/* * pki_gcrypt.c private and public key handling using gcrypt. * * This file is part of the SSH Library * * Copyright (c) 2003-2009 Aris Adamantiadis * Copyright (c) 2009-2011 Andreas Schneider * * The SSH Library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or (at your * option) any later version. * * The SSH Library 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 Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with the SSH Library; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, * MA 02111-1307, USA. */ #include "config.h" #ifdef HAVE_LIBGCRYPT #include #include #include #include #include "libssh/priv.h" #include "libssh/buffer.h" #include "libssh/session.h" #include "libssh/wrapper.h" #include "libssh/misc.h" #include "libssh/pki.h" #include "libssh/pki_priv.h" #define MAXLINESIZE 80 #define RSA_HEADER_BEGIN "-----BEGIN RSA PRIVATE KEY-----" #define RSA_HEADER_END "-----END RSA PRIVATE KEY-----" #define DSA_HEADER_BEGIN "-----BEGIN DSA PRIVATE KEY-----" #define DSA_HEADER_END "-----END DSA PRIVATE KEY-----" #define MAX_KEY_SIZE 32 #define MAX_PASSPHRASE_SIZE 1024 #define ASN1_INTEGER 2 #define ASN1_SEQUENCE 48 #define PKCS5_SALT_LEN 8 static int load_iv(const char *header, unsigned char *iv, int iv_len) { int i; int j; int k; memset(iv, 0, iv_len); for (i = 0; i < iv_len; i++) { if ((header[2*i] >= '0') && (header[2*i] <= '9')) j = header[2*i] - '0'; else if ((header[2*i] >= 'A') && (header[2*i] <= 'F')) j = header[2*i] - 'A' + 10; else if ((header[2*i] >= 'a') && (header[2*i] <= 'f')) j = header[2*i] - 'a' + 10; else return -1; if ((header[2*i+1] >= '0') && (header[2*i+1] <= '9')) k = header[2*i+1] - '0'; else if ((header[2*i+1] >= 'A') && (header[2*i+1] <= 'F')) k = header[2*i+1] - 'A' + 10; else if ((header[2*i+1] >= 'a') && (header[2*i+1] <= 'f')) k = header[2*i+1] - 'a' + 10; else return -1; iv[i] = (j << 4) + k; } return 0; } static uint32_t char_to_u32(unsigned char *data, uint32_t size) { uint32_t ret; uint32_t i; for (i = 0, ret = 0; i < size; ret = ret << 8, ret += data[i++]) ; return ret; } static uint32_t asn1_get_len(ssh_buffer buffer) { uint32_t len; unsigned char tmp[4]; if (buffer_get_data(buffer,tmp,1) == 0) { return 0; } if (tmp[0] > 127) { len = tmp[0] & 127; if (len > 4) { return 0; /* Length doesn't fit in u32. Can this really happen? */ } if (buffer_get_data(buffer,tmp,len) == 0) { return 0; } len = char_to_u32(tmp, len); } else { len = char_to_u32(tmp, 1); } return len; } static ssh_string asn1_get_int(ssh_buffer buffer) { ssh_string str; unsigned char type; uint32_t size; if (buffer_get_data(buffer, &type, 1) == 0 || type != ASN1_INTEGER) { return NULL; } size = asn1_get_len(buffer); if (size == 0) { return NULL; } str = ssh_string_new(size); if (str == NULL) { return NULL; } if (buffer_get_data(buffer, ssh_string_data(str), size) == 0) { ssh_string_free(str); return NULL; } return str; } static int asn1_check_sequence(ssh_buffer buffer) { unsigned char *j = NULL; unsigned char tmp; int i; uint32_t size; uint32_t padding; if (buffer_get_data(buffer, &tmp, 1) == 0 || tmp != ASN1_SEQUENCE) { return 0; } size = asn1_get_len(buffer); if ((padding = ssh_buffer_get_len(buffer) - buffer->pos - size) > 0) { for (i = ssh_buffer_get_len(buffer) - buffer->pos - size, j = (unsigned char*)ssh_buffer_get_begin(buffer) + size + buffer->pos; i; i--, j++) { if (*j != padding) { /* padding is allowed */ return 0; /* but nothing else */ } } } return 1; } static int passphrase_to_key(char *data, unsigned int datalen, unsigned char *salt, unsigned char *key, unsigned int keylen) { MD5CTX md; unsigned char digest[MD5_DIGEST_LEN] = {0}; unsigned int i; unsigned int j; unsigned int md_not_empty; for (j = 0, md_not_empty = 0; j < keylen; ) { md = md5_init(); if (md == NULL) { return -1; } if (md_not_empty) { md5_update(md, digest, MD5_DIGEST_LEN); } else { md_not_empty = 1; } md5_update(md, data, datalen); if (salt) { md5_update(md, salt, PKCS5_SALT_LEN); } md5_final(digest, md); for (i = 0; j < keylen && i < MD5_DIGEST_LEN; j++, i++) { if (key) { key[j] = digest[i]; } } } return 0; } static int privatekey_decrypt(int algo, int mode, unsigned int key_len, unsigned char *iv, unsigned int iv_len, ssh_buffer data, ssh_auth_callback cb, void *userdata, const char *desc) { char passphrase[MAX_PASSPHRASE_SIZE] = {0}; unsigned