We continue to
talk about the alternative to openssl, and we’ll talk about the
libksba library, which is part of GnuPG. The libksba library provides a high-level interface for working with public key infrastructure objects such as certificates, certificate requests, electronic signatures (CMS / PKCS # 7). However, unlike the GCrypt library, which supports Russian cryptographic algorithms, libksba does not implement
TK-26 recommendations on the use of GOST R 34.10-2001 / 2012, GOST R 34.11-94 / 2012 algorithms in such PKI objects as certificates, requests for certificates, PKCS # 7 / CMS objects (signed and / or encrypted documents, etc.).
Let's start with oids, which can (or should) be included in the DN (Distinguished Name - distinguished name) of the attributes issuer (publisher) and subject (owner) of the certificate. In the library libksba oid-s are written in the structure oid_name_tbl [] (file dn.c). In the structure of oid_name_tbl [] there are no
oid- s INN, OGRN, OGRNP and SNILS
recommended by TC-26 for a qualified certificate:
18. Additional attributes of the name, the need to use which is established in accordance with federal law, include:
1) OGRN.
The value of the OGRN attribute is a string consisting of 13 digits and representing the OGRN of the owner of a qualified certificate - a legal entity. The object identifier of the attribute type OGRN is 1.2.643.100.1, the attribute type OGRN is described as follows: OGRN :: = NUMERIC STRING SIZE 13;
2) SNILS (SNILS).
The value of the SNILS attribute is a string consisting of 11 digits representing the SNILS of the owner of a qualified certificate - an individual. The object identifier of the attribute type SNILS is 1.2.643.100.3, the attribute type SNILS is described as follows: SNILS :: = NUMERIC STRING SIZE 11;
3) INN (INN).
The value of the INN attribute is a 12-digit string representing the TIN of the owner of the qualified certificate. The object identifier of the type of the INN attribute is 1.2.643.3.131.1.1, the attribute type of the INN is described as follows: INN :: = NUMERIC STRING SIZE 12.
Naturally, you need to add these oids:
static const struct { const char *name; int source; const char *description; size_t oidlen; const unsigned char *oid; const char *oidstr; } oid_name_tbl[] = { {"CN", 1, "CommonName", 3, "\x55\x04\x03", "2.5.4.3" }, {"SN", 2, "Surname", 3, "\x55\x04\x04", "2.5.4.4" }, {"SERIALNUMBER", 2, "SerialNumber",3, "\x55\x04\x05", "2.5.4.5" }, {"C", 1, "CountryName", 3, "\x55\x04\x06", "2.5.4.6" }, {"L" , 1, "LocalityName", 3, "\x55\x04\x07", "2.5.4.7" }, {"ST", 1, "StateOrProvince", 3, "\x55\x04\x08", "2.5.4.8" }, {"STREET", 1, "StreetAddress", 3, "\x55\x04\x09", "2.5.4.9" }, {"O", 1, "OrganizationName", 3, "\x55\x04\x0a", "2.5.4.10" }, {"OU", 1, "OrganizationalUnit", 3, "\x55\x04\x0b", "2.5.4.11" }, {"T", 2, "Title", 3, "\x55\x04\x0c", "2.5.4.12" }, {"D", 3, "Description", 3, "\x55\x04\x0d", "2.5.4.13" }, {"BC", 3, "BusinessCategory", 3, "\x55\x04\x0f", "2.5.4.15" }, {"ADDR", 2, "PostalAddress", 3, "\x55\x04\x11", "2.5.4.16" }, {"POSTALCODE" , 0, "PostalCode", 3, "\x55\x04\x11", "2.5.4.17" }, {"GN", 2, "GivenName", 3, "\x55\x04\x2a", "2.5.4.42" }, {"PSEUDO", 2, "Pseudonym", 3, "\x55\x04\x41", "2.5.4.65" }, {"DC", 1, "domainComponent", 10, "\x09\x92\x26\x89\x93\xF2\x2C\x64\x01\x19", "0.9.2342.19200300.100.1.25" }, {"UID", 1, "userid", 10, "\x09\x92\x26\x89\x93\xF2\x2C\x64\x01\x01", "0.9.2342.19200300.100.1.1 " }, {"E", 1, "emailAddress", 9, "\x2A\x86\x48\x86\xF7\x0D\x01\x09\x01", "1.2.840.113549.1.9.1" }, {"OGRN", 4, "OGRN", 5, "\x2a\x85\x03\x64\x01", "1.2.643.100.1" }, {"INN", 4, "INN", 8, "\x2a\x85\x03\x03\x81\x03\x01\x01", "1.2.643.3.131.1.1" }, {"SNILS", 4, "SNILS", 5, "\x2a\x85\x03\x64\x03", "1.2.643.100.3" }, {"OGRNIP", 4, "OGRNIP", 5, "\x2a\x85\x03\x64\x05", "1.2.643.100.5" }, { NULL } };
What is remarkable in this structure is the presence of the source field, which indicates who entered a particular field, for example, 1 (one) indicates that the field is defined in rfc2253, and 4 (four) added here will be indicate that the field is recommended by the technical committee of TC-26. In accordance with the recommendations of TC-26, the attributes of TIN, OGRN, OGRNP and SNILS are of type NUMERIC STRING (see above). The processing of the oids included in the DN in libksba is provided in the append_atv function (dn.c file), but it does not contain the type TYPE_NUMERIC_STRING, and you should add it:
. . . switch (use_hex? 0 : node->type) { case TYPE_UTF8_STRING: append_utf8_value (image+node->off+node->nhdr, node->len, sb); break; case TYPE_NUMERIC_STRING: case TYPE_PRINTABLE_STRING: ….
