diff options
Diffstat (limited to 'common/openpgp-oid.c')
| -rw-r--r-- | common/openpgp-oid.c | 165 |
1 files changed, 162 insertions, 3 deletions
diff --git a/common/openpgp-oid.c b/common/openpgp-oid.c index 943fe3ea6..9d8b2d351 100644 --- a/common/openpgp-oid.c +++ b/common/openpgp-oid.c @@ -71,6 +71,21 @@ static const char oid_ed25519[] = static const char oid_cv25519[] = { 0x0a, 0x2b, 0x06, 0x01, 0x04, 0x01, 0x97, 0x55, 0x01, 0x05, 0x01 }; +/* A table to store keyalgo strings like "rsa2048 or "ed25519" so that + * we do not need to allocate them. This is currently a simple array + * but may eventually be changed to a fast data structure. Noet that + * unknown algorithms are stored with (NBITS,CURVE) set to (0,NULL). */ +struct keyalgo_string_s +{ + enum gcry_pk_algos algo; /* Mandatory. */ + unsigned int nbits; /* Size for classical algos. */ + char *curve; /* Curvename (OID) or NULL. */ + char *name; /* Allocated name. */ +}; +static struct keyalgo_string_s *keyalgo_strings; /* The table. */ +static size_t keyalgo_strings_size; /* Allocated size. */ +static size_t keyalgo_strings_used; /* Used size. */ + /* Helper for openpgp_oid_from_str. */ static size_t @@ -383,9 +398,9 @@ openpgp_curve_to_oid (const char *name, unsigned int *r_nbits, int *r_algo) } -/* Map an OpenPGP OID to the Libgcrypt curve NAME. Returns NULL for - unknown curve names. Unless CANON is set we prefer an alias name - here which is more suitable for printing. */ +/* Map an OpenPGP OID to the Libgcrypt curve name. Returns NULL for + * unknown curve names. Unless CANON is set we prefer an alias name + * here which is more suitable for printing. */ const char * openpgp_oid_to_curve (const char *oidstr, int canon) { @@ -402,6 +417,27 @@ openpgp_oid_to_curve (const char *oidstr, int canon) } +/* Map an OpenPGP OID, name or alias to the Libgcrypt curve name. + * Returns NULL for unknown curve names. Unless CANON is set we + * prefer an alias name here which is more suitable for printing. */ +const char * +openpgp_oid_or_name_to_curve (const char *oidname, int canon) +{ + int i; + + if (!oidname) + return NULL; + + for (i=0; oidtable[i].name; i++) + if (!strcmp (oidtable[i].oidstr, oidname) + || !strcmp (oidtable[i].name, oidname) + || (oidtable[i].alias &&!strcmp (oidtable[i].alias, oidname))) + return !canon && oidtable[i].alias? oidtable[i].alias : oidtable[i].name; + + return NULL; +} + + /* Return true if the curve with NAME is supported. */ static int curve_supported_p (const char *name) @@ -470,3 +506,126 @@ openpgp_is_curve_supported (const char *name, int *r_algo, } return NULL; } + + +/* Map an OpenPGP public key algorithm number to the one used by + * Libgcrypt. Returns 0 for unknown gcry algorithm. */ +enum gcry_pk_algos +map_openpgp_pk_to_gcry (pubkey_algo_t algo) +{ + switch (algo) + { + case PUBKEY_ALGO_EDDSA: return GCRY_PK_EDDSA; + case PUBKEY_ALGO_ECDSA: return GCRY_PK_ECDSA; + case PUBKEY_ALGO_ECDH: return GCRY_PK_ECDH; + default: return algo < 110 ? (enum gcry_pk_algos)algo : 0; + } +} + + +/* Return a string describing the public key algorithm and the + * keysize. For elliptic curves the function prints the name of the + * curve because the keysize is a property of the curve. ALGO is the + * Gcrypt algorithmj number, curve is either NULL or give the PID of + * the curve, NBITS is either 0 or the size of the algorithms for RSA + * etc. The returned string is taken from permanent table. Examples + * for the output are: + * + * "rsa3072" - RSA with 3072 bit + * "elg1024" - Elgamal with 1024 bit + * "ed25519" - ECC using the curve Ed25519. + * "E_1.2.3.4" - ECC using the unsupported curve with OID "1.2.3.4". + * "E_1.3.6.1.4.1.11591.2.12242973" - ECC with a bogus OID. + * "unknown_N" - Unknown OpenPGP algorithm N. + * If N is > 110 this is a gcrypt algo. + */ +const char * +get_keyalgo_string (enum gcry_pk_algos algo, + unsigned int nbits, const char *curve) +{ + const char *prefix; + int i; + char *name, *curvebuf; + + switch (algo) + { + case GCRY_PK_RSA: prefix = "rsa"; break; + case GCRY_PK_ELG: prefix = "elg"; break; + case GCRY_PK_DSA: prefix = "dsa"; break; + case GCRY_PK_ECC: + case GCRY_PK_ECDH: + case GCRY_PK_ECDSA: + case GCRY_PK_EDDSA: prefix = ""; break; + default: prefix = NULL; break; + } + + if (prefix && *prefix && nbits) + { + for (i=0; i < keyalgo_strings_used; i++) + { + if (keyalgo_strings[i].algo == algo + && keyalgo_strings[i].nbits + && keyalgo_strings[i].nbits == nbits) + return keyalgo_strings[i].name; + } + /* Not yet in the table - add it. */ + name = xasprintf ("%s%u", prefix, nbits); + nbits = nbits? nbits : 1; /* No nbits - oops - use 1 instead. */ + curvebuf = NULL; + } + else if (prefix && !*prefix) + { + const char *curvename; + + for (i=0; i < keyalgo_strings_used; i++) + { + if (keyalgo_strings[i].algo == algo + && keyalgo_strings[i].curve + && !strcmp (keyalgo_strings[i].curve, curve)) + return keyalgo_strings[i].name; + } + + /* Not yet in the table - add it. */ + curvename = openpgp_oid_or_name_to_curve (curve, 0); + if (curvename) + name = xasprintf ("%s", curvename); + else if (curve) + name = xasprintf ("E_%s", curve); + else + name = xasprintf ("E_error"); + nbits = 0; + curvebuf = xstrdup (curve); + } + else + { + for (i=0; i < keyalgo_strings_used; i++) + { + if (keyalgo_strings[i].algo == algo + && !keyalgo_strings[i].nbits + && !keyalgo_strings[i].curve) + return keyalgo_strings[i].name; + } + /* Not yet in the table - add it. */ + name = xasprintf ("unknown_%u", (unsigned int)algo); + nbits = 0; + curvebuf = NULL; + } + + /* Store a new entry. This is a loop because of a possible nPth + * thread switch during xrealloc. */ + while (keyalgo_strings_used >= keyalgo_strings_size) + { + keyalgo_strings_size += 10; + if (keyalgo_strings_size > 1024*1024) + log_fatal ("%s: table getting too large - possible DoS\n", __func__); + keyalgo_strings = xrealloc (keyalgo_strings, (keyalgo_strings_size + * sizeof *keyalgo_strings)); + } + keyalgo_strings[keyalgo_strings_used].algo = algo; + keyalgo_strings[keyalgo_strings_used].nbits = nbits; + keyalgo_strings[keyalgo_strings_used].curve = curvebuf; + keyalgo_strings[keyalgo_strings_used].name = name; + keyalgo_strings_used++; + + return name; /* Note that this is in the table. */ +} |