The PKWM trusted source uses a single wrapping key per LPAR, created only once during trust source initialization. All the wrap and unwrap requests are bound to this default wrapping key.
Implement H_PKS_REVOKE_OBJECT, H_PKS_UNREVOKE_OBJECT, and H_PKS_GET_OBJECTLABELS HCALLs to enable support for revoking and unrevoking PKWM wrapping keys, and for retrieving wrapping key labels. The label retrieval operation (H_PKS_GET_OBJECTLABELS) applies to all wrapping keys including the default one, while the life cycle operations (H_PKS_REVOKE_OBJECT/H_PKS_UNREVOKE_OBJECT) apply only to user-created wrapping keys. Signed-off-by: Srish Srinivasan <[email protected]> --- Documentation/arch/powerpc/papr_hcalls.rst | 33 ++ arch/powerpc/include/asm/hvcall.h | 5 +- arch/powerpc/include/asm/plpks.h | 15 + arch/powerpc/platforms/pseries/plpks.c | 475 ++++++++++++++++++++- 4 files changed, 524 insertions(+), 4 deletions(-) diff --git a/Documentation/arch/powerpc/papr_hcalls.rst b/Documentation/arch/powerpc/papr_hcalls.rst index 44c9c8b32ae3..3455b403a048 100644 --- a/Documentation/arch/powerpc/papr_hcalls.rst +++ b/Documentation/arch/powerpc/papr_hcalls.rst @@ -343,6 +343,39 @@ is returned to the caller. H_PKS_UNWRAP_OBJECT is used to unwrap an object that was previously wrapped with H_PKS_WRAP_OBJECT. +**H_PKS_REVOKE_OBJECT** + +| Input: authorization, objectlabel, objectlabellen, flags +| Out: *object policy* +| Return Value: *H_Success, H_Function, H_State, H_Parameter, H_P2, H_P3, H_P4, + H_Authority, H_Not_Found, H_Busy, H_Aborted* + +H_PKS_REVOKE_OBJECT is used to revoke an object in Platform Keystore. + + +**H_PKS_UNREVOKE_OBJECT** + +| Input: authorization, objectlabel, objectlabellen, flags +| Out: *object policy* +| Return Value: *H_Success, H_Function, H_State, H_Parameter, H_P2, H_P3, H_P4, + H_Authority, H_Not_Found, H_Busy, H_Aborted* + +H_PKS_UNREVOKE_OBJECT is used to unrevoke an object that was previously revoked +with H_PKS_REVOKE_OBJECT in Platform Keystore. + + +**H_PKS_GET_OBJECTLABELS** + +| Input: authorization, continueToken, out, outlen +| Out: *continue-token, number of object labels in the returned list, object + label list* +| Return Value: *H_Success, H_Function, H_State, H_Parameter, H_P2, H_P3, H_P4, + H_Authority, H_Busy, H_Aborted, H_Continue* + +H_PKS_GET_OBJECTLABELS is used to retrieve a list of object labels owned by the +specified consumer. + + References ========== .. [1] "Power Architecture Platform Reference" diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index dff90a7d7f70..4d4c2ce1dd87 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -340,6 +340,7 @@ #define H_PKS_GET_CONFIG 0x41C #define H_PKS_SET_PASSWORD 0x420 #define H_PKS_GEN_PASSWORD 0x424 +#define H_PKS_GET_OBJECTLABELS 0x428 #define H_PKS_WRITE_OBJECT 0x42C #define H_PKS_GEN_KEY 0x430 #define H_PKS_READ_OBJECT 0x434 @@ -362,7 +363,9 @@ #define H_GUEST_DELETE 0x488 #define H_PKS_WRAP_OBJECT 0x490 #define H_PKS_UNWRAP_OBJECT 0x494 -#define MAX_HCALL_OPCODE H_PKS_UNWRAP_OBJECT +#define H_PKS_REVOKE_OBJECT 0x4AC +#define H_PKS_UNREVOKE_OBJECT 0x4B0 +#define MAX_HCALL_OPCODE H_PKS_UNREVOKE_OBJECT /* Scope args for H_SCM_UNBIND_ALL */ #define H_UNBIND_SCOPE_ALL (0x1) diff --git a/arch/powerpc/include/asm/plpks.h