diff options
Diffstat (limited to 'src/libstrongswan/plugins/gmp/gmp_rsa_public_key.c')
| -rw-r--r-- | src/libstrongswan/plugins/gmp/gmp_rsa_public_key.c | 253 |
1 files changed, 230 insertions, 23 deletions
diff --git a/src/libstrongswan/plugins/gmp/gmp_rsa_public_key.c b/src/libstrongswan/plugins/gmp/gmp_rsa_public_key.c index acb44a110..4c779703b 100644 --- a/src/libstrongswan/plugins/gmp/gmp_rsa_public_key.c +++ b/src/libstrongswan/plugins/gmp/gmp_rsa_public_key.c @@ -28,11 +28,7 @@ #include <asn1/asn1_parser.h> #include <asn1/pem.h> #include <crypto/hashers/hasher.h> - -/** - * defined in gmp_rsa_private_key.c - */ -extern chunk_t gmp_mpz_to_asn1(const mpz_t value); +#include <pgp/pgp.h> typedef struct private_gmp_rsa_public_key_t private_gmp_rsa_public_key_t; @@ -77,6 +73,12 @@ struct private_gmp_rsa_public_key_t { }; /** + * Shared functions defined in gmp_rsa_private_key.c + */ +extern chunk_t gmp_mpz_to_chunk(const mpz_t value); +extern chunk_t gmp_mpz_to_asn1(const mpz_t value); + +/** * RSAEP algorithm specified in PKCS#1. */ static chunk_t rsaep(private_gmp_rsa_public_key_t *this, chunk_t data) @@ -189,13 +191,24 @@ static bool verify_emsa_pkcs1_signature(private_gmp_rsa_public_key_t *this, goto end; } - /* parse ASN.1-based digestInfo */ - { + if (algorithm == HASH_UNKNOWN) + { /* IKEv1 signatures without digestInfo */ + if (em.len != data.len) + { + DBG1("hash size in signature is %u bytes instead of %u bytes", + em.len, data.len); + goto end; + } + success = memeq(em.ptr, data.ptr, data.len); + } + else + { /* IKEv2 and X.509 certificate signatures */ asn1_parser_t *parser; chunk_t object; int objectID; hash_algorithm_t hash_algorithm = HASH_UNKNOWN; + DBG2("signature verification:"); parser = asn1_parser_create(digestInfoObjects, em); while (parser->iterate(parser, &objectID, &object)) @@ -218,8 +231,7 @@ static bool verify_emsa_pkcs1_signature(private_gmp_rsa_public_key_t *this, parser->get_level(parser)+1, NULL); hash_algorithm = hasher_algorithm_from_oid(hash_oid); - if (hash_algorithm == HASH_UNKNOWN || - (algorithm != HASH_UNKNOWN && hash_algorithm != algorithm)) + if (hash_algorithm == HASH_UNKNOWN || hash_algorithm != algorithm) { DBG1("expected hash algorithm %N, but found %N (OID: %#B)", hash_algorithm_names, algorithm, @@ -287,7 +299,8 @@ static bool verify(private_gmp_rsa_public_key_t *this, signature_scheme_t scheme { switch (scheme) { - case SIGN_DEFAULT: /* default is EMSA-PKCS1 using included OID */ + case SIGN_DEFAULT: + case SIGN_RSA_EMSA_PKCS1_NULL: return verify_emsa_pkcs1_signature(this, HASH_UNKNOWN, data, signature); case SIGN_RSA_EMSA_PKCS1_MD5: return verify_emsa_pkcs1_signature(this, HASH_MD5, data, signature); @@ -316,6 +329,34 @@ static bool encrypt_(private_gmp_rsa_public_key_t *this, chunk_t crypto, chunk_t } /** + * Implementation of gmp_rsa_public_key.equals. + */ +static bool equals(private_gmp_rsa_public_key_t *this, public_key_t *other) +{ + identification_t *keyid; + + if (&this->public.interface == other) + { + return TRUE; + } + if (other->get_type(other) != KEY_RSA) + { + return FALSE; + } + keyid = other->get_id(other, ID_PUBKEY_SHA1); + if (keyid && keyid->equals(keyid, this->keyid)) + { + return TRUE; + } + keyid = other->get_id(other, ID_PUBKEY_INFO_SHA1); + if (keyid && keyid->equals(keyid, this->keyid_info)) + { + return TRUE; + } + return FALSE; +} + +/** * Implementation of public_key_t.get_keysize. */ static size_t get_keysize(private_gmp_rsa_public_key_t *this) @@ -324,6 +365,34 @@ static size_t get_keysize(private_gmp_rsa_public_key_t *this) } /** + * Build the PGP version 3 RSA key identifier