diff options
| -rw-r--r-- | Documentation/crypto/api-sig.rst | 2 | ||||
| -rw-r--r-- | crypto/asymmetric_keys/public_key.c | 38 | ||||
| -rw-r--r-- | crypto/ecdsa-x962.c | 36 | ||||
| -rw-r--r-- | crypto/ecdsa.c | 16 | ||||
| -rw-r--r-- | crypto/sig.c | 4 | ||||
| -rw-r--r-- | include/crypto/sig.h | 38 |
6 files changed, 99 insertions, 35 deletions
diff --git a/Documentation/crypto/api-sig.rst b/Documentation/crypto/api-sig.rst index 10dabc87df02..aaec18e26d54 100644 --- a/Documentation/crypto/api-sig.rst +++ b/Documentation/crypto/api-sig.rst @@ -11,5 +11,5 @@ Asymmetric Signature API :doc: Generic Public Key Signature API .. kernel-doc:: include/crypto/sig.h - :functions: crypto_alloc_sig crypto_free_sig crypto_sig_set_pubkey crypto_sig_set_privkey crypto_sig_keysize crypto_sig_sign crypto_sig_verify + :functions: crypto_alloc_sig crypto_free_sig crypto_sig_set_pubkey crypto_sig_set_privkey crypto_sig_keysize crypto_sig_maxsize crypto_sig_digestsize crypto_sig_sign crypto_sig_verify diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 8bf5aa329c26..ec2c0e009b49 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -202,6 +202,8 @@ static int software_key_query(const struct kernel_pkey_params *params, goto error_free_tfm; len = crypto_sig_keysize(sig); + info->max_sig_size = crypto_sig_maxsize(sig); + info->max_data_size = crypto_sig_digestsize(sig); info->supported_ops = KEYCTL_SUPPORTS_VERIFY; if (pkey->key_is_private) @@ -227,6 +229,8 @@ static int software_key_query(const struct kernel_pkey_params *params, goto error_free_tfm; len = crypto_akcipher_maxsize(tfm); + info->max_sig_size = len; + info->max_data_size = len; info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT; if (pkey->key_is_private) @@ -234,40 +238,6 @@ static int software_key_query(const struct kernel_pkey_params *params, } info->key_size = len * 8; - - if (strncmp(pkey->pkey_algo, "ecdsa", 5) == 0) { - int slen = len; - /* - * ECDSA key sizes are much smaller than RSA, and thus could - * operate on (hashed) inputs that are larger than key size. - * For example SHA384-hashed input used with secp256r1 - * based keys. Set max_data_size to be at least as large as - * the largest supported hash size (SHA512) - */ - info->max_data_size = 64; - - /* - * Verify takes ECDSA-Sig (described in RFC 5480) as input, - * which is actually 2 'key_size'-bit integers encoded in - * ASN.1. Account for the ASN.1 encoding overhead here. - * - * NIST P192/256/384 may prepend a '0' to a coordinate to - * indicate a positive integer. NIST P521 never needs it. - */ - if (strcmp(pkey->pkey_algo, "ecdsa-nist-p521") != 0) - slen += 1; - /* Length of encoding the x & y coordinates */ - slen = 2 * (slen + 2); - /* - * If coordinate encoding takes at least 128 bytes then an - * additional byte for length encoding is needed. - */ - info->max_sig_size = 1 + (slen >= 128) + 1 + slen; - } else { - info->max_data_size = len; - info->max_sig_size = len; - } - info->max_enc_size = len; info->max_dec_size = len; diff --git a/crypto/ecdsa-x962.c b/crypto/ecdsa-x962.c index 8a15232dfa77..6a77c13e192b 100644 --- a/crypto/ecdsa-x962.c +++ b/crypto/ecdsa-x962.c @@ -99,6 +99,40 @@ static unsigned int ecdsa_x962_key_size(struct crypto_sig *tfm) return crypto_sig_keysize(ctx->child); } +static unsigned int ecdsa_x962_max_size(struct crypto_sig *tfm) +{ + struct ecdsa_x962_ctx *ctx = crypto_sig_ctx(tfm); + struct sig_alg *alg = crypto_sig_alg(ctx->child); + int slen = crypto_sig_keysize(ctx->child); + + /* + * Verify takes ECDSA-Sig-Value (described in RFC 5480) as input, + * which is actually 2 'key_size'-bit integers encoded in ASN.1. + * Account for the ASN.1 encoding overhead here. + * + * NIST P192/256/384 may prepend a '0' to a coordinate to indicate + * a positive integer. NIST P521 never needs it. + */ + if (strcmp(alg->base.cra_name, "ecdsa-nist-p521") != 0) + slen += 1; + + /* Length of encoding the x & y coordinates */ + slen = 2 * (slen + 2); + + /* + * If coordinate encoding takes at least 128 bytes then an + * additional byte for length encoding is needed. + */ + return 1 + (slen >= 128) + 1 + slen; +} + +static unsigned int ecdsa_x962_digest_size(struct crypto_sig *tfm) +{ + struct ecdsa_x962_ctx *ctx = crypto_sig_ctx(tfm); + + return crypto_sig_digestsize(ctx->child); +} + static int ecdsa_x962_set_pub_key(struct crypto_sig *tfm, const void *key, unsigned int keylen) { @@ -180,6 +214,8 @@ static int ecdsa_x962_create(struct crypto_template *tmpl, struct rtattr **tb) inst->alg.verify = ecdsa_x962_verify; inst->alg.key_size = ecdsa_x962_key_size; + inst->alg.max_size = ecdsa_x962_max_size; + inst->alg.digest_size = ecdsa_x962_digest_size; inst->alg.set_pub_key = ecdsa_x962_set_pub_key; inst->free = ecdsa_x962_free; diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c index 6cb0a6ce9de1..cf8e0c5d1dd8 100644 --- a/crypto/ecdsa.c +++ b/crypto/ecdsa.c @@ -7,6 +7,7 @@ #include <crypto/internal/ecc.h> #include <crypto/internal/sig.h> #include <crypto/ecdh.h> +#include <crypto/sha2.h> #include <crypto/sig.h> struct ecc_ctx { @@ -169,6 +170,17 @@ static unsigned int ecdsa_key_size(struct crypto_sig *tfm) return DIV_ROUND_UP(ctx->curve->nbits, 8); } +static unsigned int ecdsa_digest_size(struct crypto_sig *tfm) +{ + /* + * ECDSA key sizes are much smaller than RSA, and thus could + * operate on (hashed) inputs that are larger than the key size. + * E.g. SHA384-hashed input used with secp256r1 based keys. + * Return the largest supported hash size (SHA512). + */ + return SHA512_DIGEST_SIZE; +} + static int ecdsa_nist_p521_init_tfm(struct crypto_sig *tfm) { struct ecc_ctx *ctx = crypto_sig_ctx(tfm); @@ -180,6 +192,7 @@ static struct sig_alg ecdsa_nist_p521 = { .verify = ecdsa_verify, .set_pub_key = ecdsa_set_pub_key, .key_size = ecdsa_key_size, + .digest_size = ecdsa_digest_size, .init = ecdsa_nist_p521_init_tfm, .exit = ecdsa_exit_tfm, .base = { @@ -202,6 +215,7 @@ static struct sig_alg ecdsa_nist_p384 = { .verify = ecdsa_verify, .set_pub_key = ecdsa_set_pub_key, .key_size = ecdsa_key_size, + .digest_size = ecdsa_digest_size, .init = ecdsa_nist_p384_init_tfm, .exit = ecdsa_exit_tfm, .base = { @@ -224,6 +238,7 @@ static struct sig_alg ecdsa_nist_p256 = { .verify = ecdsa_verify, .set_pub_key = ecdsa_set_pub_key, .key_size = ecdsa_key_size, + .digest_size = ecdsa_digest_size, .init = ecdsa_nist_p256_init_tfm, .exit = ecdsa_exit_tfm, .base = { @@ -246,6 +261,7 @@ static struct sig_alg ecdsa_nist_p192 = { .verify = ecdsa_verify, .set_pub_key = ecdsa_set_pub_key, .key_size = ecdsa_key_size, + .digest_size = ecdsa_digest_size, .init = ecdsa_nist_p192_init_tfm, .exit = ecdsa_exit_tfm, .base = { diff --git a/crypto/sig.c b/crypto/sig.c index 7a3521bee29a..be5ac0e59384 100644 --- a/crypto/sig.c +++ b/crypto/sig.c @@ -127,6 +127,10 @@ int crypto_register_sig(struct sig_alg *alg) return -EINVAL; if (!alg->key_size) return -EINVAL; + if (!alg->max_size) + alg->max_size = alg->key_size; + if (!alg->digest_size) + alg->digest_size = alg->key_size; sig_prepare_alg(alg); return crypto_register_alg(base); diff --git a/include/crypto/sig.h b/include/crypto/sig.h index a3ef17c5f72f..cff41ad93824 100644 --- a/include/crypto/sig.h +++ b/include/crypto/sig.h @@ -33,6 +33,8 @@ struct crypto_sig { * function, which knows how to decode and interpret * the BER encoded private key and parameters. Optional. * @key_size: Function returns key size. Mandatory. + * @digest_size: Function returns maximum digest size. Optional. + * @max_size: Function returns maximum signature size. Optional. * @init: Initialize the cryptographic transformation object. * This function is used to initialize the cryptographic * transformation object. This function is called only once at @@ -59,6 +61,8 @@ struct sig_alg { int (*set_priv_key)(struct crypto_sig *tfm, const void *key, unsigned int keylen); unsigned int (*key_size)(struct crypto_sig *tfm); + unsigned int (*digest_size)(struct crypto_sig *tfm); + unsigned int (*max_size)(struct crypto_sig *tfm); int (*init)(struct crypto_sig *tfm); void (*exit)(struct crypto_sig *tfm); @@ -138,6 +142,40 @@ static inline unsigned int crypto_sig_keysize(struct crypto_sig *tfm) } /** + * crypto_sig_digestsize() - Get maximum digest size + * + * Function returns the maximum digest size in bytes. + * Function assumes that the key is already set in the transformation. If this + * function is called without a setkey or with a failed setkey, you may end up + * in a NULL dereference. + * + * @tfm: signature tfm handle allocated with crypto_alloc_sig() + */ +static inline unsigned int crypto_sig_digestsize(struct crypto_sig *tfm) +{ + struct sig_alg *alg = crypto_sig_alg(tfm); + + return alg->digest_size(tfm); +} + +/** + * crypto_sig_maxsize() - Get maximum signature size + * + * Function returns the maximum signature size in bytes. + * Function assumes that the key is already set in the transformation. If this + * function is called without a setkey or with a failed setkey, you may end up + * in a NULL dereference. + * + * @tfm: signature tfm handle allocated with crypto_alloc_sig() + */ +static inline unsigned int crypto_sig_maxsize(struct crypto_sig *tfm) +{ + struct sig_alg *alg = crypto_sig_alg(tfm); + + return alg->max_size(tfm); +} + +/** * crypto_sig_sign() - Invoke signing operation * * Function invokes the specific signing operation for a given algorithm |