b/arch/powerpc/include/asm/plpks.h index 8b2ffb27db5a..c39d1f07017e 100644 --- a/arch/powerpc/include/asm/plpks.h +++ b/arch/powerpc/include/asm/plpks.h @@ -25,6 +25,7 @@ #define PLPKS_SIGNEDUPDATE PPC_BIT32(7) // Object can only be modified by signed updates #define PLPKS_WRAPPINGKEY PPC_BIT32(8) // Object contains a wrapping key #define PLPKS_HVPROVISIONED PPC_BIT32(28) // Hypervisor has provisioned this object +#define PLPKS_REVOKED PPC_BIT32(30) // Object is revoked // Signature algorithm flags from signed_update_algorithms #define PLPKS_ALG_RSA2048 PPC_BIT(0) @@ -123,6 +124,20 @@ int plpks_wrap_object(u8 **input_buf, u64 input_len, u16 wrap_flags, int plpks_unwrap_object(u8 **input_buf, u64 input_len, u8 **output_buf, u64 *output_len); + +int plpks_revoke_wrapping_key(struct plpks_var *var); + +int plpks_unrevoke_wrapping_key(struct plpks_var *var); + +int plpks_del_wrapping_key(struct plpks_var *var); + +int plpks_is_wrapping_key_revoked(struct plpks_var *var); + +int plpks_get_object_labels(u8 **output_buf, u64 *output_len, + char *comp_prefix); + +bool plpks_revoke_is_supported(void); + #else // CONFIG_PSERIES_PLPKS static inline bool plpks_is_available(void) { return false; } static inline u16 plpks_get_passwordlen(void) { BUILD_BUG(); } diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c index b553f7b130b6..48a86497eb2b 100644 --- a/arch/powerpc/platforms/pseries/plpks.c +++ b/arch/powerpc/platforms/pseries/plpks.c @@ -23,8 +23,17 @@ */ #define PLPKS_WRAPPING_BUF_DIFF 1024 +/* + * Maximum length for the buffer to store the retrieved object labels + */ +#define PLPKS_OBJLABEL_BUF_MAX 2550 + +#define PLPKS_OBJLABEL_LEN_FIELD_SIZE 2 +#define PLPKS_OBJLABEL_PREFIX_LEN 8 + #define PLPKS_WRAP_INTERFACE_BIT 3 #define PLPKS_WRAPPING_KEY_LENGTH 32 +#define PLPKS_REVOKE_INTERFACE_BIT 4 #define WRAPFLAG_BE_BIT_SET(be_bit) \ BIT_ULL(63 - (be_bit)) @@ -46,6 +55,7 @@ #include <linux/libfdt.h> #include <linux/memblock.h> #include <linux/bitfield.h> +#include <linux/unaligned.h> #include <asm/hvcall.h> #include <asm/machdep.h> #include <asm/plpks.h> @@ -67,6 +77,7 @@ static u32 maxlargeobjectsize; static u64 signedupdatealgorithms; static u64 wrappingfeatures; static bool wrapsupport; +static bool revokesupport; struct plpks_auth { u8 version; @@ -146,6 +157,9 @@ static int pseries_status_to_err(int rc) case H_ABORTED: err = -EIO; break; + case H_CONTINUE: + err = -EAGAIN; + break; default: err = -EINVAL; } @@ -312,6 +326,7 @@ static int _plpks_get_config(void) signedupdatealgorithms = be64_to_cpu(config->signedupdatealgorithms); wrappingfeatures = be64_to_cpu(config->wrappingfeatures); wrapsupport = config->flags & PPC_BIT8(PLPKS_WRAP_INTERFACE_BIT); + revokesupport = config->flags & PPC_BIT8(PLPKS_REVOKE_INTERFACE_BIT); // Validate that the numbers we get back match the requirements of the spec if (maxpwsize < 32) { @@ -831,9 +846,6 @@ static int plpks_read_var(u8 consumer, struct plpks_var *var) if (var->namelen > PLPKS_MAX_NAME_SIZE) return -EINVAL; - if (var->policy & PLPKS_WRAPPINGKEY) - return -EPERM; - auth = construct_auth(consumer); if (IS_ERR(auth)) return PTR_ERR(auth); @@ -903,6 +915,23 @@ bool plpks_wrapping_is_supported(void) } EXPORT_SYMBOL_GPL(plpks_wrapping_is_supported); +/** + * plpks_revoke_is_supported() - Get