diff --git a/library/rsa.c b/library/rsa.c index e0c38c3bcf..b81039ceb9 100644 --- a/library/rsa.c +++ b/library/rsa.c @@ -46,6 +46,338 @@ #include "mbedtls/platform.h" +int mbedtls_rsa_key_parse(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen) +{ + int ret, version; + size_t len; + unsigned char *p, *end; + + mbedtls_mpi T; + mbedtls_mpi_init(&T); + + p = (unsigned char *) key; + end = p + keylen; + + /* + * This function parses the RSAPrivateKey (PKCS#1) + * + * RSAPrivateKey ::= SEQUENCE { + * version Version, + * modulus INTEGER, -- n + * publicExponent INTEGER, -- e + * privateExponent INTEGER, -- d + * prime1 INTEGER, -- p + * prime2 INTEGER, -- q + * exponent1 INTEGER, -- d mod (p-1) + * exponent2 INTEGER, -- d mod (q-1) + * coefficient INTEGER, -- (inverse of q) mod p + * otherPrimeInfos OtherPrimeInfos OPTIONAL + * } + */ + if ((ret = mbedtls_asn1_get_tag(&p, end, &len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { + return ret; + } + + end = p + len; + + if ((ret = mbedtls_asn1_get_int(&p, end, &version)) != 0) { + return ret; + } + + if (version != 0) { + return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; + } + + /* Import N */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = mbedtls_rsa_import(rsa, &T, NULL, NULL, + NULL, NULL)) != 0) { + goto cleanup; + } + + /* Import E */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL, + NULL, &T)) != 0) { + goto cleanup; + } + + /* Import D */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL, + &T, NULL)) != 0) { + goto cleanup; + } + + /* Import P */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = mbedtls_rsa_import(rsa, NULL, &T, NULL, + NULL, NULL)) != 0) { + goto cleanup; + } + + /* Import Q */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = mbedtls_rsa_import(rsa, NULL, NULL, &T, + NULL, NULL)) != 0) { + goto cleanup; + } + +#if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT) + /* + * The RSA CRT parameters DP, DQ and QP are nominally redundant, in + * that they can be easily recomputed from D, P and Q. However by + * parsing them from the PKCS1 structure it is possible to avoid + * recalculating them which both reduces the overhead of loading + * RSA private keys into memory and also avoids side channels which + * can arise when computing those values, since all of D, P, and Q + * are secret. See https://eprint.iacr.org/2020/055 for a + * description of one such attack. + */ + + /* Import DP */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = mbedtls_mpi_copy(&rsa->DP, &T)) != 0) { + goto cleanup; + } + + /* Import DQ */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = mbedtls_mpi_copy(&rsa->DQ, &T)) != 0) { + goto cleanup; + } + + /* Import QP */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = mbedtls_mpi_copy(&rsa->QP, &T)) != 0) { + goto cleanup; + } + +#else + /* Verify existence of the CRT params */ + if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || + (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0) { + goto cleanup; + } +#endif + + /* rsa_complete() doesn't complete anything with the default + * implementation but is still called: + * - for the benefit of alternative implementation that may want to + * pre-compute stuff beyond what's provided (eg Montgomery factors) + * - as is also sanity-checks the key + * + * Furthermore, we also check the public part for consistency with + * mbedtls_pk_parse_pubkey(), as it includes size minima for example. + */ + if ((ret = mbedtls_rsa_complete(rsa)) != 0 || + (ret = mbedtls_rsa_check_pubkey(rsa)) != 0) { + goto cleanup; + } + + if (p != end) { + ret = MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; + } + +cleanup: + + mbedtls_mpi_free(&T); + + if (ret != 0) { + mbedtls_rsa_free(rsa); + } + + return ret; +} + +int mbedtls_rsa_pubkey_parse(mbedtls_rsa_context *rsa, unsigned char **p, + const unsigned char *end) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t len; + + /* + * RSAPublicKey ::= SEQUENCE { + * modulus INTEGER, -- n + * publicExponent INTEGER -- e + * } + */ + + if ((ret = mbedtls_asn1_get_tag(p, end, &len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { + return ret; + } + + if (*p + len != end) { + return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; + } + + /* Import N */ + if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) { + return ret; + } + + if ((ret = mbedtls_rsa_import_raw(rsa, *p, len, NULL, 0, NULL, 0, + NULL, 0, NULL, 0)) != 0) { + return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; + } + + *p += len; + + /* Import E */ + if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) { + return ret; + } + + if ((ret = mbedtls_rsa_import_raw(rsa, NULL, 0, NULL, 0, NULL, 0, + NULL, 0, *p, len)) != 0) { + return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; + } + + *p += len; + + if (mbedtls_rsa_complete(rsa) != 0 || + mbedtls_rsa_check_pubkey(rsa) != 