From 786dd2c22c71081492e209d93beee3ff4fe66357 Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Fri, 21 Apr 2017 15:56:34 +0100 Subject: [PATCH] Add support for custom signature parameters Many signature types define the digest and public key type by a single OID such as ecdsa_with_sha256. Some types (RSA-PSS for example) use a single OID to indicate the signature scheme and additional parameters are encoded in the AlgorithmIdentifier. Add an X509_SIG_INFO structure to contain details about the signature type: specifically the digest algorithm, public key algorithm, security bits and various flags. This supports both existing algorithms and more complex types. Add accessors for the structure and a special case that retrieves signature information from a certificate. Reviewed-by: Richard Levitte (Merged from https://github.com/openssl/openssl/pull/3301) --- crypto/include/internal/asn1_int.h | 2 + crypto/include/internal/x509_int.h | 16 +++++++ crypto/x509/x509_lcl.h | 3 ++ crypto/x509/x509_set.c | 77 ++++++++++++++++++++++++++++++ crypto/x509v3/v3_purp.c | 1 + include/openssl/ossl_typ.h | 2 + include/openssl/x509.h | 15 ++++++ 7 files changed, 116 insertions(+) diff --git a/crypto/include/internal/asn1_int.h b/crypto/include/internal/asn1_int.h index f78ced6dab..6e6e028738 100644 --- a/crypto/include/internal/asn1_int.h +++ b/crypto/include/internal/asn1_int.h @@ -52,6 +52,8 @@ struct evp_pkey_asn1_method_st { int (*item_sign) (EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn, X509_ALGOR *alg1, X509_ALGOR *alg2, ASN1_BIT_STRING *sig); + int (*siginf_set) (X509_SIG_INFO *siginf, const X509_ALGOR *alg, + const ASN1_STRING *sig); } /* EVP_PKEY_ASN1_METHOD */ ; DEFINE_STACK_OF_CONST(EVP_PKEY_ASN1_METHOD) diff --git a/crypto/include/internal/x509_int.h b/crypto/include/internal/x509_int.h index 10b605f709..124cc533bc 100644 --- a/crypto/include/internal/x509_int.h +++ b/crypto/include/internal/x509_int.h @@ -37,6 +37,19 @@ struct X509_name_st { int canon_enclen; } /* X509_NAME */ ; +/* Signature info structure */ + +struct x509_sig_info_st { + /* NID of message digest */ + int mdnid; + /* NID of public key algorithm */ + int pknid; + /* Security bits */ + int secbits; + /* Various flags */ + uint32_t flags; +}; + /* PKCS#10 certificate request */ struct X509_req_info_st { @@ -146,6 +159,7 @@ struct x509_st { X509_CINF cert_info; X509_ALGOR sig_alg; ASN1_BIT_STRING signature; + X509_SIG_INFO siginf; CRYPTO_REF_COUNT references; CRYPTO_EX_DATA ex_data; /* These contain copies of various extension values */ @@ -267,3 +281,5 @@ struct x509_object_st { int a2i_ipadd(unsigned char *ipout, const char *ipasc); int x509_set1_time(ASN1_TIME **ptm, const ASN1_TIME *tm); + +void x509_init_sig_info(X509 *x); diff --git a/crypto/x509/x509_lcl.h b/crypto/x509/x509_lcl.h index 34e413530a..401f2e9f55 100644 --- a/crypto/x509/x509_lcl.h +++ b/crypto/x509/x509_lcl.h @@ -142,3 +142,6 @@ DEFINE_STACK_OF(BY_DIR_HASH) DEFINE_STACK_OF(BY_DIR_ENTRY) typedef STACK_OF(X509_NAME_ENTRY) STACK_OF_X509_NAME_ENTRY; DEFINE_STACK_OF(STACK_OF_X509_NAME_ENTRY) + +void x509_set_signature_info(X509_SIG_INFO *siginf, const X509_ALGOR *alg, + const ASN1_STRING *sig); diff --git a/crypto/x509/x509_set.c b/crypto/x509/x509_set.c index e46174a463..08b71ff582 100644 --- a/crypto/x509/x509_set.c +++ b/crypto/x509/x509_set.c @@ -13,7 +13,10 @@ #include #include #include +#include +#include "internal/asn1_int.h" #include "internal/x509_int.h" +#include "x509_lcl.h" int X509_set_version(X509 *x, long version) { @@ -157,3 +160,77 @@ const X509_ALGOR *X509_get0_tbs_sigalg(const X509 *x) { return &x->cert_info.signature; } + +int X509_SIG_INFO_get(const X509_SIG_INFO *siginf, int *mdnid, int *pknid, + int *secbits, uint32_t *flags) +{ + if (mdnid != NULL) + *mdnid = siginf->mdnid; + if (pknid != NULL) + *pknid = siginf->pknid; + if (secbits != NULL) + *secbits = siginf->secbits; + if (flags != NULL) + *flags = siginf->flags; + return (siginf->flags & X509_SIG_INFO_VALID) != 0; +} + +void X509_SIG_INFO_set(X509_SIG_INFO *siginf, int mdnid, int pknid, + int secbits, uint32_t flags) +{ + siginf->mdnid = mdnid; + siginf->pknid = pknid; + siginf->secbits = secbits; + siginf->flags = flags; +} + +int X509_get_signature_info(X509 *x, int *mdnid, int *pknid, int *secbits, + uint32_t *flags) +{ + X509_check_purpose(x, -1, -1); + return X509_SIG_INFO_get(&x->siginf, mdnid, pknid, secbits, flags); +} + +static void x509_sig_info_init(X509_SIG_INFO *siginf, const X509_ALGOR *alg, + const ASN1_STRING *sig) +{ + int pknid, mdnid; + const EVP_MD *md; + + siginf->mdnid = NID_undef; + siginf->pknid = NID_undef; + siginf->secbits = -1; + siginf->flags = 0; + if (!OBJ_find_sigid_algs(OBJ_obj2nid(alg->algorithm), &mdnid, &pknid) + || pknid == NID_undef) + return; + siginf->pknid = pknid; + if (mdnid == NID_undef) { + /* If we have one, use a custom handler for this algorithm */ + const EVP_PKEY_ASN1_METHOD *ameth = EVP_PKEY_asn1_find(NULL, pknid); + if (ameth == NULL || ameth->siginf_set == NULL + || ameth->siginf_set(siginf, alg, sig) == 0) + return; + siginf->flags |= X509_SIG_INFO_VALID; + return; + } + siginf->flags |= X509_SIG_INFO_VALID; + siginf->mdnid = mdnid; + md = EVP_get_digestbynid(mdnid); + if (md == NULL) + return; + /* Security bits: half number of bits in digest */ + siginf->secbits = EVP_MD_size(md) * 4; + switch (mdnid) { + case NID_sha1: + case NID_sha256: + case NID_sha384: + case NID_sha512: + siginf->flags |= X509_SIG_INFO_TLS; + } +} + +void x509_init_sig_info(X509 *x) +{ + x509_sig_info_init(&x->siginf, &x->sig_alg, &x->signature); +} diff --git a/crypto/x509v3/v3_purp.c b/crypto/x509v3/v3_purp.c index fa5c425ffc..2ff8854ca3 100644 --- a/crypto/x509v3/v3_purp.c +++ b/crypto/x509v3/v3_purp.c @@ -488,6 +488,7 @@ static void x509v3_cache_extensions(X509 *x) break; } } + x509_init_sig_info(x); x->ex_flags |= EXFLAG_SET; } diff --git a/include/openssl/ossl_typ.h b/include/openssl/ossl_typ.h index 129a67f057..deea03899a 100644 --- a/include/openssl/ossl_typ.h +++ b/include/openssl/ossl_typ.h @@ -131,6 +131,8 @@ typedef struct x509_lookup_st X509_LOOKUP; typedef struct x509_lookup_method_st X509_LOOKUP_METHOD; typedef struct X509_VERIFY_PARAM_st X509_VERIFY_PARAM; +typedef struct x509_sig_info_st X509_SIG_INFO; + typedef struct pkcs8_priv_key_info_st PKCS8_PRIV_KEY_INFO; typedef struct v3_ext_ctx X509V3_CTX; diff --git a/include/openssl/x509.h b/include/openssl/x509.h index a6aabebd9c..0a692f803e 100644 --- a/include/openssl/x509.h +++ b/include/openssl/x509.h @@ -39,6 +39,13 @@ extern "C" { #endif + +/* Flags for X509_get_signature_info() */ +/* Signature info is valid */ +# define X509_SIG_INFO_VALID 0x1 +/* Signature is suitable for TLS use */ +# define X509_SIG_INFO_TLS 0x2 + # define X509_FILETYPE_PEM 1 # define X509_FILETYPE_ASN1 2 # define X509_FILETYPE_DEFAULT 3 @@ -549,6 +556,14 @@ X509 *d2i_X509_AUX(X509 **a, const unsigned char **pp, long length); int i2d_re_X509_tbs(X509 *x, unsigned char **pp); +int X509_SIG_INFO_get(const X509_SIG_INFO *siginf, int *mdnid, int *pknid, + int *secbits, uint32_t *flags); +void X509_SIG_INFO_set(X509_SIG_INFO *siginf, int mdnid, int pknid, + int secbits, uint32_t flags); + +int X509_get_signature_info(X509 *x, int *mdnid, int *pknid, int *secbits, + uint32_t *flags); + void X509_get0_signature(const ASN1_BIT_STRING **psig, const X509_ALGOR **palg, const X509 *x); int X509_get_signature_nid(const X509 *x); -- 2.25.1