char key[MAX_KEY_SIZE] = {0}; unsigned char *tmp = NULL; gcry_cipher_hd_t cipher; int rc = -1; if (!algo) { return -1; } if (cb) { rc = (*cb)(desc, passphrase, MAX_PASSPHRASE_SIZE, 0, 0, userdata); if (rc < 0) { return -1; } } else if (cb == NULL && userdata != NULL) { snprintf(passphrase, MAX_PASSPHRASE_SIZE, "%s", (char *) userdata); } if (passphrase_to_key(passphrase, strlen(passphrase), iv, key, key_len) < 0) { return -1; } if (gcry_cipher_open(&cipher, algo, mode, 0) || gcry_cipher_setkey(cipher, key, key_len) || gcry_cipher_setiv(cipher, iv, iv_len) || (tmp = malloc(ssh_buffer_get_len(data) * sizeof (char))) == NULL || gcry_cipher_decrypt(cipher, tmp, ssh_buffer_get_len(data), ssh_buffer_get_begin(data), ssh_buffer_get_len(data))) { gcry_cipher_close(cipher); return -1; } memcpy(ssh_buffer_get_begin(data), tmp, ssh_buffer_get_len(data)); SAFE_FREE(tmp); gcry_cipher_close(cipher); return 0; } static int privatekey_dek_header(const char *header, unsigned int header_len, int *algo, int *mode, unsigned int *key_len, unsigned char **iv, unsigned int *iv_len) { unsigned int iv_pos; if (header_len > 13 && !strncmp("DES-EDE3-CBC", header, 12)) { *algo = GCRY_CIPHER_3DES; iv_pos = 13; *mode = GCRY_CIPHER_MODE_CBC; *key_len = 24; *iv_len = 8; } else if (header_len > 8 && !strncmp("DES-CBC", header, 7)) { *algo = GCRY_CIPHER_DES; iv_pos = 8; *mode = GCRY_CIPHER_MODE_CBC; *key_len = 8; *iv_len = 8; } else if (header_len > 12 && !strncmp("AES-128-CBC", header, 11)) { *algo = GCRY_CIPHER_AES128; iv_pos = 12; *mode = GCRY_CIPHER_MODE_CBC; *key_len = 16; *iv_len = 16; } else if (header_len > 12 && !strncmp("AES-192-CBC", header, 11)) { *algo = GCRY_CIPHER_AES192; iv_pos = 12; *mode = GCRY_CIPHER_MODE_CBC; *key_len = 24; *iv_len = 16; } else if (header_len > 12 && !strncmp("AES-256-CBC", header, 11)) { *algo = GCRY_CIPHER_AES256; iv_pos = 12; *mode = GCRY_CIPHER_MODE_CBC; *key_len = 32; *iv_len = 16; } else { return -1; } *iv = malloc(*iv_len); if (*iv == NULL) { return -1; } return load_iv(header + iv_pos, *iv, *iv_len); } #define get_next_line(p, len) { \ while(p[len] == '\n' || p[len] == '\r') /* skip empty lines */ \ len++; \ if(p[len] == '\0') /* EOL */ \ len = -1; \ else /* calculate length */ \ for(p += len, len = 0; p[len] && p[len] != '\n' \ && p[len] != '\r'; len++); \ } static ssh_buffer privatekey_string_to_buffer(const char *pkey, int type, ssh_auth_callback cb, void *userdata, const char *desc) { ssh_buffer buffer = NULL; ssh_buffer out = NULL; const char *p; unsigned char *iv = NULL; const char *header_begin; const char *header_end; unsigned int header_begin_size; unsigned int header_end_size; unsigned int key_len = 0; unsigned int iv_len = 0; int algo = 0; int mode = 0; int len; buffer = ssh_buffer_new(); if (buffer == NULL) { return NULL; } switch(type) { case SSH_KEYTYPE_DSS: header_begin = DSA_HEADER_BEGIN; header_end = DSA_HEADER_END; break; case SSH_KEYTYPE_RSA: header_begin = RSA_HEADER_BEGIN; header_end = RSA_HEADER_END; break; default: ssh_buffer_free(buffer); return NULL; } header_begin_size = strlen(header_begin); header_end_size = strlen(header_end); p = pkey; len = 0; get_next_line(p, len); while(len > 0 && strncmp(p, header_begin, header_begin_size)) { /* skip line */ get_next_line(p, len); } if(len < 0) { /* no header found */ return NULL; } /* skip header line */ get_next_line(p, len); if (len > 11 && strncmp("Proc-Type: 4,ENCRYPTED", p, 11) == 0) { /* skip line */ get_next_line(p, len); if (len > 10 && strncmp("DEK-Info: ", p, 10) == 0) { p += 10; len = 0; get_next_line(p, len); if (privatekey_dek_header(p, len, &algo, &mode, &key_len, &iv, &iv_len) < 0) { ssh_buffer_free(buffer); SAFE_FREE(iv); return NULL; } } else { ssh_buffer_free(buffer); SAFE_FREE(iv); return NULL; } } else { if(len > 0) { if (ssh_buffer_add_data(buffer, p, len) < 0) { ssh_buffer_free(buffer); SAFE_FREE(iv); return NULL; } } } get_next_line(p, len); while(len > 0 && strncmp(p, header_end, header_end_size) != 0) { if (ssh_buffer_add_data(buffer, p, len) < 0) { ssh_buffer_free(buffer); SAFE_FREE(iv); return NULL; } get_next_line(p, len); } if (len == -1 || strncmp(p, header_end, header_end_size) != 0) { ssh_buffer_free(buffer); SAFE_FREE(iv); return NULL; } if (ssh_buffer_add_data(buffer, "\0", 1) < 0) { ssh_buffer_free(buffer); SAFE_FREE(iv); return NULL; } out = base64_to_bin(ssh_buffer_get_begin(buffer)); ssh_buffer_free(buffer); if (out == NULL) { SAFE_FREE(iv); return NULL; } if (algo) { if (privatekey_decrypt(algo, mode, key_len, iv, iv_len, out, cb, userdata, desc) < 0) { ssh_buffer_free(out); SAFE_FREE(iv); return NULL; } } SAFE_FREE(iv); return out; } static int b64decode_rsa_privatekey(const char *pkey, gcry_sexp_t *r, ssh_auth_callback cb, void *userdata, const char *desc) { const unsigned char *data; ssh_string n = NULL; ssh_string e = NULL; ssh_string d = NULL; ssh_string p = NULL; ssh_string q = NULL; ssh_string unused1 = NULL; ssh_string unused2 = NULL; ssh_string u = NULL; ssh_string v = NULL; ssh_buffer buffer = NULL; int rc = 1; buffer = privatekey_string_to_buffer(pkey, SSH_KEYTYPE_RSA, cb, userdata, desc); if (buffer == NULL) { return 0; } if (!asn1_check_sequence(buffer)) { ssh_buffer_free(buffer); return 0; } v = asn1_get_int(buffer); if (v == NULL) { ssh_buffer_free(buffer); return 0; } data = ssh_string_data(v); if (ssh_string_len(v) != 1 || data[0] != 0) { ssh_buffer_free(buffer); return 0; } n = asn1_get_int(buffer); e = asn1_get_int(buffer); d = asn1_get_int(buffer); q = asn1_get_int(buffer); p = asn1_get_int(buffer); unused1 = asn1_get_int(buffer); unused2 = asn1_get_int(buffer); u = asn1_get_int(buffer); ssh_buffer_free(buffer); if (n == NULL || e == NULL || d == NULL || p == NULL || q == NULL || unused1 == NULL || unused2 == NULL|| u == NULL) { rc = 0; goto error; } if (gcry_sexp_build(r, NULL, "(private-key(rsa(n %b)(e %b)(d %b)(p %b)(q %b)(u %b)))", ssh_string_len(n), ssh_string_data(n), ssh_string_len(e), ssh_string_data(e), ssh_string_len(d), ssh_string_data(d), ssh_string_len(p), ssh_string_data(p), ssh_string_len(q), ssh_string_data(q), ssh_string_len(u), ssh_string_data(u))) { rc = 0; } error: ssh_string_free(n); ssh_string_free(e); ssh_string_free(d); ssh_string_free(p); ssh_string_free(q); ssh_string_free(unused1); ssh_string_free(unused2); ssh_string_free(u); ssh_string_free(v); return rc; } static int b64decode_dsa_privatekey(const char *pkey, gcry_sexp_t *r, ssh_auth_callback cb, void *userdata, const char *desc) { const unsigned char *data; ssh_buffer buffer = NULL; ssh_string p = NULL; ssh_string q = NULL; ssh_string g = NULL; ssh_string y = NULL; ssh_string x = NULL; ssh_string v = NULL; int rc = 1; buffer = privatekey_string_to_buffer(pkey, SSH_KEYTYPE_DSS, cb, userdata, desc); if (buffer == NULL) { return 0; } if (!asn1_check_sequence(buffer)) { ssh_buffer_free(buffer); return 0; } v = asn1_get_int(buffer); if (v == NULL) { ssh_buffer_free(buffer); return 0; } data = ssh_string_data(v); if (ssh_string_len(v) != 1 || data[0] != 0) { ssh_buffer_free(buffer); return 0; } p = asn1_get_int(buffer); q = asn1_get_int(buffer); g = asn1_get_int(buffer); y = asn1_get_int(buffer); x = asn1_get_int(buffer); ssh_buffer_free(buffer); if (p == NULL || q == NULL || g == NULL || y == NULL || x == NULL) { rc = 0; goto error; } if (gcry_sexp_build(r, NULL, "(private-key(dsa(p %b)(q %b)(g %b)(y %b)(x %b)))", ssh_string_len(p), ssh_string_data(p), ssh_string_len(q), ssh_string_data(q), ssh_string_len(g), ssh_string_data(g), ssh_string_len(y), ssh_string_data(y), ssh_string_len(x), ssh_string_data(x))) { rc = 0; } error: ssh_string_free(p); ssh_string_free(q); ssh_string_free(g); ssh_string_free(y); ssh_string_free(x); ssh_string_free(v); return rc; } #ifdef HAVE_GCRYPT_ECC int pki_key_ecdsa_nid_from_name(const char *name) { return -1; } #endif ssh_string pki_private_key_to_pem(const ssh_key key, const char *passphrase, ssh_auth_callback auth_fn, void *auth_data) { (void) key; (void) passphrase; (void) auth_fn; (void) auth_data; return NULL; } ssh_key pki_private_key_from_base64(const char *b64_key, const char *passphrase, ssh_auth_callback auth_fn, void *auth_data) { gcry_sexp_t dsa = NULL; gcry_sexp_t rsa = NULL; ssh_key key = NULL; enum ssh_keytypes_e type; int valid; /* needed for gcrypt initialization */ if (ssh_init() < 0) { return NULL; } type = pki_privatekey_type_from_string(b64_key); if (type == SSH_KEYTYPE_UNKNOWN) { SSH_LOG(SSH_LOG_WARN, "Unknown or invalid private key."); return NULL; } switch (type) { case SSH_KEYTYPE_DSS: if (passphrase == NULL) { if (auth_fn) { valid = b64decode_dsa_privatekey(b64_key, &dsa, auth_fn, auth_data, "Passphrase for private key:"); } else { valid = b64decode_dsa_privatekey(b64_key, &dsa, NULL, NULL, NULL); } } else { valid = b64decode_dsa_privatekey(b64_key, &dsa, NULL, (void *) passphrase, NULL); } if (!valid) { SSH_LOG(SSH_LOG_WARN, "Parsing private key"); goto fail; } break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: if (passphrase == NULL) { if (auth_fn) { valid = b64decode_rsa_privatekey(b64_key, &rsa, auth_fn, auth_data, "Passphrase for private key:"); } else { valid = b64decode_rsa_privatekey(b64_key, &rsa, NULL, NULL, NULL); } } else { valid = b64decode_rsa_privatekey(b64_key, &rsa, NULL, (void *)passphrase, NULL); } if (!valid) { SSH_LOG(SSH_LOG_WARN, "Parsing private key"); goto fail; } break; case SSH_KEYTYPE_ED25519: /* Cannot open ed25519 keys with libgcrypt */ case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: default: SSH_LOG(SSH_LOG_WARN, "Unkown or invalid private key type %d", type); return NULL; } key = ssh_key_new(); if (key == NULL) { goto fail; } key->type = type; key->type_c = ssh_key_type_to_char(type); key->flags = SSH_KEY_FLAG_PRIVATE | SSH_KEY_FLAG_PUBLIC; key->dsa = dsa; key->rsa = rsa; return key; fail: ssh_key_free(key); gcry_sexp_release(dsa); gcry_sexp_release(rsa); return NULL; } int pki_pubkey_build_dss(ssh_key key, ssh_string p, ssh_string q, ssh_string g, ssh_string pubkey) { gcry_sexp_build(&key->dsa, NULL, "(public-key(dsa(p %b)(q %b)(g %b)(y %b)))", ssh_string_len(p), ssh_string_data(p), ssh_string_len(q), ssh_string_data(q), ssh_string_len(g), ssh_string_data(g), ssh_string_len(pubkey), ssh_string_data(pubkey)); if (key->dsa == NULL) { return SSH_ERROR; } return SSH_OK; } int pki_pubkey_build_rsa(ssh_key key, ssh_string e, ssh_string n) { gcry_sexp_build(&key->rsa, NULL, "(public-key(rsa(n %b)(e %b)))", ssh_string_len(n), ssh_string_data(n), ssh_string_len(e),ssh_string_data(e)); if (key->rsa == NULL) { return SSH_ERROR; } return SSH_OK; } #ifdef HAVE_GCRYPT_ECC int pki_pubkey_build_ecdsa(ssh_key key, int nid, ssh_string e) { return -1; } #endif ssh_key pki_key_dup(const ssh_key key, int demote) { ssh_key new; gcry_sexp_t sexp; gcry_error_t err; const char *tmp = NULL; size_t size; int rc; ssh_string p = NULL; ssh_string q = NULL; ssh_string g = NULL; ssh_string y = NULL; ssh_string x = NULL; ssh_string e = NULL; ssh_string n = NULL; ssh_string d = NULL; ssh_string u = NULL; new = ssh_key_new(); if (new == NULL) { return NULL; } new->type = key->type; new->type_c = key->type_c; if (demote) { new->flags = SSH_KEY_FLAG_PUBLIC; } else { new->flags = key->flags; } switch(key->type) { case SSH_KEYTYPE_DSS: sexp = gcry_sexp_find_token(key->dsa, "p", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); p = ssh_string_new(size); if (p == NULL) { goto fail; } ssh_string_fill(p, (char *)tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->dsa, "q", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); q = ssh_string_new(size); if (q == NULL) { goto fail; } ssh_string_fill(q, (char *)tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->dsa, "g", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); g = ssh_string_new(size); if (g == NULL) { goto fail; } ssh_string_fill(g, (char *)tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->dsa, "y", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); y = ssh_string_new(size); if (y == NULL) { goto fail; } ssh_string_fill(y, (char *)tmp, size); gcry_sexp_release(sexp); if (!demote && (key->flags & SSH_KEY_FLAG_PRIVATE)) { sexp = gcry_sexp_find_token(key->dsa, "x", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); x = ssh_string_new(size); if (x == NULL) { goto fail; } ssh_string_fill(x, (char *)tmp, size); gcry_sexp_release(sexp); err = gcry_sexp_build(&new->dsa, NULL, "(private-key(dsa(p %b)(q %b)(g %b)(y %b)(x %b)))", ssh_string_len(p), ssh_string_data(p), ssh_string_len(q), ssh_string_data(q), ssh_string_len(g), ssh_string_data(g), ssh_string_len(y), ssh_string_data(y), ssh_string_len(x), ssh_string_data(x)); } else { err = gcry_sexp_build(&new->dsa, NULL, "(public-key(dsa(p %b)(q %b)(g %b)(y %b)))", ssh_string_len(p), ssh_string_data(p), ssh_string_len(q), ssh_string_data(q), ssh_string_len(g), ssh_string_data(g), ssh_string_len(y), ssh_string_data(y)); } if (err) { goto