The patch for the dn.c file is here: Save it in the diff_dn.patch file.
The libksba library can be downloaded
here . Unzip the archive, go to the src directory and apply patch diff_dn.patch to the dn.c file:
$patch dn.c < diff_dn.patch $
In addition to the DN attributes oid-s, you must also add the oids of the GOST-based keys to the structure struct pk_algo_table [] (keyihfo.c file):
static const struct algo_table_s pk_algo_table[] = { { "1.2.840.113549.1.1.1", "\x2a\x86\x48\x86\xf7\x0d\x01\x01\x01", 9, 1, PKALGO_RSA, "rsa", "-ne", "\x30\x02\x02" }, . . . { "1.2.643.2.2.19", "\x2a\x85\x03\x02\x02\x13", 6, 1, PKALGO_ECC, "ecc", "q", "\x80" }, { "1.2.643.7.1.1.1.1", "\x2a\x85\x03\x07\x01\x01\x01\x01", 8, 1, PKALGO_ECC, "ecc", "q", "\x80" }, { "1.2.643.7.1.1.1.2", "\x2a\x85\x03\x07\x01\x01\x01\x02", 8, 1, PKALGO_ECC, "ecc", "q", "\x80" }, {NULL} };
Similarly, in the structure sig_algo_table [] (keyihfo.c file) we add oid-s associated with the electronic signature in accordance with GOST:
static const struct algo_table_s sig_algo_table[] = { { "1.2.840.113549.1.1.5", "\x2A\x86\x48\x86\xF7\x0D\x01\x01\x05", 9, 1, PKALGO_RSA, "rsa", "s", "\x82", NULL, NULL, "sha1" }, . . . { "1.2.643.2.2.19", "\x2a\x85\x03\x02\x02\x13", 6, 1, PKALGO_ECC, "gost", "s", "\x80", NULL, NULL, "gostr3411_CP" }, { "1.2.643.7.1.1.1.1", "\x2a\x85\x03\x07\x01\x01\x01\x01", 8, 1, PKALGO_ECC, "gost", "s", "\x80", NULL, NULL, "stribog256"}, { "1.2.643.7.1.1.1.2", "\x2a\x85\x03\x07\x01\x01\x01\x02", 8, 1, PKALGO_ECC, "gost", "s", "\x80", NULL, NULL, "stribog512"}, { "1.2.643.7.1.1.3.2", "\x2a\x85\x03\x07\x01\x01\x03\x02", 8, 1, PKALGO_ECC, "gost", "s", "\x80", NULL, NULL, "stribog256" }, { "1.2.643.7.1.1.3.3", "\x2a\x85\x03\x07\x01\x01\x03\x03", 8, 1, PKALGO_ECC, "gost", "s", "\x80", NULL, NULL, "stribog512" }, { "1.2.643.2.2.3", "\x2a\x85\x03\x02\x02\x03", 6, 1, PKALGO_ECC, "gost", "s", "\x80", NULL, NULL, "gostr3411_CP" }, {NULL} };
And finally, we add the structure enc_algo_table [] oid-s of GOST-keys, which can participate in asymmetric encryption (PKCS # 7):
static const struct algo_table_s enc_algo_table[] = { { "1.2.840.113549.1.1.1", "\x2A\x86\x48\x86\xF7\x0D\x01\x01\x01", 9, 1, PKALGO_RSA, "rsa", "a", "\x82" }, { "1.2.643.2.2.19", "\x2A\x85\x03\x02\x02\x13", 6, 1, PKALGO_ECC, "ecc", "a", "\x80" }, { "1.2.643.7.1.1.1.1", "\x2A\x85\x03\x07\x01\x01\x01\x01", 8, 1, PKALGO_ECC, "ecc", "a", "\x80" }, { "1.2.643.7.1.1.1.2", "\x2A\x85\x03\x07\x01\x01\x01\x02", 8, 1, PKALGO_ECC, "ecc", "a", "\x80" }, {NULL} };
Now that we have decided on the OIDs, let's move on to the storage structure of the public key in the certificate. In general, the SubjectPublicKeyInfo structure in the certificate has the following form:
SubjectPublicKeyInfo ::= SEQUENCE { algorithm OBJECT IDENTIFIER GostR3410-2001/2012-PublicKeyParameters ::= SEQUENCE { publicKeyParamSet OBJECT IDENTIFIER, digestParamSet OBJECT IDENTIFIER, encryptionParamSet OBJECT IDENTIFIER } subjectKey BIT STRING }