the H_PKS_REVOKE_OBJECT and + * H_PKS_UNREVOKE_OBJECT interfaces availability status for the LPAR. + * + * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization + * sets bit 4 of the flags variable in the PLPKS config structure if the + * H_PKS_REVOKE_OBJECT and H_PKS_UNREVOKE_OBJECT interfaces are supported. + * + * Returns: true if the H_PKS_REVOKE_OBJECT and H_PKS_UNREVOKE_OBJECT interfaces + * are supported, false if not. + */ +bool plpks_revoke_is_supported(void) +{ + return revokesupport; +} +EXPORT_SYMBOL_GPL(plpks_revoke_is_supported); + /** * plpks_gen_wrapping_key() - Generate a new random key with the 'wrapping key' * policy set. @@ -1189,6 +1218,446 @@ int plpks_unwrap_object(u8 **input_buf, u64 input_len, u8 **output_buf, } EXPORT_SYMBOL_GPL(plpks_unwrap_object); +/** + * plpks_revoke_wrapping_key() - Revoke a wrapping key stored in the PLPKS. + * @var: variable representing the wrapping key to be revoked + * + * The H_PKS_REVOKE_OBJECT HCALL revokes an object stored in the PLPKS. + * + * Possible reasons for the returned errno values: + * + * -ENXIO if PLPKS is not supported + * -EIO if PLPKS access is blocked due to the LPAR's state + * if PLPKS modification is blocked due to the LPAR's state + * if an error occurred while processing the request + * -EINVAL if invalid authorization parameter + * if invalid wrapping key label parameter + * if invalid wrapping key label length parameter + * if invalid or unsupported wrapping key revoking flags + * -EPERM if access is denied + * -ENOENT if the requested wrapping key was not found + * -EBUSY if unable to handle the request or long running operation + * initiated, retry later. + * + * Returns: On success 0 is returned, a negative errno if not. + */ +int plpks_revoke_wrapping_key(struct plpks_var *var) +{ + unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = { 0 }; + struct plpks_auth *auth = NULL; + struct label *label; + u64 objrevokeflags = 0; + int rc = 0, pseries_status = 0; + + if (!var->name || !*var->name) { + pr_err("key label cannot be NULL/empty\n"); + rc = -EINVAL; + goto out; + } + + if (!strcmp((char *)var->name, PLPKS_DEFAULT_WRAPKEY_LABEL)) { + pr_warn("the default wrapping key must not be revoked!\n"); + rc = -EPERM; + goto out; + } + + auth = construct_auth(PLPKS_OS_OWNER); + if (IS_ERR(auth)) { + rc = PTR_ERR(auth); + goto out; + } + + label = construct_label(var->component, var->os, var->name, + var->namelen); + if (IS_ERR(label)) { + rc = PTR_ERR(label); + goto out; + } + + rc = plpar_hcall(H_PKS_REVOKE_OBJECT, retbuf, virt_to_phys(auth), + virt_to_phys(label), label->size, objrevokeflags); + + pseries_status = rc; + rc = pseries_status_to_err(rc); + + if (rc) { + pr_err("H_PKS_REVOKE_OBJECT failed. pseries_status=%d, rc=%d\n", + pseries_status, rc); + } + + if (!rc || (rc == -EPERM && retbuf[0])) + var->policy = (u32)retbuf[0]; + + kfree(label); +out: + kfree(auth); + return rc; +} +EXPORT_SYMBOL_GPL(plpks_revoke_wrapping_key); + +/** + * plpks_unrevoke_wrapping_key() - Unrevoke a revoked wrapping key in the PLPKS. + * @var: variable representing the revoked wrapping key to be unrevoked + * + * The H_PKS_UNREVOKE_OBJECT HCALL unrevokes a revoked