_INFO) *sinfos; PKCS7_SIGNER_INFO *si; X509_STORE_CTX cert_ctx; char buf[4096]; int i, j = 0, k, ret = 0; BIO *p7bio; BIO *tmpin, *tmpout; if (!p7) { PKCS7error(PKCS7_R_INVALID_NULL_POINTER); return 0; } if (!PKCS7_type_is_signed(p7)) { PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE); return 0; } /* Check for no data and no content: no data to verify signature */ if (PKCS7_get_detached(p7) && !indata) { PKCS7error(PKCS7_R_NO_CONTENT); return 0; } /* * Very old Netscape illegally included empty content with * a detached signature. Very old users should upgrade. */ /* Check for data and content: two sets of data */ if (!PKCS7_get_detached(p7) && indata) { PKCS7error(PKCS7_R_CONTENT_AND_DATA_PRESENT); return 0; } sinfos = PKCS7_get_signer_info(p7); if (!sinfos || !sk_PKCS7_SIGNER_INFO_num(sinfos)) { PKCS7error(PKCS7_R_NO_SIGNATURES_ON_DATA); return 0; } signers = PKCS7_get0_signers(p7, certs, flags); if (!signers) return 0; /* Now verify the certificates */ if (!(flags & PKCS7_NOVERIFY)) for (k = 0; k < sk_X509_num(signers); k++) { signer = sk_X509_value (signers, k); if (!(flags & PKCS7_NOCHAIN)) { if (!X509_STORE_CTX_init(&cert_ctx, store, signer, p7->d.sign->cert)) { PKCS7error(ERR_R_X509_LIB); sk_X509_free(signers); return 0; } if (X509_STORE_CTX_set_default(&cert_ctx, "smime_sign") == 0) { sk_X509_free(signers); return 0; } } else if (!X509_STORE_CTX_init(&cert_ctx, store, signer, NULL)) { PKCS7error(ERR_R_X509_LIB); sk_X509_free(signers); return 0; } if (!(flags & PKCS7_NOCRL)) X509_STORE_CTX_set0_crls(&cert_ctx, p7->d.sign->crl); i = X509_verify_cert(&cert_ctx); if (i <= 0) j = X509_STORE_CTX_get_error(&cert_ctx); X509_STORE_CTX_cleanup(&cert_ctx); if (i <= 0) { PKCS7error(PKCS7_R_CERTIFICATE_VERIFY_ERROR); ERR_asprintf_error_data("Verify error:%s", X509_verify_cert_error_string(j)); sk_X509_free(signers); return 0; } /* Check for revocation status here */ } /* * Performance optimization: if the content is a memory BIO then * store its contents in a temporary read only memory BIO. This * avoids potentially large numbers of slow copies of data which will * occur when reading from a read write memory BIO when signatures * are calculated. */ if (indata && (BIO_method_type(indata) == BIO_TYPE_MEM)) { char *ptr; long len; len = BIO_get_mem_data(indata, &ptr); tmpin = BIO_new_mem_buf(ptr, len); if (tmpin == NULL) { PKCS7error(ERR_R_MALLOC_FAILURE); return 0; } } else tmpin = indata; if (!(p7bio = PKCS7_dataInit(p7, tmpin))) goto err; if (flags & PKCS7_TEXT) { if (!(tmpout = BIO_new(BIO_s_mem()))) { PKCS7error(ERR_R_MALLOC_FAILURE); goto err; } BIO_set_mem_eof_return(tmpout, 0); } else tmpout = out; /* We now have to 'read' from p7bio to calculate digests etc. */ for (;;) { i = BIO_read(p7bio, buf, sizeof(buf)); if (i <= 0) break; if (tmpout) BIO_write(tmpout, buf, i); } if (flags & PKCS7_TEXT) { if (!SMIME_text(tmpout, out)) { PKCS7error(PKCS7_R_SMIME_TEXT_ERROR); BIO_free(tmpout); goto err; } BIO_free(tmpout); } /* Now Verify All Signatures */ if (!