The publicKeyParamSet parameter sets the oid of the elliptic curve point. Oids of allowed points are written in the structure of struct curve_aliases [] in the libccrypt library ecc_curves.c file. In the libksba library, these oids are registered in the struct curve_names [] structure in the keyinfo.c file. In this structure, the oids "1.2.643.2.2.36.0" (GOST2001-CryptoPro-XchA) and "1.2.643.2.2.36.1.1" (GOST2001-CryptoPro-XchB) are omitted. Let's add these oids, but taking into account the fact that the oid "1.2.643.2.2.36.0" is actually a point with the oid "1.2.643.2.2.35.1", and "1.2.643.2.2.36.1" corresponds to oid-1.2.643.2.2.35.3:
static const struct { const char *oid; const char *name; } curve_names[] = { { "1.3.6.1.4.1.3029.1.5.1", "Curve25519" }, . . . { "1.2.643.2.2.35.3", "GOST2001-CryptoPro-C" },
The encryptionParamSet parameter is usually omitted. The digestParamSet parameter can also be omitted: the type of the GOST key uniquely identifies the oid digestParamSet.
The code involved in extracting the public key from the GOST certificate, parsing it and packing it into the S-variable was added to the _ksba_keyinfo_to_sexp function (keyinfo.c file), and the code responsible for packing the GOST signature into the S-variable was added to the function crypt_val_to_sexp. The code is provided with comments and does not require additional explanations. We already spoke about the peculiarities of storing the public key and the signature in the certificate in the
previous article.
The patch for the keyinfo.c file is here: Save it in the diff_keyinfo.patch file and apply it to the keyinfo.c file:
$patch keyinfo.c < diff_keyinfo.patch $
After adding these patches you can build a library. If the assembled library libksba.so.8.11.6 is not going to be put into the system, but will be used only for testing, then it is convenient to copy it into the directory in which test examples will be collected. These patches are enough to parse certificates with GOST keys, as well as signed documents with GOST keys in the PKCS # 7 format, and extract and verify the mathematical accuracy of the X509 certificate electronic signature or the electronic signature of the PKCS # 7 / CMS document.
To test the done, consider two software modules. The first check_cert module checks the certificate signature, and the second check_cms_signed module checks the integrity of the signed document (CMS / PKCS # 7) and the document signature. Recall that the validity of the certificate is not only determined by the correctness of its signature, but also by its validity (non-rectification) at the checked point in time. In the same way, the validity of the signature under the document is determined not only by the mathematical accuracy of the signature, but also by the validity of the signer's certificate.
To create a signed document in the PKCS # 7 format, you can use the
guinss.exe utility written in Python with Tkinter, and use
PKCS # 11 tokens using Russian cryptography as cryptographic information protection tools (ICTD):
Note also that the PKCS # 7 format of the electronic signature of the document in question implies the inclusion of the signatory’s certificate in the signature. This is done so that the example does not become immense.