object stored in the + * PLPKS. + * + * Possible reasons for the returned errno values: + * + * -ENXIO if PLPKS is not supported + * -EIO if PLPKS access is blocked due to the LPAR's state + * if PLPKS modification is blocked due to the LPAR's state + * if an error occurred while processing the request + * -EINVAL if invalid authorization parameter + * if invalid object label parameter + * if invalid object label length parameter + * if invalid or unsupported object revoking flags + * -EPERM if access is denied + * -ENOENT if the requested object was not found + * -EBUSY if unable to handle the request or long running operation + * initiated, retry later. + * + * Returns: On success 0 is returned, a negative errno if not. + */ +int plpks_unrevoke_wrapping_key(struct plpks_var *var) +{ + unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = { 0 }; + struct plpks_auth *auth = NULL; + struct label *label; + u64 objrevokeflags = 0; + int rc = 0, pseries_status = 0; + + if (!var->name || !*var->name) { + pr_err("key label cannot be NULL/empty\n"); + rc = -EINVAL; + goto out; + } + + if (!strcmp((char *)var->name, PLPKS_DEFAULT_WRAPKEY_LABEL)) { + pr_warn("unrevoke on the default wrapping key is invalid\n"); + rc = -EINVAL; + goto out; + } + + auth = construct_auth(PLPKS_OS_OWNER); + if (IS_ERR(auth)) { + rc = PTR_ERR(auth); + goto out; + } + + label = construct_label(var->component, var->os, var->name, + var->namelen); + if (IS_ERR(label)) { + rc = PTR_ERR(label); + goto out; + } + + rc = plpar_hcall(H_PKS_UNREVOKE_OBJECT, retbuf, + virt_to_phys(auth), virt_to_phys(label), + label->size, objrevokeflags); + + pseries_status = rc; + rc = pseries_status_to_err(rc); + + if (rc) + pr_err("H_PKS_UNREVOKE_OBJECT failed. pseries_status=%d, rc=%d\n", + pseries_status, rc); + + if (!rc || (rc == -EPERM && retbuf[0])) + var->policy = (u32)retbuf[0]; + + kfree(label); +out: + kfree(auth); + return rc; +} +EXPORT_SYMBOL_GPL(plpks_unrevoke_wrapping_key); + +/** + * plpks_is_wrapping_key_revoked() - Check if a given wrapping key has been + * revoked. + * @var: variable representing the wrapping key to be checked + * + * When the H_PKS_READ_OBJECT HCALL tries reads an object that exists but when + * the policy is not met, it returns H_AUTHORITY along with the 4-byte object + * policy. This policy is inspected to determine if the object has been revoked. + * + * Possible reasons for the returned errno values: + * + * -ENXIO if PLPKS is not supported + * -EIO if PLPKS access is blocked due to the LPAR's state + * if an error occurred while processing the request + * -EINVAL if invalid authorization parameter + * if invalid object label parameter + * if invalid object label len parameter + * if invalid output data parameter + * if invalid output data len parameter + * -EPERM if access is denied + * -ENOENT if the requested object was not found + * -EFBIG if the requested object couldn't be + * stored in the buffer provided + * -EBUSY if unable to handle the request + * + * Returns: 1 is returned if the wrapping key has been revoked. 0 is returned if + * the wrapping key has not been revoked. Otherwise, a negative errno + * is returned. + */ +int plpks_is_wrapping_key_revoked(struct plpks_var *var) +{ + int rc; + + if (!var->name || !