fail; } ssh_string_burn(p); ssh_string_free(p); ssh_string_burn(q); ssh_string_free(q); ssh_string_burn(g); ssh_string_free(g); ssh_string_burn(y); ssh_string_free(y); ssh_string_burn(x); ssh_string_free(x); break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: sexp = gcry_sexp_find_token(key->rsa, "e", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); e = ssh_string_new(size); if (e == NULL) { goto fail; } ssh_string_fill(e, (char *)tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->rsa, "n", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); n = ssh_string_new(size); if (n == NULL) { goto fail; } ssh_string_fill(n, (char *)tmp, size); gcry_sexp_release(sexp); if (!demote && (key->flags & SSH_KEY_FLAG_PRIVATE)) { sexp = gcry_sexp_find_token(key->rsa, "d", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); d = ssh_string_new(size); if (e == NULL) { goto fail; } ssh_string_fill(d, (char *)tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->rsa, "p", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); p = ssh_string_new(size); if (p == NULL) { goto fail; } ssh_string_fill(p, (char *)tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->rsa, "q", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); q = ssh_string_new(size); if (q == NULL) { goto fail; } ssh_string_fill(q, (char *)tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->rsa, "u", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); u = ssh_string_new(size); if (u == NULL) { goto fail; } ssh_string_fill(u, (char *)tmp, size); gcry_sexp_release(sexp); err = gcry_sexp_build(&new->rsa, NULL, "(private-key(rsa(n %b)(e %b)(d %b)(p %b)(q %b)(u %b)))", ssh_string_len(n), ssh_string_data(n), ssh_string_len(e), ssh_string_data(e), ssh_string_len(d), ssh_string_data(d), ssh_string_len(p), ssh_string_data(p), ssh_string_len(q), ssh_string_data(q), ssh_string_len(u), ssh_string_data(u)); } else { err = gcry_sexp_build(&new->rsa, NULL, "(public-key(rsa(n %b)(e %b)))", ssh_string_len(n), ssh_string_data(n), ssh_string_len(e), ssh_string_data(e)); } if (err) { goto fail; } ssh_string_burn(e); ssh_string_free(e); ssh_string_burn(n); ssh_string_free(n); ssh_string_burn(d); ssh_string_free(d); ssh_string_burn(p); ssh_string_free(p); ssh_string_burn(q); ssh_string_free(q); ssh_string_burn(u); ssh_string_free(u); break; case SSH_KEYTYPE_ED25519: rc = pki_ed25519_key_dup(new, key); if (rc != SSH_OK){ goto fail; } break; case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: default: ssh_key_free(new); return NULL; } return new; fail: gcry_sexp_release(sexp); ssh_string_burn(p); ssh_string_free(p); ssh_string_burn(q); ssh_string_free(q); ssh_string_burn(g); ssh_string_free(g); ssh_string_burn(y); ssh_string_free(y); ssh_string_burn(x); ssh_string_free(x); ssh_string_burn(e); ssh_string_free(e); ssh_string_burn(n); ssh_string_free(n); ssh_string_burn(u); ssh_string_free(u); ssh_key_free(new); return NULL; } static int pki_key_generate(ssh_key key, int parameter, const char *type_s, int type){ gcry_sexp_t parms; int rc; rc = gcry_sexp_build(&parms, NULL, "(genkey(%s(nbits %d)(transient-key)))", type_s, parameter); if (rc != 0) return SSH_ERROR; if(type == SSH_KEYTYPE_RSA) rc = gcry_pk_genkey(&key->rsa, parms); else rc = gcry_pk_genkey(&key->dsa, parms); gcry_sexp_release(parms); if (rc != 0) return SSH_ERROR; return SSH_OK; } int pki_key_generate_rsa(ssh_key key, int parameter){ return pki_key_generate(key, parameter, "rsa", SSH_KEYTYPE_RSA); } int pki_key_generate_dss(ssh_key key, int parameter){ return pki_key_generate(key, parameter, "dsa", SSH_KEYTYPE_DSS); } #ifdef HAVE_GCRYPT_ECC int pki_key_generate_ecdsa(ssh_key key, int parameter) { return -1; } #endif static int _bignum_cmp(const gcry_sexp_t s1, const gcry_sexp_t s2, const char *what) { gcry_sexp_t sexp; bignum b1; bignum b2; sexp = gcry_sexp_find_token(s1, what, 0); if (sexp == NULL) { return 1; } b1 = gcry_sexp_nth_mpi(sexp, 1, GCRYMPI_FMT_USG); gcry_sexp_release(sexp); if (b1 == NULL) { return 1; } sexp = gcry_sexp_find_token(s2, what, 0); if (sexp == NULL) { return 1; } b2 = gcry_sexp_nth_mpi(sexp, 1, GCRYMPI_FMT_USG); gcry_sexp_release(sexp); if (b2 == NULL) { return 1; } if (bignum_cmp(b1, b2) != 0) { return 1; } return 0; } int pki_key_compare(const ssh_key k1, const ssh_key k2, enum ssh_keycmp_e what) { switch (k1->type) { case SSH_KEYTYPE_DSS: if (_bignum_cmp(k1->dsa, k2->dsa, "p") != 0) { return 1; } if (_bignum_cmp(k1->dsa, k2->dsa, "q") != 0) { return 1; } if (_bignum_cmp(k1->dsa, k2->dsa, "g") != 0) { return 1; } if (_bignum_cmp(k1->dsa, k2->dsa, "y") != 0) { return 1; } if (what == SSH_KEY_CMP_PRIVATE) { if (_bignum_cmp(k1->dsa, k2->dsa, "x") != 0) { return 1; } } break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: if (_bignum_cmp(k1->rsa, k2->rsa, "e") != 0) { return 1; } if (_bignum_cmp(k1->rsa, k2->rsa, "n") != 0) { return 1; } if (what == SSH_KEY_CMP_PRIVATE) { if (_bignum_cmp(k1->rsa, k2->rsa, "d") != 0) { return 1; } if (_bignum_cmp(k1->rsa, k2->rsa, "p") != 0) { return 1; } if (_bignum_cmp(k1->rsa, k2->rsa, "q") != 0) { return 1; } if (_bignum_cmp(k1->rsa, k2->rsa, "u") != 0) { return 1; } } break; case SSH_KEYTYPE_ED25519: /* ed25519 keys handled globaly */ return 0; case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: return 1; } return 0; } ssh_string pki_publickey_to_blob(const ssh_key key) { ssh_buffer buffer; ssh_string type_s; ssh_string str = NULL; ssh_string e = NULL; ssh_string n = NULL; ssh_string p = NULL; ssh_string g = NULL; ssh_string q = NULL; const char *tmp = NULL; size_t size; gcry_sexp_t sexp; int rc; buffer = ssh_buffer_new(); if (buffer == NULL) { return NULL; } type_s = ssh_string_from_char(key->type_c); if (type_s == NULL) { ssh_buffer_free(buffer); return NULL; } rc = buffer_add_ssh_string(buffer, type_s); ssh_string_free(type_s); if (rc < 0) { ssh_buffer_free(buffer); return NULL; } switch (key->type) { case SSH_KEYTYPE_DSS: sexp = gcry_sexp_find_token(key->dsa, "p", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); p = ssh_string_new(size); if (p == NULL) { goto fail; } ssh_string_fill(p, (char *) tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->dsa, "q", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); q = ssh_string_new(size); if (q == NULL) { goto fail; } ssh_string_fill(q, (char *) tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->dsa, "g", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); g = ssh_string_new(size); if (g == NULL) { goto fail; } ssh_string_fill(g, (char *) tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->dsa, "y", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); n = ssh_string_new(size); if (n == NULL) { goto fail; } ssh_string_fill(n, (char *) tmp, size); if (buffer_add_ssh_string(buffer, p) < 0) { goto fail; } if (buffer_add_ssh_string(buffer, q) < 0) { goto fail; } if (buffer_add_ssh_string(buffer, g) < 0) { goto fail; } if (buffer_add_ssh_string(buffer, n) < 0) { goto fail; } ssh_string_burn(p); ssh_string_free(p); ssh_string_burn(g); ssh_string_free(g); ssh_string_burn(q); ssh_string_free(q); ssh_string_burn(n); ssh_string_free(n); break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: sexp = gcry_sexp_find_token(key->rsa, "e", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); e = ssh_string_new(size); if (e == NULL) { goto fail; } ssh_string_fill(e, (char *) tmp, size); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(key->rsa, "n", 0); if (sexp == NULL) { goto fail; } tmp = gcry_sexp_nth_data(sexp, 1, &size); n = ssh_string_new(size); if (n == NULL) { goto fail; } ssh_string_fill(n, (char *) tmp, size); gcry_sexp_release(sexp); if (buffer_add_ssh_string(buffer, e) < 0) { goto fail; } if (buffer_add_ssh_string(buffer, n) < 0) { goto fail; } ssh_string_burn(e); ssh_string_free(e); ssh_string_burn(n); ssh_string_free(n); break; case SSH_KEYTYPE_ED25519: rc = pki_ed25519_public_key_to_blob(buffer, key); if (rc != SSH_OK){ goto fail; } break; case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: default: goto fail; } str = ssh_string_new(buffer_get_rest_len(buffer)); if (str == NULL) { goto fail; } rc = ssh_string_fill(str, buffer_get_rest(buffer), buffer_get_rest_len(buffer)); if (rc < 0) { goto fail; } ssh_buffer_free(buffer); return str; fail: ssh_buffer_free(buffer); ssh_string_burn(str); ssh_string_free(str); ssh_string_burn(e); ssh_string_free(e); ssh_string_burn(p); ssh_string_free(p); ssh_string_burn(g); ssh_string_free(g); ssh_string_burn(q); ssh_string_free(q); ssh_string_burn(n); ssh_string_free(n); return NULL; } int pki_export_pubkey_rsa1(const ssh_key key, const char *host, char *rsa1, size_t rsa1_len) { gcry_sexp_t sexp; int rsa_size; bignum b; char *e, *n; sexp = gcry_sexp_find_token(key->rsa, "e", 