The source code of the certificate signature verification utility check_cert.c is shown here: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include <errno.h> #include <ctype.h> #include <gcrypt.h> #include <ksba.h> /* Hash function used with libksba. */ #define HASH_FNC ((void (*)(void *, const void*,size_t))gcry_md_write) /* S-*/ static void show_sexp (const char *prefix, gcry_sexp_t a) { char *buf; size_t size; if (prefix) fputs (prefix, stderr); size = gcry_sexp_sprint (a, GCRYSEXP_FMT_ADVANCED, NULL, 0); buf = gcry_xmalloc (size); gcry_sexp_sprint (a, GCRYSEXP_FMT_ADVANCED, buf, size); fprintf (stderr, "%.*s", (int)size, buf); gcry_free (buf); } /* */ static gpg_error_t check_cert_sig (ksba_cert_t issuer_cert, ksba_cert_t cert) { gpg_error_t err; const char *algoid; gcry_md_hd_t md; int i, algo; ksba_sexp_t p; size_t n; /* : S_PKEY - S- . S_SIG - S- S_HASH - S- tbs- */ gcry_sexp_t s_sig, s_hash, s_pkey; const char *s; char algo_name[16+1]; /* hash algorithm name converted to lower case. */ int digestlen; unsigned char *digest; int gost_key; /* Hash the target certificate using the algorithm from that certificate. */ algoid = ksba_cert_get_digest_algo (cert); algo = gcry_md_map_name (algoid); if (!algo) { fprintf(stderr, "unknown hash algorithm `%s'\n", algoid? algoid:"?"); return (-1); } /* */ gost_key = !memcmp(algoid, "1.2.643", 7); s = gcry_md_algo_name (algo); for (i=0; *s && i < sizeof algo_name - 1; s++, i++) algo_name[i] = tolower (*s); algo_name[i] = 0; err = gcry_md_open (&md, algo, 0); if (err) { fprintf(stderr, "md_open failed: %s\n", algoid); return err; } err = ksba_cert_hash (cert, 1, HASH_FNC, md); if (err) { fprintf(stderr, "ksba_cert_hash failed: %s\n", algoid); gcry_md_close (md); return err; } gcry_md_final (md); /* */ p = ksba_cert_get_sig_val (cert); /* */ n = gcry_sexp_canon_len (p, 0, NULL, NULL); if (!n) { gcry_md_close (md); ksba_free (p); return (-1); } /* S- libgcrypt*/ err = gcry_sexp_sscan ( &s_sig, NULL, p, n); ksba_free (p); if (err) { fprintf(stderr, "gcry_sexp_scan failed: %s\n", "Beda"); gcry_md_close (md); return err; } /* S- */ show_sexp ("Sig value:\n", s_sig); /* */ p = ksba_cert_get_public_key (issuer_cert); n = gcry_sexp_canon_len (p, 0, NULL, NULL); if (!n) { fprintf(stderr, "libksba did not return a proper S-Exp\n"); gcry_md_close (md); ksba_free (p); gcry_sexp_release (s_sig); return (-1); } err = gcry_sexp_sscan ( &s_pkey, NULL, p, n); ksba_free (p); if (err) { fprintf(stderr, "gcry_sexp_scan failed: %s\n", "pubkey"); gcry_md_close (md); gcry_sexp_release (s_sig); return err; } /* S- */ show_sexp ("s_pkey:\n", s_pkey); digestlen = gcry_md_get_algo_dlen (algo); digest = gcry_md_read (md, algo); if (gost_key){ unsigned char *h; unsigned char c; int len_xy; /* littlt-endian big-endian*/ unsigned short arch = 1; /* 0x0001 */ h = digest; len_xy = *((unsigned char *) &arch) == 0 ? 