from n and e using + * MD5 hashed modulus and exponent. Also used in rsa_private_key.c. + */ +static identification_t* gmp_rsa_build_pgp_v3_keyid(mpz_t n, mpz_t e) +{ + identification_t *keyid; + chunk_t modulus, exponent, hash; + hasher_t *hasher; + + hasher= lib->crypto->create_hasher(lib->crypto, HASH_MD5); + if (hasher == NULL) + { + DBG1("computation of PGP V3 key ID failed, no MD5 hasher is available"); + return NULL; + } + modulus = gmp_mpz_to_chunk(n); + exponent = gmp_mpz_to_chunk(e); + hasher->allocate_hash(hasher, modulus, NULL); + hasher->allocate_hash(hasher, exponent, &hash); + hasher->destroy(hasher); + keyid = identification_create_from_encoding(ID_PUBKEY_SHA1, hash); + free(hash.ptr); + free(modulus.ptr); + free(exponent.ptr); + return keyid; +} + +/** * Implementation of public_key_t.get_id. */ static identification_t *get_id(private_gmp_rsa_public_key_t *this, @@ -335,6 +404,8 @@ static identification_t *get_id(private_gmp_rsa_public_key_t *this, return this->keyid_info; case ID_PUBKEY_SHA1: return this->keyid; + case ID_KEY_ID: + return gmp_rsa_build_pgp_v3_keyid(this->n, this->e); default: return NULL; } @@ -381,14 +452,15 @@ static private_gmp_rsa_public_key_t *gmp_rsa_public_key_create_empty() { private_gmp_rsa_public_key_t *this = malloc_thing(private_gmp_rsa_public_key_t); - this->public.interface.get_type = (key_type_t (*)(public_key_t *this))get_type; - this->public.interface.verify = (bool (*)(public_key_t *this, signature_scheme_t scheme, chunk_t data, chunk_t signature))verify; - this->public.interface.encrypt = (bool (*)(public_key_t *this, chunk_t crypto, chunk_t *plain))encrypt_; - this->public.interface.get_keysize = (size_t (*) (public_key_t *this))get_keysize; - this->public.interface.get_id = (identification_t* (*) (public_key_t *this,id_type_t))get_id; - this->public.interface.get_encoding = (chunk_t(*)(public_key_t*))get_encoding; - this->public.interface.get_ref = (public_key_t* (*)(public_key_t *this))get_ref; - this->public.interface.destroy = (void (*)(public_key_t *this))destroy; + this->public.interface.get_type = (key_type_t (*) (public_key_t*))get_type; + this->public.interface.verify = (bool (*) (public_key_t*, signature_scheme_t, chunk_t, chunk_t))verify; + this->public.interface.encrypt = (bool (*) (public_key_t*, chunk_t, chunk_t*))encrypt_; + this->public.interface.equals = (bool (*) (public_key_t*, public_key_t*))equals; + this->public.interface.get_keysize = (size_t (*) (public_key_t*))get_keysize; + this->public.interface.get_id = (identification_t* (*) (public_key_t*, id_type_t))get_id; + this->public.interface.get_encoding = (chunk_t(*) (public_key_t*))get_encoding; + this->public.interface.get_ref = (public_key_t* (*) (public_key_t *this))get_ref; + this->public.interface.destroy = (void (*) (public_key_t *this))destroy; this->keyid = NULL; this->keyid_info = NULL; @@ -443,7 +515,7 @@ gmp_rsa_public_key_t *gmp_rsa_public_key_create_from_n_e(mpz_t n, mpz_t e) mpz_init_set(this->n, n); mpz_init_set(this->e, e); - this->k = (mpz_sizeinbase(this->n, 2) + 7) / 8; + this->k = (mpz_sizeinbase(this->n, 2) + 7) / BITS_PER_BYTE; if (!gmp_rsa_public_key_build_id(this->n, this->e, &this->keyid, &this->keyid_info)) { @@ -467,9 +539,9 @@ static const asn1Object_t pubkeyObjects[] = { #define PUB_KEY_EXPONENT 2 /** - * Load a public key from an ASN1 encoded blob + * Load a public key from an ASN.1 encoded blob */ -static gmp_rsa_public_key_t *load(chunk_t blob) +static gmp_rsa_public_key_t *load_asn1_der(chunk_t blob) { asn1_parser_t *parser; chunk_t object; @@ -505,7 +577,121 @@ static gmp_rsa_public_key_t *load(chunk_t blob) return NULL; } - this->k = (mpz_sizeinbase(this->n, 2) + 7) / 8; + this->k = (mpz_sizeinbase(this->n, 2) + 7) / BITS_PER_BYTE; + + if (!gmp_rsa_public_key_build_id(this->n, this->e, + &this->keyid, &this->keyid_info)) + { + destroy(this); + return NULL; + } + return &this->public; +} + +/** + * Load a public key from an OpenPGP blob + */ +static gmp_rsa_public_key_t* load_pgp(chunk_t blob) +{ + chunk_t exponent, modulus; + chunk_t packet = blob; + private_gmp_rsa_public_key_t *this = gmp_rsa_public_key_create_empty(); + + mpz_init(this->n); + mpz_init(this->e); + + /* modulus n */ + modulus.len = (pgp_length(&packet, 2) + 7) / BITS_PER_BYTE; + modulus.ptr = packet.ptr; + if (modulus.len > packet.len) + { + DBG1("OpenPGP public key blob too short for modulus"); + goto end; + } + packet.ptr += modulus.len; + packet.len -= modulus.len; + DBG2("L3 - modulus:"); + DBG3("%B", &modulus); + + /* public exponent e */ + exponent.len = (pgp_length(&packet, 2) + 7) / BITS_PER_BYTE; + exponent.ptr = packet.ptr; + if (exponent.len > packet.len) + { + DBG1("OpenPGP public key blob too short for exponent"); + goto end; + } + DBG2("L3 - public exponent:"); + DBG3("%B", &exponent); + + mpz_import(this->n, modulus.len, 1, 1, 1, 0, modulus.ptr); + mpz_import(this->e, exponent.len, 1, 1, 1, 0, exponent.ptr); + this->k = (mpz_sizeinbase(this->n, 2) + 7) / BITS_PER_BYTE; + free(blob.ptr); + + if (!gmp_rsa_public_key_build_id(this->n, this->e, + &this->keyid, &this->keyid_info)) + { + destroy(this); + return NULL; + } + return &this->public; + +end: + free(blob.ptr); + destroy(this); + return NULL; +} + +/** + * Load a public key from an RFC 3110 encoded blob + */ +static gmp_rsa_public_key_t *load_rfc_3110(chunk_t blob) +{ + chunk_t exponent, modulus; + u_char *pos = blob.ptr; + size_t len = blob.len; + private_gmp_rsa_public_key_t *this = gmp_rsa_public_key_create_empty(); + + mpz_init(this->n); + mpz_init(this->e); + + if (blob.len < 3) + { + DBG1("RFC 3110 public key blob too short for exponent length"); + goto end; + } + if (pos[0] != 0x00) + { + exponent = chunk_create(pos + 1, pos[0]); + pos++; + len--; + } + else + { + exponent = chunk_create(pos + 3, 256*pos[1] + pos[2]); + pos += 3; + len -= 3; + } + if (exponent.len > len) + { + DBG1("RFC 3110 public key blob too short for exponent"); + goto end; + } + pos += exponent.len; + len -= exponent.len; + + if (len == 0) + { + DBG1("RFC 3110 public key blob has zero length modulus"); + goto end; + } + modulus = chunk_create(pos, len); + + mpz_import(this->n, modulus.len, 1, 1, 1, 0, modulus.ptr); + mpz_import(this->e, exponent.len, 1, 1, 1, 0, exponent.ptr); + this->k = (mpz_sizeinbase(this->n, 2) + 7) / BITS_PER_BYTE; + free(blob.ptr); if (!gmp_rsa_public_key_build_id(this->n, this->e, &this->keyid, &this->keyid_info)) @@ -514,6 +700,11 @@ static gmp_rsa_public_key_t *load(chunk_t blob) return NULL; } return &this->public; + +end: + free(blob.ptr); + destroy(this); + return NULL; } typedef struct private_builder_t private_builder_t; @@ -554,7 +745,23 @@ static void add(private_builder_t *this, builder_part_t part, ...) { va_start(args, part); chunk = va_arg(args, chunk_t); - this->key = load(chunk_clone(chunk)); + this->key = load_asn1_der(chunk_clone(chunk)); + va_end(args); + return; + } + case BUILD_BLOB_PGP: + { + va_start(args, part); + chunk = va_arg(args, chunk_t); + this->key = load_pgp(chunk_clone(chunk)); + va_end(args); + return; + } + case BUILD_BLOB_RFC_3110: + { + va_start(args, part); + chunk = va_arg(args, chunk_t); + this->key = load_rfc_3110(chunk_clone(chunk)); va_end(args); return; } |