0); if (sexp == NULL) { return SSH_ERROR; } b = gcry_sexp_nth_mpi(sexp, 1, GCRYMPI_FMT_USG); gcry_sexp_release(sexp); if (b == NULL) { return SSH_ERROR; } e = bignum_bn2dec(b); sexp = gcry_sexp_find_token(key->rsa, "n", 0); if (sexp == NULL) { SAFE_FREE(e); return SSH_ERROR; } b = gcry_sexp_nth_mpi(sexp, 1, GCRYMPI_FMT_USG); gcry_sexp_release(sexp); if (b == NULL) { SAFE_FREE(e); return SSH_ERROR; } n = bignum_bn2dec(b); rsa_size = (gcry_pk_get_nbits(key->rsa) + 7) / 8; snprintf(rsa1, rsa1_len, "%s %d %s %s\n", host, rsa_size << 3, e, n); SAFE_FREE(e); SAFE_FREE(n); return SSH_OK; } ssh_string pki_signature_to_blob(const ssh_signature sig) { char buffer[40] = { 0 }; const char *r = NULL; size_t r_len, r_offset_in, r_offset_out; const char *s = NULL; size_t s_len, s_offset_in, s_offset_out; gcry_sexp_t sexp; size_t size = 0; ssh_string sig_blob = NULL; switch(sig->type) { case SSH_KEYTYPE_DSS: sexp = gcry_sexp_find_token(sig->dsa_sig, "r", 0); if (sexp == NULL) { return NULL; } r = gcry_sexp_nth_data(sexp, 1, &size); /* libgcrypt put 0 when first bit is set */ if (*r == 0) { size--; r++; } r_len = size; r_offset_in = (r_len > 20) ? (r_len - 20) : 0; r_offset_out = (r_len < 20) ? (20 - r_len) : 0; memcpy(buffer + r_offset_out, r + r_offset_in, r_len - r_offset_in); gcry_sexp_release(sexp); sexp = gcry_sexp_find_token(sig->dsa_sig, "s", 0); if (sexp == NULL) { return NULL; } s = gcry_sexp_nth_data(sexp,1,&size); if (*s == 0) { size--; s++; } s_len = size; s_offset_in = (s_len > 20) ? (s_len - 20) : 0; s_offset_out = (s_len < 20) ? (20 - s_len) : 0; memcpy(buffer + 20 + s_offset_out, s + s_offset_in, s_len - s_offset_in); gcry_sexp_release(sexp); sig_blob = ssh_string_new(40); if (sig_blob == NULL) { return NULL; } ssh_string_fill(sig_blob, buffer, 40); break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: sexp = gcry_sexp_find_token(sig->rsa_sig, "s", 0); if (sexp == NULL) { return NULL; } s = gcry_sexp_nth_data(sexp, 1, &size); if (*s == 0) { size--; s++; } sig_blob = ssh_string_new(size); if (sig_blob == NULL) { return NULL; } ssh_string_fill(sig_blob, discard_const_p(char, s), size); gcry_sexp_release(sexp); break; case SSH_KEYTYPE_ED25519: sig_blob = pki_ed25519_sig_to_blob(sig); break; case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: default: SSH_LOG(SSH_LOG_WARN, "Unknown signature key type: %d", sig->type); return NULL; break; } return sig_blob; } ssh_signature pki_signature_from_blob(const ssh_key pubkey, const ssh_string sig_blob, enum ssh_keytypes_e type) { ssh_signature sig; gcry_error_t err; size_t len; size_t rsalen; int rc; sig = ssh_signature_new(); if (sig == NULL) { return NULL; } sig->type = type; len = ssh_string_len(sig_blob); switch(type) { case SSH_KEYTYPE_DSS: /* 40 is the dual signature blob len. */ if (len != 40) { SSH_LOG(SSH_LOG_WARN, "Signature has wrong size: %lu", (unsigned long)len); ssh_signature_free(sig); return NULL; } #ifdef DEBUG_CRYPTO SSH_LOG(SSH_LOG_DEBUG, "DSA signature len: %lu", (unsigned long)len); ssh_print_hexa("DSA signature", ssh_string_data(sig_blob), len); #endif err = gcry_sexp_build(&sig->dsa_sig, NULL, "(sig-val(dsa(r %b)(s %b)))", 20, ssh_string_data(sig_blob), 20, (unsigned char *)ssh_string_data(sig_blob) + 20); if (err) { ssh_signature_free(sig); return NULL; } break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: rsalen = (gcry_pk_get_nbits(pubkey->rsa) + 7) / 8; if (len > rsalen) { SSH_LOG(SSH_LOG_WARN, "Signature is to big size: %lu", (unsigned long)len); ssh_signature_free(sig); return NULL; } if (len < rsalen) { SSH_LOG(SSH_LOG_DEBUG, "RSA signature len %lu < %lu", (unsigned long)len, (unsigned long)rsalen); } #ifdef DEBUG_CRYPTO SSH_LOG(SSH_LOG_DEBUG, "RSA signature len: %lu", (unsigned long)len); ssh_print_hexa("RSA signature", ssh_string_data(sig_blob), len); #endif err = gcry_sexp_build(&sig->rsa_sig, NULL, "(sig-val(rsa(s %b)))", ssh_string_len(sig_blob), ssh_string_data(sig_blob)); if (err) { ssh_signature_free(sig); return NULL; } break; case SSH_KEYTYPE_ED25519: rc = pki_ed25519_sig_from_blob(sig, sig_blob); if (rc != SSH_OK){ ssh_signature_free(sig); return NULL; } break; case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: default: SSH_LOG(SSH_LOG_WARN, "Unknown signature type"); return NULL; } return sig; } int pki_signature_verify(ssh_session