0:gcry_md_get_algo_dlen (algo); /* */ for (i = 0; i < (len_xy/2); i++) { c = *(h + i); *(h + i) = *(h + len_xy - i - 1); *(h + len_xy - i - 1) = c; } } switch (gost_key) { case 0: if ( gcry_sexp_build (&s_hash, NULL, "(data(flags pkcs1)(hash %s %b))", algo_name, (int)digestlen, digest) ) { exit (1); } break; case 1: if ( gcry_sexp_build (&s_hash, NULL, "(data(flags gost)(value %b))", (int)digestlen, digest) ) { exit (1); } break; default: exit (1); } /* S- tbs-*/ show_sexp ("s_hash:\n", s_hash); /* */ err = gcry_pk_verify (s_sig, s_hash, s_pkey); /* */ gcry_md_close (md); gcry_sexp_release (s_sig); gcry_sexp_release (s_hash); gcry_sexp_release (s_pkey); return err; } int main (int argc, unsigned char *argv[]) { FILE *fp; ksba_reader_t r; ksba_cert_t cert; FILE *fp_ca; ksba_reader_t r_ca; ksba_cert_t cert_ca; gpg_error_t err; unsigned char *sub_dn; if(argc != 3) { fprintf(stderr, "Usage: check_cert < > < >\n"); exit(1); } fp = fopen (argv[1], "rb"); if (!fp) { fprintf (stderr, "check_cert: can't open `%s'\n", argv[1]); exit (1); } err = ksba_reader_new (&r); if (err) { fprintf(stderr, "ksba_reader_new error\n"); exit(1); } err = ksba_reader_set_file (r, fp); if (err) { fprintf(stderr, "ksba_reader_set error\n"); exit(1); } err = ksba_cert_new (&cert); if (err){ fprintf(stderr, "ksba_cert_new error\n"); exit(1); } err = ksba_cert_read_der (cert, r); if (err){ fprintf(stderr, "ksba_cert_read_der error\n"); exit(1); } fp_ca = fopen (argv[2], "rb"); if (!fp_ca) { fprintf (stderr, "check_cert: can't open `%s'\n", argv[2]); exit (1); } err = ksba_reader_new (&r_ca); if (err) { fprintf(stderr, "ksba_reader_new error\n"); exit(1); } err = ksba_reader_set_file (r_ca, fp_ca); if (err) { fprintf(stderr, "ksba_reader_set error\n"); exit(1); } err = ksba_cert_new (&cert_ca); if (err){ fprintf(stderr, "ksba_cert_new error\n"); exit(1); } err = ksba_cert_read_der (cert_ca, r_ca); if (err){ fprintf(stderr, "ksba_cert_read_der error\n"); exit(1); } sub_dn = ksba_cert_get_subject (cert, 0); fprintf(stderr, "check_cert: Verify %s\n", sub_dn); err = check_cert_sig (cert_ca, cert); if (err) { fprintf(stderr, "check_cert: verify %s error\n", argv[1]); } else { fprintf(stderr, "check_cert: verify %s Ok\n", argv[1]); } }
Save the code in the file check_cert.c, translate it and run:
bash-4.3$ln –s libksba.so.8 lgcrypt libksba.so.8.11.6 bash-4.3$ cc -o check_cert check_cert.c -lgcrypt libksba.so.8.11.6 bash-4.3$ ./check_cert Usage: check_cert < > < > bash-4.3$
So, to verify the certificate, you must have the certificate itself and the CA certificate (for example, you can take it from the previous article) on which it was issued. Certificates must be (yet) in DER-coding:
bash-4.3$ ./check_cert CERT_CMS_KSBA.der CAcert_NEWCA.der check_cert: Verify SNILS=22222222222,INN=123456789012,O=CMS,STREET=PKCS7,L= ,ST=50 ,C=RU,GN=KSBA,SN=GCrypt,CN= GCrypt and KSBA,E=test@test.ru Sig value: (sig-val (gost (r
To verify a self-signed certificate, the latter is specified as both verifiable and root certificate:
bash-4.3$ ./check_cert CAcert_NEWCA.der CAcert_NEWCA.der check_cert: Verify E=info@ooo.ru,CN= ,OU= 2,O= ,C=RU,ST= ,L=. . . . check_cert: verify CAcert_NEWCA.der Ok bash-4.3$
So we have a simple utility for verifying the signature of certificates.
