diff options
Diffstat (limited to 'src/libstrongswan/credentials/keys/signature_params.c')
| -rw-r--r-- | src/libstrongswan/credentials/keys/signature_params.c | 50 |
1 files changed, 34 insertions, 16 deletions
diff --git a/src/libstrongswan/credentials/keys/signature_params.c b/src/libstrongswan/credentials/keys/signature_params.c index 8f42fb940..d89bd2c96 100644 --- a/src/libstrongswan/credentials/keys/signature_params.c +++ b/src/libstrongswan/credentials/keys/signature_params.c @@ -18,22 +18,43 @@ #include <asn1/oid.h> #include <asn1/asn1_parser.h> -/** - * Determine the salt length in case it is not configured +/* + * Described in header */ -static ssize_t rsa_pss_salt_length(rsa_pss_params_t *pss) +bool rsa_pss_params_set_salt_len(rsa_pss_params_t *params, size_t modbits) { - ssize_t salt_len = pss->salt_len; + size_t hash_len; - if (salt_len <= RSA_PSS_SALT_LEN_DEFAULT) + if (params->salt_len < 0) { - salt_len = hasher_hash_size(pss->hash); - if (!salt_len) + hash_len = hasher_hash_size(params->hash); + if (!hash_len) + { + return FALSE; + } + + switch (params->salt_len) { - return -1; + case RSA_PSS_SALT_LEN_DEFAULT: + params->salt_len = hash_len; + break; + case RSA_PSS_SALT_LEN_MAX: + if (modbits) + { + /* emBits = modBits - 1 */ + modbits -= 1; + /* emLen = ceil(emBits/8) */ + modbits = (modbits+7) / BITS_PER_BYTE; + /* account for 0x01 separator in DB, 0xbc trailing byte */ + params->salt_len = max(0, (ssize_t)(modbits - hash_len - 2)); + break; + } + return FALSE; + default: + return FALSE; } } - return salt_len; + return TRUE; } /** @@ -68,8 +89,7 @@ static bool compare_params(signature_params_t *a, signature_params_t *b, return pss_a->hash == pss_b->hash && pss_a->mgf1_hash == pss_b->mgf1_hash && - (!strict || - rsa_pss_salt_length(pss_a) == rsa_pss_salt_length(pss_b)); + (!strict || pss_a->salt_len == pss_b->salt_len); } default: break; @@ -328,7 +348,6 @@ end: bool rsa_pss_params_build(rsa_pss_params_t *params, chunk_t *asn1) { chunk_t hash = chunk_empty, mgf = chunk_empty, slen = chunk_empty; - ssize_t salt_len; int alg; if (params->hash != HASH_SHA1) @@ -351,16 +370,15 @@ bool rsa_pss_params_build(rsa_pss_params_t *params, chunk_t *asn1) mgf = asn1_algorithmIdentifier_params(OID_MGF1, asn1_algorithmIdentifier(alg)); } - salt_len = rsa_pss_salt_length(params); - if (salt_len < 0) + if (params->salt_len < 0) { chunk_free(&hash); chunk_free(&mgf); return FALSE; } - else if (salt_len != HASH_SIZE_SHA1) + else if (params->salt_len != HASH_SIZE_SHA1) { - slen = asn1_integer("m", asn1_integer_from_uint64(salt_len)); + slen = asn1_integer("m", asn1_integer_from_uint64(params->salt_len)); } *asn1 = asn1_wrap(ASN1_SEQUENCE, "mmm", hash.len ? asn1_wrap(ASN1_CONTEXT_C_0, "m", hash) : chunk_empty, |