diff options
Diffstat (limited to 'agent/protect.c')
| -rw-r--r-- | agent/protect.c | 153 |
1 files changed, 152 insertions, 1 deletions
diff --git a/agent/protect.c b/agent/protect.c index 115a94563..ea8e30496 100644 --- a/agent/protect.c +++ b/agent/protect.c @@ -780,7 +780,7 @@ agent_unprotect (const unsigned char *protectedkey, const char *passphrase, PRIVATE_KEY_UNKNOWN if we can't figure out the type (this is the value 0), PRIVATE_KEY_CLEAR for an unprotected private key. PRIVATE_KEY_PROTECTED for an protected private key or - PRIVATE_KEY_SHADOWED for a sub key where the secret parts are store + PRIVATE_KEY_SHADOWED for a sub key where the secret parts are stored elsewhere. */ int agent_private_key_type (const unsigned char *privatekey) @@ -886,3 +886,154 @@ hash_passphrase (const char *passphrase, int hashalgo, } + +/* Create a shadow key from a public key. We use the shadow protocol + "ti-v1" and insert the S-expressionn SHADOW_INFO. The resulting + S-expression is returned in an allocated buffer RESULT will point + to. The input parameters are expected to be valid canonilized + S-expressions */ +int +agent_shadow_key (const unsigned char *pubkey, + const unsigned char *shadow_info, + unsigned char **result) +{ + const unsigned char *s; + const unsigned char *point; + size_t n; + int depth = 0; + unsigned char *p; + size_t pubkey_len = gcry_sexp_canon_len (pubkey, 0, NULL,NULL); + size_t shadow_info_len = gcry_sexp_canon_len (shadow_info, 0, NULL,NULL); + + if (!pubkey_len || !shadow_info_len) + return GNUPG_Invalid_Value; + s = pubkey; + if (*s != '(') + return GNUPG_Invalid_Sexp; + depth++; + s++; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + if (!smatch (&s, n, "public-key")) + return GNUPG_Unknown_Sexp; + if (*s != '(') + return GNUPG_Unknown_Sexp; + depth++; + s++; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + s += n; /* skip over the algorithm name */ + + while (*s != ')') + { + if (*s != '(') + return GNUPG_Invalid_Sexp; + depth++; + s++; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + s += n; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + s +=n; /* skip value */ + if (*s != ')') + return GNUPG_Invalid_Sexp; + depth--; + s++; + } + point = s; /* insert right before the point */ + depth--; + s++; + assert (depth == 1); + + /* calculate required length by taking in account: the "shadowed-" + prefix, the "shadowed", "t1-v1" as well as some parenthesis */ + n = 12 + pubkey_len + 1 + 3+8 + 2+5 + shadow_info_len + 1; + *result = p = xtrymalloc (n); + if (!p) + return GNUPG_Out_Of_Core; + p = stpcpy (p, "(20:shadowed-private-key"); + /* (10:public-key ...)*/ + memcpy (p, pubkey+14, point - (pubkey+14)); + p += point - (pubkey+14); + p = stpcpy (p, "(8:shadowed5:t1-v1"); + memcpy (p, shadow_info, shadow_info_len); + p += shadow_info_len; + *p++ = ')'; + memcpy (p, point, pubkey_len - (point - pubkey)); + p += pubkey_len - (point - pubkey); + + return 0; +} + +/* Parse a canonical encoded shadowed key and return a pointer to the + inner list with the shadow_info */ +int +agent_get_shadow_info (const unsigned char *shadowkey, + unsigned char const **shadow_info) +{ + const unsigned char *s; + size_t n; + int depth = 0; + + s = shadowkey; + if (*s != '(') + return GNUPG_Invalid_Sexp; + depth++; + s++; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + if (!smatch (&s, n, "shadowed-private-key")) + return GNUPG_Unknown_Sexp; + if (*s != '(') + return GNUPG_Unknown_Sexp; + depth++; + s++; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + s += n; /* skip over the algorithm name */ + + for (;;) + { + if (*s == ')') + return GNUPG_Unknown_Sexp; + if (*s != '(') + return GNUPG_Invalid_Sexp; + depth++; + s++; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + if (smatch (&s, n, "shadowed")) + break; + s += n; + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + s +=n; /* skip value */ + if (*s != ')') + return GNUPG_Invalid_Sexp; + depth--; + s++; + } + /* found the shadowed list, s points to the protocol */ + n = snext (&s); + if (!n) + return GNUPG_Invalid_Sexp; + if (smatch (&s, n, "t1-v1")) + { + if (*s != '(') + return GNUPG_Invalid_Sexp; + *shadow_info = s; + } + else + return GNUPG_Unsupported_Protocol; + return 0; +} + |