To check the electronic signature of documents in the format PKCS # 7 developed
test utility check_cms_signed.c: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include <time.h> #include <errno.h> #include <ksba.h> //#include "t-common.h" #include <gcrypt.h> #include <sys/stat.h> #include <sys/types.h> #include <fcntl.h> #include <unistd.h> /* Hash function used with libksba. */ #define HASH_FNC ((void (*)(void *, const void*,size_t))gcry_md_write) void dump_isotime (const ksba_isotime_t t) { if (!t || !*t) fprintf (stderr, "[none]"); else fprintf (stderr,"%.4s-%.2s-%.2s %.2s:%.2s:%s", t, t+4, t+6, t+9, t+11, t+13); } static void show_sexp (const char *prefix, gcry_sexp_t a) { char *buf; size_t size; if (prefix) fputs (prefix, stderr); size = gcry_sexp_sprint (a, GCRYSEXP_FMT_ADVANCED, NULL, 0); buf = gcry_xmalloc (size); gcry_sexp_sprint (a, GCRYSEXP_FMT_ADVANCED, buf, size); fprintf (stderr, "%.*s", (int)size, buf); gcry_free (buf); } void dummy_hash_fnc (void *arg, const void *buffer, size_t length) { (void)arg; (void)buffer; (void)length; } static int dummy_writer_cb (void *cb_value, const void *buffer, size_t count) { (void)cb_value; (void)buffer; (void)count; return 0; } /* */ unsigned char *dgst_file (char *oid, char* fcont, int *len_h) { gcry_md_hd_t hd; gcry_error_t err; int algo; FILE *fp; unsigned char buf[1024]; size_t size; int i; unsigned char *h; unsigned char *ret_h; algo = gcry_md_map_name (oid); if (algo == GCRY_MD_NONE) return NULL; err = gcry_md_open(&hd, algo, 0); if (err) return NULL; fp = fopen (fcont, "r"); if (fp == NULL) return NULL; while (!feof (fp)) { size = fread (buf, 1, sizeof(buf), fp); gcry_md_write (hd, buf, size); } h = gcry_md_read(hd, 0); *len_h = gcry_md_get_algo_dlen (algo); ret_h = malloc(*len_h); memcpy(ret_h, h, *len_h); gcry_md_reset(hd); gcry_md_close(hd); return ret_h; } gcry_error_t one_file (const char *fname, char *fcontent, char *fcert) { gcry_error_t err; FILE *fp; ksba_reader_t r; ksba_writer_t w; ksba_cms_t cms; int i; const char *algoid; ksba_stop_reason_t stopreason; const char *s = NULL; size_t n; ksba_sexp_t p; char *dn; int idx; ksba_cert_t cert; int ii; unsigned char *cert_der; int cert_der_len; int f_der; int rez; ksba_sexp_t p1; size_t n1; gcry_sexp_t s_sig, s_hash, s_pkey, s_num; int gost_key; gcry_md_hd_t md; int rc; int digestlen; unsigned char *digest; gcry_md_hd_t data_md = NULL; ksba_isotime_t sigtime; unsigned char *sub_dn; //dn - char *is_dn; //dn - ksba_sexp_t sub_p; // fprintf (stderr, "\n*** checking `%s' ***\n", fname); fp = fopen (fname, "r"); if (!fp) { fprintf (stderr, "can't open `%s'\n", fname); exit (1); } err = ksba_reader_new (&r); if (err) { fprintf (stderr, "can't reader `%s'\n", fname); exit (1); } err = ksba_reader_set_file (r, fp); if (err) { fprintf (stderr, "can't reader set `%s'\n", fname); exit (1); } /* Also create a writer so that cms.c won't return an error when writing processed content. */ err = ksba_writer_new (&w); if (err) { exit (1); } err = ksba_writer_set_cb (w, dummy_writer_cb, NULL); if (err) { exit (1); } switch (ksba_cms_identify (r)) { case KSBA_CT_SIGNED_DATA: s = "signed data"; break; case KSBA_CT_DATA: s = "data"; case KSBA_CT_ENVELOPED_DATA: if (s == NULL) s = "enveloped data"; case KSBA_CT_DIGESTED_DATA: if (s == NULL) s = "digested data"; case KSBA_CT_ENCRYPTED_DATA: if (s == NULL) s = "encrypted data"; case KSBA_CT_AUTH_DATA: if (s == NULL) s = "auth data"; default: if (s == NULL) s = "unknown"; printf ("identified as: %s\n", s); exit(1); } err = ksba_cms_new (&cms); if (err) { exit(1); } err = ksba_cms_set_reader_writer (cms, r, w); if (err) { exit(1); } rc = gcry_md_open (&data_md, 0, 0); if (rc) { fprintf (stderr, "md_open failed: \n"); exit(1);; } err = ksba_cms_parse (cms, &stopreason); if (err) { fprintf (stderr, "ksba_cms_parse: cannot parse %s\n", fname); exit(1); } ksba_cms_set_hash_function (cms, dummy_hash_fnc, NULL); do { err = ksba_cms_parse (cms, &stopreason); if (err) { fprintf (stderr, "ksba_cms_parse: cannot parse %s\n", fname); exit(1); } } while (stopreason != KSBA_SR_READY); /* PKCS7 */ cert_der_len = 0; for (ii=0; (cert=ksba_cms_get_cert (cms, ii)); ii++) { cert_der = (unsigned char*)ksba_cert_get_image(cert, (size_t *)&cert_der_len); f_der = open(fcert, O_RDWR|O_TRUNC|O_CREAT, 0666); if (f_der == -1) { fprintf(stderr, "Bad open file=%s for cert\n", cert_der_len, fcert); exit(1); } /* */ rez = write(f_der, cert_der, cert_der_len); close(f_der); /* */ p1 = ksba_cert_get_public_key (cert); n1 = gcry_sexp_canon_len (p1, 0, NULL, NULL); if (!n1) { fprintf(stderr, "libksba did not return a proper S-Exp\n"); exit(1); } err = gcry_sexp_sscan ( &s_pkey, NULL, p1, n1); ksba_free (p1); if (err) { fprintf(stderr, "gcry_sexp_scan failed: %s\n", "pubkey"); exit(1); } /* DN */ sub_dn = ksba_cert_get_subject (cert, 0); ksba_cert_release (cert); } for (idx=0; idx < 1; idx++) { int algo; int info_pkalgo; unsigned char *s; int s_len; int len_h; unsigned char *dgst_h; /* /PKCS#7 DN is_dn sub_p*/ /* */ /* , PKCS#7*/ err = ksba_cms_get_issuer_serial (cms, idx, &is_dn, &sub_p); if (err) { fprintf (stderr, "ksba_cms_get_issuer_serial cannot %s\n", fname); exit(1); } /* */ algoid = ksba_cms_get_digest_algo (cms, idx); err = ksba_cms_get_sigattr_oids (cms, 0, "1.2.840.113549.1.7.1",&dn); if (err && err != -1) { fprintf (stderr, "ksba_cms_get_sigattr_oids cannot %s err=%d\n", fname, err); exit(1); } algo = gcry_md_map_name (algoid); /* - (1) */ gost_key = !memcmp(algoid, "1.2.643", 7); gcry_md_enable (data_md, algo); rc = gcry_md_open (&md, algo, 0); if (rc) { fprintf(stderr, "md_open failed:\n"); exit(1); } /* -*/ ksba_cms_set_hash_function (cms, HASH_FNC, data_md); /* */ rc = ksba_cms_hash_signed_attrs (cms, idx); if (rc) { fprintf(stderr, "hashing signed attrs failed: \n"); gcry_md_close (md); continue; } gcry_md_final (md); digestlen = gcry_md_get_algo_dlen (algo); /* */ digest = gcry_md_read (data_md, algo); gcry_md_close (md); if (gost_key){ /* */ unsigned char *h; unsigned char c; int len_xy; /* littlt-endian big-endian*/ unsigned short arch = 1; /* 0x0001 */ h = digest; len_xy = *((unsigned char *) &arch) == 0 ? 0:gcry_md_get_algo_dlen (algo); /* */ for (i = 0; i < (len_xy/2); i++) { c = *(h + i); *(h + i) = *(h + len_xy - i - 1); *(h + len_xy - i - 1) = c; } } switch (gost_key) { case 0: if ( gcry_sexp_build (&s_hash, NULL, "(data(flags pkcs1)(hash %s %b))", algoid, (int)digestlen, digest) ) { fprintf(stderr, "BUG\n"); exit (1); } break; case 1: /* , S- */ if ( gcry_sexp_build (&s_hash, NULL, "(data(flags gost)(value %b))", (int)digestlen, digest) ) { exit (1); } break; default: exit (1); } /* */ rc = ksba_cms_get_signing_time (cms, idx, sigtime); if (rc) { fprintf(stderr, "error getting signing time\n"); // *sigtime = 0; /* (we can't encode an error in the time string.) */ exit(1); } /* PKCS#7 */ err = ksba_cms_get_message_digest (cms, idx, &dn, &n); if (err) { fprintf (stderr, "ksba_cms_get_message_digest cannot %s\n", fname); exit(1); } /* */ dgst_h = dgst_file ((char *)algoid, (char *)fcontent, &len_h); if (dgst_h == NULL) { fprintf(stderr, "\nBad digest %s\n", fcontent); exit (1); } if (memcmp(dgst_h, dn, n)) { /* : , , ..