0) { + return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; + } + + if (*p != end) { + return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; + } + + return 0; +} + +int mbedtls_rsa_key_write(const mbedtls_rsa_context *rsa, unsigned char *start, + unsigned char **p) +{ + size_t len = 0; + int ret; + + mbedtls_mpi T; /* Temporary holding the exported parameters */ + + /* + * Export the parameters one after another to avoid simultaneous copies. + */ + + mbedtls_mpi_init(&T); + + /* Export QP */ + if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + + /* Export DQ */ + if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + + /* Export DP */ + if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + + /* Export Q */ + if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, &T, NULL, NULL)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + + /* Export P */ + if ((ret = mbedtls_rsa_export(rsa, NULL, &T, NULL, NULL, NULL)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + + /* Export D */ + if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, &T, NULL)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + + /* Export E */ + if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + + /* Export N */ + if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + +end_of_export: + + mbedtls_mpi_free(&T); + if (ret < 0) { + return ret; + } + + MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, start, 0)); + MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); + MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, + MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE)); + + return (int) len; +} + +/* + * RSAPublicKey ::= SEQUENCE { + * modulus INTEGER, -- n + * publicExponent INTEGER -- e + * } + */ +int mbedtls_rsa_pubkey_write(const mbedtls_rsa_context *rsa, unsigned char *start, + unsigned char **p) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t len = 0; + mbedtls_mpi T; + + mbedtls_mpi_init(&T); + + /* Export E */ + if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + + /* Export N */ + if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 || + (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { + goto end_of_export; + } + len += ret; + +end_of_export: + + mbedtls_mpi_free(&T); + if (ret < 0) { + return ret; + } + + MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); + MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE)); + + return (int) len; +} #if defined(MBEDTLS_PKCS1_V15) && defined(MBEDTLS_RSA_C) && !defined(MBEDTLS_RSA_ALT) @@ -688,339 +1020,6 @@ static int asn1_get_nonzero_mpi(unsigned char **p, return 0; } -int mbedtls_rsa_key_parse(mbedtls_rsa_context *rsa, const unsigned char *key, size_t keylen) -{ - int ret, version; - size_t len; - unsigned char *p, *end; - - mbedtls_mpi T; - mbedtls_mpi_init(&T); - - p = (unsigned char *) key; - end = p + keylen; - - /* - * This function parses the RSAPrivateKey (PKCS#1) - * - * RSAPrivateKey ::= SEQUENCE { - * version Version, - * modulus INTEGER, -- n - * publicExponent INTEGER, -- e - * privateExponent INTEGER, -- d - * prime1 INTEGER, -- p - * prime2 INTEGER, -- q - * exponent1 INTEGER, -- d mod (p-1) - * exponent2 INTEGER, -- d mod (q-1) - * coefficient INTEGER, -- (inverse of q) mod p - * otherPrimeInfos OtherPrimeInfos OPTIONAL - * } - */ - if ((ret = mbedtls_asn1_get_tag(&p, end, &len, - MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { - return ret; - } - - end = p + len; - - if ((ret = mbedtls_asn1_get_int(&p, end, &version)) != 0) { - return ret; - } - - if (version != 0) { - return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; - } - - /* Import N */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = mbedtls_rsa_import(rsa, &T, NULL, NULL, - NULL, NULL)) != 0) { - goto cleanup; - } - - /* Import E */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL, - NULL, &T)) != 0) { - goto cleanup; - } - - /* Import D */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = mbedtls_rsa_import(rsa, NULL, NULL, NULL, - &T, NULL)) != 0) { - goto cleanup; - } - - /* Import P */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = mbedtls_rsa_import(rsa, NULL, &T, NULL, - NULL, NULL)) != 0) { - goto cleanup; - } - - /* Import Q */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = mbedtls_rsa_import(rsa, NULL, NULL, &T, - NULL, NULL)) != 0) { - goto cleanup; - } - -#if !defined(MBEDTLS_RSA_NO_CRT) && !defined(MBEDTLS_RSA_ALT) - /* - * The RSA CRT parameters DP, DQ and QP are nominally redundant, in - * that they can be easily recomputed from D, P and Q. However by - * parsing them from the PKCS1 structure it is possible to avoid - * recalculating them which both reduces the overhead of loading - * RSA private keys into memory and also avoids side channels which - * can arise when computing those values, since all of D, P, and Q - * are secret. See https://eprint.iacr.org/2020/055 for a - * description of one such attack. - */ - - /* Import DP */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = mbedtls_mpi_copy(&rsa->DP, &T)) != 0) { - goto cleanup; - } - - /* Import DQ */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = mbedtls_mpi_copy(&rsa->DQ, &T)) != 0) { - goto cleanup; - } - - /* Import QP */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = mbedtls_mpi_copy(&rsa->QP, &T)) != 0) { - goto cleanup; - } - -#else - /* Verify existence of the CRT params */ - if ((ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0 || - (ret = asn1_get_nonzero_mpi(&p, end, &T)) != 0) { - goto cleanup; - } -#endif - - /* rsa_complete() doesn't complete anything with the default - * implementation but is still called: - * - for the benefit of alternative implementation that may want to - * pre-compute stuff beyond what's provided (eg Montgomery factors) - * - as is also sanity-checks the key - * - * Furthermore, we also check the public part for consistency with - * mbedtls_pk_parse_pubkey(), as it includes size minima for example. - */ - if ((ret = mbedtls_rsa_complete(rsa)) != 0 || - (ret = mbedtls_rsa_check_pubkey(rsa)) != 0) { - goto cleanup; - } - - if (p != end) { - ret = MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; - } - -cleanup: - - mbedtls_mpi_free(&T); - - if (ret != 0) { - mbedtls_rsa_free(rsa); - } - - return ret; -} - -int mbedtls_rsa_pubkey_parse(mbedtls_rsa_context *rsa, unsigned char **p, - const unsigned char *end) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t len; - - /* - * RSAPublicKey ::= SEQUENCE { - * modulus INTEGER, -- n - * publicExponent INTEGER -- e - * } - */ - - if ((ret = mbedtls_asn1_get_tag(p, end, &len, - MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) { - return ret; - } - - if (*p + len != end) { - return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; - } - - /* Import N */ - if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) { - return ret; - } - - if ((ret = mbedtls_rsa_import_raw(rsa, *p, len, NULL, 0, NULL, 0, - NULL, 0, NULL, 0)) != 0) { - return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; - } - - *p += len; - - /* Import E */ - if ((ret = mbedtls_asn1_get_tag(p, end, &len, MBEDTLS_ASN1_INTEGER)) != 0) { - return ret; - } - - if ((ret = mbedtls_rsa_import_raw(rsa, NULL, 0, NULL, 0, NULL, 0, - NULL, 0, *p, len)) != 0) { - return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; - } - - *p += len; - - if (mbedtls_rsa_complete(rsa) != 0 || - mbedtls_rsa_check_pubkey(rsa) != 0) { - return MBEDTLS_ERR_RSA_BAD_INPUT_DATA; - } - - if (*p != end) { - return MBEDTLS_ERR_ASN1_LENGTH_MISMATCH; - } - - return 0; -} - -int mbedtls_rsa_key_write(const mbedtls_rsa_context *rsa, unsigned char *start, - unsigned char **p) -{ - size_t len = 0; - int ret; - - mbedtls_mpi T; /* Temporary holding the exported parameters */ - - /* - * Export the parameters one after another to avoid simultaneous copies. - */ - - mbedtls_mpi_init(&T); - - /* Export QP */ - if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - - /* Export DQ */ - if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - - /* Export DP */ - if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - - /* Export Q */ - if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, &T, NULL, NULL)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - - /* Export P */ - if ((ret = mbedtls_rsa_export(rsa, NULL, &T, NULL, NULL, NULL)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - - /* Export D */ - if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, &T, NULL)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - - /* Export E */ - if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - - /* Export N */ - if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - -end_of_export: - - mbedtls_mpi_free(&T); - if (ret < 0) { - return ret; - } - - MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, start, 0)); - MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); - MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, - MBEDTLS_ASN1_CONSTRUCTED | - MBEDTLS_ASN1_SEQUENCE)); - - return (int) len; -} - -/* - * RSAPublicKey ::= SEQUENCE { - * modulus INTEGER, -- n - * publicExponent INTEGER -- e - * } - */ -int mbedtls_rsa_pubkey_write(const mbedtls_rsa_context *rsa, unsigned char *start, - unsigned char **p) -{ - int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t len = 0; - mbedtls_mpi T; - - mbedtls_mpi_init(&T); - - /* Export E */ - if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - - /* Export N */ - if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 || - (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) { - goto end_of_export; - } - len += ret; - -end_of_export: - - mbedtls_mpi_free(&T); - if (ret < 0) { - return ret; - } - - MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len)); - MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | - MBEDTLS_ASN1_SEQUENCE)); - - return (int) len; -} - #if defined(MBEDTLS_GENPRIME) /*