session, const ssh_signature sig, const ssh_key key, const unsigned char *hash, size_t hlen) { unsigned char ghash[hlen + 1]; gcry_sexp_t sexp; gcry_error_t err; switch(key->type) { case SSH_KEYTYPE_DSS: /* That is to mark the number as positive */ if(hash[0] >= 0x80) { memcpy(ghash + 1, hash, hlen); ghash[0] = 0; hash = ghash; hlen += 1; } err = gcry_sexp_build(&sexp, NULL, "%b", hlen, hash); if (err) { ssh_set_error(session, SSH_FATAL, "DSA hash error: %s", gcry_strerror(err)); return SSH_ERROR; } err = gcry_pk_verify(sig->dsa_sig, sexp, key->dsa); gcry_sexp_release(sexp); if (err) { ssh_set_error(session, SSH_FATAL, "Invalid DSA signature"); if (gcry_err_code(err) != GPG_ERR_BAD_SIGNATURE) { ssh_set_error(session, SSH_FATAL, "DSA verify error: %s", gcry_strerror(err)); } return SSH_ERROR; } break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: err = gcry_sexp_build(&sexp, NULL, "(data(flags pkcs1)(hash sha1 %b))", hlen, hash); if (err) { ssh_set_error(session, SSH_FATAL, "RSA hash error: %s", gcry_strerror(err)); return SSH_ERROR; } err = gcry_pk_verify(sig->rsa_sig, sexp, key->rsa); gcry_sexp_release(sexp); if (err) { ssh_set_error(session, SSH_FATAL, "Invalid RSA signature"); if (gcry_err_code(err) != GPG_ERR_BAD_SIGNATURE) { ssh_set_error(session, SSH_FATAL, "RSA verify error: %s", gcry_strerror(err)); } return SSH_ERROR; } break; case SSH_KEYTYPE_ED25519: err = pki_ed25519_verify(key, sig, hash, hlen); if (err != SSH_OK){ ssh_set_error(session, SSH_FATAL, "ed25519 signature verification error"); return SSH_ERROR; } break; case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: default: ssh_set_error(session, SSH_FATAL, "Unknown public key type"); return SSH_ERROR; } return SSH_OK; } ssh_signature pki_do_sign(const ssh_key privkey, const unsigned char *hash, size_t hlen) { unsigned char ghash[hlen + 1]; ssh_signature sig; gcry_sexp_t sexp; gcry_error_t err; sig = ssh_signature_new(); if (sig == NULL) { return NULL; } sig->type = privkey->type; sig->type_c = privkey->type_c; switch (privkey->type) { case SSH_KEYTYPE_DSS: /* That is to mark the number as positive */ if(hash[0] >= 0x80) { memcpy(ghash + 1, hash, hlen); ghash[0] = 0; hash = ghash; hlen += 1; } err = gcry_sexp_build(&sexp, NULL, "%b", hlen, hash); if (err) { ssh_signature_free(sig); return NULL; } err = gcry_pk_sign(&sig->dsa_sig, sexp, privkey->dsa); gcry_sexp_release(sexp); if (err) { ssh_signature_free(sig); return NULL; } break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: err = gcry_sexp_build(&sexp, NULL, "(data(flags pkcs1)(hash sha1 %b))", hlen, hash); if (err) { ssh_signature_free(sig); return NULL; } err = gcry_pk_sign(&sig->rsa_sig, sexp, privkey->rsa); gcry_sexp_release(sexp); if (err) { ssh_signature_free(sig); return NULL; } break; case SSH_KEYTYPE_ED25519: err = pki_ed25519_sign(privkey, sig, hash, hlen); if (err != SSH_OK){ ssh_signature_free(sig); return NULL; } break; case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: default: ssh_signature_free(sig); return NULL; } return sig; } #ifdef WITH_SERVER ssh_signature pki_do_sign_sessionid(const ssh_key key, const unsigned char *hash, size_t hlen) { unsigned char ghash[hlen + 1]; ssh_signature sig; gcry_sexp_t sexp; gcry_error_t err; sig = ssh_signature_new(); if (sig == NULL) { return NULL; } sig->type = key->type; sig->type_c = key->type_c; switch(key->type) { case SSH_KEYTYPE_DSS: /* That is to mark the number as positive */ if(hash[0] >= 0x80) { memcpy(ghash + 1, hash, hlen); ghash[0] = 0; hash = ghash; hlen += 1; } err = gcry_sexp_build(&sexp, NULL, "%b", hlen, hash); if (err) { ssh_signature_free(sig); return NULL; } err = gcry_pk_sign(&sig->dsa_sig, sexp, key->dsa); gcry_sexp_release(sexp); if (err) { ssh_signature_free(sig); return NULL; } break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: err = gcry_sexp_build(&sexp, NULL, "(data(flags pkcs1)(hash sha1 %b))", hlen, hash); if (err) { ssh_signature_free(sig); return NULL; } err = gcry_pk_sign(&sig->rsa_sig, sexp, key->rsa); gcry_sexp_release(sexp); if (err) { ssh_signature_free(sig); return NULL; } break; case SSH_KEYTYPE_ED25519: /* ED25519 handled in caller */ case SSH_KEYTYPE_ECDSA: case SSH_KEYTYPE_UNKNOWN: default: return NULL; } return sig; } #endif /* WITH_SERVER */ #endif /* HAVE_LIBGCRYPT */ /* vim: set ts=4 sw=4 et cindent: */