+Bignum biggcd(Bignum a, Bignum b);
+unsigned short bignum_mod_short(Bignum number, unsigned short modulus);
+Bignum bignum_add_long(Bignum number, unsigned long addend);
+Bignum bigmul(Bignum a, Bignum b);
+Bignum bigmuladd(Bignum a, Bignum b, Bignum addend);
+Bignum bigdiv(Bignum a, Bignum b);
+Bignum bigmod(Bignum a, Bignum b);
+Bignum modinv(Bignum number, Bignum modulus);
+Bignum bignum_bitmask(Bignum number);
+Bignum bignum_rshift(Bignum number, int shift);
+int bignum_cmp(Bignum a, Bignum b);
+char *bignum_decimal(Bignum x);
+
+#ifdef DEBUG
+void diagbn(char *prefix, Bignum md);
+#endif
+
+void *dh_setup_group(const struct ssh_kex *kex);
+void *dh_setup_gex(Bignum pval, Bignum gval);
+void dh_cleanup(void *);
+Bignum dh_create_e(void *, int nbits);
+Bignum dh_find_K(void *, Bignum f);
+
+int loadrsakey(const Filename *filename, struct RSAKey *key,
+ char *passphrase, const char **errorstr);
+int rsakey_encrypted(const Filename *filename, char **comment);
+int rsakey_pubblob(const Filename *filename, void **blob, int *bloblen,
+ const char **errorstr);
+
+int saversakey(const Filename *filename, struct RSAKey *key, char *passphrase);
+
+extern int base64_decode_atom(char *atom, unsigned char *out);
+extern int base64_lines(int datalen);
+extern void base64_encode_atom(unsigned char *data, int n, char *out);
+extern void base64_encode(FILE *fp, unsigned char *data, int datalen, int cpl);
+
+/* ssh2_load_userkey can return this as an error */
+extern struct ssh2_userkey ssh2_wrong_passphrase;
+#define SSH2_WRONG_PASSPHRASE (&ssh2_wrong_passphrase)
+
+int ssh2_userkey_encrypted(const Filename *filename, char **comment);
+struct ssh2_userkey *ssh2_load_userkey(const Filename *filename,
+ char *passphrase, const char **errorstr);
+char *ssh2_userkey_loadpub(const Filename *filename, char **algorithm,
+ int *pub_blob_len, const char **errorstr);
+int ssh2_save_userkey(const Filename *filename, struct ssh2_userkey *key,
+ char *passphrase);
+const struct ssh_signkey *find_pubkey_alg(const char *name);
+
+enum {
+ SSH_KEYTYPE_UNOPENABLE,
+ SSH_KEYTYPE_UNKNOWN,
+ SSH_KEYTYPE_SSH1, SSH_KEYTYPE_SSH2,
+ SSH_KEYTYPE_OPENSSH, SSH_KEYTYPE_SSHCOM
+};
+int key_type(const Filename *filename);
+char *key_type_to_str(int type);
+
+int import_possible(int type);
+int import_target_type(int type);
+int import_encrypted(const Filename *filename, int type, char **comment);
+int import_ssh1(const Filename *filename, int type,
+ struct RSAKey *key, char *passphrase);
+struct ssh2_userkey *import_ssh2(const Filename *filename, int type,
+ char *passphrase);
+int export_ssh1(const Filename *filename, int type,
+ struct RSAKey *key, char *passphrase);
+int export_ssh2(const Filename *filename, int type,
+ struct ssh2_userkey *key, char *passphrase);
+
+void des3_decrypt_pubkey(unsigned char *key, unsigned char *blk, int len);
+void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len);
+void des3_decrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
+ unsigned char *blk, int len);
+void des3_encrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
+ unsigned char *blk, int len);
+void aes256_encrypt_pubkey(unsigned char *key, unsigned char *blk,
+ int len);
+void aes256_decrypt_pubkey(unsigned char *key, unsigned char *blk,
+ int len);
+
+void des_encrypt_xdmauth(unsigned char *key, unsigned char *blk, int len);
+void des_decrypt_xdmauth(unsigned char *key, unsigned char *blk, int len);
+
+/*
+ * For progress updates in the key generation utility.
+ */
+#define PROGFN_INITIALISE 1
+#define PROGFN_LIN_PHASE 2
+#define PROGFN_EXP_PHASE 3
+#define PROGFN_PHASE_EXTENT 4
+#define PROGFN_READY 5
+#define PROGFN_PROGRESS 6
+typedef void (*progfn_t) (void *param, int action, int phase, int progress);
+
+int rsa_generate(struct RSAKey *key, int bits, progfn_t pfn,
+ void *pfnparam);
+int dsa_generate(struct dss_key *key, int bits, progfn_t pfn,
+ void *pfnparam);
+Bignum primegen(int bits, int modulus, int residue, Bignum factor,
+ int phase, progfn_t pfn, void *pfnparam);
+
+
+/*
+ * zlib compression.
+ */
+void *zlib_compress_init(void);
+void zlib_compress_cleanup(void *);
+void *zlib_decompress_init(void);
+void zlib_decompress_cleanup(void *);
+int zlib_compress_block(void *, unsigned char *block, int len,
+ unsigned char **outblock, int *outlen);
+int zlib_decompress_block(void *, unsigned char *block, int len,
+ unsigned char **outblock, int *outlen);
+
+/*
+ * SSH1 agent messages.
+ */
+#define SSH1_AGENTC_REQUEST_RSA_IDENTITIES 1
+#define SSH1_AGENT_RSA_IDENTITIES_ANSWER 2
+#define SSH1_AGENTC_RSA_CHALLENGE 3
+#define SSH1_AGENT_RSA_RESPONSE 4
+#define SSH1_AGENTC_ADD_RSA_IDENTITY 7
+#define SSH1_AGENTC_REMOVE_RSA_IDENTITY 8
+#define SSH1_AGENTC_REMOVE_ALL_RSA_IDENTITIES 9 /* openssh private? */