*/ fprintf(stderr, "\nBad content %s\n", fcontent); exit (1); } ksba_free (dn); putchar ('\n'); dn = ksba_cms_get_sig_val (cms, idx); if (!dn) { printf ("signer %d - signature not found\n", idx); exit(1); } n = gcry_sexp_canon_len ((ksba_sexp_t)dn, 0, NULL, NULL); if (!n){ fprintf(stderr, "libksba did not return a proper S-Exp\n"); exit(1); } err = gcry_sexp_sscan ( &s_sig, NULL, dn, n); if (err){ fprintf(stderr, "gcry_sexp_scan failed: %s\n", "Beda"); exit(1); } ksba_free (dn); } fprintf(stderr, "\n===========================================================\n"); if (*sigtime){ fprintf (stderr, " :\n"); dump_isotime (sigtime); fprintf (stderr, "\n"); } else fprintf (stderr, "[date not given]\n"); fprintf(stderr, "\n : %s\n", sub_dn); fprintf(stderr, "\n : %s\n", is_dn); n = gcry_sexp_canon_len ((ksba_sexp_t)sub_p, 0, NULL, NULL); if (!n){ fprintf(stderr, "libksba did not return a proper S-Exp NUM\n"); exit(1); } err = gcry_sexp_sscan ( &s_num, NULL, sub_p, n); show_sexp ("\n :\n", s_num); fprintf(stderr, "\n===========================================================\n"); /* */ err = gcry_pk_verify (s_sig, s_hash, s_pkey); // if(err) { show_sexp ("s_pkey:\n", s_pkey); show_sexp ("s_sig:\n", s_sig); show_sexp ("s_hash:\n", s_hash); // } ksba_cms_release (cms); ksba_reader_release (r); fclose (fp); return (err); } int main (int argc, char **argv) { gcry_error_t err; unsigned char *h; int *len_h; if(argc != 4) { fprintf(stderr, "Usage: check_cms < > < > < >\n"); exit(1); } err = one_file (argv[1], argv[2], argv[3]); if (err) { fprintf(stderr, "check_cms: verify %s error\n", argv[1]); } else { fprintf(stderr, "check_cms: verify %s Ok\n", argv[1]); fprintf(stderr, "check_cms: %s\n", argv[3]); } exit (0); }
, ( ) . check_cms_signed.c, :
bash-4.3$ cc -o check_cms_signed check_cms_signed.c -lgcrypt libksba.so.8.11.6 bash-4.3$ ./check_cms_signed Usage: check_cms < > < > < > bash-4.3$
:
bash-4.3$ ./check_cms_signed test_cms_ksba.txt.p7s test_cms_ksba.txt save_cert.der *** checking `test_cms_ksba.txt.p7s' *** =========================================================== : 2018-06-25 15:57:12 : SNILS=22222222222,INN=123456789012,O=CMS,STREET=PKCS7,L= ,ST=50 ,C=RU,GN=KSBA,SN=GCrypt,CN= GCrypt and KSBA,E=test@test.ru : E=info@lissi.ru,CN= -,OU= 2,O= -,C=RU,ST= ,L=. ,STREET=. .4 .7,OGRN=1234567890123,INN=123456789012 : (#73102E931BF9EA1369BA#) =========================================================== s_pkey: (public-key (ecc (curve "1.2.643.7.1.2.1.2.2") (hash "1.2.643.7.1.1.2.3") (q #044840A283684ECB537989536B9F080F7B914F3E6C153BC23F8A9212E303BF5B13905D29D0689CA5F2D0715D13FDC0FD387650193A7B46BE20C266776FAE36483750FE52A4C4E35EFB37EA64B48CB50ED5151289F59793574BD5FA59A2048A97FD94A1E5BB8DBF616B776D70C25774C1AC11CD6B6791D15850C37F7F176F49DBB6#) ) ) s_sig: (sig-val (gost (r #430C6EE1C0126F217B58EF5FB2E25055B2DF64AF0A1D769F2E7402145322ACD77B7D537B985AD7F3E3EDE94F9521D2F1E039B6F818B88D1CD709BE7BA97FE5E7#) (s #6A75146760E21BF6FA4CEDB41D37D938D5988DE048F9171796E764EC0E90891A7E02CA7F855C2468E11D217DB5C28DFAB1E31FF45793029FCDD666BE589F646A#) ) (hash stribog512) ) s_hash: (data (flags gost) (value #AD66AC68C832442C9520718AF9F67A87518CFE23098886C075F09DD19AC626DA65D7E39F6E0F81F5CF19C7DC5C3C9CC75FAD26A6C450ADD4C02FD31B49BA7CF1#) ) check_cms: verify test_cms_ksba.txt.p7s Ok check_cms: save_cert.der bash-4.3$
/ , :
bash-4.3$ ./check_cms_signed test_cms_ksba.txt.p7s test_cms_ksba_Change.txt save_cert.der *** checking `test_cms_ksba.txt.p7s' *** Bad content test_cms_ksba_Change.txt bash-4.3$
<
> ( sace_cert.der).
, .
. (PKCS#7, VKO, KEK), , . .