*var->name) { + pr_err("key label cannot be NULL/empty\n"); + rc = -EINVAL; + goto out; + } + + rc = plpks_read_var(PLPKS_OS_OWNER, var); + if (!rc) { + pr_err("unexpected successful read of wrapping key\n"); + rc = -EIO; + } else if (rc == -EPERM) { + if (var->policy & PLPKS_WRAPPINGKEY) { + if (var->policy & PLPKS_REVOKED) + rc = 1; + else + rc = 0; + } + } + +out: + return rc; +} +EXPORT_SYMBOL_GPL(plpks_is_wrapping_key_revoked); + +/** + * plpks_del_wrapping_key() - Delete a wrapping key from the PLPKS. + * @var: variable representing the revoked wrapping key to be deleted + * + * The plpks_remove_var function removes the specified variable and its data + * from the PLPKS by invoking the H_PKS_REMOVE_OBJECT HCALL. + * + * Possible reasons for the returned errno values: + * + * -ENXIO if PLPKS is not supported + * -EIO if PLPKS access is blocked due to the LPAR's state + * if PLPKS modification is blocked due to the LPAR's state + * if an error occurred while processing the request + * -EINVAL if invalid authorization parameter + * if invalid object label parameter + * if invalid object label len parameter + * -EPERM if access is denied + * -ENOENT if the requested object was not found + * -EBUSY if unable to handle the request + * + * Returns: On success 0 is returned, a negative errno if not. + */ +int plpks_del_wrapping_key(struct plpks_var *var) +{ + int rc; + struct plpks_var_name vname; + + if (!var->name || !*var->name) { + pr_err("key label cannot be NULL/empty\n"); + rc = -EINVAL; + goto out; + } + + if (!strcmp((char *)var->name, PLPKS_DEFAULT_WRAPKEY_LABEL)) { + pr_warn("the default wrapping key must not be deleted!\n"); + rc = -EPERM; + goto out; + } + + rc = plpks_is_wrapping_key_revoked(var); + if (rc == 1) { + vname = (struct plpks_var_name) { + .name = var->name, + .namelen = var->namelen + }; + + rc = plpks_remove_var(PLPKS_WRAPKEY_COMPONENT, var->os, + vname); + if (rc) + pr_err("deletion of <%s> failed. rc=%d\n", + (char *)var->name, rc); + goto out; + } else if (!rc) { + pr_err("revoke <%s> before deletion\n", (char *)var->name); + rc = -EPERM; + goto out; + } else { + pr_err("revocation status check failed for <%s>. rc = %d\n", + (char *)var->name, rc); + } + +out: + return rc; +} +EXPORT_SYMBOL_GPL(plpks_del_wrapping_key); + +/** + * plpks_get_object_labels() - retrieve a list of object labels for the objects + * stored in the PLPKS + * @output_buf: buffer to store the retrieved object labels + * @output_len: number of object labels retrieved + * @comp_prefix: component prefix string + * + * The H_PKS_GET_OBJECTLABELS HCALL retrieves a list of object labels for the + * objects with the given component prefix stored in the PLPKS. + * + * Possible reasons for the returned errno values: + * + * -ENXIO if PLPKS is not supported + * -EIO if PLPKS access is blocked due to the LPAR's state + * if PLPKS modification is blocked due to the LPAR's state + * if an error occurred while processing the request + * -EINVAL if invalid authorization parameter + * if invalid output buffer parameter + * if invalid output buffer length parameter + * if invalid continue token parameter + * if the provided component prefix is NULL + * -EPERM if access is denied + * -EBUSY if unable to handle the request or long running operation + * initiated, retry later. + * + * Returns: On success 0 is returned, a negative errno if not. + */ +int plpks_get_object_labels(u8 **output_buf, u64 *output_len, + char *comp_prefix) +{ + unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = { 0 }; + u8 *labels_buf = NULL; + u8 *tmp_buf = NULL; + struct plpks_auth *auth = NULL; + struct label_attr *metadata = NULL; + u16 label_len; + u64 labels_count; + u64 continuetoken = 0, output_buf_len = 0; + int rc = 0, pseries_status = 0; + size_t labels_buf_offset = 0, output_buf_offset = 0; + size_t obj_label_entry_size, i; + + *output_buf = NULL; + *output_len = 0; + + if (!comp_prefix) { + rc = -EINVAL; + goto out; + } + + auth = construct_auth(PLPKS_OS_OWNER); + if (IS_ERR(auth)) { + rc = PTR_ERR(auth); + goto out; + } + + do { + labels_buf = + kzalloc(roundup_pow_of_two(PLPKS_OBJLABEL_BUF_MAX), + GFP_KERNEL); + + if (!labels_buf) { + pr_err("labels_buf buffer allocation failed\n"); + rc = -ENOMEM; + goto out_free_output_buf; + } + + rc = plpar_hcall(H_PKS_GET_OBJECTLABELS, retbuf, + virt_to_phys(auth), continuetoken, + virt_to_phys(labels_buf), + roundup_pow_of_two(PLPKS_OBJLABEL_BUF_MAX)); + + pseries_status = rc; + rc = pseries_status_to_err(rc); + + if (rc && rc != -EAGAIN) { + pr_err("H_PKS_GET_OBJECTLABELS failed. pseries_status=%d rc=%d\n", + pseries_status, rc); + goto out_free_labels_buf; + } else { + /* + * Setting an incorrect countinuetoken upon + * receiving H_CONTINUE would result in H_P2. Since + * the continuetoken is being set to the expected + * value from the previous call, H_P2 must not be + * returned. + */ + continuetoken = retbuf[1]; + + labels_count = retbuf[0]; + if (!labels_count) { + kfree(labels_buf); + labels_buf = NULL; + goto out; + } + + /* + * Filter out object labels that don't have the provided + * component prefix. + */ + + output_buf_len += + roundup_pow_of_two(PLPKS_OBJLABEL_BUF_MAX); + + tmp_buf = krealloc(*output_buf, output_buf_len, + GFP_KERNEL); + + if (!tmp_buf) { + pr_err("output buffer re-allocation failed\n"); + rc = -ENOMEM; + goto out_free_labels_buf; + } + + *output_buf = tmp_buf; + + for (i = 0; i < labels_count; ++i) { + label_len = + get_unaligned_be16(labels_buf + + labels_buf_offset); + + obj_label_entry_size = + PLPKS_OBJLABEL_LEN_FIELD_SIZE + + label_len; + + metadata = + (struct label_attr *)(labels_buf + + labels_buf_offset + + PLPKS_OBJLABEL_LEN_FIELD_SIZE); + + if (!memcmp(metadata->prefix, comp_prefix, + PLPKS_OBJLABEL_PREFIX_LEN)) { + memcpy(*output_buf + output_buf_offset, + labels_buf + labels_buf_offset, + obj_label_entry_size); + + output_buf_offset += + obj_label_entry_size; + (*output_len) += 1; + } + labels_buf_offset += obj_label_entry_size; + } + kfree(labels_buf); + labels_buf = NULL; + labels_buf_offset = 0; + } + } while (rc == -EAGAIN); + + goto out; + +out_free_labels_buf: + kfree(labels_buf); + labels_buf = NULL; +out_free_output_buf: + kfree(*output_buf); + *output_buf = NULL; + *output_len = 0; +out: + kfree(auth); + return rc; +} +EXPORT_SYMBOL_GPL(plpks_get_object_labels); + /** * plpks_read_os_var() - Fetch the data for the specified variable that is owned * by the OS consumer. -- 2.52.0