(flags & PKCS7_NOSIGS)) for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) { si = sk_PKCS7_SIGNER_INFO_value(sinfos, i); signer = sk_X509_value (signers, i); j = PKCS7_signatureVerify(p7bio, p7, si, signer); if (j <= 0) { PKCS7error(PKCS7_R_SIGNATURE_FAILURE); goto err; } } ret = 1; err: if (tmpin == indata) { if (indata) BIO_pop(p7bio); } BIO_free_all(p7bio); sk_X509_free(signers); return ret; } LCRYPTO_ALIAS(PKCS7_verify); STACK_OF(X509) * PKCS7_get0_signers(PKCS7 *p7, STACK_OF(X509) *certs, int flags) { STACK_OF(X509) *signers; STACK_OF(PKCS7_SIGNER_INFO) *sinfos; PKCS7_SIGNER_INFO *si; PKCS7_ISSUER_AND_SERIAL *ias; X509 *signer; int i; if (!p7) { PKCS7error(PKCS7_R_INVALID_NULL_POINTER); return NULL; } if (!PKCS7_type_is_signed(p7)) { PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE); return NULL; } /* Collect all the signers together */ sinfos = PKCS7_get_signer_info(p7); if (sk_PKCS7_SIGNER_INFO_num(sinfos) <= 0) { PKCS7error(PKCS7_R_NO_SIGNERS); return 0; } if (!(signers = sk_X509_new_null())) { PKCS7error(ERR_R_MALLOC_FAILURE); return NULL; } for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(sinfos); i++) { si = sk_PKCS7_SIGNER_INFO_value(sinfos, i); ias = si->issuer_and_serial; signer = NULL; /* If any certificates passed they take priority */ if (certs) signer = X509_find_by_issuer_and_serial (certs, ias->issuer, ias->serial); if (!signer && !(flags & PKCS7_NOINTERN) && p7->d.sign->cert) signer = X509_find_by_issuer_and_serial(p7->d.sign->cert, ias->issuer, ias->serial); if (!signer) { PKCS7error(PKCS7_R_SIGNER_CERTIFICATE_NOT_FOUND); sk_X509_free(signers); return 0; } if (!sk_X509_push(signers, signer)) { sk_X509_free(signers); return NULL; } } return signers; } LCRYPTO_ALIAS(PKCS7_get0_signers); /* Build a complete PKCS#7 enveloped data */ PKCS7 * PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, int flags) { PKCS7 *p7; BIO *p7bio = NULL; int i; X509 *x509; if (!(p7 = PKCS7_new())) { PKCS7error(ERR_R_MALLOC_FAILURE); return NULL; } if (!PKCS7_set_type(p7, NID_pkcs7_enveloped)) goto err; if (!PKCS7_set_cipher(p7, cipher)) { PKCS7error(PKCS7_R_ERROR_SETTING_CIPHER); goto err; } for (i = 0; i < sk_X509_num(certs); i++) { x509 = sk_X509_value(certs, i); if (!PKCS7_add_recipient(p7, x509)) { PKCS7error(PKCS7_R_ERROR_ADDING_RECIPIENT); goto err; } } if (flags & PKCS7_STREAM) return p7; if (PKCS7_final(p7, in, flags)) return p7; err: BIO_free_all(p7bio); PKCS7_free(p7); return NULL; } LCRYPTO_ALIAS(PKCS7_encrypt); int PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags) { BIO *tmpmem; int ret, i; char buf[4096]; if (!p7) { PKCS7error(PKCS7_R_INVALID_NULL_POINTER); return 0; } if (!PKCS7_type_is_enveloped(p7)) { PKCS7error(PKCS7_R_WRONG_CONTENT_TYPE); return 0; } if (cert && !X509_check_private_key(cert, pkey)) { PKCS7error(PKCS7_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE); return 0; } if (!(tmpmem = PKCS7_dataDecode(p7, pkey, NULL, cert))) { PKCS7error(PKCS7_R_DECRYPT_ERROR); return 0; } if (flags & PKCS7_TEXT) { BIO *tmpbuf; /* Encrypt BIOs can't do BIO_gets() so add a buffer BIO */ if (!(tmpbuf = BIO_new(BIO_f_buffer()))) { PKCS7error(ERR_R_MALLOC_FAILURE); BIO_free_all(tmpmem); return 0; } BIO_push(tmpbuf, tmpmem); ret = SMIME_text(tmpbuf, data); if (ret > 0 && BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) { if (!BIO_get_cipher_status(tmpmem)) ret = 0; } BIO_free_all(tmpbuf); return ret; } else { for (;;) { i = BIO_read(tmpmem, buf, sizeof(buf)); if (i <= 0) { ret = 1; if (BIO_method_type(tmpmem) == BIO_TYPE_CIPHER) { if (!BIO_get_cipher_status(tmpmem)) ret = 0; } break; } if (BIO_write(data, buf, i) != i) { ret = 0; break; } } BIO_free_all(tmpmem); return ret; } } LCRYPTO_ALIAS(PKCS7_decrypt);